Another Unique Solution in an Aluminum Processing Plant

Fine dust particles needed to be removed from this belt on the underside of a conveyor

A few months back I wrote about the impact of installing Super Air Knives in an aluminum processing plant.  Those Super Air Knives solved a recurring problem with cleaning alumina dust around conveyors and reduced costs for the end user by over $80k.

That same customer has also found a method to remove fine dust from the underside of the conveyor belt in an application area not suitable for an Air Knife.  In this application there was no dust collection system in place to carry away the fines as they are blown off of the belt, so a different type of solution was needed.

Model 150200 Heavy Duty Line Vac provides the vacuum needed to remove the dust fines.

That solution was to install a Heavy Duty Line Vac affixed to a vacuum hood to remove fines from the belt and convey them back to the head chute.  The only problem with this setup was that the 2” Heavy Duty Line Vac produced a bit too much vacuum flow than what was really needed in the application.  So, a pressure regulator was installed to allow for adjustment and fine tuning of the vacuum solution.  The customer was able to adjust the operating conditions for the Line Vac and minimize compressed air use while maximizing the vacuuming effect on the fines stuck to the conveyor.

The Line Vac used in this application quickly and easily solved a chronic problem plaguing this manufacturer.  By installing this vacuum solution they were able to prevent build-up of dust and debris underneath the conveyor which originally required shutting down the line to clean.  This improved process uptime, reduced cleaning costs, and increased throughput in the application.

If you have an application in need of a vacuum solution, consider an EXAIR Line Vac.  And, if you have any questions, contact an EXAIR Application Engineer.  We’ll be happy to help.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Music And The Mini Cooler

Recently, EXAIR Corporation offered CPR (cardiopulmonary resuscitation) training to employees. I already carry certification, so I held down the fort while some of the other Application Engineers received this training. As a middle aged man, I have to admit that my interest in my co-workers’ abilities to respond to a matter of this nature is not entirely unselfish.

One of the key parts of CPR training is the rate of the chest compressions. While most people couldn’t accurately replicate 100 beats per minute on demand, almost everyone is familiar enough with some popular songs with a rhythm close to that.  The song they always bring up in CPR training is “Stayin’ Alive” by the Bee Gees. Depending on how you feel about disco, another option is “Another One Bites The Dust” by Queen. Pro tip: it might be considered bad form to sing that one out loud while performing CPR.

Speaking of music, while I was holding down said fort during this morning’s training session, I had the pleasure of assisting a caller in the music business: a piano restoration & tuning professional. A frequent job for them consists of resetting tuning pins, which requires drilling numerous small holes (a grand piano can have as many as 250) into a hardwood board. They’re pressed in, so it’s critical that they fit the newly-drilled hole precisely. If the drill bit gets too hot, it can expand in diameter, making the hole ever-so-slightly bigger than it should be. The heat can also cause the surface of the hole ID to glaze. Both of those things can cause problems with the pin fitting securely in the hole.

The EXAIR Model 3808 Mini Cooler System was an ideal solution – it’ll keep the drill bit cool & clean with a constant stream of cold air. It’s compact and quiet, and only uses 8 SCFM @100psig…well within the capacity of many smaller air compressors.

If you’d like to “get in tune” with a spot cooling solution, I can help…call me. Oh, and in case you wanted to know which song with about 100 beats per minute I’d use for CPR:

Russ Bowman
Application Engineer
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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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