Taming The Dust Cloud With EXAIR Atomizing Spray Nozzles

Have you ever dropped one of your nice dinner plates on a tiled kitchen floor? And noticed how they seem to go in slow motion as they hurtle to their doom? I never cease to be impressed at how far some of the smaller pieces can go. I recently had to replace our oven, and I found broken dishware shards (and an impressive amount of trash scraps, pet toys, and ‘dust bunnies’) all the way against the back wall.

Curiously, as small as the pieces can be when a dinner plate meets its end, it started its life in even smaller pieces…as a fine ceramic powder, pressed into a mold and heated to a temperature that is WAY hotter than when the server at your favorite restaurant warns you that plate “might be hot.”

I’m writing about this because recently, I had the pleasure of assisting a maker of ceramic dishware with a messy little problem…this fine ceramic powder is moved from where it’s produced, to the various mold stations (dinner plates, salad plates, saucers, etc.) on a vibratory belt conveyor. The vibration keeps the powder loose and homogenous, both of which are extremely important to the molding & firing process. It also causes a cloud of dust to rise along the entire length of travel, and they wanted to minimize this. Their chemists had told the engineer who called me that they could live with a small amount of moisture, as long as it wasn’t enough to make the powder clump up – this would evaporate out at a point closer to the molds anyway.

This was an ideal application for the EXAIR Atomizing Spray Nozzles…they produce a fine mist of liquid that is precisely controllable…one Model AW1010SS Internal Mix, Wide Angle Round Pattern Nozzle was installed near the beginning of the line, and once they find out how long it takes the dust-suppression supplied by the misted water to evaporate away, they will install more nozzles accordingly.

EXAIR Atomizing Spray Nozzles are a perfect solution for dust suppression.

EXAIR Atomizing Spray Nozzles are a perfect solution for dust suppression.

EXAIR Atomizing Spray Nozzles are ideal for situations where you need a fine liquid mist and fine adjustment of the flow & pattern. With ninety models to choose from, we’ve got the one you’re looking for. Call me if you want to find out more.

Russ Bowman
Application Engineer
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Proper Air Supply Is Key To Optimal Performance

I recently worked with a customer who was using our 36″ aluminum Super Air Knife to remove dust and light debris from a conveyor but wasn’t seeing good performance. They initially called because they read in their catalog that increasing the shim gap would increase their force and flow and wanted to know what kind of increase in performance they would see.

The Super Air Knives are shipped from EXAIR with a .002″ shim installed and the performance data shown in the catalog reflects this gap setting. The shim sets, for aluminum knives, include a .001″, .003″ and .004″ shim and by changing to the .003″ shim, the force and flow would be 1.5 times as great and using the .004″ shim would double these amounts. While some applications do require the additional force and flow, trying to blow off dust or light materials typically wouldn’t fall into this category.

sak-shims

Replaceable shims provide varying levels of force and flow.

Switching our focus to the supply side of things, it turns out they were using 1/4″ hose and only plumbing one end of the unit. This poses 2 concerns that relate directly to the mentioned poor performance. The first would be the 1/4″ hose is severely undersized for a 36″ Super Air Knife. We recommend 3/4″ Schedule 40 pipe if the length of supply from a main header is 10′ or less and a 1″ pipe up to 50′ of supply run. It is possible to use hose but that hose needs to be at least 1″ ID to be able to carry enough volume to support a 36″ unit. Secondly, for knives that are 24″ in length or longer, you need to plumb air to both ends to maintain an even, laminar flow across the length of the knife.

With the proper supply, the Super Air Knife is going to produce an exhaust air velocity of 11,800 feet per minute when operated at 80 PSIG, which is more than enough to eject lightweight material from a flat surface (in fact you could most likely clean dust and light debris at a lower pressure). If the customer did increase the shim gap dimension, the increase in  air demand would only worsen the problem of undersized supply lines.

Pipe sizes

Recommended supply line sizes per the IOM – Installation and Operation Manual.

This is just one example of how proper supply line size and installation is key to achieving optimal performance. If you are experiencing similar issues or need any assistance with a product or application, give me a call, I am glad to help.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

 

Will an EXAIR Vacuum Work with This Material?

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Activated carbon pellets in need of vacuuming

At the heart of EXAIR’s dry vacuum systems are a modified design to our Line Vac air operated conveyors.  These units convert a compressed air supply into a powerful vacuum source with no moving parts and thus no components to wear out.  This, in turn, translates to an instantaneous vacuum supply that is both durable and maintenance free.

These aspects of our vacuum systems led a pharmaceutical research company in Macau to contact us about using a Heavy Duty Dry Vac in one of their applications.  The complete details of the application were proprietary, but information about the specific use was made available.

What this customer needed to do, was to vacuum activated carbon chips in batches of ~300kg (660 pounds) into a contained drum or bag.  The ultimate question in the application was whether an EXAIR Heavy Duty Dry Vac system can vacuum 300kg of activated carbon.  And, if it can, how long will it take?  To answer these questions we turned to a bit of data about the activated carbon, and the potential vacuuming rate of the Heavy Duty Dry Vac System.

Activated carbon has a bulk density of ~0.52 g/cm³ (~32.5 pounds/ft³), and the Heavy Duty Dry Vac can vacuum this type of material at a rate of ~30kg/min. or more (~66 pounds/min. or more).  This means that we’ll be able to vacuum the full 300kg of activated carbon in ~10 minutes!

But, where will it all go?

If we were to use a 55 gallon Heavy Duty Dry Vac, we could vacuum ~105 kg. (232 pounds) of this material before filling the drum.  But, if we use a 110 gallon system, we will double this capacity while keeping the performance and compressed air demand of the system exactly the same.

The multiple sizes of EXAIR vacuum systems provided a wide array of solution options in this application.  After discussing these options and receiving a request for distributor contact in China, we passed this customer over to our Chinese distributor.

Providing solutions for industrial applications is the forte of EXAIR Application Engineers.  It doesn’t matter if the application is here in the States, or overseas, we’re available for any questions our customers have.

If you’d like to discuss your application with an EXAIR Application Engineer we’re available by phone, email, or online chat.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Siphon Fed Atomizing Nozzle Improves Roll Forming Process

Last week I worked with a gutter manufacturer who was looking for a way to spray a light coating of vanishing oil on the rollers of a forming machine. Roll forming is commonly used when needing to maintain a constant and consistent shape or feature across the length of the part. In this particular case, a sheet of aluminum, used as a cover for the gutter, is fed into the machine where it passes over a series of dyes that bends “ribs” and punches small holes into the part to keep leaves or debris from settling on top, while allowing the rainwater to pass through the holes and into the gutter.

They were needing to apply the oil to the rollers because they were starting to see some irregularities in hole size as well as some deformities to the shape of the ribs due to heat being generated during the forming process. The customer was interested in using some type of atomizing spray nozzle in the hopes that providing an atomized mist of liquid may provide for a faster evaporation of the oil so there wasn’t much residue left on the part before packaging.

After further discussing the details, they advised that they were going to have the oil in a container about 12″ below the machine but didn’t have a way to pressurize or pump the liquid to the nozzle. Once again, EXAIR has the perfect solution with our 1/4 NPT Siphon Fed Atomizing Nozzles. These nozzles are the ideal solution where pressurized liquid isn’t available as they use the compressed air to the draw the liquid into the nozzle, up to 36″ of suction height, and mix it internally to produce a mist of atomized liquid spray. For this particular application, the Model # SR1010SS was a good solution as it provides a low flow rate of only 0.8 GPH and a tight spray pattern to focus right at the rollers to avoid any waste or overspray.

sr1010ss

Model # SR1010SS Siphon Fed Round Pattern Atomizing Spray Nozzle – 303ss construction, fully adjustable flow rate

EXAIR offers an extensive range of Atomizing Nozzles that can be used for light coating applications, like above, or for wider coverage areas or higher flow rates. For help selecting the best option to fit your needs, contact one of our application engineers for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

How Do You Make Cement? Start with Clinkers

Last week I wrote about the use of the Atomizing Nozzles to create a fog for wet room curing of concrete samples poured during road construction.  This week, I had the opportunity to work with another customer about concrete, but this time it was regarding the the manufacturing process.  Invariably, I always learn something new , and for this interaction, it was the term ‘clinkers.’

Concrete is a composite material composed of coarse aggregate bonded together with a fluid cement that hardens over time.  The customer I was working with was a cement manufacturer.  Cement production is basically a 2 step process – 1) clinker is produced from raw materials and 2) cement is produced from cement clinker.

clinkers

Typical Cement Clinkers

To make the clinker (step one), several powder raw materials are fed into a rotary kiln.  The kiln is heated to very high temperatures, and when the materials are mixed and heated, new compounds are formed and hydraulic hardening occurs resulting in the formation of the clinker.

My customer needed a way to clean off the residual dust left on the transport belts, after the clinkers were transported to storage silos.  Due to the high temperatures in the area, we focused in on the EXAIR Type 303 Stainless Steel model of the Super Air Knife, as it can withstand temperatures up to 800°F.  The customer went with (3) of the Super Air Knife Kits, which include the Shim Set, Auto Drain Filter Separator, and Pressure Regulator w/ Gauge, for easiest installation with maximum functionality.

The Super Air Knife is a tried and true product for cleaning, drying, cooling and general blowoff for conveyors.  And with widths up to 108″ available, any size conveyor can be handled.

To make cement (step two), the clinker is ground into fine powder with other ingredients including gypsum (calcium sulphates) and possibly additional cementitious (such as blastfurnace slag, coal fly ash, natural pozzolanas, etc.) or inert materials (limestone). It is then stored or packaged and ready to be made into concrete.

To discuss your application and how an EXAIR Super Air Knife can benefit your process, 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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Can Counting Carbs Help in Your Compressed Air System?

Breakfast Cereal

Breakfast Cereal

Have you ever counted the amount of carbs that you eat?  People typically do this to lose weight, to become healthier, or for medical reasons like diabetes.  Personally, I like to eat cereal in the morning.  I will pull a box of cereal down from the cupboard and look at the Total Carbs field.  One morning, I looked at a box of gluten-free rice flakes and compared it to a peanut butter nugget cereal.  I noticed that the carbs were very similar.  The rice cereal had 23 grams of total carbs while the peanut butter nuggets had only 22 grams of total carbs.  Then I looked at the serving size.  The rice cereal had a serving size of 1 cup while the nuggets only had a serving size of ¾ cups.  So, in comparison, for one cup of nugget cereal, the total amount of carbs was 27.5 grams.  Initially, I thought that they were similar, but the peanut butter nugget was actually 20% higher in carbs.  This same “misdirection” occurs in your compressed air system.

Here is what I mean. Some manufacturers like to use a lower pressure to rate their products.  This lower pressure makes it seem like their products will use less compressed air in your system.  But, like with the serving sizes, it can be deceiving.  It is not a lie that they are telling, but it is a bit of misconception.  To do an actual comparisons, we have to compare the flow rates at the same pressure (like comparing the carbohydrates at the same serving size).  For example, MfgA likes to rate their nozzles at a pressure of 72.5 PSIG.  EXAIR rates their nozzles at 80 PSIG as this is the most common pressure for point-of-use equipment.  You can see where I am going with this.

To compare nozzles of the same size, MfgA nozzle has a flow rate of 34 SCFM at 72.5 PSIG, and EXAIR model 1104 Super Air Nozzle has a rating of 35 SCFM at 80 psig. From an initial observation, it looks like MfgA has a lower flow rating.  To do the correct comparison, we have to adjust the flow rate to the same pressure.  This is done by multiplying the flow of MfgA nozzle by the ratio of absolute pressures.  (Absolute pressure is gage pressure plus 14.7 PSI).  The ratio of absolute pressures is:  (80PSIG + 14.7) / (72.5PSIG + 14.7) = 1.09.  Therefore; the flow rate at 80 PSIG for MfgA nozzle is now 34 SCFM * 1.09 = 37 SCFM.  Now we can compare the flow rates for each compressed air nozzle.  Like adjusting the serving size to 1 cup of cereal, the MfgA will use 9% more compressed air in your system than the EXAIR model 1104 Super Air Nozzle.  This may not seem like much, but over time it will add up.  And, there is no need to waste additional compressed air.

Family of Nozzles

Family of Nozzles

The EXAIR Super Air Nozzles are designed to entrain more ambient air than compressed air needed. This will save you on your pneumatic system, which in turn will save you money.  The other design features gives the EXAIR Super Air Nozzle more force, less noise, and still meet the OSHA compliance.

If you want to run a healthier compressed air system, it is important to evaluate the amount of compressed air that you are using. To do this correctly, you always want to compare the information at the same pressure.  By using the EXAIR Super Air Nozzles in your compressed air system, you will only have to worry about your own weight, not your pneumatic system.

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

 

Picture: Breakfast Cereal by Mike Mozart Creative Commons Attribution 2.0 Generic License

Finding The Right Solution Through Dedicated Engineering Support

crate

Plastic crate in need of blow off after washing

An OEM of crate washing equipment in Lebanon recently contacted me about an application on one of their conveyors.  The conveyor carries a plastic crate out of a washer and excess water on the crate was presenting a problem in the application.  In order for the crate to move on to the next step in the machine, a blow off solution was needed, but the exit rate from the washer was inconsistent.  In a given minute there could be 5 crates exit the washer, or there could be 20.  So, the ideal solution needed to have intermittent control options with instantaneous on/off functionality.

We immediately began discussing Super Air Knives, not only because we show plastic crate blow off in one of our many videos, but also because these units are instant on/off with full compatibility with a flow control device.  Utilizing a flow controller, such as the EXAIR Electronic Flow Controller or PLC device, will allow for precise control of the blow off solution, limiting compressed air use to a minimum.

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The first blow off system design

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This layout utilizes Air Knives on each side of the blow off as well as the top

After discussing application details we came to the design shown above, using one 24” Air Knife on the top of the crate and two 9” Air Knives on the sides.  However, this OEM had purchased numerous 2” Flat Stainless Steel Super Air Nozzles in the past (model 1122SS) and had a number available on site.  Modifying the system to utilize the nozzles already on-site, we came to this design:

system-layout

The finalized layout for this blow off system. Click for a larger view.

This layout utilizes (1) 24” Stainless Steel Super Air Knife on the top of the crate and (2) sets of (3) 2” Flat Stainless Steel Super Air Nozzles on the sides, held in place with EXAIR Stay Set HosesNotice the independent pressure regulators for the nozzles and the knife.  This is to allow the customer to balance the air flows, because the 2” flat nozzles will create a higher force than the Air Knife when operating at the same pressure.

In this application we were able to help a returning OEM solve their problem with the right mix of needed products.  Exploring the problem and discussing numerous viable solutions led to the best fit for the application and customer.  That’s precisely why EXAIR Application Engineers are available for any application call or question.  If you’d like to explore an EXAIR solution we’ll be happy to help.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

 

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