The Case For Refrigerant Compressed Air Dryer Systems

No matter what your use of compressed air entails, moisture is very likely an issue.  Air compressors pressurize air that they pull in straight from the environment and most of the time, there’s at least a little humidity involved.  Now, if you have an industrial air compressor, it’s also very likely that it was supplied with a dryer, for this very reason.

There are different types of dryer systems, depending on your requirements.

For practical purposes, “dryness” of compressed air is really its dew point.  That’s the temperature at which water vapor in the air will condense into liquid water…which is when it becomes the aforementioned issue in your compressed air applications.  This can cause rust in air cylinders, motors, tools, etc.  It can be detrimental to blow offs – anything in your compressed air flow is going to get on the surface of whatever you’re blowing onto.  It can lead to freezing in Vortex Tube applications when a low enough cold air temperature is produced.

Some very stringent applications (food & pharma folks, I’m looking at you) call for VERY low dew points…ISO 8673.1 (food and pharma folks, you know what I’m talking about) calls for a dew point of -40°F (-40°C) as well as very fine particulate filtration specs.  As a consumer who likes high levels of sanitary practice for the foods and medicines I put in my body, I’m EXTREMELY appreciative of this.  The dryer systems that are capable of low dew points like this operate as physical filtration (membrane types) or effect a chemical reaction to absorb or adsorb water (desiccant or deliquescent types.)  These are all on the higher ends of purchase price, operating costs, and maintenance levels.

For many industrial and commercial applications, though, you really just need a dew point that’s below the lowest expected ambient temperature in which you’ll be operating your compressed air products & devices.  Refrigerant type air dryers are ideal for this.  They tend to be on the less expensive side for purchase, operating, and maintenance costs.  They typically produce air with a dew point of 35-40°F (~2-5°C) but if that’s all you need, they let you avoid the expense of the ones that produce those much lower dew points.  Here’s how they work:

  • Red-to-orange arrows: hot air straight from the compressor gets cooled by some really cold air (more on that in a moment.)
  • Orange-to-blue arrows: the air is now cooled further by refrigerant…this causes a good amount of the water vapor in it to condense, where it leaves the system through the trap & drain (black arrow.)
  • Blue-to-purple arrows: Remember when the hot air straight from the compressor got cooled by really cold air? This is it. Now it flows into the compressed air header, with a sufficiently low dew point, for use in the plant.

Non-cycling refrigerant dryers are good for systems that operate with a continuous air demand.  They have minimal dew point swings, but, because they run all the time, they’re not always ideal when your compressed air is not in continuous use.  For those situations, cycling refrigerant dryers will conserve energy…also called mass thermal dryers, they use the refrigerant to cool a solution (usually glycol) to cool the incoming air.  Once the glycol reaches a certain temperature, the system turns on and runs until the solution (thermal mass) is cooled, then it turns off.  Because of this, a cycling system’s operating time (and cost) closely follows the compressor’s load – so if your compressor runs 70% of the time, a cycling dryer will cost 30% less to operate than a non-cycling one.

EXAIR Corporation wants you to get the most out of your compressed air system.  If you have questions, I’d love to hear from you.

Russ Bowman
Application Engineer
EXAIR Corporation
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Video: EXAIR Drum Vacs Selection For Solid Materials

EXAIR Corporation has engineered compressed air solutions for Industrial Housekeeping…among them, a full line of drum mounted vacuums for dry/solids cleanup.

If you’d like to find out more, please give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Upgrade Blowoff Applications with Engineered Products to Increase Safety and Efficiency

At EXAIR, it’s our business to make sure that you get the most out of your compressed air system.  We’ve got a Six Step plan to help you do just that, and one of those steps is the topic of today’s blog:

We have a couple of ways to help with step #1.  You can use a Digital Flowmeter to measure your total compressed air usage, and take advantage of our Efficiency Lab service to determine the consumption of individual compressed air devices that may be running up the total.  Based on our performance tests of those devices, we can recommend suitable EXAIR Intelligent Compressed Air Products to replace them with, along with the expected reductions in air consumption & noise levels…quieter is always better too.

We’re going to skip right over Step #2…just for now…but if you can’t wait, click on the picture above for more on finding & fixing leaks.

Once you get our recommended replacements in (I mean, why wouldn’t you?), they’re going to be part of your compressed air system, so naturally, we want to make sure you get the most out of them as well.  Key considerations are suitable supply lines, and proper installation.

In the case of a Super Air Nozzle or Air Jet, these are oftentimes one and the same.  They’re all small enough, and lightweight enough, to be adequately supported by compressed air piping (assuming the piping is adequately supported,) metal tubing (via a compression fitting adapter,) or even mounting solutions like our Stay Set Hoses.

Just a few ideas for installing an EXAIR Super Air Nozzle

Sometimes, though, you need a firm, vibration-resistant mounting…that’s where we recommend our Swivel Fittings.  A hex retainer tightly locks the ball in position, but allows for easy repositioning when loosened.  They come in standard NPT sizes from 1″ NPT down to 1/8″ NPT, and we even have them for the M4, M5, and M6 metric threads for our Atto, Pico, and Nano Super Air Nozzles.

Typical threaded fittings are limited in the angles you can achieve. EXAIR Swivel Fittings provide 50° of adjustability.

Even a highly efficient blow off needs to be aimed well in order to do its job well.  If you’d like to discuss how to get the most out of your compressed air system – or our products – give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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The Case For Desiccant Compressed Air Dryers

Most people are familiar with desiccant from the small packets we find enclosed with a new pair of shoes, in a bag of beef jerky, or in some medication bottles.  These packets almost always say “Do Not Eat,” and I get that for the ones in the beef jerky or the pill bottles, but I just don’t understand why they put it on the desiccant packets bound for a shoe box…

Anyway, desiccant (in MUCH larger volumes than the household examples above) are also used to get water vapor out of compressed air.  Desiccant dryers are popular because they’re effective and reliable.  The most common design consists of two vertical tanks, or towers, filled with desiccant media – usually activated alumina or silica gel.

These materials are prone to adsorption (similar to absorption, only it’s a physical process instead of a chemical one) which means they’re good at trapping, and holding, water.  In operation, one of these towers has air coming in it straight from the compressor (after it’s become pressurized, remember, it still has just as much water vapor in it as it did when it was drawn in…up to 5% of the total gas volume.)

When that tower’s desiccant has adsorbed water vapor for long enough (it’s usually controlled by a timer,) the dryer controls will port the air through the other tower, and commence a restoration cycle on the first tower.  So, one is always working, and the other is always getting ready for work.

There are three methods by which the desiccant media can be restored:

  • Regenerative Desiccant Dryers send a purge flow of dry air (fresh from the operating tower’s discharge) through the off-line tower’s desiccant bed.  This dry air flow reverses the adsorption process, and carries the water away as it’s exhausted from the dryer.  This is simple and effective, but it DOES use a certain amount of your compressed air.
  • Heat Of Compression Desiccant Dryers use the heat from pressurized air straight from the compressor(s).  This hot air is directed through one tower, where it removes moisture from the desiccant.  It then flows through a heat exchanger where it’s cooled, condensing the moisture, before it flows through the other tower to remove any remaining moisture.  This method doesn’t add to your compressed air usage, but it only works with oil-free compressors.
  • The third method uses a hot air blower to flow heated air through the off-line desiccant bed.  It’s similar to the Regenerative type, but it doesn’t use compressed air.  However, they DO require a certain amount of wattage for the heater…remember, electricity isn’t cheap either.

As an EXAIR Application Engineer, it’s my job to help you get the most out of our products, and your compressed air system.  If you have questions about compressed air, call me.

Russ Bowman
Application Engineer
EXAIR Corporation
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EXAIR Reversible Drum Vac Fills A 55 Gallon Drum in 90 Seconds Flat, And Empties It Just As Fast

There are a few ways to get the liquid out of a drum:

  • You can use a pump.  Some pumps are even made to mount straight onto the lid of the drum.
  • You can siphon the liquid out, if you can get the drum higher than where you want to put the liquid.  And if you have the time.
  • You can turn the drum over.  I used to do field service in chemical plants…some of them had drum handlers on fork trucks that could pick up and tilt the drum to pour the liquid out.  Some of them pushed the drum over and simply let the liquid spill into a pit or below-grade sump.

But pumps break down.  Siphoning is finicky and slow.  I’m loath to knock the skills of the fork truck operator that can pour out a drum like a sommelier pours a fine wine.  And I’ll never forget the first time I saw an operator half-roll/half-dance a drum to the edge of that pit and let the liquid dump as he dropped it precisely where he wanted it…however, even in the context of the inner recesses of a chemical plant, it was simple, but inelegant.

EXAIR has an engineered solution that preserves the simplicity, though: the Reversible Drum Vac.  Thread the standpipe into the bung connection and the RDV itself into the vent, and that drum is now a two-way pumping system, able to be emptied via a 10 foot long Vacuum Hose in as little as a minute and a half.  Turn the knob on the RDV to switch modes, and you can fill that same drum just as fast.

With a simple turn of the knob, the Reversible Drum Vac can fill or empty a 55 gallon drum in 90 seconds!

 

 

 

 

 

 

The EXAIR Reversible Drum Vac Systems come with a variety of configurations and options:

  • Made to fit an existing 30, 55, or 110 closed top steel drum in good condition.
  • Mini Reversible Drum Vac System comes with a 5 gallon drum.
  • Deluxe Systems add a Drum Dolly and a set of tools.
  • Premium Systems add a drum (30, 55, or 110 gallon,) an upgrade to Heavy Duty Aluminum Tools, and a 20ft compressed air supply hose with shutoff valve and pressure gauge.
  • High Lift Reversible Drum Vacs generate a suction head of 180″H2O for maximum lift.  They’re also specified for higher viscosity liquids.

Below is a great video that showcases just how easy it is to from installing the Reversible Drum Vac to using the Reversible Drum Vac and just how fast the RDV operates.

If you’re looking for a fluid handling solution for liquids in drums, give me a call and we’ll talk about which Reversible Drum Vac System is right for you.

Russ Bowman
Application Engineer
EXAIR Corporation
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EXAIR Intelligent Compressed Air Products Are Automation’s Best Friend

For decades, children and adults (really cool ones, anyway) have enjoyed the popular board game, Mouse Trap:

The fun of the game is that it exaggerates the notion of providing an overly complicated solution to a simple problem – a notion made famous by Rube Goldberg, whose namesake machines are as thought-provoking as they are entertaining to watch.

As fun as Rube Goldberg machines are, there are actually ways to engineer something “just enough” – that’s what automation engineers strive to do every day; and EXAIR is here to help.

Probably the most popular feature, for automated applications, of engineered compressed air products is instantaneous performance.  For example:

  • When an electric motor-powered blower is used for a blow off, cooling, or drying application, there’s going to be a “ramp-up” period to reach full rated flow.  Not so with an EXAIR Intelligent Compressed Air Product, like a Super Air Wipe, Super Air Knife, Super Air Nozzle, Super Air Amplifier, etc.  They are generating their rated flow as fast as you can open the supply valve.

    EXAIR Intelligent Compressed Air Products such as (left to right) the Super Air Wipe, Super Air Knife, Super Air Nozzle, and Super Air Amplifier provide instant on/off performance, at rated levels.
  • Likewise, vacuum pumps necessarily take some time to develop their rated vacuum level.  But the venturi in an EXAIR E-Vac Vacuum Generator draws its full rated vacuum flow as soon as the compressed air is turned on.  The peak vacuum level is achieved in the amount of time it takes to pull the air out of the lines or vessel.

    These are all examples of how an E-Vac pick-and-place system is just a solenoid valve away from being an automated process.
  • All EXAIR Atomizing Spray Nozzles can be fitted with a No Drip feature, which allows instant on/off control, simply by opening/closing a valve in the compressed air supply line.  This is often done with a solenoid valve tied in to the machine controls, or with an EXAIR EFC, Electronic Flow Control (more on that in a minute.)  They can handle up to 180 cycles per minute, for quick bursts of atomized mist, on demand.  No other method of liquid flow control can match that kind of performance.

    Fine mist liquid spray, on demand, from an EXAIR No Drip Atomizing Spray Nozzle.
  • EXAIR Spot Cooling Products, Cold Guns, and Cabinet Cooler Systems all use Vortex Tube technology.  This “splits” a supply of compressed air into a hot, and cold air flow.  Unlike refrigerant, chilled water, or cryogenic gas methods, they don’t rely on conduction or convection heat transfer between materials, so cold (and hot) air is produced, at rated flow and temperature, instantly.  They, too, can be turned on & off as often as needed…there are no moving parts to wear or damage.

    The unique phenomenon of the Vortex Tube principle makes cold air instantly for as long – or short – a time as needed.

Automation projects often incorporate existing logic, controls, timers, etc. to actuate the process.  For example, if you wanted to use a Chip Vac to vacuum debris from a chop saw, you can simply wire a solenoid valve into the power switch of the saw…it’ll run while the saw runs, and stop when the saw is turned off.

EXAIR’s award winning EFC Electronic Flow is ready to go, right out of the box.

If there are no existing logic, controls, timers, etc., EXAIR has a solution for those cases too: the EFC Electronic Flow Control.  We have four models to accommodate up to 350 SCFM of compressed air flow – that’s ten feet worth of Super Air Knives.  The EFC consists of a photoelectric sensor that opens/closes a solenoid valve, based on the programming of the integral timer.  It’s a stand alone system that doesn’t require input from, nor is it affected by, any external factors.

Automation projects can get pretty intricate.  EXAIR Intelligent Compressed Air Products are aimed at keeping their involvement as simple as possible.  If you’d like to find out more, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Compressed Air Pressure Regulators Conserve And Protect

Imagine you’re enjoying a nice shower. A cascade of warm water is soothing your body – and spirit – then, someone starts the dishwasher. Or a load of laundry. Or flushes the toilet. Suddenly, the “soothe” turns to “scald” or “freeze,” depending on whether you’ve been robbed of hot, or cold water.  So, what happened?

What happened is, all of those “loads” on your house’s water supply that can ruin your shower experience are controlled by simple on/off valves…they open to permit a certain amount of water FLOW to pass.  When the dishwasher starts, or someone decides to wash a load of whites, the HOT water from your nice warm shower is diverted, leaving a stream of cold water.  When a toilet flushes, or it’s a load of colors, the COLD water is diverted…and that’s not just unpleasant, but downright painful.  Either way, (in my house anyway,) a teenager is getting read the riot act.

The same phenomenon can apply in a compressed air system, if simple flow control valves are used to throttle the appropriate supply of air to a pneumatic device.  If someone, for example, hooks up an air gun to blow off their tools or parts, the valves on EVERYTHING else will need to be opened up some to keep those devices working the same.  In the case of an air gun like this, it usually happens too quick to make the necessary adjustments (by hand) and you’re probably left with a machine tripped off-line, or a ruined part.

Pressure Regulators can prevent this by keeping (or regulating) their downstream pressure to a set value.  If a load elsewhere in the system is activated, the Pressure Regulator opens up, automatically, to keep its output constant.  When that load is secured, the Pressure Regulator closes back down accordingly.  Either way, no single load affects the operation of any others.

That’s only half the value of the use of Pressure Regulators, though.  The other half is, well…the value.  Just looking at a typical function of many EXAIR Intelligent Compressed Air Products – blow off – they’ll all pretty much accomplish the task if you run them, unrestricted, straight off your header.  That’ll give you a good, strong blast of air flow…and it may be more than what’s required, and a waste of good air.  Pressure Regulators will prevent this by allowing you to “dial in” the supply pressure to whatever it takes to get the job done, and no more.

EXAIR offers a range of Pressure Regulators capable of handling air flow of up to 700 SCFM.

Compressed air isn’t free.  Heck, it isn’t even cheap.  Don’t use any more than you have to, and get the most out of what you do use.  Pressure Regulators are one important step in doing this.  If you’d like to talk about optimizing your use of your compressed air system, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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