Month: March 2009

Intermediate Air Storage

Published on by Kirk Edwards2 Comments

Also known as secondary receivers, intermediate air storage can be especially effective when a system has shifting demands or large volume use in a specific area. Intermediate storage is the buffer between a large demand event and the output of your compressor.

Step number five in Six Steps to Optimization is:
1. Measure your air consumption
2. Locate and fix any compressed air leaks in the system
3. Upgrade your end use blow off applications with engineered products
4. Turn off the compressed air when not needed for production
5. Use intermediate storage of compressed air near the point of use
6. Control the pressure at the point of use to minimize consumption

The buffer created by intermediate storage (secondary receiver) prevents pressure fluctuations which may impact other end use operations and affect your end product quality.

An application which is a good fit for a secondary receiver tank is one with a high intermittent demand of compressed air, short duration of this demand, and enough time in between demand events to replenish the receiver pressure without needing additional capacity from the compressor.

A properly outfitted intermediate storage tank includes a check valve to hold pressure and proper volume delivered to the receiver, a valve which allows you to evenly fill the receiver back to its full volume and pressure, a relief valve, and a drain valve to release condensate.

Properly sized and located intermediate storage strategies can greatly improve compressed air system efficiencies. They are easy to use and install and require little maintenance.

Kirk Edwards
Application Engineer
kirkedwards@exair.com

First Response to Grain Avalanche

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I had a first responder contact me for a way to extract a person trapped in grain. On occasion a pile of grain will avalanche. If there is a person at the base of the pile they will be trapped. Even if only buried up to their knees in grain, they cannot extract themselves.

The way they typically extract a victim is to insert a ring around them and shovel the grain out from around them. The ring prevents any grain from filling back in. The problem with shovels is that they have to be extremely careful not to injure the person, and the shoveling can become quite a time consuming process.

What I suggested to them is to use a 2″ Line Vac, Model 6084 to vacuum the grain out.  This not only worked but it was much faster than doing it with a shovel and with no risk to the victim.

Joe Panfalone
Application Engineer
joepanfalone@exair.com

I have a cooling application; I need a Vortex Tube, right?

Published on by Neal Raker4 Comments

We speak to people every day about cooling applications. And the common theme that I can see come through in those conversations is that the average Joe may not understand that you do not always need a Vortex Tube to be effective in a cooling application.

For example, a customer recently asked whether a Vortex Tube could be used to cool a metal sleeve that was induction heated to a relatively low temperature (about 250F) in order to cure a coating that had been applied. Another customer asked about using a Vortex Tube to cool a sheet coming out of a lamination machine. Again, starting temp. was around 300F. The point of cooling in both applications was to get the temperature down to handle-able (about 125F) in as short a time as possible.

You do not need to use a Vortex Tube to cool the targets in these kinds of applications. In fact, due to the shape of the air flow, larger volume flow, and the air temperature (let’s say 80F), there is something better.

 In the case of the induction heated tube, an Air Amplifier worked quite well and did not use as much air as a Vortex Tube to do the job. In the case of the lamination, a 12″ Super Air Knife was able to provide a cool enough and wide enough airflow to bring the temperature down very quickly.

The purpose of a Vortex Tube is to create temperature differential (change). If you already have that temperature differential established between the hot target and the cooling airflow (say from an Air Amplifier blowing 80F air and a target at 300F, a 220F delta T) you only need a large volume of the cooling medium,air, in this case. Which is exactly what Air Amplifiers and Air Knives do, amplify air volume and project it at a target.

The next logical question might be then, “When DO I use a Vortex Tube?” The answer to that question is something I will cover in my blog for next week.

Neal Raker
Application Engineer
nealraker@exair.com

As Spring Approaches, So Do The Weeds

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Ever use a weed eater or weed whacker?  Ever notice that the thing that actually cuts the weeds and grass is not an actual blade, but a piece or two of plastic string, attached to a central spinner?  Well, I got a call last week from a company that extrudes the plastic that is used to make this string, called monofilament. 

They needed a way to dry the 5mm diameter strands of plastic after going through a washing process, before going into an oven to be heated and stretched.  For those of you that are familiar with our products, you are probably already thinking, this is a perfect fit for our 1/2″ Super Air Wipe.  Normally, yes, that would be the best solution.  But, the specifics of this application call for something different.

There are actually 4 strands of plastic on each extrusion machine, spanning a width of only 3″.  Thus, 2pc of a 3″ Super Air Knife, one above and one below the array, is actually a better choice.  There is not sufficient spacing between the strands to use four Super Air Wipes.  But, the spacing is plenty wide enough to allow the air from the air knives to get between the strands and dry them on all sides before going into the oven. 

Even though the most obvious choice was not the best choice in this case, we were still able to provide a solution for the customer.  Not to mention the fact that (4) 1/2″ Super Air Wipes would have been a larger air consumption requirement than (2) 3″ Super Air Knives.  So, sometimes it pays to “think outside the box.”

Emily Mortimer
Application Engineer
emilymortimer@exair.com