Month: August 2015

Ion Air Cannon

Published on by John BallLeave a comment

Generally in the winter time, we see an increase in production issues due to static. When the ambient air becomes drier, static ions build more easily on the surface. For this application, the customer was drying a wood based compost with compressed air. His compressed air system used a heated desiccant dryer to remove the moisture to a dew point of -40 deg. F (-40 deg. C). (That means the compressed air system would not see any water unless the temperature was below -40 deg.) He would blow the very dry air into the bed to remove any moisture. This would make the compost very light and reduce decomposing.

Ion Air Cannon
Ion Air Cannon

The problem occurred during shipment. He would convey the compost up a conveyor belt to a chute. The chute had a line to direct the compost inside a rail car. Because of the non-conductive material of the conveyor belt and the extremely dry material of wood, a large amount of static was being generated. With like charges repelling each other, it would create a bridge in the chute, causing it to plug and backup. My suggestion was to use our Super Ion Air Cannon. It would remove the static charges that was being generated, and also create a small positive pressure to keep the compost moving. With the amount of material that he was conveying, he installed 4 Super Ion Air Cannons for each chute. The problem was solved and the operation was not hindered. If you have any issues with your system, you can contact one of our Application Engineers to see if we can help at 800-903-9247.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: twitter.com/exair_jb

More on Vortex Tubes: Understanding Cold Fractions

Published on by Lee EvansLeave a comment
vortex tube
An EXAIR Vortex Tube

I had a conversation today through our online chat feature with a customer in the Middle East who needed a bit more understanding about Vortex Tubes.  The cooling power and instantaneous ability of a Vortex Tube offers ways to remove heat from applications, but the way the Vortex Tube works was a little misunderstood.  So, we went over the basics.

A Vortex Tube transforms a compressed air supply into a stream of hot and cold air.  As the compressed air enters into the Vortex Tube, it passes through a generator which causes the air to spin.  The airstream spins down the length of the Vortex Tube until it reaches a “brake”, whereupon it changes directions and begins spinning inside of itself, giving off energy in the form of heat.  The result is a stream of cold air at one end of the Vortex Tube, and a stream of hot air at the other.

But how can we adjust the flows and temperatures?

Adjusting the flow and cold air temperature from a Vortex Tube is as simple as turning the adjustment valve at the hot end of the unit.  This valve controls the “cold fraction” of the Vortex Tube, or, to put it more simply, the amount of air which will exit the unit at the cold end.

EXAIR Vortex Tube Performance Chart
EXAIR Vortex Tube Performance Chart

For example, if we were to set a Vortex Tube to an 80% cold fraction, 80% of the air consumed by the Vortex Tube would exhaust through the cold end of the unit.  If we take the same Vortex Tube and establish a 60% cold fraction, 60% of the consumed air will exhaust through the cold end of the unit.

Why is this important?

The cold fraction is important because at various cold fractions we will product varying temperature drops, even at the same operating pressure.  So, in the example above, if we have a Vortex Tube operating at 7 BARG, set to an 80% cold fraction, we can expect a temperature drop of 30°C (54°F), relative to the temperature of the incoming compressed air.

This means that if our compressed air temperature is 25°C (77°F), we will have an outlet temperature of -5°C (23°F).  If we take the same air supply and reduce the cold fraction to 60%, we will have a temperature drop of 48°C (86°F).

The caveat here is that when we reduce the air temperature, we also reduce the flow.  So, the colder the air temperature from the Vortex Tube cold end, the lower the volume of cold air.

When determining if a Vortex Tube is right for an application, it is important to consider all the variables (operating pressure, compressed air temperature, cold fraction, required cooling) when making a model number selection.

If you have any questions or concerns when considering a Vortex Tube, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Big Or Small, We’ve Got ‘Em All! Vortex Tubes, That Is

Published on by Russ BowmanLeave a comment

A couple of weeks ago, I wrote about using large Vortex Tubes for freeze sealing/plugging of pipes. Even though they’re our LARGE Vortex Tubes, they’re still WAY smaller than the liquid nitrogen rigs that are also prevalent for this application. Smaller, in this case, means easier to handle and quicker to set up (and break down.)

So, that’s a case where a smaller device is used to do the same job. Today, I wanted to examine the different sizes of Vortex Tubes that we offer, when the job itself is what’s changing in size.

The Large Vortex Tubes are specified when a high flow of cold air is needed. Like the aforementioned freeze seals. Or this one, published in our catalog:

This is a typical application for a Large Vortex Tube.
This is a typical application for a Large Vortex Tube.

Our Medium Vortex Tubes are the most popular – there are ten to choose from, depending on the cold air flow rate and temperature you’re looking for. These can produce temperatures as cold as -40°F (-40°C) when set to a 20% Cold Fraction (which is the percentage of total supply air that’s directed to the cold end) and cold air flows as high as 32 SCFM when set to an 80% Cold Fraction, which will produce a cold air temperature of about 20°F (-7°C). Some common uses are cooling ultrasonic welds and brazed joints.

The Medium Vortex Tubes are so popular, in fact, that they’re incorporated into our Adjustable Spot Cooler and Cold Gun Systems. They come ready-to-go with mufflers, cold air hose kits, and magnetic bases, so they couldn’t be easier to use.

The Small Vortex Tubes are great when very low flows are needed, or if compressed air supply is limited. These are specified for much smaller applications, like cooling the needle of a sewing machine, small drill bits, etc. You can also get one with a cold air hose & magnetic base…that’s the Mini Cooler System.

Another advantage that makes the Vortex Tubes a great choice for cold air production is their consistency and dependability. If you supply one with clean, dry air, it’ll operate just about indefinitely, maintenance free. And if you need a constant supply of air as a certain temperature, say, for testing a thermostat or temperature switch, a Vortex Tube is exactly what you’re looking for: the only things that’ll change the cold air temperature are the compressed air supply temperature & pressure…assuming you don’t change the Cold Fraction yourself, as shown here:

If you’ve got an application requiring cold air flow, give us a call. We’re eager to help!

Russ Bowman
Application Engineer
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Hard Work Leads To Good Results

Published on by exaircorpLeave a comment

A few months ago I wrote a blog titled Great Team Make-up about being an assistant coach for my oldest son’s youth football team. I take pride in the opportunity to work with young kids in teaching them the value of teamwork and showing them when you work hard, the results will speak for themselves. It’s not just about winning or losing, but rather learning to listen, be respectful (win or lose) and growing as a player.

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6 rushing touchdowns in a single game? I’ll take it.

The first 3 practices were no pads, no contact so these days were spent conditioning and learning offensive and defensive positions. (or as the kids called it – “The most boring thing EVER!”). We have been in full contact practice for the last 5 weeks and it’s pretty cool to see how much the kids have learned in such a short time. We’ve had a couple scrimmages but this past weekend we had our first real game.

As both teams took the field you could see the nervousness of the players and the anticipation of the coaches on both sides. When you start playing at 9:00 AM, with dew on the ground, it’s kind of difficult for 5-7 year olds to hold on to a wet football. The game started pretty slow and by halftime it was only a 6 point difference. The second half was much different, our team really started to “click” on offense. We had some great blocking up front coupled with some determined running backs and scored consecutive 65, 52 and 49 yard rushing touchdowns. On the opposite side, our defense tightened up and held their opponent to only 1 score in the second half leading to a 38-16 victory! It was awesome to see our group of young men (who were very recently mere 5-7 year-olds trying to hang on to the wet ball) so excited about winning and to see their effort pay off. As coaches we were equally satisfied that not only were we able to get the win, but to see these incredible kids execute what they’ve learned in practice and transition that to the game.

Here at EXAIR, our commitment to be the best in the industry is best reflected in the solutions we provide for our customer’s needs. Two of our most informative tools are the Application Database and Case Study Library. The Application Database is over 1000 applications in a problem/solution format, detailing various industrial processes and the EXAIR product solution. Whether you’re dealing with a static electricity issue, needing to provide cooling to critical instruments, drying product, looking to convey media or just needing to provide blowoff, chances are you will find the information you are looking for.

The Case Study Library is a database where you can see quantifiable benefits or ROI of installing EXAIR products. We typically show improvements in dollar savings, compressed air savings, production increases, noise exposure decreases and safety improvements focused on reaching important OSHA standards. We are always seeking new case studies and can offer an incentive or SWAG in return for providing us the details on your application. A great place to start is with our Efficiency Lab, where we can actually gather the details for you.

Some examples of the information we are looking to obtain:

  • A decrease in air consumption
  • Improved safety
  • Lowering noise level
  • Reducing the amount of rejects – increasing production

Give us a call at 800-903-9247 to team up with one of our application engineers to see how we can coach you to a win in your facility.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

Harvard Stadium 57240 image courtesy of Ted Eytan, Creative Commons License