Tag: electric

Static and Variance

Published on by Brian FarnoLeave a comment

Okay, folks, it is time we seriously discuss how dry it is here in the MidWest right now and how much static there is anywhere we go. The dry air is the lack of moisture due to heat being used inside facilities, and thus, the static ramps up. If you didn’t understand much of those statements then it is okay, we have a whitepaper that covers the basics. The seriousness of the static in my home has reached critical mass. We are past the funny shocks and hair standing on the end humor side of static. We have reached a critical mass where it is no longer funny, my coffee is being affected by the ambient level of static charge.

That’s right, the coffee grinder I received for Christmas is riddled with static. Now, it is still functioning, thank goodness for that. The container that houses the fresh ground, the nectar of the gods making crushed beans, is made of polycarbonate material and is prime to hold a static charge. As the dry coffee beans are ground into obliteration there is a tremendous amount of friction which causes a very high charge on the ground bean discharge that goes into a very dry non-conductive container. This means the grinds all pile up and then also cling to every single surface on the interior of the small container. That’s fine, it still does not affect the performance of the grinder. Then, when I open the lid there is a detachment that happens and a small amount of that highly charged ground bean will start to dance all over the surfaces of the container, including outside of it and onto the counter. The end result is I have to constantly wipe up coffee grinds and I am wasting the grinds that give me the caffeine I intend to consume.

The dilemma here is that I don’t want to run compressed air into my kitchen, already have one project going on in the house. Secondly, my wife would not think it would be as entertaining as I would. So, I need a non-compressed air-assisted static eliminator that can plug straight into a voltage available here in the US, and let’s face it, coffee is a global consumption so 120 VAC and 230 VAC would be preferred. Enter, the VariStat Benchtop Ionizer.

The Varistat would easily mount to the wall over my coffee generation station and could be adjusted from a gentle breeze to where it doesn’t disturb the coffee grinds all the way up to a forceful blast in case the need would arise. I could also vary the balance of the unit to meet the atmospheric and surface conditions of the container.

Okay, so I’m probably not going to buy a Varistat Benchtop Ionizer and mount it to my kitchen wall. I would easily recommend it to any kind of hopper loader or regrind operation where the static is causing the materials to cling to the containers or causing nuisance shocks. This unit is easily sat on a bench top or mounted to a wall or ceiling over a hopper or workstation. Thanks to the operation of standard 120 VAC or 230 VAC it can function nearly anywhere in the world that has electricity.

If you would like to discuss coffee, what my favorite roasts are, or more importantly how can we make this work in our building, just let me know if you have some questions and we will get back to you quickly.

Brian Farno, MBA – CCASS Application Engineer

BrianFarno@EXAIR.com
@EXAIR_BF

Air Compressors: Maintenance and Optimization

Published on by John BallLeave a comment

In one of my previous jobs, I was responsible for the operation of the facility, and one of my biggest jobs was the operation of our air compressor.  Like with many industries, the compressor system is the lifeblood of the company.  If the compressor fails, the whole facility will stop.  In this blog, I will share some maintenance items and schedules for air compressors.

Because the cost to make compressed air is expensive, the compressed air system is considered to be a fourth utility.  With such an important investment, you would like to keep it operating as long and efficiently as possible.  To do this, it is recommended to get your air compressor a “checkup” every so often.  I will cover some important items to check.  Depending on the size and type, some items may or may not apply.  But please, always check with the manufacturer of your air compressor.

Intake filter: The intake filter is used to clean the air that is being drawn into the air compressor.  Better filtration results in less debris getting into your system.  Particles can damage the air pump mechanisms over time as well as plug filters and heat exchangers downstream.  If they are not properly monitored and cleaned, the air flow can be restricted.  This will cause the compressor motor to operate harder and hotter.

Compressor Oil: This would be for flooded screws and reciprocating compressors that use oil to lubricate the bearings and sleeves in the air pump.  Most systems have an oil sight to verify levels.  The oil can also be checked for acidity, which will tell the degree at which the oil is breaking down.  Just like the motor oil in your car, you will have to replace it after so many hours of operation.

Belts & couplings: These items transmit the power from the motor to the air pump.  Check their alignment, condition, and tension (belts only) as specified by the manufacturer.  You should have spares on hand in case of any failures.

Electric Motors: A mechanical device that turns electric energy into rotational energy.  It is the main component that uses a lot of energy to make compressed air.  So, some checks are required to foresee any potential issues and major shutdowns.  For the windings inside, the resistance should be measured with a multi-meter, and it should fall within the motor’s specifications.  Another check should be on the start capacitor.  The start capacitor stores energy to give the motor a powerful boost to get it turning.  One other item is the centrifugal switch.  Just like the name states, it will disconnect the start capacitor when the motor starts spinning.  One other item for large electric motors is the phase converter.  These are typically capacitors, and they are designed to keep the direction of three-phase motors going in the correct rotation.  Both types of capacitors can be checked with a multi-meter.

Air/Oil Separators: This filter removes as much oil from the compressed air before it travels downstream.  It returns the oil back to the sump of the air compressor.  If the Air/Oil Separator builds too much pressure drop, excess oil can travel downstream.  Not only will the air pump lose the required oil level, but it will affect the performance of downstream parts like air dryers and after-coolers.  Also, the pressure drop is a waste and can rob your air system of workable energy. 

Internal filters: Many air compressors will come with an attached refrigerated air dryer.   With this type of air compressor, they will place coalescing filters to remove any residual oil.  These filters should be checked for pressure drop.  If the pressure drop gets too high, then it will rob your compressed air system of pressure, and you will not get the required performance.  Some filters come with a pressure drop indicator which can help you to determine the time to change the element.   

Unloader valve: When the air compressor unloads, this valve helps to remove any of the compressed air that is trapped in the cavity.  When the air compressor restarts, it does not have to “work” against this air pressure.  If they do not fully unload, the air compressor will have to work harder to start, wasting energy.

Preventative maintenance is very important.  As for a schedule, I created a rough sequence to check, change, or clean certain items that are important to your air compressor.  You should also check with your local compressor representative for a more detailed maintenance schedule.

Daily:

  • After stopping, remove any condensate from the receiver tank.
  • Check the oil level.

Monthly:

  • Inspect the cooling fins on the air pumps.  Clean if necessary
  • Inspect the oil cooler. Clean if necessary

Quarterly:

  • Inspect the inlet air filter.  Clean or replace if necessary.
  • Check the belt for tension and cracks.  Tighten or replace.
  • Check differential pressure indicators on outlet compressed air filters.
  • Ohm check on the electric motor

Yearly:

  • Replace Air Inlet Filter
  • Replace the air-oil separator
  • Test safety valves and un-loader valve
  • Replace compressed air filters
  • Change oil
  • Grease bearings if required

Keeping your air compressor running optimally is very important for pneumatic operations.  But there is much more than an air compressor in your system.  To help, there are steps that can be used on the demand side.  EXAIR created a Webinar – “Optimizing Your Compressed Air System In 6 Simple Steps”.  With this combination, you can keep a healthy compressed air system.  You can always contact an Application Engineer at EXAIR to see how much money can be saved by energy reduction, safety, and monitoring.  

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

Image courtesy of Compressor1 – Creative commons license

Critical Equipment Needs Reliable Heat Protection

Published on by Russ BowmanLeave a comment

Electricity and water don’t mix. Electrical and electronic components don’t like many contaminants that can be found in industrial settings, either. Exposure to moisture or dirt are surefire ways to “let the smoke out” – it can be just as bad as letting them overheat. Once that’s happened, replacement of the failed components is usually the only option. THAT can get expensive not only in the cost of the component, but also in the downtime waiting for it to come in…which can be a REAL problem if they’re not in stock.

Luckily, there’s no shortage of cooling devices for electrical panels. They all have certain areas/situations where they’ll work just fine, but most have areas/situations that can cause real problems:

Panel air conditioners work a lot like the a/c in your home or office, and if you’ve ever used window a/c units, they work EXACTLY like those. Since they cool the air as they recirculate it through the space, they have filters to catch any particulate. If the panel isn’t sealed tightly, this filter may very well require regular attention. They also use air from the surrounding environment to condense the hot refrigerant gas:

Evaporator: heat from inside air is transferred to a refrigerant, flashing it from liquid to gas.
Compressor: pressurizes low pressure refrigerant gas.
Condenser: transfers heat from hot, high pressure refrigerant gas to outside air.
Expansion valve: lowers pressure (and temperature) of condensed refrigerant, sending it to the evaporator to continue the heat transfer cycle.

If the condenser coils are exposed to contaminants (dust, oil, chemical vapors, etc.), they’ll be subject to fouling & corrosion, making panel air conditioners more prone to failure in more aggressive environments. Also, since they use air from the environment as a heat sink for the refrigerant, their cooling capacity is inversely affected by the ambient temperature.

Heat Pipe systems also use refrigerant, but they don’t have any moving parts to wear. Since they don’t have a compressor or expansion valve, though, they’re incapable of cooling the panel below ambient temperature. The evaporator fins or coils are also still subject to environmental contamination, so they have the same limitations as a panel a/c system…and are further limited in hot spaces.

Panel fans are easily the least expensive cooling method. They’re usually fitted with filters for the outside air that they move through the enclosure. Like heat pipes, they can’t cool the enclosure to a temperature below ambient for the area, and the filters are still subject to clogging from airborne particulate, and since those filters have to be coarse enough for the fan’s cooling air flow, smaller particulate can still make it inside the panel….along with any vapors or gases that could condense, or worse, corrode components inside the panel. If the fan on a home computer can get as dusty as the one in the photo to the left, imagine how much worse the one on a control panel on a factory floor can get.

Liquid to Air coolers use liquid – the most common being chilled water – for cold fluid flow through coils inside the panel to remove heat, which is then transferred to ambient through a refrigerant chiller, or a fan & radiator. The inside coils are subject to fouling and condensation if the panel isn’t sealed tightly, and the refrigerant chiller has the same limitations as a panel a/c unit. If it uses a fan & radiator, it (like panel fans or heat pipes) can’t cool the panel to less than ambient temperature in the area.

EXAIR Cabinet Coolers have no moving parts and use compressed air as the sole cooling medium, so they’re not affected at all by environmental conditions. When they’re properly installed on a sealed enclosure, the only thing the inside of the enclosure ever sees is clean, cold, moisture-free air. Wherever your panel is, and regardless of the environment, EXAIR has a wide selection of cooling capacities, features, and materials of construction. Consider:

  • Cooling capacities from 275 to 5,600 Btu/hr. Call me if your heat load is outside this range…we can look at customized solutions too.
  • NEMA 12 (IP54), NEMA 4, or NEMA 4X (IP66) ratings.
  • Thermostat Control – Standard, or Electronic Temperature Control.
  • Non-Hazardous Purge for contaminant exclusion on less-than-ideally sealed enclosures.
  • High Temperature models for ambient temperatures from 125°F (52°C) to 200°F (93°C).
  • Side Mount Kits where space is limited above the panel.
  • 316SS construction for particularly aggressive environments.
  • UL Classified systems for hazardous locations: Our HazLoc systems are approved for Class I Div 1, Class II Div 1 & Class III areas, and ATEX systems are approved for Zones 2 & 22.
Inside, outdoors, high temperature, dirt/dust/humidity, corrosive and classified environments are no problem for EXAIR Cabinet Cooler Systems

If you need heat protection for electrical/electronic panels, EXAIR has solutions. To find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
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Non Hazardous Purge Cabinet Cooler Systems

Published on by Russ BowmanLeave a comment

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
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