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.
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
WHY NEX FLOW RING BLADE AIR WIPES ARE SO MUCH BETTER THAN COMPETITIVE OLD TECHNOLOGIES AND EVEN OTHER OPTIONS
Older technology compressed air operated air wipes are built from UHMW blocks or similar material. These air wipe or circular air knife usually have a hinge to open and close the block around the extruded material which has some air holes drilled into it. With this style it is often tout that it uses less compressed air for blow off. However, in practice you normally need more than one unit. It may take as many as five units of this style to do the same job as a Nex Flow Ring Blade air wipe, so you actually end up using much less compressed air. In addition to being more effective, the Ring Blade air wipes are typically much less expensive and produce even a lower noise level.
Let’s compare a typical situation. Take two units of a ½” UHMW version which uses 8.3 SCFM each or a total of 16.6 SCFM at 80 PSIG. Units of this design can produce noise levels of 85 dBA. One Nex Flow Model 20000 – ½” Ring Blade air wipe only requires 14 SCFM at 80 PSIG with a noise level of 75 dBA and can easily remove water from an extrusion in a single pass. Only one is required. The question is often asked “how many do you need” and the answer depends on many factors such as the smoothness and surface tension of the liquid on the surface of the material to be removed, speed and the distance from the air wipe to the material surface. The 360 degree uniform “amplified laminar flow” of air removes liquid evenly and quickly.
Nex Flow air wipes come in aluminum with rubber hose connecting each half of the mated semi-circular parts, or aluminum with brass fittings and stainless hose for temperatures up to 400 degrees F and in 316L stainless steel with a braided stainless-steel hose and fittings for temperatures up to 800 degrees F and for highly corrosive environments. Nex Flow Ring Blade can reduce noise levels compared to older designs by as much as 10 dBA.
Old technology plastic block air wipes that are used for larger diameter extrusions tend to be longer and take up more space. They can still be loud at over 80 dBA as well. The Nex Flow Ring Blade design is much shorter and compact, even for large diameters and can still reduce noise levels significantly while doing a better job in drying with less number of units and less space for each installation.
Blower operated may offer lower energy consumption, but the same issues can arise in blow off. The biggest complaint from such systems is insufficient drying (just as in the old plastic block design), requiring multiple units, much higher noise levels, and a higher footprint. All this leads to higher capital cost, and increased maintenance which can offset energy savings. When the job really needs to be done, the Nex Flow Ring Blade is an obvious choice.
The Nex Flow air wipes use a special series of Coanda angles to convert noise and pressure drop high velocity flow. The angles and even the positioning of how the air exists the plenum chamber and goes over the angles can make a difference. One of the factors to consider is something called “blowback”. This is where the air existing the air wipe can actually reverse flow at some point. Some designs similar to the Nex Flow Ring Blade do not seem to take this effect into account but we do. Each Nex Flow unit is designed to avoid this “blowback” effect and perform optimally when drying extruded parts.
NEX FLOW RING BLADE AIR WIPE – COMPACT, EFFICIENT and QUIET and can clean and dry even complex shapes as this photo shows. Two other important factors should be considered when comparing designs similar to the Ring Blade: One is that Nex Flow always uses stainless steel shims to maintain the air gap for longer life rather than plastic shims used by competitors. Secondly, all aluminum Ring Blades are anodized (most competitive units are NOT), again for longer life and metal protection. Stainless steel units are not just 303/304 stainless but are higher quality 316L stainless steel making them the best choice for applications like drying medical tube extrusions. All this at generally a much lower cost.
When using Nex Flow Ring Blade air wipes for all sorts of extrusions their design can even address complex shapes such as EPDM profiles like the trim on an automobile. The angled high velocity flow will get into corners and crevices to help dry in many cases, even at high speeds.
So when considering air wipes (air knives arranged in a ring shape), and even when checking existing systems, the things to consider are the number of unit being used (or being considered to use), space or footprint cost, noise levels and actual (or expected) performance.
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.
An air wipe is a blow off product used to dry, cool, and clean an extruded product or any other piece that is fed through the unit. The Nex Flow® Ring Blade® air wipe is compressed air operated and designed such that the compressed air exits the unit over a series of Coanda angles, which entrain a large amount of atmospheric air that mixes with the exiting compressed air, thereby amplifying the air flow at a high velocity to blow off liquid and dirt from the surface of the part being fed through the unit. The Coanda effect essentially converts what is normally lost as pressure drop into flow. This also reduces exhaust noise dramatically. Air wipes normally come in “split mode” which means they actually consists of two pieces held together by some means but perfectly matched so each section covers 180 degrees for blow off. Together they form a 360 degree blow off system. The air is typically directed at an angle to be able to shear off the liquid or other material on the surface of the parts to be cleaned. The Ring Blade® air wipe has the air exiting at a 30 degree angle to the direction of flow of the part that is fed through the system. This gives it the most ideal shearing angle to clean and dry. The part being fed through does not have to be perfectly smooth nor even cylindrical – it can be quite a complex shape (which is true with automotive EPDM profiles for example) and still be dried very well as long as the air hits the surface.
Some common uses for drying extruded items include:
Wire
Cable
Window Profiles
Automotive EPDM trim
Rope
Other uses are for cleaning tooling manufactured that is fed through the device to be cleaned and dried, and steel pipe being manufactured and fed through the system – basically anything that would fit through the unit.
One rule that is important is to have the part that is fed through the air wipe to be as close to the wall of the system as much as possible without touching the wall. Ring Blade® units for example come in various standard sizes with an inside diameter of ½”, 1”, 2”, 3”, 4”, 5”, 6”, 7”, 9” and 11”. Special sizes such as 1-1/2” have been produced as well. The further the piece is from the insides wall of the air wipe, the lower the force. So if the part to be dried is – for example – a 1-3/4” X 1-1/2”rectangular shape you would feed it through a 2” Ring Blade® air wipe and not through a 6” unit. Also, it would make sense to keep the unit as small as possible as air consumption goes up with the increase in size. Having said that, if the product is moving slowly through the system, you can often go a size larger. If going at high speeds however, you generally need to have the walls closer to the piece being cleaned or dried.
One way to deal with very fast speeds through the Ring Blade® air wipe is to open the air gap with an extra shim that maintains the air exit size. This can also make it possible to clean and dry small sizes through a larger internal diameter systems. However, this does increase compressed air consumption. For very high speeds it is preferable to have a second unit downstream the first one for secondary application. It should be downstream far enough so the he air from one unit does not interfere with the air flow of the second.
A question sometimes comes up is whether an air wipe can be held hand. It would most likely be very difficult to hold by hand larger diameters but for smaller ones this can be done. For example, if there are many pieces that can fit through an air wipe, but for some reason are not able to be fed through a system, then these pieces can be placed vertically on a table (or floor) and the air wipe passed over and down through these pieces to dry and clean. The blow off force will be such that you need a good grip when using it this way, but not impossible to do so. Some items which need cleaning or drying, that are now cleaned or dried with air guns might be suitably shaped where an air wipe can be used to do the job faster and easier. This is because an air gun does not give the coverage and therefore the person handling the unit has to do a great deal more movement. If the shape can be put through the system, it can be used manually. However, if there are enough parts, it is usually more economical to set up a feeding system.
The Nex Flow® Ring Blade® air wipe is very similar to the Nex Flow®Standard Air Blade® air knife. In the Standard Air Blade® air knife the compressed air exits a gap in the air knife and goes over a series of Coanda angles that bend the air and entrain the surrounding atmospheric air to amplify the air flow. The air wipe is basically this same design curved and then altered so that the 360 degree flow exits at a 30 degree angle to have the high velocity air produced converge at some point away from the unit. This provides an ideal shearing force against any part that enters the air wipe so get into crevices and corners of odd shaped parts to be able to clean, dry and cool. Special systems have been made as one piece systems and even at special shearing angles per customer requests and special applications. However, the normal units are supplied as two 180 degree pieces joined together by hinged units to easily “open” them. The reason is that most applications are from extruded parts. Some of these extruded parts such as EPDM rubber profiles on startup form a big bubble that is larger than the normal dimensions. This allows the air wipe to be “opened” to feed the bubble through as the extrusion proves begins. Similarly it is in two pieces to address knot in wire drawing and other possible applications where such bubbles or material buildup needs to be dealt with, without cutting into a continuous extruded line.
While Nex Flow®manufactures units up to quite a large diameter (11”), to go any larger can be a manufacturing challenge. But, as the diameter or shape that needs to be addressed becomes larger, it can often be easily addressed with a ring of Air Blade® air knives instead because the larger the part, even a round shape like a pipe approaches that of a relatively flat but curved surface. This is why air knives can just as easily address those large parts. But when the part is smaller, (and generally moving at very high speeds as well), the air wipes can do a much better job of drying, cleaning and cooling.
Air wipes are quiet, have low air consumption, have uniform airflow across the entire diameter, have no moving parts, use no electricity, compact and easy to install. They are non-contact drying/cleaning devices.
The material of construction can be important. The Nex Flow® Ring Blade® air wipe comes in three standard material constructions: aluminum body with a stainless steel shim set to maintain the air exit gap, brass fittings and a strengthened rubber hose to connect the two haves for one air inlet (sizes larger than 7” diameter do not have a connecting hose and air must be fed separately into each half section). This construction is suitable for most applications in regular factory environments and when subjected to temperatures below 150 degrees F or 66 degrees C.
When dealing with higher temperatures up to 400 degrees F (204 degrees C), the rubber connecting hose is replaced with a stainless steel connecting hose.
If subjecting the air wipe to a corrosive and/or a high temperature environment up to 800 degrees F (427 degrees C), the body is made of 316L stainless steel, with 316L stainless steel shims, and 316 stainless steel hose and fittings.
One final note is that the compressed air supplied to the product should be clean and dry. A minimum of 10 micron filtration is recommended for water removal from the compressed air lines and if oil can be an issue, an oil removal filter of around 0.3 micron filtration is recommended. Should the compressed air lines have significant issues of compressed air cleanliness, some options are the Nex Flow® filter or the Super Separator. These quality filtration products operate with no replaceable cartridges and can address such air cleanliness problems.
When choosing a compressed air operated air wipe, recognize the need to keeping the internal diameter of the unit close to the part being fed through the unit, consider the speed of the material being fed through the device, and determine the material needed for the environment in which the unit is being subjected. Plus assure that the supply air is clean with an adequately large airline size to avoid pressure drop. In this way you will have a trouble free, near zero maintenance device to dry, clean and cool the product being put through the system.
