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
Visit us on the Web
Follow me on Twitter
Like us on Facebook

 

Six Steps to Optimization, Step 4 – Turn Off Your Compressed Air When Not in Use

Step 4 of the Six Steps To Optimizing Your Compressed Air System is ‘Turn off the compressed air when it isn’t in use.’  Click on the link above for a good summary of the all the steps.

6 Steps from Catalog

Two basic methods to set up a compressed air operation for turning off is the ball valve and the solenoid valve. Of the two, the simplest is the ball valve. It is a quarter turn, manually operated valve that stops the flow of the compressed air when the handle is rotated 90°. It is best for operations where the compressed air is needed for a long duration, and shut off is infrequent, such as at the end of the shift.

manual_valves (2)
Manual Ball Valves, from 1/4 NPT to 1-1/4 NPT

The solenoid valve offers more flexibility. A solenoid valve is an electro-mechanical valve that uses electric current to produce a magnetic field which moves a mechanism to control the flow of air. A solenoid can be wired to simple push button station, for turning the air flow on and off – similar to the manual valve in that relies on a person to remember to turn the air off when not needed.

wa_solvalv
A Wide Array of Solenoid Valve Offerings for Various Flows and Voltage Requirements

Another way to use a solenoid valve is to wire it in conjunction with a PLC or machine control system. Through simple programming, the solenoid can be set to turn on/off whenever certain parameters are met. An example would be to energize the solenoid to supply an air knife when a conveyor is running to blow off parts when they pass under. When the conveyor is stopped, the solenoid would close and the air would stop blowing.

The EXAIR EFC (Electronic Flow Control) is a stand alone solenoid control system. The EFC combines a photoelectric sensor with a timer control that turns the air on and off based on the presence (or lack of presence) of an object in front of the sensor. There are 8 programmable on/off modes for different process requirements. The use of the EFC provides the highest level of compressed air usage control. The air is turned on only when an object is present and turned off when the object has passed by.

efcapp
EFC Used To Control Bin Blow Off Operation

By turning off the air when not needed, whether by a manual ball valve, a solenoid valve integrated into the PLC machine control or the EXAIR EFC, compressed air usage will be minimized and operation costs reduced.

If you have questions about the EFC, solenoid valves, ball valves or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
Send me an email
Find us on the Web 
Like us on Facebook
Twitter: @EXAIR_BB

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
Visit us on the Web
Follow me on Twitter
Like us on Facebook

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
Visit us on the Web
Follow me on Twitter
Like us on Facebook

Candy Producer Saves $4600 in Compressed Air with EXAIR’s EFC

A few months ago, I took a phone call from a manufacturing engineer who worked at a large candy production facility here in the United States. Extra chocolate was dripping out of the candy molds onto the conveyor belt below.  Within a few hours the belt was dirty enough they would have to stop the line and clean the residual chocolate off the belt. 

The best solution I found was a 72” 316 Stainless Steel Super Air Knife. It worked great when powered at 60 psig inlet pressure. The laminar flow of the Super Air Knife was perfectly suited for this application.  The knife was mounted between the mold and the belt to help solidify and blowoff the excess drips of chocolate. There was one drawback, the Super Air Knife was not needed to blow the belt continuously and the continuous demand was not desirable during peak production.

The simple solution for this was the EXAIR Electronic Flow Control, the EFC minimizes compressed air use by turning off the air when a sensor is triggered. Since there was a 4.5-minute time gap between each mold set this was a great solution. When the photoelectric eye saw a mold, it then told the solenoid valve to open and supply the knife with compressed air for 30 seconds while the mold was open and the excess chocolate would be dripping. See the Savings calculations below;

efcapp

Without using the EFC

(* Using $ 0.25 per 1000 SCFM used)

  • 72” Super Ion Air Knife = 165.6 SCFM @ 60 PSIG
  • 165.6 SCFM x 60 minutes x $ 0.25 / 1000 SCFM = $ 2.48 per hour
  • $ 2.48 per hour x 8 hours = $ 19.84 per 8-hour day
  • $ 19.84 x 5 days = $ 99.20 per work week
  • $ 99.20 per week x 52 weeks =$5,158.40 per work year without the EFC control

 

With the EFC installed (turning the compressed air off for 4 minutes 30 seconds with a 30 second on time = 6 minutes/hour compressed air usage)

  • 165.6 SCFM x 6 minute x $ 0.25 / 1000 SCFM = $ 0.25 per hour
  • $ 0.25 per hour x 8 hours = $ 2.00 per 8-hour day
  • $ 2.00 x 5 days = $ 10.00 per work week
  • $ 10.00 per week x 52 weeks = $520.00 per work year with the EFC control 

$ 5,158.40 per year (w/o EFC) – $ 520.00 per year (w/ EFC) = $4,638.40 projected savings per year by incorporating the EFC.

EFC287x250

This example illustrates, clearly, why choosing the EFC is a good idea. It has the ability to keep compressed air costs to a minimum and saves compressed air for use within other processes around the plant. With this type of compressed air savings, the unit would pay for itself in less than 3 months.

If you would like to see how we might be able to improve your process or provide a solution for valuable savings, please contact one of our Application Engineers.

Jordan Shouse
Application Engineer
Send me an email
Find us on the Web 
Like us on Facebook
Twitter: @EXAIR_JS

 

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
Visit us on the Web
Follow me on Twitter
Like us on Facebook

Cabinet Cooling with Thermostat Control and ETC

An EXAIR Cabinet Cooler® System with either the Thermostat Control or the Electronic Temperature Control (ETC) option includes a temperature measuring device that is used to control the operation of the Cabinet Cooler System to maintain the set-point temperature.Thermostat and ETC

For most industrial enclosure cooling applications, a temperature of 95°F (35°C) is sufficient to be below the rated maximum operating temperature of the electrical components inside the cabinet. EXAIR Thermostats are preset to 95°F (35°C) and are adjustable. Maintaining the cabinet at 95°F (35°C) will keep the electronics cool and provide long life and reduced failures due to excessive heat. But if 95°F (35°C) is good, why not cool the cabinet to 70°F (21.1°C)?

When cooling an enclosure to a lower temperature, two things come into play that need to be considered. First, the amount of external heat load (the heat load caused by the environment) is increased. Using the table below, we can see the effect of cooling a cabinet to the lower temperature. For a 48″ x 36″ x 18″ cabinet, the surface area is 45 ft² (4.18 m²). If the ambient temperature is 105°F (40.55°C), we can find from the table the factors of 3.3 BTU/hr/ft² and 13.8 BTU/hr/ft² for the Temperature Differentials of 10°F (5.55°C) and 35°F (19.45°C). The factor is multiplied by the cabinet surface area to get the external heat load. The heat load values calculate to be 148.5 BTU/hr and 621 BTU/hr, a difference of 472.5 BTU/hr (119.1 kcal/hr)

External Heat Load

The extra external heat load of 472.5 BTU/hr (119.1 kcal/hr) will require the Cabinet Cooler System to run more often and for a longer duration to effectively remove the additional heat. This will increase, unnecessarily, the operating costs of the cooling operation.

The other factor that must be considered when cooling an enclosure to a lower temperature is that the Cabinet Cooler cooling capacity rating is effected. I won’t go into the detail in this blog, but note that a 1,000 BTU/hr Cabinet Cooler (rated for 95°F (35°C cooling) working to cool a cabinet down to 70°F (21.1°C) instead of 95°, has a reduced cooling capacity of 695 BTU/hr (174 kcal/hr).  The reduction is due to the cold air being able to absorb less heat as the air rises in temperature to 70°F instead of 95°F.

In summary – operating a Cabinet Cooler System at 95°F (35°C) provides a level cooling that will keep sensitive electronics cool and trouble-free, while using the least amount of compressed air possible.  Cooling to below this level will result in higher operation costs.

If you have questions about Cabinet Cooler Systems or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
Send me an email
Find us on the Web 
Like us on Facebook
Twitter: @EXAIR_BB