Tag: spray

Compressed Air Dryers : What are they Good For?

Published on by Jordan T ShouseLeave a comment

Absolutely Nothing….. err ALOT! They are really good for a lot! Specifically removing moisture/condensate from compressed air.

In almost every operation, clean, dry compressed air will result in lower operating costs. The purpose of compressed air dryers is to overcome the dew point of your compressed air by removing water from it. Compressed air can contain humidity, and in the right environments it can reach the dew point temperature and condense into a damaging liquid. This liquid can be problematic, as it can contaminate your products or equipment, causing frozen pipes, and possibly leading to corrosion and other issues.

Now that we know how important they are how do you know which one is right for you?

Types of compressed air Dryers

• Refrigerant Dryer – the most commonly used type, the air is cooled in an air-to-refrigerant heat exchanger. (Here is a great blog deep diving on Refrigerant Dryers)
• Regenerative-Desiccant Type – use a porous desiccant that adsorbs (adsorb means the moisture adheres to the desiccant, the desiccant does not change, and the moisture can then be driven off during a regeneration process). (Here is a great blog deep diving on Desiccant Dryers)
• Deliquescent Type – use a hygroscopic desiccant medium that absorbs (as opposed to adsorbs) moisture. The desiccant is dissolved into the liquid that is drawn out. Desiccant is used up and needs to be replaced periodically. (Here is a great blog deep diving on Deliquescent Dryers)
• Membrane Type– use special membranes that allow the water vapor to pass through faster than the dry air, reducing the amount of water vapor in the air stream. (Here is a great blog deep diving on Membrane Dryers)

The selection of an air dryer is done best by the professional who knows or learns the particular end uses, the amount of moisture which each use can tolerate and the amount of moisture which needs to be removed to achieve this level. Air, which may be considered dry for one application, may not be dry enough for another. Dryness is relative. Even the desert has moisture. There is always some moisture present in a compressed air system regardless of the degree of drying.

For compressed air, the best way to specify dryness is to cite a desired pressure dew point. Different types of dryers, therefore, are available with varying degrees of pressure dew point performance. To specify dew point lower than required for an application is not good engineering practice. (Naming a pressure dew point is how to state the degree of dryness wanted.) It may result in more costly equipment and greater operating expense.

If you have questions about compressed air systems and dryers or any of our 15 different Intelligent Compressed Air® Product lines, feel free to contact EXAIR, and I or any of our Application Engineers can help you determine the best solution.

Jordan Shouse
Application Engineer

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Why Dryers Are Needed in Compressed Air Systems

Published on by Brian FarnoLeave a comment

Air compressors are extremely proficient at compressing anything in the air they are intaking. With that air that is taken in, moisture is going to be present. The amount of moisture will all depend on where you are located geographically and the ambient conditions in the area. Here in Ohio, we experience all 4 seasons so the moisture content is higher in the air during the summer months, rather than the winter months. When this air is saturated with water vapor and the conditions are right, the air reaches a point it cannot hold any additional water vapor. This point is known as the dew point of the air and water vapor will begin to condense to form droplets.

When ambient air is compressed, heat is generated and the air increases in temperature. In most industrial compressed air systems, the air is then processed to an aftercooler, and that is where condensation begins to form. To remove the condensation, the air then goes into a separator which traps the liquid water. The air leaving the aftercooler is typically saturated at the temperature of the discharge, and any additional cooling that occurs as the air is transferred will cause more liquid to condense out of the air. To address this moisture, compressed air dryers are used.

It is critical to the quality of the system and components downstream that actions are taken to prevent this condensation in the air. Condensation is generally detrimental to any point of use application and or the piping that conveys the air. Rust and/or corrosion can occur anywhere in the piping, leading to scale and contamination of the compressed air and processes. When trying to dry products off using compressed air or using the air to atomize a liquid such as paint, adding in these contaminants and moisture will cost production losses.

There are several options when it comes to the type of dryer that one may consider installing on their compressed air supply side.

• Refrigerant Dryer – the most commonly used type, the air is cooled in an air-to-refrigerant heat exchanger.
• Regenerative-Desiccant Type – use a porous desiccant that adsorbs (adsorb means the moisture adheres to the desiccant, the desiccant does not change, and the moisture can then be driven off during a regeneration process).
• Deliquescent Type – use a hygroscopic desiccant medium that absorbs (as opposed to adsorbs) moisture. The desiccant is dissolved into the liquid that is drawn out. Desiccant is used up and needs to be replaced periodically.
• Heat of Compression Type – are regenerative desiccant dryers that use the heat generated during compression to accomplish the desiccant regeneration.
• Membrane Type– use special membranes that allow the water vapor to pass through faster than the dry air, reducing the amount of water vapor in the air stream.
The air should not be dried any more than is needed for the most stringent application, to reduce the costs associated with the drying process. A pressure dew point of 35°F to 38°F (1.7°C to 3.3°C) often is adequate for many industrial applications. Lower dew points result in higher operating costs.
If you have questions about compressed air systems and dryers or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR, and I or any of our Application Engineers can help you determine the best solution.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Atomization: What is it?

Published on by Brian FarnoLeave a comment

Atomization is a word that can be seen throughout the industry in rinsing, coating, painting, lubricating, and cooling applications. The act of atomization is simple, we often refer to it when looking at liquids and it means to break up the liquid stream and form fine droplets.  This is essentially a transfer of energy. There are two mainstream methods to atomize liquids for an application, both with their own advantages.

142 distinct models. 8 different patterns. Liquid flow rates from 0.1 to 303 gallons per hour. If you’ve got a spraying application, EXAIR has an Atomizing Nozzle for you!

The first is air atomizing. This action is done by combining a stream of compressed air with either a pressurized fluid or a siphon/gravity fed liquid.  The air stream can be combined with the liquid internally to the nozzle, hence Internal Mix Atomizing Nozzles. It can also combine outside of the nozzle, like the External Mix Atomizing Nozzles. We have blogged before on where to use each of these as the reason to select between Internal Mix or External Mix is its own topic.

Benefits to air atomization are, smaller droplet/particulate size is achievable.  The compressed air atomization gives the ability to break up more viscous fluids to get better coverage or thinner layers of spray.  Air atomization also gives the ability to use smaller amounts of liquid because the air takes up a portion of the total flow exiting any nozzle.

The second type of atomizing nozzles are hydraulic atomization. This uses the energy from the liquid being pressurized to break up the liquid stream.  Sometimes there are physical impacts within the nozzle that cause the atomization, other times it is just the liquid leaving an orifice that causes the atomization. This gives the ability to still spray a liquid into droplets of various shapes, dimensions, and flow rates. The lack of compressed air often results in larger droplet sizes as well as higher liquid flow rates. Because the liquid has to be pressurized to certain levels it also becomes difficult to spray higher viscosity fluids through hydraulically atomized nozzles.

Benefits to hydraulically atomized spray nozzles range from stronger spray force for rinsing, ease of installation from not needing to plumb compressed air, ability to flow slurries, or other liquids that may clog or dry due to the design of air atomized spray nozzles.

If you would like to discuss the correct nozzle for your spray application, feel free to contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Sanitizing Applications Using Atomizing Spray Nozzles

Published on by Kirk Edwards2 Comments

As our journeys through the COVID-19 pandemic began, EXAIR was deemed an essential business due to our relationships with critical businesses who are also helping to fight the pandemic and keep our lives as normal as possible. Within our customer base, we are proud to include medical, food, pharmaceutical, and nearly every industry listed by the Department of Homeland Security as critical industries.

EXAIR has seen an increase in assisting end-user customers who have in house sanitizing needs and OEMs (original equipment manufacturers) who are producing sanitizing systems or “showers” for their processes and products as demanded by our pandemic circumstances.

Our Atomizing Spray Nozzles, designed to atomize fluids in a wide range of different spray patterns, utilize a small amount of compressed air that mixes with the liquid supply to create a fine mist of atomized liquid. This makes them very effective in applications that utilize expensive paints, oils, or other liquids. Rather than wasting the expensive materials, the nozzle can be set to precisely dispense only what is necessary to achieve a successful application. They are made from type 303 stainless steel.

No Drip Atomizing Nozzle

Atomizing spray nozzles have been critical for customer’s decontamination and sanitizing needs. Most recently we learned they are being used to build an N95 mask sanitizing systems, when the customer needed to replenish their rapidly dwindling supply of atomizing spray nozzles. Don’t forget, we have them in STOCK and ready to ship!

Internal Mix Atomizing Spray Nozzles

Another customer utilizes the Model EF1010SS to perform a dry fogging process inside of residential and commercial rooms to eliminate mold, odors, and pathogens. For them this is a common process, but due to the concerns related to COVID-19 they’ve seen a dramatic increase in business related to pathogen removal. Using a two-step dry fogging process, the solution fills the entire volume of the space to remove any contaminants and prevent against microbial growth in the future. The nozzle provides a fine atomized mist that fills the entire space in a short amount of time. After a physical wipe down of all surfaces, a second solution is applied that prevents future microbial growth.

And yet another customer manufactures decontamination booths for personnel. They’re also noticing an increase in inquiries as companies look to decontaminate their employees upon entering the building. Utilizing (3) of EXAIR’s SF2020SS Atomizing Spray Nozzles, they’re able to spray a decontaminating solution to aid removal of pathogens from their clothing before it has an opportunity to spread around the office.

We are here to help. Let us know if we may help you.

Stay safe,
The EXAIR Team