Tag: Cooling

Adjustable Air Amplifiers: Versatile, Rugged, and EFFICIENT!

Published on by Jordan T ShouseLeave a comment

Adjustability is a key feature for several EXAIR Intelligent Compressed Air Products… for example our Adjustable Air Amplifiers.  The ‘adjustable’ part has to do with setting the air flow volume and force:

Just loosen the locking ring, and you can thread the plug out of, or in to, the body to increase, or decrease the flow and force of the developed flow.  There’s a hole in the plug (opposite the “EXAIR.com” stamp) so you can use a spanner wrench (another adjustable tool!) to thread the plug in or out.

You can get an amazing range of flow from a little twist*:

These are the performance values for a Model 6042 2″ Aluminum Adjustable Air Amplifier with a compressed air supply pressure of 80psig. Regulating the pressure can give you even lower…or higher…flows.                                              *0.002″ to 0.010″ is about 1/4 turn of the plug.

A gap of about 0.010″ is about the max for 80psig supply pressure.  Above that, the air flow overwhelms the Coanda profile, creating a turbulent ‘storm’ in the throat, hampering the efficiency and effectiveness. The proper “adjustment” for that is to select the next larger Air Amplifier!

While the range of air flow is certainly impressive, their versatility is another major factor in their selection.  I reviewed our Application Database (registration required) for real-life details on Adjustable Air Amplifiers “in the field” and found a litany of other benefits that made them better suited to particular installations than a Super Air Amplifier:

  • A customer who builds automated equipment incorporates the Model 6031 1-1/4″ SS Adjustable Air Amplifier to blow open bags with a puff of air as they move into position on an automated filling machine. They use it because it’s available in stainless steel construction, and it’s still compact & lightweight.
  • A mattress manufacturer uses Model 6043 3″ Aluminum Adjustable Air Amplifiers to cool mattress springs.  They’re lightweight, the perfect size to match the springs’ profile, and they can “dial them out” for high heat removal before putting springs on a rubber conveyor.
  • A tier 1 automotive supplier has Model 6234 4″ SS Adjustable Air Amplifier Kits installed on their robotic paint line to blow off moisture from parts to prevent water spotting between the wash cycle and the oven.  They use them because the stainless steel construction holds up to high heat due to the proximity to the ovens.
  • A food plant uses Model 6031 1-1/4″ SS Adjustable Air Amplifiers to improve the drying time of 3,000 liter mixers that must be washed between batches of different products.  The stainless steel construction holds up to the rigors of the frequent washdown in this area.
  • A bedding manufacturer replaced a regenerative blower with a Model 6041 1-1/4″ Aluminum Adjustable Air Amplifier for trim removal on stitched fabric at bedding manufacturer.  The blower was prone to failure from lint & dust; the Air Amplifier, with no moving parts, is not.  It’s also compact, lightweight, and virtually maintenance free.
  • A light bulb manufacturer installed Model 6030 3/4″ SS Adjustable Air Amplifiers on the ends of open pipes that were used to cool mercury lamp wicks.  This reduced noise levels significantly while providing the same cooling rate, and the stainless steel construction holds up to the heat of the operation.

Because of the simplicity of their design, Adjustable Air Amplifiers are also extremely adaptable to custom applications.  We’ve added threads or flanges to the inlets and outlets of several different sizes, to accommodate ease of mounting & installation:

Among other custom Air Amplifiers, we’ve put (left to right) threads on the outlet, ANSI flanges on the inlet/outlet, Sanitary flanges on the inlet/outlet, and Sanitary on the inlet/ANSI on the outlet. How are you installing your Air Amplifier?

Adjustable Air Amplifiers are available in both aluminum and 303SS construction, to meet most any environmental requirements…except extreme high heat.  In those cases, the Model 121021 High Temperature Air Amplifier is rated to 700°F (374°C) – significantly higher than the Aluminum – 275°F (135°C) or the Stainless Steel – 400°F (204°C).  They’re commonly used to circulate hot air inside furnaces, ovens, refractories, etc.

A Model 121021 1-1/4″ High Temp Air Amplifier directs hot air to a rotational mold cavity for uniform wall thickness of the plastic part.

Adjustability.  Versatility.  Durability.  If you’d like to know more about the Adjustable Air Amplifier, or any of EXAIR’s Intelligent Compressed Air Products, give me a call.

Jordan Shouse
Application Engineer

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Radiant Heat- Where Does It Come From

Published on by Brian FarnoLeave a comment
Even in extremely aggressive environments, EXAIR Cabinet Cooler Systems provide reliable heat protection for your sensitive electronics and controls.

The three types of heat transfer have been discussed here and there on this blog before. One of the most common heat transfer methods that I deal with on a day to day basis is radiant heat transfer. Also known as thermal radiation, the process is actually the exchange of energy by photons. The main difference separating radiant heat from convection and conduction is that radiation does not require there to be a medium to permit propagation of the heat. Any item which contains thermal energy, meaning it is above absolute zero and less than 1,000 Kelvin, will have this thermal energy. This thermal energy is radiated to other items causing a transfer of heat energy to those objects that results in an equilibrium between the items. The equilibrium does not stop the transfer of photons however.

The most common occurrence that most of us get to experience for radiant heat is heat from the Sun. As the sun shines it is emitting heat. On a hot day, generally the sun is a little closer to your geographic location and you feel hot because the sun is emitting more heat onto your surface than what is being emitted by your internal temperature, so your core temp will increase. On a cold day, when the sun is further away, while it is still shining you feel cold because the sun is not in fact transferring as much energy to the surface of your body than what you are internally generating. The same kind of radiant heat transfer can be from a campfire, open kiln, maybe even a hot steel slab coming out of a blast furnace.

The model 1126SSW 1″ Flat Stainless Steel Super Air Nozzle w/ Swivel Fitting cools a flame sensor within an industrial furnace.

Understanding where a radiant heat source is being generated can help tremendously when looking at cooling an electrical enclosure or even trying to keep a part or sensor cool. Radiant heat is one of the few times a heat shield or shade structure can help to eliminate a portion of the heat load being introduced. Other methods to combat the heat load would be determined with the application at hand. For cooling enclosures that are absorbing a solar heat load, we would look at an EXAIR Cabinet Cooler System and the factors that help to appropriately size the cooler. If this is a single component or part, we would evaluate one of the many other EXAIR Engineered Solutions to determine the best fit for the application. To do either of these, all it takes is a simple chat, email, or call to an Application Engineer.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Vortex Tube Cold Fraction and how it Affects Flow and Temperature Control

Published on by Jordan T ShouseLeave a comment

Vortex Tubes are the perfect solution when dealing with a variety of spot cooling applications. They use compressed air to produce a cold air stream and a hot air stream, with temperatures ranging from as low as -50°F  up to +260°F (based on ambient supply temperature) and providing as much as 10,200 Btu/hr. of cooling capacity. By simply adjusting the valve in the hot end of the Vortex Tube, you are able to control the “cold fraction” which is the percentage of air consumed by the vortex tube that is exhausted as cold air versus the amount of air exhausted as hot air. Our small, medium and large Vortex Tubes provide the same temperature drop and rise, it’s the volume of air that changes with the various sizes.

The unique physical phenomenon of the Vortex Tube principle generates cold air instantly, and for as long – or short – a time as needed.

When looking at the below performance chart, you will see that “Pressure Supply” and “Cold Fraction %” setting all play a part in changing the performance of the Vortex Tubes. Take for example, an operating pressure of 100 PSIG and cold fraction setting of 20%, you will see a 123°F drop on the cold side versus a 26°F temperature rise on the hot side. By the using the same Vortex Tube and keeping the operating pressure at 100 PSIG but changing the cold fraction to 80%, you will now see a 54°F temperature drop on the cold side and a 191° rise at the hot end.

Vortex Tube Performance Data
Vortex Tube Performance Chart

We’ve looked at how the cold fraction changes the temperature, but how does it change the flow for the various Models?

Say you are using a Model # 3240 Medium Vortex Tube which consumes 40 SCFM @ 100 PSIG. Again with the cold fraction set at 80% (80% of the consumed compressed air out of the cold end), you would flow 32 SCFM at the cold air exhaust.

40 SCFM x 0.8 (80% CF) = 32 SCFM

Using the same Model # 3240 Medium Vortex Tube but now with a 20% cold fraction (20% of consumed compressed air out of the cold end), you would flow 8 SCFM at the cold exhaust.

40 SCFM x 0.20 (20% CF) = 8 SCFM

As you can see, to achieve the colder air temperatures, the volume of cold air being exhausted is reduced as well. This is important to consider when making a Model selection. Some other considerations include the operating pressure which also has a significant effect on performance. The compressed air supply temperature is important because the above temperatures are temperature differentials, so in the example of the 80% cold fraction there is a 115F temperature drop from your inlet compressed air temperature.

If you need additional assistance, you can always contact myself or another application engineer and we would be happy to make the best selection to fit your specific need.

Jordan Shouse
Application Engineer

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Have A Blast (Of Cold Air) With EXAIR Vortex Tubes & Spot Cooling Products

Published on by Russ BowmanLeave a comment

The operation of a Vortex Tube is one of the more peculiar phenomena in fluidics, and a particularly unique method of producing cold air. Since they don’t perform “heat transfer” in the classical sense (see below), there’s no RATE of heat transfer…they’re generating cold air, at rated flow and temperature, instantly.

Compressed air enters the Vortex Tube (blue arrow) where the Generator imparts a spinning motion to the flow, which continues towards the “hot end” (red ribbon). The flow is forced to change directions and continue spinning, flowing in the opposite direction (blue ribbon). It’s at this point that the flow gives up energy in the form of heat, which is exhausted through the Hot Valve (red arrows) while the cold flow makes its way to the opposite end, where it exits at temperatures up to 129F colder than the compressed air supply.

EXAIR Corporation’s Vortex Tubes come in a range of sizes & cooling capacities, and are integrated into a number of Spot Cooler Products which add convenience and flexibility to their operation. Consider:

  • Vortex Tubes themselves are perfect for the most basic of installations. Small and Medium models weigh only a few ounces; you can thread them directly onto an existing 1/8 NPT (Small) or 1/4 NPT (Medium) fitting, if you have one (or can get one) adjacent to where you want to blow the cold air. Hot and Cold Mufflers can be added for sound attenuation, and the Cold Caps have 1/4 NPT (Small) or 3/8 NPT (Medium) female threads if you want to use a short pipe or hose to direct the cold flow.
  • Most spot cooling applications are best handled with the higher air flows and moderate temperature drops associated with a Vortex Tube product set to a high cold fraction. We have three distinct products that have a pre-set, non-adjustable cold fraction, aimed at these situations:
    • Mini Cooler Systems are quiet, compact, and ready to install in minutes via a Swivel Magnetic Base. They’re ideal for cooling small tools, needles in industrial sewing machines, saw blades, or lens grinders, just to name a few of the more popular applications. These come with built-in hot muffler, and are available with a Single or Dual Outlet Cold Air Hose Kit.
    • For applications that call for a higher cooling capacity, we offer the Cold Gun Aircoolant Systems. These have a bar magnet built in to the Cold Gun itself, integral Hot and Cold Mufflers, and, like the Mini Coolers, come with Single or Dual Outlet Cold Air Hose Kits. They’re most popularly specified to replace mist coolant in machine tools, but are also used on routers, grinders, drills, larger saws, and even some non-machining applications like chill rolls and setting hot melt adhesives.
    • For even higher cooling capacities than that, the High Power Cold Gun can be used. Size-wise, it’s identical to the Cold Gun, but it generates twice the Cold Gun’s flow of cold air.
Mini Cooler (left) and Cold Gun (right).

One of the main advantages of using these Vortex Tube products with the pre-set higher cold fractions is the prevention of freeze-up…while the cold air generated is usually just a little below 32F (0C), ambient conditions in the areas where they’re used typically add enough heat to prevent mass freezing of any moisture condensed in the cooling process. A number of applications, however, do indeed call for much colder air flow than this, and for those, we’ve got the Adjustable Spot Cooler:

EXAIR Adjustable Spot Coolers can generate temperatures as low as -30°F (-34°C) instantly, and on demand.

Their versatility makes them a great “utility player” – when very cold air (well below zero) is needed, the Temperature Control Knob is turned counterclockwise. If another application calls for higher flow (like the Mini Coolers or Cold Guns), it can be turned clockwise for instant adjustment of flow and temperature.

Adjustable Spot Cooler Systems are available with Single or Dual Point Cold Air Hose Kits, and come with three Generators: 15 SCFM (installed), 25 SCFM, and 30 SCFM, to select the compressed air consumption, and hence, the overall flow range.

If you’ve got a spot cooling application, EXAIR Corporation has a Vortex Tube solution for you. Give me a call; let’s talk cold air!.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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