Intelligent Compressed Air: Refrigerant Dryers and How They Work

We’ve seen in recent blogs that Compressed Air Dryers are an important part of a compressed air system, to remove water and moisture to prevent condensation further downstream in the system.  Moisture laden compressed air can cause issues such as increased wear of moving parts due to lubrication removal, formation of rust in piping and equipment, quality defects in painting processes, and frozen pipes in colder climates.  The three main types of dryers are – Refrigerant, Desiccant, and Membrane. For this blog, we will review the basics of the Refrigerant type of dryer.

All atmospheric air that a compressed air system takes in contains water vapor, which is naturally present in the air.  At 75°F and 75% relative humidity, 20 gallons of water will enter a typical 25 hp compressor in a 24 hour period of operation.  When the the air is compressed, the water becomes concentrated and because the air is heated due to the compression, the water remains in vapor form.  Warmer air is able to hold more water vapor, and generally an increase in temperature of 20°F results in a doubling of amount of moisture the air can hold. The problem is that further downstream in the system, the air cools, and the vapor begins to condense into water droplets. To avoid this issue, a dryer is used.

Refrigerated Dryer

Fundamental Schematic of Refrigerant-Type Dryer

Refrigerant Type dryers cool the air to remove the condensed moisture and then the air is reheated and discharged.  When the air leaves the compressor aftercooler and moisture separator (which removes the initial condensed moisture) the air is typically saturated, meaning it cannot hold anymore water vapor.  Any further cooling of the air will cause the moisture to condense and drop out.  The Refrigerant drying process is to cool the air to 35-40°F and then remove the condensed moisture.  The air is then reheated via an air to air heat exchanger (which utilizes the heat of the incoming compressed air) and then discharged.  The dewpoint of the air is 35-40°F which is sufficient for most general industrial plant air applications.  As long as the compressed air stays above the 35-40°F temperature, no further condensation will occur.

The typical advantages of Refrigerated Dryers are-

  1.  – Low initial capital cost
  2.  – Relatively low operating cost
  3.  – Low maintenance costs

If you have questions about getting the most from your compressed air system, or would like to talk about any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Drying Small Diameter Wires

An overseas company contacted me about an issue with drying copper wires.  Their production process utilized fourteen wire drawing machines in their facility.  They could make very fine wire in the range of diameters from 0.2mm to 2.6mm.  Some of their drawing machines were able to make a maximum of sixteen wires at the same time.

Each wire is made by a process of drawing and annealing.  The machine will draw a thicker copper wire through dies that will get progressively smaller in diameter.  Before the material goes through the dies, the copper is annealed to make it ductile and workable.  Annealing is a process of heating to make the material softer.

In this application, once the wire was to the correct diameter, it would go through a coolant bath to cool and harden.  To remove the coolant from the wires, it would travel over a set of drying cloths.  From there, the wire would travel out of the drawing machine and into a spooler.

The spooler places the wire onto a spool for packaging and shipping.  The reason that they contacted EXAIR was because the wires were not properly dried before it went to the spooler.  If any coolant was left on the surface, it would corrode the wires in that area.  They needed a better way to dry the wires because they started to receive complaints from their customers.

Site for Super Air Knife on exit of Wire Drawing Machine

When the company first contacted me, they had an interest in the Super Air Wipes.  The Air Wipes are designed to blow air in a 360 deg. pattern around the wire to dry the entire surface.  But, after getting more details about their process, the sixteen wires were coming out of the drawing machine at 1.75cm apart.

With the gap between the wires being so small, the Super Air Wipes would not be able to fit around each wire.  As another engineered solution, I recommended the Super Air Knives Kit, model 110212.  The Super Air Knives are 12” long (30.5cm) to span across all sixteen wires.  The kit includes a filter, regulator, and shim kit to accommodate different forces for different wire speeds.

The Super Air Knife can blow a laminar flow of air consistently across the entire width.  Air, as a fluid, likes to “hug” the surface.  Since the air stream isn’t turbulent, the contact time along the surface of the wire will be much longer; making it very effective at removing liquid.

I had the customer mount one Super Air Knife above and one Super Air Knife underneath, spanning across the entire row of wires.  They were positioned at a 45 deg. angle to blow in the opposite direction the wires were traveling.

Being compact, the Air Knives could be placed at a close distance near the drawing machine to blow the excess coolant back into the machine.  This would keep the floor clean and safe from coolant collecting on the ground.  So, no matter the diameter of wires being drawn through the machine, the Super Air Knives would be a non-contact way of drying the surface without having to use the drying cloths which were inconsistent and had to be replaced often.

Super Air Knife Drying Wires

If you require a non-contact way of keeping your product clean and dry, EXAIR has many products to tackle this.  No matter how large or small of a profile, we can efficiently and effectively accomplish this. You won’t have to replace items that wear or cause damage to your product by improper contact.  EXAIR has the ability to use compressed air to create a strong force without scraping or scratching your material.

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

Super Air Amplifiers – Adjustability for Blowoff, Drying, Cooling, Circulation and Ventilation

The Super Air Amplifier is a powerful, efficient, and quiet air mover. Applications currently in place include blowoff, drying, cooling, circulation and ventilation. Sizes from 3/4″ to 8″ are available to best match the air volume that is necessary to achieve the process goals. There are a couple of ways to change the performance of the Super Air Amplifier if either a small or large change to the output flow is required.AirAmplifiers

The chart below shows the Total Output Flow for each of the 6 models. As an example, the Model 120021 or 121021, when operated at 60 PSIG of compressed air supply, will have a total output flow of 120 SCFM. These same devices when operated at 80 PSIG will have a total flow of 146 SCFM. By simply using a pressure regulation device on the compressed air supply, the output performance can be tuned to match the desired outcome.

Capture

For those applications where much greater flow and/or force is needed, the option of installing a thicker shim is available.  The Super Air Amplifiers are supplied with a 0.003″ shim installed (the 8″ model 120028, has a 0.009″ shim as standard) and can be fitted with shims of thicknesses of 0.006″ or 0.009″ (the 8″ model has an optional 0.015″ shim.) Installation of a thicker shim increases the slotted air gap, allowing for a greater amount of controlled air flow.  As a general rule, doubling the shim thickness will double the air flow rates.

Super Air Amplifier Shims

Patented* Shim Design for Super Air Amplifiers

The Super Air Amplifier design provides for a constant, high velocity outlet flow across the entire cross sectional area,.  The balanced outlet flow minimizes wind shear to produce sound levels that are typically three times quieter than other air movers. By regulating the compressed air supply pressure and use of the optional shims, adjustability and flexibility of the unit is wide ranging and sure to meet your process needs.

If you have questions regarding the Super Air Amplifier, or would like to talk about any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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*Patent #5402938

Super Air Amplifiers vs. Fans – Why are Amplifiers More Effective at Cooling & Drying?

Super Air Amplifier

Super Air Amplifiers entrain ambient air at a rate of 25:1!!

When seeking a suitable solution for cooling or drying your parts, you may be tempted to try out a low-cost fan to get the job done. While fans do a great job of keeping you cool during the warmer months, they’re not the best choice for cooling or drying parts. Have you ever noticed that when standing in front of a fan the flow pattern is not consistent? This is due to the nature in which the fan blades create that air flow by “slapping” the air as they spin rapidly. The air flow that exits from the fan is turbulent and is not as effective as the laminar air flow pattern that is produced by EXAIR’s Super Air Amplifier. The Super Air Amplifier utilizes a patented shim design that maintains a critical position of the air gap and creates a laminar air flow pattern that will exit the outlet of the unit.

fan data2

In addition to providing laminar air flow more conducive for cooling and drying, the Super Air Amplifier provides much more air that can be directed at the target. A standard 2.36” x 2.36” DC operated fan provides anywhere from 12-27 CFM at the outlet, depending on the model. For comparison, a Model 120022 2” Super Air Amplifier will provide 341 SCFM at the outlet when operated at 80 psig. At just 6” away from the outlet, this value increases to 1,023 SCFM!! When compared to the fan outlet air flow, the Super Air Amplifier produces more than an 1,100% increase in air volume!

When replacing a fan with a Super Air Amplifier, the process time can be dramatically reduced. The increase in air volume significantly reduces the contact time that your part will need to be exposed to the air flow, allowing you to increase your line speed and decrease the overall production cost of the part. This is achieved due to the nature in which a Super Air Amplifier draws in air from the ambient environment. At amplification ratios as great as 25:1, the Super Air Amplifier is the best way to move a lot of air volume across the part with very little compressed air supplied to it. Check out the video below for a good representation of the air entrainment of a Super Air Amplifier.

In addition to providing laminar airflow and increasing the volume of air, the Super Air Amplifier is also infinitely adjustable through one of two ways. Each size Super Air Amplifier has a shim set that can be purchased. Swapping out the stock shim for a thinner shim will reduce the compressed air consumption, force, and flow. Installing a thicker shim will increase it. Additionally, the force and flow can also be adjusted by regulating the input supply pressure through the use of a pressure regulator. With sizes ranges from ¾” up to 8”, there’s a Super Air Amplifier for all applications. Give us a call today to see how you can optimize your process by replacing your fans with one or more Super Air Amplifiers.

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@Exair.com
Twitter: @EXAIR_TD

Air Amplifiers – Vent, Exhaust, Cool, Dry, Clean – With No Moving Parts!

As an Application Engineer, one of the interesting aspects of working with customers on applications is the varied types of solutions an EXAIR product can provide.  The Air Amplifier family – Super Air Amplifier, Adjustable Air Amplifier, and the special High Temperature Air Amplifier can be used in a wide variety of process and applications.  Below highlights several of those from past experiences.

A defense contractor was performing maintenance service on a Navy ship, and the ventilation system had to be shut down.  To keep the personnel cool and safe, an auxiliary ventilation was to be supplied.  Rather than use a cumbersome blower assembly, which has to mounted on the top deck, and ducted down to the lower decks, they chose to utilize (2) 4″ Super Air Amplifiers.  They are very portable and can be set up in minutes.  This solution provided the necessary air flow, providing a safe environment for the maintenance crew.

Super Air Amplifier

EXAIR Air Amplifiers use a small amount of compressed air to create a tremendous amount of air flow.

A light bulb manufacturer needed a better solution for a cooling operation.  During manufacturing of a mercury lamp, the bulb must be cooled from 700°C to 600°C in just 15 seconds.  The current method, an open brass pipe, was working but the noise level was too high (95 dBA.) The goal was to maintain the 15 second cooling time, but reduce sound levels to 85 dBA.  By utilizing (2) of 3/4″ Adjustable Air Amplifiers, the customer was able to maintain the cooling rate, and reduce the noise level down to 80 dBA, a 15 dBA reduction.

adjustable Air Amplifier

Adjustable Air Amplifier

A garbage collector presented a problem that needed a solution.  The garbage was incinerated and when the furnaces were first started up, there tended to be issues with getting the flue to draft properly.  Using the High Temperature Air Amplifier, the high velocity air flow and draw provided the needed draft until the stack warmed up and the natural draft would be established.  Since the unit is capable of handling temperatures up to 700°F, it was able to withstand the heat of the process after the compressed air was turned off.

These and other Applications for the Air Amplifiers and all other EXAIR products can be found on the EXAIR website on the Products page, under the Related Info section toward the bottom of each page.

If you have questions regarding Air Amplifiers or any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

Send me an email
Find us on the Web 
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Twitter: @EXAIR_BB

Super Air Knives Remove Water from Knee Replacement Parts

EXAIR’s Super Air Knives are the go to when you need to dry your parts as they’re traveling along a conveyor. The high velocity, laminar airflow from the Super Air Knife does a fantastic job of stripping away moisture, leaving your part dry for the next stage of the process. With models available in both 303 & 316 Stainless Steel, Aluminum, and polyvinylidene fluoride and at lengths ranging from 3″-108″, there’s a knife for every application.

I was recently working with a customer that manufactures knee replacement devices. He was designing a new blowoff station to eliminate having to have operators manually dry the parts after a washing operation. He created a test rig to test out his theory of using Super Air Knives. While conducting his tests, he was having issues completely removing the water from the parts. Due to some of the grooves and pockets, the underside was not drying in one pass. This led to him having to manually blow the parts off after they exited the basket. This would not be acceptable as the purpose was to remove the operator from this part of the process. After taking a look at some photos of the setup, I noticed that he had the knives angled so that the airflow was blowing perpendicular to the parts. In doing this, the amount of time that the part is exposed to the airflow is greatly reduced. In any blowoff application, maximizing the time & contact that the part has with the airflow is critical in maximizing effectiveness. By angling the knives so that the parts were exposed to the airstream just as they exited washing, he was effectively able to dry the parts in one pass.

Optimized-IMG_20170313_133531

Improper Positioning of Super Air Knives

We’re frequently contacted by customers who may have the right product for the application, but are not seeing the results they expected. EXAIR has a highly trained team of Application Engineers that are ready and waiting to help you optimize your installation. In addition, EXAIR offers an unconditional 30 Day Guarantee on all stock products. We want you to have an opportunity to test the product out in your application before committing to the purchase. In doing this, we have the unique opportunity to work with you as you troubleshoot the application. If you have an EXAIR product installed and still aren’t seeing the results you expect, give us a call. We’d be happy to look into your setup and determine if there’s anything that can be done to enhance the performance.

Tyler Daniel
Application Engineer

E-mail: tylerdaniel@exair.com
Twitter: @EXAIR_TD

83% Cyle Time Improvement with EXAIR Super Air Amplifiers

EXAIR Super Air Amplifier – an easy way to quickly move large air volumes

 

At a shipyard in Finland, our distributor found an application using blowers which needed a more viable solution.  The application was to dry the interior of large tanks after coating, and the original solution was to use a blower mounted to a 12” opening on top of the tank.  The airflow from the blower was forced into the tank in an effort to dry the coating but often ended up without any drying effect at all.

This problem was due to vapors (non-combustible vapors) produced by the coating process which are more dense than the ambient air, causing them to collect on the bottom of the tank.  The airflow produced by the blower was not sufficient to force these vapors from the tank, causing a long drying cycle for the coating process or no drying at all.

But, these same tanks feature a 3” diameter plug in the bottom of the tank to allow for draining if needed.  And, this opening is almost perfectly sized for a 2” EXAIR Super Air Amplifier model 120022.  (Model 120022 has an outer diameter of 2.95” at the side which provides incoming ambient air.)  By removing the plug in the bottom of the tank and installing a 2” Super Air Amplifier, this tank can be fully dried in a fraction of the time required for an electric blower setup.  The end user estimated an 83% reduction in drying times (from one hour per tank to ~10 minutes), and gained confidence that the tanks would be 100% dry and free of vapor when using the EXAIR solution.

One additional benefit of this Super Air Amplifier solution was increased reliability.  The electrical supply to this shipyard is unstable, resulting in blackouts and surges which shut down electric blowers.  But because the Air Amplifiers do not rely on electricity and sufficient storage capacity was available for compressed air, these units are unaffected by electrical supply problems.

If you have a similar application or would like to discuss a problem currently present in your production facilities, contact an EXAIR Application Engineer.  We’re here to help.

Lee Evans
Application Engineer

LeeEvans@EXAIR.com
@EXAIR_LE

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