360° Air Wipe Comparison for Extrusion, Hose, Cable, Pipe and Wire Blowoff or Cooling

When it comes to blowing off extrusions, cables, pipe, tubing, hose, or wire, the EXAIR Super Air Wipe is an ideal product that often stands alone in this field. From time to time I will receive a call asking about a block style blowoff for wire or cabling, maybe even small extrusion, and the Super Air Wipe is always there to provide a true 360° blowoff compared to what the customer is used to.

See, the block style blowoffs are similar to the SAW in they both offer a clamshell design that will open and close into place around the product to prevent the user from having to “thread the needle”.  Also, they both operate off compressed air. The means by which they deliver the air is where the stark contrast in performance begins.

First, let us take a look at how these block style blowoffs deliver the air to the product being blown off. Generally, inside of these, there are a couple holes on each half of the block that are drilled at an angle to deliver the air onto the surface of the product. These block style products have to be kept fairly close in diameter to the product so that the air contacts the surfaces and they are for the most part offered in smaller sizes only.

Now, how does the Super Air Wipe deliver the air to the product being blown off?  The air enters (1) into an internal chamber that fills (2) and then dispurses through a continuous gap (3) on each half of the wipe that is set by a shim. The shim can be interchanged with different thicknesses to give a course adjustment to the volumetric flow of air. The air then follows the Coanda profile (4) of the Super Air Wipe to maximize entrained air (5) and exits at a 60° included angle (6) to impact the surface of the part at a full 360°.

Stock Super Air Wipe Product OfferingBlock Style air wipes also have a tendency to operate very loudly, often exceeding 90 dBA and more. This will affects personnel directly and can also affect their communication when attending to a processing line.  Super Air Wipes operate at 82 dBA with 5″ and smaller diameters. Up to 89 dBA for diameterss from 6″-11″.

The Super Air Wipe is available in eleven sizes from stock in aluminum (up to 11″ dia.) while the stainless steel configurations are available in five sizes from stock (up to 4″ dia.).  If aluminum or stainless steel don’t fit the requirements of an application, custom sizes and materials are always available with short lead times.

Tight-fitting locations are ideal for a Super Air Wipe install.

If you notice that the block style air blowoff is leaving streaks or maybe the physical space requirements of the block are too much to fit into your production line, please contact an Application Engineer and let us help you determine which Super Air Wipe is going to be right for your needs.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

 

Bifurcation Of Air – The Wonders of Science That Is The Vortex Tube

EXAIR has provided the benefits of vortex tube technology to the industrial world since 1983. Prior to that, French scientist George Ranque wrote about his discovery in 1928 calling it the tube tourbillion. But it wasn’t until German physicist Rudolf Hilsch’s research paper in 1945 on the wirbelrorhr or whirling tube, that the vortex tube entered the minds of commercial engineers. Nearly 60 years later, EXAIR is a leading provider for cooling products utilizing vortex tube technology.

More than 2,000 BTU/hr in the palm of your hand!

EXAIR Vortex Tubes produce a cold air stream down to -50° F and are a low cost, reliable, maintenance-free (there are no moving parts!) solution to a variety of spot cooling applications. These applications span a wide variety of industries and include cooling of electronic controls, soldered parts, machining operations, heat seals, environmental chambers, and gas samples. We’re always finding compelling new cooling opportunities for the vortex tubes.

How a Vortex Tube Works

So how does it produce the cooling stream? Compressed air is plumbed into the side port of the Vortex Tube where it is ejected tangentially into the internal chamber where the generator is located. The air begins flowing around the generator and spinning up to 1 million RPM toward the hot end (right side in the animation above) of the tube, where some hot air escapes through a control valve. Still spinning, the remaining air is forced back through the middle of the outer vortex. Through a process of conservation of angular momentum, the inner stream loses some kinetic energy in the form of HEAT to the outer stream and exits the vortex tube as COLD air on the other side.

The adjustable control valve adjusts what’s known as the cold fraction. Opening the valve reduces the cold air temperature and also the cold airflow volume. One can achieve the maximum refrigeration (an optimum combination of temperature and volume of flow) around an 80% cold fraction. EXAIR publishes performance charts in our catalog and online to help you dial into the right setting for your application, and you can always contact a real, live, Application Engineer to walk you through it.

EXAIR manufactures its vortex tubes of stainless steel for resistance to corrosion and oxidation. They come in small, medium and large sizes that consume from 2 to 150 SCFM and offer from 135 to 10,200 BTU/hr cooling capacity. Each size can generate several different flow rates, dictated by a small but key part called the generator. That generator can be changed out to increase or decrease the flow rate.

While operation and setup of an EXAIR Vortex Tube are easy, its performance will begin to  decrease with back pressure on the cold or hot air exhaust of over 3 PSIG. This is a key  when delivering the cold or hot airflow through tubes or pipes. They must be sized to minimize or eliminate back pressure.

The Vortex Tube is integrated into a variety of EXAIR products for specific applications, like the Adjustable Spot Cooler, the Mini Cooler, the Cold Gun Aircoolant System and our family of Cabinet Cooler Systems.

If you would like to discuss your next cooling application, please contact an Application Engineer directly and let our team lead you to the most efficient solution on the market.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Turn It Off: Saving Compressed Air The Easy Way

A major benefit to utilizing compressed air is the speed at which it can be shut off and re-energized for use – in fact, this can be done instantaneously. Shutting down the supply of compressed air to an application while it is not needed can drastically reduce the compressed air consumption of the process. This is an easy remedy that can produce significant savings.

Think about a place where you have a compressed air blow off with spaces between the parts or dwell times in conveyor travel. What about break times, do operators continue to keep the air on when they leave for a break or even worse, for the day?

Step number four in EXAIR’s Six Steps to Optimization is:

A simple manual ball valve and a responsible operator can provide savings at every opportunity to shut down the airflow. But an automated solution is a no-brainer and can provide significant savings.

Quarter Turn Ball Valves are low-maintenance and easy to install/use.

For a more automated approach, you can add a solenoid valve that would tie into your existing PLC or e-stop circuit, into your compressed air supply lines to aid in turning the compressed air on and off.

For an automated on/off solution can be found by using the EXAIR EFC (Electronic Flow Control). The EFC is made to accept 110V or 220V AC, and convert it to 24V DC to operate a sensor, timer, and solenoid valve. Its multiple operating modes allow you delay on, delay-off, and delay on/off among others. The operating mode can then be set to the specific time necessary for a successful application.

The spaces between parts can be turned into money saved. Every time you reach the end of a batch run, the EFC can turn the air off. You can also add solenoid valves and run them from your machine controls. If the machine is off, or the conveyor has stopped – close the solenoid valve and save the air. The modes are all defined in the video below.

So, take a look, or even better a listen, around the plant and see what you can find that could benefit from turning the air off; even if it is just for a moment it will help put money back into your bottom line.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Pressure – Absolute, Gauge, and Units of Both

Compressed air is a common utility used throughout industrial facilities and it has to be measured like any other utility in order to know just how much a facility is using. When dealing with compressed air a common unit of measurement that readily comes up is psi, pound-force per square inch. This unit of measure is one of the most basic units used to measure pressure in the compressed air industry. There are other means to measure this though, so let’s discover the difference.

Again, the pressure is a force distributed over an area, the Earth’s atmosphere has pressure, if it didn’t we would all balloon up like the Violet from Willy Wonka, just without eating some prototype gum causing internal pressure. PSIA is a unit of measure that is relative to a full vacuum. It is pounds per square inch absolute (PSIA). The absolute pressure is calculated as the sum of the gauge pressure plus the atmospheric pressure. If you were to travel into space, the atmospheric pressure would be absolute zero which is actually a vacuum. There is nothing pushing from the outside in so the inside pushes out, hence the ballooning.

The atmospheric pressure on earth is based on sea level. This is 14.7 pounds per square inch absolute pressure. This pressure will change along with the weather and the altitude at which the measurement is taken.

So how do we get to the pressure that is displayed on a pressure gauge?  When shown open to room air, my pressure gauge reads zero psi. Well, that is zero psi gauge, this already has the atmosphere showing. It is not showing the Absolute pressure, it is showing the pressure relative to atmospheric conditions. This is going back to the fact that gauge pressure is the summation of absolute pressure and atmospheric conditions, for sea level on earth that is 14.7 psia. So how do we increase this and get the gauge to read higher levels?

We compress the air the gauge is measuring, whether it is using a screw compressor, dual-stage piston compressor, single-cylinder, or any other type of compressor, it is compressing the ambient, atmospheric air. Some materials do not like being compressed. Air, however, reacts well to being compressed and turns into a form of stored energy that gets used throughout industrial facilities.  By compressing the air, we effectively take the air from atmospheric conditions and squeeze it down into a storage tank or piping where it is stored until it is used. Because the air is being compressed you can fit larger volumes (cubic feet or cubic meters) into a smaller area. This is the stored energy, that air that is compressed always wants to expand back out to ambient conditions. Perhaps this video below will help, it shows the GREAT Julius Sumner Miller explaining atmospheric pressure, lack of it, and when you add to it.

Lastly, no matter where you are, there is a scientific unit that can express atmospheric pressure, compressed air pressure, or even lack of pressure which are vacuum levels. To convert between these scientific units, some math calculations are needed. While the video below is no Julius Sumner Miller, it does a great job walking through many of the units we deal with daily here at EXAIR.

 

If you want to discuss pressures, atmospheric pressure, how fast the air expands from your engineered nozzle to atmospheric, why all the moisture in the air compresses with it, and how to keep it out of your process, contact an application engineer and we will be glad to walk through the applications and explanations with you.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

1 – Willy Wonka & the Chocolate Factory – Violet Blows Up Like a Blueberry Scene (7/10) | Movieclips, Movieclips, retrieved from https://youtu.be/8Yqw_f26SvM

2 – Lesson 10 – Atmospheric Pressure – Properties of Gases – Demonstrations in Physics,  Julius Sumner Miller, Retrieved from https://www.youtube.com/watch?v=P3qcAZrNC18

3 – Pressure Units and Pressure Unit Conversion Explained, Chem Academy, retrieve from https://www.youtube.com/watch?v=2rNs0VMiHNw