Desiccant Dryers: Heat of Compression Type

Desiccant Dryers

Desiccant dryers come in different forms.  They are designed for water sensitive areas as they can reach a dew point to -40oF (-40oC) and below.  That means that water will not condense in the compressed air lines until the temperature is below the dew point.  The desiccant inside these units will adsorb the water vapor as compressed air passes through a bed.  Once the desiccant bed is full of water vapor, it will have to be regenerated.

A typical system will use two towers that will switch back and forth.  One tower is used to remove the water from the compressed air system, and the other is used to regenerate the desiccant.  In this blog, I will cover how the desiccant can be regenerated with a Heat of Compression (HOC) type of desiccant dryer.

An air compressor is not an efficient device.  For every eight horsepower of energy to make compressed air, only one horsepower is used as work.  And for compressed air drying, the type of desiccant dryer is important.  Regeneration of desiccant beads can be done either with non-heated or heated means. The non-heated, or heatless version will use 15% of your compressed air to purge through the regeneration tank.  The air escapes into the atmosphere with the water vapor and is wasted.

With the heated type desiccant dryers, they come in three different categories.  One type uses a heater to increase the temperature of the compressed air. At the elevated temperature, the purge requirement can be reduced to 7% for the regeneration of desiccant.  But, still compressed air is wasted.  To cut the purge to zero, a blower-type heated desiccant dryer can be used.  Instead of heating the compressed air, the blower will push ambient air through a heater to regenerate the desiccant bed.  But can you get more efficient than that?

Well, what if you can remove the heater and the blower?  The heat of compression type of desiccant dryers can do that.  Remember above when I mentioned that “for every eight horsepower of energy to make compressed air, only one horsepower is used as work”.  The seven horsepower of energy that is lost is given off as heat.  The HOC dryer uses that heat to regenerate the desiccant bed.  So, the overall energy is reduced even further.  There is a restriction when using this type of dryer.  The air compressor will have to be oil-free because oil will coat the desiccant beads and stop the adsorption rate.

When the air is compressed, heat is generated.  This heated air can reach around 200oF (93oC).  With the higher temperature, air can hold more water vapor.  As the heated air passes through the desiccant bed that needs to be regenerated, the water vapor is picked up from the desiccant beads.  The saturated air would then pass through an aftercooler.  The aftercooler reduces the air temperature below 100oF (38oC) which will cause the water to drop out.  From the aftercooler, the air will then pass through the desiccant bed in the drying tower.   When the cycle time is reached, the towers will switch to regenerate the second tower.

Line Vacs can convey many things.

With these types of dryers, the desiccant beads will start to degrade from regeneration.  To help replace them, EXAIR offers a Line Vac.  Instead of climbing a ladder with many bags of desiccant, the Line Vac can do this safely and ergonomically.   EXAIR Line Vacs use a small amount of compressed air to generate a powerful vacuum by a Venturi effect.  The unique design of the generators creates a high velocity of air to create a low pressure on one side and a powerful thrust on the other.  The Line Vac can pick up and move solid material vertically up to 20 feet (6 meters).  You can watch a video on the operation of a Line Vac HERE.  The EXAIR Line Vacs are very quiet, compact, rugged, and powerful.  To replace the desiccant, it can do it quickly and safely.

If you need to convey solid materials in a quick and easy way, an EXAIR Line Vac could be a solution for you.  We have them in a variety of materials and designs to match your application.  Ergonomically, they can save the back-wrenching labor of picking up bags, climbing stairs, and dumping material into towers.  If you want to know if the EXAIR Line Vac could work for you, an Application Engineer at EXAIR can help to recommend the best unit for you.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

 

Photo: Heated Desiccant Dryer by Compressor1Creative Commons Attribution-No Derivs 2.0 Generic

EXAIR Products Receive Plant Engineering Product of the Year Awards: Silver and Bronze

Since 1983 EXAIR Corporation has been the one stop shop for all your Intelligent Compressed Air needs. Throughout this time, we have taken pride in providing quality, engineered products for our customers. With innovation as a major driving force in our success, we are constantly looking to improve on existing product lines while also releasing new products into the market. These new products are often recipients of various awards and our trophy case out front has grown substantially in size over my 10 years here. In fact, I think we’re about due for another soon after our most recent additions.

That cabinet is filling up again!!

In April 2020, just as the pandemic was increasing momentum, Plant Engineering issued their 2019 awards. In 2019 EXAIR received the prestigious Product of the Year award from Plant Engineering. In the compressed air category, EXAIR took both 2nd and 3rd place bringing home a silver and bronze to add to our trophy case.

Coming in 3rd with the Bronze award was EXAIR’s Gen4 Ionizing Bar. The Gen4 Ionizing Bar was redesigned and engineered to perform up to 25% better than previous generations. In addition to improving on decay speeds, it also increased the effective range by 100%!

Life expectancy has been extended by insertion molding the stainless steel ion emitters into a durable engineered polymer. There are no openings or grooves to accumulate dirt that could cause shorting or arcing. A 5 kV rugged, integrated ground steel reinforced power cable protects against abrasion, tears, and damage common in a rugged industrial environment.

Coming in 2nd place with the Silver award was EXAIR’s Soft Grip Atto Back Blow Safety Air Gun. Using the smallest Back Blow Nozzle available, this gun delivers a strong blast of air capable of blowing out debris and liquids from the ID of small pipes or hose, channels, bores, holes, internal threads, and internal part features. The ergonomic design keeps the operator’s hand comfortable so it can be used for hours without fatigue. A 360° array of holes on the nozzle blows backwards clearing out coolant, chips, and light oils from machining processes. A Chip Shield installed on the extension of the gun then protects operators from any flying debris.

Another year, and another couple of awards for EXAIR. You can count on the sun coming up in the morning, and you can count on EXAIR to consistently provide new innovative products. Year in and year out we continue to provide new solutions for common applications. Give us a call, we’ll be happy to help determine how we can help you improve on your current processes.

Tyler Daniel
EXAIR Corporation
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

The Bernoulli Principle

When catapults would hurl stones and projectiles at castles there weren’t thinking of how the stones flew or what could make them fly better, often they went with the “Tim Taylor method” of MORE POWER.  It wasn’t until thousands of years later that mathematicians started to talk about gases and liquids and how they react to different scenarios. Things like how does air react to a stone being launched through it. Johann Bernoulli played a significant role and calculated a lot of this out throughout his life and discovered what is now called the Bernoulli Principle.

Bernoulli discovered that when there is an increase in the speed of a fluid, a simultaneous decrease in fluid pressure occurs at the same time. This is what explains how a plane’s wing shape matters. It also can showcase how a curveball coming into the strike zone can fall out and cause an outlandish “STTTeeerriike Three” from the umpire. It is also sometimes confused with the Coandă effect. While both effects have a tremendous impact on our modern lives, the best way I have learned these effects is through videos such as the one below.

As mentioned within the video, there are numerous effects that can closely relate to the Bernoulli effect, the best example I see is the curveball which when implemented correctly can cause a very upset batter, while the pitcher has the game of his or her career.

If you would like to talk about some scientific discoveries that have you puzzled, or if you want to figure out how we can use one of these effects to help your application, contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Video Source: Fizzics Organization – 10/8/2014 – retrieved from https://www.youtube.com/watch?v=-c_oCKm5FLU&list=PLLKB_7Zd6leNJmORn6HHcF78o2ucquf0U

When To Ask An Expert

With the Springtime comes many outdoor activities in our house. Sometimes they are new, such as archery which just came about in our house in the last couple of weeks.  The other item that it is time for is our family garden. While we have not started any plants from seed this year, and the opportunity to get to a garden center to purchase plants may not happen, we still want to be prepared.  To do that, we prepared the same plot we have used in years past and laid down some landscaping fabric to try and kill off any unwanted weeds that have already started to sprout up through the dirt.

The next activity was to get the tiller out and perform a tune-up/maintenance on it. Sure enough, first, pull and the cord on the trusty engine lets go. The cord didn’t merely break, it looked like something from the Three Stooges as I almost fell backward from my pulling momentum and very nearly punched myself in the face. I proceeded to disassemble the pull-cord cage and found myself in unfamiliar territory.

Pull-Cord Assembly aka Punch-self-in-face-maker

Had this been another part of the engine, the carburetor, electrical kill switch, engine internals, or even the final drive to the tines, I would have been okay. Oddly enough, I have never had to replace one of these recoilers or the rope that comes on them. When you go to YouTube and search for a topic like this you will find a rather large amount of ways to perform a task like this.

Rather than doing that, I enlisted the help of a close friend who has worked for a lawn care/landscaping company for over a decade. He maintains every piece of equipment the company owns and uses. Needless to say, he has replaced quite a few pull ropes in his time.  When I called, due to social distancing we couldn’t meet in person, he, of course, asked several questions about the tiller and in the end helped me to make sure I had the correct replacement rope.

We then set off to walk through the process and the entire thing took less than 15 minutes.  When it was said and done the pull-start felt better than it had ever since I owned the piece of equipment and after sitting since last year still started on the second pull. Thank God for ethanol-free fuel that is still available at certain locations.

All repaired and ready to till!

The point of this story is, what is received and viewed as a simple task for one can be a monumental task for someone else. While my mechanical aptitude was sufficient, I lacked the training and understanding as to why you would perform this process in a given order. My friend, the expert, did not lack that at this point in time. This process was something that was second nature to him.

This is very similar to point-of-use compressed air applications and the EXAIR team. Our team has experience from a multitude of industries and we all focus on utilizing compressed air efficiently and effectively. If we don’t know the process (which is rare) we are willing to learn and ask questions until we understand enough about your application that we can make an educated recommendation for an optimal EXAIR product. We are all here to help each other and to help our customers achieve their goals, so contact us when you need an expert.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF