EXAIR Cabinet Cooler vs. Air-To-Air Heat Exchanger

The EXAIR Cabinet Cooler family.

At EXAIR we’ve been providing enclosure cooling solutions for decades, and in many cases those cooling solutions have remained in place for decades as well.  In the time we’ve been in the market with industrial enclosure cooling solutions we’ve encountered a number of alternative means for enclosure cooling.  One of those methods is an air-to-air heat exchanger.

An air-to-air heat exchanger uses the temperature differential between the ambient air surrounding an enclosure and the hot air inside an enclosure to create a cooling effect.  A closed loop system exchanges the heat inside the enclosure with the outside air in an effort to maintain a set internal temperature.  The heat exchange of most air-to-air unit relies on a heat pipe, a heat-transfer device which converts an internal refrigerant liquid into vapor by placing one end of the pipe in contact with the hot environment.  The heated vapor travels to the other end of the pipe which is in contact with a cooler environment.  The vapor condenses back into a liquid (releasing latent heat) and returning to the hot end of the pipe and the cycle repeats.  All in all, a clever solution.

But, this type of a solution does give some cause for concern, especially when considering their use in an industrial environment.  Here are the key points to keep in mind when comparing an air-to-air cooler to an EXAIR Cabinet Cooler.

Required temperature differential based on ambient air temp

An air-to-air heat exchange relies on the ΔT between the ambient air temperature and the internal enclosure air temperature to produce cooling.  If this ΔT is low, or the ambient temperature rises, cooling is diminished.  This means that as the temperatures in your facility begin to rise, air-to-air heat exchangers become less and less effective.  Larger air-to-air heat exchangers can be used, but these may be even larger than the enclosure itself.

EXAIR Cabinet Coolers rely on the ΔT between the cold air temperature from the Cabinet Cooler (normally ~20°F) and the desired internal enclosure temperature (normally 95°F).  The cold air temperature from the Cabinet Cooler is unaffected by increases in ambient temperatures.  The large ΔT and high volume cold air flow produced by a Cabinet Cooler results in more cooling capacity.  And, we can increase cooling capacity from a Cabinet Cooler without increasing its physical footprint, which is already much, much smaller than an air-to-air type of unit.

 

Cooling in high temperature environments

High Temperatures are no problem for EXAIR Cabinet Coolers

Due to their nature of operation, an air-to-air heat exchanger must have an ambient temperature which is lower than the desired internal temperature of the enclosure.  If the ambient air has a higher temperature, air-to-air units provide zero cooling.

Cabinet Coolers, on the other hand, can be used in hot, high temperature environments up to 200°F (93°C).

 

Cooling in dirty environments

An EXAIR NEMA 12 Cabinet Cooler in an extremely dirty environment. Still operating after over 7 years, without any maintenance.

Dirt in the ambient environment will impact cooling performance with an air-to-air heat exchanger.  In order for the air-to-air unit to effectively remove heat, the heat pipe must have access to ambient air.  With any exposure to the ambient environment comes the possibility for the ambient end of the heat pipe to become covered in ambient contaminants such as dust.  This dust will create an insulation barrier between the heat pipe and the ambient air, decreasing the ability for the heat pipe to condense the vapors within.  Because of this, most air-to-air devices use filters to separate the heat pipe from the ambient environment.  But, when these filters become clogged, access to ambient temperatures are reduced, and cooling capacity of the air-to-air unit reduces as well.

Cabinet Coolers have no problem operating in dirty environments.  In fact, it is one of their strengths.  Without any moving parts to wear out or any need to contact ambient air for cooling purposes, a dirty environment poses no problems.  In fact, check out this blog post (and this one) about EXAIR Cabinet Coolers operating maintenance free for years in dirty environments.

 

Size and time required to install

Air-to-air heat exchangers vary in size, but even the smallest units can have large dimensions.  Many applications have limited space on the enclosure, and a large, bulky solution can be prohibitive.  Couple this with the time and modification required to the enclosure to install a large air-to-air unit, and the “solution” may end up bringing additional problems.

Another key aspect of the Cabinet Cooler is its size.  Small, compact, and easy to mount on the top or side of an enclosure, Cabinet Coolers install in minutes to remove overheating problems.  Check out this video to see how simple Cabinet Coolers are to install.

Rising ambient temperatures translate to less natural heat transfer into the ambient environment.  As temperatures rise and overheating electrical components becomes a concern, remember EXAIR Cabinet Coolers as a viable solution.  If you have any questions about how an EXAIR Cabinet Cooler can solve problems in your facility, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Two Birds With One Stone (and A Shim)

Blowing off bottles is such a popular application for the EXAIR Super Air Knife, it’s been featured on the cover of our Catalog…several times…and is the “banner” pictures on the Super Air Knives page on our website:

This always makes me thirsty for orange soda.

I had the pleasure of helping a caller from a bottling plant recently with just such an application.  Thing is, they run a couple of different size bottles, and it’s not a very big facility…they didn’t want to, or have room to, install different lengths of Air Knives, and also didn’t want to waste air flow when they were running the shorter bottles.

9″ Air Knives were required for the taller bottles, but their shorter bottles were a little under 6″ tall.  They had considered buying both 6″ and 9″ Air Knives, but called me to see if there was a less expensive, and possibly, easier way.  (There is!)

EXAIR makes, and stocks, every product in our 208 page catalog right here in this building in Cincinnati, Ohio.  We also make custom parts when the need arises…and custom Air Knife shims were the solution to this customer’s application.

By installing two Model 110009 9″ Aluminum Super Air Knives, one on either side of the conveyor (just like the photo above,) they’re able to blow off the taller bottles.  When they run the shorter bottles, they change out the shims for ones that limit the flow to a 6″ curtain.

So…for a little under $50.00 (2017 cost for those custom shims,) they’re going to save almost $550.00 per year in compressed air costs – AND make sure that their compressed air system is optimized & available for other loads throughout the plant.

EXAIR offers the Super Air Knife in lengths from 3″ to 108″, with a 0.002″ shim installed.  They’re ideal for most industrial and commercial blow off applications, right out of the package.  If your application calls for something a little “outside the box,” you may only be a shim away from success.  If you have such an application, give me a call.

Russ Bowman
Application Engineer
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Vortex Tube Cools Glue On A Paper Folding Machine

I recently worked on a cooling application with an engineering company who designed a paper folding machine for their customer. As the paper enters the machine, it travels over a series of rollers or “plows” that folds the paper into the desired design. At the last step a heated glue is applied to the edge so the paper stays folded. After the paper leaves the folder it is sent to a stack machine to be processed and packaged for shipment. It was at this area they were starting to see some issues arise as the glue was retaining heat, causing it to leak onto the dividers of the stacker or other finished papers.

Example of a paper folding machine

To try and remedy the situation, the customer had installed an air nozzle to blow compressed air across the last fold and while this did work somewhat, they had to operate at really low pressure so they didn’t cause the paper to move while trying to cool the glue. This slowed the process down, which was negatively affecting their production output, so they reached out for assistance on a more reliable solution.

After further discussing the process with the design company, I recommended they use our Model # 3908 Small Vortex Tube Cooling Kit. The Vortex Tube Cooling Kits include the Vortex Tube, cold muffler, tubing, filter separator and all of the generators to change the flow rate and cooling capacity of the Vortex Tube during operation. The temperature drop from the supply air temperature and the volume of air being exhausted can be controlled by adjusting the valve in the hot end to change the cold fraction (the percentage of air being exhausted out of the cold end versus the amount of air being exhausted out of the hot end).

Items included in a Vortex Tube Cooling Kit

By incorporating the Cooling Kit into the process, the customer would be able to experiment with the airflow and temperature to achieve an acceptable balance, providing enough cold air to cure the glue, while not disrupting the process. If you have a similar process you would like to discuss, please contact an application engineer at 800-903-9247 for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

The Folding Machine 4 image courtesy of Ms. Tharpe via creative commons license

OSHA Standard 1910.242(b) – Dead-End Pressure and Chip Guarding Explained

OSHA Standard 1910.242(b) discusses the use of compressed air for cleaning and blowoff. It states that the use of compressed air for cleaning purposes is prohibited if the dead-ended pressure exceeds 30 psig. This phrase means the downstream pressure of the air nozzle or gun, used for cleaning purposes, will remain at a pressure level below 30 psig for all static conditions. In the event that dead ending occurs, the static pressure at the main orifice shall not exceed 30 psi. If it does exceed this pressure, there is a very high potential for it to create an air embolism. An air embolism, left untreated, can quickly impede the flow of blood throughout the body. This can lead to stroke, heart attack, and sometimes death. Take a look at the animation below to see how an air embolism can affect the body.

With this in mind, there are only two options for staying within compliance of this standard. Either install an engineered solution that will reduce the air pressure to less than 30 psig if dead-ended, or regulate the pressure below 30 psig. For the vast majority of operations, regulating the input pressure below 30 psig is useless. The force and flow from the nozzle at this pressure is greatly reduced and likely not enough to be effective in most applications. All of EXAIR’s Safety Air Guns are designed so that the flow cannot be dead-ended. The fins on the Super Air Nozzles are not only useful in amplifying the force by drawing in ambient air, but they also prevent an operator from completely obstructing the airflow.

sag-osha-compliant

The fins of the Super Air Nozzle allow air to escape and prevent dead-end pressure from exceeding 30 psig.

In addition to being concerned about dead-end pressure, OSHA 1910.242(b) also states that compressed air used for cleaning should include effective chip guarding. By this, they mean that some method or equipment must be installed that will prevent chips and particles from coming back into the eyes or skin of the operator. In addition to offering OSHA compliant nozzles and guns, EXAIR also has Chip Shields that can be installed onto any of our Safety Air Guns. The polycarbonate shields protect the operator from any flying debris while performing a drying or blowoff operation. Simply add a “-CS” to the end of any Safety Air Gun Model number to have a Chip Shield installed on the gun.

1210peek-cs

EXAIR’s Model 1210-PEEK-CS with Chip Shield

The Occupational Safety and Health Act of 1970 does not contain any provisions that allow for the approval or endorsement of equipment. Alteration or the misapplication of what was once a safe piece of equipment would create a dangerous scenario that is out of the control of the original manufacturer. Any nozzles or guns marketed as “OSHA approved” should immediately throw up a red flag. Identifying and implementing a safe, OSHA compliant solution rests in the hands of the manufacturer themselves. If you’ve got questions about compressed air safety or have an existing blowoff in place that does not adhere to this OSHA directive, give us a call. We’ll be sure to recommend a solution that will keep your operators and wallets safe!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@exair.com
Twitter: @EXAIR_TD

 

Air Amplifiers – Vent, Exhaust, Cool, Dry, Clean – With No Moving Parts!

As an Application Engineer, one of the interesting aspects of working with customers on applications is the varied types of solutions an EXAIR product can provide.  The Air Amplifier family – Super Air Amplifier, Adjustable Air Amplifier, and the special High Temperature Air Amplifier can be used in a wide variety of process and applications.  Below highlights several of those from past experiences.

A defense contractor was performing maintenance service on a Navy ship, and the ventilation system had to be shut down.  To keep the personnel cool and safe, an auxiliary ventilation was to be supplied.  Rather than use a cumbersome blower assembly, which has to mounted on the top deck, and ducted down to the lower decks, they chose to utilize (2) 4″ Super Air Amplifiers.  They are very portable and can be set up in minutes.  This solution provided the necessary air flow, providing a safe environment for the maintenance crew.

Super Air Amplifier

EXAIR Air Amplifiers use a small amount of compressed air to create a tremendous amount of air flow.

A light bulb manufacturer needed a better solution for a cooling operation.  During manufacturing of a mercury lamp, the bulb must be cooled from 700°C to 600°C in just 15 seconds.  The current method, an open brass pipe, was working but the noise level was too high (95 dBA.) The goal was to maintain the 15 second cooling time, but reduce sound levels to 85 dBA.  By utilizing (2) of 3/4″ Adjustable Air Amplifiers, the customer was able to maintain the cooling rate, and reduce the noise level down to 80 dBA, a 15 dBA reduction.

adjustable Air Amplifier

Adjustable Air Amplifier

A garbage collector presented a problem that needed a solution.  The garbage was incinerated and when the furnaces were first started up, there tended to be issues with getting the flue to draft properly.  Using the High Temperature Air Amplifier, the high velocity air flow and draw provided the needed draft until the stack warmed up and the natural draft would be established.  Since the unit is capable of handling temperatures up to 700°F, it was able to withstand the heat of the process after the compressed air was turned off.

These and other Applications for the Air Amplifiers and all other EXAIR products can be found on the EXAIR website on the Products page, under the Related Info section toward the bottom of each page.

If you have questions regarding Air Amplifiers or any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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EXAIR Manufactures Custom Vortex Tubes

EXAIR is based in Cincinnati, OH and it is where we design and manufacture our products. Since we are the manufacturer, we can design and build custom product when your application demands particular features. Vortex Tubes are the foundation of our cooling products and can be customized to suit your needs in many ways…

Vortex Family

The EXAIR Vortex Tube uses compressed air to generate a cold air stream at one end and a hot air stream at the other end.  This phenomenon in physics is also known as the Ranque-Hilsch tube.  It can generate very cold or very hot air without any moving parts, motors, or Freon.  Thus; making it low cost, reliable, and maintenance free.  The EXAIR Vortex Tube can generate

  • Air temperatures from -50 to +260 deg. F (-46 to +127 deg. C).
  • Flow rates from 1 to 150 SCFM (28 to 4,248 SLPM)
  • Refrigeration up to 10,200 BTU/hr (2,570 Kcal/hr)

Cooling or Heating with the Vortex Tube

With a wide range of cooling and heating applications, the EXAIR Vortex Tubes can be an ideal product for you.  They are used for cooling electronics, CCTV cameras, and soldered parts.  They are also useful for setting hot melts, gas sampling, and environmental chambers.  With its very compact and versatile design, it can be mounted in tight places to apply heated or cold air to your process.  The Vortex Tubes are used for improving process times in cooling, protecting equipment, or setting specific temperature requirements.  If you need a Vortex Tube to be more specific to your application, EXAIR can manufacture a proprietary product in the following ways:

Preset Vortex Tubes – the standard Vortex Tube has a screw on the hot end to adjust the cold and hot air temperatures.  To make the Vortex Tube tamper-resistant, EXAIR can replace the screw with a preset hot valve.  If you can supply the temperature and flow requirements for your application, EXAIR can determine the correct diameter hole to give you a consistent temperature and flow from the Vortex Tube.

Materials – The standard Vortex Tubes has a maximum temperature rating of 125 deg. F (52 deg. C).  For elevated ambient temperature, we offer a brass generator which will increase the temperature rating to 200 deg. F (93 deg. C).  If other materials are needed for food, pharmaceutical, or chemical exposure, we can also offer stainless steel for the hot plug, cold cap, and generator. I have seen Vortex Tubes made entirely from 316SS and even one made with a brass body. There are EXAIR Vortex Tubes with special material o-rings and hot valves or with customized muffler assemblies.

Fittings – Our standard units have threaded connections on the Vortex Tube to connect fittings and tubing.  In certain applications to improve mounting and assembly, special fittings may be required for ease of installation.  EXAIR can attach or modify these parts to the Vortex Tube to meet your requirements.

At EXAIR, we pride ourselves with excellent customer service and quality products.  To take this one step further, we offer specials to accommodate your applications.  As a manufacturer of the Vortex Tubes, we can work with our customers to generate a custom product with high quality, fast delivery, and a competitive price.  So, if you do need a special Vortex Tube to give you a specific temperature, ease of mounting, or a proprietary product for your OEM design, you can discuss your requirements with an Application Engineer.  We will be happy to help you.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

Pneumatically Conveying Corn Flakes From Large Sacks Using An EXAIR Line Vac

This workspace needs a pneumatic conveyance solution.

I’ve had a string of great Line Vac applications which I’ve been able to write about recently.  Using our Heavy Duty Line Vac to convey small particles, vacuuming alumina dust two applications in the same plant, and removing chips from a plastic CNC router.  But, the application for this blog is a bit different because it involved conveyance of a material to prevent worker fatigue.

Dried corn flakes in super sack.

The dried flakes shown above needed a reliable method to convey between the large sacks in which they’re delivered and the boilers into which they need to be added.  The existing operation has been to have personnel cut open the bags and pour them into the boilers, but this method is taxing for the workers and results in significant fatigue throughout the day as well as spillage around the boilers.  This facility needed a better way to move the corn flakes that was small enough to fit within the confined workspace and capable of quickly emptying the sacks over a distance of ~6.5 ft.

The corn flakes need to be conveyed from the sacks on the right to the boilers on the left.

This customer requested that the solution be made of 316 grade stainless steel, and that implementation and use be as simple as possible.  With a bulk density of ~40 pounds/cubic foot, and merely a desire to move the material as fast as possible over this short distance, I directed them toward our 3” Stainless Steel Line Vac made of 316SS.  To increase the conveyance in the application I also offered our service to convert our standard model 6066-316 Line Vac to a “High Power” unit by increasing the size of the generator holes.

Both of these solutions were deemed as viable because they both allow for fast emptying of the bags (we estimated between 1-2 minutes to completely empty a bag), little-to-no spillage, and far, far less fatigue on the workers in this area (the key driver for searching out a new method of material transfer.

The potential model numbers were presented to management for a purchasing decision.  As this project moves forward, and even after the solution is installed, we’ll be available for product assistance and engineering support.  If you have an application in need of a viable pneumatic conveyor, contact EXAIR.  We’ll be happy to explore the application and offer any potential solutions.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

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