Increased Temps = Time For A Cabinet Cooler

This past Monday, we kicked off the start to the new Spring season, which means warmer temperatures are in the forecast. Here in Cincinnati, we are expecting temps in the low 40’s up to the high 60’s. We’ve written a couple blogs in the past few weeks about the changes in temps and weather and the proverbial “spring cleaning” and the use of our Vacuum Systems for industrial cleanup.

Another area of concern relating to the increased temps is the overheating and contamination of electrical control panels in industrial environments. As the temperatures go up, many companies are looking for a fast solution and will open the doors on the panel and use a fan to blow air across the sensitive controls. While this method does provide some cooling and seems like a quick fix, you are also introducing dirty, potentially humid air into the enclosure which can result in failures and lost production.  Not to mention, this is an OSHA violation which can lead to potential injury to operators  and/or costly fines.

What seems like a simple fix is actually a BAD idea!

EXAIR’s Cabinet Coolers are a reliable, maintenance free way to keep electrical enclosures cool, dry and clean. The Cabinet Coolers are compressed air operated, with cooling capacities ranging from 275 Btu/hr. up to our largest Dual System of 5,600 Btu/hr. The units discharge the cold air into the cabinet at a slight positive pressure which expels the hot, dirty air, leaving only the cool, clean, dry air from the system. Systems are available for continuous operation, maintaining a 45% relative humidity on a completely sealed cabinet, ensuring no condensation develops inside the cabinet. Our Thermostat Controlled Systems are available in 120VAC, 240VAC or 24VDC, providing a more economical operation by only using compressed air when needed to reach the desired temperature set point. Our thermostats are preset at the factory to 95°F but are adjustable to meet your specific temperature requirement.

How the EXAIR Cabinet Cooler System Works

In order to properly recommend a unit, we need to know the internal heat load of the cabinet or watt loss of the controls inside. We realize this information is sometimes not readily available, so to help simplify the process, we have a Sizing Guide available, which provides the pertinent information requited to calculate the current load. Of course, you can always give us a call and an application engineer can help you over the phone as well.

Cabinet Cooler Sizing Guide

 

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

Not a Fan of Fans Because Rising Air Temp Will Kill Your Electronics

Using a fan is a popular method for machine builders to provide cooling for an electrical enclosure.  The electrical panel stays cool for machine acceptance at the factory, and possibly for even the first 6-8 months of operation and then one day, there is a problem, and the machine shuts down due to an over heated component within the panel. This leads to opening up the panel, possibly placing an external fan, and operation of the machine in an unsafe condition, to meet the daily production needs.  What has led to this situation?  Summertime!

To better understand the situation, let’s review the heat formula.  The total heat content of air consists of the sensible and latent heat factors. Latent heat is the heat that is required to change the state of a material, say from liquid to solid.  Water to ice is an easy way to understand this type of heat.  When heat is removed from water at 32°F it turns to ice at 32°F.  There is no temperature change, but heat has been removed. Sensible heat is dry heat, it is a result in change of temperature, but not change in state or moisture.  For fan cooling, the air and moisture only change temperature and not state, we can focus on the sensible heat portion.

In English units:  Q = Cp x ρ x q x ΔT x 60 min/hr

And for air:

Q –  is the sensible heat flow in BTU/hr

Cp – is the specific heat in BTU/lb °F – 0.2388 BTU/lb °F

ρ – is the air density at standard conditions – 0.075 lb/ft3

q – is measured air flow in ft3/min – CFM

ΔT – is the temperature difference in °F – Final Air Temperature – Starting Air Temperature

Plugging in the constant values, gives us:

Q = 1.0746 x CFM x ΔT

It is common to chart the above formula for various ΔT values, plotting Q vs. CFM values on a dual logarithmic scale, as shown below-

BTU-CFMGraph4

As an example, for an internal heat load of 1300 BTU/hr, to ensure that the temperature rise (from ambient) in the cabinet does not exceed 20°F, 60.5 CFM of air flow is required (the red line above).  A fan with this CFM rating is specified and installed in the panel.

This works  when the ambient temperature is a comfortable 75°F, in a climate controlled factory, or the cooler months of the year.  The problem occurs when the ambient temperature increases to 95°, 100°, or even 105°F,  not uncommon in the summer, and in plants that create large amount of heat, like metal production, and near boiler systems and furnaces.  Under these conditions, the fan will still maintain the 20°F difference, but the internal temperature of the cabinet will rise to 115°-125°F, temperatures where electrical components start to fail or shut down.  The solution to this issue?  Lower the Starting Air Temperature.

The EXAIR Cabinet Cooler Systems use our Vortex Tube technology to take compressed air and provide a cold flow of air that enters the enclosure at 5o°F less than the compressed air temperature.  With a compressed air temperature of 70°F, common for industrial compressed air systems, the Cabinet Cooler will deliver cold air at 20°F.  Again using the chart above, flowing just 20 SCFM of this air will absorb the 1300 BTU/hr of heat (the green line), and result in an internal air temperature 80°F no matter the ambient air temperature.  The electronics in this enclosure will run trouble free, for a long time. This ambient air temperature problem is also true of air-to-air heat exchangers, as the ambient air temperature rises the ability to remove heat diminishes.

Another consideration, the fan system is bringing in air from the surroundings, which is hot and dirty, passing it through a filter (which gets clogged, reduces air flow, and needs to be replaced.) The Cabinet Cooler System, includes an automatic drain filter separator, which filters the compressed air to be free of dirt, dust and moisture. The air entering the enclosure is cool, dry and fee of dust and debris.

ETC CC

NEMA 4 Cabinet Cooler System with Optional Electronic Temperature Control

To discuss your application and how the EXAIR Cabinet Cooler System can be a benefit at your facility, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Super Air Wipes Help a Swiss CNC Machine to be More Accurate

Precision Required

As machined parts require tighter tolerances, machine shops are starting to look at Swiss-type CNC machines.  These types of machines are extremely accurate and very fast in producing small parts.  But in order to reach that level of accuracy, the bar stock may have to be pre-treated by a centerless grinder.

Our customer was using Swiss-type CNC machines with guide bushings to produce a very tight-tolerance part.  Because they were using guide bushings, the outside diameter of the bar stock had to be smooth and concentric.  This helps to reduce any vibration when machining.  A centerless grinder was used to accomplish this.  The bar stock that they used was 10 feet long and it was placed into a bar feeder.  They had to grind the bar to an outer diameter of 30mm with a surface finish of 32Ra.  As they were loading the bar stock, they noticed that the surface finish was scuffed and marred.  This was enough to affect the machining process and not meet the tolerance standard.

As they reviewed the possible causes, they found that after the bar was ground, some grinding remnants were sticking to the outside of the bar.  As the rods were leaving the grinder and placed onto a roller-type conveyor, the oily film and metal shavings were sticking to the rollers.  This would scrape and mark the rods as they traveled along the conveyor toward the Swiss-type machining center.  As an attempt to remove this debris, they attached two copper tubes to blow compressed air onto the top and bottom of the bar.   Not only was this loud and inefficient, it was not effective.  They still had a dirty line along the sides of the rod that remained.  They contacted EXAIR to see if we could help them with this dilemma.

In order to get a consistent blow-off force around the entire circumference of the rod, EXAIR Air Wipes were engineered to be an ideal solution for this kind of problem.  I recommended the model 2482 Standard Air Wipe Kit.  The Standard Air Wipe is designed to blow compressed air in a 360 degree flow pattern.  This air pattern is directed at a 30 degree angle toward the center to blow the debris off of the bar stock.  The Coanda effect maximizes the entrainment of ambient air into the compressed air.  This makes the unit very efficient and powerful.  The model 2482 Standard Air Wipe has an I.D. of 2” (51mm) which gives it enough clearance for the 30mm bar stock.  It can be mounted easily near the exit of the centerless grinder to keep the grinding remnants inside the machine.  The kit includes a filter, regulator, and shim set.  The filter will remove contaminants from the compressed air system to keep from introducing any new grime and to keep the inside of the Air Wipe clean and functional.  The shim set and regulator provide the ability to adjust the air to the ideal force level and remove any debris from the surface of the bar.

Standard Air Wipe with Shim Set

As they removed their home-made copper tubes and attached the Standard Air Wipe, they noticed some great improvements.  The dark lines of debris previously along the sides of the bar stock were gone.  The surface was clean around the entire circumference of the bar.  The customer also noticed that the Standard Air Wipe was much quieter than their home-made solution, as it only has a decibel rating of 77 dBA.  As an added benefit, the Standard Air Wipe was using much less compressed air than the copper tubes.  This is due to its design to maximize the amplification ratio.  With more of the “free” ambient air than the compressed air being moved over the target area, it will save money in compressed air usage.  The ROI could be less than four months.

If you have any items that need to have a 360 degree blowing pattern, you can contact an Application Engineer at EXAIR to see if a Standard Air Wipe could work for you.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb
Picture: External-Micrometer-Screw-Gauge by Emilian Robert Vicol.  Creative Commons license

Will It Spray?

Video showing the intended use of EXAIR Atomizing Nozzles, illustrated with a green spray pattern.

 

One of the common questions we receive with regards to our Atomizing Spray Nozzles, is whether they will spray a specific liquid.  Most of the time this is a simple answer, found by referencing the viscosity of the liquid and the viscosity range of the specific atomizing nozzle in question.  But, sometimes the viscosity of a fluid isn’t readily available and the best path forward is testing of the specific fluid or application.

Such was the case with the videos above and below.  This application was to spray a specific mixture comprised of catnip biomass onto materials as they pass along a conveyor.  There was no specific flow rate required, we simply needed to spray a specific width at a specific distance away from the product.

The video above shows the desired spray pattern from the nozzles, something with a wide angle and flatpattern, and the video below shows the most suitable solution we found in testing at EXAIR.

The suitable nozzle in this application was our model AD2010SS, an internal mix nozzle with deflected flat fan spraying pattern and a patented technology to prevent liquid flow after compressed air to the nozzle is turned off.  This nozzle provided the right solution for this application, and shipped from stock on the same day we received the order.

Fast forward a few weeks and this same application found benefit from an Electronic Flow Controller (EFC) model 9057.  The EFC allows for sensor-based control of compressed air flow, and thereby control of liquid flow to the AD2010SS nozzles.  This prevents operation of the nozzles when there is no need to spray the liquid.

The discussion, testing, and implementation of this solution are an excellent example of the engineering support available behind EXAIR products.  We really do help our customers find solutions, and if there is an unknown in an application we’re willing to find the answers together.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

EXAIR Cabinet Cooler System Meets High Demands Of Sea Duty

I joined the Navy, right after high school, to get out of Ohio, see the world, and never come back. “My recruiter said” (if you are considering military service, those can be famous last words, just so you know) that I would be a good candidate for Nuclear Power School, so I took the test. As a math & science nerd scholar, I qualified for admission easily.  About halfway through Nuke School, I volunteered for submarines.  My decision was based in no small part on the sea stories of our instructors, the strong reputation of better food, and my deep appreciation for the movie “Operation Petticoat.”

Upon graduation, I was assigned to a new construction Trident submarine.  I did not see the world…I saw the Electric Boat shipyard in Groton, Connecticut, and Naval Submarine Base King’s Bay, Georgia.  Hilarity occasionally ensued, but never in the context of that movie I so adored.  I moved back to Ohio (on purpose) soon after my enlistment was up.  The food WAS good…I can unreservedly vouch for that.

In the new construction environment of the shipyard, I became quite familiar, and developed a deep respect for, the high level of attention paid to the materials and workmanship that a seagoing vessel demanded…not to mention, one with a nuclear reactor on board.  Reliability and durability are obviously key factors.

I had the pleasure recently of assisting an electrical contractor who was looking for a cooling solution for a new Variable Frequency Drive enclosure installation on a cement barge.  The ship’s engineer (a Navy veteran himself) had told the contractor that his priorities were reliability, durability, and dust exclusion.  He couldn’t have made a better case for an EXAIR Cabinet Cooling System.

Based on the specified heat load of the VFD, the size of the enclosure, and its location, a Model 4380 Thermostat Controlled NEMA 12 Cabinet Cooler System, rated at 5,600 Btu/hr, was specified.  This equipment is internal to the ship; had it been exposed to the elements, a NEMA 4X system would have been presented.

Up to 2,800 Btu/hr cooling capacity with a single Cabinet Cooler System (left) or as much as 5,600 Btu/hr with a Dual system (right.)

EXAIR Cabinet Cooler Systems have no moving parts to wear, no electric motor to burn out, and no heat transfer surfaces (like a refrigerant-based unit’s fins & tubes) to foul.  Once it’s properly installed on a sealed enclosure, the internal components never see anything but cold, clean air.

If you have a need to protect an electrical enclosure in aggressive environment, give me a call.  With a wide range of Cabinet Cooler Systems to meet a variety of needs, we’ve got the one you’re looking for, in stock and ready to ship.

Russ Bowman
Application Engineer
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Slick Application for a Super Air Knife

A few weeks back I worked with a customer on an unusual application for one of our Air Knives. The company runs a camp, located in the North-Central part of the United States, complete with their own ski hill for skiing, snowboarding or tubing. They use a conveyor belt ski lift where the skier or snowboarder will stand on the belt and be transported back to the top of the hill for another run. They were starting to see some safety issues arise when the mat would get wet and freeze, causing the skiers to slip and fall back.

Photo of the ski belt conveyor

In an effort to remedy the situation, the installed a brush to try and help remove some of the snow and ice from the belt and while this helped a little, there was still moisture on the belt that would re-freeze. To aid in the drying process, they tried to use a floor blower aimed at the belt but the turbulent airflow seemed to “push” the water around rather than wipe it clean and dry. Out of ideas, they found EXAIR while doing an internet search and decided to give us call for assistance.

Further reviewing the details of the application, I recommended our 30″ Stainless Steel Super Air Knife for the application. The Super Air Knife provides an high velocity, laminar sheet of air across the length of the knife. The laminar flow from the air knife, would assure an even drying effect across the belt, rather than the turbulent flow from the blower. The stainless steel construction of the knife would hold up to the potentially harsh environmental conditions as well.

Super Air Knife available in aluminum, 303ss, or 316ss construction in lengths from 3″ up to 108″.

After some correspondence back and forth regarding air requirements and installation recommendations, the customer was able to source a rental compressor and ordered the 30″ Super Air Knife to test under our Unconditional 30 Day Guarantee. After a few weeks of testing, they were able to effectively dry the belt to an acceptable level, increasing the overall safety for their guests.

30″ SS Super Air Knife mounted under the belt on the “return” side.

 

Clever installation allowed for easy angle adjustment to ensure the airflow contacted the belt for optimal blowoff/drying.

EXAIR offers the quietest (69 dBA at 80 PSIG) and longest (up to 108″) Air Knives on the market today and we stock them in the most materials (aluminum, 303SS, 316Ss and PVDF) to best suit your application. To see how you might be able to utilize an Air Knife in your unique application, give us a call at 800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

 

 

 

Taking My Job home With Me (I Wish!)

Last week, as Mother Nature was doing her typical dance between warm, almost Spring like days and then quickly reverting back to her Winter ways, the southwestern Ohio area was hit with a powerful storm. Luckily, my neighborhood area was spared the really strong winds and tornadic activity that nearby areas experienced.  We did however receive a decent amount of rainfall.

Every Spring when the ground is still slightly frozen, the first good rain always leads to some water  leakage into my basement.  The water comes in through the gaps between the floor and the walls and even seeps up through some of the floor cracks.  I have my theories as to why it only happens in the spring, but I’ll save that for another day.  As the blog title says, I wish I had taken home a Reversible Drum Vac with me.

EXAIR  manufactures the Reversible Drum Vac (RDV) System, which attaches quickly to to any 30, 55, or 110 gallon closed head drum. The Mini Reversible Drum Vac has the same great performance and comes complete with a 5 gallon drum.  Coupled with the Spill Recovery Kit, using the RDV to vacuum up the rain water would have been a short and simple process.  Using a mop, towels, fans and a dehumidifier took much longer and still did not get everything dry.

hlrdv

30, 55 and 110 Gallon Reversible Drum Vac Systems

 

The compressed air operated Reversible Drum Vac System is a high powered vacuum that can fill a 55 gallon drum in less than 2 minutes, and with a simple turn of the a knob, the same stainless steel pump quickly empties the drum.  With no electric motor to wear out, or impellers to clog, the RDV is designed to work in industrial environments.  An automatic safety shutoff valve prevents the system from over-filling.

EXAIR also manufactures systems made for cleaning up solids, such as machining chips and other debris.

To discuss your application and how the EXAIR Industrial Housekeeping Products can be a benefit at your facility, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

Send me an email
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Twitter: @EXAIR_BB

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