Is It Safe To Use Compressed Air?

Think about it…compressed air is, by definition, gas under pressure: potential (stored) energy.  This energy is intended to do work, like operation of pneumatic tools, actuation of pneumatic cylinders, debris removal with an air gun or blow off device, and (even though I haven’t done it in a while) my personal favorite:

High pressure compressed air is meticulously made, prepared, and stored to ensure the number of surfaces equals the number of dives.

Uncontrolled, unplanned, or accidental releases of stored energy (regardless of the source) are inherently dangerous, and great care must be taken to guard against such incidents.  This is accomplished, primarily, in three areas:

*Operation.  This might be the most prevalent, because it involves the greatest number of personnel (e.g., everyone) as well as the ways compressed air is used (e.g., all of them.)  It’s also the area where the most involved people (the operators) have the most control:

  • Personal protection.  Don’t even think about operating a compressed air device without eye protection.  Ever.  Hard stop.  Also, if the operation involves flying debris, a full face shield, long sleeves, gloves, etc. might be called for.  Hearing protection may be required as well…keep in mind, even if an engineered device (like any of EXAIR’s Intelligent Compressed Air Products) generates a relatively low sound level, the impingement noise of the air flow hitting the object can reach dangerous levels.
  •  Personnel cleaning is prohibited.  The risk of injury to the eyes, respiratory system, and other parts is just too great to rely on personal protective equipment that’s designed for use while discharging compressed air AWAY from the body.  While this is expressly prohibited in certain situations, OSHA has long recognized it as good practice for all industries.
  • No horseplay.  ’nuff said.  Plenty of better ways to have fun at work.

*Design.  This one usually has the advantage of being traceable to a small number of people, and is also the one that’s most likely to be documented.  This is where it starts…if the system is designed to fail, it doesn’t matter how much care the operators take:

  • Supply lines, fittings, and hoses must be rated for use with compressed air, up to and exceeding the maximum discharge pressure of the air compressor.
  • This goes for any tools, blow off devices, components, etc., serviced by the air system.  The only thing worse than a component failing is a component failing in your hand.
  • Shut off valves should be located as close as practical to point(s) of operation.  This allows you to quickly secure the flow of compressed air to a failed component, hose, etc., and prevent further damage or risk of injury.
  • Hoses shouldn’t be run across the floor, where they can become a trip hazard or subject to damage from stepping on them.   This is a surefire way to find out the value of shut off valves (see above.)

*Product specification.  Or, more simply put, using the right tool for the job.  A broader discussion could include efficiency and performance, but we’ll stay within the confines of safety for the purposes of this blog:

  • Be mindful of dead end pressure.  Blow off devices, especially hand held ones like air guns, are oftentimes fitted with a simple open-end discharge.  If this is pushed into a part of the body, the pressurized air can break the skin and cause an air embolism.  This is a serious injury, and can be fatal if it reaches the heart, lungs, or brain.
    • This is a key consideration to OSHA Standard 1910.242(b), which limits the downstream pressure when compressed air is used for cleaning to 30psi.
    • EXAIR products are compliant with this Standard by design…there’s always a relief path for the air pressure; they can’t be dead ended.
Because the compressed air exits through a series of holes, recessed between a ring of fins, any attempt to block the air flow will simply send it in another direction.
  • Harmful sound levels are a consideration as well.  As stated above, hearing protection is required in many cases, but sound levels can be mitigated through the use of engineered products.  EXAIR Intelligent Compressed Air Products, as a result of their high entrainment, generate a boundary layer of air flow that leads to dramatically lower sound levels than a similar-sized open end blow off device.

If you’d like to explore ways to make your compressed air system safer, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Cleaning Glass After a Cutting Machine, Super Air Knives to the Rescue

Glass cutting machine

A glass cutting facility was having issues with small shards of glass leaving the cutting machine.  After scribing and breaking individual panes, small pieces of glass would come apart from the edges of the glass.  These glass fragments would go downstream causing cuts on transport wheels as well as creating blemishes in the surface of the glass.  They needed a non-contact way to clean the glass as the panes left the cutting machine.

Their operation started with a 156” (3.96m) wide sheet of glass placed at the front of the cutting machine.  The glass was moved into the machine where it would scribe different dimensions and sizes to minimize any scrap.  As the machine was scribing, a protective separator would close off the cutting machine to protect the operators.  Once finished, the protective separator would open, allowing the glass sheet to exit on the other side of the machine.  As the glass was coming out, a break device would “crack” the glass panes on the scribed lines.  They wanted to clean the surface as the glass sheet was coming out to keep the fragments in the machine.

EXAIR Super Air Knife model 1100108

EXAIR has always been the leader in manufacturing the longest air knives in the industry.  The EXAIR Super Air Knives can be manufactured up to 108” (2.74m) long in one continuous length.  But, for this application, we had to tackle it in a different manner to reach across the entire width of 156” (3.96m).  EXAIR had a solution, the model 110900 Coupling Bracket Kit.  This can combine aluminum Super Air Knives for additional length.  It has all the hardware to securely attach the Super Air Knives end-to-end to get a continuous air flow along the entire length.  With the Coupling Bracket Kit, I recommended a model 110072, 72” (1.83m) long aluminum Super Air Knife with a model 110084, 84” (2.13m) aluminum Super Air Knife.  The customer was now able to clean the entire section of glass just in front of the exit of the cutting machine.  With the air knives directed to blow at a slight angle in the counter-flow direction, this non-contact form of cleaning was able to keep the shards inside the machine without scratching the surfaces.

Air Knife Coupling Bracket Kit

The Super Air Knives are designed to be the most efficient air knives in the market place.  It has a 40:1 amplification ratio which entrains 40 parts of ambient air to every 1 part of compressed air.  So, it will save you compressed air which in turn, will save you money.  Here at EXAIR, we like to go one step further for our customers.  EXAIR offers an Optimization product line to save the customer even more money, to reduce even more waste, and to become even more energy efficient.  For this customer above, I recommended an Electronic Flow Control, EFC.  This uses a photoelectric sensor to turn on a system only when compressed air is needed.  It is a small PLC unit with a timer control.  I recommended the model 9064-2 which has two solenoid valves to operate each Super Air Knife.  The photoelectric sensor can be adjusted for light and dark object, but for glass, we had to look for an alternative way.  I was able to have the customer place it on the protective separator.  Now, the Super Air Knives will remain turned off until after the scribing was completed. When the separator moved up, it would trigger the timing operation of the EFC.  By adding the EFC to their system, they were able to reduce the amount of compressed air by one-half.

click on picture for mor information

If you have a wide area that needs to be blown off, cooled, or dried; EXAIR may have a solution for you.  For the customer above, EXAIR was able to combine Super Air Knives with optimization for an efficient and effective way to clean a wide surface.  If you would like to discuss a solution for your “wide” application, you can contact an Application Engineer at EXAIR to discuss.

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

Super Air Knife Cools Laminated Packaging Material

I recently worked with one of our distributors on a Super Air Knife application for a manufacturer of flexible packaging material. They create the plastic material that is commonly wrapped around the outside of a wide variety of different containers. The material exits the laminating machine at about 129°F (54°C) and must be cooled to close to room temperature before it is able to be rolled without the material sticking together.

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Model 110012, positioned to maximize counter-flow

They performed a test with a Model 110012, recording the temperature after the knife and determined that it would be suitable for them. Prior to using the Super Air Knife, they had been using a series of fans to cool down the material. This worked to some degree, but they had been experiencing quality issues as a result of inadequate levels of cooling and were forced to slow down the laminating machine in order to compensate. By implementing the Super Air Knife, they were able to cool the material down to ambient temperatures without having to slow production. As an added measure, they ordered a second knife to install on the underside to further decrease the temperature of the material.

sak_cooling
Graph showing the effectiveness of a Super Air Knife vs. fans or no cooling method.

The laminar airflow of the Super Air Knife is critical to the success of any cooling application. A fan “slaps” the air which provides random spikes of air at moderate velocities. The uniform, high velocity, laminar sheet of air from the Super Air Knife, in addition to the low compressed air consumption, makes it a much more effective cooling method than fans. The design of the Super Air Knife allows it to entrain ambient air at a rate of 40:1, maximizing the force and flow from the knife while keeping compressed air usage to a minimum.

super-air-knife-flow
The design of the Super Air Knife allows it to entrain air from the top and bottom, creating a 40:1 air amplification ratio.

Super Air Knives are available in a range of different materials and sizes. From stock EXAIR carries knives from 3”-108” in Aluminum, 303 Stainless Steel, 316 Stainless Steel, and 3”-54” in PVDF (Polyvinylidene Fluoride) for superior resistance to highly corrosive materials. In addition to being an excellent tool for cooling, the Super Air Knife can solve a wide range of drying and blowoff applications. If you have an application that would be better served with one of EXAIR’s Super Air Knives, reach out to us today and get yours on order! We ship same day from stock with orders received by 3:00 pm EST, stop wasting time with ineffective cooling or blowoff methods!

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

Super Air Knife Coupling Kit Helps Customer Save Money and Increase Productivity!

I was recently contacted by a manufacturer of specialty food products that was looking to increase productivity on one of their packaging lines. In order to do so, they needed a longer Super Air Knife.

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Model 110012SS-316 Super Air Knife

They manufacture a variety of different products, but this application was involving small snack-size blocks of cheese. They’re placed into individual plastic containers and before they seal the packaging any residual particles must be blown off or it will affect the seal. Any residual particles of cheese around the container would allow air to come into contact with the product and affect shelf-life.

In the current setup, they were using EXAIR’s Model 110012SS-316 a 12” 316 grade Stainless Steel Super Air Knife and the Model 9060 Universal Mounting System. They wanted to add in an additional two rows of cheese to help increase throughput. To do so, he needed an overall width of 18”. We do have an 18” available from stock, but rather than having a spare 12” model lying around he wanted to try and utilize what he had without having to purchase an entirely new knife.

uakmb
Model 9060 Universal Mounting System

Fortunately, EXAIR’s Super Air Knives can be coupled together to create a wide variety of different lengths. From stock, the Super Air Knife is available from 3”-108”. With the help of a Super Air Knife Coupling kit, we can achieve much longer lengths. In this case, although we did have an 18” knife available, we could also couple the existing 110012SS-316 (12”) with our Model 110006SS-316 (6”). This option was a bit cheaper than going with a new knife, and still allowed them to utilize the 12” that they already had.

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Coupling Kit for Aluminum Super Air Knives

While this isn’t the typical place we’d recommend a coupling kit, it was an option that allowed the customer to save a bit of money but still get the same effect that they’d achieve with the 18” single piece knife. We also manufacture a wide variety of custom knives per customer specifications. If you’ve got an odd application that you don’t think is best served by a stock offering, give us a call. An Application Engineer will be happy to take a look at your application and help recommend the most suitable product.

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

Super Air Knife with a Plumbing Kit Removes Gypsum from a Conveyor Belt

Plumbing Kits

A gypsum facility was having issues in losing powder from the tailings in their conveying system.  The conveyor moved gypsum from their processing plant to an outside silo bin location for loading and transportation.  The conveyor that they used was 60” wide.  As the conveyor went around the end to dump the gypsum powder, some of the material would stick to the belt and collect on the floor underneath.  Depending on production rates, they would have to stop the operation to clean up the floor which added additional hours for custodial work.  The customer sent a picture of the problem and wondered if EXAIR could help them with this application.

The facility did an annual cost projection to determine the loss of money from the gypsum material collecting under the conveyor.  The custodial cost to clean up the excess powder was roughly $45,000/year.  The unscheduled downtime was estimated at 115 hours per year.  (They did not share the loss of dollars in production to EXAIR.)  But it was large enough that they needed a solution from EXAIR.  (The photo below is similar to the same application as written by Lee Evans: “EXAIR Super Air Knives Improve Process in an Aluminum Rodding Shop“.)

Powder collecting under conveyor

I suggested a model 110260PKI Super Air Knife Kit for this application.  The Super Air Knife was 60” in length to cover the conveyor belt.  The kit included a filter, a regulator, and a shim set to “dial” in the minimum amount of force to remove the material.  This gives the customer the most flexibility when using an EXAIR Super Air Knife.  The “PKI” suffix at the end of the model number indicates our Plumbing Kit.  This kit which is Installed on the Super Air Knife allows for ease of installation to compressed air connections and it also allows for the proper airflow to get a consistent blow-off across the entire length of the Super Air Knife.

At EXAIR, we pride ourselves in energy efficiency.  Compressed air is expensive to make, so why not use it as efficiently as you can?  The Super Air Knife has a 40:1 amplification ratio which allows 40 parts of ambient “free” air for every 1 part of compressed air.  And, with the “dirty” environment at the gypsum facility, the Super Air Knife would not be affected as they do not require a motor that can fail or a maintenance program to perform.  After installing the model 110260PKI, the gypsum powder was no longer collecting on the floor underneath.  If we look at the cost of removing the hourly rate of the custodian, the Return on Investment, ROI, was only 27 days (and this did not include the increase in production rates).

Spillage is wasteful, costly, and time consuming to cleanup.  If you have excess waste from your conveying system, EXAIR will have the product to help you.  For the gypsum facility above, the Super Air Knife Kit made it possible to increase production efficiencies with a short ROI.  You can contact an Application Engineer to review your application and see if we can improve your conveying operation.

John Ball

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

Super Air Knife Cleans Baking Pans

A few weeks back I was contacted by a large baking company who was looking for a better way to pre-clean their cake and muffin pans before sending them to a wash cycle. After the pans exit the oven, an operator places the baked goods on a cooling conveyor then uses an air gun to blow out the residual crumbs. The pans are then placed on a separate conveyor and sent through a washer. The manual operation was taking a lot of extra time which resulted in reduced production.

Muffin Pan

After further discussion, I recommended they use our 24″ Super Air Knife. The Super Air Knife produces an even, high velocity curtain of air across the entire length of the knife which would provide a uniform blowoff of the pans, eliminating the manual cleaning.  Super Air Knives are extremely efficient and quiet. Operating at 80 PSIG, using a 40:1 amplification rate of entrained ambient air to compressed air consumed, they require only 2.9 SCFM per inch of knife length while maintaining a low sound level of only 69 dBA and produce a velocity of 11,800 feet per minute.

Efficient way to clean, dry or cool parts, webs or conveyors.

The Super Air Knives are available in lengths from 3″ up to 108″ in single-piece construction and offered in aluminum, 303ss or 316ss construction, they are the perfect choice for small scale or wide coverage blowoff applications. To discuss a particular application or for help selecting the best EXAIR product to fit your need, contact an application engineer at 800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

Muffins Anyone? photo courtesy of Amy via creative commons license.

How a Super Air Knife Helps with Metal Etching

Etching Machine

A company had a process where they were etching metal components with an acid bath.  The system consisted of four baths where the metal parts would be dipped.  The four baths consisted of a wash, rinse, acid bath, and rinse again.  The automated system was contained inside an enclosed booth; and, once the parts were placed inside a 24” (610mm) X 18” (457mm) basket, a sliding door was closed to initiate the operation.  The timing sequence consisted of the basket being dipped into each bath for a certain length of time.  Between each bath cycle, the basket would be raised above the solution, and an open pipe blow-off would remove excess liquid from the part with compressed air.   They complained that the parts were not getting dry enough, and cross-contamination was causing process problems.  The acid bath was becoming more neutral and the effectiveness of the etching was being sacrificed.  The rinse water was becoming more “soapy” after the cleaning bath and more acidic after the acid bath.  Overall, they had to replace every one of the bath solutions which caused shut-downs and extra expense.

From similar applications, I was able to recommend a great solution.  Because of the acidic solution and corrosive environment, I recommended two stainless steel Super Air Knives, model 110024SS.  They are manufactured in 303 stainless steel.  EXAIR also offers 316 stainless steel as well as PVDF for more acidic or caustic etching.  Instead of using the open pipes to blow off the parts, the customer could replace them with the Super Air Knives.  They can easily be mounted above the front and back of the basket, blowing at a downward angle toward the dip tank.  The two Super Air Knives would remove the liquid solution from the parts as well as the basket to put back into the same dipping tank.  The more solution that is removed, the less liquid that will transfer from one solution to the next; thus, reducing cross-contamination dramatically.

After installing the model 110024SS Super Air Knives in their system, they started to see a vast improvement in their etching process.  The etching acid was able to be used roughly 40% longer as compared to the prior method.  As an added feature, the Super Air Knives decreased the time to blow off the parts as they can be adjusted for optimum cleaning.  Less waste and faster production times were how the EXAIR Super Air Knives helped the customer above.  If you have a similar application and want to discuss how we can improve your dipping process, please speak to one of our Application Engineers.  We’ll be happy to help.

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