Tag: Cabinet Enclosure Coolers

Understanding NEMA Type 4-4X Panel Coolers for Cabinet Enclosures and the right time to utilize them.

NEMA Type 4 enclosures, equivalent to IP 66 in Europe, resist water sprays and are dust-proof. The 4X version also resists corrosion. Electrical enclosures in corrosive or weathered environments need this standard. NEMA Type 4 or 4-4X rated enclosures require equivalent cooling systems.

Some NEMA Type 4 coolers use an aluminum cover and a stainless steel vortex tube. Others use different metals. Frequent wash downs can corrode the large cover, especially if not anodized. This corrosion comes from residual water. NEMA type 4X units, often made of stainless steel, are more reliable long-term.

NEMA Type 4-4X Requirements

A NEMA Type 4-4X cooler is waterproof, but you shouldn’t submerge it. It must resist heavy water sprays without water entry. UL and ULC rigorously test this for certification. Ensure the cooler has proper approval.

NEMA type 4X coolers undergo rigorous corrosion tests. They face 1200 hours in moist air with carbon dioxide and sulfur dioxide. They also endure 800 hours of salt spray tests. These vortex operated cabinet enclosure coolers, must be dust proof and ice-damage resistant. Often, manufacturers use stainless steel for these devices. Stainless steel best resists corrosion and weathering for the NEMA rating.

Applications for NEMA 4X Enclosures

The range of applications for NEMA Type 4X coolers are many, environments with aggressive conditions to the ability to retain their cosmetic look and maintain functionality under all conditions to which they may be subject. The resistance to corrosion, water sprays and adverse weathering represent three important applications for NEMA Type 4X enclosures.

Corrosive Substances in the Atmosphere

When corrosive gases and vapors are present, NEMA Type 4X enclosures protect electrical equipment and internal devices from contamination and harm. Vortex-operated coolers in particular keep control panels at a slightly positive pressure to keep out contaminated air. Industry examples include wastewater facilities, and factories handling corrosive chemicals.

Corrosion tests may only include certain conditions. Therefore the resistance of seals and the enclosure cooler materials of construction to particularly aggressive chemicals should be verified before using. A NEMA Type 4X enclosure is not suitable for use in hazardous areas where explosive vapors may exist. Such units are of a different design.

Wash Down and Heavy Splashing Areas

A NEMA Type 4X enclosure is ideal in food processing operations when equipment is subject to being washed down with either water or chemical solutions to maintain hygiene standards. It’s also applicable to other facilities that use water sprays like dairies and vehicle cleaning services, and anywhere high-pressure cleaning equipment may be utilized.

In some manufacturing areas, if there is a risk of accidental splashing and contamination of equipment from fluids used during processing, such coolers are ideal. One example is for the pulp preparation locations in paper mills. NEMA Type 4X vortex-tube-operated coolers are especially suitable for use in marine environments where equipment may be exposed to salt water. In marine environments, 316 or 316L stainless steel should be the main construction of Panel Coolers.

All-Weather Outdoor Locations

NEMA Type 4 Panel Coolers are weatherproof and fit for outdoors. However, NEMA Type 3R versions are often cheaper and also outdoor-approved. Specifically, stainless steel NEMA Type 3R or 4X enclosures work well in dusty, wind-abrasive areas. They’re also ideal in hot, humid places like coasts where mild steel corrodes quickly. Using 316L stainless steel designates it as a NEMA Type 4X unit.

Nex Flow manufactures all of their Panel Coolers in stainless steel to offer the best durability for any NEMA Type application: NEMA Type 12 (IP 54), NEMA Type 3R (IP 14) and NEMA Type 4-4x (IP 66).

HEAT DISSIPATION FROM VARIABLE FREQUENCY DRIVES (VFD’S)

Variable Frequency Drives (VFDs) have become a standard part of control panels. Since their development years ago, because of their efficiency, consider their contribution toward the electrical enclosure’s heat load.

Many VFD manufacturers and suppliers sometimes publish power dissipation or efficiency information in brochures.

The efficiency of most VFDs is between 93 to 98 percent, and loses the balance of the energy as heat.

Despite their high efficiency, VFDs generate a significant amount of heat. Unless removing the heat through enclosure cooling, the drives can overheat and trip, causing plant outages.

The power dissipated is calculated by subtracting the efficiency from 100 percent and multiplying the result by the drive’s power consumption.

Estimating the heat loss of a 95 percent efficient, 100 horsepower drive as 5 percent of 100 horsepower equals 5 horsepower or 3729 watts.

Although a 5% estimate for engineering purposes is ordinarily acceptable if a safety factor adds to other losses, obtaining the VFD drive efficiency at the design load from the equipment supplier is much better.

It would help if you also considered the thermal losses from other ancillary equipment, such as DC phrase-shifting transformers, power supplies, and switchgear which may or may not be significant.

The losses from a transformer could be an additional 4 percent of power consumption.

Again, obtaining these figures would generally be from the equipment suppliers.

HEAT DISSIPATION FROM VARIABLE FREQUENCY DRIVES (VFD’S)

If the drive uses braking resistors and is frequently stopped and started, dissipating the power by the braking resistor should also be considered.

Varian Frequency Drive manufacturers specify a maximum allowable operating temperature for their products. In some cases, it is relatively low as it allows for the heating effect of power electronics on the circuit boards inside the drives.

Some manufacturers also de-rate their drives above temperatures of 104 ºF. (40 º C)

Thus it is good engineering practice to design the enclosure cooling for a temperature below the equipment’s maximum temperature to promote long life and minimize the possibility of overheating.

The total enclosure heat load is the total heat dissipation of all equipment items, plus the heat transfer through the enclosure walls. Due to the ambient temperature, local heat sources, and solar radiation. This is true even though there are various ways of calculating this number.

The most effective method is to use an online heat load calculator like the Nex Flow® Panel Cooler Calculator. This will help to address obtaining the heat load.

The heat load is usually the greatest on startup. They are making vortex coolers like the Nex Flow® Panel Cooler popular for VFD cooling because, on average, they only need to operate about 30% of the time.

Because they operate on compressed air, the energy cost is relatively low. And it is often offset by the elimination of filters, dealing with condensate. Also, other factors, such as labor cost for maintenance, as they are essentially maintenance-free.

In modern industrial plants, electronic equipment is used for motor control, and most of not all machines are controlled by PLC’s. The high heat dissipation from electronic equipment exposes control systems to elevated temperatures that make them susceptible to malfunction if too hot, creating unpredictable behavior or failure that could lead to a plant shut-down.

Electrical enclosure temperatures are should be kept well below 106 ºF (41 ºC) to limit the possibility of severe damage to equipment. The heat load from electronic equipment limits the practical use of natural ventilation to cool the electrical enclosures resulting in the adoption of alternate methods.

Fans with Filters

The simplest and often lowest cost solution is to use fans to remove waste heat by circulating ambient air throughout the enclosure. This works provided the ambient air temperature is moderate if the enclosures are well shaded, and when the internal heat generated is low. Filters must be used to keep out dust and debris from the factory atmosphere and need to be cleaned and/or replaced regularly depending on the nature of the plant environment. Normally the cooler air is blown into the bottom of the enclosure, and exits “hot” at the highest point of the control panel. Fans must be sized to provide sufficient airflow to remove the heat generated by the electrical controls.

Again, the use is limited to electrical enclosures with relatively low heat loads, in shaded areas, and where the ambient temperatures are moderate. If the environment is very dusty and even if it contains a lot of oily mist, the replacement of filters can become quite a time-consuming and costly endeavor. This often results in filter neglect, which can create heat removal problems finally resulting in potential damage to the enclosure controls and downtime.

Air-to-Air Heat Exchangers

In difficult factory environments, with moisture, heavy dust is present, and oil or chemical vapor, the cabinet or panel enclosures must be sealed. One method is the use of closed-loop heat pipes.  A heat pipe absorbs the heat inside the enclosure and transfers it to the outside using a thermally conductive, phase-changing liquid under a partial vacuum.  Heat pipes are used extensively in laptops to remove heat from processors for example. Inside the enclosure, the liquid in the heat pipe absorbs heat and converts it to vapor. This vapor moves to the other end of the heat pipe which is outside of the enclosure, transfers the heat to the outside, and changes back to a liquid. The cycle repeats continuously with no moving parts, which makes air to air heat exchangers a relatively low-maintenance solution.  The only components that require electricity are two small fans outside of the enclosure to cool the hot ends of the heat pipes to begin the cooling cycle again.

Although relatively low cost and simple, the cooling application is again limited by the outside ambient temperature in the factory as you cannot cool to a temperature below ambient. Fans involved in cooling the heat pipes still require filters to prevent them from clogging and damage and again, if not replaced, can stop working causing the cooling system to fail.

Air-to-Water Heat Exchangers

If a chilled water supply is available, Air-to-Water Heat Exchangers can offer sub-ambient cooling. The internal components of Air-to-Water Heat Exchangers are normally completely encased within a sealed enclosure, thus providing maintenance-free closed-loop cooling. These systems are ideal for the dirtiest industrial environments where oil mist, dust, and dirt would quickly clog the filters of the earlier mentioned systems. Metal grinding and stamping, automotive brake plants, flour milling, and mining operations are all examples of very nasty environments where the applications for Air-to-Water Heat Exchangers can be applied. Similarly, food processing, especially meat and poultry processing plants where frequent wash-downs are normal, are ideal industries for their use.

A major issue is the quality of the water used. Scale buildup can be detrimental if water treatment is poor or nonexistent rendering such systems unable to remove the heat adequately. With zero discharge regulations in many jurisdictions, water itself is not low-cost anymore and downtime for descaling is a cost that needs to be considered. However, there are some excellent environmentally friendly, and safe descalers on the market such as Alpha Descaler for not only maintenance but also for regular treatment to prevent scale formation.

Air Conditioning the Enclosure

In harsh environments that are also hot and humid and where the enclosure heat loads are high the only workable option is an industrial-grade air conditioner. Traditional air conditioners using chemical refrigerant coolant are designed to work with sealed cabinets and prevent the drawing in of moisture, dirt, or other vapor from the environment. Capacities vary from 1,000 BTU to 20,000 BTU and models are available for standard NEMA 12 enclosures or NEMA 4 and 4X enclosures for harsh and corrosive environments. Options to prevent corrosion in corrosive environments and for outside use in rain and/or snow protection can be used. Due to increasing environmental regulations, new refrigerants have been developed and introduced which have increased the costs of traditional air conditioners along with their development. Costs increase also due to the changing of certain materials such as seals as old seals may be negatively affected by the new refrigerants. Some of these new refrigerants have flammability issues which can be addressed by design changes (again more costly) but have caused concern for their use in some facilities. And, they still have the issue of filter cleaning and/or replacement which – if not done, can cause damage to the air conditioner.

Increasing in use are vortex-tube operated air conditioners. While they require compressed air for use, they use no chemical refrigerant, are simple in design, have no condensate produced, are vibration resistant, keep out the harsh factory environment by slightly pressuring the control panel, and are virtually maintenance-free. There are no external filters as there are no fans to worry about and as long as the compressed air supply is kept clean with proper filtration for the compressed air, these types of air conditioners can work for many years with virtually no maintenance. They are also much more environmentally friendly with no refrigerants and have zero flammability issues. One interesting factor is that in very high-temperature ambient, you can utilize a smaller capacity vortex cooler than you would a traditional air conditioner because a vortex tube operated panel cooler performance is independent of ambient air temperature, unlike a traditional air conditioner. It only depends on the temperature of the compressed air itself. Many vortex coolers like the Nex Flow® Panel Cooler are available for NEMA 12, NEMA 3R (outside use) and NEMA 4-4X enclosures. Nex Flow® has also developed and continues to develop increasingly efficient cooling systems utilizing vortex tube technology and special systems can be made. This type of air conditioner is the most environmentally friendly and user friendly of any air conditioning method.

Enclosure Cooling and Reliability

Reliability is a huge issue in modern times with supply chain issues, lack of adequate labor, and concern over timely responsiveness when issues occur. The greater use of electronics in addition to higher enclosure packing densities has directed the use of enclosure cooling more toward air conditioners. Opting for systems that are better for the environment, and have minimal maintenance is a definite trend. Additional security in large factories is now provided by the installation of remote alarm systems, or by linking the digital controller to a remote web server that can simultaneously monitor several enclosures. This ensures that maintenance personnel is immediately notified of any malfunction to prevent unplanned incidents from becoming plant outages. In smaller operations, monitoring is still primarily by observation. One simple item to assist in monitoring for any heat problem in a control panel is a Temperature Sensing Label supplied with all Nex Flow Panel Coolers. It is placed outside the panel in one top corner and offers a visual indication of potential heat load issues that a passing employee can easily see and then act upon if necessary.

Thyristors and other solid state devices in variable frequency drives generate a large amount of heat up to as much as 6% in some cases, the average for most about 4.5% of rated horsepower. The amount of heat is directly related to the efficiency of the drive.

These solid state units are typically mounted on heat sinks and cooler air is drawn in from the bottom of the control panel and then discharge the hot air at the top of the enclosure.

The removal of this heat under many situations requires the cooling the electrical enclosure and in most circumstances the only viable method is the use of enclosure air conditioners.

Some of these situations are as follows…..

High Panel Temperatures (Over 105 ºF or 40 ºC)

The internal air temperature of an electrical should not exceed 105 ºF (40 ºC) especially as localized temperatures could actually be significantly higher. In fact, the service life of electronic equipment is practically cut in half for every 18 ºF temperature rise above normal ambient temperature.

Near Other External Heat Sources

In applications such as bakeries and steel production, the electrical control panels may be close to very high external sources of heat. A heat source such as a furnace or oven increases the heat load in the drive cabinet enclosure or panel, since the ambient temperature is also elevated. In these locations, only some air conditioner can be effective for cooling an electrical enclosure.

When Exposed to Direct Sunlight

The temperature inside an electrical enclosure situated in direct sunlight will be much higher when exposed directly to solar radiation. Any control panel that sees direct sunlight could absorb up to 100 watts of heat per square foot of surface depending upon the sun’s angle. Reflective paint can deflect much of this solar heat load but, in most cases the temperature inside the enclosure will end up greater than 105 ºF just from the sunlight, without not even considering the additional heat load from variable frequency drives themselves

Higher Level and Mezzanine Floors in Factories

The ambient temperature on a higher level or mezzanine floor in naturally ventilated industrial buildings is usually elevated because hot air is trapped and stratifies under the factory’s roof. The temperature are elevated normally 10 to 20 ºF above the level found on the ground floor. This adds to the heat load in the drive panels to potentially cause premature failure or incorrect operation of the drive. Again, some air conditioner would be required to keep the drive cabinet temperature below 105 ºF.

Corrosive Atmospheres

Electronic equipment is susceptible to corrosion and corrosive atmospheres such as salt spray in marine environments, corrosive chemicals from some production processes, and even particulate containing chemicals that may be in the surrounding air. Drive panels in such environments should have a dust and moisture proof NEMA 4 rating and be provided with a closed circuit enclosure cooling system or some system to keep out the factory environment.

High Humidity Environments

Most electrical drives have a requirement that they are not used in locations where the humidity is high and especially when condensation can occur. In coastal, hot, or humid environments, condensation will easily happen at temperatures close to ambient. A proper enclosure air conditioner will dry the air inside the cabinet, to avoid condensation. If using traditional air conditioners, installing a heater to prevent condensation overnight or during cold periods may be advisable as humidity may stay high and the heating will help prevent the condensation.

 

Cabinet Enclosure Air Conditioner Best for Variable Speed Drives

The high heat dissipation requirements of variable speed drive panels eliminates the use of simple enclosure ventilation systems in any of the above situations.

However it is ideal for relatively low cost vortex tube operated coolers such as the Nex Flow® Frigid-X® Panel Coolers. These devices are produced in stainless steel to handle any potentially corrosive environment and with bypass systems for continuous purging to keep out harsh atmospheres, designed for NEMA Type 12 (IP54), NEMA Type 3R (IP14), or NEMA Type 4-4X (IP66) for almost any type of control panel.

The intrinsic operation of these cooling systems keeps the control panel humidity low to prevent condensation.

While they may have an increased energy use since they operate on compressed air, this is typically offset by the fact that they do not produce any condensate which may be a disposal cost otherwise, use zero chemicals which can harm the environment and which require costly downtime and replacement, and they automatically create a slight positive pressure inside the cabinet to keep our any harmful environmental air – all with no moving parts and essentially maintenance free operation.

Another saving is because of near zero maintenance and absolutely zero use of filters that need replacement, filters that are costly in material, time and disposal after use.

Taken in total, added energy costs in these applications are offset by savings in maintenance time, materials, less downtime, less replacement, and zero disposal costs.

Air conditioners of various types utilized in the USA or Canada are required to meet certain safety standards with similar requirements in most other parts of the world. This is extremely important for industrial applications where they are used as enforcement but by authorities and within companies themselves is on an increasing trend.

Legal requirements governing the use of electrical equipment may sometimes appear complex, certain compliance requirements are clear and universally apply to electrical enclosure coolers.

The most important are the following:

OSHA and NEC Standards

The Occupational Safety and Health Administration (OSHA) governs safety and health in the American workplace and are used as a guide in many other countries many which have similar regulations. In 1971 the National Electric Code (NEC) was incorporated within the Construction Safety and Health Standards of OSHA and therefore all electrical equipment must also conforms to both the safety requirements of OSHA and the NEC. Vortex tube operated control panel air conditioners operate with compressed air. However, they often use electrically operated solenoid valves and thermostats, either as individual pieces or packaged together and these items themselves must meet these safety standards. If a solenoid valve for example is modified, it may be breaking a code. An example of this is drilling a hole in a solenoid to allow for some compressed air flow into an enclosure to keep it purged of environment air instead of using a separate air line for a bypass.

Local Authorities Having Jurisdiction

The Authority Having Jurisdiction (AHJ) that operates locally in the USA is responsible for enforcing local building codes and ensuring compliance. Many of the codes in force by the local authorities are based on the NEC, also known as the NFPA 70. However, others may add local addendums or use their own specific codes.

In all cases, before an installation can be energized the installation must be signed off by a local inspector mandated by the AHJ.

Increasing Importance of Nationally Recognized Testing Laboratories

To ensure that electrical equipment conforms to the relevant codes is to have the equipment certified by a Nationally Recognized Testing Laboratory (NRTL). This certification will be accepted by the AHJ. There are more than a dozen NRTLs licensed in the USA but the most well-known are UL (Underwriters Laboratory) and CSA (Canadian Standards Association).

Before selecting enclosure cooling equipment, make sure that the equipment has been certified and carries the NRTL certification mark. These testing laboratories do more than just “test”. They ensure that the materials used in the products meet a certain standard of quality. One issue with vortex cooler “knockoffs” for example is not only potentially poor quality, but also the use of below standard materials and parts that require a certain level of testing and approval. Anything below “standard” is risky with anything electrical or electronic.

Specific Canadian Requirements

Enclosure cooling systems sold in Canada must conform to the Canadian Electrical Code Part 1. The Canadian Standards Association (CSA) and certain other testing laboratories such as UL are accredited. There are some variations in test requirements and levels of acceptance between the USA and Canada to distinguish between American and Canadian certifications.  UL for example puts a prefix C next to their mark and refers to both the USA and Canada approval. Sometimes both a C and US prefix and suffix is used to identify that the product is tested to the standards of both jurisdictions. It’s important to understand this difference so as to avoid the possibility of installing equipment with the incorrect certification for your region. CSA is based in Canada and again does the same with prefix or suffix identification to indicate approval for one or both jurisdictions. Nex Flow Panel Coolers have been tested and approved by UL to meet both Canadian and USA standards and bear the appropriate mark.

Hazardous Areas

Equipment designed for use in a hazardous area must also be certified as such. Your enclosure cooler must conform to the specific hazardous area rating applicable and must be compatible with the rating of the enclosure on which it is used. Proper wiring and connections should be particularly checked.

NEMA Type Enclosure Rating for the Enclosure and Area

The enclosure cooling system used must have the same or better  NEMA Type enclosure rating than the electrical enclosure itself. These NEMA Type ratings indicate the design level of the enclosure and the cooling system. For example NEMA Type 4 enclosures are suitable for applications and environments where the panel is subject to wash down. The vortex cooler (or whatever cooking is used) needs to be same or better for that wash down environment. Europe uses IP ratings. Various sources can provide the IP rating that is equivalent to the North American NEMA Type rating. Vortex Coolers like the Nex Flow Panel Cooler have versions tested and approved for NEMA 12 (IP 54), NEMA 3R (IP 14) and NEMA 4-4X (IP 66) applications.

In the U.S. and Canada, it is mandatory for certain equipment to carry the mark of an approved testing laboratory, and an enclosure air conditioner is on the list. Verify before you buy and be safe by using properly certified parts and equipment.

When costly electrical and electronic equipment that maintains the operation of a factory go down, production stops. Critical servers and security systems that drive production is of primary importance in a manufacturing operation not only for production but even for employee safety.

Maintaining the right temperature inside electrical and electronic cabinets require a reliable cooling system. Elevated ambient temperatures in a factory environment can cause costly system failure.

1. Reliable Cooling systems enhance the useful life of controls.  When temperatures rise above maximum operating levels, electrical component life can be reduced significantly. A reliable cooling system keeps the panel temperature below the manufacturer’s recommended maximum value, something simple fans and a building’s HVAC system cannot guarantee.

2. Employee Efficiency is increased. Any company wants employee time spent on improving the business and the bottom line, and not dealing with unexpected breakdowns. While the unexpected does happen those related to control panel shutdown can be reduced dramatically with a reliable cooling system.

3. An Ideal Air Conditioning Systems is Maintenance Free or at Least Minimal.  Most cooling systems require regular checks, such as filters on an air conditioned panel. If not changed regularly especially in a dirty environment one of two things can happen: if not changed a dirty filter can cause poor air circulation and overheating or, if the filter is missing, then dirt can get inside an enclosure and coat, and damage controls or at least reduce their lifetime significantly. Too often these things get missed or just ignored due to lack of maintenance time.

4. Prevention is Always Less Costly.  Preventative maintenance starts with machines working in a properly controlled environment. Just as people work better in a better environment, so does equipment. Poor temperature control inside electrical and electronic enclosures is damaging both economically and from a safety perspective. The use of an efficient cooling system is both economically more profitable and much safer to personnel.

Let’s go deeper on each of these points.

Reliability is becoming more important as labor costs and even labor shortage increase over time. It is important that ANY product for cooling is reputable both in quality as well for technical support should anything actually go wrong. But it’s more than just the supplier’s reputation. Any product chosen should consider the factory environment in which it is placed. Utilizing a fan to cool the inside of a control panel in a dirty and hot and humid environment without considering the environment in which the panel exists can invite trouble. The manufacturer of the control panel does not always have control or any say in which the panel is placed. If the environment is nasty then that should have a serious impact on the cooling method chosen.

Employee basic responsibility is to keep the plant operating. This means an acceptable preventative maintenance program and not only just responding when a problem occurs. If problems persist, the more thorough investigation should be made. Too often however, the problem is not addressed and much time and cost is spent fixing things over and over. For control panels, if the panel door is consistently “left open” because it’s just too hot inside the enclosure, then it should be addressed. It is not only unsafe to leave electrified enclosures open while operating, it is also in most placed illegal. Addressing these problems expeditiously can only improve the environment overall as well as reduce downtime and other potential problems.

Labor costs are significant in any production operation and labor efficiency is important. Every time an outside service person is brought in, some employee must escort that person in the factory, perhaps spend time while that person goes thru a safety protocol training and of course, there is downtime when maintenance is done. Even if no outside person is needed for service, there is still a downtime cost when maintenance is performed by employees. If labor cost can be optimized by reasonably priced solutions that are relatively maintenance free, it should be done.

Prevention is helped by a properly maintained preventative maintenance program and can be further improved by monitoring. There has been and continued=s to be tremendous advances in monitoring of all sorts of equipment especially rotating equipment such as pumps and motors. But what about control panels? While so much is spent for monitoring other equipment the electrical and electronic enclosure should not be ignored. It is just as important in any production line since it keeps that motor or pump running!

HERE IS A NEX FLOW®SOLUTION especially ideal for hot and dirty environments:

We suggest the Nex Flow® Frigid-X® Panel Cooler

They are:

1. Reliable as they do not require electricity to function,
2. Free up Employee Time due to its reliability
3. Essentially Maintenance Free with no filters to change or worry about and even keeps control panels clean by keeping out dirty plant air, and
4. Prevents Downtime due to Overheating by maintaining the proper environment inside a control panel.

Every Panel Cooler comes with a Temperature Indicator sticker that you can put on the outside of a control panel to indicate if the approximate temperature inside the enclosure. Extra stickers can be purchased for other panels. Monitoring does not always need to have a high cost.

 

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.

Industrial Panel Air Conditioning Options and Trends

The various options for cooling electrical cabinet coolers include, traditional compressor-based air conditioners, air-to-air heat exchangers (with heat pipes), thermoelectric air conditioners, and finally vortex coolers. Each cooling method has its plus’s and minus’s.

Sensitive electronic devices are used increasingly in hostile environments. High temperatures, contaminant-laden air, high humidity and corrosive atmospheres are bound to negatively affect sensitive electrical and electronic equipment. Damage to the controls can result in costly repairs, downtime, and even lost data. Inadequate protection of the controls can cause unwanted heat buildup, which can increase an enclosure’s internal temperature above the manufacturer’s recommended ratings for electronics/electrical equipment installed inside. This heat can come from both internal and external sources.

Internal heat sources come from the very components that needs cooling. These include:

• Variable Frequency Drives (VFD’s)/inverters
  
• Battery Pack back-up systems
  
• Communication equipment
  
• PLC systems
  
• Power supplies
  
• Routers & switches
  
• Servers
  
• Transformers

External heat sources come from the factory environment. Including:

• Heat from blast furnaces and foundries in heavy steel and metals production
  
• engine rooms
  
• food processing factories with high humidity and heat
  
• industrial ovens from bakeries and paint facilities
  
• hot climates in general
  
• manufacturing plants, especially producers of materials like insulation, carbon black or where other airborne dust and dirt particles are in the factory atmosphere
  
• outdoor solar heat gain if the control are in direct sunlight
  
• uninsulated and/or non-air conditioned buildings that heat up during the day

Although these heat sources may present a problem and potential damage to the systems – there are various methods in keeping the control panel cool. Here are some ways along with their advantages and drawbacks.

Traditional Compressor-Based Air Conditioners
Pros: High cooling capacity
Cons: Higher maintenance, high capital cost, more sensitive to breakdown the worse the environment

Compressor-Based air conditioners rely on chemical refrigerants to remove heat from electronic/electrical enclosures. In addition to refrigerants, these air conditioners also use compressors, evaporators, condensers, and fans to provide cooling.  The refrigerants used in the past are being replaced with more environmentally friendly products but the cost of these new refrigerants are sometimes ten times that of the obsolete refrigerants. In addition, some if not most of these new refrigerants are flammable which means there are design changes to insure safety when connected to a control panel with a potential to produce a “spark”. These units produce condensate which must be removed.  Fans need filters which must be cleaned or replaced. If mounted on equipment subject to vibration then the refrigerant can leak out prematurely and need costly replacement. This also means more shutdowns affecting production. Depending on the factory environment lifespan of a traditional air conditioner can be anywhere from five to ten years but in very harsh environments, much much less.

Air-to-Air Heat Exchangers
Pros: Low maintenance, relatively inexpensive
Cons: Cannot cool below ambient so limited by environment.

Efficient, cost-effective cooling can be realized through heat pipe assembly systems. These air-to-air heat exchangers remove waste heat from sealed electrical panels and enclosures to protect sensitive electronic components without exposing them to harsh, dirty environments outside the cabinet, a nice advantage.  Simple design means long life as well, although because they use fans, the fans need to have care and maintenance, especially in harsh factory environments. However, the big problem is that you cannot cool below the environment ambient temperature and in many factory environment that temperature is still too high and therefore limiting the use of this technology.  

Thermoelectric Air Conditioners
Pros: Reliable, relatively low maintenance
Cons: Cooling capacity is limited, and must be careful to size accurately, potentially use much more power to operate, extra care needed in installation.

Thermoelectric solid-state air conditioners utilizing the Peltier effect were introduced some years ago but only have limited use for a variety of reasons.  This effect is harnessed by using two elements of a semiconductor constructed from doped bismuth telluride. Upon application of a direct current (DC) power source, the device transfers heat from one side to the other. The side that heat is taken from becomes cold. They can dissipate loads up to 2,500 BTU/hr.  However, there are some issues to consider. Peltier modules release a large amount of heat in the course of operation. They require in the cooler heatsinks and fans capable of efficiently deflecting surplus heat from the cooling modules. Thermoelectric modules are noted for their relatively low efficiency coefficient; when they act as heat pumps, they are powerful sources of heat. Using these modules in cooling devices however, intended to protect the electronic components of the computer, dramatically increases the temperature within the system unit. This sometimes requires additional cooling devices within the controls. If you don’t use additional cooling, the high temperatures can complicate operating conditions — even for the modules. Also, using Peltier modules creates a relatively heavy extra load for the power supply to handle.  At the cooling side, the low temperatures produced by the operation of Peltier coolers can be too low and cause moisture from the air to condense inside the cabinet. This is dangerous for electric components. Therefore extra care needs to be taken in choosing the correct unit. When choosing a Peltier module of appropriate cooling power, it is necessary to ensure that the entire surface of its cold and hot sides are used. Otherwise, the parts of the module that do not have contact with the surface of the protected object (such as a processor chip) will only waste power and emit heat, decreasing overall cooling efficiency, possibly quite dramatically. One comment made by an informed user was that “They only become effective when the temperature differential is large enough. In most cases it will just increase the wattage drawn without doing anything that much better than a plain air conditioner.”   The cold side gets cold, but then you’ve got an even larger amount of heat to remove from the hot side. So you need an even larger heatsink or some heat removal system on the other side. Hence the extra care in any installation.

Vortex Coolers
Pros: Low maintenance, small footprint, low cost, keeps out moisture and dirt, no condensate, not subject to vibration, easy to install.
Cons: Require compressed air

Vortex coolers can be a low cost way to cool and purge electronic/electrical enclosures, especially in situations where conventional cooling by enclosure air conditioners is not possible. Applications may include small to medium size equipment enclosures.  Vortex coolers use compressed air to provide a cooling air flow. This means they are limited to applications where there is a ready source of clean, compressed air such as in medium to large industrial plants. The positive aspect is that it is these sizes of factories that usually have the cooling issues with their electrical and electronic control panels – hot and humid environment, and dirt and particulate in the atmosphere, have the compressed air. 

The primary component in a vortex cooler is a vortex tube, also known as the Ranque-Hilsch vortex tube that creates a swirling effect from the compressed air input and separates it into hot and cold air streams. A vortex cooler is unique in that it has no moving parts. At the end of the hot tube, a small portion of this air exits through a needle valve as hot air exhaust. The cold is pushed into the enclosure which air conditions the cabinet.  A properly designed vortex cooler like the Nex Flow panel Cooler has a built-in exhaust so there is no need to vent the enclosure, and has been tested and NEMA (and/or IP) approved to insure no water can get inside a cabinet from the outside. This vortex provides a positive purge on the cabinet, which also helps to keep dirt, dust and debris out of the enclosure.  There is no condensate to deal with. Because the compressed air is filtered to be clean and moisture removed (a necessary requirement with vortex coolers), even if the compressed air supply is saturated with moisture before the filter, there will be no moisture inside the cabinet because the compressed air goes back to near atmospheric pressure keeping the relative humidity of the cooling air low.  One nice feature about the cooling effect of a vortex tube cooler that is often not noticed is that its cooling effect depends only on the temperature of the compressed air. So even if very hot environments, for example right next to a hot furnace, as long as the compressed air temperature is reasonable, it will cool very effectively.   It is very difficult to install a vortex cooler badly. It is simply a matter of putting in a standard knockout hole on the control panel, installing the unit, adding a hose with punched holes (to distribute the cold air around the panel quickly), and then let it operate. An optional thermostat with solenoid can turn the air on and off as needed to conserve energy.  A major application is for variable frequency drives (VFD’s) where the cooling is normally needed only on startup only so energy use is actually quite minimal and very cost effective.  The harsher the factory environment, the more vortex coolers become economical as they do not break down in such environments nor do they have the extra maintenance the alternatives require.

WP Data Tables

A solution to Refrigerants’ Flammability

Air conditioners are everywhere, in homes, cars, office buildings, and even factories. They are also used to cool small enclosures, in particular electrical and electronic control panels. It is these small enclosures that this article will focus upon. Air conditioners utilizes refrigerant. The original refrigerants were CFC’s or Chlorofluorocarbons which are highly stable compounds that were also used as propellants in spray cans and in refrigeration and air conditioning units.  Unfortunately, due to that stability they were found to deplete the ozone layer and were replaced by hydrochlorofluorocarbons (HCFCs). HCFCs and hydrofluorocarbons (HFCs) that came right after were created as substitutes for CFCs for use in refrigeration and a wide variety of manufacturing processes due to the lower effect on the ozone layer. HFCs have little effect on ozone but contribute to global warming. All of these classes of compounds either destroy the stratospheric ozone essential to life or contribute to global warming, international agreements have been signed to eliminate their production and use by the year 2040.

One of the problems with the new refrigerants is that most are flammable. For example, Flammable refrigerants are illegal to use in an automotive air conditioning systems. There are some exceptions, such as the new  R1234yf refrigerant, which is mildly flammable but only under certain conditions.  Before we focus on air conditioning of electrical and electronic control panels, let’s look at a major small enclosure use and that is in automobiles. Many automobile manufacturers have approved the product.  However, it is notable that initially Daimler, the parent company of Mercedes-Benz originally did not approve the use of the refrigerant especially when a video that was made public of a test showed the interior of a Mercedes hatchback catching fire after R1234yf refrigerant leaked during a company test.  

Credit Wikipedia : https://en.wikipedia.org/wiki/Side_collision#/media/File:Ford_Focus_versus_Ford_Explorer_crash_test_IIHS.jpg

 

A thought to keep in mind is what happens if your vehicle is involved in an accident. The A/C condenser sits right in front of the radiator and contains high pressure refrigerant vapor and liquid. If the condenser is ruptured in a frontal collision (which it often is), high pressure flammable vapor will be released, almost guaranteeing an underhood fire! So presumably re-designs have been implemented to minimize any possibility of a fire in case of an accident.  One possible solution to the flammability issue HFC-152a (or other flammable refrigerants) is to add a leak sensor inside the vehicle that warns the passengers if a leak occurs, and automatically opens the power windows to vent the vapors (thus, reducing the fire/explosion risk). Another solution is to redesign the A/C system so that it uses a “secondary loop” to keep the flammable refrigerant in the engine compartment and out of the passenger compartment. With this approach, the refrigerant circulates through an intermediate heat exchanger and chills a liquid (probably a water/antifreeze mixture) that then flows through the HVAC unit inside the vehicle. A recent report from the U.S. EPA says this approach meets its safety criteria, while also being energy efficient. But it does not reduce the risk of fire in a frontal collision, and it still poses a risk to technicians and do-it-yourselfers while recharging or servicing the A/C system. 

Honeywell developed in mid-2018 a product called Solstice N41 (provisional R-466A), a non-flammable and lower global-warming-potential (GWP) refrigerant for use in stationary air conditioning systems. Once on the market, Solstice N41 will be the lowest GWP, non-flammable, R-410A replacement refrigerant available worldwide.  This is significant and would certainly address the flammability issue. But it still has global warming concerns albeit much less. Daimler and others such as Volkswagen also have opted to use CO2 as a refrigerant instead but CO2 requires high pressure systems and of course, CO2 is a greenhouse gas. But these alternatives do deal with the flammability issues.

After all this, there is a second problem with the new refrigerants – cost.  The cost of the refrigerant itself is multiple times the cost of the old ones being replaced – as much or by a factor of ten times. Then there is a cost of material changes and some redesign of the air conditioners themselves.

Now, let’s change the environment to that of a factory floor in a production setting where air conditioners or cabinet coolers or panel coolers are used to cool electrical and electronic control cabinets. The first question is whether it is safe to have a flammable refrigerant used in a device that will be mounted to an electrical device? Design has to assure that a spark from a faulty control does not cause a fire from potentially leaking refrigerant. The second is cost, due to the high cost of these new refrigerants. Replacing refrigerant could be far more common on a plant floor compared to an automobile due to heavier use and also from vibration that the air conditioner may be subjected to.  If the non-flammable refrigerant is used, or if a CO2 system is used, the cost is still much higher than traditional systems used in the past and cooling systems more complex.

What is certain, is the rising cost of traditional air conditioning systems.  An alternative has existed for years and that is vortex tube cooling systems.  These systems like the Nex Flow Panel Cooler use only compressed air to operate, with no carbon footprint, no flammability concerns, no chemicals to replace and virtually zero maintenance.  Their use does require the facility to have compressed air but this is available in most large manufacturing plants. They are used mostly for control panel air conditioning in harsh environments where maintenance costs even on traditional air conditions offsetting the maintenance costs.  With the new refrigerants coming into play, and with their extra costs for refrigerants, and most costly air conditioning assemblies, the very simple design of the vortex tube operated air conditioners become more economical. In addition new vortex tube panel cooler designs are being developed to improve their efficiency and more efficient air compressors are also being offered.   So while at the traditional air conditioning end capital costs go up, the operating costs of vortex tube operated systems is trending downward.

Developments in new refrigerants should be carefully watched as it affects all of us concerning the environment and its impact of manufacturing operations and all other areas where they are used.  But at least for manufacturing, there is a potentially better alternative with vortex tube operated systems like the Nex Flow Panel Cooler.

How can panel coolers prevent factory downtime?

Electrical and electronic control panels are the heart of factory production.  Any problems that occur with them can cause minor to major production hiccups, slow downs and potential need for a factory shut down.  Just as you would take care of your own heart, it only makes sense that you recognize the heart of production and take good care of it.

But often this does not happen.  How many times do you see control panel doors left open because they get “hot” inside. This creates a potential safety hazard and if the environment is not clean, it may cause dirt buildup inside the panels, on the controls – eventually leading to potential costly, premature failure.

As often as not, these control panels that are left open due to heat buildup is because of a lack of maintenance on whatever cooling system they may already have. It could be a simple external fans, external blowers, or traditional panel air conditioners. Even with water cooled systems, maintenance is necessary. External fans need filters, especially in dirty environments and these filters get dirty and require regular cleaning and/or replacement.  Similarly with blowers, perhaps even more often. Water cooled systems have small water lines and can scale up, preventing adequate cooling. Traditional air conditions are an even more critical machines for regular maintenance. Not only do filters need to be cleaned and/or changed regularly, especially in dirty environments, if air conditioners are on machines that have vibration the refrigerant inside may leak out the unit. It is important to recognize the cost of the smallest downtime due to a control panel “going down”.

So what can be done?  If whatever cooling system is working well and you do not have issues with control panels overheating, then of course nothing.  Keep doing what you are doing. But if you have even once have to open a cabinet door to vent out some heat – then you have a problem.  Would you ignore a sharp pain in your own heart? Well, that overheating is the panel’s pain.  

One solution is to overhaul the maintenance program on the control panels as that can certainly be a source of the problem but that in itself may reveal and create other costs. But it is one option.  Another option is to use a Nex Flow Panel Cooler.

Despite the use of compressed air for operation the Nex Flow Panel Cooler is essentially maintenance free.  Once installed, it can be left to operate under the worst conditions of a dirty factory environment, with high humidity, high ambient temperature and even on equipment that vibrates. How it works is simple – compressed air enters the Nex Flow Panel Cooler and the vortex tube component separates the compressed air into a hot and cold stream.  The hot end is exhausted as waste but the cold air goes inside the control panel to cool and keep the cabinet from overheating. The connection to the cabinet has a built in exhaust to vent out the hot air displaced by the cold air. Since there are no moving parts, and no refrigerant chemical inside the unit, the Panel Cooler can handle equipment vibration.  The air entering the cabinet keeps the cabinet at a slightly positive pressure keeping out any humidity and any dirt and particulate in the environment. The effectiveness of the air conditioning depends solely on the temperature of the compressed air and not the environment making Panel Coolers ideal to use in hot and humid locations. There is no condensate produced that needs to be disposed of and you do not have to worry about replacing filters. The only basic requirement is to properly filter the supplied compressed air.  To conserve energy, a thermostat and solenoid valve control system can turn the air on and off as required.  Alternatively an electronic thermostat system can be used.  To keep the cabinet constantly at positive pressure to keep out a very nasty environment, a bypass system can be installed around the solenoid to always have a very small amount of compressed air flowing even when the unit is off.

If maintenance is not adequate or perhaps the environment is just so unfriendly it causes serious and costly issues for whatever the reason for problems with traditional air conditioning or other cooling systems, the Nex Flow Panel Cooler can be a viable option and the extra energy costs often offset by the shorter life span, or damage to controls and other problems created using other systems.

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:

1. Anodized aluminum parts
2. Powder coated parts
3. No Plastic in our vortex tubes
4. 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.

When Should I Consider Using Vortex Tubes for Spot Cooling?

Vortex tubes create a stream of cold air from compressed air.  When discussing spot cooling we want to specify that it is a “small spot”, and not a large area such as would be addressed by a big fan for example.  We want to focus on a small area from a tiny “spot” to a few square inches, or to an enclosure which can be much larger to a maximum of around 10 square meters, although there are exceptions.

Such “spot cooling” is needed when heat at that spot is either causing a problem in production or, if production can be improved by cooling. The most common “enclosure cooling” is the cooling of electrical and electronic control cabinets that have potential overheating issues and/or where there are dirt problems due to an unfriendly factory atmosphere inside the enclosure negatively affecting performance and potentially the life of the electrical equipment.

One major “spot cooling” application is the cooling of cutting tools during cutting, drilling, or routing process.  Traditionally cutting fluid is used in machining but there is a slow but steady movement to “dry” or “near dry” machining because of the increased safety and especially environmental concerns involved with cutting fluids. Cutting fluids need to be properly disposed of, so there are costs of not only buying the fluid but also the disposal of the fluid.  One of the reasons progress is somewhat slow in adapting to dry machining is that cutting fluid not only cools, but also lubricates and cleans the machine tool as it operates. This is where mist cooling systems can come in handy because it is not completely dry allowing lubrication but limits the need for cutting fluid. That being said, dry machining is actually necessary for some materials such as glass, plastic, ceramic and titanium. Vortex Tubes produce the cold air which is blown onto the cutting tool to keep heat down and actually produce a better cut and speed up the machining operation.  Often these vortex tubes are packaged with an easy to mount system such as the Nex Flow Tool Cooler. 

In some machining application, as when a hole must be drilled deep into a part, some lubrication is required.  Nex Flow developed the patented Mist Cooler to provide the necessary lubrication by misting lubricant “cooled” by the vortex tube.

There are of course many other systems developed and being developed to spot cool for machining and eliminate coolant using inert gas for example but the vortex tube is also an integral part in many of developments because they only use “air” and cost in comparison is usually much lower.  Cooling gas samples in gas analyzers is another good application for vortex tubes. Industrial camera and all sorts of sensors are used in production more and more, and many of these devices are in very hot areas on a production line. Vortex tubes are compact enough to be used to cool these products and keep them functioning effectively and with no maintenance compared to any other alternative.

Other spot cooling applications addressed by vortex tube technology are numerous and limited only by imagination. Some applications for vortex tubes include cooling the nip roll in a plastic converting process for example to prevent sticking, cooling the head of lasers to prevent heat buildup, setting hot melt adhesives so the glue dries faster and to maximize throughput.

Alternatives in such applications can be much larger in size but vortex tubes are very small. Larger size also typically  translates into larger capital cost. As vortex tubes have no moving parts, their maintenance is virtually zero and as long as the compressed air is filtered, their life is as long, or even longer than the equipment they are used with. Compact, zero maintenance and low cost are the key advantages of using vortex tubes for spot cooling over other alternatives.

Utilizing vortex tube technology for cooling enclosures is another major application.  There are many ways to cool electronic enclosures and other enclosures with traditional air conditioners.  However, factory environments can range from quite benevolent to very harsh. A carbon producing facility will be very dusty.  This dust can easily get into control cabinets and cause havoc to the electrical components inside. The limitation on the use of vortex tubes is the amount of compressed air available in any facility.  The cost is also a major consideration as compressed air is costly. Where vortex tube based products such as the Nex Flow Panel Cooler become an advantage is when the increased energy cost offsets the cost savings in equipment maintenance costs in both material and time, and in offsetting damage to the controls.  It is for very hot, humid or harsh factory environments, that increased energy cost of vortex tube cooling systems can be offset by the savings in maintenance time, materials, disposal of filters and improved control life because they keep out the nasty environment from the cabinet enclosures.

Vortex tube controlled cabinet coolers, like the Nex Flow Panel Cooler, have proper electrical certification to assure that no moisture can enter the cabinet. For example, the Nex Flow Panel Cooler models are available to mount onto cabinets with NEMA 12 (IP 54), NEMA 3R (IP 14) and NEMA 4X (IP 66) classifications.

Vortex tubes for these small “spot” and such “enclosure” applications are both a cost-effective and simple solution where cooling is required.

Vortex tubes are ideal for spot cooling and enclosure cooling.  Typically one vortex tube is used for one “spot” and for “one” enclosure.  But there are some situations where one vortex tube can be split into multiple “spots” as long as one important criteria is kept in mind.  Once the compressed air exits the vortex tube it needs to be directed to the area that needs the cooling.  When the vortex tube is out in the open, this is achieved by adding a delivery tube, usually flexible tubing to direct the cold air to that spot.  When cooling an enclosure, the cold air is sent directly into the enclosure from inside the enclosure. Once the air exits inside the enclosure it can be further distributed around the enclosure thru tubing but all the cold air is input into the enclosure.

Two factors that must be considered when using the cold air produced in a vortex tube: conduction and pressure drop.  The general rule it to keep any tubing on an open space vortex tube as short as possible, preferably under 8 inches. One example where a vortex tube has been used in open space for multiple locations is on routing a plastic part.   Once Nex Flow Model 50030H vortex tube had the cold air split into two directions and delivered to cool two routers. Rather than using one vortex tube for each router, one larger capacity vortex tube was utilized. If two separate units were used, they could have been smaller capacity units (Model 50015H), each which is ½ the capacity of what was used.    What made this work was delivering the air with large (10 mm) tubing to offset pressure drop and keeping the distance as short as possible (under 8 inches to each router). Also, the tubing was insulated to minimize the effect of conducting heat from the surroundings into the tubing, heating up the cold air. There was consideration for using two vortex tubes but there were also space issues with the application.

But this is not a common application.  If the distance they had to cool was much longer from the vortex tube, we would have recommended two of the smaller capacity vortex tubes.  There is another consideration when considering the use of vortex tubes for multiple location cooling. Let’s take the example above. If the distance from the vortex tube was only a few inches more, to get the same cooling effect at the router, we would have had to use a larger capacity vortex tube, a Model 50040H.  That extra 10 SCFM of compressed air use costs energy. That extra energy cost would more than pay for the extra vortex tube in a very short time, and even if used sparingly, certainly in under a year. The increased operating cost, even with minimal use, can easily be equal to or more than the capital cost of one additional unit.

Concerning enclosures, more than once we had to address an issue with cooling when a Nex Flow Panel Cooler, instead of being attached directly to the control panel. Was for some reason mounting off to one side, and a tube was attached to the bottom of the Panel Cooler and then put into the control panel.   Needless to say, the unit did not cool as was expected because the cold air heated up several degrees before it reached the control panel. The Panel Cooler has a built in vent to exhaust the displaced hot air inside the cabinet and of course was not used at all when mounted outside. If you are facing any difficulties with installation – please do not hesitate to contact one of our engineers.

Another thing to remember when installing a vortex tube or a vortex tube operated device like the Panel Cooler, onto an enclosure that it must be installed at the top, or if space is lacking, near the top using a side mount.  The reason is that cold air falls and hot air rises. The reason a distribution tube is used at the end of a Panel Cooler is to distribute the cold air faster to isothermalize the cabinet (even out the temperature) more quickly.  If the vortex tube device is mounted too low, the hot air will tend to stratify at the top of the inside of the enclosure.  

When considering any vortex tube operated device – cabinet enclosure cooler, tool cooler, spot cooler, mini cooler or the vortex tube itself, it is best to keep any attachment at the cold end as short as possible when the product is in open space.  When attached to an enclosure of any type, the cold air should be directed directly into the enclosure, near or at the top.

Choosing the best Spot Cooler

What are Spot coolers and their Importance?

Spot coolers are self-contained air conditioning systems that have all the components of larger air conditioning systems but are compact and easy to move.  Spot cooling for industrial applications are used short term to cool a small area on a part or in an enclosure – such as a cabinet. Spot coolers are ideal for cooling electronics, computer server rooms, and humans in small confined work environments. They are often praised for their portability, ease of use, and installation.

Fans cannot cool below ambient temperature because they cool by moving air and cool a wider area.  Compressed air amplifiers cool better than fans because of the higher velocity but they also do not cool below ambient temperatures. Air amplifiers also cool a wider area. This blog discusses the three most popular ways to cool below ambient temperature, namely Vortex Tubes, thermoelectric, and cryogenic gas (CO2 and Nitrogen Gas) cooling systems.

It is important that the spot cooling system chosen is reliable because sudden or frequent break downs can cause costly equipment damage, repair, or replacement.  Keeping humans cool in a small work area is important as well for health and safety concerns. All Spot coolers come with accessories that allow you to direct the cooled air where it is needed most.  Any condensation that results from the cooling process is drained through a hose or bucket.  

 

Vortex Tube Cooling System

Vortex Tube Cooling systems are powered by compressed air. The vortex action separates the compressed air into extremely cold and hot streams.  The cylindrical form causes the compressed air to rotate at a high speed (reaching 1 million rpm). A small portion of the air exits through a needle valve as hot exhaust. The remaining air is forced through the center of the incoming air stream at a slower speed. The action of the slower moving air dissipates any remaining heat into the faster moving air. The super-cooled air flows through the center of the generator and exits the cold air exhaust. Depending on the temperature and pressure of the incoming compressed air, it is possible to achieve cold end temperatures as low as – 40 and even – 50 degrees F.  The hot air (end) can be up to 260° F (127° C).  The Vortex cooling system, or cold end of the Vortex Tube, is often used for “spot cooling” of cabinets, such as control panels and industrial cameras.

Vortex Tubes normally come with the “hot end” adjustable to control the flow and temperature out the cold end.  The more flow out the hot side, the lower the temperature out the cold side.  The cooling effect (BTU/hour) is determined by both flow and temperature drop. Therefore, for cooling applications, the cold end should be between 60% – 80%.  If the cold temperature is most important, then the flow out the cold end should be under 50%.

Choosing the best Spot Cooler

Factors in selection:

Vortex Tube cooling systems that use compressed air is considered where conventional enclosure cooling by air conditioners or heat exchangers is not possible. Ideally, Vortex Tube cooling systems are used to cool small to medium size enclosures, nonmetallic enclosures, and areas where the size of cooling devices is restricted. 

For optimum cooling results when using a Vortex Tube cooling system, the following items are required when installing:

• Clean, dry, oil-free compressed air 
• 80 to 100 PSIG / 70 degrees F or below. Lower pressures and higher temperatures will reduce BTU/H ratings.
• A 5-micron water and particulate removal 
• A 5-micron oil removal filter when oil is present
• Thermostats or temperature indicator sticker
• Valve (optional)
• Muffler go minimize exhaust noise

 

Advantages:

The Vortex Tube cooling system has many advantages. The small, portable, light weight, and compact system creates extremely cold air without refrigerants, included CFCs or HCFCs.  It is exceptionally reliable since there are no moving parts and virtually maintenance free. It uses minimal electricity (only for the compressor). Vortex Tube cooling systems are useful in harsh and high temperature environments. Customers can expect a long life from Vortex Tubes because Nex Flow uses only Stainless-Steel with a brass generator. Compressed air is not the only gas that can be used to produce cold air, Nitrogen and other natural gases that can be compressed can be used as well.

 

Applications:

Vortex Tube cooling systems can be used to cool:

• electronic and electrical control instruments
• machine operations/tooling
• CCTV cameras
• Set hot melt adhesives
• soldered parts
• gas samples
• heat seals
• environmental chambers
• workers wearing protective gear
• data centers
• plastic machined parts and molded plastics
• Electronic components

It is understood that cold and hot gas (bi-product) is generated when using a Vortex Tube cooling system.

Choosing the best Spot Cooler

Thermoelectric Coolers (Peltier Effect)

Thermoelectric cooling (TEC) became a viable option for spot cooling in the late 1950s with the development of semiconductor materials. The thermoelectric cooler (TEC), often called the Peltier module, is named after Jean Peltier who discovered heating/cooling effect when passing electric current through the junction of two conductors in the early 1800s. It is a semiconductor-based electronic component that functions as a small heat pump.

Using a low-voltage positive DC voltage to a TEC, electrons pass from one element (p-type) to another (n-type), and the cold-side temperature decreases as the electron current absorbs heat, until equilibrium is reached. The cooling is proportional to the current and the number of thermoelectric couples. This heat is transferred to the hot side of the cooler, where it is dissipated into the heat sink and surrounding environment. The result is a quick and large temperature differential.

 

Factors in Selection:

To use Thermoelectric spot cooling, a DC voltage required. This type of spot cooling is ideal when refrigerants are not desired, and space is limited.  It a cost effective, reliable, efficient way to spot cool. Multiple thermoelectric coolers are connected side by side and then placed between two metal plates.  It is ideal for intermittent heating and cooling applications because TEC seamlessly switches between heating and cooling.

 

Advantages:

Thermoelectric spot cooling has come to dominate certain applications because of the following benefits:

• Precise temperature control and stabilization to 0.01 degree C
• reliable
• noise-free operation
• vibration-free operation
• scalable 
• compact

Choosing the best Spot Cooler

Applications:

TEC is used for spot cooling for the following applications:

• Telecommunication applications:
  • 980nm and 1480nm Pump Lasers
  • Digital Transmission Lasers
  • Planar Lightwave Circuits
  • Optical Channel Monitors
  • CATV Transmission Lasers
  • Avalanche Photodiodes
  • Wavelength Lockers
• Medical samples
• Cold storage
• Electronic cabinets
• Self-powered appliances
• Small scale refrigeration
• Harsh environmental protection for critical components
• Computer microprocessors and robotics
• Cabinet cooling

 

Cryogenic Cooling (Carbon Dioxide or Nitrogen gas)

Cryogenics is the scientific study of materials and their behaviors at temperatures well below conventional refrigeration.  The word comes from the Greek cryo “cold” and “genic”, which means “producing”. Cryogenic temperature ranges can be reported using any temperature scale, but Kelvin and Rankine scales are most commonly used because they are absolute scales that have only positive numbers.  The U.S. National Institute of Standards and Technology (NIST) considers cryogenics to include temperatures below −180 °C (93.15 K; −292.00 °F), which is a temperature above which common refrigerants (e.g., hydrogen sulfide, freon) are gases and below which “permanent gases” (e.g., air, nitrogen, oxygen, neon, hydrogen, helium) are liquids. At 250 F below zero, many gases are liquid.  Below is a list of temperatures where these gases boil. 

Fluid	Boiling (Celsius)	Boiling (Fahrenheit)
Oxygen	-183°	-297°
Nitrogen	-196°	-320°
Neon	-246°	-411°
Hydrogen	-253°	-423°
Helium	-270°	-452°

Before the fluid’s temperature rise, all the liquid must boil away and turn into a gas. None of these gases exist naturally as a liquid. Each of the gases are cooled to put them into a liquid state.

Latent heat absorption during the phase change from solid to liquid or liquid to gas causes cooling in the immediate area. According to the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), liquid CO2 (LCO2), known as Refrigerant R-744, is the most widely used method used during vaporization of a liquid to a gas. When liquid CO2 is introduced to the system through the nozzle of a spray gun or cooling injector tube on a temperature chamber or thermal platform (cold plate), the liquid quickly turns to solid state CO2 or dry ice. As the dry ice warms up or sublimates (direct change from solid to gas), a great release of the latent heat occurs.

 

Liquid CO2:

Spot-cooling method uses liquid CO2 injected in controlled pulses through tiny capillary tubes inserted into hard-to-cool areas to the same level as the rest of plastic mold cores. This approach is meant to complement conventional water cooling by ensuring uniform mold temperature without hot spots. 

When the cooling cycle begins, LCO2 is fed under high pressure (approximately 850 psi (58.6 bar)) through the thin, flexible stainless-steel capillary tubes with solenoid valves to time injections and to the points where cooling is required. The high sublimation energy of the CO2 from solid to gas phase, along with the resulting cold gas, provides a very high local cooling capacity. The CO2 withdraws heat from the steel of the mold and escapes out of the expansion room in gaseous form through an annular gap between the hole and capillary tube. 

 

Liquid Nitrogen:

Under normal atmospheric pressure, Nitrogen can exist as a liquid between the temperatures of 63 K and 77.2 K (-346°F and -320.44°F). Below 63 K, nitrogen freezes and becomes a solid. Above 77.2 K, nitrogen boils and becomes a gas.  Since it is obtained from the atmosphere, liquid nitrogen is inexpensive and is rarely refrigerated. It is kept in insulated containers called Dewars and can boil away. 

 

Advantages:

Given the purity of LCO2 supplied for this application (typically >99.98%), there is little danger of residue build-up or contamination of the hole as there would be with water cooling.  Meanwhile, Liquid Nitrogen is colorless, odorless, and tasteless. It is an Inert element that is noncorrosive and does not support combustion, so it is safe.

 

Disadvantages:

There are several risks involved in cooling using cryogenic cooling systems. There is always a risk of asphyxiation, frostbite, or burns if not used and handled properly.  Cryogenic gas has large expansion ratio for evaporation. For example, if one liter of liquid nitrogen can result in 700 liters of gas. If released in a small room, it can fill a room and make it an oxygen deficient atmosphere. It is also not safe to digest. It is essential that all the liquid nitrogen is evaporated before ingested otherwise it can boil and cause damage to internal organs.

Choosing the best Spot Cooler

Factors in Selection:

Cryogenic spot cooling systems are ideal for specific applications in automotive, medical, aerospace, consumer products, plumbing, and construction.  CO2 is the preferred coolant for spot cooling because it is cheap to capture and compress. It is also ideal for large scale applications due to lower volume cost and longer storage times. The cooling requirements should be above -50 C. For repeated cooling, CO2 must be supplied at the right pressure and at the right temperature without gas bubbles. It stores longer than liquid nitrogen gas, which is stored at -190 C.  

Liquid Nitrogen cryogenics is colder and has greater heat removing capabilities below -60˚C. Proper supply and control system design is crucial because if too much coolant sublimates to a solid state at once, blockages in the cooling system can occur.

It is highly recommended that oxygen monitoring equipment is used to test for oxygen deficient atmospheres during cryogenic spot cooling. The system must be properly maintained to prevent blockages. 

 

Applications:

Applications of cryogenic spot cooling include:

• Cooling of construction mold
• Preserve experimental samples
• Coolant for computers
• Medicine to removed unwanted skin, warts, and pre-cancerous cells
• Instantly freeze food and cocktails – creating an impressive cloud of vapor or fog when exposed to air. 
• Internet searches will find recipes for nitro-caramel popcorn and pumpkin-pie ice-cream
• Plastic and rubber deflashing and grinding
• Metal treating
• Biological sample preservation
• Pulverization

 

Summary

Vortex Tube cooling system is a low-cost choice for industrial applications. Simply adjust the hot end hot air valve to determine the temperature at the cold end. The more air escaping from the hot end reduces the temperature of the cold air flowing from the other end of the Vortex Tube. 

It produces cold air instantly for enclosed environments.  Since there are no moving parts, there is no spark or explosion hazard.  Vortex Tube cooling system have two types of generators that are easily interchangeable. One generator has a cooling effect while the other one restricts the flow of the cold air, which creates extreme cold temperatures such as -40 or -50 F. Apart from special designs, the technology is available in the following configurations:

• Packaged Frigid-X® Panel Cooler for cooling control panels
• Packaged as an adjustable spot cooler
• Packaged as a tool cooler or mini cooler
• Packaged as a mist cooler

When you need require extreme cold temperatures, Nex Flow recommends using the Frigid-X® 50000C series. Nex flow vortex tub cooling system consists of a stainless-steel body with all metal parts.   The cooling system is quiet and instantly creates sub-zero cold air temperatures from an ordinary compressed air supply for spot air cooling applications where precise adjustability of temperatures is important.

Like the Vortex Tube cooling system, Thermoelectric spot cooling is an ideal choice for intermittent cooling/heating applications.  The disadvantage is that TEC requires a DC voltage because multiple thermoelectric coolers are connected side by side and then placed between two metal plates. Although equally effective for cooling to extreme temperatures as Vortex Tube or thermoelectric cooling systems for many industrial applications, cryogenic cooling appears to have the highest risks and the greatest need for monitoring equipment for health and safety concerns.

Nex Flow specializes in research and development of cooling technology required for industrial fic applications, such as spot cooling.  Nex Flow® stays ahead of the competition by finding new applications for this unique technology, and to improve the efficiency of the products which depends on many proprietary factors. Corrosion-resistant, food-grade stainless steel means that all Nex Flow equipment is dependable, and long lasting.   All spot cooling equipment is precision machined, assembled, and tested. Manufactured to withstand extreme temperatures and environmental conditions, the Vortex Tube cooling system is produced under strict quality control, which ensures years of reliable maintenance free operation.

Vortex tubes are devices that take compressed air and spins it inside the unit creating a spinning air flow in one direction and spins the air flow back in the opposite direction within the first spinning air flow. Part of the air flow is out one end and gets hot, and the internal spinning flow that is let out the opposite end gets cold. It basically acts like tube in tube heat exchanger.

Air input the vortex tube is normally 80 to 100 PSIG (5.5 to 6.2 bar). The air exiting at each end of the vortex tube goes back to atmospheric or at least to a much lower pressure.  In considering what you can or cannot attach to vortex tube, you must first consider these realities:

1. You need a pressure difference between the inlet air to the unit, and the exit points.  If there is no significant difference then the system will not work.
2. The percentage of the air out the cold end is called the cold fraction. For example, if 80% of the inlet air exits the cold side the cold fraction is 80% and the hot fraction (air out the hot side) is 100-80 = 20%.  If you add anything to the cold end, there will be a back pressure. This will affect the cold fraction by pushing more air out the hot side thereby reducing the cold fraction. So there is a practical limit of how much back pressure can be tolerated by attaching anything to the cold end. The ultimate limit is a back pressure that pushes all, or almost all the air out the hot end negating any effectiveness for cooling.
3. Similarly if you attach something to the hot end there will be back pressure pushing more air out the cold end.  The limit would be if all the air is pushed out the cold end – it negates most or all of the cooling effect.
4. Because compressed air exit at both ends, and at a pressure close to atmospheric pressure, a vortex tube is intrinsically safe from over pressurizing, the ultimate supply pressure limited to material integrity (in the case of Nex FlowTM made products, to 250 PSIG).

So when attaching any other accessory to the vortex tube the concepts above need to be considered.  Rarely is any attachment made to the hot air exhaust end except for muffling accessories with minimal back pressure. Even in pre-packaged vortex tubes such as Tool Coolers or Panel Coolers, back pressure is very minimal and typically balanced at the cold end with other attachments such as hose hits or air distribution hose with similar back pressure effects, essentially balancing the system. However, if you examine more closely the cold end attachments, which tend to vary the most, there is a limit there as well. When attaching a hose kit such as locline or similar type of hose, the longer the length the more the back pressure.  Locline hose is used extensively with Tool Coolers. The general rule is to limit the locline to 12” and under and to make sure the opening nozzle has at least a 1/8” opening.  This keeps the back pressure low. Also, the longer you make this attachment, the air will tend to warm up more because of the conduction of atmospheric temperature through the plastic hose to the inside. So practically, the longer the hose, the higher the temperature (less cold air) exiting. In the case of a control Panel Cooler, there is a hose distribution kit supplied which is basically a long PVC hose with a muffler to attach to the end.  Instructions stipulate to create inside this long hose to have at minimum of four (4) holes of 1/8” diameter drilled into the hose to let the air out and blow the cold air from the vortex tube onto the hot parts inside the cabinet. This accelerates the cooling of the inside of a control panel.  Again, the minimum number of holes is required to minimize the back pressure (and also to help iso-thermalize the control panel faster). If the holes are not drilled, the cold air will exit only at the exit of hose end and with the added back pressure will restrict the flow, hence negatively affect the overall cooling rate (slows the process of equalizing the cabinet temperature). The hose addition onto a Panel Cooler also acts as a backup in case of a very remote possibility of any moisture getting into the panel in the very rare case that the filter on the inlet air fails. There are instances where a vortex tube has a hose attached to the cold end to deliver cold air at a long distance for other applications.  It is important to simply use a larger inside diameter hose, the longer the length to minimize back pressure and if possible insulate the hose from conducting heat into the hose, warming up the cold air travelling inside. Care should be taken that the cold end hose is not fully plugged because while the back pressure will force air back out the hot side, any weakness in the hose may also cause it to split and may be dangerous as a result.

The question frequently arise is if it is possible to attach a vortex tube cold air output to the inlet to a blow-off accessory like air knife or an air amplifier (or any other air amplifying or conveying device).   The answer is – it cannot be done simply because of the back pressure requirement of the vortex tube (#3 above). Any air amplifying device requires the air inlet to have high pressure.  For a vortex tube to work, the air exit pressure from the vortex tube must be low.  So attaching a vortex tube to the air amplifying product will just not work.

But…. the possibility of an alternative approach does come up.  There have been a few attempted applications, where the air exiting the cold end of a vortex tube is placed near the air entraining end of an air amplifier such as an air jet or small air amplifier like an FX10, or FX20 or even an FX40.    Successful results are rare however, and not confirmed, due to how air amplification technology works. The air drawn in by an air amplifier is depends on the amplifier size. For example, an FX10 will amplify air flow about 6.5 times and consumes 4.9 SCFM at 80 PSG.  That means it will draw in a volume of 27 SCFM. (6.5-1 = 5.5 multiplied by 4.9). So if you place a vortex tube cold end “close” to the air entraining end the amplified air can be cooled. Even then, much of that cold air will already be mixed with warmer atmospheric air reducing the cold temperature.  And, at the outlet of the amplifier about another 3 times the air is entrained from the warmer atmosphere. Assuming basic adiabatic mixing the cooling effect of the vortex tube supplied air will be greatly reduced. With a larger amplifier, the overwhelming effect of the high volume of entraining atmospheric air overwhelms cooling effect of the small volume of cold air from the vortex tube. This is why mixing the two technologies rarely works.

Air amplifiers and even air knives themselves do cool however, and are used extensively (especially air amplifiers) to cool very hot materials such as castings using the wind chill effect.  It’s like driving with the window down in your car while driving on a hot day. The high velocity of the amplified air will accelerate the cooling of the hot surface because the high flow and high velocity of the amplified air cuts through the heat boundary layer on the part to remove the heat fast.  One example was from an application in Mexico where small, hot aluminum parts which normally cooled in 30 minutes from sitting on a table were cooled in under a minute using a flow amplifier alone.

Vortex tubes are designed to cool enclosures or for spot cooling and not for cooling large areas.  In those applications you are best off using air amplifiers. Therefore, combining vortex tubes with air amplifiers however is not a proven method. When using vortex tubes – it is important to understand the above 4 facts governing the operation of the technology.

How was the first Vortex tube Created?

What is a Vortex tube?

The Vortex tube is a mechanical device that separates compressed gas into two extreme temperature air currents.  It was initially named the Ranque-Hilsch Vortex tube, after the names of the two initial inventors. It is also known by other names including: Ranque tube, Hilsch tube, or Ranque-Hilsch tube. The description of this device was originally described in the US. Patent No. 1952281 by Ranque Georges Joseph. A second US. Patent No. 3173273A was filed by Charles D. Fulton.

According to Charles Fulton US patent – it is defined as an “apparatus for cooling a fluid flowing continuously therethrough comprising a housing body having an opening for admitting a gas, a vortex generator supported in said body and receiving said gas, said generator having a plurality of nozzles and a circular vortex cavity into which said nozzles discharge said gas tangentially, a seal at one end of said vortex cavity, a discharge line communicating with the other end of said vortex cavity, and a smaller line for receiving said fluid to be cooled passing coaxially through said discharge line, vortex cavity and seal.”

Using fluid dynamic principles and compressed air, the Vortex tube generates gas at very cold and very hot temperatures simultaneously. Compressed air is fed into a compact T-shaped tube with pipes attached to each side. With a simple internal generator, the gas emerging from the “hot” end can reach temperatures of 200 °C (392 °F), and the gas emerging from the “cold end” can reach −50 °C (−58 °F).  The owners of this device enjoy an extremely long life with very few issues since the compact device has no moving parts. With the simplistic design and parts, the cost to manufacture and maintain the unit is low. There is also no danger of electrocution or fire. The volume of desired gas flow determines the size of the pipe manufactured. It can be used on any type of gas with consistent results. It is the best, simplest, and most direct method to produce hot and cold air.

The exceptional benefit of the Vortex tube is how little gas pressure is required to produce a large temperature difference in the gas streams.

The requirements for the Vortex tube are:

• Compressed Dry gas (otherwise condensation and freezing of moisture needs to be considered)
• Insulated tube

 

How Does it Work?

Pressurized gas is injected loosely into a swirl chamber and accelerated to a high rate of rotation. With the tapered shaped nozzle, only the outer shell of the compressed gas can escape at that end. The remainder of the gas is forced to return in an inner vortex of reduced diameter within the outer vortex.

The Vortex tube was first explained by observing the geometrical shape and design of the tube and air flow (turbulence, acoustic phenomena, pressure fields). The Vortex tube effect of the compressed gas motion results from the law of energy conservation. The main physical phenomenon of the Vortex tube is the temperature separation between the cold vortex core and the warm vortex margin. It is best described in several steps:

1. The incoming gas is cooled with adiabatic expansion turning any heat into rotational kinetic energy. The total enthalpy is conserved.
   Example of adiabatic expansion is when air rises to the atmosphere and expand due to decreased atmospheric pressure allowing the parcel of air to cool.
2. The peripheral rotating gas moves toward the hot end. Here the heat recuperation effect transfers the heat from the cold slower moving axial flow to the fast moving hot peripheral flow.
3. The kinetic energy from the rotating air turns into heat by means of viscous dissipation. As total enthalpy increases from the heat recuperation process – the temperature is raised compared to the inlet gas.
4. ome hot gas is exhausted carrying with it excess heat.
5. The rest of the gas is funneled toward the cold outlet where more heat is transferred to the peripheric flow. Although the temperature at the axis and at the periphery is about the same everywhere, the rotation is slower at the axis, so the total enthalpy is lower as well.
6. This lower total enthalpy gas is “cold” and leaves the cold outlet.

(https://en.wikipedia.org/wiki/Vortex_tube, Retrieved March 8, 2019)

The vortex cooling is due to angular propulsion.  As the gas moving towards the center gets colder, the marginal gas in the passage is “getting faster”. The more the gas cools by reaching the center, the more rotational energy it delivered to the vortex and thus the vortex rotates even faster.

Compressed gas at room temperature expands to gain speed through a nozzle. It climbs the centrifugal barrier of rotation during which energy is also lost. That energy is delivered to the vortex, which speeds up the rotating air even more. In a Vortex tube, the cylindrical surrounding wall confines the flow at margins and thus forces conversion of kinetic into internal energy, which produces hot air at the hot exit.

The limiting factor for producing the extreme temperatures is high gas pressure to create the extreme temperature changes in the tube.

Who Invented and Improved the Vortex tube?

Georges-Joseph Ranque (7 February 1898 – 15 January 1973) was the inventor of the Ranque-Hilsch Vortex tube. He was born in France in 1898.  At a young age, Georges became interested in physics. In Paris, he studied physics at the Ecole Polytechnique. Afterwards, he pursued a postgraduate degree at the Conservatoire des arts-et-métiers. His initial interest in the operation of the Pantone carburetor led him to study vortices. One of the applications he used the vortex effect was a vacuum pump. His intention was to use his invention to remove dust from a steel plant.  While studying the flow of air through a pump, he inserted a cone at one end of the tube, where air was flowing in a vortex and discovered that the stream of air could be split: one hot and the other cold.  In 1931, he filed the US. Patent No. 1952281.

wikipedia: Georges-Joseph Ranque (7 February 1898 – 15 January 1973)

 

Ranque described his tube as having a counter flow and a uniflow type. Through his research he determined that the counter flow tube was more efficient. The counter flow Vortex tube consisted of:

• A long slender tube with a diaphragm closing at one end of the tube and a small hole in the center of the diaphragm.
• One or more tangential nozzles piercing the tube inside the diaphragm
• A throttle valve at the far end of the slender tube.

On the other hand, the uni-flow Vortex tube is similar in structure to the counter-flow Vortex tube, the significant difference is that the uni-flow tube has two exit holes in the same end. This tube appears to have lower efficiency than the counter-flow tube because of the mix of cold and hot temperature flows at the same exit. Since Ranque’s discovery, the Vortex tube has been the subject of much research and study by the scientific community. The primary focus of research was to determine the factors that caused the thermal separation and to improve the performance of the tube.

Ranque saw the commercial potential of the tube he called “Vortex tube“, which means “tube tourbillion” in French. Unfortunately, compressed air systems were not reliable at the time of this invention. The initial Vortex tube was a commercial failure and Ranque’s firm closed a few years afterwards. He continued to work on other fields of research and the initial discovery of the Vortex tube slowly faded.

The Vortex tube would have remained forgotten if it was not for Rudolf Hilsch, a German physicist, professor, and manager of the Physics Institute of George August University of Göttingen, who is credited with improving the understanding and performance capabilities of the Vortex tube. The important research reported in his 1947 paper, Die Expansion von Gasen im Zentrifugalfeld als Kälteprozeß, emphasized that considerable cooling can be achieved by using the Vortex tube in various applications including refrigeration and cryogenics.  He cited Ranque’s work in the paper but because of a printing error in the footnote, it was difficult for other scientific researchers to locate the previous research. Therefore, the Vortex tube was briefly known as the Hilsch tube. Now, the importance of this paper allowed Hilsch’s name to be included in the name of the tube so that it is now known as the Ranque-Hilsch tube.

wikipedia: Ranque-Hilsch vortex tube

 

In May, 1947 William Taylor of the National Bureau of Standards published Vortex tube experimental results that described another hypothesis of how the tube works.  When compressed air passes through the entry nozzle, it speeds up and loses heat. The velocity gained results in a loss of heat energy.  This fast, cold air is then slowed as it spirals in the tube. The molecules of gas drop to the center of the tube.  Surprisingly, instead of heating up as they lose speed, they pass their energy to the next outer layer and remain cool. The additional cooling effect is caused by the centrifugal force of the whirlpool.  The centrifugal force “throws air molecules” out from the center so that there are fewer molecules and lower pressure. When the air molecules move from the high-pressure region of the tube to the lower pressure region in the center of the tube, the gas expands and cools.

1953. Westley published a comprehensive bibliography of the Vortex tube in 1954, containing brief development of the tube from 1931-1953.

In 1961, a General Electric engineer, named Charles Darby Fulton studied the Vortex tube carefully and developed it for commercial applications. Between 1952 and 1962 he obtained the following U.S. Patents related to the development of the Vortex tube:

• US2603535A: Liquid spray nozzle Filed July 15, 1952 INVENTER David C. Ipsen, Charles D. Fulton.
• US3208229A: VORTEX TUBE Filed Jan. 28, 1965 2 Sheets-Sheet 2 INVENTOR. CHARLES DA FULTON
• US3173273A: VORTEX TUBE Filed March 16, 1965

The goals of the US. Patent No. 3173273A were to:

• provide improvements in the Vortex tube so that they emit colder gas and a larger fraction of cold gas with increased efficiency for a greater range of applications
• Reduce leaks
• Increased ability to utilize high gas pressures efficiently
• Reduce the cost of manufacturing

His company, Fulton Cryogenics, manufactured Vortex tubes and became the Vortec Corporation in 1968 to expand and improve the Vortex product line for industrial and commercial applications. The Vortex tube was used to separate gas mixtures, oxygen and nitrogen, carbon dioxide and helium. In 1991, the Illinois Tool Works acquired Vortec Corporation to further study the Vortex tube for technological applications.

Research for nozzles lead to improvements in the Vortex tube design. Merkulov recommended the tip area being 9% of the  cross-section of the tube “with the axial width to be twice the radial depth.” He also inserted a cross in the tube and ultimately shortened the length of the Vortex tube and he received a US patent in 1968 (patent number US3522710A – F25B9/04).

The optimum length of the hot end suggested by Merkulov was 8 to 10 Dc (tube diameter).  In 1961, Dr. Parulekar published a paper based on a short Vortex tube:

1. A cylindrical or convergent piece of axial length equal to 6 mm.
2. A divergent truncated cone with axial length equal to 18mm.
3. Cover, which also forms the third part of the hot side is cylindrical and of axial Length equal to 20mm.

Research results determined that the roughness of the internal surface did not affect the results of the tube output – http://engineering-completed-project.blogspot.com/2015/02/project-on-vortex-tube-refrigeration.html

In 2001, Guillaume and Jolly performed a study on a two stage Vortex tube where the cold air from the first tube was injected into a second Vortex tube. They reported that the temperature difference at each stage was greater than would be generated from a single stage Vortex tube.

To optimize the performance of the Vortex tube, multi-stage Vortex tubes have been studied. Dincer in 2011 tried a “three-fold type and six cascade  type Vortex tube systems” consisting of three and six Vortex tubes connected in a series. Through this research, the greatest temperature drop occurred when six-cascade Vortex tubes were connected.

The curved Vortex tube, studied by Valipour and Niazi in 2011, proved that an increased in temperature difference was influenced by the curvature of the tube. The maximum refrigeration capacity occurred at 110-degree curvature. The maximum temperature difference was generated by a straight Vortex tube.

Other types of Vortex tubes that have been studied include Vortex tubes in various surroundings, insulated, non-insulted and the types of fluids used – such as water instead of compressed air, oxygen, methane and other gas mixture.

 

Experimentation Discoveries

Ranque discovered through extensive experiments that when the compressed air enters through the tangential nozzle and expanded cold air discharges through a small hole in the diaphragm. Simultaneously, hot expanded gas is discharged through the valve. The coldest gas is produced only when a small fraction of the gas is released through the small hole. It is recommended that the valve is opened widely for this to occur. The result is the hot gas cools to become warm gas.  The hottest gas is achieved by closing the valve. Then, nearly all the gas is released through the small hole and is cool.

The two major inefficiencies of this design are:

• Only a small fraction of the gas can be extracted at the lowest temperature
• The amount of temperature depression obtained never approaches that of an ideal expansion engine.

Continued research is required to determine the optimum configuration is complicated and challenging. There could be up to fifteen factors that need to be considered when optimizing the design. Here are a few:

• kind of gas
• gas pressure
• temperature
• rate of flow
• cold fraction to be delivered at a certain lower pressure

The research on Vortex tube also involves the compressible fluid dynamics of turbulent and unsteady flow, thermodynamics, and heat transfer. Westley stated, “Besides its possible importance as a practical device, the Vortex tube presented a new and intriguing phenomenon in fluid dynamics”.

Each of the above factors results in a change in condition for the remaining factors. Research to determine the optimized factors of using a Vortex tube continues because of the fluid and dependent nature of research results.

 

Applications of the Vortex tube

The Vortex tube invention impacted refrigeration, air conditioning, cryogenics, instrumentation, and controls. The Vortex tube excels in situations such as cooling a worker wearing a protective suite or electronic equipment in extraordinary hot environment. Research is often placed on cold gas because of its greatest importance and number of uses. Vortex tubes are useful where sometime heat and sometimes cooling  of persons or work environments are required. When using a Vortex tube, it is understood that when cold gas is generated, hot gas is also a bi-product.

Nex Flow strives for excellence and improvements in the Vortex tube technology and original design to best suite an application.  Nex Flow provides three standard sizes of the Frigid-X^® Vortex tubes:

• Mini size – uses 2, 4 or 8 SCFM
• Medium size — uses 10, 15, 25, 30 and 40 SCFM
• Large sizes — uses 50, 75, 100 and 150 SCFM.

Depending on the temperature and pressure the compressed air used, it is possible to achieve cold end temperatures as low as – 40 (-40 C) and even – 50 degrees F (-45.56 C).   Vortex tubes are used to cool electronics, machine operations, tools, CCTV cameras, soldered parts, gas samples, and heat seals. Contact Nex Flow expert technicians to help you decide the best Frigid-X® Vortex tubes for your application.

TRY NEX FLOW PRODUCTS BEFORE PURCHASING

Nex Flow offers in the USA and Canada (as do many of our representatives worldwide), a risk free product trial  to potential customers and it is done in such a way to benefit all sides. Usually the trial period is limited to a maximum 30 days but in some cases, especially for larger projects, that time can be extended. Pneumatics is not a technology that is easily understood by everyone.  Even in engineering schools, a great deal of teaching time is focused on hydraulics but very little in pneumatics.

If and when someone enters the pneumatic field – the focus is often in a very narrow area.   Air compressor companies may give lip service to an entire system but their focus is primarily on the compressor room.  A piping supplier would be focused on the piping and filtration companies would obviously be focused on the filters. Tooling, blow off, cooling and other end use application, the focus is too much on the use of the equipment without considering the entire system. That being said – it takes a great deal of experience, and deliberate interest in the entire system to truly give the best outcome to a customer.  For this reason, Nex Flow insists upon understanding the entire system and the issue faced by clients before making recommendation on what to try.

A good volume of customers are in the same position as someone freshly entering the pneumatics field, and except for some basics understanding from classes and workshops, a more in-depth explanation will often help with decision making. A partial understanding of the concept can sometimes lead to inappropriate installation and test. For example, if an air knife is installed and does not work, did the issue steam from the application or installation?


A real example occurred years ago at one facility where a 24” air knife was installed for a blow off application. The issue was that the unit was not powerful enough. What happened was that the person in charge had hooked up a very small diameter airline that was also quite long.  This caused excessive pressure drop in the airline so the actual pressure at the point of use was much lower and hence less powerful. At first – the installer refused that the airline might be too small – but once he accepted to change the airline diameter to a much larger one – everything was resolved.

Some companies supplying similar technology as Nex Flow® have their “application engineers” that is not always very knowledgeable about the whole system offer a 30 day unconditional trial period.  With this many returns happen because no one is really there to assist when there are issues. One of our current customer had such an experience with a competitor – so much that he was skeptical about whether the system can even work for the application. The competitor sent one unit for test – it didn’t work, so the unit was sent back. With Nex Flow – we help customers explore and learn about the actual system and pinpoint why it did not work. The issue was simple – the unit was simply hooked up without the appropriate parameters. Now – this customer is using our air knives and are quite happy.

So this is why Nex Flow personnel always probe deeper to not only understand the customer’s application but the customer’s environment, and system. Is there adequate compressed air?  What about cleanliness in the airline? We even ask if the compressor is far or near the application (and yes, that can make a difference in some cases). If an application is tried and does not work – we endeavor to understand why because we want to learn and improve too!  Nothing is sent for trial unless we are quite sure it will work. Of course sometimes we get the opportunity to explore a new applications where we sometimes cannot guarantee if the system will work but we will still try the test if the customer is willing.

The point of all this is simple – we recognize the value of both the customer’s time and ours.  It is to the benefit of both parties to understand the customer’s operation, and for the customer to understand both the potential and limits of Nex Flow® technology and the parameters of operation.

In some cases it may take time for us to review provided information and may need to inquire additional information. For customers who have already had experience using the technology. What’s very nice is that the client’s have tried and loved the product due to the high quality of manufacturer and the “extra” we provide in each product. For example, most air knife providers do not anodize their aluminum versions – we do.  Our cabinet enclosure coolers are all stainless and even less costly than aluminum versions provided by old competitors. We enjoy product comparisons and as our team of researchers and engineers constantly strive to improve our products.

If you are not familiar with Nex Flow technology, or maybe you have used competitive products, successfully or non-successfully but not familiar with the Nex Flow® brand-  we certainly encourage to try before you buy!

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.

 

LOUDER DOES NOT MEAN MORE POWER

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^®.

Everything about Bypass System for Control Panels

The Nex Flow Panel Cooler is a vortex tube operated air conditioning system used to cool electrical and electronic control cabinets. They have many advantages such as simplicity in installation, near zero maintenance, no condensate and more. But one major advantage for control cabinets in harsh environments is that when operating they keep control cabinets at a slightly positive pressure, therefore keeping out the factory atmosphere. Panel Coolers are utilized especially in environments that are very dirty, dusty, hot and moist, or corrosive. This ability to keep the control panels at a slightly positive pressure becomes very important. However, this is only the case while the Panel Cooler is actually operating.

On-off control

One of the ways to minimize compressed air use with a Panel Cooler or any vortex cooling system is to have some sort of an on-off control system. One method is to use a thermostat coupled with a solenoid valve to turn the compressed air on when the cooling is needed, or turn the air off when it is not required. However, when the Panel Cooler is off, it no longer keeps the control panel at that slight positive pressure. It is at this point where the factory environment can encroach into the control cabinet and possible to have a negative impact on the internal components.

 

Single VS Multiple Panel Coolers

If there are two or more Panel Coolers on a control cabinet, normally one runs continually and the other one (or ones(s)) cycle on and off as required for cooling. That is enough to keep the control panel, even if very large, at the slightly positive pressure enough to keep out an unfriendly environment. But when only one Panel Cooler is used then some creativity is needed.

One of the tricks of the trade in factories such as highly humid bottling facilities, even with standard air conditioners, is to take a small compressed air line and pipe a very small amount of compressed air constantly into the cabinet to keep out the humidity that could harm the controls. A typical Standard air conditioners go on and off, so the humidity needs to be addressed. Similarly in very corrosive and dirty environments, a tiny amount of compressed air piped into the panel solves the potential expensive repair of the internal parts of an electrical or electronic enclosure.

So what are the options when using a single Panel Cooler? One vortex cooler supplier uses a thermostat and solenoid package for on-off control but they drill a small hole into the solenoid valve so that in the “off” position, a small amount of compressed air continues to flow through the cooling unit.  There is not enough flow to effectively cool in the off position but enough flow to keep the cabinet at a higher pressure than the environment.

There are two disadvantages with this method.  

First, it may not be legal in some jurisdictions because drilling a hole in the solenoid valve may take away its electrical approval rating. This may result in all sorts of problems from insurance coverage to legal should something go wrong.  

Second, there is no control over how much of this air can go into the cabinet. For very large cabinets, it may not be enough air to make any difference in pressure, and for small cabinets there may be too much air flow that it wastes energy.

 

Overcoming the disadvantages

To overcome the above disadvantages – Nex Flow has designed a special by-pass system.

The by-pass system works with all panel coolers both Nex Flow and non-Nex Flow units. It consists of a control valve that is connected between the compressed air supply (after filtration) at the inlet to the solenoid valve that controls the on-off operation of the vortex cooling system.  There is a small tube emanating from the control valve that is connected to a three-way fitting that connects to the outlet of the solenoid valve. One inlet is for the tube, a second inlet connects to the outlet of the solenoid, and the other connection goes to the line that takes the compressed air to the cooling unit.

This overcomes both the previous disadvantages mentioned. The solenoid valve is not tampered with so no electrical approvals are jeopardized and eliminating any potential insurance or legal issues.

The control valve on the inlet side of the solenoid valve has a small knob to set the amount of by-pass compressed air used. It can be set to a very small flow rate for small control panels to save energy and a higher flow rate for larger control panels to insure there is enough air flow to maintain a higher pressure than the environment. Control remains completely in the hands of factory personnel and not with a tampered solenoid valve.

The Panel Cooler by-pass system is also made of all 316 stainless steel so it can be used in all types of environments and with all ranges of Panel Coolers offered by Nex Flow (and their competitors) including NEMA 4X (IP 66) environments. The system is simple to install, easy to use and versatile.

In relatively benign factory environments, a by-pass system may not be necessary. Furthermore, if the Panel Coolers operate continuously they are obviously not required. To determine if having a by-pass system would be beneficial, you simply have to access the plant environment. In corrosive atmospheres or highly humid atmospheres the benefit is quite clear cut. However, regardless of the environment, when used, they have been proven as an effective way to keep the internals of a control clean and dry.

If there is more than one Panel Cooler, as mentioned earlier, normally one is always operating.  However, if the plant atmosphere is really harsh, it might still be useful to have a By-Pass System on at least one cooling unit assuming the control panel is completely shut down during a plant shutdown.

As with all Panel Cooler installations, it is important to have proper filtration to remove any loose water or oil to keep the system clean and dry.  

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The biggest criticism against vortex tube-operated air conditioners for control panels is their use of compressed air. Still, in certain situations, it just makes sense to use them depending on the importance of reliability and the nature of the factory environment.

Nex Flow Air Products Corp. manufactures compressed air-operated products for blow-off, moving, and cooling applications to optimize the use of energy with safety and the environment in mind.

Video url : https://youtu.be/dBjuJaIjw9w

Vortex Tube operated cabinet enclosure coolers such as the Nex Flow Frigix-X Panel Coolers operate utilizing compressed air wherein one end gets hot, and the other end gets cold. They find applications in particularly dirty environments and hot and wet factory climates.

Because of the rough environments they are subjected to, construction materials are pretty necessary. Some manufacturers utilize stainless steel with the vortex tube (cold temperature generating portion) and then packaged it in an aluminum housing and assembly, usually not anodized. So after a short time, the appearance of the aluminum, especially if not anodized in such environments, look pretty deteriorated.

But it is mainly in hot and humid environments where the combination of stainless steel with aluminum can be a problem due to the possible effect of galvanic corrosion between these two very dissimilar metals. Due to this corrosion effect, I have personally seen a vortex-style cabinet enclosure cooler with a big gaping hole in its aluminum housing.

So if choosing vortex tube operated cabinet enclosure coolers, it is a good idea to check what they are made off. Nex Flow makes them from stainless steel. The vortex tube, housing, and attachments are stainless to avoid this corrosion issue. Stainless steel will obviously hold up much better than aluminum in a nasty factory environment.

Nex Flow manufacturers specialized compressed air products for blowoff, cooling, and moving c/w quality accessories for controlling, monitoring, and filtering compressed air.

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When choosing the means to cool control panels or any electrical and electronic enclosure, you need to consider the control panel rating and factory environment before selecting the best method.

Nex Flow Air Products Corp. manufacturers and markets specialized compressed air technology for cleaning, drying, blow off, moving and cooling including vortex tubes and products that incorporate vortex tube technology.

Video url : https://youtu.be/9_NTZsl6VAE

NEMA and IP Classifications Equivalency

l and electronic enclosures while Europe and many other countries utilize IP classifications. This often causes some confusion. We found a great chart from Siemon that do IT infrastructure solutions what has a very concise equivalency chart.

This reference chart will be useful when choosing

https://www.nexflow.com/cabinet-enclosure-coolers/

for air conditioning control panels anywhere in the world.

Nex Flow Air Products Corp. manufacturers specialized compressed air products for cleaning, drying, blow off, moving and cooling applications. They lead in vortex cooling technology development. A major application for vortex cooing is for electrical and electronic enclosures, especially is very humid, hot and dirty environments where regular air conditioners would entail much higher maintenance costs and shorter life.

NEMA and IP Classifications Equivalency

Galvanic corrosion and materials

Galvanic corrosion occurs when two dissimilar metals come into contact. It is also necessary for there to be moisture, but it is rare to find an environment without moisture. I still remember visiting a factory and seeing a competitor’s Cabinet Enclosure Cooler (using vortex tube technology) with a big hole on the aluminum cover, obviously caused by some form of corrosion. While the unit was still functioning, this gaping hole made dirt buildup inside the system a definite probability of shortening the life of the unit which, if it used proper materials, or at least anodized the aluminum could last 20 years.

Air blow off products such as air knives, and amplifiers use (usually) aluminum or zinc. Air knives in particular are normally made of aluminum with steel, or stainless steel screws. The further apart the different metals that are matched together are, in terms of relative potentials, the greater the possibility of galvanic corrosion in a wet or humid environment. For example, stainless steel in contact with copper is less likely to be a risk than when it is in contact with aluminum or galvanized (zinc coated) steel. Seawater or salt laden moist air is more of a risk than contact with rain water or say water used for wash down in a factory. Vortex tube operated cabinet enclosure coolers are typically assembled using stainless steel vortex tubes since stainless is the most common material used for vortex tubes due to long life and durability. The surprise is that some manufacturers still, after many years, use aluminum for mufflers, sleeves and casings exposed to a potentially wet factory environment with a stainless steel vortex tube. As long as the environment stays dry, it is not a problem but if the environment is wet, or the enclosure cooler is used in a wash down environment such as in a NEMA 4 (IP56) area, then the risk of galvanic corrosion is much higher.

Anodizing the aluminum is one way to help prevent that from happening as it provides insulation to the galvanic action. But some manufactures of these units have not even done that.

Nex Flow Air Products Corp. uses stainless steel vortex tubes and stainless steel muffling, sleeves, etc. – no aluminum in their cabinet enclosure coolers (Panel Coolers) to avoid galvanic corrosion which can occur if the units are subjected to a humid environment or wash down procedures. Their NEMA 4 (IP 56) units are stainless steel for NEMA 4-4X environments.

What also comes into play is the surface area of each material used. For example, if there is a large area of aluminum and a little stainless steel screw, there will not be much of a problem. Aluminum air knives for example can have stainless steel screws and the galvanic action remains minimal. Nex Flow anodizes their aluminum material to be extra cautious. Most compressed air operated air knife producers however do not anodize. (The near term negative effect of a factory environment on non-anodized aluminum is another topic.)

To keep the aluminum/stainless mix acceptable, the stainless part should be small and the aluminum part large, and of course, keep them dry and away from a humid area. Better still, either anodize the aluminum or just do not mix the materials.

Nex Flow Air Products Corp. manufactures compressed air operated products for blow off, drying, cleaning, cooling and moving along with specialized pneumatic technology to reduce noise, energy use, and to improve the compressed air productivity in a factory environment.