Measure Your Facility’s Compressed Air Consumption w/ EXAIR’s Digital Flowmeters

Published on by Tyler DanielLeave a comment

If you’re a follower of the EXAIR Blog, you’re probably well aware that compressed air is the most expensive utility in an industrial environment. The average cost to generate 1000 Standard Cubic Feet of compressed air is $0.25. If you’re familiar with how much air you use on a daily basis, you’ll understand just how quickly that adds up. To make matters worse, many compressed air systems waste significant amounts of compressed air just through leaks. According to the Compressed Air Challenge, a typical plant that has not been well maintained will likely have a leak rate of approximately 20%!! Good luck explaining to your finance department that you’re carelessly wasting 20% of the most expensive utility.
Step 1 of EXAIR’s 6 steps to optimizing your compressed air system, is to measure the air consumption at various points within the facility to find the applications that consume a lot of air.

In order to have an understanding of your compressed air use across various processes and in your entire facility, you have to measure. Without a measurement of usage, there’s no way to determine your actual costs or evaluate opportunities for savings. To do so, EXAIR offers a range of Digital Flowmeters in sizes from as small as ½” Schedule 40 iron pipe and up to 4” Schedule 40 pipe from stock. Larger sizes and pipes calibrated for use on copper or metric pipe are also available.

The Digital Flowmeter provides a digital readout of the exact amount of compressed air being used. Many companies will install the DFM on each major leg of their air distribution system to allow for constant monitoring and provide a benchmark of compressed air usage.

Each Digital Flow Meter has a built-in LED display that provides the volume of air moving through the pipe in SCFM, m3/hr, or m3/min. Customizing the display is simple, using the button on the side of the meter. (3) different display modes are available: Current Rate, Daily Usage, and Cumulative Usage. The 4th option available allows you to change the unit of measure. The process is quite simple and easy:

Two small probes are inserted into holes in the pipe (drill guide kit w/ drill bit included) to detect the airflow. The unit seals to the pipe once the clamps are tightened. (If the DFM ever needs to be removed, EXAIR also offers blocking rings to seal off the holes) No cutting, welding, adjustments or calibrations are ever required.

If you need to export the data to your PC, EXAIR offers a USB Data Logger. Both of these options will allow you to track usage over time and upload that data to an Excel spreadsheet. The meter is offered from stock with 4-20 mA outputs you can use to export into any existing software you may be using, or we offer an optional RS-484 Modbus output as a special (contact EXAIR for more information).

If you’re “flying blind” when it comes to understanding the cost of compressed air in your facility, this is the first step. Contact an EXAIR Application Engineer today to get started. We’ll be happy to help you identify areas where you could take advantage of simple savings.

Tyler Daniel, CCASS

Application Engineer

E-mail: TylerDaniel@EXAIR.com

X: @EXAIR_TD

Controlling Temperature And Flow From A Vortex Tube

Published on by Russ BowmanLeave a comment

The Vortex Tube is among the most fascinating air-operated devices to me. It’s right up there with the pneumatic impact wrench, which is my HIGHLY preferred method of removing (and replacing) a tire on a vehicle. While there are several different types of impact wrenches, they all basically use air pressure to move internal parts in a manner in which they strike (or impact) a rotating element with a socket on the end, resulting in a lot more torque being applied than if it was simply spinning a propeller attached to the shaft.

Vortex Tubes, on the other hand, all work on the same principle, discovered by a French engineer, Georges Ranque, while he was experimenting with a new design of a vacuum pump in 1922. There doesn’t seem to be any record of him completing the work on his newfangled vacuum pump, but he did continue experimenting with this device that made hot air come out one end, and cold air come out the other, getting a patent for it in 1931.

How a Vortex Tube Works: compressed air enters the vortex spin chamber (big blue arrow from above left), where the Generator imparts a spinning motion to it (red ribbon, moving to the right). When the spinning air flow reaches the other end, some of it is forced to change direction and, while still spinning, flow the other way (blue ribbon, moving to the left). The rest exits through the hot valve (represented by the yellow cone). When the spinning air flow changes directions, it gives off energy in the form of heat, causing hot air to exit one way, and cold air to exit the other.

EXAIR offers two series of Vortex Tubes:

  • 32XX series, or Maximum Refrigeration. These make the highest flows of cold air, at temperatures suitable for rapid cooling of warm objects to ambient (or below) temperatures.
  • 34XX series, or Maximum Cold Temperature. These will give you the coldest air possible – as low as minus 50°F – but at lower flows, relative to the 32XX series. I’ll go into more detail on both of these in a minute.
Sub-zero air flow from Model 3408 Vortex Tubes cools & solidifies chocolate in candy molds.

Both of these series consist of Vortex Tubes in three sizes, with multiple models in each size. The difference between the models in each series is the compressed air consumption:

You can control the temperature, and the flows (both hot and cold), of any Vortex Tube in a few different ways:

  • Supply pressure affects the total flow of the two air streams, and the magnitude of the change in temperature. Since higher pressure equals more energy, it stands to reason that, at higher pressures, the hot air will be hotter, and the cold air will be colder.
  • Cold Fraction is the percentage of the compressed air supply that gets directed to the cold end. You can get VERY cold air from a Vortex Tube by setting it to a low cold fraction. This is done by opening the Hot Valve to let more hot air out. That causes the flow rate, and the temperature of the air coming out of the cold end, to drop.
Turning the Hot Valve counterclockwise (blue arrow) lets more hot air out, which lowers the cold air flow, and temperature. Turning it clockwise (red arrow) lets less hot air out, which raises the cold air flow…and temperature.
  • Two types of Generators can be installed in an EXAIR Vortex Tube – these are what determine the series I mentioned above:
    • Type “R” (Maximum Refrigeration) Generators allow for Cold Fraction adjustments from 50-80%. With an air supply pressure of 100psig, the cold air will be 54°F (when set to an 80% Cold Fraction) to 100°F (at a 50% Cold Fraction) lower than the compressed air supply temperature. This makes them suitable for applications where rapid cooling of an object is needed.
    • Type “C” (Maximum Cold Temperature) Generators give you Cold Fraction adjustments from 20-50%. A Vortex Tube with a “C” Generator installed will give you the same 100°F temperature drop as the “R” Generator will at a 50% Cold Fraction, but at a 20% Cold Fraction, it’ll be 123°F colder than the supply. These are used where cooling to temperatures below 0°F is needed.
How to tell which Generator is installed in a Vortex Tube.

If you need to remove & replace a tire, I strongly recommend using a pneumatic impact wrench. If you need to blow cold air for something, I just as strongly recommend using an EXAIR Vortex Tube. Different applications require different series, models, and settings. Give me a call if you’d like to find out which combination of those is right for your application.

Russ Bowman, CCASS

Application Engineer
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EXAIR’s Threaded Line Vacs™

Published on by John BallLeave a comment
Which of these Line Vacs has higher performance? We can’t be sure without checking the generator!

As an Application Engineer, I get the pleasure of speaking to many people about trying to find a safe, simple, long-lasting transfer system to suit their applications.  Plants will have operators that climb steps to dump bags of material into hoppers above, which is a safety concern.  They might need a compact way to remove scrap from their process.  Or they have budgetary constraints to convey material from point A to point B. If your company has to tackle any of these issues, EXAIR may have a solution for you.  Our Line Vacs™ can attach easily to standard hoses, pipes, or sanitary flanges.   These inexpensive conveyors are designed to make conveyance safer and ergonomically better for your operators.  

Line Vacs use compressed air to generate a vacuum by a Venturi effect.  This unique design generates high velocity to create a powerful vacuum on one side.  Once the material reaches the throat area of the Line Vac, the compressed air will carry the product the rest of the way.  We can reach horizontal distances up to 100 feet (30 meters) and vertical heights up to 20 feet (6 meters).  EXAIR manufactures a variety of Line Vacs in different sizes, styles, and materials.  In this blog, I will cover the Threaded Line Vacs. 

As mentioned above, EXAIR has a variety of connection types.  The Threaded Line Vacs are designed to convert standard pipes into powerful conveying systems.  We offer them as a standard Line Vac in aluminum, 303 stainless steel, and 316 stainless steel.  They range from 3/8” NPT up to 3” NPT.  We also have the Heavy Duty Threaded Line Vacs that are engineered to move abrasive materials with an increased conveyance rate.  They range from ¾” NPT up to 3” NPT.  The construction is made from a hardened alloy material to resist wear from abrasive bulk products like steel parts, sand, glass, ceramic, sandblasting material, etc.  With the compressed air inlet on the side, the Threaded Line Vacs can fit in line with a conveying pipe. 

To make these Line Vacs more practical, EXAIR sells them in a kit format which includes a properly sized filter, regulator, and a mounting bracket.  This adds value to mounting, controlling, and protecting the Line Vac for years to come.  The Line Vacs have no moving parts and are a great product to use in rugged industrial applications.  You will not have to worry about any motors or bearings prematurely wearing out.

For our U.S. and Canadian customers, we are running a promotional ad.  You will receive a 2” Flat Super Air Nozzle, a $92.00 value, for free from now until the end of October 2024 with a qualified Line Vac purchase online.  If you would like to discuss your conveying application further, please contact an Application Engineer at EXAIR.  We may have a simple solution for you.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

“Other” Uses For Vacuum Generators

Published on by Brian FarnoLeave a comment

Okay. Throughout our catalog and most of my training, many moons ago, we always stuck to using the E Vac Vacuum Generators as pick and place type units. Hook them up with some suction cups and you can have some fun. However, this isn’t all they can be used for. In fact, I blogged about it over a decade ago not being used for a pick and place operation. Rather, I used it to pull a steady vacuum on a hydraulic brake system in order to pull the fluid through the lines.

My E-Vac Brake Bleeder Setup

Today, I want to show you another trick that I am almost certain I saw when I was a kid on Mr. Wizard. I saw this in High School, learning from one of my amazing educators in the Science department, and then again in college taking basic Chemistry courses. The trick is maybe not something that you would use regularly, but it is a great visualization for something that may help some DIY’ers and even some industrial engineers. So what is the process exactly? Well, it is using a vacuum to “boil” water, except we aren’t really boiling the water, it just appears that way.

That’s right, in this video you can see I have a very small E-Vac Vacuum Generator connected to a glass jar with some water in it. Now there is some condensation in the jar from the water being warmer than the environment we were in. As I energize the E-Vac, you will see the operating pressure go up on the gauge to the right, and you will see the pressure in the jar go down on the vacuum gauge to the left. You can also see just how quickly the small E-Vac removes all the air from the chamber and then begins to build the vacuum, effectively pulling the gas from water, making it appear as though it is boiling due to a temperature increase. Instead, it is actually “de-gassing” the water and removing the oxygen.

This same process can be used in molding operations, epoxy resin processes, and even off-gassing operations. If you can get the surface or container into a vacuum condition, then an Inline E Vac or Adjustable E Vac can be used to evacuate the gases from the fluid within the chamber or area. This makes them more conducive for use without bubbles forming during the curing phase. The size of the E Vac needed for this will be determined by the size of the area and that is exactly what our Application Engineers are here to help with.

If you would like to discuss an off-the-wall idea or de-gassing, feel free to contact an Application Engineer today.

Brian Farno, MBA – CCASS Application Engineer

BrianFarno@EXAIR.com
@EXAIR_BF