Heat of Compression Dryers

A Heat of Compression regenerative desiccant dryer for compressed air

Before compressed air can be realistically utilized, it needs to be delivered to the point of use with proper volume and pressure, and it should also be clean and have some moisture removed.  We have information available regarding cleaning compressed air, but how do you dry the compressed air?  And why do you dry the compressed air?

Drying compressed air is akin to removing the humidity in the air when using an air conditioning system.  If the moisture is not removed, the effectiveness of the system is reduced and the ability to use the output of the system is reduced as well.

But, from a functional standpoint, what does this really mean?  What will take place in the compressed air system if the air is not dried and the moisture is allowed to remain?

The answer is in the simple fact that moisture is damaging.  Rust, increased wear of moving parts, discoloration, process failure due to clogging, frozen control lines in cold weather, false readings from instruments and controls – ALL of these can happen due to moisture in the compressed air.  It stands to reason, then, that if we want long-term operation of our compressed air products, having dry air is a must.

So, how can we remove the moisture in the compressed air?  One of the most common methods to remove moisture is a regenerative dryer, specifically, heat-of-compression type dryers.  A heat of compression type dryer is a regenerative desiccant dryer which uses the heat generated by the compression of the ambient air to regenerate the moisture removing capability of the desiccant used to dry the compressed air.

When using one of these dryers, the air is pulled directly from the outlet of the compressor with no cooling or treatment to the air and is fed through a desiccant bed in “Tank 1” where it regenerates the moisture removing capabilities of the desiccant inside the tank.  The compressed air is then fed through a regeneration cooler, a separator, and finally another desiccant bed, this time in “Tank 2”, where the moisture is removed.  The output of “Tank 2” is supplied to the facilities as clean, dry compressed air.  After enough time, “tank 1” and “tank 2” switch, allowing the hot output of the compressor to regenerate the desiccant in “tank 2” while utilizing the moisture removing capabilities of the desiccant in “tank 1”.

Heat of compression dryers offer a lower power cost when compared to other dryers, but they are only applicable for use with oil free compressor and to compressors with high discharge temperatures.  If output air temperatures from the compressor are too low, a temperature booster/heater is needed.

If you have questions about your compressed air system and how the end use devices are operating, contact an EXAIR Application Engineer.  We’ll be happy to discuss your system and ways to optimize your current setup.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

 

Heated Desiccant Dryer by Compressor1.  Creative Commons License

Super Air Knife Makes EVERYTHING Better

When we compare the EXAIR Super Air Knife to other methods of providing a curtain or sheet of air flow in terms of operating cost, efficiency, safety, and sound levels, the Super Air Knife is ALWAYS the clear choice.

The EXAIR Super Air Knife is the most efficient and quietest compressed air blow off product on the market today.

The Super Air Knives successfully replace these, and many other methods of providing a curtain or sheet of air flow all the time, while saving compressed air and decreasing noise.  The word “replace” oftentimes means “do the same job as.”

What you’re about to read is NOT one of those times.

A paper products manufacturer has a machine that treats a specialty product, and the process generates ozone (O3) at levels that would exceed personnel exposure limits, so they need to be contained.  They installed a long piece of drilled pipe to blow an air barrier, but they could only run the machine at about 65% of their desired capacity before the ozone level in the operators’ area exceeded their limits.

This company was familiar with several of our product lines already…they had several Cabinet Cooler Systems, a Reversible Drum Vac, and Super Air Knives in a variety of applications, so they knew how they worked.  Since the barrier needed to be 120″ long, though, this was going to be a much larger scale than they were used to.

Not only was the drilled pipe loud and inefficient, it was not particularly effective either.

Still, the installation of two Model 110060 60″ Aluminum Super Air Knives, coupled with our Model 110900 Air Knife Coupling Kit, was quick and easy.  Then came the good part: they found they were able to operate the machine at 100% capacity, while keeping the ozone at a safe level in the operators’ area.

EXAIR Super Air Knives provided a total solution: quiet, efficient, and most of all, EFFECTIVE.

Then came the better part:  The machine was pretty loud (we couldn’t do anything about that,) at 93dBA when it was running.  With the drilled pipe in operation, it was 94.5dBA.  When they took that out and installed the Super Air Knives, there was no net increase in noise level…it remained at 93dBA.

THEN came the even better part: Compressed air consumption was reduced to about 30% of what the drilled pipe was using.  Right in line with our table above.  Just another validation of the trustworthiness of our published data.  As EXAIR’s President is fond of saying, “Claims are easy, proof is hard.”

If you’re looking for a quiet, efficient – and effective – solution for a compressed air product application, give me a call.

Russ Bowman
Application Engineer
Find us on the Web
Follow me on Twitter
Like us on Facebook

Removing Static From Diaper Absorbent Material

This is where the absorbent material inside a disposable diaper is made

The image above shows one step in the process of disposable diaper manufacturing.  In this step of the process, the absorbent material is ground through a mill on the top of the “bunker” where it falls down a shaft and onto a mesh screen.  Once on the mesh screen, the material is repressed into the proper size and shape for placing into the diapers.

This manufacturer contacted one of our Russian distributors about the application because the milling of the absorbent material was creating static.  This static caused the material to adhere to the walls of the bunker chute and to unevenly distribute onto the mesh.  This unevenness leads to holes in the pressed/shaped absorbent material which translates to a reject rate of ~1 out of every 20 diapers.

An EXAIR Ion Bar

The ideal solution in this case needed to eliminate the static within the chute to allow for proper distribution on the mesh below and proper material placement into the diapers.  An Ion Bar was originally desired by the customer, but material accumulation on the emitter points was a concern so this solution was removed from consideration.

An EXAIR Ion Air Cannon

An Ion Air Cannon, however, was able to provide the desired solution by mounting outside of the chute and feeding a low volume of ionized air to remove the static.  The ionized airflow from the Ion Air Cannon is strong enough to permeate the full volume of the application, but low enough to not disturb the absorbent material within the process. Using an Ion Air Cannon allowed this manufacturer to eliminate defects and wasted materials, increase their throughput, and improve the quality of their products.  Defects dropped from 1/20 diapers to less than 1/1000.

If you have a similar application or similar needs, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Back Blow Air Nozzles Clean Inside Diameters

They say time flies when you’re having fun. Maybe that’s why I found it a little hard to believe it’s been almost two years since we introduced the Back Blow Air Nozzles. They’ve become yet another “textbook” solution to a great many applications:

*Model 1004SS M4 Back Blow Air Nozzles are used to dry the inside of a closed cylinder after a zinc bonding process.  They’re also fitted to Model 1204SS-12-CS M4 Back Blow Safety Air Gun to remove chips & cutting fluid from freshly cut pipe ends.

*Our Model 1006SS 1/4 NPT Back Blow Air Nozzle won Plant Engineering Magazine’s “Product Of The Year” Bronze Award in 2015, and are successfully employed in a wide range of uses:

  • Blowing out splined bores by a gear manufacturer
  • Quickly cleaning out spindles between tool changes by a CNC machinery operator
  • Removing the last bits of powder from spent toner cartridges by a printing equipment recycler

*The Model 1008SS 1 NPT Back Blow Air Nozzle is becoming famous in hydraulic cylinder repair shops…after a cylinder bore is honed, one quick pass of the powerful blast it produces cleans bores from 2″ to 16″.  We can even put it on the Model 1219SS Super Blast Back Blow Safety Air Gun, with a 1ft, 3ft, or 6ft extension.

EXAIR Back Blow Air Nozzles come in three sizes, for bores from 1/4″ to 16″ in diameter!

If you want to see how they work, check out this video:

I could have sworn Lee Evans just made that video, but apparently, it’s over a year old now.  Time does indeed fly, and I promise we’re having fun!  If you’d like to find out more about how a Back Blow Air Nozzle – or any of our engineered compressed air products (old or new) – can make your operations quieter, more efficient (and hence, probably, more fun,) give me a call.

Russ Bowman
Application Engineer
Find us on the Web
Follow me on Twitter
Like us on Facebook

Keys to an Efficient Compressed Air System

How do I make our compressed air system efficient?

This is a critical question which plagues facilities maintenance, engineering, and operational personnel.  There are concerns over what is most important, how to approach efficiency implementation, and available products/services to assist in implementation.  In order to address these concerns (and others), we must first look at what a compressed air system is designed to do and the common disruptions which lead to inefficiency.

The primary object of a compressed air system is to transport the compressed air from its point of production (the compressors) to its point of use (applications) in sufficient quantity and quality, and at adequate pressure for proper operation of air-driven devices.[1]  In order for a compressed air system to do so, the compressed air must be able to reach its intended destination in proper volume and pressure.  And, in order to do this, pressure drops due to improper plumbing must be eliminated, and compressed air leakage must be eliminated/kept to a minimum.

But, before these can be properly addressed, we must create a pressure profile to determine baseline operating pressures and system needs.  After developing a pressure profile and creating a target system operating pressure, we can move on to the items mentioned above – plumbing and leaks.

Proper plumbing and leakage elimination

The transportation of the compressed air happens primarily via piping, fittings, valves, and hoses – each of which must be properly sized for the compressed air-driven device at the point of use.  If the compressed air piping/plumbing is undersized, increased system (main line) pressures will be needed, which in-turn create an unnecessary increase in energy costs.

In addition to the increased energy costs mentioned above, operating the system at a higher pressure will cause all end use devices to consume more air and leakage rates to increase.  This increase is referred to as artificial demand, and can consume as much as 30% of the compressed air in an inefficient compressed air system.[2]

But, artificial demand isn’t limited to increased consumption due to higher system pressures.  Leaks in the compressed air system place a tremendous strain on maintaining proper pressures and end-use performance.  The more leaks in the system, the higher the main line pressure must be to provide proper pressure and flow to end use devices.  So, if we can reduce leakage in the system, we can reduce the overall system pressure, significantly reducing energy cost.

 

How to implement solutions

Understanding the impact of an efficient compressed air system is only half of the equation.  The other half comes down to implementation of the solutions mentioned above.  In order to maintain the desired system pressure we must have proper plumbing in place, reduce leaks, and perhaps most importantly, take advantage of engineered solutions for point-of-use compressed air demand.

The EXAIR Ultrasonic Leak Detector being used to check for leaks

Once proper plumbing is confirmed and no artificial demands are occurring due to elevated system pressures, leaks in the system should be addressed.  Compressed air leaks are common at connection points and can be found using an ultrasonic noise sensing device such as our Ultrasonic Leak Detector (ULD).  The ULD will reduce the ultrasonic sound to an audible level, allowing you to tag leaks and repair them.  We have a video showing the function and use of the ULD here, and an excellent writeup about the financial impact of finding and fixing leaks here.

The EXAIR catalog – full of engineered solutions for point-of-use compressed air products.

With proper plumbing in place and leaks fixed, we can now turn our attention to the biggest use of compressed air within the system – the intended point of use.  This is the end point in the compressed air system where the air is designed to be used.  This can be for blow off purposes, cleaning, conveying, cooling, or even static elimination.

These points of use are what we at EXAIR have spent the last 34 years engineering and perfecting.  We’ve developed designs which maximize the use of compressed air, reduce consumption to absolute minimums, and add safety for effected personnel.  All of our products meet OSHA dead end pressure requirements and are manufactured to RoHS, CE, UL, and REACH compliance.

If you’re interested in maximizing the efficiency of your compressed air system, contact one of our Application Engineers.  We’ll help walk you through the pressure profile, leak detection, and point-of-use engineered solutions.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

 

[1] Compressed Air Handbook, Compressed Air & Gas Institute, pg. 204

[2] Energy Tips – Compressed Air, U.S. Department of Energy

Super Air Knife Plumbing Kit Allows Installation In Tight Quarters

I recently had the pleasure of helping a long-time user of our Super Air Knives with a challenging application. They already use quite a few of our Model 110012SS 12″ Stainless Steel Super Air Knives to clean & dry their nonwoven material as it’s being rolled for packaging. They like them because they’re quiet and efficient, but also because they’re durable…this particular product off-gasses a mildly corrosive vapor, which used to corrode other equipment in the area. Not only does the Stainless Steel Super Air Knife resist corrosion itself, the air flow keeps these vapors contained. Two birds, one stone.

They have a new product…same kind of material, but much wider…that needed to be blown off, and the identified the Model 110060SS 60″ Stainless Steel Super Air Knife as a “no-brainer” solution. Thing is, it had to be a pretty even air flow across the length, and a 60″ Super Air Knife has to get air to four ports across its length for optimal performance. And, they wanted to install it at a point where it would serve not only as a blow off, but as a vapor barrier, just like the 12″ Super Air Knives they’re already so fond of. The space was a little limited, though, so they opted for the Model 110060SSPKI 60″ Stainless Steel Super Air Knife with Plumbing Kit Installed, which allowed them to simply run an air supply line to both ends.

EXAIR SS Super Air Knives can be ordered with a Plumbing Kit installed, or you can easily install a Plumbing Kit on your existing Super Air Knife.

If you want to find out more about an engineered solution for your compressed air application – cleaning, drying, vapor barrier, or all of the above – give me a call.

Russ Bowman
Application Engineer
Find us on the Web
Follow me on Twitter
Like us on Facebook

316 Stainless Steel Line Vac Conveys Cookies in Creamery

Cookies in need of pneumatic conveyance at creamery

An overseas ice cream manufacturer reached out to me recently with a request for assistance.  They were in search of a better means to transfer “inclusions” from a storage bin into the blending tanks of their creamery.  The “inclusions” in question, shown above, looked familiar.  I’ve found identical cookies stashed in my sons’ favorite places around the house, so I’m somewhat familiar with their transfer from one place to another.  Fortunately, in this application the cookie transfer is deliberate whereas it is always “magic” or “no one knows how it got there” when it happens at home.

Both solid cookies and crumbs (shown above) are conveyed.

Seeing as how this application involves the transfer of foodstuffs, we immediately explored a 316 grade stainless steel solution, and gathered the necessary data for determining the proper pneumatic conveyor (an EXAIR Line Vac).  Our Line Vacs utilize a high velocity airstream which travels along the ID of a conveyance tube to move material.  Because of this, application specifics like material/material size, bulk density, conveyance height and distance, and required conveyance rate play a key role in proper sizing.  Here’s how the specifics looked for this application:

 

Material:  Dry cookies and cookie crumbs, 8mm-50mm in diameter (5/16” – 2” in diameter)

Bulk density:  0.69 g/cm³ (43 lb./ft.³)

Conveyance height:  None

Conveyance distance:  5m (16.5 feet)

Required conveyance rate:  As high as possible, preferably in the range of 500kg/hr. (1100 lb./hr.)

Available compressed air supply:  170m³/hr. @ 5.5 BARG (100 SCFM @ 80 PSIG)

Material constraints:  316SS mandatory

 

With these details well defined, I used our empirical test data to appropriately size a suitable Line Vac.  In this case, we had a viable solution in our Heavy Duty Line Vac with regards to conveyance rate, but this solution is not the proper material.  So, we matched performance of a Heavy Duty Line Vac in our 316SS Line Vac using model HP6064-316.  Model HP6064-316 is not a stock option and not shown on the website, so having a proper dialogue with an Application Engineer was critical to dialing in on the right solution for this application.

Once the solution was confirmed, this customer was all set.  We worked with them on every aspect of the application solution and ended up shipping them (3) specialized Line Vacs in 316 stainless steel.  The Line Vacs are up and running, helping to make delicious ice cream for expecting customers.

If you have a similar application or are interested in exploring a Line Vac solution, now is the time to act.  We have a Line Vac promotion running through the end of October that includes a free 2” Flat Super Air Nozzle with the purchase of any Line Vac.  Application Engineers are available for any questions you may have via phone (1-800-903-9247), email (techelp@exair.com), and online chat.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

%d bloggers like this: