The History of the Man Behind the Friendly Little Demon

James Clerk Maxwell was born in Edinburgh Scotland on June 13, 1831 and from the age of three years old he was described as have an innate sense of inquisitiveness. In 1839 at the young age of 8 years old James’ mother passed away from abdominal cancer which put the boy’s father and father’s sister-in-law in charge of his schooling. In February of 1842 James’ father took him to see Robert Davidson’s demonstration of electric propulsion and magnetic force; little did he know that this event would strongly impact on his future.

Fascinated with geometry from an early age James would go on to rediscover the regular polyhedron before he was instructed. At the age of 13 James’ would go on to win the schools mathematical medal and first prize in both English and Poetry.

Later in his life James would go on to calculate and discover the relationship between light, electricity, and magnetism. This discovery would lay the ground work for Albert Einstein’s Special Theory of Relativity. Einstein later credit Maxwell for laying the ground work and said his work was “the most profound and the most fruitful that physics has experienced since the time of Newton.”. James Maxwell’s work would literally lay the ground work for launching the world into the nuclear age.

Starting in the year 1859 Maxwell would begin developing the theory of the distribution of velocities in particles of gas, which was later generalized by Ludwig Boltzmann in the formula called the Maxwell-Boltzmann distribution. In his kinetic theory, it is stated that temperature and heat involve only molecular movement. Eventually his work in thermodynamics would lead him to a though experiment that would hypothetically violate the second law of thermodynamics, because the total entropy of the two gases would decrease without applying any work. His description of the experiment is as follows:

…if we conceive of a being whose faculties are so sharpened that he can follow every molecule in its course, such a being, whose attributes are as essentially finite as our own, would be able to do what is impossible to us. For we have seen that molecules in a vessel full of air at uniform temperature are moving with velocities by no means uniform, though the mean velocity of any great number of them, arbitrarily selected, is almost exactly uniform. Now let us suppose that such a vessel is divided into two portions, A and B, by a division in which there is a small hole, and that a being, who can see the individual molecules, opens and closes this hole, so as to allow only the swifter molecules to pass from A to B, and only the slower molecules to pass from B to A. He will thus, without expenditure of work, raise the temperature of B and lower that of A, in contradiction to the second law of thermodynamics.

Here at EXAIR we are very familiar with Maxwell’s “friendly little demon” that can separate gases into a cold and hot stream. His thought experiment, although unproven in his life time, did come to fruition with the introduction of the Vortex Tube.

Vortex Tube a.k.a Maxwell’s Demon

With his birthday being last weekend I propose that we raise a glass and tip our hats to a brilliant man and strive to remember the brilliant ideas that he gave us.

If you have any questions or want more information on EXAIR’s Cabinet Coolers or like products. Give us a call, we have a team of application engineers ready to answer your questions and recommend a solution for your applications.

Cody Biehle
Application Engineer
EXAIR Corporation
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Non Hazardous Purge Cabinet Cooler Systems

Last fall, when our youngest “flew the coop” and moved into a dormitory to begin his college experience, my lovely bride and I also embarked upon an exciting adventure: finding, purchasing, and moving in to our “empty nest” dream house.  While packing up the contents of the house where we had raised a United States Marine AND a hippie college student, I moved my trusty laptop from its perch on a desk in a dark basement corner, where it had resided, in that one spot, for more than a couple years.

As I was looking for its carrying case, I noticed the fan grill was almost completely obscured with more than a couple years’ worth of environmental contamination (or dust).  I vacuumed out the grill, but wondered how much more environmental contamination (dust) had made its way into the deep recesses of the laptop…and more importantly, what might it be doing to the sensitive electronics inside my trusty internet browsing device?

If a computer’s fan in a residential environment can get this dusty, imagine how much worse a control panel on a factory floor can get.

I know I’m not telling you anything you don’t already know, but electronics and dust don’t mix.  We have this conversation a LOT with callers inquiring about our Cabinet Cooler Systems.  The protection they offer against environmental contamination is integral with the protection they offer against heat.  In the panel cooling market, our Cabinet Cooler Systems are unique in that respect: a total protection solution.

When properly installed on a sealed enclosure, the only thing the inside of that enclosure is ever exposed to is cold, clean, moisture free air.  But what if the enclosure can’t be completely sealed?  One option is to use a Continuous Operation Cabinet Cooler System.  It works just as the name implies:  cold air is continuously flowing into the enclosure, creating a constant purge flow…if that cold air is blowing out of any openings in the enclosure, there’s no way for environmental contamination to get in.  Problem solved.

Well…almost.  Something else I’m sure you already know is, compressed air is costly.  Organizations like the Compressed Air & Gas Institute (CAGI) and the Compressed Air Challenge (CAC), who are devoted to optimizing industrial use of compressed air, have lists of “inappropriate uses of compressed air”, and panel cooling is on that list…EXCEPT when they’re thermostatically controlled.  At EXAIR, we couldn’t agree more, and if a caller asks any of us Application Engineers about a Continuous Operation Cabinet Cooler System, they’re inviting us in to a conversation about that.

Sometimes, the initial question is cost…well, we have to pay for the components that make up the Thermostat Controls, so we ask our customers who want those products to as well.   A quick conversation about the operating cost of continuous operation vs thermostat control is usually all that’s required in those cases.

Other times, a panel that can’t be sealed is installed in a particularly dusty or dirty environment, and they want the continuous flow of cold air, as described above, to keep those contaminants out.  A Continuous Operation Cabinet Cooler System will, of course, do that.  But EXAIR wants you to get the most out of your compressed air use, so we developed a “best of both worlds” solution: Non-Hazardous Purge Cabinet Cooler Systems.  Here’s how they work:

  • Based on a few key pieces of data that you can submit in our Cabinet Cooler Systems Sizing Guide, we’ll specify the appropriate Cabinet Cooler System to manage that heat load.
  • The system will be thermostatically controlled: a bimetallic Thermostat, mounted inside the panel, will open and close the Solenoid Valve plumbed in the compressed air supply to operate the Cabinet Cooler as needed to maintain temperature inside the panel.
  • The Solenoid Valve is modified to pass a small amount of air flow (1 SCFM) even when it’s closed.  This saves you from using the full rated air consumption of the Cabinet Cooler when cold air isn’t required, and still maintains enough purge air flow to prevent environmental contaminants from entering a less-than-ideally-sealed enclosure.

Whatever you do, DON’T do THIS to your panel.

The Non-Hazardous Purge option is just one way that EXAIR Corporation can help you address specific environmental challenges that may be presented in electrical and electronic panel cooling applications.  If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Opportunities To Save On Compressed Air

Even casual readers of the EXAIR Blog will notice that we Application Engineers are keen on efficiency.  I just counted sixty-seven blogs on the site that discuss our Six Steps To Optimizing Your Compressed Air System.  Some offer a broad overview, while others focus on specific steps, and one tells us more than I ever expected to learn from an engineering blog about…Bigfoot.

I’m going to take a different tack here – no; I’m not going to write about the Yeti or the Loch Ness Monster, but I may try to get the Jersey Devil into a blog someday.  I will, instead, relate some real-life examples of the success of implementing each individual step.  It’s important to note here that they don’t have to be done in order, or even in total, to achieve impressive results.

  1. Measure the air consumption to find sources that use a lot of compressed air.  Like I just said, you don’t HAVE to do these steps in order, but if you DO intend to pursue a comprehensive solution, this is where you want to start.  The facility manager of a large manufacturing plant did just that when a series of Digital Flowmeters were installed in the branch lines to their production cells.  By comparing their present-day actual usage to the original design specifications, they noticed that usage in a certain cell (due to business growth) had increased to the point that they had raised the main header pressure in an attempt to keep point-of-use pressures at proper levels.  By installing a larger diameter branch line to that cell, they were able to reduce main header pressure from 120psig to 100psig, reducing their compressors’ energy usage (and their share of the electric bill) by 10%.
    Summing Remote Display (left) for remote indication and totalizing data. USB Data Logger takes data from the Digital Flowmeter to your computer and outputs to its own software (shown above) or Microsoft Excel.
  2. Find and fix the leaks in your compressed air system.  A factory once noticed they were losing header pressure overnight, when they were closed.  Using an Ultrasonic Leak Detector, they identified some small leaks that nobody thought were all that significant…until they did the math, comparing previous compressed air consumption (including those leaks) to that of their “new and improved” leak-free system.  Fixing those leaks saved them just over a million cubic feet of compressed air a year.  The exact figure was 1,062,500 cubic feet, annually.  I know this is accurate, because it was us.

  3. Upgrade your blowoff, cooling and drying operations using engineered compressed air products.  This could apply to almost every single order we process, so I’m going use an example from my first day here.  During training, I learned that a customer had recently called to get air consumption data on some EXAIR products they were going to implement as part of an upgrade that was also going to involve purchasing a new compressor.  Their main usage was a number of open-end blow offs that ran continuously.  After outfitting those with Model 1100 Super Air Nozzles and Model 9040 Foot Pedals (so the operators had simple, hands-free control over blowing cycles), they not only found they didn’t need a new air compressor, but were able to shut down an existing 50HP air compressor.
    Foot Pedal + Air Hose + Super Air Nozzle = Instant Blow Off System!
  4. Turn off the compressed air when it isn’t in use.  There are a few methods for doing this, and they’re all pretty easy:
    • Good.  Manual shutoff valves (1/4 turn ball valves are great for this) can be used by mindful operators to shut off compressed air use between production cycles, during lunch breaks, and (I hope this is patently obvious to the most casual observer) at closing time.  I’ve talked to users about doing this, but I don’t have any great success stories about this method.  It relies on someone’s memory in knowing when to operate the valve…and nobody’s remembered to call me back with a full report either.
    • Better.  If you only need air blowing while a machine is running,
      EXAIR stocks Solenoid Valves in a variety of sizes & voltages

      most any qualified industrial electrician can wire a solenoid valve into the on/off control of the machine.  Better yet, if the system has programmable logic control (PLC), it can be used to open & shut that same solenoid valve, to effect blow off only as needed.  I worked with an automotive parts manufacturer who had a robot passing parts between a pair of Model 110042 42″ Aluminum Super Air Knives.  They had taken care to accurately position the Air Knives, and program the robot’s movement & speed, to optimize blow off…but the Air Knives were running continuously.  After a brief conversation with the line foreman, they bought and installed a Model 9065 1 NPT 24VDC Solenoid Valve and “told” the PLC to turn air flow on as the robotic arm approached the Air Knives, and turn it off right after the part had passed through.
    • Best.  In the absence of programmable logic, the simplicity of the EXAIR EFC Electronic Flow Control just can’t be beat.  It’s a standalone system that consists of a Solenoid Valve that’s operated by a photoelectric sensor and controlled by a programmable timer.  Whether it’s a tenth of a second, or a few minutes, waste is waste, and it adds up.  Consider this application writeup from our Optimization Products catalog section:
      Turning air off when it’s not needed adds up, even if it’s just for a few seconds at a time.

       

       

       

  5. Use intermediate storage of compressed air near the point of use.  If
    Prevent intermittent demands from starving other loads with intermediate storage.

    compressed air is used in any sizable amount in your facility, odds are, you have a compressor room.  If it’s done right, this is a good thing for your compressor, but it CAN present some challenges for distribution over large areas.  A user of EXAIR Super Ion Air Knives, for example, installed a Model 9500-60 Receiver Tank in an area some distance from the compressor room to maintain higher air pressure than line loss (from the length of the header pipe) was allowing.  Their other option was to increase their overall header pressure; this allowed them to maintain current costs…increasing system pressure by 2psi equates to a 1% increase in compressed air generation costs.
  6. Control the air pressure at the point of use to minimize air consumption.  In addition to controlling OVERALL compressed air system pressure (see examples 1 & 5 above), using Pressure Regulators to control the supply pressure to specific compressed air operated products will save you money too…the lower the supply pressure, the lower the consumption.  A Model 1101 1/4 MNPT Super Air Nozzle, for example, uses 14 SCFM when supplied at 80psig…that’s where we publish its performance, because that’ll give a good, strong blast of air, suitable for a wide range of typical industrial air blowing applications. A tube manufacturer once replaced two open blow off devices that used about 38 SCFM each with Model 1101’s.  Even though that cut their air consumption by more than half, they were able to cut it even further by regulating the supply pressure to 56psig…that’s the pressure at which they could still get the job done consistently, resulting in ANOTHER 25% reduction in compressed air consumption.

If you’d like to find out more about any, or all, of the Six Steps To Optimizing Your Compressed Air System, give me a call.

Russ Bowman, CCASS

 

 

 

Application Engineer
EXAIR Corporation
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Round and Round They Go…. Rotary Compressors: How They Work

Positive-displacement and dynamic displacement compressors are the two high level principles for the generation of compressed air or gas. Positive displacement types are the most common found in industrial facilities. These units draw ambient air into a chamber which it seals off and then works to compress and squeeze it down into a smaller volume. The air is then discharged into the outlet system of the compressor. Out of the many types of positive displacement compressors, today we are going to discuss the rotary style positive displacement air compressors.

1 – Simplified Rotary Vane Compressor



These are available in both lubricant-free as well as lubricant-injected versions. The main function of the compressor is the same, both have two inter-meshing rotors what pull air into the inlet port and then after the rotational processing of the compressor the air is discharged through a discharge port. The in between of the ports is where the important information lies. The air after being sucked into the inlet gets pulled in between two lobes and the stator. As the air is being trapped the space between the lobes becomes increasingly smaller, thus increasing the pressure of the air transferring it to the discharge port.

The lubricated versions will often help to dissipate the heat that is created as the air is being compressed. This lubricant is then possible to transfer into the compressed air stream and must be removed before a point of use product if lubricant-free air is needed for the process. These compressors rank amongst the lower efficiencies in the positive displacement air compressors.

If you are visual learner, feel free to take a few minutes for the video below.

2 – Rotary Compressor Operation


If you would like to discuss the way to get the most out of your compressor, no matter the type, contact an Application Engineer and let us help you determine the most efficient way to use the air effectively.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

1 – Rotary vane.png – R. Castelnuovo, 10/20/2005 – retrieve from https://commons.wikimedia.org/wiki/File:Rotary_vane.png

2 – Rotary compressor operation – HVACRinfo.com – 8/1/2016 – retrieved from https://www.youtube.com/watch?v=fxDEK3Ymx30