Two weekends ago I had the pleasure of flying out to meet my friend in Colorado Springs and ski the weekend at Breckenridge. As an avid skier Breckenridge has been one of the resorts I have been wanting to ski since I started skiing out west. The weather was amazing and I couldn’t ask for better; the Saturday blue skies and cool breeze followed up by a Sunday of snow fall. The Trip was a dream come true. Breckenridge is specifically known for having high winds that howl across the peaks that stand at a max of 12,998 ft. above sea level. These chilling winds would freeze just about anyone if you aren’t dressed prepared for them as they blow right in your face on the lift. As I was sitting on the lift with these cold winds blowing in my face it brought to mind EXAIR’s Vortex Tubes, Cold Guns, and Cabinet Coolers.
EXAIR’s Vortex Tubes and similar products provide everything from a cool blast of air to a frigid breeze to cool off various parts and products. In a lot of smaller milling and grinding applications the Cold Gun has been used as a replacement to costly coolant-based alternatives. Vortex tubes have been used in cooling applications since 1945 and assist in everything from stress testing electronics to cooling down plastic parts during ultrasonic welding.
If you have any questions or want more information on how we use our vortex tubes to improve processes all over industry. Give us a call, we have a team of application engineers ready to answer your questions and recommend a solution for your applications.
Cody Biehle Application Engineer EXAIR Corporation Visit us on the Web Follow me on Twitter Like us on Facebook
Simply put, a Vortex Tube’s Cold Fraction is the percentage of its supply air that gets directed to the cold end. The rest of the supply air goes out the hot end. Here’s how it works:
No matter what the Cold Fraction is set to, the air coming out the cold end will be lower in temperature, and the air exiting the hot end will be higher in temperature, than the compressed air supply. The Cold Fraction is set by the position of the Control Valve. Opening the Control Valve (turning counterclockwise, see blue arrow on photo to right) lowers the Cold Fraction, resulting in lower flow – and a large temperature drop – in the cold air discharge. Closing the Control Valve (turning clockwise, see red arrow) increases the cold air flow, but results in a smaller temperature drop. This adjustability is key to the Vortex Tube’s versatility. Some applications call for higher flows; others call for very low temperatures…more on that in a minute, though.
The Cold Fraction can be set as low as 20% – meaning a small amount (20% to be exact) of the supply air is directed to the cold end, with a large temperature drop. Conversely, you can set it as high as 80% – meaning most of the supply air goes to the cold end, but the temperature drop isn’t as high. Our 3400 Series Vortex Tubes are for 20-50% Cold Fractions, and the 3200 Series are for 50-80% Cold Fractions. Both extremes, and all points in between, are used, depending on the nature of the applications. Here are some examples:
A candy maker needed to cool chocolate that had been poured into small molds to make bite-sized, fun-shaped, confections. Keeping the air flow low was critical…they wanted a nice, smooth surface, not rippled by a blast of air. A pair of Model 3408 Small Vortex Tubes set to a 40% Cold Fraction produce a 3.2 SCFM cold flow (feels a lot like when you blow on a spoonful of hot soup to cool it down) that’s 110°F colder than the compressed air supply…or about -30°F. It doesn’t disturb the surface, but cools & sets it in a hurry. They could turn the Cold Fraction down all the way to 20%, for a cold flow of only 1.6 SCFM (just a whisper, really,) but with a 123°F temperature drop.
Welding and brazing are examples of applications where higher flows are advantageous. The lower temperature drop doesn’t make all that much difference…turns out, when you’re blowing air onto metal that’s been recently melted, it doesn’t seem to matter much if the air is 20°F or -20°F, as long as there’s a LOT of it. Our Medium Vortex Tubes are especially popular for this. An ultrasonic weld that seals the end of a toothpaste tube, for example, is done with a Model 3215 set to an 80% Cold Fraction (12 SCFM of cold flow with a 54°F drop,) while brazing copper pipe fittings needs the higher flow of a Model 3230: the same 80% cold fraction makes 24 SCFM cold flow, with the same 54°F temperature drop.
Regardless of which model you choose, the temperature drop of the cold air flow is determined by only two factors: Cold Fraction setting, and compressed air supply pressure. If you were wondering where I got all the figures above, they’re all from the Specification & Performance charts published in our catalog:
A manufacturer of automotive power transmission shafts was experiencing frequent failure of high pressure plastic rollers on their spin tester. There are four rollers in a 90° array that center the shaft during spin testing. They exert a pressure of around 1,500psi onto the shaft while it’s rotating at 1,000rpm. This generates enough heat to actually melt the rubber coating on rollers, which means stopping testing (which holds up production) while they change out the rollers. Just for it to start all over again.
Thing was, they wanted to mount the Adjustable Spot Coolers where they could have access to the Temperature Control Valve, but the cold air Hose Kit wouldn’t reach the shaft. So they got a couple of extra sections of the cold air hose…they needed one section of the ‘main’ (shown circled in blue, below) to reach into the test rig’s shroud, and two sections of the ‘branch’ (circled in green) to reach to each roller.
Now, adding too much hose length will start to put line loss on the cold air flow, and it will pick up heat from the environment. But if you just need that extra foot of hose to get the job done, this generally works just fine. The extra foot or so they’ve added (5″ to the main and 6″ to each branch) has solved their problem…they haven’t had to replace a roller since the Adjustable Spot Cooler Systems were installed.
If you’re a regular reader of the EXAIR blog, you’re likely familiar with our:
This guideline is as comprehensive as you want it to be. It’s been applied, in small & large facilities, as the framework for a formal set of procedures, followed in order, with the goal of large scale reductions in the costs associated with the operation of compressed air systems…and it works like a charm. Others have “stepped” in and out, knowing already where some of their larger problems were – if you can actually hear or see evidence of leaks, your first step doesn’t necessarily have to be the installation of a Digital Flowmeter.
Here are some ways you may be able to “step” in and out to realize opportunities for savings on your use of compressed air:
Power: I’m not saying you need to run out & buy a new compressor, but if yours is
aging, requires more frequent maintenance, doesn’t have any particular energy efficiency ratings, etc…you might need to run out & buy a new compressor. Or at least consult with a reputable air compressor dealer about power consumption. You might not need to replace the whole compressor system if it can be retrofitted with more efficient controls.
Pressure: Not every use of your compressed air requires full header pressure. In fact, sometimes it’s downright detrimental for the pressure to be too high. Depending on the layout of your compressed air supply lines, your header pressure may be set a little higher than the load with the highest required pressure, and that’s OK. If it’s significantly higher, intermediate storage (like EXAIR’s Model 9500-60 Receiver Tank, shown on the right) may be worth looking into. Keep in mind, every 2psi increase in your header pressure means a 1% increase (approximately) in electric cost for your compressor operation. Higher than needed pressures also increase wear and tear on pneumatic tools, and increase the chances of leaks developing.
Consumption: Much like newer technologies in compressor design contribute to higher efficiency & lower electric power consumption, engineered compressed air products will use much less air than other methods. A 1/4″ copper tube is more than capable of blowing chips & debris away from a machine tool chuck, but it’s going to use as much as 33 SCFM. A Model 1100 Super Air Nozzle (shown on the right) can do the same job and use only 14 SCFM. This one was installed directly on to the end of the copper tube, quickly and easily, with a compression fitting.
Leaks: These are part of your consumption, whether you like it or not. And you shouldn’t like it, because they’re not doing anything for you, AND they’re costing you money. Fix all the leaks you can…and you can fix them all. Our Model 9061 Ultrasonic Leak Detector (right) can be critical to your efforts in finding these leaks, wherever they may be.
Pressure, part 2: Not every use of your compressed air requires full header pressure (seems I’ve heard that before?) Controlling the pressure required for individual applications, at the point of use, keeps your header pressure where it needs to be. All EXAIR Intelligent Compressed Air Product Kits come with a Pressure Regulator (like the one shown on the right) for this exact purpose.
First off, I want to dispel any notion that there might be something that’s NOT great about EXAIR Cabinet Cooler Systems. Are there other methods to provide effective cooling to an electrical panel? Of course there are, and frankly, if one particular method was clearly superior in any & every situation, the makers of that one would have put all the others out of business by now. But for now, let’s consider:
1. Simplicity: Cabinet Cooler Systems need compressed air to work. That’s it. Supply them with clean, moisture free air, and they’ll run darn near indefinitely, maintenance free. What could be easier?
2. Control: Continuous Operation systems have their place (more on that in a minute,) but in most cases, Thermostat Control is preferred, for a couple of reasons:
Most electrical and electronic components have a rated maximum operating temperature of 104°F (40°C). Maintaining the air temperature at a reasonable level less than that is all you need…any lower, and you’re just wasting energy, no matter what method of cooling you use. Our Thermostats are preset at 95°F (35°C) to ensure heat protection, while limiting operating costs.
There is such as thing as “too cold.” Particularly sensitive instrumentation & controls may exhibit varied behavior at different temperatures.
Our bimetallic probe-type thermostats are ideal for controlling air temperature. They have much faster response time than other mechanical styles, meaning the system won’t keep running once it’s cool enough, and it starts running as soon as it starts getting too hot. They’re also easy to reset, if the preset of 95°F (35°C) is not suitable for particular specific needs.
If constant monitoring, or frequent changes in control temperature are desired, the ETC Electronic Temperature Control offers these benefits, via a quick response thermocouple and pushbutton operation.
3. Environmental concerns: No matter where a panel is located in your plant, and what it might be exposed to, EXAIR Cabinet Cooler Systems will keep the environment out of that panel:
NEMA 4 systems provide the same protection as NEMA 12, and are additionally splash resistant, and are rated for indoor/outdoor duty.
NEMA 4x systems offer NEMA 4 protection, and are made of stainless steel for corrosion resistance.
HazLoc Cabinet Cooler Systems also maintain NEMA 4 or 4X integrity, and are for use with classified enclosure purge & pressurization systems in hazardous locations:
Class I Div 1, Groups A, B, C and D
Class II Div 1, Grouds E, F and G
4. Dependable protection: In most cases, the less moving parts something has, the more reliable it is. With NO moving parts, EXAIR Cabinet Cooler Systems absolutely prove this out:
Unlike refrigerant-based systems, there are no filters to clean, no coils to foul or corrode, and no electric motors to burn out.
No potential contaminants from outside air ever enter the enclosure…all the cold air comes from your compressed air supply, through an Automatic Drain Filter Separator fitted with a 5 micron particulate element and a centrifugal separator for moisture removal.
5. Selection: Cooling capacities range from 275 Btu/hr to 5,600 Btu/hr, and they’re all in stock, ready for immediate shipment.
6. Special considerations: “Customized” usually means high prices and long lead times. Not so for a number of EXAIR Cabinet Cooler System options:
High Temperature systems are available from stock, for installation in areas where the ambient temperature can exceed 125°F (52°C,) all the way up to 200°F (93°C.)
Continuous Operation Systems aren’t the only way to constantly keep environmental contaminants out…Non-Hazardous Purge (NHP) systems combine the efficiency of Thermostat Control by always passing a small amount of air flow, to provide a slight positive pressure, even when the temperature is lower than the Thermostat set point. This way, the Cabinet Cooler System only operates to maintain appropriate cooling, but the panel is still protected all the time.
When additional protection from harsh and corrosive environments is needed, or when specified by strict facility requirements (I’m looking at you, Food, Pharma, and Nuclear Plants,) our NEMA 4X Cabinet Cooler Systems can be provided in Type 316 Stainless Steel construction, from stock.
6.5 Simplicity, part 2: Not only are they simple to operate…
They install, in minutes, through a standard knockout in the top of your enclosure.
If there’s no room on top, or if it’s just more practical, you can put them on the side of the panel using a Side Mount Kit.
Don’t know which one to pick, or need help determining your heat load? Then use our Cabinet Cooler System Sizing Guide. There’s one in the catalog that you can fill out and fax or email to us, or you can find it on our website under the “Features” tab on any Cabinet Cooler product page…just fill in the blanks and click “Submit.” Or, you can always simply call in the data to an Application Engineer. We can calculate your heat load in just a minute or so, and we do it over the phone all the time.
If you’d like to find out more about heat protection for your electrical or electronic panels, give me a call.
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Although history only records back so far, I am certain (based on my experiences with sharp and heavy objects) that humans have been injuring themselves with tools, and the stuff they make with them, since the beginning of time. In fact, recorded history DOES bear this out…the famous Code of Hammurabi (circa 1750 B.C.) set specific amounts of compensation for specific injuries, as did laws from all over the ancient world, from the empires of Rome to China. Since then, we’ve come a long way in regulating safety not only for the worker in the workplace, but in public places, homes, and workplaces where manufactured products are used.
UL LLC (or Underwriters Laboratories, as they were known throughout the 20th Century) is a safety consulting & certification company founded in 1894 by an electrical engineer named William Henry Merrill. A year earlier, an insurance company hired Merrill to perform a risk assessment and investigation of new potential clients…George Westinghouse and Nikola Tesla, the proprietors of the Palace of Electricity at the 1893 Chicago World’s Fair. It was this experience that made him realize the potential for such an agency to test and set standards for product safety at the dawn of a new age of technology development. And 120 years on, the benefits in safety & protection have been proven many times over.
One of the more critical accreditations that a manufacturer can receive for a product is the UL Classified Mark. This differs from other markings (like the ones shown above for Certified, Listed, or Recognized) in that Classification means that samples of the product were tested & evaluated with respect to certain properties of the product.
EXAIR’s new Hazardous Location Cabinet Cooler Systems bear the UL Classified Mark. This means they meet the stringent UL requirements for installation on purged electrical enclosures in specific classified areas:
Class I Div 1, Groups A, B, C and D
Class II Div 1, Groups E, F and G
When choosing products for use in classified areas, it’s critical to ensure safety through compliance, and the HazLoc Cabinet Cooler Systems allow you to do that, with simplicity and reliability. If you’d like to discuss an enclosure cooling application, in or out of a classified area, give me a call.
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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.