Replacing Unsafe Open Pipes with High Pressure Air Nozzles

Open pipes present unsafe working conditions and continuous pressure drops in compressed air systems

Let’s talk for a minute about pressure drops. Normally when the topic of pressure drops is raised, it comes in a context related to proper plumbing and volume supply.  (If there are significant pressure drops within a compressed air system, especially those which reduce volume flow, problems will arise with compressed air driven devices.)

But, there is another important aspect of pressure drops which relates to open pipe blow-off, a common homemade remedy for blow-off applications. This aspect has to do with the available compressed air pressure at the exhausting point from the pipe or nozzle.  In the case of an open pipe, it requires so much compressed air volume that, there can be a continuous pressure drop from the compressor to the open pipe.  However, when a nozzle is installed onto a compressed air pipe, there is a restriction to the flow and the entire pressure drop takes place across the nozzle.

What this means for the blow-off solution is a higher velocity blow-off and a more powerful force from the airflow, with less compressed air consumption.

To think of it another way, imagine the flow of water from your garden hose. If the hose is open-ended and the water is fully on, the flow will be high and the force will be low.  But, when you install a nozzle onto the end of the hose the flow reduces and the force increases.  This is because the pressure drop in the system is taking place across the nozzle rather than the entire system.

This type of a scenario was taking place in the image shown at the top of this blog. The plastic lines connected to the aluminum manifold were fully open on the end, providing a continuous pressure drop and poor blow-off performance.  This, coupled with the maximum operating pressure of similar types of hose being 35 PSI, led to a poor performance in this application.

The solution for this customer was to replace these open pipe blow-offs with EXAIR model 1126 Flat Super Air Nozzles and 12″ Stay Set Hoses, model 9262. The flat airflow of the 1126 Super Air Nozzles provide a highly efficient and forceful blow-off, and the Stay Set Hoses allow for articulation of the nozzles into any position needed.

By replacing these open pipes this customer saved compressed air, added safety (open pipes present an operating hazard per OSHA Standard CFR 1910.242(b)), and improved the performance of their operation.

If you have a similar application or would like to speak with someone about increasing the efficiency of your compressed air applications, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Getting A Little More Vacuum and Flow

Last week, a customer called and indicated that he was a long time user of the model 6013 High Velocity Air Jet.

6013

Model 6013 High Velocity Air Jet

The customer was using the Air Jet to remove light trim scrap from a manufacturing process. The Air Jets utilize the Coanda effect (wall attachment of a high velocity fluid) to produce air motion in their surroundings.  A small amount of compressed air to the Air Jet is throttled through an internal ring nozzle at speeds above sonic velocity.  In the above image, this produces a vacuum at the left side, pulling in large volumes of surrounding air. By utilizing this vacuum pull and ducting the right side exhaust, air and scrap stream to a collection area. The customer assembled a small, efficient, and inexpensive scrap removal system.

The reason the customer had called in was there were some recent changes to the manufacturing process and needed a bit more vacuum force and flow to handle larger scrap and longer travel. We explored using a larger shim, but they were already using the largest size (0.015″.) We talked about the other products that EXAIR offers (Air Amplifiers, Line Vacs) that are used for scrap removal and conveyance.  But with any change, there are usually other modifications and approvals that must be dealt with in order to proceed. So we hit upon the Adjustable Air Jet, which is an adjustable version of the model 6013.

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Model 6019 Adjustable Air Jet

The model 6019 Adjustable Air Jet utilizes an adjustable air gap in place of the fixed shim thickness.  This allows for greater air flow, which results in greater vacuum and conveyance distances. As is the case for many customers, we gathered some additional data to help this customer make a decision. We set up each of the units and tested them at maximum capabilities, and the model 6019 was shown to deliver upwards of 50% greater flow.  The customer felt certain this level of performance would handle what the changed process would require, and best of all, no modifications to any part of the set-up would be required, simply install the 6019 where the 6013 was currently placed.

The High Velocity Air Jet is also part of the model 1909 Blowoff Kit, and is also used in the model 8193 Ion Air Gun and model 8194 Ion Air Jet, for Static Elimination applications. Of course, each can be purchased as an individual item.

To discuss your application and how an EXAIR Intelligent Compressed Air Product can make your process better, 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

Send me an email
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Twitter: @EXAIR_BB

 

Video Blog: EXAIR Swivel Fittings

A brief video showcasing the full EXAIR Swivel fittings offering. Each of the 9 Swivel Fitting models offers a 25° from center line adjustment for a total of 50° full range of adjustment. The Swivel fittings are an ideal accessory for a variety of EXAIR products.  For more product details see our product page.  For any questions or fitment suggestions contact an Application Engineer.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

Offshore Pipe Welding Cooled with Series of EXAIR Super Air Nozzles

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EXAIR model 1122 Flat Super Air Nozzles used to provide cooling blow off.

One of the services we provide to our customers, is assistance in selection of the most suitable product solution for their application.  For most applications we have solutions readily available from stock, though that wasn’t the case in the solution shown above.

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This unique blow off solution cools welds on 450mm (18″) pipes.

This configuration of model 1122 Flat Super Air Nozzles is used to cool pipe welds in an application located off the coast of France.  Pipes with an OD of 450mm (~18”) are welded together, and in order for the welds to be of the highest quality, they must be cooled.  To cool the welds, this customer needed to blow ambient temperature air over the pipes.

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Closeup of nozzles used in this application

Initially, we explored a Super Air Wipe solution.  A Super Air Wipe can provide a full 360° blow off for this pipe, but there was an aspect of the application which led to a better solution through nozzles; an irregularity in position of the pipe.

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Another view of the 1122 Flat Super Air Nozzles

The diameter of the pipes in this application is relatively constant, but there is some fluctuation in position as the pipe is moved.  If using a Super Air Wipe, this could mean contact with a precision machined surface, resulting in a change to the performance of the unit.  But, what if we could find a way to allow the blow off solution to have some “flex”.

swivels

Flat Super Air Nozzles with swivels provide the unique solution needed for this application.

“Flex” in this solution is provided through the use of EXAIR model 9053 swivel fittings, shown above with red circles, each used to mount an 1122 Flat Super Air Nozzle (16 of each).  These allow for proper placement of the nozzles, and also for movement if anything should ever contact the blow off solution.

An additional benefit of the EXAIR 1122 nozzles used in this application, is the ability to exchange shims inside the nozzle to increase or decrease the amount of force delivered from the nozzle.

Understanding the critical requirements of the customer led to this semi-custom solution using EXAIR Super Air Nozzles.  If you‘d like to explore an EXAIR blow off solution for your application, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Bench Testing with Blowoff Kits

Last week, a customer connected with us online via the chat option.  He explained that he was working on a project to remove dust from parts on a table conveyor, situated in a 3 x 5 array. He had purchased the EXAIR Blowoff Kits model 1909SS and model 1910 and had been able to bench test and develop a blowoff system that was successful.  He was ready to scale the up design and procure a set of nozzles and swivels that would work in the automated process.

1909SS Blowoff Kit

Model 1909SS – Stainless Steel Blowoff Kit

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Model 1910 – Instant Blowoff Station

 

The Blowoff Kits such as the Model 1909SS offer an easy way to explore the various nozzle types that EXAIR offers and to test the performance of each for Force, Flow and Sound Levels in your process or test environment.  Each nozzle will have particular traits, and identifying the one that most perfectly matches all your criteria can be done.

The Model 1909SS Blowoff Kit contains (7) different nozzles, all with stainless steel construction.  Included are (4) sizes of the Super Air Nozzle (10, 14, 35 and 60 SCFM capacities), the Micro Air Nozzle, the Adjustable Air Nozzle, and lastly, the 2″ Flat Super Air Nozzle.  A similar Blowoff Kit, model 1909, is available with materials of construction of zinc aluminum alloy, aluminum, and brass.

We have put together a detailed review of blowoff applications, available in the Third Edition of the Air Nozzles Blowoff Guide.  Inside, you can find the technical specifications of all of the Nozzles, Blowoff Kits, Flexible Stay Set Hoses, and Safety Air Guns, that might be of interest to you and your application.

blowoff guide

To Request a copy of the EXAIR Blowoff Guide click here

To discuss your application and how the EXAIR Nozzle and Jets 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

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

 

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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