.Compressed Air Systems and Performance Efficiency
Pressure drop is a crucial aspect of compressed-air technology that is often overlooked. It is defined as the reduction in air pressure from the compressor discharge to the point of use. And is caused by resistance encountered by the compressed air as it moves through the system’s components. This includes pipes, valves, and fittings. Even a minor pressure drop can significantly reduce the system’s efficiency and operational cost. If achieving a high-performance compressed air system is the goal. Then it is essential to have a thorough understanding of pressure drop and its management.
The impact of pressure drop goes beyond technical glitches, affecting the system’s efficiency and operational costs. A higher pressure drop necessitates the compressor to work harder to maintain the required pressure. Leading to increased energy consumption and a larger carbon footprint. Additionally, a significant pressure drop can negatively impact the functioning of air-operated equipment, leading to inferior product quality and reduced productivity.
Compressed Air Systems and Performance Efficiency
Pressure drop particularly affects the performance of engineered air nozzles and air knives used for blow off and cleaning applications. Pressure drop particularly affects them.
These specialized tools require a steady, precise pressure to operate optimally. A pressure drop can lead to inadequate performance, resulting in less effective blow off, cleaning, or cooling applications. For instance, an air knife used to strip away excess liquid or debris may fall short, leaving residues that could compromise the quality of the final product or the efficiency of subsequent processes.
Prevention and consistent monitoring are the two-pronged approach to addressing pressure drop. Prevention involves designing a system that minimizes resistance by employing larger diameter pipes, minimizing bends in the piping, and opting for low-resistance components. Regular maintenance to eliminate leaks and blockages further reduces pressure drop and prolongs the system’s lifespan. Monitoring via pressure gauges, flow meters, and real-time monitoring equipment can unveil and help rectify pressure drop issues, ensuring the engineered air nozzles and air knives perform as intended.
In conclusion, pressure drop in compressed air systems is a critical factor that warrants meticulous attention. By understanding its implications and adopting a vigilant approach towards prevention and monitoring, operators can significantly improve the efficiency and reliability of compressed air systems. Timely addressing of pressure drop issues translates to energy savings and a more sustainable and productive operational environment, ensuring that engineered air nozzles and air knives function optimally to uphold the highest standards of quality and efficiency.
Seven Ways to make your Compressed Air Blow off and Cooling More Efficient
The majority of compressed air is used for blow off and cooling despite the push for alternate technologies like blowers simply because it is still the most efficient to use in a given application, either because of inadequate pressure from blowers, space problems or high capital and maintenance costs.
This is the reality and which is why compressed air use continues to grow.
So how can you make your compressed air use more efficient for blow off and cooling?
Look at the compressor room – do you need to address the air supply system efficiency? Can you reduce air compressor unloaded times? A great deal of developments in air compressor technology itself can improve overall supply efficiency which in turn increases end use efficiency. Is it the correct size and type for your factory use? Setting the maximum compressed air pressure to a lower level without harming downstream pressure requirements also reduces costs. Every 10 PSIG pressure reduction saves approximately 5% in energy savings.
Fix leaks- but not just pipe leaks, leaks at worn connectors which should be replaced, stuck auto drains on filters, even unsealed connections to air nozzles, air tools and other compressed air operated equipment. Because leaks also lowers downstream and end use available pressure, just fixing any leaks can help reduce the maximum pressure settings at the air compressors.
Check pressure losses – while your factory main compressed air piping maybe adequately sized to minimize pressure loss to the point of use, all too often the connection from the main line to the point of use utilizes piping or hose that is simply too small causing excess pressure loss. This is also compounded with fittings that are too small for the air requirement aggravating pressure loss. It is too common to measure pressure at the main line of 100 PSIG and only three feet away have losses up to 30% simply because the line size from the main to the application was too small. Always check the air requirement (AND pressure requirement of the air nozzle, air knife, vortex tube, panel cooler or any other end use product and be sure that the connection line is of adequate size.
Proper filtration and dryness – when dealing with compressed air blow off and cooling, devices like engineered air nozzles and vortex tubes require clean and dry compressed air. Any dirt buildup over time and excessive moisture negatively affects performance and can even clog the products. Always use point of use filtration to remove any excess moisture and particulate. Inadequate filtration can not only effect the device, it can also impact the quality of the product where any blow off is used.
Consider on-off control – a huge advantage of compressed air is that it can be stored and used on demand. When not used, it remains stored and energy is not consumed. Utilizing sensors and solenoid valves or a system such as the Nex Flow® PLCFC can take advantage of this storage ability which can yield tremendous energy savings. Many production lines do not need to have the blow off and cooling constantly on.
Consider New Pulsing Technology – pulsing of compressed air not new and solenoid valves have been used for years to do this. The problem with solenoid valves is however the high wear and tear and therefore the cost to maintain them typically offsetting any energy savings. It is also not certain how much energy is saved as other factors come into play when pulsing occurs. However, pulsing provides scrubbing action to help clean surfaces and a “push” to move or loosen a target where necessary. New process valves have, and still are being developed for pulsing to overcome these maintenance costs and offer potential for improved cleaning with engineered nozzles and for energy saving when properly applied. has done some projects with pulsing so has experience needed when using new pulse technology and offers consulting services for this as well as other applications.
Stay informed on new technologies for blow off and cooling but beware of false claims – Nex Flow® and a few other companies do research and development to improve products for blow off, cooling and conveying. Many others just copy, (usually not very well) other’s work and sometimes even claim it as their own. To stay focused, Nex Flow® provides compressed air blow off, cooling and conveying products and stays away from things like spray nozzles. Rather than being a supplier of all things, we specialize and share deep knowledge and experience in what we actually know. This is evidenced by our history of success, continued growth and our unique patents of which there are more to come with ongoing R & D and innovation. Be very careful of product claims that make no sense of product performance, some which even defy the laws of physics. Make sure companies that offer blow off and cooling technology can even afford to get proper approvals where necessary such as for control Panel Cooling to be assured they will stay around to service you (and that the product is even legal!). Reliability, timely response, and quality product and service is always important.
With the advent of the Covid 19 pandemic, there has been an acceleration toward automation. Packaging solutions and advances have also become important. Pneumatics plays a very large part in both automation and packaging as outlined below in the blog
Part of pneumatic technology is the use of compressed air for blowing, moving and cooling. The rugged nature and general low cost of compressed air products for these applications as well as the extremely low level of maintenance required have become more important criteria where downtime and maintenance costs have also risen dramatically especially when compared to more complex and expensive capital cost alternatives.
Pneumatic and hydraulic systems have many similarities. Both pneumatics and hydraulics are applications of fluid power. They each use a pump as an actuator, are controlled by valves, and use fluids to transmit mechanical energy. The biggest difference between the two types of systems is the medium used and applications. Pneumatics use an easily compressible gas such as air or other sorts of suitable pure gas—while hydraulics uses relatively incompressible liquid media such as hydraulic or mineral oil, ethylene glycol, water, or high temperature fire-resistant fluids. Neither type of system is more popular than the other because their applications are specialized. This article will help you make a better choice for your application by describing the two types of systems, their applications, advantages, and disadvantages. The load or the force that you need to apply, the output speed, and energy costs determine the type of system you need for your application.
What is Pneumatics?
Pneumatics is a branch of engineering that makes use of pressurized gas or air to affect mechanical motion based on the working principles of fluid dynamics and pressure. The field of pneumatics has changed from small handheld devices to large machines that serve different functions. Pneumatic systems are commonly powered by compressed air or inert gases. The system consists of interconnected set of components including a gas compressor, transition lines, air tanks, hoses, standard cylinders, and gas (atmosphere). The compressed air is supplied by the compressor and transmitted through a series of hoses. The air flow is regulated by manual or automatic solenoid valves and the pneumatic cylinder transfers energy provided by the compressed gas to mechanical energy. A centrally located and electrically powered compressor powers cylinders, air motors, and other pneumatic devices. Pneumatic systems are controlled by a simple ON/OFF switch or valve.
Most industrial pneumatic applications use pressures of about 80 to 100 pounds per square inch (550 to 690 kPa). The compressed air is stored in receiver tanks before it is transmitted for use. The compressors ability to compress the gas is limited by the compression ratios.
Applications
Pneumatic systems are typically used in construction, robotics, food manufacturing and distribution, conveying of materials, medical applications (dentistry), pharmaceutical and biotech, mining, mills, in buildings, and tools in factories. Pneumatic systems are primarily used for shock absorption applications because gas is compressible and allows the equipment to be less susceptible to shock damage.
Applications of pneumatic systems include:
Air compressors
Vacuum pumps
Compressed-air engines and vehicles
HVAC control systems
Conveyor systems in pharmaceutical and food industries
Pressure sensor, switch and pump
Precision drills used by dentists
Air brakes used by buses, trucks, and trains
Tampers used to pack down dirt and gravel
Nail guns
High pressure bank’s drive-teller tubes
Manufacturing and assembly lines
Pneumatic motor, tire, and tools
Advantages and Disadvantages of Pneumatics
Pneumatic systems are selected above hydraulic systems because of the lower cost, flexibility, and higher safety levels of the system. Pneumatic systems are best suited for applications which require no risk of contamination because they offer a very clean environment for such industries as biotech, dentistry, pharmaceutical, and food suppliers. Since they use clean, dry, compressed air, the system can quickly convey items. The straight and simple design prevents clogging and reduces maintenance. Pneumatic systems are easy to install and portable. They are reliable and has an initial low setup cost because they operate on comparatively low pressure and inexpensive components that reduces operation costs.
No container is required to store the air that will be compressed because it is drawn from the surrounding atmosphere and filtered (optional). The entire system is designed using standard cylinders and other components. The air or gas used in a pneumatic system is typically dried and free of moisture so that it does not create issues to internal components.
Pneumatic systems provide rapid movement of cylinders because the air compressor flow rates. Air is very agile and can flow through pipes very easily and quickly with little resistance. Pneumatic systems are available in a wide variety in very small sizes. The pneumatic systems are clean and do not pollute because any exhaust is released into the atmosphere. The Pneumatic system is more agile because if the system needs to change directions, the simple design and control allows operators to update the system quickly without environmental impact.
Pneumatics are cheaper than hydraulic systems because air is inexpensive, plentiful, easy to obtain, and store. Pneumatic systems generally have long operating lives and require little maintenance because gas is compressible, and the equipment is less subject to shock damage. Unlike hydraulic systems that use liquids that transfers force, gas absorbs excessive force.
Safety is an important advantage of choosing Pneumatic systems. Since Pneumatic systems run on compressed air, there is very little chance of fire compared with explosion or fire hazard of using compressed hydraulic oil. It is also maintenance free since there is little need to replace filters.
It is essential to determine the amount of force required for your application because not as much force is created with pneumatic systems as with hydraulic systems. Pneumatic systems do not offer the same potential force as hydraulic systems so they should not be used for applications that require lifting or moving heavy loads. Compressed air experiences air pressure fluctuations, so that movement can be jerky or spongy at times while moving or lifting loads. A larger cylinder is needed to produce the same force that a hydraulic ram can produce. In terms of energy costs, pneumatic systems cost more than hydraulics because the amount of energy lost through heat produced while compressing air. Another significant concern about pneumatic systems is the noise that is created. If used, it is the responsibility of the owners to protect their workers from hearing loss.
What is Hydraulics?
Hydraulics is used for the generation, control, and transmission of power using pressurized liquids. It is a technology and applied science involving mechanical properties and use of liquids. Hydraulic systems require a pump and, like pneumatic systems, uses valves to control the force and velocity of the actuators. Industrial applications of hydraulics use 1 000 to 5 000 psi or more than 10 000 psi for specialized application. The word hydraulics originates from Greek words hydor – water and aulos – pipe. The following equipment is required for a hydraulic system: hydraulic fluid, cylinder, piston, pumps, and valves that control the direction of flow, which is always in one direction.
Hydraulic systems, unlike Pneumatic systems are often large and complex. The system requires more room because a container is required to hold fluid that flows through the system. Since the size of the system is larger, it requires more pressure; making it more expensive than Pneumatic systems. Due to their overall larger size and the incompressibility of oil, hydraulic systems can lift and move larger materials. Hydraulic systems are slower because oil is viscous and requires more energy to move through pipes. During configuration and planning, if the factory or plant has several hydraulic machines, it is ideal to have a central power unit to reduce noise levels.
Applications
Due to the risk of potential hydraulic oil leaks from faulty valves, seals or hoses – hydraulic applications do not apply to anything that would be ingested – such as food and medical applications. They are used in a variety of everyday machine applications:
Elevators
Dams
Machine tools: hydraulic presses, hoppers, cylinders, and rams
Amusement parks
Turbines
Dump truck lift
Wheelchair lift
Excavating arms for diggers
Hydraulic presses for forging metal parts
Wing flaps on aircraft
Hydraulic braking system in cars
Lift cars using a hydraulic lift
Jaws of life
Advantages of Hydraulics
Hydraulic systems are more capable of moving heavier loads and providing higher forces due to the incompressibility of liquids. Hydraulic systems do many purposes at one time, including lubrication, cooling, and power transmission. Hydraulic powered machines operate at higher pressures (1 500 to 2 500 psi), generating higher force from small-scale actuators. To effectively use a hydraulic system, it is essential to pick an appropriately sized component to match the flow.
Hydraulic systems are larger and more complicated systems. Liquid, such as hydraulic oil is viscous and requires more energy to move. A tank is also required to store the oil from which the system can draw from when the oil is reduced. The initial costs are higher than Pneumatic systems because it requires power that needs to be incorporated into the machine.
Any leaks in a hydraulic system can cause serious problems. This system cannot be used for food applications due to high risk of hydraulic oil leaks from faulty seals, valves, or burst hoses. Appropriate plumbing procedures, preventative and regular maintenance, and having the correct materials on hand to minimize potential leaks and to quickly remedy any issues need to be in place at each site. In conclusion, pneumatic devices are best suited to execute low scale engineering and mechanical tasks while hydraulic systems are best for applications that require higher force and heavy lifting.
Summary: In general, it is a good rule of thumb to use hydraulic systems primarily for heavy lifting applications such as the jaws of life, elevators, hydraulic presses and arms in heavy equipment, and wing flaps for airplanes because these types of systems operate at higher pressures (1 500 to 2 500 psi), generating higher force from small-scale actuators. When it comes to moving or manufacturing products, especially food or pharmaceutical, it is recommended to use pneumatic systems because there is no chance of contamination due to burst pipes or oil leaks. Nex Flow Air Products Corporation manufactures compressed air products for blow off, industrial cooling (Vortex Tubes), air operated conveying, and air optimization designed to reduce energy costs while improving safety and increasing productivity in your factory and manufacturing environments.
Engineered air jets, air knives, air amplifiers, and air nozzles are examples of blow off products manufactured and sold by Nex Flow. They are safe because they meet OSHA noise and pressure requirements. Air Amplifiers are recommended for purging tanks, venting fumes, smoke, lightweight materials from automobiles, truck repair, or from other confined spaces. These products are also used to clean and dry parts, remove chips, and part ejection. They can also be used as effective tools for your manufacturing environment.
Vortex tube industrial cooling applications converts compressed air into very cold air for spot cooling. Nex Flow provides Vortex Tubes and Cabinet Enclosure Coolers. These products are ideal for use in high temperature and harsh environments. These products are especially ideal for use in high temperature and harsh environments. They also provide smaller vortex tube operated mini-coolers and vortex cooling for tool cooling systems. These systems can provide extremely cold temperatures without the use of refrigerants, such as CFCs or HCFCs. Industrial vortex tube powered cooling products are recommended for cooling gas samples, heat seals, data centers, electronic and electrical control instruments and environmental chambers.
Compressed air operated pneumatic conveyors are designed to move materials at high rates and over long distances. They are ideal for continuous or intermittent use since they are operated by an on/off switch and controlled by a regulator. Our air operated conveyors are compact and have no moving parts. Nex Flow also provides fume and dust extractors, Ring Vac Operated conveyors and an X-StreamTM Hand Vac system. Air operated pneumatic conveyors are primarily used for conveying materials for applications where vacuum force is required to move objects over long distances at high speeds. These devices have an on/off switch to enhance safety. It uses compressed air, not electricity, so there is no explosion hazard. The Nex Flow Ring Vacs are made of anodized aluminum or stainless steel. They are designed to transport or vent a wide variety of lightweight products, raw materials, or fumes from one place to another in your factory. For high temperature and corrosive applications, regular and high temperature stainless steel is available. When moving food and pharmaceutical products, 316L Stainless Steel pneumatic conveyors are used. The specially design non-clogging model XSPC air operated conveyors are easy to install and use, compact and portable, and maintenance free.
The systems offered by Nex Flow optimize compressed air system operations because of efficient design. The systems can be easily turned on and off so that the compressed air is used only when needed. The products do not have high maintenance costs and are light weight. System optimization can be achieved with the compact sound meter, ultrasonic leak detector and PLC flow control (PLCFC) system for compressed air, which uses photoelectric sensors to turn on the air when the target passes the sensor and to turn off the air when it leaves the sensor or can be set by time. This device can be used for dust and debris blow-off, part drying system, cooling hot parts, and cleaning parts before packaging. Nex Flow offers various accessories that are integrated into pneumatics systems to increase the efficiency of compressed air conveying products and systems. Some accessories include nozzles, mufflers, filters, mounting systems and static control for blow off of dust and debris from statically charged surfaces.
Nex Flow pneumatic products reduce noise, enhance factory safety, and provide excellent venting, cooling, and blow-off solutions. Compressed air conveying systems provides instant response times and are the most efficient and effective way to convert pressure into useful flow. The cost-effective pneumatic conveying systems provided by Nex Flow are simple, light weight, compact, reliable, and easy to install and use. Since there are no moving parts, pockets or angles to collect debris, moisture, or water, the maintenance costs are minimal. Expect the best from Nex Flow technicians, who are trained to help you determine the best solution for your application.
The Nex Flow Difference: Why we treat our materials differently?
Nex Flow Air Products Corp. sets itself apart from its competitors by doing a few things differently with the materials that we use in manufacturing our products. While some producers are actually quite similar in product as to how they deal with material, we stand out in four specific areas as to what we do with the materials of manufacture. Differences for Nex Flow are as follows:
Anodized aluminum parts
Powder coated parts
No Plastic in our vortex tubes
We do not mix aluminum and stainless steel in our vortex tube packages
Anodized Aluminum parts
We make it a point to anodize our aluminum air knives, amplifier, air jets, air wipes and air operated conveyors. It is actually much easier (and certainly less costly) to produce these items without anodizing due to the importance of efficient aerodynamic design. When the products are anodized the surface changes, even if the change is very small, it makes it more difficult to keep a flat part flat (i.e. air knives). But, we CAN do and we do it because of the value the anodizing adds benefits to the products. Anodizing helps guard against the effects of the factory environment on the aluminum. Unprotected aluminum will form a powdering while oxide over time. Anodizing keeps the product looking better and longer even when using dissimilar metals in assembly, stainless shims, stainless screws, with aluminum bodies, it protects the accessories from even minor effects of cathodic corrosion. Cathodic corrosion can occur in a highly humid environment or if the parts get wet. Dissimilar metals can act like a battery where the more active metal can corrode unless there is some form of protection. You can see this effect, for example, with rust around screws used on some buildings or machines because the screws are of one material while the metal it is screwed into is another. When paint wears away, it leaves unprotected metal that is more electrically “active” than the metal in the screw. By anodizing and protecting our product, Nex Flow ensures that our accessories will last longer and look better over time.
Powder Coated parts
Some of our cast zinc parts, specifically our Air Edger flat jet nozzles and cast Fixed X-Stream Air Amplifier, also have powder coating. It provides a much better finish and look to the product and again, extra layer of protection from the factory environment. Powder coating is an excellent protection in a factory environment. Powder coating parts adds intrinsic value to the products to the betterment of the customer providing a product that is longer lasting look better through time.
No Plastic in Vortex Tubes
Most manufacturers of vortex tubes use injection molded plastic “generators” which are used in the unit to initiate the compressed air spinning effect. Nex Flow machines their “brass” generators for that purpose instead of plastic. While plastic would be much less costly, brass offers a few advantages. Injection molding plastic will have some variations in production, especially as the mold wears out. By machining the metal generators we have much greater consistency with the parts which translates into much greater consistency in performance from one vortex tube to the next. Vortex tubes consist of several parts and of course, each part has a certain tolerance in manufacturing. Nex Flow has very tight tolerances on each part and the generators especially require very tight tolerances. The more pieces involved in assembling a part, the more the cumulative effect on the overall variation in tolerance and therefore performance since the operation of all Nex Flow products are based on aerodynamic shapes.
As the generator is such a critical component in a vortex tube, we recognize the need to use metal instead of plastic. Another advantage of using metal, in our case brass, instead of plastic is that plastic can possibly crack over time. If the compressed air supply is dirty the generator can also build up dirt and engrain itself, hence requiring replacement. The metal ones we use are easily cleaned. Sometimes vortex tubes or their packaged versions are used in very hot environments so the parts must be able to hold up in high temperature areas, especially when not operating. In these cases even competitive units replace their plastic generator with metal. Nex Flow vortex tubes and many of their packages are therefore more flexible in the environments where they can be used. While competitors would charge extra for a special product, our standard product can generally be used instead.
We do not mix Aluminum and Stainless Steel
Our vortex tube packages include tool coolers, mini coolers, adjustable coolers, panel coolers, etc. Of particular importance is the materials used in a panel cooler used for cabinet enclosure cooling and camera cooling. Many manufacturers will use a stainless steel vortex tube packages as a control panel cooler using aluminum housing and attachments. While not a problem in relatively benevolent factory environments, it can become an issue in very humid area or in applications where they are used in wash down conditions. Cathodic corrosion can occur described earlier with dissimilar metals with air knives. On one visit to a customer there was actually a competitive vortex tube cooling system with a big hole on the side of the assembly. Cabinet cooling applications are very critical because you do not want any possibility for moisture getting into the control panel. This is the reason vortex coolers should have the proper approvals to insure this does not happen (such as Underwriters Laboratory testing and approval). Cabinet Coolers are essentially vortex tubes with a cover and some system to prevent moisture from getting inside of the cover and possibly then into the cabinet. This cover was aluminum and the vortex tube another material. The environment was a relatively wet environment, so over time cathodic corrosion cause the aluminum to corrode and create a hole in the protective cover. Thus, creating a potential risk for water to get into the electrical cabinet. It is for this very reason (preventing cathodic corrosion) that Nex Flow only has stainless steel covers for their stainless steel vortex tubes. Similarly with all other packages systems, whether they are tool coolers or adjustable coolers, the packages are made with stainless steel only and not a mixture of stainless steel and aluminum.
It’s a Wrap
These are some of the reasons why Nex Flow treats their materials differently. While some of these “differences” in material handling and treatment can be more costly from a manufacturing point of view, they do offer significant added value to the products and a benefit to the customer, and still with a very competitive price.
Wind tunnels are large tubes with air moving inside. These tunnels are used to test models of aircraft or other flying objects on their actions in flight. These models are scaled down versions of actual objects that will be built. Researchers and institutions around the world like NASA, uses wind tunnels to learn more about how an aircraft and spacecraft will fly. But it is not just flying machines that are tested. These Wind chambers are also used to test how an automobile shape, or windshield design will behave in environments with strong winds. Aerodynamics is the study of the flow of air or gases around an object in motion. Essentially these tunnels are hollow tubes with controllable fans at one end to test objects aerodynamics ensuring safety and performance of machines. Airplane builders use NASA wind tunnels to test new airplane designs. Credits: NASA
Frank H. Wenham (1824-1908), along with his colleague John Browning, invented the wind tunnel and built the first one in 1871. He described it as “a trunk 12 feet long and 18 inches square, to direct the current horizontally, and in parallel course.” As a British marine engineer he studied the problems of human flight and had many publications. He also made a huge influence in the development of aeronautics. Their experiments showed that high aspect ratio wings – long and narrow—had a better lift-to-drag ratio than short stubby wings with the same lifting area. Wenham may have been the first scientist to use/coined the word “aeroplane”. Aviation writer Carroll Gray says Wenham’s work may have been an important influence to the Wright brothers.
As mentioned above, wind tunnels typically use powerful fans. But – it is possible to use Nex Flow compressed air operated Air Amplifiers instead of fans for a miniature wind tunnel. To get the system to work, the gap setting on the Air Amplifiers will have to be increased to approach the power needed for testing even a very small object. Although there are limitations to using compressed air for wind tunnel emulation – they do offer some advantages like having a lower noise level and their ability to be combined with vortex tube technology for testing at sub-zero temperatures. Powerful fans overcome back pressure created by the length and overall volume in the tunnel. Compressed air amplifiers however cannot be “revved up” like a motor and are subject to this back pressure limiting the length and volume of a tunnel where it can be used. However for very light and small objects, it is conceivable to use an Air Amplifier to operate a miniature wind tunnel. Air Amplifiers take compressed air that is consumed and converts the pressure normally lost as pressure drop and noise into high velocity and high laminar flow. With fans you can control this velocity and flow by making the fan turn faster or slower. With Air Amplifiers you have some limited control with input pressure but in a much more narrow range which should suffice for a small miniature tunnel. A common setup at exhibitions is to attach an Air Amplifier to a stand and have the amplified airflow support a beach ball which can be held a few feet above the vertically aimed Amplifier. The object tested in an Air Amplifier operated miniature wind tunnel would have to be in the low weight range of a beach ball to be useful. A powerful compressed air operated engineered nozzle, or a series of engineered air nozzles might be paced at one end of a miniature wind tunnel for more force. After a short distance, the combined airflow could produce enough velocity and flow to be useful for testing small, light objects. One advantage of both using compressed air amplifiers or laminar nozzle is the lower noise level than you would get from a powerful fan.
Vortex tube technology however, does offer one advantage for a special type of wind tunnel. A vortex tube is a device which takes compressed air and divides it up into a hot and cold stream. This cold stream of air flow can go to very low, sub-zero temperatures. Vortex tube commercially are available in air consumption ranges of 2 to 150 SCFM. However, there is no reason that a vortex tube cannot be made much larger to consume several thousand SCFM. In some research applications for wind tunnels it is necessary to study aerodynamics at sub-zero temperatures (i.e. the behavior of military aircraft in arctic or subarctic conditions). A much larger vortex tube consuming one thousand SCFM or even more can produce very cold temperatures of -40 ˚C and even colder if the compressed air supply is cooled further. While it would seem to be uneconomical to use such high volumes of compressed air, that high energy cost is offset by the fact that you do not have to cool the air to the sub-zero temperatures required for testing. Also, the efficiency in the production of the cold temperature actually goes up as you increase the size of the vortex tube. Let’s presume you have 10,000 SCFM of compressed air supply. With vortex tubes the temperature drop increases (you get colder temperatures) the more air you exhaust at the “hot end”. So if only 30% (3000 SCFM) goes out the cold end to get that -40 degrees Celsius. The cost of cooing 3000 SCFM of a fan produced air flow to that cold temperature using a more traditional means of cooling will be very high. You also will be using refrigerant which will be costly, and need maintenance. In using a special vortex tube you only have the compressors and the wind tunnel taking the flow, at the low temperatures you want. This minimizes any maintenance involved. It is actually a very simple system.
So while there are certainly not a great deal of applications where a wind tunnel is needed that produces such low sub-zero temperature airflow, there are certainly enough when dealing with some military and space equipment applications where aerodynamic tests results under extremely low temperatures are required. In this case, using a special large vortex tube is a possibility. Such special wind tunnel has been built in the past with very large vortex tube design.
For unique applications such as the above – Nex Flow has experience in special vortex tube design. Some years ago a two meter long vortex tube was developed for an application (not a wind tunnel however) which used natural gas as the medium instead of compressed air. The parameters of the application had to be addressed to develop the optimum design and the supply gas was at very high pressure. The application remains proprietary but it does indicate that vortex tube technology can be adapted and made effective and economical for special applications where cold temperatures or overall cooling is necessary and where using traditional cooling would not be as effective or economical.
So for wind tunnel applications, Air Amplifiers (and even Engineered Air Nozzles or jets) can apply to miniature wind tunnel for small and lightweight objects. If the wind tunnel requires sub-zero temperatures, vortex tube can be integrated as part of the system. Do note that as these are two different things entirely, you connect a vortex tube to an air amplifier
There are many compressed air operated blow guns on the market with the vast majority being ¼” or 1/8” meant for light to medium use in production and cleaning applications. They vary greatly in design and quality of manufacture. Most are simple design that do not take into consideration efficient air flows and many do not even meet OSHA or equivalent standards in safety. Many of these blow guns in the market also do not offer ergonomic design. Obviously these lower quality units are sold primarily on price. For the ones that are well designed, they may be higher in cost but will last much longer and is more comfortable to use.
For this higher quality range Nex Flow has the Easy Grip and Easy Grip Light Air Gun range to offer.
For more heavy duty applications, where more powerful energy is required, a much larger capacity air gun is required. For this reason, Nex Flow developed the Heavy DutySafety Air Gun. It is one of the few compressed air operated blow guns on the market with a ½” outlet connection. The gun is specially designed for those applications where traditional air guns are just not adequate in rugged industrial environments. The gun itself is cast zinc with properly engineered internal design to handle a larger volume of compressed air flow than a traditional, smaller air gun with minimal energy loss. It has a good ergonometric design so that when you hold the gun, it remains comfortable for any blow off and cleaning application which is especially important for safety guns of this size. Even the angle of the handle is carefully placed so operators can easily aim the gun. The rugged casting is meant to ensure a long lifetime of the product even under heavy use.
But the secret of a good air gun is not just the gun itself. It is also the air nozzle used alongside the gun. Very small air guns may only have a tapered outlet ignoring the OSHA safety standards for dead end pressure. Larger standard air guns will sometimes utilize nozzles with a side hole to release some pressure to keep the air outlet under the dead end pressure levels specified by OSHA. However, these designs are not efficient for saving energy and can also still be quite noisy. It is far better to use an engineered nozzle which primarily uses the “Coanda Effect” to convert pressure normally lost as pressure drop and noise into a high flow, high velocity and high kinetic energy output. This is what is used on all Nex Flow air guns. For the Nex Flow X-Stream Heavy Duty Safety Air Gun, the air nozzles used is either the powerful patented Nex Flow Model 47006AMF cast zinc air nozzle or the Model 47006AMFS stainless steel ½” air nozzle. These units are of course also available for use as standalone for production blow off and cleaning applications as well. Nex Flow’s nozzles are very powerful and yet safe and energy efficient. Most High capacity air guns comes with up to 3/8” outlets, but very few offer outlets of up to ½”. This larger outlet combined with internal and external designs makes the Nex Flow X-Stream Heavy Duty Safety Air Gun the most powerful with highest flow available. The Heavy Duty gun comes with a composite rubber grip and tailored handle to provide an optimal grip for the user. The force created is 5 to 7 times more than traditional air guns.
There are sometimes hard to reach areas where the Nex Flow “Heavy Duty”Safety Air Gun may be too short. In these situations, Nex Flow has three different extensions available depending on the reach one needs: 6” long, 500 mm and 1000 mm long. They are manufactured of light-weight anodized aluminum. The 500 and 1000 mm long extensions have a quality rubber grip along its length to be able to comfortably support the extension and the nozzle which would be placed at the end of the extension. This allows for the air gun to be used to get into hard to reach areas. For more flexibility, you can insert a swivel in between the extension and the air nozzle. The swivel can be locked into place at the desired angle. This feature combined with the power of the air gun size and safety nozzle makes it extremely flexible to address many different and even difficult to reach applications including cleaning.
Industries that require the Nex Flow X-Stream Heavy Duty Safety Air Gun, are heavy industries such as steel, casting, and pulp and paper plants. While other competitive models (of which there are very few), tend to be costly, our well-designed Heavy Duty Air Gun is relatively low cost yet, efficient and easy to handle.
Compressed air is safe, reliable, and used in packaging products. The compressed air systems move materials from one area of the factory to another, perform blow-off, part drying, and align products for packaging. Bakeries use compressed air for blow-off applications, while others use compressed air to clean containers before filling them with products. Compressed air technology is also used to cut, sort, shape, and convey products, such as food, from one location to another in a factory.
Cartons are also formed, filled, and sealed using compressed air. The quality of compressed air can vary widely depending on its application. The food industry requires the highest level of safe, clean compressed air to handle and package goods. Pharmaceutical industries also require more stringent clean air than other industrial applications because they are either ingested or injected.
Clean, high-quality compressed air is required in pharmaceutical and food packaging to ensure consumer safety and prevent product contamination. It is essential to have either no contact with the product or contact using pure air to avoid product recalls, damage to brand reputation, or litigation. Pneumatic systems are recommended because there is no chance of leaking oil as in hydraulic systems.
Pneumatic systems do not pollute or release contaminants into the atmosphere, so they are especially useful for packaging food products. These systems have no moving parts, so there is less maintenance and downtime compared to other systems.
Using Compressed Air in Packaging
Clean compressed air is essential for food and pharmaceutical processing and packaging operations. Compressed air must be purified, especially when the product is consumed. Compressed air conveyors are the best technology to ensure safe food quality. Contaminants include spores, solid particulate, vapors, and moisture. Oil is often not an issue with compressed air conveying systems, unlike hydraulic systems, which use oil as a medium.
To stop microorganisms and fungi growth, the dew points of air at line pressure must be -25 degrees Celsius (-15 degrees Fahrenheit). Standards have been developed that state very fine filtrations to prevent particulate and oil from contaminating food products.
How does Compressed Air Keep Products Dry and Free of Contaminants?
Equipment performance is only as good as the quality of air. Any atmospheric air contains some moisture and dirt. No matter how small the contaminants are initially, they are concentrated when the air is compressed as the air heats, its ability to hold water vapor increases. The vapor condenses into liquid when the air begins to cool as it travels downstream. Maintenance by plant operators can remove liquid, particles, and contaminants. Air dryers are installed to reduce moisture.
They lower the dewpoint of the compressed air to prevent water droplets from forming downstream. There are four types of dryers: Refrigerated, chemical, regenerative, and membrane or mechanical. Mechanical filters work with compressed air dryers to remove contaminants and water. There are three types of filters: Particulate, coalescing, and adsorption.
After the appropriate filter has been added to the conveying system to ensure that the compressed air equipment does not introduce contaminants, equipment that is used to blow off products before packaging is added, examples of this type of equipment include engineered nozzles and air knives. They conserve compressed air by using the Coandă effect to entrain surrounding air along with compressed air to create a high-flow velocity stream of air.
What are some things to remember when using Compressed Air Products for packaging?
If used as intended, compressed air will not generate biological, chemical, or physical hazards while packaging goods. The manufacturer is responsible for producing final products that are sanitized and free of contaminants such as oil, microorganisms, particulate or dust. Manufacturers that use the compressed-air system must carefully consider productivity and production costs against safety.
Compressed air used in packaging will often come into contact with the product. “Contact Application” is defined in the British Compressed Air Society (BCAS)/ British Retail Consortium (BRC) code of Practice for Food Grade Air code as “the process where compressed air is used as part of the production and processing including packaging and transportation of safe food production.” This means that packaging and moving products with compressed air is a contact application.
Other examples of compressed air contacting the product include blowing off the water after washing a product and before packaging, cooling a product to increase line speed, and blowing off excess ingredients (such as sugar) before cooking. Non-Contact Application is “the process where compressed air is exhausted into the local atmosphere of the food preparation, production, processing, packaging or storage.” Non-contact applications can be categorized into 2 additional sub-categories (high risk and low risk).
Using Compressed Air in Packaging
When designing a compressed air system for conveying, it is important to use filters and air purifiers to ensure compliance with various safety and manufacturing standards. The BCAS/BRC Code of practice recommends testing the machinery installation twice a year for contaminants such as microorganisms, particles (dirt and dust), humidity, and oil contamination. Refer to this article to learn more about the requirements in the food industry or the standards in the pharmaceutical industry.
With regards to filtration, a centralized air drying and filtration system should suffice if the pipes are relatively new in the facility. However – if the pipes are polluted or hard to clean – it is better to have both a centralized filter as well as a decentralized filter installed upstream of the point of use. New or cleaned pipes are also recommended of zinc-plated steel for food applications, V2A/V4A, compressed air-approved plastic, or aluminum.
How does it work?
The Packaging industry includes a wide variety of materials and products since almost every manufactured product is packaged: toys, food, soft drinks, beverages, cigarettes, cosmetics, brushes, kitchen accessories and more. All the products move down the assembly line before packaging. The packaging process consists of transportation lines made of pipes or ducts to carry a mixture of products and materials along a stream of air.
The pneumatic conveyor system consists of interconnected transition lines, hoses, cylinders, a gas compressor, standard cylinders, and gas (atmosphere). The compressor generates the air flow and transmits the material through a series of hoses. Manual or automatic solenoid valves control the air flow—a centrally located and electrically powered compressor powers cylinders, air motors, and other pneumatic devices. Pneumatic systems are controlled by a simple ON/OFF switch.
There are three conveyor systems that generate high-velocity air streams: a suction system/vacuum system, a pressure system, and a combined system.
A suction or vacuum is used to move light-free-flowing materials. The system operates at 0.5 atm below atmospheric pressure.
A positive pressure compressed air conveying system is used to push material from one point to another. This type of conveyor operates at a pressure of 6 atm or more.
The combined suction/pressure conveying system is used to convey material from several loading points (suction) to deliver to several unloading destinations (push).
What are some Nex Flow products applied to packaging items?
Pneumatic systems are highly recommended when manufacturing, moving or packaging any product that will be digested or inserted in a living organism, such as food or pharmaceutical goods, since there is no chance of contamination due to burst pipes or oil leaks. Nex Flow manufactures compressed air products that help companies to package goods by supplying machines used for industrial cooling (Vortex tubes), part cleaning, drying, and blow-off, and air-operated conveying before packaging.
Nex Flow engineered air optimization design improves safety while increasing manufacturing and packaging productivity and decreasing energy costs. The air-operated conveyor systems sold by Nex Flow can replace traditional conveyor belt systems, which have higher operational costs because they need to be regularly maintained.
Spot Cooling
Nex Flow pneumatic products provide the best spot cooling and blow-off solutions for materials before packaging. Vortex tubes convert compressed air into very cold air for spot cooling for industrial applications. Small vortex tube-operated mini-coolers and vortex cooling can provide extremely cold temperatures for spot cooling before packaging without refrigerants, such as CFCs or HCFCs. Vortex tubes improve factory safety and reduce noise for workers in a manufacturing environment.
Blow-Off Products
Effective, engineered blow-off products manufactured and sold by Nex flow include air knives, air amplifiers, air jets, and air nozzles. These products are another example of how Nex Flow strives to improve the safety of manufacturing and factory environments because they meet OSHA noise and pressure specifications. Among many other applications, air amplifiers are used to clean and dry parts and remove chips and part ejection.
Air knives and nozzles are used to flip open and close the tops of boxes during packaging. Air blade ionizers effectively remove static that could trap the dirt while using plastic wrap for packages.
Conveying Systems
Compressed air-operated conveying systems move materials and products at high speeds over long distances. Ring Vac Operated conveyors, and X-Stream Hand Vac are used for conveying materials where vacuum force is required to move products over long distances at high rates. Ring Vac Air operated conveyors were originally designed to help with bending and lifting goods. The speed of conveyors depends on the density of the materials (lbs./cubic foot), horizontal distance, and vertical lift.
A Ring Vac operated conveyor is a simple, low-cost solution to other pneumatic conveying systems. They are available in several materials depending on the application. Ring Vac operated systems are made of anodized aluminum or stainless steel. 316L Stainless Steel pneumatic conveyors are used when moving food and pharmaceutical products or packaging. It is available in regular and high-temperature stainless steel for high-temperature and corrosive environments.
The X-stream® Supreme Pneumatic Conveying System (XSPC) is an air-operated conveyor that uses compressed air for an efficient and power venturi action along the length of the non-clogging design. The compressed air system is designed to transport or vent lightweight items and raw materials for packaging at high rates over long distances.
The cost-effective systems are ideal for continuous or intermittent use since they are operated by a simple on/off switch and are controlled by a regulator. All Nex Flow conveyor systems are simple, easy to install and use, compact, portable, and maintenance-free.
Other benefits of compressed air-operated conveying systems are also reliable since there are no moving parts and low maintenance costs. These systems have no angles to collect contaminants such as moisture, particulate debris, or microbiological growth. They are safe for any factory environment because the system is powered by compressed air and not electricity.
Mufflers, filters, mounting systems, and static control for blowing off dust and debris from statically charged surfaces are available through Nex Flow to improve factory production and efficiency in assembly and packaging goods.
Trust Nex Flow to provide the most efficient, reliable, maintenance-free compressed air solutions for packaging your goods so that they are clean and safe for your customers.
Using Compressed Air in Packaging FEATURED PRODUCTS
Our ability to hear is critical for much of our communication yet we don’t realize it until we lose or damage our ability to “hear”.
High levels of noise can lead to permanent hearing damage and high vibration caused by noise can lead to a variety of significant medical conditions
At lower levels, both noise and vibration can cause interference with our ability to hear and feel, such as reducing the ease of normal conversation and can be annoying, irritating and unpleasant
For both noise and vibration there is generally a level below which no adverse reaction occurs
There are also favorable responses to noise and vibration
Individual responses to noise can vary significantly but there are consistent trends between noise level, measured in dB(A), and annoyance for the general public.
Nex Flow® manufactures compressed air operated nozzles, air knives and other blow off products with the above in mind. The technology works by converting energy normally lost as pressure drop into useful blowing and cooling energy with noise reduction a by-product. This by-product is very important as these noise level reductions can be 10 dBA or more.
Many production facilities put a heavy emphasis on the energy reduction from the technology but often fail to consider the importance of noise reduction.
Compressed air is just not a topic that is taught well in schools. There are organizations such as the Compressed Air and Gas Institute that offer basic courses in compressed air but the topic is just not as thoroughly understood anywhere. One of Nex Flow’s missions is to educate the marketplace about our unique technologies so you can choose the highest quality products for your needs at a fair price. With the knowledge not generally known by the public – there are biases everywhere with facts both accidentally and deliberately distorted to promote certain type of products. One such example is the promotion of variable drive air compressors where they are sometimes not the best solution. Another such example is with air amplifiers that sometimes claim to have very high “air flow amplification” with high velocity – when in fact the aerodynamic design of the amplifier loses velocity as you increase flow rate. There are a lot of air nozzles on the market that are air amplifiers as well but they are NOT the same. In this article – we will discuss 3 types of compressed air nozzles and how to boost machine efficiency by utilizing the right type of technology and to recognize what to look for when having to choose an air nozzle.
There are essentially three types of air nozzles:
Very inexpensive non-engineered air nozzles
More costly engineered cone-shaped nozzles
Even more costly engineered bullet shaped nozzles
The simple non-engineered nozzles are usually cone shaped but without taking aerodynamics into serious consideration. The outer shape may offer some energy savings – but the inside of the air nozzle also matters. A common air nozzle used in blow guns is where a cone-shaped or even bullet shaped nozzle is used on air guns and a hole is drilled on the side to let out some air so the system meets the OSHA dead end pressure safety standards. These non-engineered nozzles do not really take into consideration noise level and energy requirement.
The first real engineered nozzles were cone shaped and all are basically where compressed air exits at the base of the cone from a complete ring around the cone. They are a little more costly to manufacture but still relatively low in cost. Yet, even with these designs the noise levels and efficiency can vary extensively. Most of the engineering takes place on the outside but not always on the inside where internal compressed air movement should also be considered to minimize turbulence, pressure losses, etc. which are all determined by internal design. Two cone-shaped nozzles may look exactly the same on the outside but perform radically different because the inside is not the same. A well designed cone-shaped nozzle like the Nex Flow 47000 series takes into consideration the inside and outside aerodynamic to make the nozzle most effective while reducing noise levels and achieving energy savings compared to open tube for blow off applications. These designs normally produce a moderate force level but very high flow and this mass flow makes them ideal for liquid blow off, light cleaning and especially for cooling because of the high “amplified” air flow. One nice characteristic of a well-designed cone-shaped air nozzle is that they are effective at some distance from the nozzle due to the laminar flow produced.
Finally comes the bullet shaped nozzles which takes engineered design to another level. In this type of nozzle, the compressed air comes out of a series of small holes strategically placed around the bullet shape (as opposed to the base of the cone). Air flow inside the bullet nozzle is also designed to minimize turbulence. The placement of the holes for the compressed air to exit around the outside can control the flow profile of the nozzle. You can make the profile narrow and pointed or wider. The wider you make the profile, the weaker the point force will be (but you will get a greater area for blow off). The sharper the profile, the higher the force. This design allows for a wide variety of nozzle ranges, even for a given size to address many applications not possible with the cone shaped nozzles. In addition this design can produce a higher force/unit air consumption making them more efficient for use where force is more important than flow. The previous cone-shaped designs are better for cooling but the bullet shaped designs are better for cleaning. Typical energy savings are also higher and in the 40% range for cleaning applications. Again, as with all nozzles interior consideration is key to minimize turbulence which maximizes performance and minimizes energy and noise levels. When properly designed – these nozzles also provide great laminar flow, so they can work at a distance from the target. Nex Flow has a patented design for example in their hole design to allow their bullet shaped Air Mag nozzles to work father from the target than any other nozzles on the market. This can be a big advantage in some manufacturing operations.
One version of this type of engineered nozzle uses the so-called Laval effect which is an internal flow profile where the compressed air pushes through an hour-glass shape inside the nozzle accelerating the air at the exit creating a higher force. However, the air exit and spreads very quickly so these designs use slotted air flows in a rather inefficient manner to squeeze in the spreading air flow. The result is that the force might be acceptable while very close to the nozzle but as you move away they become much less effective.
In general both properly engineered cone-shaped nozzles and bullet shaped nozzles are effective when the flow produced is laminar and are dramatically more energy efficient than non-engineered nozzles, with lower noise levels and can work at a much greater distance.
Galvanic Corrosion – What it is and how to prevent it?
Galvanic corrosion (also called bimetallic corrosion) is an electrochemical process in which one metal corrodes preferentially when it is in electrical contact with another, in the presence of an electrolyte. This occurs in batteries for example where the cathode stays whole and the anode corrodes as the battery is working. Contrary to some believes – Galvanic corrosion does not only occur in water. Galvanic cells can form in any electrolyte, including moist air or soil, and in chemical environments. As an example, Over 200 years ago, the British naval frigate Alarm lost its copper sheeting due to the rapid corrosion of the iron nails used to fasten copper to the hull. The electrolyte in this case was salt water creating a galvanic cell.
In the case of the Alarm, the iron acted as an anode and was corroded at the expense of the copper which acted as the cathode. Just two years after attaching the copper sheets, the iron nails that were used to hold the copper to the ship’s underside were already severely corroded, causing the copper sheets to fall off.
Metals and metal alloys all possess different electrode potentials. Electrode potentials are a relative measure of a metal’s tendency to become active in a given electrolyte. When in the same environment, the more active a metal is likely it is to form positively charged electrode (anode) and the less active metal is more likely it is to form a cathode (negatively charged electrode).
The electrolyte acts as a conduit for ion migration, moving metal ions from the anode to the cathode. The anode metal, as a result, corrodes more quickly than it otherwise would, while the cathode metal corrodes more slowly and, in some cases, may not corrode at all.
The Nex Flow Difference Allowing Products to Last Longer than Competitors
While products such as air knives, air nozzles, air amplifiers, vortex tubes, etc. are not necessarily immersed in any electrolyte, if the environment is humid, or if the equipment is subject to wash down procedures, it is very possible that this type of corrosion can occur. One example is mixing stainless steel and aluminum. There was one example where a competitive cabinet enclosure cooler was observed with a big hole on its side after some years of use. The stainless steel vortex tube inside combined with the aluminum housing, and the factory environment, over time caused the aluminum to act as an anode and started to corrode.
Nex Flow® takes certain steps and actions to prevent this from happening in their products allowing the products to last longer. The first is to protect aluminum that is used, especially if combining it with steel or stainless steel. Our aluminum air knives for example – are anodized and as such have a protective coating to prevent an “electrical circuit” with the stainless steel shims used inside and the stainless steel screws used to hold the air knife together. In addition, the aluminum would tend to act as an anode anyway in an electrolytic environment and being so large compared to the stainless steel shim corrosion would be minimized. Regardless of whether galvanic corrosion would occur, the anodization also protects the air knife from any environment which bare aluminum is unprotected. Similarly, Nex Flow anodizes all their aluminum parts – air knives, air jets, nozzles, air wipes and air operated conveyors such as the Ring vacs. Air amplifiers and flat jet nozzles which are aluminum zinc-cast are powder coated for longer life and also look better.
When it comes to vortex tube technology, such as cabinet enclosure coolers (panel coolers) and tool coolers, no aluminum is used. It is stainless steel with some brass internal parts. This works to ensure that you will not find any holes in Nex Flow Panel Coolers caused by galvanic corrosion ever. So when shopping for products to blow off, clean, move, and cool, look not only at the performance data, design and workmanship – all which are important of course – but also refer to the quality and type of material used in construction. You can also refer to this article on how to avoid galvanic corrosion. Remember that materials used and how they are put together does make a difference.
Air Amplification Explained compressed air-operated amplifiers presume to reduce compressed air use and lower noise levels in blow-off and cooling applications. The term air amplifier is normally applied to annular-shaped units (called Air Amplifiers or Air Movers). However, the same technology used applies to air nozzles, air jets (which are essentially small Air Amplifiers), air knives (linear amplifiers), and some air wipe designs.
They work using the Coanda effect, which essentially is an effect in which a fluid (liquid or gas) clings to a surface as it flows in a laminar flow. You can see this effect by turning on the water tap in your kitchen at a low level, so the water flow is smooth. Put your finger just touching the flow, and it will bend the water flow as it slings to your finger. The same thing occurs with a compressed gas like air.
To achieve the best use of this Coanda effect other factors need to be considered such as the volume of the chamber that the compressed air exits to minimize any turbulence inside the chamber and minimize pressure losses. The number of and actual angles of these Coanda “angles” combined with internal designs where the compressed air is collected before exit determines the overall efficiency and performance of the compressed air used for blow-off.
As this air bends, it creates a vacuum behind it drawing in surrounding atmospheric air. This “converts” the pressure that is normally lost as pressure drops and noise into the flow. This is important. Several things occur as this additional mass flow is drawn in and mixed with the compressed air.
First, the overall force goes down because you mix with still (non-moving) atmospheric air. Secondly, the flow is dramatically increased because of this pressure conversion to flow. It is “converted energy” instead of “lost energy.” While the overall force goes down, overall kinetic energy remains high and laminar for some distance.
This means that whatever blow-off energy is required, it can perform that operation at a greater distance from the exit of the air than if compared to an open pipe or tube. And, of course, because lost energy is recovered, the noise levels drop. So when we state that air amplification is free, it is quite true, but with the caveat that overall force will be lower, but velocity and flow will both be much higher, all due to the extended laminar flow.
If air is blown with just an open pipe or tube, the exit creates a great deal of turbulence resulting in energy loss and high noise levels. This means that the force may be quite high near the exit, but it will dissipate quickly as you move away from the air exit.
There are some situations where high pressure is required. In those situations, an air amplification nozzle or device may not meet that force, such as removing heavy mud baked onto a surface or breaking off scale waste from metal. But the pipe used has to be close to the surface. However, except for those situations, air amplification technology certainly can be used instead, as the vast majority of applications where compressed air is used do not need the full high-pressure force of an airline.
One suggestion to reduce energy and noise is simply to reduce air pressure for blow-off and even cooling applications. After all, a 20% reduction in compressed air pressure will reduce the compressed air energy by 10%. If you reduce the pressure to 30 pounds from 80 pounds per square inch, that would yield a 25% reduction in energy. Noise will go down somewhat, but you will still have a great deal of turbulence at the air exit, and you will not get the “distance” for effectiveness that you would with an air amplifier.
But, even an air amplifying air nozzle will get anywhere from 30% to 40% or more energy reduction with the equivalent force, depending on the design of the air nozzle. For example, older cone-shaped air nozzle designs will reduce energy by 30% and create very high flow and velocity, which is especially ideal for cooling applications. The Nex Flow Air mag design reduces energy by over 40% and works with a powerful force and high flow, and high velocity with the laminar flow at a very long distance, as well as noise reduction.
The argument for that extra “free” energy from air amplification is therefore very compelling.
As was hinted at above, it is not just the flow profile and Coanda “angles” which affect performance. It is the internal design of an air amplifier and how the compressed air behaves internally that is also important. Minimizing internal turbulence is a major consideration in design. For example, you can take five different cone-shaped air nozzles from different manufacturers, test them side by side, and their performance and efficiency can vary by a wide margin.
In this case, efficiency can be defined as the force produced at a set distance divided by air consumption. There is a design called a Laval nozzle, for example, that was developed to produce less noise and improve energy. However, the noise level improvement is not significantly noticed due to the noise frequencies obtained, and the distance of effectiveness appears to be limited because, to make this design work, the efficient exit of the force-producing airflow has to be contained by a rather inefficient series of air flows from slots around the Laval opening, offsetting any other improvements.
The Coanda design combined with proper internal design appears to be the optimum methodology in air amplifier design.
Air jets are another example where the Coanda design makes a big difference. Air Movers or large annual Air Amplifiers, if very small, are called Air Jets. Most manufacturers of Air Jets have one Coanda angle to direct the air exiting the annual plenum. Nex Flow Air Jets have several specially designed Coanda angles and can produce the same high level of force and flow with 25% less energy and lower noise levels.
Large annual Air Amplifiers also have efficiency variations among different manufacturers because of internal and external design differences. A somewhat abused term that often comes up with annular Air Amplifiers is “amplification ratio”. One should be very wary of, frankly, ridiculous claims of high amplification ratios. For example, for annular air amplifiers, the maximum practical ratio you can achieve is about 20 to 1.
This means that if you measure the flow at the exit of an annular Air Amplifier, the flow rate would be 20 times the inlet air. For several reasons, some producers are claiming as much as 25 times, which is dubious. One reason is that when surrounding air is entrained with the moving compressed air exiting the opening in the Air Amplifier, “still” outside air will slow down the flow velocity at the outlet.
If you entrain, for example, 25 times the compressed air consumed, the velocity would be 20% less than it would be if the figure were only 20 times. That is significant because you need adequate velocity for both blow-off and cooling. Secondly, the explanations one can read on how this extra air amplification occurs should be challenged as defying physics.
In comparison, Nex Flow has done with such products, the results were a lower air amplification and even lower overall performance because of internal design and extra pressure losses internal to those systems. Anyone can always compare a Nex Flow Air Amplifier to another and see the difference. Nex Flow fixed Air Amplifiers, for example, claim 16 times amplification with a compressed air supply at 80 PSIG (5.5 bar) pressure and at standard atmospheric conditions.
These figures are averages because air amplification will go up (as much as 20) at lower inlet air pressure and if the atmospheric air is warm.
Air knives are another area where figures need to be considered between manufacturers. Air knives are linear air amplifiers. There are two styles of compressed air-operated air knives on the market. The older style uses several Coanda angles where the air exits a gap, normally maintained using a shim to set the gap, and is bent 90 degrees.
This gives a decent air amplification ratio of about 10:1 right at the exit and 25:1 to 30:1 measured 6 inches away (due to downstream air entrainment) depending on internal design effects. Some manufacturers have air knives with two gaps and claim as much of a 50:1 amplification ratio (two gaps, so they double the ratio) which makes dubious sense. You don’t double the air out and the ratio – it does not make sense to have it “additive.”
So again, it is good to challenge claims that may seem to make sense. Another thing to consider, especially with air knives, is real efficiency. Efficiency, as before, is the force measured at a distance per unit of air consumption, for example, force/SCFM. Internal design can make a difference. Newer style air knives have the airflow exiting straight out of the gap with air entrainment from special angles on each side of the air gap.
This design will provide 25% more force/SCFM than the older style versions, where the air bends 90 degrees. Hence their popularity has largely displaced the older style, but there are still some applications where the old style is useful. But even among the new style, design differences can affect performance and efficiency.
Nex Flow, for example, with their Silent X-Stream Air Blade air knife has a different internal design than two other significant air knife manufacturers and has about the same force/SCFM as them at a given pressure except for one thing… Nex Flow produces the same SCFM and same force at 60 PSIG, while the other units get equal performance and efficiency at 80 PSIG. That means a Nex Flow air knife needs less pressure to do the same job as the others.
It was quite humorous when one manufacturer claimed in a blog that our air knives used so much more air at a given pressure, but without mentioning the force produced, a poorly written defense of the fact that they are less efficient.
If the Nex Flow unit replaced the competitive unit, the air pressure could be reduced by 20 PSIG. As mentioned earlier in this article, that pressure reduction represents a 10% energy saving. So when comparing products, it is very important to look at all the facts. One of the other aspects of the Nex Flow Silent X-stream Air Blade air knife that dramatically illustrates efficiency is how quiet it is, even compared to other designs of its type.
One other point to mention is the flow profile. When an air nozzle, air jet, air amplifier, or air knife produces the amplified airflow, the profile will affect the force per square inch or square millimeter. This is particularly important in air nozzles. You need to decide on the minimum force required and the surface area you need to address.
This is especially important if putting together a row of nozzles for blow-off. You want the flow profiles to cover the required area without missing any spots or overlapping. A wider profile produces less force per unit area than a more focused air nozzle.
Air amplification is free, but among different designs, it can be more or less free than others. Besides reducing energy and noise, it is important to remember that air-amplifying products work at a greater distance than just open pipe or tubing.
The velocity produced by air amplification products is very important when used for cooling. The high velocity combined with the high flow is important, but they are mutually dependent. The more flow, the less velocity. The less velocity, the more flow. If the velocity is too low, you will not get the same cooling effect. Think of driving a car on a hot day with the window down.
It’s the same volume of air coming in to cool you, but the velocity from driving fast helps cool you more. But most certainly, air-amplifying products reduce energy use, and noise levels and make factory operations using compressed air more environmentally friendly.
Compressed air nozzle – air saving nozzle or engineered blow off nozzles are good to have but there are so many of them. This is why many people get confused and stick to the same products they are familiar with even if there are more efficient versions out there. Worse yet, in some cases engineered nozzles are not used at all and open pipes and tube are used. The price range for nozzles also vary tremendously in the market. The problem stems from a lack of compressed air knowledge to make a proper decision. In a recent Compressed Air Best practices article, there was an example of a company that reduced compressed air cost by over half – the biggest saving was actually in replacing compressed air jets and pipes with proper engineered nozzles. This alone indicates the tremendous importance to keep compressed air costs low. Another reason to choose a well designed nozzle is noise level. The exhaust noise from compressed air from open pipe is very loud – not only uncomfortable but also very dangerous to personnel. A well designed unit can reduce this noise and meet the OSHA standards for safety (dead end pressure must be less than 30 PSIG). You get energy reduction, noise reduction and safety.
But how do you choose the best compressed air nozzle? Do you choose the cheapest? The most expensive? So many designs do look the same, at least on the outside. But, the fact is, they are NOT all the same – even if they have the same external appearance. Here is why…..
First of all there are two basic designs available – the cone shaped air nozzle which is the oldest design and a bullet shaped design that was first invented in 1989 so it is relatively new. Both designs save energy, are safe and reduce noise levels. The bullet designs focus on noise reduction but also energy reduction and high force. In comparing the two designs the main difference are as follows…
On one hand, the Bullet nozzles gives a higher force/unit air consumption. On the other hand, the Cone nozzles produce a higher flow output /unit air consumption. This would imply that for applications where force is more important such as in part ejection the tendency would be toward choosing the bullet design. As for cooling, the flow output is more important and the cone shaped designs would be the wiser choice. Bullet shaped nozzles are more expensive to manufacturer and as a result are more costly to purchase.
Having said that, in either design, the performance can still vary quite dramatically. For example, we have one customer who tested a wide range of cone nozzles as for the particular application the main criteria was mass flow and not force. In this case both efficiency and noise were still important as was cost since the customer is an OEM and purchases a large volume. The Nex Flow® unit was the most quiet and the most efficient in both output and energy use. This was despite the fact that all the nozzles tested looked quite similar emphasizing the fact that “it’s not just the outside, but it’s the inside that matters”.
The same applies to the bullet nozzles. There are endless copies on the market, many claiming performance to be the same or nearly the same as the item(s) they copied. When Nex Flow® decided to create the Air Mag® nozzles a decision was made to make sure they produced the highest force/unit air consumption (SCFM) against all other brands on the market. So at least at this point in time, our Air Mag® nozzle is the most efficient bullet shaped design in the market. The other goal was to price the units lower than competitive unit with the near, or close performance as the Nex Flow® designs. Noise levels also had to match or be quieter than other models of the same size. These goal were all achieved giving birth to the first Air Mag® Air Nozzle of the series (Model 47004AMF). Price and noise level is important and an immediate means for customers to evaluate the quality. Exceeding or at least matching the performance of any competitive nozzle is important in order to easily replace less performing and/or inefficient nozzles and improve upon the application or match the previous application.
This is because “differences” are far more visible to pressure drop than other products such as air knives and amplifiers when one is replaced with another. If a competitive unit uses even as little as one additional SCFM to produce the same force, that extra flow can affect the actual pressure entering the nozzle reducing the force and not working as well. We know of one specific instance where a competitor tried to replace one brand with another that was lower in price. While similar in design, the performance did not match up despite claims of equal force in their literature. What was ignored was the air consumption so the replacement did not work. The Nex Flow® Air Mag® nozzles however would work because of its improved efficiency. This rather sensitive reaction of nozzles to installations from pressure drop tends to be the reason why companies usually opt to stay with the same brand once a decision on the product is made as maintaining consistency in output is important in production. The Nex Flow® approach allows for customers to easily test and be rest assured that they can replace possibly more costly brands with the lower cost Nex Flow® nozzle with no risk to the production operation.
Additional advantages in the Air Mag® design is more rugged for greater safety and longer life, patented hole design to improve efficiency as well as a sleek body design to keep exhaust noise levels low and allow for the unit to work effectively at a greater distance than other products on the market. This extra distance can be very important in applications where the nozzle cannot be placed close to a part.
Efficiency in force per unit of air consumption, rugged design, longer distance for effective operation, right pricing, low noise levels and safety are all good reasons to consider the Nex Flow® Air Mag® Air Nozzle.
In the previous blog,we focused on tips to prolong the life of your compressed air accessories. Today we will discuss the importance of establishing an inspection routine for your entire compressed air system along with a checklist of items to inspect.
Benefits of Regular Inspections
There are significant returns on the time you spend to inspect your compressed air system regularly. It just takes a little organization to collect detailed information and track changes. This data will encourage and direct your team to perform preventable actions to enhance your compressed air system’s performance. Other benefits of routine inspection include boosting productivity, decreasing waste, optimizing efficiency, seeing opportunities for compressed air applications, and planning for the future. This priceless information regarding efficiency and production, collected just by identifying leaks or areas of potential leaks will allow Nex Flow to recommend cost savings and increased reliability of equipment. It may also encourage your team to simply clean accessories, such as filters regularly. The knowledge of the acceptable working range of the gauges will ensure your system is running well. This knowledge can prevent major damage to equipment and prevent costly repair. It will also prolong the life of your equipment. Simply put, regular inspections will allow your compressed air system to go further, do more, and be more valuable.
Before the Inspection
It is handy to record the equipment data on a tracking sheet before you begin your inspection. Search through your files and write down the type of compressor, and manufacturer, the model and serial numbers, and flow rating Cubic Feet per Minute (CFM). Other useful compressor information includes the horsepower at revolutions per minute (HP@RPM) and pressure rating pounds per square inch gauge (PSIG). Determine if the compressor is equipped with a pressure gauge or spring-loaded safety valve. Some compressors have a drain valve while others allow you to remove water and oil.
Know the dryer manufacturer, exit flow rate at the dew point (oC or oF), and model and serial numbers. Record the oil/water separator manufacturer, model and serial numbers, and the flow rate in CFM. Keep these inspection sheets in a binder and refer to them often.
Inspection Equipment
To make easy your inspection, Nex Flow offers leak detecting equipment that makes your routine checks effortless. Ultrasonic leak detectors identify issues before they become costly to repair. Auto drains use solenoid valves for compressed air systems where air could be released to the factory floor.
Once the damage, leaks, or cracks are identified, it is important to assess the severity of the issue and prioritize so that you can improve the efficiency of your compressed air system in the best most cost-efficient way. There are various types of compressed air system inspections: visual, mechanical, calibration, and tests. When performing a visual or mechanical test, it is important to keep track of the condition of the equipment: good, dirty, cracked, etc. The age of equipment is important. Piping and tubing over time can build up scale and corrosion. The debris that collects may require cleaning. The following equipment may require replacement: Filter elements, parts in air tools such as O-rings, and tubing.
If the equipment is dirty – then the inspector should tell the employee responsible to clean the equipment. If the equipment is cracked or damaged, the maintenance personnel should be informed so that they can determine the return on investment for either repairing or replacing the equipment. Tracking the condition of your compressed air system is as important as conducting regular inspections.
Inspection List
“Treatment without prevention is simply unsustainable” – Bill Gates
“It is usually impossible to know when you have prevented an accident.” – Mokokoma Mokhonoana
Being proactive by inspecting your compressed air system regularly not only increases the life span of your equipment, but also your operation, maintenance, down-time, and replacement costs will decrease. Leaks divert up to 25 percent of your compressed air away from your system. Finally, it is an excellent source of information that is helpful in determining a return in investment for repairs. Assessments could include an accurate Cubic Feet per Minute (CFM) scoring for objective measurement. Single stage air compressors may reach pressures of 150 PSI. A single stage pump has higher CFM rating than a two-stage pump since every cylinder compressing air during every rotation.
Here is a list of items to inspect on a daily, weekly, and monthly basis:
Daily
The following items need to checked most often:
Listen for strange sounds
Keep everything tight: accessories, nuts, bolts, anchors, and screws
Check for leaks in the air inlet, receiver, delivery lines, coupling, filters, fittings, valves, and connectors.
Search for damage to external equipment or component parts
Quality of pipes: Pipes that are clean, dry, and free of corrosion are great indicators of good quality tubing and hoses
Wear and tear of equipment, especially piping. Check for damaged, aging, or cracks.
Check for cracks in drive belts and coolers
Aging disconnects for leaks
Oil level on airline lubricators and replace oil regularly
Compressed air enclosure temperature
Operating temperature and pressure of the entire system
Room ventilation temperature should be as cool as possible
Clear and clean drain traps
Look for decreases in:
Pressure
Dew point
Refrigerant pressure
Check lubrication in the distribution system and valves
Check air quality. It should be free of debris and dry
Power supply to air compressor is working well
Ensure that manual distribution condensate traps have not been left open
Dust and sludge corrode very quickly and increase leaking in compressed air equipment. Keep the air in the system dry and filtered to reduce maintenance. It is recommended that you check the following weekly:
Lines
Gaskets
Fittings
Valves
Clamps
Connections
Filters for dust, dirt, or sludge
Tanks
Condition of oil
Compressor
Check the coolant and refill it regularly since the coolant prevents your system from overheating and prolongs the life of your compressed air system.
Use test buttons on electronic systems and manual bypass valve to ensure that all drain traps are working correctly
Monthly
The following items should be checked monthly:
Examine your compressed air system system’s response to manufacturing requirements
Calibrate sensors, controllers, and valves
Access your factory’s true production level efficiency and determine areas of improvement
Completeness of air compressor system assembly
Equipment rotation
Equipment identification, labeling and tagging
Adequate working space for ventilation
Control system
Comparison to plans and drawings
Safety devices
Test the following for operation efficiency:
Air compressor
Air dryer
Water and oil separator (if applicable)
Pressure
Filter and traps
System test
Receiver system is stopping at the set maximum pressure
Most importantly, take notes and track your information so that you can identify trends and budget for future expenses such as repair and replacement of aging equipment. Information that is important to note includes: operating temperatures, pressure, flow, and levels.
After the Inspection
Regular inspections should be conducted by the same employee but if that is not possible track the personnel who did the inspection by recording the following information: Name, Designation, Contact Information, the Time and Date of the inspection with signature sign off. The inspection should be acknowledged by your safety liaison officer and manager. The approval of the inspection should be signed by the person responsible for inspection. Typically, the person responsible is the factory floor manager.
Nex Flow technical experts are happy to help you inspect, analyze, and recommend areas in your factory environment that could improve cost savings, reliability, and productivity.
Nex Flow compressed air accessories can complement and enhance your compressed air systems. Awareness of the best accessories (based on application) can save energy, extend the lifespan of equipment, and provide a safe environment for workers when using compressed air. This article describes tips that enhance the performance and prolongs the life of compress air accessories.
What are Examples of Compressed Air Accessories?
Compressed air accessories include filters (oil and water), separators (shims), valves, nozzles, tubing, hoses, etc. Nex Flow engineering experts are happy to provide advice when choosing the best compressed air accessories for your application. We are dedicated to reducing the cost of compressed air system operation and extending the life of your products. All products come with a 5-year manufacturing warranty.
Prevent Leaks
Benjamin Franklin once said, “An ounce of prevention is worth a pound of cure.” Be proactive by regularly checking for leaks in filters, fittings, valves, and connectors. Leaks occur especially when your compressed air system is aging. Inspecting your entire system regularly prevents leaking air. Leaks can originate from lines, gaskets, fittings, valves, clamps and connections. They can divert an estimated 25 percent of your compressed air. Leak detectors can be helpful in identifying the issues before they become costly to repair. In addition, solenoid valves can be used to control the flow of liquid and gases.
Check the quality of pipes in your compressed air system. Simply using quality and replacing worn out pipes can save energy and maintenance costs. Pipes that are free of corrosion, clean, and dry are a good indication of quality piping. If the air is not properly filtered, dust appears in the pipes which could lead to inlet filters becoming clogged, causing a decrease in pressure, and the chance of product contamination. If left unattended, wastes will accumulate, and these dust and sludge will corrode piping very quickly and exacerbate leakage. Properly dried and filtered air keeps your pipe system clean and reduces maintenance.
Inspect Equipment Regularly
Strange noises and excessive vibration are indications of problems. Learn to recognize issues as soon as problems occur. Inspect the entire compressed air system regularly including accessories. Keep everything tight because otherwise screws, nuts, and bolts can all loosen. Tighten accessory that has become loose. It is highly recommended to regularly inspect your system, understand and know the acceptable range of the gauges so you can flag if the system is abnormal. This knowledge can prevent major damage to equipment and prevent costly repair. Check the coolant and refill it regularly since the coolant prevents your system from overheating and prolongs the life of your compressed air system.
Cleaning
With the help of expert technicians with years of experience, develop a daily cleaning routine of your system and accessories. Remove filters and blow them clear of dust to extend the life of the pipes, filters, and nozzles. Dust and debris can collect in filters and if they clog, it will impact the effectiveness of your system. Other than dusts, filters should also be drained of any liquid they collect. Remember that any residue may dry and leave a film – this is especially hard to remove if it is an oil residue. So before putting the filters back in use – it is important the filters are properly drained and cleaned to prolong the lifespan of the product.
Seek out moisture in your entire system. Moisture can cause wear and tear on your accessories. Condensation can deteriorate the health of your system and shortens the lifespan of equipment. Ensure that the air compressor is eliminating moisture as expected on a daily basis. Furthermore, check drains and separators to ensure that no moisture is pooling.
Maintenance
It is highly recommended to follow the compressor maintenance schedule. Ignoring maintenance costs more because it leads to costly repair and replacement expenses. It is critically important that the correct lubricant is used on tools and compressed air accessories to promote long life. Incorrect lubricant can damage internal parts. For blow-off or air conditioning systems, it is equally important not to use a lubricant since it could block the nozzle. In situations where the entire air system is lubricated, it is recommended that an oil removal filter is installed upstream.
A compressor runs more efficiently when properly maintained. Proper compressor maintenance cuts energy costs and prevents breakdowns. Maintain oil change schedules and other timely scheduled maintenance on your compressors. Consult your air compressor supplier for advice regarding the most efficient method to run based on the application of use, especially if you own several compressor units.
Vortex tube cooling for cabinet enclosures is essential in very dirty or humid environments. The use of cabinets coolers not only keep the control panel clean but also keep maintenance costs to a minimum. If the equipment become clogged and stops working, the cost of an enclosure is easily recovered compared to stopping work to repair sensitive parts on the control panel.
Pre-packaged Electronic Thermostat
Setting the temperature of when compressed air will be used, will extend the lifespan of your equipment. Thermostats control the temperature setting inside your control panel. The compressed air equipment will only be used when necessary. Also, Nex Flow®Panel Coolers ensures a positive pressure to keep out atmospheric air in control panels. A small amount of air flowing into the control panel is important to maintain a slightly positive pressure. Nex Flow also offers a special temperature-sensitive sticker that is put on the outside of a control panel as a qualitative indicator to show when a panel is overheating.
Proper Filtration Use
Using proper filters based on the application and changing filters regularly will prolong the life of your blow off products. Instead of using cartridge filters, where water and oil removal pose a high maintenance cost, it would be wise to use the following compressed air accessories for longer life:
Oil Removal Filters – an excellent choice for oil removal because it filters up to 0.3 microns.
Liquid Super Separator – removes 99.99% oil and water from a compressed air system. This filter addresses access water problems and extends the life of existing filters.
Use Stainless Steel Shims for longer life
Unlike other manufacturers – Nex Flow® only sells stainless steel shims because we understand that plastic shims will wear out quickly. When required, shim kits and individual sizes are available for spare parts, enlarge the gaps in existing products to increase flow/force, or to replace old shims if necessary.
Conclusion
Having keen knowledge of how your compressed air system works optimally only occurs when a regular maintenance and inspecting schedule is kept. Once you are aware of your compressed air system, issues. Loose or loud components, can be quickly replaced and maintained before expensive repairs are necessary. Knowing the correct compressed air accessory for the application will save operation costs and extend the life of the equipment you have installed. Nex Flow is the company that is most qualified to help you select the most effective compressed air accessories for your application.
Have you ever heard someone said something along the lines of “well that’s definitely a powerful machine – just listen to how loud it is”. While this may be true some of the time it is not always the case. When working with compressed air, having a well-designed machines and accessory that is equally powerful at a much lower noise level is always a plus. Here are some things to consider about noise.
Loud Noise Means Less Efficiency
Have you ever tried to concentrate with loud noise? It is much more difficult to think clearly with loud noise. But it’s not just personal efficiency that can be negatively affected, the efficiency of the device making the noise can also be jeopardized. For instance, the noise involved with compressed air blow-off can mean a leakage or an inefficient design. It is still prevalent to use open tubes and jets and drilled pipe for blowing compressed air in production applications to clean, cool and move products. However, the exhaust noise using these methods can exceed 90 dBA depending on the pressure used and the bulk of the noise generated by this method of blowing with compressed air is from the energy lost as it exits the tube or pipe. In other words, the energy is loss as noise and pressure drop because the flow and force from dilled pipes and open tubes are mostly turbulent.
Turbulent Flow can be characterized as having tiny whirlpool regions and it also increases the amount of air resistance which is useful for accelerating heat conduction and thermal mixing. However, it is not useful for blowing applications. Turbulent flow will produce a great deal more noise. For blowing with compressed air, whether for cooling or cleaning or drying, laminar air flow is preferred.
Laminar Flow is when the flow of a fluid (in this case, air) follows a smooth path, or paths which never interfere with one another. One result of laminar flow is that the velocity of the fluid is constant at any point in the fluid movement path.
Just how much can noise be reduced and how much energy saved using blow off products that produce a laminar flow? The answer is – quite dramatic. A laminar flow nozzle can reduce noise levels as much as 10 dBA and reduce energy consumption by 30% – 40%. Likewise, laminar flow air knives which is basically long, flat nozzles are used to replace drilled pipe for higher efficiency. Some designs are extremely quiet and can reduce exhaust air noise to as low as 69 dBA.
High Noise Level is a Hazard
Of the roughly 40 million Americans suffering from hearing loss, 10 million can be attributed to noise-induced hearing loss (NIHL). NIHL can be caused by a one-time exposure to loud sound as well as by repeated exposure to sounds at various loudness levels over an extended period of time.
Sound pressure is measured in decibels (dB). The average person can hear sounds down to about 0 dB, the level of rustling leaves. A handful of people with very good hearing can hear sounds down to -15 dB. On the other end of the gauge, a sound that reaches 85 dB or stronger can cause permanent damage to your hearing even if exposed for a very short time. The timespan you listen to a sound affects how much damage it can cause. The quieter the sound, the longer you can listen to it safely. A very quiet sound will not cause damage even if you listen to it for a very long time. However, a sound that reaches 85 dB can cause enough damage to induce permanent hearing loss. Here are some common sounds.
A typical conversation occurs at 60 dB – not enough to cause damage.
A bulldozer that is only idling (not actively bulldozing) is loud enough at 85 dB – after only 8 hours it can cause permanent ear damage.
When listening to music – a stock earphones at maximum volume can generate sounds reaching a level of over 100 dBA. Loud enough to begin causing permanent damage after just 15 minutes a day!
A clap of thunder from a nearby storm (120 dB) or a gunshot (140-190 dB, depending on weapon), can both cause immediate damage.
It is estimated that as many as 30 million Americans are exposed to potentially harmful sounds at work. Even outside of work, many people participate in recreational activities that exposes them to harmful noise (i.e. musical concerts, use of power tools, etc.).
Designing the Future of Air Blow Off Technology
Nex Flow® Air Products Corp. continually perform and fund research to constantly improve the efficiency and safety of compressed air accessories. With this approach, we are able to offer noise reduction for compressed air technologies that are equally or more efficient than competitive units.
Air Nozzles
Our Air Nozzles are engineered to reduce noise by 10 dBA over open pipe, tube or jets and maximize laminar flow to increase force/compressed air consumed.
One of the oldest styles of air saving, noise reducing air nozzles are of a cone shaped design. But if you put every single design next to one another both energy saving and noise reduction will vary greatly because many times the aerodynamic design is neglected. Having the nozzle outside appearance as a cone shape in not enough. There are many other (proprietary) factors to consider to truly minimize turbulence and maximize laminar flow. The cone shaped designs are still the optimum style to use for maximizing total volume of flow produced per quantity of compressed air consumed and is especially ideal for cooling applications. Where cost is a factor, this model is ideal.
The Air Mag is another one of our engineered nozzle with patented design. The bullet shaped design trumps the cone shaped design for producing the highest force/quantity of compressed air consumed. The patented design allows the Air Mag to provide the furthest distance for laminar flow compared to competitive units. Other bullet shaped nozzles need to be close to the target as turbulent flow begins to occur after only a short distance from the nozzle. Our unique design helps significantly extend the range of the laminar flow. Due to increased complexity and manufacturing processes, they are more costly than the cone shaped designs. However, they are the best option for when force produced is an important factor.
Air Knives
When replacing drilled pipe with holes, the Nex Flow Silent X-stream Air Blade air knife lives up to its name. At 80 PSIG the unit is runs on just 69 dBA exhaust noise and uses the same air consumption as if running competitive units at 60PSIG. Extremely popular as they often replace competitive units in the field because of the design and quality of manufacture.
Other blow off products we offer include air flow amplifiers, air jets, and many more. Our accessories are used not only for blow off and cooling applications but can also be used for conveying, cleaning and to control static electricity.
The next time you hear a loud sound when using compressed air anywhere in the production line, don’t forget to check and see what is making that noise. Loud noise is a health hazard and is often wasted energy. So, if the source of the noise is coming from an open tube, open pipe or a drilled pipe of any sort, chances are, you can reduce this noise very quickly and even reduce energy and get better performance by using low cost products from Nex Flow®.
Recommended compressed air standards and related terms
There are several major standards to consider with the use of compressed air – two with regard to air quality, one for compressed air safety and any local standards related to noise.
Since compressed air is used in so many areas where it can come in contact with food or medicines, air quality standard is probably the most important standard related to compressed air use. ISO 8573, established in 1991 is a multi-part standard for compressed air quality to facilitate compressed air system component selection, design and measurement. Part 1 classifies contaminant type and assigning air quality levels, and Parts 2 through 9, define testing methods to accurately measure a full range of contaminants within the end user’s facility. The ISO 8573 Air Quality standard does not however address how manufacturers are to test and rate the filters. The ISO 12500 filter standard was developed to address this issue and establishes how manufacturers test and rate compressed air filters by defining critical performance parameters (namely, inlet oil challenge, inlet compressed air temperature and pressure measurement techniques) that will deliver certifiable filter performance information suitable for comparative purposes.
ISO 12500 is a multi-part standard, with ISO 12500-1 encompassing the testing of coalescing filters for oil aerosol removal performance, ISO 12500-2 quantifies vapor removal capacity of adsorption filters, and; ISO 12500-3 outlines requirements to test particulate filters for solid contaminant removal.
Occupational Safety and Health Administration (OSHA) standard 1910.242(b) requires that compressed air used for cleaning purposes must be reduced to less than 30 psig (pounds per square inch gauge, 204 kPa). Compressed air used for cleaning must only be permitted with effective chip guarding and personal protective equipment to protect the operator and other employees from the hazards of the release of compressed air and flying debris. Standard 1917.154, which addresses similar hazards in the maritime industry, explicitly prohibits the use of compressed air for personnel cleaning. While this particular requirement is not specifically applicable in the general industry setting, it is recognized as good practice for all industries. Standard CFR 1910.242(b) is a major guideline for Nex FlowTM in the design of their air saving nozzles, to keep dead end pressure under 30 psig.
Noise standards vary around the world. Compressed air, when exhausted from cylinders, air nozzles especially, produce noise – both impact noise and exhaust noise. Please refer to our article on noise levels for more detail.
Terminology used in compressed air systems can be confusing, so we have defined some for you along with common units and conversions below (the terms do not include terms related specifically to the compressors themselves – just terms downstream).
Absolute Pressure – The measure of pressure compared to the absolute zero pressure of an empty space—e.g., a vacuum. Expressed in pounds per square inch (PSI) or bar (BAR) or kilopascals (KPa). 1 bar equals 14.7 PSI equals 100 KPa
Actual Capacity – Also known as Free Air Delivered (FAD), this is the amount of gas actually compressed and delivered (at rated speeds and conditions) to a discharge system. Expressed as cubic feet per minute (CFM) or liters (LPM) per minute where 1 CFM = 28.32 LPM.
Air Consumption – The compressed air consumed from the compressed air system by any machine, air tool or blow off device to operate expressed at a particular input pressure to the device and usually in SCFM or SLPM as defined further below.
Amplification Ratio – A term typically used with blow off devices such as engineered air nozzles, jets, air amplifiers, air knives to express the amount of increase in air flow compared to the compressed air used. Should be expressed at a particular distance from the blow off device. It is usually and average over various inlet pressures.
Atmospheric Pressure – The measured surrounding pressure of a particular location and its altitude. Measured in PSI or BAR or KPa as explained above
Blow Off Force – The force produced by a blow off nozzle, jet, air knife or amplifier on pounds force or grams as a particular pressure at the device inlet, expressed at a particular distance from the device.
Free Air CFMor LPM– Air’s flow rate at a specified point and condition, which is then converted to surrounding conditions.
Actual CFM or LPM – Air’s flow rate at a specified point and condition.
Inlet CFM or LPM – Air that is flowing through the inlet filter or valve of a compressor (under rated conditions).
Standard CFM or LPM – The flow rate of free air that is measured and then converted to a uniform set of reference conditions. Normally expressed as SCFM or SLPM.
Dew Point – The temperature point at which moisture starts to condense in the air, if the air continues to be cooled at a single pressure.
There are two types of Air Amplifiers – Air Pressure Amplifiers and Air Volume Amplifiers. This article talks about volume amplifiers, which harness the energy from a small parcel of compressed air to produce high velocity and volume, low pressure air flow as the output. It can amplify the volume up to 17 times the air consumed.
The volume amplifier uses an aerodynamic effect called “the Coandă effect”. One example of this effect is seen on the Coandăangles on airplane’s wing that can cause the airplane to lift. In an airflow amplifier, the force is directed outward to cool or dry a surface. Pressure normally lost as noise and is converted into amplified and high velocity laminar flow.
Compressed air stream flows through an air inlet, clinging to the “Coandă” profile inside. The compressed air is throttled through a small ring nozzle at high velocity and guided towards the outlet. This results in a low-pressure area at the center, inducing a high volume of surrounding air flow to the airstream. Airflow is further amplified downstream by entraining additional air from the surroundings at the exit. This adds further volume and flow to the primary airstream via a similar method. The combined flow of primary and surrounding air exhausts from the Air Amplifier is a high volume, high velocity flow.
The jets of air in the amplifierscreate a high velocity flow across the entire cross-sectional area, which pulls in large amounts surrounding air, resulting in the amplified outlet flow.
Note: Air Amplification Ratio is the ratio of the air flow in standard cubic feet/minute (SCFM) or standard liters per minute (SLPM) at the exit point divided by compressed air consumption with the same unit. This ratio can vary with inlet pressure and temperature as well as the density of the inlet air, so the figure provided is a weighted average. The ratio may be reduced if any back pressure is put on the amplifier exit or suction end by attaching a hose, pipe or tubing
There is a balanced between amplified air flow and air velocity. Any air amplification ratio higher than 17 will slow the velocity so much that the blow off force becomes ineffective and the cooling effect lost.
NOTE: It is recommended to regulate the compressed air supply so the very least amount of air necessary is used. Install a solenoid valve on the compressed air supply side to turn the air off when the air amplifier is not in service.
Air Jet
Air Jets are either annular like Air Amplifiersor in a flat design (air edger). Due to their size and “Coanda profile”, annular Air Jets provide a greater concentrated force using amplified air. This makes them ideal for applications like part ejection. Nex Flow Flat air jets or Flat Jet Nozzles are a compressed air operated chamber of shorter length than an air knife with a higher force and flow design. The internal chamber and outside shape are designed to minimize pressure drop and convert this into flow and force.
Flat Air Jet Nozzle (Air Edger®) is used when a much stronger forced air is required than an air knife can provide. The flat jet nozzle can be mounted on manifolds of different lengths (holding 2, 4, or 6 units typically and more). Like an air knife – shims can be added to produce higher force. Due to the chamber design that is quite different from an air knife – a greater range of shims can be added to the flat nozzle allowing it to produce much higher air force than an air knife is able to provide. The Air Edger® Flat Jet is available with various size “gaps” all set with a flat stainless steel shim. Three standard shim sizes are available – .004” (.10 mm), .008” (.2mm) and .020” (.51 mm). Shims can be “stacked” for a larger gap and greater force up to a maximum gap of .024” (61 mm).
Air Knife
An air knife is positive pressurized air chamber that contains a series of holes or continuous slot through which a predetermined air volume and velocity exits. The air is blasted through the air chamber using an air compressor or industrial blower. The air knife is typically made from either aluminum or stainless steel of various lengths but can be made of other materials as well.
Note: Electrical currents from anti-static bars can also be injected into the air knife air stream to neutralize the static electricity charge on some surfaces.
Things to consider when choosing an air knife includes:
Force required
Material: typically aluminum, stainless steel, and special plastics
Required Length or distance from the compressed air source to the target.
Installation Cost
Noise
Air Consumption
Applications of Amplifier, Jets and Knives
Air Amplifier
There are many different applications for air amplifiers to completely list – but main applications include blow off, cooling, and ventilation:
Blow off:
Purging tanks
Used in ventilation of fumes, smoke, lightweight materials from automobiles, welding, truck repair, plating or holding tank or other confined spaces.
Circulate and blow off air
Cool hot parts: Cooling dies and molds
Dry wet parts
Clean machined parts:
Vacuum device to clean machined parts and confined places: dust collection, remove metal chips and scrap, collect and move dust (grain operations)
Clean a conveyor belt or web
Convey:
Used to convey small parts, pellets, powders, and dust.
Exhaust tank fumes; Used to remove fumes quickly and efficiently for venting applications. The fumes can be ducted away, up to 50 feet (15.24 m), and the amount of suction and flow is easily controlled.
Moves air 12 to 20-fold in duct applications and up to 60 times in areas with no ducts.
Component removal, valve gates, and automated equipment for ejection molding systems
Distribute heat in molds/ovens
Sort objects by weight
Used as tools in production lines, wood working, aerospace, construction, dentistry, heath care and hospitals
Used in assembly, chemical processing, robotic cells, and chemical processing
Increasing existing plant air pressures
Used in medical, food, and pharmaceutical installations
Used in Pneumonic cylinders: Enhances efficiency of pneumonic tools and machinery
Bottle molding applications
To enhance the “WOW!” factor of amusement rides in certain thrill rides; such as roller coasters
Coat a surface with atomized mist of liquid
Activating adhesives and heating-shrinking: High air amplification puts much more airflow through the heater coils than would be possible with an ordinary fan or blower. The hot airstream can be felt over 10′ (3m) away!
High temperature /corrosive (up to temperature of 700 F (371 C)
1 1/4” (32 mm)
Cooling
Moving hot air for uniform heating in ovens or furnaces
Exhaust
Circulate air, move smoke, fumes, and light material
Clean and dry parts
2” (51 mm)
4” (102 mm)
Circulate air, move smoke, fumes, and light material
Clean and dry parts
Venting or cooling
Available 0.002 and 0.003” shims can be added
Gap setting from 0.001” to 0.004” to control the output flow and force required.
Material
Application
Plastic
Cooling
Moving hot air for uniform heating in ovens or furnaces
Exhaust
Circulate air, move smoke, fumes, and light material
Clean and dry parts
Aluminum
High temperature/corrosive
Stainless steel
High temperature/corrosive (up to temperature of 700 F (371 C)
Medical, food, and pharma installations
Blow off, cooling, or venting
Special plastic versions are used to cool materials in an electrical power grid where metals can not be used. Alternative materials can be machined to be used as an air amplifier unit in corrosive environments where stainless steel is not sufficient.
Nex Flow manufactures special Air Amplifiers to your specification including special flanged mounting style or with a PTFE plug to avoid sticky material build up.
Benefits to Using Air Amplifiers: For air amplifiers, the outlet flow remains balanced and minimizes wind shear, sound levels are typically three times lower than other types of air movers. Both the vacuum and discharge end of the Air amplifier can be ducted, making them ideal for drawing fresh air from another location or moving smoke and fumes away. They are ideal for increasing existing plant air volume for blowing or cooling and for venting.
Compact, lightweight, portable
No electricity
No moving parts – no maintenance
Ends are easily ducted
Instant on/off
Longer life in difficult environments than competitive models.
Lower compressed air consumption than ejectors and venturi.
Maintenance free with output easily controlled, safe to use.
Air Jet
Flat jet air nozzles are used for a concentrated and targeted application of air and other gases. They are used to provide a powerful stream of high velocity laminar flow and high force for blow off and cooling applications where air knives are not sufficient.
Annular Air Jets entrain large volumes of surrounding air through the Jet (like Air Amplifiers) and are more efficient flow amplifiers than Air Nozzles. They cover a larger blow off target than a Nozzle and are ideal for part ejection. An air nozzle provides a point force, while the Air Jet acts more like a “hand” and covers a larger area in blow off coverage. This can be an advantage in part ejection where two nozzles are normally required to “direct” the ejected part while only one jet is needed. This can dramatically reduce energy required as well as have a lower footprint on themachine.
Applications of an air jet:
Part cleaning
Chip removal
Part drying
Part ejection
Air assist
For moving heavier material that requires extra force to move.
Benefits to using an Air Jet: Air consumption and noise levels are minimized with its special design and configuration while providing a strong blow off force.
Reduced compressed air cost
10 dBA average noise reduction
Conserve compressed air
Compact
Improved safety
Meets OSHA noise level requirements
Improved production
Air Knife
An air knife is used to create an air curtain to clean, dry, or cool a surface of a product without mechanical contact. In most cases, the air knives are stationary while the products that are cleaned or cooled are traveling on conveyors. In other manufacturing applications, the air knife moves or rotates over the surface of the stationary product. In rare circumstances, an air knife can be used to cut products. One such example in the food industry is by using an air knife to cut into cake frosting.
The following is a comprehensive list of air knife applications using compressed air:
An air knife is used to blow off a curved or flat surface of unwanted liquid (such as water), grime, airborne debris, dirt, or dust from surfaces or objects using a high-intensity, uniform sheet of amplified airflow.
Air knives are a good cooling tool.
They are also used to control the thickness of liquids
Used in food, pharmaceutical, packaging, automotive, mining, heavy industries (steel and aluminum), and circuit board manufacturing, and printing
Used the first step in recycling to separate lighter particles from other components.
Used in post manufacturing of parts for drying, conveyor component cleaning, and to draw in waste fumes or exhaust.
Create an invisible air barrier to separate heated or cooled environments from one another in industrial applications such as continuous metal heat treating ovens, cold process or storage areas in food processing or dust containment for the entrance to clean rooms.
Removal of excess oils, liquids, and dust from flat and curved surfaces
Part Drying after wash
Conveyor cleaning
Component or Parts Cooling
Drying or Cleaning of Moving Webs
Environmental Separation (air barriers)
Blow off in pre-paint systems
Bag opening in filling applications
Scrap Removal in converting operations
Benefits to Using compressed air – air knife:Compressed air operated air knives are more compact in design, easier to control, and far less noisy than blower operated units.
Quiet – 69 dBA for most applications
Uniform airflow across entire length
Minimal Air Consumption
High Force/Air Consumption Ratio
Variable force and flow
No moving parts – maintenance free
Easy mounting
Compact, rugged, easy to install
Stainless steel screws in all models
Standard Units 30:1 air amplification
X-Stream Units 40:1 air amplification
X-Steam Units can do the same job as competition at lower pressures
Materials Anodized Aluminum, Hard Anodized Aluminum, 303/304 stainless steel and 316L stainless steel
Stainless Steel shim
Special Lengths Available
Blower operated systems are advertised as being more energy efficient but that is not always the case. In intermittent blowing and lower pressure applications, compressed air knives can be as energy efficient as blower operated systems.
Compressed air operated air knives have smaller/more compact dimensions, more rugged, quieter, and do not have the costly maintenance compared with blowers, making compressed air operated systems the smart choice especially when space is a premium. A compressed air operated air knife provides significantly more force than a typical blower.
Air knives are ideal for liquid and dust blow off. Air knives provide clean, heated air; low operating noise (even without sound enclosures); and easy installation and operation.
Drawbacks to Using Compressed air – Air knife: Not good for heavier material that needs to be removed. In this case, choose an air jet.
Conclusion
Compressed air operated Air Amplifiers, Jets, and Knives are effective tools for your manufacturing environment. It is critical to know the requirements of your application to choose the correct product. Experts at Nex Flow are happy to assist you in choosing your compressed air solution for your manufacturing application.
“What does dBA mean when someone talks about noise levels?”
Compressed air exhaust produces noise whether from cylinders, solenoid valves, or from blow off nozzles. Air conditioning and cooling technology has become more advanced as individual, industrial, and manufacturing demands have increased at the same rate. The efficiency of a type of cooler is a primary concern, but so is the noise level. Different types of air conditioners emit different noise levels and are noisier as they age. It is important to understand how noise is measured and the strategies that can be used to reduce noise in your factory environment. This article describes Occupational Safety and Health Administration (OSHA), their recommended occupational noise limits, penalties for not complying, and products that are designed to reduce noise so that the factory environment can comply with OSHA recommendations.
What is Noise and How is it Measured?
Most of us live and work in loud environments. Without proper ear protection, this can lead to profound hearing loss, which affects the quality of life of us, our friends, and our family. Noise and vibration are both fluctuations in the pressure of air (or other media) which affect the human body. Vibrations that are detected by the human ear are classified as sound. We use the term ‘noise’ to indicate unwanted sound.
The logarithmic scale that measures sound and loudness is called a decibel.Sound energy travels in waves and is measured in frequency and amplitude. The intensity of the noise emitted from air conditioning units, for example, is the force of the sound wave (amplitude) and is measured in decibels (‘dB’). The decibel scalestarts 0, the softest sound a human can detect, and increases in multiples of 10 dB. Every increase of 3 dB represents a doubling of sound intensity or acoustic power. Table 1 lists the common sounds that are heard:
Table 1: Common Sounds
Sound
dBA
Breathing
10
Normal Speaking Voice
65
Rock concert
120
Dog Barking from 4 feet
95
Passenger car at 65 mph at 25 ft
77
Vacuum Cleaner
70
Noise levels is measured by a sound level meter using the decibel scale. The factors affecting the reading are:
The distance between the meter and the source of the measured sound
The direction the noise is facing relative to the meter
Is it an indoor or outdoor measurement? Outdoor sound will dissipate more than indoor noise, which reverberate.
For the sound measurement to be useful, the conditions under which the reading is taken and the distance from the source must be reported.
When purchasing a new air conditioner, the decibel noise level is printed on the specifications for indoor and outdoor units. If the decibel level is not on the specification, ask the installer to provide the measurement.
What is the difference between dB and dBA?
A dB(A) measurement has been adjusted to consider the varying sensitivity of the human ear to different frequencies of sound. Therefore, low and very high frequencies are given less weight than on the standard decibel scale. Many regulatory noise limits are specified in terms of dBA, based on the belief that dBA is better correlated with the relative risk of noise-induced hearing loss.
Compared with dB, A-weighted measurements underestimate the perceived loudness, annoyance factor, and stress-inducing capability of noises with low frequency components, especially at moderate and high volumes of noise. (Richard L St Pierre Jr and Daniel J Maguire, “The Impact of A-weighting Sound Pressure Level Measurements during the Evaluation of Noise Exposure” (paper presented at NOISE-CON, Baltimore, Maryland, July 12–14, 2004).)
db-C or the C-weighting scale is sometimes used for specifying peak or impact noise levels but there is generally not much of a difference between the two.
Occupational Safety and Health Administration (OSHA) Occupational Noise Exposure
Occupational Safety and Health Administration (OSHA) is an agency of the United States Department of Labour. Congress established the agency under the Occupational Safety and Health Act, which President Richard Nixon signed on December 29th, 1970.
OSHA sets legal limits on noise exposure in the workplace. These limits are based on the time a worker spends during a weighted average over an 8-hour day. With noise, OSHA’s permissible exposure limit (PEL) is 90 dBA for all workers for an 8-hour day. The OSHA standard uses a 5-dBA exchange rate.
The potential for a sound to damage hearing is proportional to its intensity, not its loudness. That is the reason why it is misleading to rely on our subjective perception of loudness as an indication of the risk to hearing.
Noise and vibration can harm workers when they occur at high levels or continue for a long time. The greater the sound pressure a sound has, the less time it takes for damage to occur to hearing. For example, an 85-dBA sound may take up to 8 hours to cause permanent damage, while a sound at 100 dBA can damage hearing after 30 minutes. Occupational exposure limits (OELs) for various noise levels are the maximum duration of exposure permitted. Table 2 lists decibel exposure time guidelines.
Table 2: Decibel Exposure Time Guidelines with Examples
Continuous dB
Examples
Permissible Exposed Time
85
Busy City Traffic
8 hours
88
4 hours
91
2 hours
94
Gas powered mower,
Hair dryer
1 hour
97
30 minutes
100
15 minutes
103
7.5 minutes
106
Tractor (105 dB)
< 4 minutes
109
< 2 minutes
112
< 1 minute
115
Leaf Blower, Rock Concert, Chainsaw
< 30 seconds
Table 3: illustrates the comparative noise level differences by 10 decibels
Noise Source
Decibel Level
Effect
Jet take-off (at 25 meters)
150
Eardrum rupture
Aircraft carrier deck
140
Military Jet Aircraft take-off from a carrier with afterburner (50 ft)
130
Painful. 32 times as loud as 70 dB
Steel mill auto horn at 1 m; live rock music
110
Average human pain threshold. 16 times as loud as 70 dB
Power lawn mower; Bell J-2A helicopter at 100 ft
100
8 times as loud as 70 dB. Serious damage possible in 8-hour exposure.
Motorcycle at 25 ft
90
4 times as loud as 70 dB. Likely damage in 8-hour exposure.
Dishwasher; Average factory, car wash at 20 ft; food blender
80
2 times as loud as 70 dB. Possible damage in 8-hour exposure.
TV audio
70
Upper 70s are annoying to some people
Conversation in a restaurant
60
Half as loud as 70 dB.
Conversation at home
50
One fourth as loud as 70 dB.
Library
40
One eight as loud as 70 dB.
Rural area
30
One sixteenth as loud as 70 dB
Whisper
20
Breathing
10
Barely audible
American Criteria
OSHA requires that workers exposed to an average of 90 decibels for eight hours wear hearing protection. Under the agency’s measurements, when the volume increases by 5 decibels, the nose doubles. As a result, the permissible exposure time is cut in half. If the levels reach 95 decibels, the maximum exposure without hearing protection is 4 hours.
The counsel for accreditation in occupational hearing conservation (CAOHC) has stricter guidelines. “Under the stricter guidelines, workers may not be exposed to 85 decibels for more than 8 hours a day without hearing protection. Several agencies have also concluded that the risk of hearing loss doubles with every 3 decibels increase, not 5.” (The New York Times, Retrieved on October 25, 2018)
Find out more about workplace safety and health topic with NIOSH here.
Canadian Criteria
The criterion level, often abbreviated as Lc, is the steady noise level permitted for a full eight-hour work shift. This is 85 dB(A) in most jurisdictions, but it is 90 dB(A) in Quebec and 87 dB(A) for organizations that follow the Canadian federal noise regulations.
The exchange rate is the amount by which the permitted sound level may increase if the exposure time is halved. The allowed maximum exposure time is calculated by using an exchange rate. As the sound level increases above the criterion level, Lc, the allowed exposure time must be decreased.
“In 2003, Directive 2003/10/EC of the European Parliament and of the Council on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (noise) was adopted. This directive is to be transposed into the national legislation of all Member States before 15 February 2006 (132). The main characteristic of the new noise directive is to establish a clear and coherent prevention strategy capable of protecting the health and safety of workers exposed to noise.
Article 5(1) of the directive requires that, taking into account technical progress and the measures available to control the risk at source, ‘the risks arising from exposure to noise shall be eliminated at their source or reduced to a minimum’. In order to avoid irreversible damage to workers’ hearing, the directive foresees exposure limit values of 87 dB(A) and a peak sound pressure of 200 Pa, above which no worker may be exposed; the noise reaching the ear should, in fact, be kept below these exposure limit values. The directive also foresees upper and lower exposure action values of respectively 85 dB(A) (and 140 Pa) and 80 dB(A) (and 112 Pa), which determine when preventive measures are necessary to reduce the risks to workers. It is important to note that, when applying the exposure limit values, the determination of the worker’s effective exposure shall take account of the attenuation provided by the individual hearing protectors worn by the worker. The exposure action values shall not take account of the effect of any such protectors….
The directive also foresees detailed rules for the information and training of workers who are exposed to noise at work at or above the lower exposure action value.
Reinforced health surveillance is one of the main points of the directive: it confers, in particular, a right to the worker to have his/her hearing checked by a doctor or by another suitably qualified person under the responsibility of a doctor when the (132) Replacing Directive 86/188/EEC. 6.1. Noise in figures EUROPEAN AGENCY FOR SAFETY AND HEALTH AT WORK 99 upper exposure action values are exceeded. Preventive audiometric testing shall also be available for workers whose exposure exceeds the lower exposure action values, where the assessment and measurement of the noise exposure level indicate a risk to health.” (European Agency for Safety and Health at Work, Risk Observatory, Thematic Report 2, Noise in figures, Retrieved on October 25, 2018)
The new Noise Directive 2003/10/EC therefore reduces the exposure limit value from 90 dB(A), as set up in 1986 directive, to 87 dB(A), which represents clear progress.
Britain HSE allows users to calculate their daily doses of noise.
What are the Negative Effects of Noise?
Hearing loss can be categorized by which part of the auditory system is affected. There are 3 basic types of hearing loss: sensorineural, conductive and mixed
Sensorineural Hearing Loss – occurs when there is damage to the inner ear (cochlea) or hearing nerve in the brain.
Conductive Hearing Loss – occurs when sound is not conducted efficiently through the ear canal, eardrum or middle ear.
Mixed Hearing Loss – occurs when there is a combination of both sensorineural and conductive issues. In other words, both the middle ear and inner ear are affected.
Some causes of sensorineural hearing loss include:
Aging – gradual age-related hearing loss is called presbycusis
Excessive exposure to loud noise
Viral or bacterial infections
Certain Medications
Meniere’s Disease
Acoustic Neuroma a tumor which is located between the ear and the brain
Hereditary factors
Infection of the ear canal or middle ear
Fluid in the middle ear
Perforation or scarring of the eardrum
Wax build-up
Dislocation of the ossicles (three middle-ear bones)
Foreign objects in the ear canal
Otosclerosis
Unusual growths, tumors
Excessive exposure to loud noise can be caused by a one-time or by repeated exposure to loud sounds or sound pressure over an extended period. Sound pressure is measured in decibels (dB). If a sound reaches 85 dB or stronger, it can cause permanent damage to your hearing. With extended exposure, noises that reach a decibel level of 85 can cause permanent damage to the hair cells in the inner ear, leading to hearing loss. Damage happens to the microscopic hair cells found inside the cochlea. These cells respond to mechanical sound vibrations by sending an electrical signal to the auditory nerve. The healthy human ear can hear frequencies ranging from 20Hz to 20,000 Hz. The high frequency area of the cochlea is often damaged by loud sound. Exposure to high levels of noise can lead to:
Hearing loss;
Tinnitus (ringing in the ear);
Stress;
Anxiety;
High blood pressure;
Gastrointestinal problems; and
Chronic fatigue.
Worker’s Rights and Penalties
Workers have the right to:
Working conditions that do not pose a risk of serious harm.
Receive information and training (in a language and vocabulary the worker understands) about workplace hazards, methods to prevent them, and the OSHA standards that apply to their workplace.
Review records of work-related injuries and illnesses.
File a complaint asking OSHA to inspect their workplace if they believe there is a serious hazard or that their employer is not following OSHA’s rules. OSHA will keep all identities confidential.
Exercise their rights under the law without retaliation, including reporting an injury or raising health and safety concerns with their employer or OSHA. If a worker has been retaliated against for using their rights, they must file a complaint with OSHA as soon as possible, but no later than 30 days.
“Last year, US business paid more than $1.5 million in penalties for not protecting workers from noise.” “…an estimated 242 million is spent annual on worker’ compensation for hearing loss disability.” (www.osha.gov/SLTC/noisehearingconservation/, retrieved on October 18, 2018).
When health care facilities violate the regulations of the Occupational Safety and Health Act of 1970, the consequences the owners face can range from citations to jail time. Typically, the inspections are not planned. If a violation is found, the inspector will give the employer a deadline for fixing it and will issue a citation. OSHA schedules inspections based on several federal, regional, and local administrative priorities, but it also conducts inspections based on whistle-blower complaints and referrals.
If an OSHA violation is not corrected, OSHA will give a minimum fine of $5 000. OSHA can fine an employer up to $7,000 per day for not fixing a violation. The maximum fine for a repeated violation is $70,000. When a serious accident occurs, fines are certain or possible imprisonment.
Below are the penalty amounts adjusted for inflation as of Jan. 2, 2018. (OSHA Memo, 1/3/2018)
Type of Violation
Penalty
Serious Other-Than-Serious Posting Requirements
$12,934 per violation
Failure to Abate
$12,934 per day beyond the abatement date
Willful or Repeated
$129,336 per violation
State Plan States
States that operate their own Occupational Safety and Health Plans are required to adopt maximum penalty levels that are at least as effective as Federal OSHA’s.
For More Assistance
OSHA offers a variety of options for employers looking for compliance assistance including on-site consultation, education programs for employers and workers. Yo su can contact their regional or area office nearest to you for additional information.
Canadian Penalties
“The legislation holds employers responsible to protect employee health and safety. Enforcement is carried out by inspectors from the government department responsible for health and safety in each jurisdiction. In some serious cases, charges may also be laid by police or crown attorneys under Section 217.1 of the Canada Criminal Code (also known as “Bill C-45”). This section imposes a legal duty on employers and those who direct work to take reasonable measures to protect employees and public safety. If this duty is “wantonly” or recklessly disregarded and bodily harm or death results, an organization or individual could be charged with criminal negligence.” (OH&S Legislation in Canada – Basic Responsibilities, retrieved on October 25, 2018)
European Penalties
Penalties can include the following:
Fixed fines
On-the-spot fines
Remedial orders
Probation for companies and directors
“Might be used to underpin health and safety requirements – perhaps so-called ‘paperwork’ requirements: risk assessments, employee consultation arrangements, provisions for safety reps, compulsory insurance possibly, business registration, welfare provisions, and perhaps RIDDOR requirements.
If used in conjunction with improvement notices, fixed penalties might have the effect of helping to change duty-holder behaviour – since, in the absence of a new approach, prosecution is rare in these areas.
For use by enforcing authorities to relieve judicial system”
Alternative penalties including:
“Penalties used instead of, or in conjunction with, criminal prosecution for breaches of health and safety law serious enough to warrant consideration of criminal prosecution, and which, in addition to a punitive and deterrent purpose, might also have a restorative or restitutive element. At present, such penalties are either not available within the health and safety system or are not used.
Such alternatives to prosecution would need:
to fit the purpose of enforcement – that is, be effective in changing the behaviour of duty-holders and achieving improvements in health and safety outcomes, and
to satisfy the principles underpinning the Health and Safety Commission’s (HSC) Enforcement Policy: proportionality, targeting, consistency and transparency.”
Here at Nex Flow, we take noise levels into consideration very seriously because we understand that reducing noise levels from very loud and damaging compressed air equipment is important. Compressed air technology is used for cooling or blow off applications. Properly engineered air nozzles and air amplifiers can reduce noise levels by 10 dBA and air knives can operate under 70 dBA for blow off applications.
Where compressed air is exhausted from exit ports, mufflers may be added to reduce noise levels. The mufflers that perform optimally are ones with a Coandă profile used to entrain surrounding air along with the compressed air released, which converts pressure to flow. The conversion accomplishes three things: noise levels fall dramatically, energy consumption is reduced, and a laminar flow is maintained at a greater distance than from an open pipe, tube or hole so the nozzle or other blow off device is effective at a much greater distance.
Sound level is proportional to the velocity of the compressed air flow exhausted by a factor to the power of 8. . Sound Level ∞ Velocity 8 After mufflers are installed, the velocity can be reduced, which minimizes noise levels and also saves energy.
Conserve energy by turning off the compressed air tool when not in demand. This will also reduce noise in the workplace and save money.
Noise controls should reduce hazardous exposure to sound so that risk of hearing loss is eliminated or minimized. Not only will hearing loss be avoided, but communication between workers will improve. Air conditioning noise is unavoidable but investing in a new unit or noise absorbing equipment can reduce the noise output. Vortex Tube operated Cabinet Enclosure Coolers (Panel Coolers) operate under 80 dBA but have optional sound reducing packages to reduce noise levels to under 65 dBA. The noise measurement is typically taken about 3 feet from the source.
Modify, maintain, or replace aging equipment. Older air conditioners can collect dirt and other blocking materials over time. Best practices clean the air filters regularly. Internal parts, such as bearings of a fan motor, should be cleaned by a qualified technician. Fan motor bearings can also be adjusted to reduce noise. Vortex Tube operated Cabinet Enclosure Coolers (Panel Coolers) do not have these issues and offer advantages of near zero maintenance over traditional air conditioners for electrical and electronic cabinet enclosure cooling. They can be used in factory environments and only when compressed air is available for their operation. Other advantages they offer is no CFC’s or HCFC’s, keeping control panels at a slight positive pressure to keep out dirty environmental air, and no condensate. They maintain noise level consistently for years if the compressed air supplied is kept properly filtered.
Relocate noise-producing equipment (e.g., freezers, refrigerators, incubators and centrifuges) away from workers. Provide acoustic treatment for ceilings and walls. Controlling noise exposure through distance is often an effective, yet simple and inexpensive administrative control.
Note: Doubling the distance between the source of noise and the worker, the noise is decreased by 6 dBA.
Lower ceiling height to prevent sound from traveling and bouncing off surfaces, therefore amplifying noise.
Treat the noise source or the transmission path to reduce the noise level at the worker’s ear. Examples of inexpensive, effective engineering controls include:
Use low-noise tools and machinery
Maintain and lubricate machinery and equipment (e.g., oil bearings).
Place a barrier between the noise source and employee (e.g., sound walls or curtains).
Enclose or isolate the noise source.
Operating noisy machines during shifts when fewer people are exposed.
Limiting the amount of time, a person spends at a noise source.
Providing quiet areas where workers can gain relief from hazardous noise sources (e.g., construct a soundproof room where workers’ hearing can recover – depending upon their individual noise level and duration of exposure, and time spent in the quiet area).
Restricting worker presence to a suitable distance away from noisy equipment.
Have workers use hearing protection devices such as earmuffs, plugs
Whenever worker noise exposure is equal to or greater than 85 dBA for an 8-hour exposure or in the construction industry when exposures exceed 90 dBA for an 8-hour exposure, the employer is responsible for implementing a hearing conservation program:
Identify which employees are at risk from hazardous levels of noise.
Informing workers at risk from hazardous levels of noise exposure of the results of their noise monitoring.
Providing affected workers or their authorized representatives with an opportunity to observe any noise measurements conducted.
Maintaining a worker audiometric testing program (hearing tests) which is a professional evaluation of the health effects of noise upon individual worker’s hearing.
Implementing comprehensive hearing protection follow-up procedures for workers who show a loss of hearing (standard threshold shift) after completing baseline (first) and yearly audiometric testing.
Proper selection of hearing protection based upon individual fit and manufacturer’s quality testing indicating the likely protection that they will provide to a properly trained wearer.
Evaluate the hearing protectors’ attenuation and effectiveness for the specific workplace noise.
Training and information that ensures the workers are aware of the hazard from excessive noise exposures and how to properly use the protective equipment that has been provided.
Data management of and worker access to records regarding monitoring and noise sampling.
How does Nex Flow products reduce noise levels?
Compressed air exhaust air is a source of noise and why noise reducing products, such as air nozzles, air knives and air amplifiers are used in factories. To protect workers from excessive and damaging noise levels, the excess noise can be reduced up to 10 dBA.
The X-Stream® Sound Level Meter is used to measure and monitor the sound level in all types of industrial environments. The handheld accurate meter, which has data collection, is used to identify noise problem areas that may be intermittent. It is used for compressed air exhaust noise measurement and identifies where costly and inefficient blow off can be replaced by energy efficient Nex Flow®blow off products.
Nex Flow manufactures specialized compressed air solutions that are easy to install and reliable. All products offer noise reduction in factories to enhance the safety of your environments. Nex Flow manufacturers high quality, economical, specialized compressed air solutions for blow, off, cooling, drying, and moving with representatives worldwide. Choosing Nex Flow means that you obtain the best customized solution, including full technical support. Our customer technical support provides blowing angle and direction tips during installation. All compressed air products have a five-year warranty against manufacturer’s defects.
An air nozzle controls the direction or characteristics of air flow by converting pressure into the flow. Air Nozzles are the smallest air amplifiers for point application. Frequently Nozzles control the flow rate, speed, direction, mass, shape, and pressure of the stream that emerges. In a nozzle, the velocity of fluid increases at the expense of its pressure energy. Air nozzles are one of the most common products used in a factory environment. They are primarily used for blowing off debris and liquid and for cooling or drying parts. It is using them for cleaning, part ejection, and conveying.
The original compressed air-operated engineered nozzle is a cone that provided the most flow amplification. They are helpful for compressed air applications because they entrain surrounding atmospheric air with the compressed air.
It is often a pipe or tube of varying cross-sectional area and can direct or modify a fluid’s flow (liquid or gas). Inefficient air nozzles consist of an air exit hole for the compressed air at the end of a pipe attachment. The pipe usually has a small hole on the side to release compressed air, reduce dead-end pressure, and create a helpful blow-off force.
NOTE: Always use filtered compressed air to ensure the air supply remains clean and dry.
Properly engineered air nozzles work by using the Coandă effect – entraining surrounding air and the compressed air in a ring of holes around the bottom or sides of the nozzle. The exiting air is a concentrated, high-velocity, laminar flow stream of amplified air. Standard cone-shaped air nozzles, with air exit holes around the bottom of the nozzle, provide the best flow per unit of air consumption and are best suited for light blow-off and cooling applications, thus providing a low-cost solution for the task. Modern engineered nozzles have holes on the bottom or sides with hole spacing, sizing, and internal design crafted to optimize for the highest force per unit of air consumed.
NOTE: Always use filtered compressed air to ensure the air supply remains clean and dry.
Types of Nozzles
In most factories/manufacturing environments, many types of nozzles satisfy the requirements for specific applications. The challenge is to find the nozzle that provides the best performance at the optimal operating cost.
There are several types of engineered nozzles available:
Cone Shaped Air Nozzles are excellent flow amplifiers. They are used for cooling because they have high flow/CFM compared to other engineered nozzles. They dramatically reduce noise pollution in a factory and are suitable for energy conservation. Cone-shaped air nozzles reduce compressed air costs by conserving air. They are compact and have a 10-dBA average noise reduction to improve safety in the work environment. They meet OSHA noise level requirements. Overall, these air nozzles will enhance the production of your factory environment. These Air Nozzles replace an open pipe from 2 mm to 0.5 inches and save 30% in compressed air. Note that not all cone-shaped nozzles are equal, as the internal design impacts performance.
Air Mag Air Nozzles is a bullet-shaped finned nozzle with a unique patent design to focus compressed air from the supply line and entrained air from the surroundings to a sharper laminar flow of air with the highest force per SCFM than other bullet-shaped finned nozzles on the market. They have the lowest air consumption for the force produced, lower noise levels, no whistling sound, are rugged, and are made of a single piece for extra strength. The exit nozzle is oriented to increase force/CFM over other competitive nozzles by 10%. The Air Mag Nozzle comes in the following sizes for various applications:
1/4″ is the average size for air guns. This size is used for most applications and is usually attached to a ¼” pipe or hose.
½” is for heavier blow-off applications. It connects to a ½” pipe or hose and is a standard nozzle used with large air guns.
4, 5, and 6 mm are available for small applications and are usually attached to small copper tubes and smaller – often low-cost – air guns. There is a 1/8″ adaptor for the 6 mm nozzle to adapt it to a 1/8″ pipe.
More types include
A flat Jet Nozzle is a compressed air-operated chamber (flat nozzle, flat jet), which is a smaller length than an air knife. It also has a higher air force and flow design. They are mounting the flat jet nozzle on manifolds of different sizes (holding 2, 4, or 6 units typically or more). Also, use it when a much stronger forced air is required than an air knife can provide. They are very efficient and specially designed to provide a powerful stream of high-velocity laminar flow, a high force for blow-off applications, and cooling where air knives do not provide enough force. The air consumption and noise levels are minimized with the unique design, which converts pressure usually lost as noise and pressure drop into proper flow and energy. Shims can be added to modify the force. This nozzle is used for part cleaning, chip removal, part drying, part ejection, and air assist. Nex Flow takes care in designing our flat jet nozzle and ensures it meets the OSHA noise level requirements.
Ring Ionizer-Ionizing Nozzles discharge and clean surfaces of non-conductive materials by incorporating an anti-static pin. For manual use, mounting to a handgun is possible.
Laval Effect Nozzle uses an hourglass exit for the existing compressed air to accelerate the exiting compressed air. While they are supposed to reduce overall noise, they tend to have a higher-pitched noise. The force tends to dissipate if the nozzle is not close to the target blow-off. For this type of nozzle, the noise and effectiveness are questionable compared to a nozzle using the Coandă effect.
Spray nozzles that use compressed air produce a fine spray of liquids mixed with the compressed air. They include atomizer nozzles and air-aspirating nozzles.
Materials Used to make Nozzles.
Choosing the material that the nozzle is constructed of will determine the unit’s wear. Nozzles, over time, could begin to clean a surface unevenly or over-spraying, which wastes chemicals, water, energy, and operating costs.
Anodized aluminum is ideal for blow guns and part ejection of heavier viscosity liquids.
303/304/316L Stainless Steel is often used for liquid and lightweight part blow-off applications for food, pharmaceutical, and corrosive environmental applications. 316L stainless steel is more expensive but worth the cost when the manufacturing environment has high chloride and salt exposure.
Cast zinc is rugged and provides extra strength for use in harsh environments.
Plastic nozzles are of lower cost and are often used but can easily break and, in some applications, may be dangerous with the risk of breaking.
Copper or brass are optimum for blow-off nozzle materials since they have low friction coefficients.
Advantages of Using an Air Nozzle
Using air nozzles, replacing non-engineered air nozzles, or replacing old nozzles with more efficient products can save high operating costs by using compressed air more effectively. There is also an average 10 dBA reduction in noise, and it meets OSHA standards, which improves the working environment. Nozzles provide precise, repeatable drying and blowing-off capabilities for all applications.
Accessories
Air nozzle is available with the following accessories:
Copper tubes can be attached to some nozzles to aim the direction of the flow. The copper tube is pressed to fit into the customer’s existing system.
A rigid-flex hose can be bent into shape to aim the nozzle at the target. It is an all stainless-steel hose that does not break after a few bends like competitive rubber hoses with simple copper inserts. The stainless-steel construction allows for use in any challenging environment. Rigid-flex hose nozzle is resistant to creep and crimping.
Manifolds to attach more than one nozzle or flat jet nozzle
Swivels
Regulators
Pneumatic Super Separator
Magnetic base
PLC Flow Control System (PLCFC)
Static meters (used with Ionizing nozzles)
Factors to Consider when Selecting a Nozzle
When considering an engineered nozzle, there are several factors to consider. It is recommended, when reviewing specification, to research the distance the force/CFM were taken and the line pressure. Determine if the force and pressure are suitable for your application: test and use brands known for improved performance and quality like ours. Stay wary of copies and ask if you need continuous or intermittent air supply.
Don’t forget to consider sensors and timers when applicable for energy savings. Besides the nozzles themselves – it is also essential to consider the compressed air piping system to ensure efficiency.
Lubricants corrode some materials from the compression process, which leads to leaks and particulates in the air stream. Copper, brass, steel, and aluminum are optimum choices for nozzle materials as they have low friction coefficients.
How do you determine the best nozzle for the following applications?
Cleaning
For cleaning applications, choose a nozzle with the highest force/unit airflow (Force/SCFM ratio), such as the Air Mag nozzle. It is also essential to consider air consumption. A regulator can be used to cut back the pressure to set the required force. Any additional force above the requirement will use more energy and cost more. Air pressure loss will result from compressed air through a pipe attached to a nozzle.
The higher the airflow through the pipe, the larger the pressure drop and pressure at the entrance of the nozzle. Any extra pressure (for example, 1 SCFM) entering the piping that is the same size as the nozzle – will cause the pressure to drop at the entrance of the nozzle. Therefore, for cost savings, the correct pressure/force must be determined at the entrance of pipping attached to the nozzle so that there is no pressure drop when the compressed air enters the nozzle.
The reduced air pressure/force will also have less noise pollution and provide a safer manufacturing environment for your employees. Air Edgers (Flat Jet nozzles) are also popular for cleaning flat or curved surfaces and have the advantage of having the force varied by adding/removing shims, which control the air exit volume and force.
Other factors that can negatively impact spray nozzle performance are plugging, erosion, corrosion, scale build-up, caking, accidental damage, and improper assembly. These are common in washing and rinsing operations, especially when using caustic solutions. Establishing and implementing a nozzle maintenance program is the most effective way to prevent and minimize costly spray nozzle problems.
Static Control – Ion air nozzles/Ring ionizer nozzles are highly effective at discharging and cleaning non-conductive materials. These nozzles can be mounted on handguns for confined workspaces. These are flexible, light, and easy to use for discharge processes.
Drying
When nozzles are used for drying, the traditional cone-shaped nozzle is recommended. For larger applications requiring several nozzles, more energy will be saved when using the Air Mag nozzles. Anodized aluminum or 303/304 Stainless Steel standard strength nozzles with 1/8″, ¼”, male NPT connection is ideal for blow-off liquids applications. Model 47001 is designed to fit into small spots and is used by many machine builders for blow-off applications. Model 47003 (anodized aluminum), Model 47003S (303/304 Stainless Steel), and Model 47003S-316L (316L Stainless Steel) –with a 1/8″ male NPT connection is ideal for most blow-off applications involving liquids.
Drying large flat or curved surfaces
Air Knives are like rows of linear air nozzles that can be made to very long lengths. Air knives provide uniform airflow across the entire length of the air knife. It provides high velocity and a constant air stream for fast drying and blow-off in a factory setting. Air knives are maintenance-free because there are no moving parts. They are safe because they have low noise pollution. Air knife kits are available, which include an air knife, extra shims, filter, pressure regulator, and gauge.
Cooling
Using standard cone-shaped air nozzles that are efficient at converting pressure to flow is a good choice when selecting nozzles for cooling. These nozzles are better for cooling as they have less force/CFM but more flow/CFM than the more engineered nozzles. Round air amplifiers are essentially very large low-pressure but high-volume nozzles ideal for cooling molded parts and castings. They move large volumes of air using a small amount of compressed air, making it economical to operate.
Ejection of Heavier Liquids
Model 47004 (anodized aluminum), Model 47004S (303/304 Stainless Steel), and Model 47004S-316L (316L Stainless Steel) are a strong force and high flow amplification nozzles with a 1/4″ male NPT connection is ideal for most blow-off applications involving liquids and even lightweight parts and often used for heavier liquid. The 47010 is a higher-force nozzle but has less distance for laminar flow than the 47004. It has an anodized aluminum ¼” female NPT fitting nozzle with a Coandă profile resulting in extremely strong force at a distance. This nozzle is good for blow guns. It has a higher force for less distance for laminar flow.
About Nex Flow
Nex Flow manufactures specialized compressed air solutions that are easy to install and reliable. All products reduce noise in factories to enhance the safety of your environment. Nex Flow manufactures high-quality, economical, specialized compressed air solutions for blow, off, cooling, drying, and moving with representatives worldwide. Choosing Nex Flow means obtaining the best-customized solution, including full technical support. Our customer technical support provides blowing angle and direction tips during installation. All compressed air blow-off, moving, and cooling unit products have a five-year warranty against manufacturer’s defects.
Compressed air is a tricky technology to deal with because it is a compressible fluid and is subject to all sorts of things. Yet 70% of all compressed air is still sued for blow-off and cooling because it is versatile. But it can be used more efficiently.
One of those applications that can be much more effective is when using engineered compressed air nozzles. Properly designed engineered nozzles work by entraining surrounding atmospheric air and compressed air to convey energy normally lost as pressure drops and noise. But not all air nozzles are engineered. And some engineered nozzles are not very well designed. This may not matter in small applications, but when you add up the nozles in a large facility, it can be a significant amount of money.
The first thing to decide is if you want to cool a part or clean it. In the first case, flow is more important than force. In the second case, force is more important than flow. Then there is comparing air nozzles. Assuming that manufacturers are honest about their specifications (which is not necessarily the case), you need to look at both force and flow.
This is far more critical when force is required. In this case, the force/unit air consumption is the best thing to look at. The most efficient (and effective) nozzle will have the highest force/unit airflow (Force/SCFM ratio). It does not matter how force can vary among a variety of nozzles because in a proper installation, you use a regulator to cut back the pressure to set the force you need; Force above what you need only uses more energy. But in real life, here is where it gets tricky…
How Piping Can Effect Air Nozzle Performance
Let’s assume you have an installation with a set of nozzles from one supplier. You find a second brand that gives the same force at the same pressure. And the cost for the nozzle is a bit less. You have no regulator on your system. So you replace a few nozzles. But…. then you find that the actual force is less than specified? Yes, according to what you read, it should be the same! What went wrong?
If you check the specifications further, you will find that the replacement nozzles use only 1 SCFM more than the one you are using. It certainly does not seem much, but…. that extra flow going through the piping, which is typically the same size as the nozzle, can cause enough extra pressure drop that the effective pressure at the nozzle entrance is just a little less, which also makes less force. That is how sensitive the nozzle effectiveness can be. So if you are replacing any nozzles, check the force created at a particular pressure and the air consumption at that pressure. The odds are that the pressure at the entrance to the nozzle is NOT the same as you think it is due to pressure drop.
When considering the use of compressed air nozzles, consider the force it produces, usually specified at a particular pressure, and the air consumption.
Nex Flow manufactures products for compressed air blow-off, cleaning, drying, moving, and cooling and also offers related products for filtration and optimization in addition to consultation in their field.
It is popular now to use the term “engineered”air nozzle for compressed air nozzles used for blow-off applications. But what is an engineered nozzle? The original close air-operated engineered nozzle is a cone shape that draws in surrounding air utilizing the “Coanda” effect and converts pressure to flow by removing atmospheric air and the nozzle’s compressed air. Copies and different physical sizes abound in the marketplace, but are they really engineered? The size, the angle of the hole, and even how the air flows inside and out of the air nozzle are essential. It can be easily proven by taking two similarly looking cone-shaped nozzles from different manufacturers and testing them side by side. Even if they look similar on the outside, they may perform dramatically differently, perhaps being louder (or quieter) and the other more (or less) powerful. A truly engineered version will consider inside and outside flow characteristics. But these cone-shaped designs generally provide the most “flow” amplification.
For most applications, however, force is more important, so a high ratio of force/air consumption (CFM) is essential. The “bullet” shaped finned nozzles with holes in between the fins seem to provide this optimum force/cfm better than the cone-shaped versions. The bullet shape still entertains the Coanda effect to accelerate outside air to produce more flow. As with the older designs, the number of holes, their size, overall shape, and fin design are essential but also the way the air flows on the inside. Copies of these bullet-shaped nozzles have also appeared but rarely perform even close to the original designs because they are poorly copied and not engineered. As with the cone-shaped styles, this can be quickly confirmed by taking two similar-looking nozzles from two manufacturers and comparing the force each produces at the same line pressure. The copy rarely does as well.
What Is An Engineered Air Nozzle Really!!
A few years back, so-called Laval effect nozzles, which have the compressed air exiting the nozzle using an hourglass-shaped exit to accelerate the exiting compressed air, appeared on the market. However, it is questionable whether they are any more practical for a higher force/cfm ratio than nozzles using the Coanda effect, incredibly if not close to the target of the blow-off. Noise is another factor with this style of the nozzle.
A bullet-shaped nozzle developed by Nex Flow Air Mag nozzle series is patent pending where the air exit nozzles are oriented in such a way as to increase the force/cfm over the best competitive nozzle found by about 10% and make it more effective at a greater distance. This is truly an engineered nozzle, and all factors, both inside and out, are considered. At the time of this writing, the available Nex Flow Air Mag sizes are 1/4″, 1/2″ but 4, 5, and 6 mm small nozzles are pending. A 1/8″ adaptor for the 6 mm nozzles will also be available.
So when looking at engineered nozzles, carefully research the actual force/CFM, at what distance and line pressure the specifications are taken, and the distance of their effectiveness to make sure it is genuinely engineered and will be suitable for your application. Stay with brand names like Nex Flow to assure quality and be wary of copies.
Nex Flow Air Products Corp. manufactures compressed air technology for blow-off, drying, cleaning, cooling, and moving and constantly strives to improve its products” performance and quality.
Laminar Flow is necessary in compressed air blowoff for effective blowoff applications. Nex Flow designs and manufacturers their compressed air blowoff technology to maximize effectiveness while minimizing energy use and noise levels.
