The EXAIR Mini Cooler family is one of the many vortex tube based Spot Cooler products that EXAIR offers. This is the smallest of the group coming in at 550 BTU/hr of cooling capacity. The Mini Cooler Systems are available in two options.
The Single Point Outlet option will give you ten inches of flexible cold outlet to easily position the cold air stream near the target point.
The Dual Point Outlet option gives ten inches of 1/4″ flexible outlet that then splits to two separate four inch lengths of 1/4″ flexible cold outlet hoses.
Both include point or flat fan tips for the cold air outlets
Both include a manual drain filter separator
both include the swivel magnetic base with 100 lb. pull magnet.
The single point hose kit is ideal for small diameter milling or drilling applications where the cold air can cover the contact area of the cutter. It can also be used on soldering, industrial sewing, ultrasonic welding, or even small punching applications to list just a few.
The dual point hose kit is ideal for two separate small diameter cutters, one larger diameter cutter, rotary style knives where there material is being slit, or larger diameter multi-point ultrasonic welders/punches.
When using the Mini Cooler the adjustable cold outlet stays in place and can easily bend around fixtures, spindles, welding horns, or dye aligning pins. The swivel magnetic base gives additional adjustment at the base of the cooler to aid in the versatility of this product. To further the adjustability of the cooler the operating pressure can easily be adjusted to lower or raise the cooling capacity of the Mini Cooler to meet the demands of the precise application.
If you believe you have an application that would benefit from the use of a Mini Cooler, or you are unsure which product would be ideal for your application please contact an Application Engineer. we are all here, willing to help however possible to get your application improved in both safety and efficiency.
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.
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
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
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.
Heat within an electrical cabinet can be a major issue for manufacturing companies. The costs associated with down time and repairs on sensitive electronics that fail due to heat or environmental contaminants, are an unnecessary burden. If you have any questions about how an EXAIR Cabinet Cooler can solve problems in your facility, contact an EXAIR Application Engineer.
The Vortex Tube is a low cost, reliable, maintenance free way to provide cooling to a wide variety of industrial spot cooling problems.
There are two (2) popular uses for the Vortex Tubes. One is to spot cool a warm item as fast as possible. The other is to chill an item to as low a temperature as possible. Because these are very different requirements, different Vortex Tube configurations exist to handle each.
For those applications of spot cooling, we recommend the 3200 series of Vortex Tubes. They are designed to be most efficient at providing maximum refrigeration, which is a function of high cold air flow rate and moderate temperature differential of the cold air to the warm item.
And for those applications of chilling an item to a very low temperature at low flow rate , we recommend the 3400 series of Vortex Tubes. They are designed to be most efficient at providing maximum cold air temperatures, but with a lower cold air flow rate.
An important parameter for the Vortex Tubes is the Cold Fraction. By adjusting the hot valve on a vortex tube, the amount of air that is discharged through the cold end changes. When expressed as a percentage of the total compressed air that is supplied to the vortex tube, we get the Cold Fraction. For example, if the hot valve is adjusted so that for every 10 parts of compressed air supplied, we get 7 parts of cold air, then we have a 70% Cold Fraction. When you know the Cold fraction setting and the compressed air supply pressure, you can use the Vortex Tube Performance tables and get the cold air discharge temperature.
Using the table below left, at 100 PSIG compressed air pressure and a 70% Cold Fraction, we can expect the cold air discharge temperature drop to be 71°F. With 70 ° compressed air temperature, the cold air will be at -1°F.
The 3200 series of Vortex Tubes are for use in the 50-80% Cold Fraction range, and the model 3400 series is designed for use in the 20-50% Cold Fraction ranges, to maximize the performance of each.
In summary, the selection of the Vortex Tube that best meets the application needs is based on the desired cold air flow rate, and the temperature of air desired. Once these are known, using the tables can provide the information needed to select the best option.
For those applications where we are unsure what will work best, we offer the EXAIR Cooling Kits, that include a Vortex Tube (small, medium, or large) and an array of Generators, to allow the configuration of the full range of Vortex Tubes within each size family.
Model 3908 – Small Vortex Tube Cooling Kit – build models 3202, 3204, 3208, and 3402, 3404, 3408
Model 3930 – Medium Vortex Tube Cooling Kit – build models 3210, 3215, 3225, 3230, 3240, and 3410, 3415, 3425, 3430, 3440
Model 3998 – Large Vortex Tube Cooling Kit – build models 3250, 3275, 3298, 3299, and models 3450, 3475, 3498, 3499
If you have questions about Vortex Tubes or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.
The EXAIR Vortex Tubes use compressed air to generate a cold air stream at one end and a hot air stream at the other end. The history behind this phenomenon is rooted in the Ranque-Hilsch tube. In 1931, a French physicist, Georges Ranque, tried to use a cyclone vortex to separate iron filings from the air. He noticed that when he capped one end with a slight opening, the air would become very warm. Being disappointed with the separation, he shelved his patented idea for several years. In 1946, Rudolf Hilsch picked up this idea from Georges Ranque and “tweaked” the design. This product has now become known as the Vortex Tube. In this blog, I will cover Rudolf Hilsch as a person of interest.
Rudolf Hilsch was born in December 18th, 1903 in Hamburg, Germany and died on May26th, 1972. In 1927, Rudolf received his doctorate at the age of 24. In 1938, he worked with a colleague, Robert Pohl, to create one of the first working semiconductor amplifier. From 1941 to 1953, Hilsch was a professor of physics at Erlangen, and in 1947, he published his paper of the Ranque-Hilsch tube which he called the “Wirbelrohr”, or whirl pipe. This publication became well known and was the start of the Vortex Tube. To continue on with his career, in 1953, he became a full member of the Bavarian Academy of Sciences. Also, at that same time, he started teaching physics at the Physics Institute of the Georg August University of Göttingen well into the 1960s.
To expand a bit more into his publication, the design for spinning the air at a high rate of speed can produce a separation of temperatures. It starts with a generator to help facilitate a vortex. As the vortex travels toward one end, a portion of that air will travel back through the center toward the opposite end. (Reference animation above). As these two vortices interact, conservation of momentum forces the inner vortex to give off energy in a form of heat to the outer vortex. This separation of temperatures will give you a hot air stream and a cold air stream. This type of device can do this without any moving parts or Freon. You just have to supply a compressed gas.
EXAIR manufactures Vortex Tubes that utilize this phenomenon with compressed air. We stock units with cooling capacities up to 10,200 BTU/hr and can reach temperatures from -50oF to +260oF (-46oC to +127oC). So, thank you Mr. Ranque and Mr. Hilsch for creating a product to generate hot and cold air in a single unit. If you would like to discuss any applications where cooling or heating is needed, you can talk with one of our Application Engineers. We will be happy to help.
The Adjustable Spot Cooler is a low cost, reliable , maintenance free way to provide spot cooling to a myriad of industrial applications. Simply turn the knob, and the temperature can be changed to suit the needs of the process. The Adjustable Spot Cooler delivers precise temperature settings from -30°F (-34°C) to room temperature.
It can produce temperatures form -30°F to +70°F (-34°C tp +21°C)
Parts included for flow rates of 15, 25 and 30 SCFM (425, 708, 850 SLPM.) The unit comes from the factory set at 25 SCFM (708 SLPM)
It can produce refrigeration up to 2,000 BTU/hr (504 Kcal/hr.)
A swivel magnetic base allows for easy mounting and portability, you can move it from machine to machine as needed. The flexible cold air outlet tubing holds its position and is easy to aim. Most importantly, there are no moving parts or CFC’s, ensuring maintenance free operation.
The Adjustable Spot Cooler incorporates a vortex tube to convert a supply of compressed air (1) into two low pressure streams, one hot and one cold. With the turn of a knob, the temperature control valve (2) allows some hot air to flow through a muffling sleeve and out the hot air exhaust (3). The opposite end provides a cold air stream (4) that is muffled and discharged through the flexible hose, which directs it to the point of use. The swivel magnetic base (5) provides easy mounting and portability.
The Adjustable Spot Cooler can produce a wide range of air flows and temperatures as determined by the temperature control valve knob setting and the generator installed. The generator controls the total SCFM (SLPM) of compressed air consumption, and is easy to change. From the factory, the 25 SCFM (708 SLPM) generator is installed, producing up to 1,700 BTU/hr (429 Kcal/hr) of cooling. For less cooling, the 15 SCFM (425 SLPM) generator can be installed, providing up to 1,000 BTU/hr (252 Kcal/hr) of cooling. And for more cooling, the 30 SCFM (850 SLPM) generator can be installed, providing up to 2,000 BTU/hr (504 Kcal/hr) of cooling.
Two (2) Systems are available as shown below, and include the 15 and 30 SCFM (425 and 850 SLPM) generators, a filter separator, and either a single or dual point hose kit.
Adjustable Spot Cooler Systems
If you have questions about the Adjustable Spot Cooler or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.
Heat is an unavoidable by-product of any cutting or machining operation. Think about it: you’re creating friction on a piece of material with a fast-moving piece of harder material in order to forcibly separate pieces of the original material from its existing shape & size. No matter what, something’s going to get hot: the work piece, the tooling, or (almost always) both. If you don’t do something about it, your parts can become damaged, your tooling can become dull and brittle, and productivity will suffer.
There are ways to alleviate the problem…you can slow the speed of your tooling, but that’s hardly practical, and only marginally effective. You can use liquid cooling…in fact, you may have to if the particulars of the operation require the lubrication you can only get from a cutting oil or liquid coolant. But those can be messy, expensive, and the time you spend maintaining the coolant could certainly be spent better elsewhere…like, on machining your products!
The Cold Gun uses compressed air to produce a stream of clean, cold air at 50°F (28°C) below supply air temperature.
They use Vortex Tube technology…no moving parts to wear out.
Cold flow and temperature are preset to optimize cooling capability, and are non-adjustable to prevent freeze-up during use.
Eliminates the expense of both the purchase & disposal of cutting fluids.
Removes the potential for health problems associated with breathing mist & vapors, and the safety issue of slipping on a wet floor.
Cold Gun Aircoolant System selection is easy & straightforward…we offer a standard, and a High Power version to meet your specific needs.
We also offer Single & Dual Point Hose Kits, to further meet the needs of your application. Right now, you don’t have to decide up front…order a Cold Gun Aircoolant System with a Single Point Hose Kit before December 31, 2018, and we’ll throw in the Dual Point Hose Kit for free.
If you’d like to find out more about how Cold Gun Aircoolant Systems can improve your machining or cutting operations, give me a call.
Visit us on the Web
Follow me on Twitter
Like us on Facebook
There are many theories regarding the dynamics of a vortex tube and how it works. Many a graduate student has studied them as part of their research requirements.
The Vortex Tube was invented by accident in 1928, by George Ranque, a French physics student. He was performing experiments on on a vortex-type pump that he had developed and noticed that warm air exhausted from one end and cold air from the other! Ranque quickly stopped work on the pump, and started a company to take advantage of the commercial possibilities for this odd little device that produced both hot and cold air, using only compressed air, with no moving parts. The company was not successful, and the vortex tube was forgotten until 1945 when Rudolph Hilsch, a German physicist, published a widely read paper on the device.
A vortex tube uses compressed air as a power source, has no moving parts, and produces hot air from one end and cold air from the other. The volume and temperature of the two air streams is adjustable with a valve built into the hot air exhaust. Temperatures as low as -50°F (-46°C) and as high as 260°F (127°C) are possible.
Here is one widely accepted explanation of the physics and the phenomenon of the vortex tube.
Compressed air is supplied to vortex tube and passes through nozzles that are tangent to to an internal counterbore (1). As the air passes through it is set into a spiraling vortex motion (2) at up to 1,000,000 rpm. The spinning stream of air flows down the hot tube in the form of a spinning shell, like a tornado (in red). The control valve (4) at the end allows some of the warmed air to escape (6) and what does not escape reverses direction and heads back down the tube as a second vortex (in blue) inside of the low pressure area of the larger warm air vortex. The inner vortex loses heat and exits the through the other end of as cold air (5).
It is thought that that both the hot and cold air streams rotate in the same direction at the same angular velocity, even though they are travelling in opposite directions. A particle of air in the inner stream completes one rotation in the same amount of time that an air particle in the outer stream. The principle of conservation of angular momentum would say that the rotational speed of the inner inner vortex should increase because the angular momentum of a rotating particle (L) is equal to the radius of rotation (r) times its mass (m) times its velocity (v). L = r•m•v. When an air particle moves from the outer stream to the inner stream, both its radius (r) and velocity (v) decrease, resulting in a lower angular momentum. To maintain an energy balance for the system, the energy that is lost from the inner stream is taken in by the outer stream as heat. Therefore, the outer vortex becomes warm and the inner vortex is cooled.
If you have questions about Vortex Tubes, or would like to talk about any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.