Super Air Wipes Help a Swiss CNC Machine to be More Accurate

Precision Required

As machined parts require tighter tolerances, machine shops are starting to look at Swiss-type CNC machines.  These types of machines are extremely accurate and very fast in producing small parts.  But in order to reach that level of accuracy, the bar stock may have to be pre-treated by a centerless grinder.

Our customer was using Swiss-type CNC machines with guide bushings to produce a very tight-tolerance part.  Because they were using guide bushings, the outside diameter of the bar stock had to be smooth and concentric.  This helps to reduce any vibration when machining.  A centerless grinder was used to accomplish this.  The bar stock that they used was 10 feet long and it was placed into a bar feeder.  They had to grind the bar to an outer diameter of 30mm with a surface finish of 32Ra.  As they were loading the bar stock, they noticed that the surface finish was scuffed and marred.  This was enough to affect the machining process and not meet the tolerance standard.

As they reviewed the possible causes, they found that after the bar was ground, some grinding remnants were sticking to the outside of the bar.  As the rods were leaving the grinder and placed onto a roller-type conveyor, the oily film and metal shavings were sticking to the rollers.  This would scrape and mark the rods as they traveled along the conveyor toward the Swiss-type machining center.  As an attempt to remove this debris, they attached two copper tubes to blow compressed air onto the top and bottom of the bar.   Not only was this loud and inefficient, it was not effective.  They still had a dirty line along the sides of the rod that remained.  They contacted EXAIR to see if we could help them with this dilemma.

In order to get a consistent blow-off force around the entire circumference of the rod, EXAIR Air Wipes were engineered to be an ideal solution for this kind of problem.  I recommended the model 2482 Standard Air Wipe Kit.  The Standard Air Wipe is designed to blow compressed air in a 360 degree flow pattern.  This air pattern is directed at a 30 degree angle toward the center to blow the debris off of the bar stock.  The Coanda effect maximizes the entrainment of ambient air into the compressed air.  This makes the unit very efficient and powerful.  The model 2482 Standard Air Wipe has an I.D. of 2” (51mm) which gives it enough clearance for the 30mm bar stock.  It can be mounted easily near the exit of the centerless grinder to keep the grinding remnants inside the machine.  The kit includes a filter, regulator, and shim set.  The filter will remove contaminants from the compressed air system to keep from introducing any new grime and to keep the inside of the Air Wipe clean and functional.  The shim set and regulator provide the ability to adjust the air to the ideal force level and remove any debris from the surface of the bar.

Standard Air Wipe with Shim Set

As they removed their home-made copper tubes and attached the Standard Air Wipe, they noticed some great improvements.  The dark lines of debris previously along the sides of the bar stock were gone.  The surface was clean around the entire circumference of the bar.  The customer also noticed that the Standard Air Wipe was much quieter than their home-made solution, as it only has a decibel rating of 77 dBA.  As an added benefit, the Standard Air Wipe was using much less compressed air than the copper tubes.  This is due to its design to maximize the amplification ratio.  With more of the “free” ambient air than the compressed air being moved over the target area, it will save money in compressed air usage.  The ROI could be less than four months.

If you have any items that need to have a 360 degree blowing pattern, you can contact an Application Engineer at EXAIR to see if a Standard Air Wipe could work for you.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb
Picture: External-Micrometer-Screw-Gauge by Emilian Robert Vicol.  Creative Commons license

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

Compressed Air Has Tremendous Power! Use It Safely

Just the other day, not far from here, a demolition crew at a shuttered factory and a local homeowner got this message, loud & clear, when the crew inadvertently cut into a still-pressurized compressed air cylinder.  It launched, like a missile (an apt description, given the fact that real missiles operate on this exact same principle) some 1,500 feet, across the neighborhood, and into the bedroom of a house, three blocks away.  Here’s what the local news reported on it:

Now, before you go turn your air compressor off and vent your system, let’s look at just a couple of other incredible dangers we place ourselves in close proximity to every day:

Driving a car: I came to work this morning in a 3,500lb mass of metal, plastic, and glass, hurtling at speeds of up to 65 miles per hour (that’s my story and I’m sticking to it.)  This would be an insane thing to do, were it not for:

*The engineering, design, and maintenance that makes the vehicle safe to operate,

*The training, experience, and periodic re-licensing required to maintain driving privileges,

*The upkeep of roadways, bridges, traffic signals, etc., and

*The monitoring and enforcement of traffic safety measures by our law enforcement officers.

Operating electrically powered devices:  if you’re reading this on a computer screen, you’re likely surrounded by objects that are connected directly to 120 volts of alternating current electricity.  That stuff will stop your heart.  Thank goodness all that current is contained, isolated, and grounded to keep it out of our bodies, even when we have to touch the controls to turn those devices on & off.

Food: Don’t even get me started on the hazards of ingesting plant & animal product that used to live outside and was processed for transport hundreds, or sometimes thousands, of miles away.  It’s a wonder any of us have made it this long.  Well, except for the development and rigorous implementation of food safety and sanitation practices & policy.

Working with compressed air is no different.  A typical plant compressed air system will operate at about 100psig.  That literally means that there is ONE HUNDRED POUNDS OF FORCE being exerted on EACH AND EVERY SQUARE INCH of the inside of the pipes, hoses, tanks, etc., in the system.  If you don’t keep it under control, you can have some serious problems.  Fortunately, there are simple, straightforward, and easily accessible ways to do that.

This is not going to be a comprehensive guide, but let’s start with:

Design: Your piping and components have to be the proper pressure rating.  We’ve got some good piping information on our websiteAlso, keep your vehicle well maintained, periodically check your electric devices for frayed cables, and look at your meat packages’ labels for a USDA stamp and “use by” date.

Our Compressed Air Piping web page is a valuable resource for safety AND efficiency (left.) Don't rely on smell or color; food package labels are your best indication of food safety (right.)

Our Compressed Air Piping web page is a valuable resource for safety AND efficiency (left.) Don’t rely on smell or color; package labels are your best indication of food safety (right.)

Controls: Make sure you’re using your compressed air safely.  OSHA Regulation 1910.242(b) governs the use of compressed air when used for cleaning purposes…it limits you to no more than 30psi of downstream, static pressure at the discharge of your blow off device.  EXAIR Intelligent Compressed Air Products comply with this regulation, by design.  Also, watch your speed on the highway, don’t plug too many strands of Christmas tree lights in to one outlet, and always cook chicken to an internal temperature of at least 165F (73.9C)

EXAIR Super Air Nozzles are fully OSHA Compliant - certificated available upon request (left.) Your power strip and Christmas tree light strands should both be labeled with their amperage ratings. Check these to make sure you don't overload the circuit (right.)

EXAIR Super Air Nozzles are fully OSHA Compliant – certificate available upon request (left.) Your power strip and Christmas tree light strands should both be labeled with their amperage ratings. Check these to make sure you don’t overload the circuit (right.)

Personal Protective Equipment: Any time you’re working with compressed air, you should be wearing eye protection and using appropriate chip guards to keep flying debris from coming back at you.  Certain applications may require more safeguards…check with your compliance coordinator or supervisor to make sure.  Also, don’t shift out of ‘park’ without your seat belt fastened, take care to unplug any appliance before servicing it, and don’t skimp on a decent pair of oven mitts if you plan on making a lot of baked goods.

EXAIR Safety Air Guns can be fitted with Chip Shields for OSHA Compliance (left.) Oven mitts come in all shapes & sizes - it would be illogical to reach for that lasagna without them (right.)

EXAIR Safety Air Guns can be fitted with Chip Shields for OSHA Compliance (left.) Oven mitts come in all shapes & sizes – it would be illogical to reach for that lasagna without them (right.)

EXAIR has been making quiet, efficient, and safe compressed air products for 34 years now.  If you ever have any questions about the safe use of compressed air, give us a call and ask for an Application Engineer.  No; compressed air isn’t safe, in and of itself…but it CAN be used safely…and that’s the important part.

Russ Bowman
Application Engineer
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ef2d_star_trek_oven_mitt picture courtesy of Cozinhando Fantasias

d2590-1 picture courtesy of US Department of Agriculture

Holiday fire safety – Power strip overloaded picture courtesy of State Farm

Creative Commons Attribution 2.0 Generic License

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
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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

 

FREE TESTING!!!! EXAIR’s Award Winning Efficiency Lab Saves Air and Money

EXAIR’s Efficiency Lab is now the “award-winning Efficiency Lab”. Thank you to Environmental Protection Magazine for recognizing the value and importance of this EXAIR service.

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I have blogged about this many times and we continue to help customers by using our free Efficiency Lab service that EXAIR provides to customers throughout the USA.  The EXAIR Efficiency Lab allows customers to send in their existing blow off device and we will test it for compressed air consumption, sound level, and force.  Ideally we try to take these measurements at the same operating pressure that is being supplied in the field so that we can compare it to an EXAIR product and offer the customer the best solution, the safest solution, and an engineered solution capable of saving them money through air savings and effectiveness.

Here is a recent example of  a product sent in by a customer concerned with compressed air consumption and safety of their people. The  hose they sent in was actually designed to be used with liquid coolants and was a very large consumer of compressed air.

A flexible blow off with .495" openings. Designed for liquid but used for compressed air. Enormous waste of air and a huge safety risk.

A flexible blow off with .495″ openings. Designed for liquid but used for compressed air. Enormous waste of air and a huge safety risk.

The hose shown above was being used at 40 psig inlet pressure.  The device is not OSHA compliant for dead end pressure, nor does it meet or exceed the OSHA standard for allowable noise level exposure.   The hose was utilizing 84.64 SCFM of compressed air and was giving off 100.1 dBA of sound.

OSHA Noise Level

As seen in the chart above, an employee is only permitted to work in the surrounding area for 2 hours a day when exposed to this noise level.   The amount of force that the nozzle gave off was far more than what was needed to blow chips and fines off the part.   The EXAIR solution was a model 1002-9230 – Safety air Nozzle w/ 30″ Stay Set Hose.

The EXAIR products were operated at line pressure of 80 psig which means they utilized 17 SCFM of compressed air and gave off a sound level of 80 dBA.  On top of saving over 67 SCFM per nozzle and reducing the noise level to below OSHA standard, the EXAIR engineered solution also meets or exceeds the OSHA standard for 30 psig dead end pressure.   In total this customer has replaced 8 of these inefficient lines and is saving 541 SCFM of compressed air each time they activate the part blowoff.

If you would like to find out more about the EXAIR Efficiency Lab, contact an Application Engineer.

We look forward to testing your blow off and being able to recommend a safe, efficient, engineered solution.

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

 

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