CFM, ICFM, ACFM, SCFM: Why so many volumetric flow rates?

Air Compressor

Flow rate is the quantity of material that is moved per unit of time.  Generally, the quantity of material can be expressed as a mass or a volume.  For example, mass flow rates are in units of pounds per minute or kilograms per hour.  Volumetric flow rates are stated in cubic feet per minute or liters per hour.  The trick begins when volumetric flow rates are used for a compressible gas.  In this blog, I will go over the various acronyms and the reasons behind them.

What acronyms will be covered?

CFM – Cubic Feet per Minute

SCFM – Standard Cubic Feet per Minute

ACFM – Actual Cubic Feet per Minute

ICFM – Inlet Cubic Feet per Minute

The volumetric component of the flow rate is CFM or Cubic Feet per Minute.  This term is commonly used for rating air compressors.  From history of air compressors, they could calculate the volume of air being drawn into the air compressor by the size of cylinder.  With the volume of the compression chamber and the rotations per minute of the motor, RPM, they could calculate the volumetric air flows.  As conditions change like altitude, temperature, and relative humidity, the value of CFM changes.  To better clarify these conditions, compressor manufacturers decided to add terms with definition.  (For your information, air compressors still use CFM as a unit of air flow, but now this is defined at standard temperature and pressure).

The first letter in front of CFM above now defines the conditions in which the volumetric air flow is being measured.  This is important for comparing pneumatic components or for properly sizing pneumatic systems. Volume is measured with three areas: temperature, pressure, and relative humidity.  We can see this in the Ideal Gas Law: P * V = n * R * T or Equation 1:

V = n * R * T / P

V – Volume

n – Number of molecules of gas

R – Universal Gas Constant

T – Absolute Temperature

P – Absolute Pressure

The volume of air can change in reference to pressure, temperature, and the number of molecules.  Where is the relative humidity?  This would be referenced in the “n” term.  The more water vapor, or higher RH value, the less molecules of air is in a given volume.

SCFM is the most commonly used term, and it can be the most confusing.  The idea of this volumetric air flow is to set a reference point for comparisons.  So, no matter the pressure, temperature, or relative humidity, the volumetric air flows can be compared to each other at that reference point.  There have been many debates about an appropriate standard temperature and pressure, or STP.  But as long as you use the same reference point, then you can still compare the results.  In this blog, I will be using the Compressed Air and Gas Institute, CAGI, reference where the “Standard” condition is at 14.5 PSIA, 68 deg. F, and 0% RH.  Since we have a reference point, we still need to know the actual conditions for comparison.  It is like having a location of a restaurant as a reference, but if you do not know your current location, you cannot reach it.   Similarly, we are “moving” the air from its actual condition to a reference or “Standard” condition.  We will need to know where the air began in order to reach that reference point.  We will talk more about this later in this blog.

ACFM is the volumetric air flow under actual conditions.  This is actually the “true” flow rate.  Even though this term is hardly used, there are reasons why we will need to know this value.  We can size an air compressor that is not at “Standard” conditions, and we can use this value to calculate velocity and pressure drop in a system.  We can correlate between SCFM and ACFM with Equation 2:

ACFM = SCFM * [Pstd / (Pact – Psat Φ)] * (Tact / Tstd)

Where:

ACFM = Actual Cubic Feet per Minute
SCFM = Standard Cubic Feet per Minute
Pstd = standard absolute air pressure (psia)
Pact = absolute pressure at the actual level (psia)
Psat = saturation pressure at the actual temperature (psi)
Φ = Actual relative humidity
Tact = Actual ambient air temperature (oR)
Tstd = Standard temperature (oR)

ICFM is one of the newest terms in the history of air compressors.  This is where devices are added to the inlet of an air compressor, affecting the flow conditions.  If you have a blower on the inlet of an air compressor, the volumetric flow rate changes as the pressure and temperature rises at the “Inlet”.  If a filter is used, then the pressure drop will decrease the incoming pressure at the “Inlet”.  These devices that affect the volumetric flow rate for an air compressor should be considered.  The equation to relate the ACFM to ICFM is with Equation 3:

ICFM = ACFM * (Pact / Pf) * (Tf / Tact)

Where:

ICFM = Inlet Cubic Feet Per Minute

Pf  = Pressure after filter or inlet equipment (PSIA)

Tf = Temperature after filter or inlet equipment (°R)

Examples of these different types of flow rates can be found here in this EXAIR blog by Tyler Daniel.

To expand on my explanation above about SCFM and ACFM, a technical question comes up about the pressure when using SCFM.  The reference point of 14.5 PSIA is in the definition of SCFM.  Remember, this is only a reference point.  The starting location is actually required.  This would be the ACFM value where the air values are true and actual.  As an example, two air nozzles are rated for 60 SCFM.  An EXAIR Super Air Nozzle, model 1106, is cataloged at 80 PSIG, and a competitor is cataloged at 60 PSIG.  By comparison, they look like they use the same amount of compressed air, but actually they do not.  To simplify Equation 2, we can compare the two nozzles at the same temperature and RH at 68 Deg. F and 0% RH respectively.  This equation can be reduced to Equation 4:

ACFM = SCFM * 14.5 / (P + 14.5)

@60 PSIG Competitor:

ACFM = 60 SCFM * 14.5 PSIA/ (60 PSIG + 14.5 PSIA)

= 11.7 ACFM

@80 PSIG EXAIR Super Air Nozzle:

ACFM = 60 SCFM * 14.5 PSIA / (80 PSIG + 14.5PSIA)

= 9.2 ACFM

Even though the SCFM is the same amount, you are actually using 21% more air with the competitive nozzle that was reported at 60 PSIG.  So, when it comes to rating compressed air products or air compressors, always ask the conditions of pressure, temperature and RH.  The more you know about volumetric flow rates, the better decision that you can make.  If you need help, you can always contact our application engineers at EXAIR.

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

 

EXAIR Super Air Amplifiers Compared to Fans

Super Air Amplifier

EXAIR Super Air Amplifiers and fans are designed to move air.  Fans use motors and blades to push the air toward the target.  There are two types, centrifugal fans and axial fans.  Centrifugal fans are also called blowers or “squirrel” cages.  The air enters into the side of the fan and is redirected 90 degrees to the outlet.  The axial fans are box fans, ceiling fans, and industrial fans.  The motor and spindle are attached to blades.  The air enters from directly behind the fan, and the blades “slap” the air forward to the target. The EXAIR Super Air Amplifiers does not have any blades or motors to push the air.  They use a Coanda profile with a patented shim to create a low pressure to draw in the air.   (You can read more about it here: Intelligent Compressed Air: Utilization of the Coanda Effect.)  I will expand a bit more in this blog about how each one performs in moving ambient air.

The reason to move air can vary by application from cooling, drying, cleaning, and conveying.  The more air that can be moved, the better the performance for each of these functions.  With the Super Air Amplifiers and fans, these products can move the air, but what affects air flow?  Velocity, turbulence, and static or back pressure.  As we look at each one, we can start to see the effectiveness within each application.

Super Air Amplifier – flow region

Velocity is air flow per unit area.  This is the speed at which the air is traveling.  Some fan designs can affect the velocity, like the motor and spindle in the center of the axial fan.  Some of the area is removed from the middle of the flow region.  So, the velocity is very weak in the center.  (Reference diagram below).  With the centrifugal fan, the air velocity has to be redirected and pushed out the exhaust.  The velocity profile is very disoriented and will work against itself within the flow region.  If we look at the EXAIR Super Air Amplifier, the center is open as shown above.  There are no obstructions.  Since we are drawing in the ambient air, the velocity profile is laminar meaning that the flow is even across the entire flow region.  Laminar flow is optimum for a uniform force and effective blowing.

Axial Fan velocity profile

Turbulence is the “action” of the air flow.  If the turbulence is high, the air flow pattern is interrupted and chaotic.  It causes the velocity of the air to decrease quickly.  By the time the air reaches the target, it has low energy and force.  As a result of turbulence, noise levels can become very loud.  With a centrifugal fan or blower, the air is forced to move at a right angle and pushed out through an exhaust port.  This creates a very turbulent air flow.  The axial fan has less turbulence than its counterpart, but the blades still “slap” the air to push it forward.  This disruption in the flow pattern for both fans create turbulence and disarray.  The EXAIR Super Air Amplifier draws the air into the device to generate very little turbulence on the exhaust end.  The flow pattern is consistent, working together in the same direction.  This will allow for more air to reach the target.

Static pressure is important as it relates to the amount of resistance or blockage.  When blowing air through or around products, this resistance will determine the effectiveness and distance for efficient blowing.  To find the maximum resistance, this would be considered at the dead-end pressure.  When the exhaust is totally blocked, the maximum pressure is created.  In an application, the higher the resistance, the less air that can flow through and around to be utilized.  With fans, it is dependent on the blade types, motor size, and RPM.  Since the EXAIR Super Air Amplifiers do not have motors or blades, it is determined by the inlet air pressure.  So, the higher amount of static pressure, the more resistance that the blowing device can handle.

In comparison, I created a table below to show a model 120024 4” Super Air Amplifier against two different types of fans.  The first thing that you notice is the small package area of the model 120024 as compared to the fans that create similar air flows.  The centrifugal fan requires an addition electrical motor which increases the cost and generates a larger footprint.  The reason for the smaller flow area is the laminar air flow that the Super Air Amplifiers generate.  As stated above, the velocity pattern works together in the same direction.  So, a smaller profile can produce a lot more air movement.  In addition, this helps to create a larger static pressure.  Also referenced above, it will move the air much further to do more work.  With high turbulence, the air movement works against itself causing inefficiencies and louder noise levels.

Specification Table

In physics, it is much easier to pull than it is to push.  The same goes for moving air.  Fans are designed to “push” the air and the Super Air Amplifiers are designed to “pull” the air.  This method of pulling makes it simple to create a laminar flow in a small package which is more efficient, effective, and quiet.  Being powered by compressed air, there is no need for electric motors or blades to “push” the air ineffectively.  With the patented shims inside the Super Air Amplifiers, they maximize the amplification by “pulling” in large amounts of ambient air while using less compressed air.  If you want to move away from blower systems or axial fan systems to get better cooling, drying, cleaning, and conveying; you can contact an Application Engineer for more details.

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

Wet Receivers and Condensate Drains

Receiver Tank

For properly designed compressed air systems, air compressors will use primary storage tanks, or receivers.  They are necessary to accommodate for fluctuations in airflow demand and to help prevent rapid cycling of the air compressor.  (Reference: Advanced Management of Compressed Air – Storage and Capacitance)  There are two types of primary receivers, a wet receiver tank and a dry receiver tank.  The wet receiver is located between the air compressor and the compressed air dryer where humid air and water will be stored.  The dry receiver is located after the compressed air dryer.  In this blog, I will be reviewing the wet receivers and their requirements as a storage tank.

Air compressors discharge hot humid air created by the internal compression.  A byproduct of this compression is water.  By placing a wet receiver on the discharge side of the air compressor, this will create a low velocity area to allow the excess water to fall out.  It will also give the hot air time to cool, allowing the compressed air dryers to be more effective.  With wet receivers, it will reduce cycle rates of your air compressors for less wear and store compressed air to accommodate for flow fluctuations in your pneumatic system.

But, there are some disadvantages with a wet receiver.  For compressed air dryers, it is possible to exceed the specified flow ratings.   If the demand side draws a large volume of air from the supply side, the efficiency of the compressed air dryers will be sacrificed, allowing moisture to go downstream.  Another issue with the wet receiver is the amount of water that the air compressor is pumping into it. As an example, a 60 HP air compressor can produce as much as 17 gallons of water per day.  As you can see, it would not take long to fill a wet receiver.  So, a condensate drain is required to get rid of the excess water.

Condensate drains come in different types and styles.  They are connected to a port at the bottom of the wet receiver where the water will collect.  I will cover the most common condensate drains and explain the pros and cons of each one.

  • Manual Drain – A ball valve or twist drain are the least efficient and the least expensive of all the condensate drains. The idea of having personnel draining the receiver tanks periodically is not the most reliable.  In some cases, people will “crack” the valve open to continuously drain the tank.  This is very inefficient and costly as compressed air is being wasted.
  • Timer Drain Valves – These valves have an electric timer on a solenoid to open and close a two-way valve or a ball valve. The issue comes in trying to set the correct time for the open and close intervals.  During seasonal changes, the amount of water going into the wet receiver will change.  If the timer is not set frequent enough, water can build up inside the receiver.  If too frequent, then compressed air is wasted.  Compared to the manual valve, they are more reliable and efficient; but there is still potential for compressed air waste.

    Timer Relay
  • No-waste Drains – Just like the name, these drains are the most efficient. They are designed with a float inside to open and close a drain vent.  What is unique about the float mechanism is that the drain vent is always under water.  So, when the no-waste drain is operating, no compressed air is being lost or wasted; only water is being drained.  The most common problem comes with rust, sludge, and debris that can plug the drain vent.

All wet receivers require a condensate drain to remove liquid water.  But, the importance for removing water without wasting compressed air is significant for saving money and compressed air.  EXAIR also has a line of Intelligent Compressed Air® products that can reduce your compressed air waste and save you money.  You can contact an Application Engineer for more details.

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

 

Photo: Timer Relay by connectors distribution box.  Attribution – CC BY-SA 2.0

Estimating the Total Cost of Compressed Air

It is important to know the cost of compressed air at your facility.  Most people think that compressed air is free, but it is most certainly not.  Because of the expense, compressed air is considered to be a fourth utility in manufacturing plants.  In this blog, I will show you how to calculate the cost to make compressed air.  Then you can use this information to determine the need for Intelligent Compressed Air® products.

There are two types of air compressors, positive displacement and dynamic.  The core construction for both is an electric motor that spins a shaft.  Positive displacement types use the energy from the motor and the shaft to change the volume in an area, like a piston in a reciprocating compressor or like rotors in a rotary compressor.  The dynamic types use the energy from the motor and the shaft to create a velocity energy with an impeller.  (You can read more about air compressors HERE).  For electric motors, the power is described either in kilowatts (KW) or horsepower (hp).  As a unit of conversion, there are 0.746 KW in 1 hp.  The electric companies charge at a rate of kilowatt-hour (KWh).  So, we can determine the energy cost to spin the electric motors.  If your air compressor has a unit of horsepower, or hp, you can use Equation 1:

Equation 1:

hp * 0.746 * hours * rate / (motor efficiency)

where:

hp – horsepower of motor

0.746 – conversion to KW

hours – running time

rate – cost for electricity, KWh

motor efficiency – average for an electric motor is 95%.

If the air compressor motor is rated in kilowatts, or KW, then the above equation can become a little simpler, as seen in Equation 2:

Equation 2:

KW * hours * rate / (motor efficiency)

where:

KW – Kilowatts of motor

hours – running time

rate – cost for electricity, KWh

motor efficiency – average for an electric motor is 95%.

As an example, a manufacturing plant operates 250 day a year with 8-hour shifts.  The cycle time for the air compressor is roughly 50% on and off.  To calculate the hours of running time, we have 250 days at 8 hours/day with a 50% duty cycle, or 250 * 8 * 0.50 = 1,000 hours of running per year.  The air compressor that they have is a 100 hp rotary screw.  The electrical rate for this facility is at $0.08/KWh. With these factors, the annual cost can be calculated by Equation 1:

100hp * 0.746 KW/hp * 1,000hr * $0.08/KWh / 0.95 = $6,282 per year.

In both equations, you can substitute your information to see what you actually pay to make compressed air each year at your facility.

The type of air compressor can help in the amount of compressed air that can be produced by the electric motor.  Generally, the production rate can be expressed in different ways, but I like to use cubic feet per minute per horsepower, or CFM/hp.

The positive displacement types have different values depending on how efficient the design.  For a single-acting piston type air compressor, the amount of air is between 3.1 to 3.3 CFM/hp.  So, if you have a 10 hp single-acting piston, you can produce between 31 to 33 CFM of compressed air.  For a 10 hp double-acting piston type, it can produce roughly 4.7 to 5.0 CFM/hp.  As you can see, the double-acting air compressor can produce more compressed air at the same horsepower.

The rotary screws are roughly 3.4 to 4.1 CFM/hp.  While the dynamic type of air compressor is roughly 3.7 – 4.7 CFM/hr.  If you know the type of air compressor that you have, you can calculate the amount of compressed air that you can produce per horsepower.  As an average, EXAIR uses 4 CFM/hp of air compressor when speaking with customers who would like to know the general output of their compressor.

With this information, we can estimate the total cost to make compressed air as shown in Equation 3:

Equation 3:

C = 1000 * Rate * 0.746 / (PR * 60)

where:

C – Cost of compressed air ($ per 1000 cubic feet)

1000 – Scalar

Rate – cost of electricity (KWh)

0.746 – conversion hp to KW

PR – Production Rate (CFM/hp)

60 – conversion from minutes to hour

So, if we look at the average of 4 CFM/hp and an average electrical rate of $0.08/KWh, we can use Equation 3 to determine the average cost to make 1000 cubic feet of air.

C = 1000 * $0.08/KWh * 0.746 / (4 CFM/hp * 60) = $0.25/1000ft3.

Once you have established a cost for compressed air, then you can determine which areas to start saving money.  One of the worst culprits for inefficient air use is open pipe blow-offs.  This would include cheap air guns, drilled holes in pipes, and tubes.  These are very inefficient for compressed air and can cost you a lot of money.  I will share a comparison to a 1/8” NPT pipe to an EXAIR Mini Super Air Nozzle.  (Reference below).  As you can see, by just adding the EXAIR nozzle to the end of the pipe, the company was able to save $1,872 per year.  That is some real savings.

Compressed Air Savings

Making compressed air is expensive, so why would you not use it as efficiently as you can. With the equations above, you can calculate how much you are paying.  You can use this information to make informed decisions and to find the “low hanging fruit” for cost savings.  As in the example above, targeting the blow-off systems in a facility is a fast and easy way to save money.  If you need any help to try and find a way to be more efficient with your compressed air system, please contact an Application Engineer at EXAIR.  We will be happy to assist you.

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

 

An Ultrasonic Leak Detector Helps with a Pressure Decay Leak Detector

Ultrasonic Leak Detector

A manufacturing company had a pressure decay leak system to check for leaks in compressed air housings.  Their detector was able to find leaks as small as 0.02 cc/min.  The leak program was designed for recording each housing with a batch/lot number and the corresponding leak data.  If the housing reached or surpassed the leak limit, the part would be marked and quarantined.  The pressure decay leak detector was a sensitive instrument, but it could not tell the operator where the leak was occurring.

How the pressure decay leak detector worked was by pressurizing the housing to a target pressure.  The flow valves would shut, isolating the housing.  After the pressure stabilized, the sensitive pressure sensors would pick up any loss in pressure over time.  If the leak limit wasn’t reached, a green light would indicate a good leak test.  If the limit was reached, a red light would indicate a failed leak test, and the housing would have to be segregated.

Reference Filter Housing

The housing design used a head, a bowl, a drain, and a differential pressure gauge.  The leak paths were numerous.  It could be at the drain, between the drain and the bowl, between the head and bowl, at the differential pressure gauge, and even in the casting of the head.  The heads were made from a die-casted aluminum.  If the process was not done properly, porosity could occur in the head.  The leak detector was sensitive enough to find any voids that would allow air to pass through the head casting.  With these many areas of potential leaks, it could be problematic if the reject rate was high.

For the application above, it is important to find where the leaks are occurring in order to create a corrective action.  In order to find the leaks, they purchased a model 9061 Ultrasonic Leak Detector from EXAIR.  Instead of pressure decay, the Ultrasonic Leak Detector uses sound.  Whenever a leak occurs, it will generate an ultrasonic noise.  These noises have a range of frequencies from audible to inaudible.  The frequencies in the range of 20 Khz to 100 Khz are above human hearing, and the Ultrasonic Leak Detector can pick up these high frequencies, making the inaudible leaks, audible.  The model 9061 has three sensitivity ranges and a LED display; so, you can find very small leaks.  This unit comes with two attachments.  The parabola attachment can locate leaks up to 20 feet (6.1 meters) away.  And the tube attachment can define the exact location.  With this application, they used the tube attachment to locate the leaks.  After retesting the failed housings, they found that 80% of the rejects were from a sealing surface.  They were able to replace or repair the o-rings.  10% of the leaks were coming from the drain.  3% of the rejects were leaking at the differential pressure gage.  Both the drains and the pressure gages could be replaced with new units.  7% of the housings had a porosity problem in the head of the housing.  For these, they were shipped back for evaluation to create a modification for a better casting.  The production manager shared with me that an extra vent hole was required to reduce the void.  This was a huge savings for the die-caster and manufacturing plant.

EXAIR Ultrasonic Leak Detector is a great tool.  It can be used in a variety of applications including compressed air systems, bearing wear, circuit breakers, refrigerant leaks, and gas burners to name few.  For the company above, it was a great tool to improve their assembly and testing process for their housings.  If you have an application where you need to find an ultrasonic noise, you can speak with an Application Engineer to see if the model 9061 Ultrasonic Leak Detector could help.

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

An Overview of the How EXAIR Cabinet Coolers Work

 

My colleague, Brian Bergmann wrote a blog on how the EXAIR Cabinet Coolers work, “Cabinet Coolers 101”.  I want to extend that conversation about how EXAIR Cabinet Coolers can better benefit you and your equipment.

With the hot summer months upon us, elevated temperatures can cause shutdowns and interference with electrical systems.  For every 10 deg. C rise above the operational temperature, the life of an electrical component is cut in half.  With freon based coolers, higher ambient conditions make them less effective; and opening the electrical panel to have a fan blow inside creates a dangerous electrical hazard as well as blowing hot, humid, dirty air inside the cabinet.  To reduce loss in production and premature equipment failures, it is important to keep the electrical mechanisms cool.  The EXAIR Cabinet Coolers are designed to do just that.

How does the Cabinet Cooler work? 

EXAIR Cabinet Coolers are powered by a Vortex Tube which only uses compressed air to generate cold air.  They do not have any moving parts, freon to leak, or refrigerant compressors to fail.  These simple, but effective, cooling devices can be used in the toughest of environments.  With the Vortex Tube as the “engine, the reliability of the EXAIR Cabinet Cooler is unmatched and makes it an easy choice for cooling electrical panels.

How the EXAIR Cabinet Cooler System Works

What NEMA ratings does EXAIR offer? 

To match the same integrity as your electrical panel, EXAIR offers three different types of NEMA ratings that are UL listed and CE compliant.  NEMA 12 is dust and oil tight, and can be related to the IEC standard, IP54.  NEMA 4 is dust and oil tight as well as splash resistant for indoor and outdoor use.  The NEMA 4X is the same as the NEMA 4 except it is made of stainless steel for corrosive areas and aggressive wash-down environments.  Both the NEMA 4 and 4x corresponds to an IP66 rating.  EXAIR Cabinet Coolers are easily installed and can match your electrical panel to keep the electrical components safe inside.

What size Cabinet Cooler do I need? 

EXAIR makes it easy to get the proper cooling with the Cabinet Cooler Sizing Guide.  This sheet goes over the important information to determine the external and internal heat loads.  It also indicates the proper NEMA type and electrical requirements for easy installation. The cooling power ranges from 275 BTU/hr to 5,600 BTU/hr, and with the filled-out form, we can make sure that the correct model is used.

What types of systems are offered? 

EXAIR offers a continuous operating system and a thermostat-controlled system.  The continuous operating system includes the selected Cabinet Cooler, a filter, and a cold air distribution kit.  The system will continuously cool until it is manually or automatically turned off.

The thermostat-controlled system is the most efficient way to operate a Cabinet Cooler.  This system comes with the selected Cabinet Cooler, filter, cold air distribution kit, a thermostat and an electrical solenoid valve.  The system is designed to operate only when cooling is needed.  The thermostat controls a solenoid valve, and it is preset at 95°F (35°C).  The thermostat can be easily adjusted to match other desired temperatures.  The solenoid valves come in three different voltages, 120Vac, 240Vac, and 24Vdc (which ever voltage is easily accessible).  With the thermostat-controlled system, you do not have worry about the system operating during off-peak conditions or cooler seasons.

What other options does EXAIR offer with the Cabinet Cooler Systems? 

For better temperature control, EXAIR can replace the standard thermostat and solenoid valve with the ETC, or Electronic Temperature Control.  It is a digital temperature controller with a LED screen for precision monitoring and adjusting.  The controller has easy-to-use buttons to raise or lower the desired internal cabinet temperature.  Once set, the ETC will hold the temperature to +/- 1 deg. F (+/- 0.5 deg. C).  The LED displays the internal temperature for continuous monitoring.  The ETC comes complete with the controller and a solenoid valve in two different voltages, 120Vac and 240Vac.  The ETC is a great option for real-time accurate measurements for your panel cooling.

EXAIR NEMA 4X 316SS Cabinet Cooler System with Electronic Temperature Control installed on control panel in a pharmaceutical plant.

Another option that EXAIR offers is the Side Mount Kit.  They are used to mount the Cabinet Coolers on the side of the electrical panel.  They are manufactured to match the NEMA rating of the Cabinet Cooler.  If you have limited space, don’t worry.  The Side Mount Kits gives you more areas to mount the Cabinet Cooler to your electrical panel.

What about harsh environments? 

With elevated ambient temperatures like near ovens, the high temperature version would be your option.  The HT Cabinet Coolers work in temperatures from 125 deg. F to 200 deg. F (52 deg. C to 93 deg. C respectively).  With refrigerant coolers, the elevated temperatures make it very difficult to cool effectively.  But with the EXAIR HT Cabinet Coolers, the high temperature will not affect the ability to blow cool air.

If the environment is extremely dirty with lint, fibers, debris, etc., EXAIR offers a NHP, or Non-Hazardous Purge, version. The solenoid valve is designed to allow 1 SCFM of compressed air into the panel to keep a slight positive pressure.  With the NHP Cabinet Coolers, the ingress of any fine particles into your electrical panel are eliminated.

For food and beverage, pharmaceutical, and corrosive type of applications, EXAIR can offer NEMA 4X Cabinet Coolers made from 316SS material.  With the high corrosion resistance, the 316SS Cabinet Coolers will continue to operate without degrading in tough environments.

Electrical shutdowns are expensive and annoying.  If you have interruptions from high internal temperatures, EXAIR Cabinet Coolers are a great solution.  They can be installed quickly and easily.  With no moving parts or costly preventative maintenance needed, they can operate for decades in keeping your electronics cool.  If you have any questions about Cabinet Coolers or the Sizing Guide, you can contact an Application Engineer at EXAIR.  We will be happy to help.

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

Super Air Knife with a Plumbing Kit Removes Gypsum from a Conveyor Belt

Plumbing Kits

A gypsum facility was having issues in losing powder from the tailings in their conveying system.  The conveyor moved gypsum from their processing plant to an outside silo bin location for loading and transportation.  The conveyor that they used was 60” wide.  As the conveyor went around the end to dump the gypsum powder, some of the material would stick to the belt and collect on the floor underneath.  Depending on production rates, they would have to stop the operation to clean up the floor which added additional hours for custodial work.  The customer sent a picture of the problem and wondered if EXAIR could help them with this application.

The facility did an annual cost projection to determine the loss of money from the gypsum material collecting under the conveyor.  The custodial cost to clean up the excess powder was roughly $45,000/year.  The unscheduled downtime was estimated at 115 hours per year.  (They did not share the loss of dollars in production to EXAIR.)  But it was large enough that they needed a solution from EXAIR.  (The photo below is similar to the same application as written by Lee Evans: “EXAIR Super Air Knives Improve Process in an Aluminum Rodding Shop“.)

Powder collecting under conveyor

I suggested a model 110260PKI Super Air Knife Kit for this application.  The Super Air Knife was 60” in length to cover the conveyor belt.  The kit included a filter, a regulator, and a shim set to “dial” in the minimum amount of force to remove the material.  This gives the customer the most flexibility when using an EXAIR Super Air Knife.  The “PKI” suffix at the end of the model number indicates our Plumbing Kit.  This kit which is Installed on the Super Air Knife allows for ease of installation to compressed air connections and it also allows for the proper airflow to get a consistent blow-off across the entire length of the Super Air Knife.

At EXAIR, we pride ourselves in energy efficiency.  Compressed air is expensive to make, so why not use it as efficiently as you can?  The Super Air Knife has a 40:1 amplification ratio which allows 40 parts of ambient “free” air for every 1 part of compressed air.  And, with the “dirty” environment at the gypsum facility, the Super Air Knife would not be affected as they do not require a motor that can fail or a maintenance program to perform.  After installing the model 110260PKI, the gypsum powder was no longer collecting on the floor underneath.  If we look at the cost of removing the hourly rate of the custodian, the Return on Investment, ROI, was only 27 days (and this did not include the increase in production rates).

Spillage is wasteful, costly, and time consuming to cleanup.  If you have excess waste from your conveying system, EXAIR will have the product to help you.  For the gypsum facility above, the Super Air Knife Kit made it possible to increase production efficiencies with a short ROI.  You can contact an Application Engineer to review your application and see if we can improve your conveying operation.

John Ball

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