EXAIR Standard Air Knife Overview

EXAIR manufactures a variety of different air knives in several different materials of construction. For the purposes of this blog, I’ll be discussing the Standard Air Knife. EXAIR’s Standard Air Knife was the first rendition of the Air Knife family. The Standard Air Knife utilizes what’s known as the Coanda Effect, or the propensity of a fluid to adhere to a curved surface. The airflow from the Standard Air Knife exits the nozzle outlet and ends up perpendicular to the outlet. This air motion that is created also allows the knife to entrain ambient air at a rate of 30:1, 30 parts ambient air to one part compressed air, which maximizes the force while minimizing compressed air consumption.

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Standard Air Knife

Due to this air entrainment, air savings of 40%-90% are possible when replacing homemade blowoff devices such as drilled or slotted pipe. Return on your investment is seen typically within weeks rather than months or years.

In addition to significant air savings, the Standard Air Knife also dramatically reduces “wind shear” by gradually introducing the entrained air into the primary airstream. The exiting air is also laminar, not turbulent. These two features help cut noise levels in HALF! With drilled pipes or open tube jets, there’s little to no air amplification and the sound levels are extremely high. These sound levels typically will be far outside of OSHA’s acceptable level of noise for operators. Fines can be handed out by OSHA under directive 29 CFR 1910.95.

The Standard Air Knife is available in lengths from 3”-48” in both aluminum and Type 303SS. They’re an excellent choice for applications such as blowing or removing debris, drying or cooling parts, or environmental separation. ¼ NPT female ports are located at either end of the knife and the force and flow through the knife is adjustable. For gross adjustments to the airflow, we offer shim sets that contain a .001”, .003”, and .004” shim for aluminum or (3) .002” shims for the stainless steel knives. Shims can be stacked together to create even more flow, or in the case of the aluminum knives the .001” shim can be installed to cut the flow and force in half. In addition to offering the shim sets, a pressure regulator can be installed right at the point of use to “dial in” the exact pressure that you need for the application.

Standard Air Knife Kit
Standard Air Knife Kit

If you have drilled or slotted pipe blowoffs in your facility, you’re simply leaving money on the table through high energy costs. Take advantage of the unconditional 30 day guarantee for all stock products and see just how much you can save with EXAIR’s Standard Air Knife.

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

The Value Of A Pressure Regulator At Every Point Of Use

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EXAIR Pressure Regulator

To understand the value of a having a Pressure Regulator at every point of use we should start with identifying the two types of Pressure Regulators, Direct Acting & Pilot Operated.  Direct Acting are the least expensive and most common (as shown above), however they may provide less control over the outlet pressure, especially if they are not sized properly.  However when sized properly they do an outstanding job.  Pilot Operated Regulators incorporate a smaller auxiliary regulator to supply the required system pressure to a large diaphragm located on the main valve that in turn regulates the pressure.  The Pilot Operated Regulators are more accurate and more expensive making them less attractive to purchase.  The focus of this Blog will be on the Direct Acting Pressure Regulator.

The Direct Acting Pressure Regulator is designed to maintain a constant and steady air pressure downstream to ensure whatever device is attached to it is operated at the minimum pressure required to achieve efficient operation.  If the end use is operated without a regulator or at a higher pressure than required, it result’s in increased air demand and energy use. To clarify this point, if you operate your compressed air system at 102 PSI it will cost you 1% more in electric costs than if the system was set to run at 100 PSI! Also noteworthy is that unregulated air demands consume about 1% more flow for every PSI of additional pressure.  Higher pressure levels can also increase equipment wear which results in higher maintenance costs and shorter equipment life.

Sizing of the Air Regulator is crucial, if it is too small to deliver the air volume required by the point of use it can cause a pressure drop in that line which is called “droop”.  Droop is defined as “the drop in pressure at the outlet of a pressure regulator, when a demand for compressed air occurs”.  One commonly used practice is to slightly oversize the pressure regulator to minimize droop.  Fortunately we at EXAIR specify the correct sized Air Regulator required to operate our devices so you will not experience the dreaded “droop”!

Standard Air Knife Kit
EXAIR Standard Air Knife Kit Which Incudes Shims, Properly Sized Pressure Regulator & Filter Separator

Another advantage to having a Pressure Regulator at every point of use is the flexibilty of making pressure adjustments to quickly change to varying production requirements.  Not every application will require a strong blast sometimes a gentle breeze will accomplish the task.  As an example one user of the EXAIR Super Air Knife employs it as an air curtain to prevent product contamination (strong blast) and another to dry different size parts (gentle breeze) coming down their conveyor.

EXAIR products are highly engineered and are so efficient that they can be operated at lower pressures and still provide exceptional performance!  This save’s you money considering compressed air on the average cost’s .25 cents per 1000 SCFM.

Super Air Knife Performance
EXAIR Super Air Knife Performance Specifications At 5 Different Pressures.

If you would like to discuss Air Regulators or quiet and efficient compressed air devices, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
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Safety Air Guns – Using Engineered Air Nozzles For High Performance

Inexpensive air guns can be picked up just about anywhere, and you generally get what you pay for. Most will be very noisy and waste lots of compressed air.  And many will be unsafe, violating two of OSHA’s standards put in place to protect worker safety. The first is Standard 29 CFR 1910.95(a) which sets limits to the maximum noise exposure, and the second is Standard 29 CFR 1910.242(b) which says that the nozzle cannot be dead-ended, or exceed a 30 PSIG pressure limit.

These guns may seem like a perfect fit for a handheld blowoff application. The truth is, the cost saved up front will easily be paid throughout the cost of ownership.  This is due to the lack of an engineered nozzle which meets and exceeds the OSHA standards mentioned above.   The “cheap” guns often have a cross drilled hole to meet or exceed the OSHA standard for dead-end pressure. While this may be true, it causes a large wind sheer which escalates noise levels to well over the allowable noise level exposure set by OSHA.  These tips sometimes offer large force outputs because they are equivalent to an open pipe.  We have publicized numerous times about how an open pipe blow off does not permit pressure to be utilized all the way to the point of blowoff, and is also a waste of energy.

In order to determine how much compressed air your current blow guns utilize, the level of noise they product, and the sound level they produce, consider taking advantage of the EXAIR Efficiency Lab.  The Efficiency Lab is a free service that you can read more about here.

An EXAIR Safety Air Gun is engineered and designed to comply both of the OSHA standards mentioned above, ensuring safe operation for company personnel.  On top of the safety designed into the guns, we also ensure all of our guns are efficient by offering only engineered nozzles on them.

EXAIR offers (4) types of Safety Air Guns – the VariBlast, the Soft Grip, the Heavy Duty, and the Super Blast.  Each type of Safety Air Gun is offered with a plethora of nozzles, as well as varying length extensions, with or without the Chip Shield.

Safety Air Guns
The VariBlast, Soft Grip and Heavy Duty Style of Pistol Grip Safety Air Guns
Super Blast
The Super Blast Style of Safety Air Gun

 

We invite you to try out an EXAIR Safety Air Gun, and get the free 1″ Wide Flat Super Air Nozzle as a bonus. Click here for more details about this special promotional offer.

To discuss your application and how an EXAIR Intelligent Compressed Air Product can improve your process, feel free to contact EXAIR, myself, or one of our other Application Engineers. We can help you determine the best solution!

Brian Bergmann
Application Engineer

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Compressor Control – A Way to Match Supply to Demand

Rarely does the compressed air demand match the supply of the compressor system. To keep the generation costs down and the system efficiency as high as possible Compressor Controls are utilized to maximize the system performance, taking into account system dynamics and storage. I will touch on several methods briefly, and leave the reader to delve deeper into any type of interest.

air compressor

  • Start/Stop – Most basic control –  to turn the compressor motor on and off, in response to a pressure signal (for reciprocating and rotary type compressors)
  • Load/Unload – Keeps the motor turning continuously, but unloads the compressor when a pressure level is achieved.  When the pressure drops to a set level, the compressor reloads (for reciprocating, rotary screw, and centrifugal type)
  • Modulating – Restricts the air coming into the compressor, as a way to reduce the compressor output to a specified minimum, at which point the compressor is unloaded (for lubricant-injected rotary screw and centrifugal)
  • Dual/Auto Dual – Dual Control has the ability to select between Start/Stop and Load /Unload control modes.  Automatic Dual Control adds the feature of an over-run timer, so that the motor is stopped after a certain period of time without a demand.
  • Variable Displacement (Slide Valve, Spiral Valve or Turn Valve) – Allows for gradual reduction of the compressor displacement while keeping the inlet pressure constant (for rotary screw)
  • Variable Displacement (Step Control Valves or Poppet Valves) – Similar effect as above, but instead of a gradual reduction, the change is step like (for lubricant injected rotary types)
  • Variable Speed – Use of a variable frequency AC drive or by switched reluctance DC drive to vary the speed of the motor turning the compressor. The speed at which the motor turns effects the output of the system.

In summary – the primary functions of the Compressor Controls are to match supply to demand, save energy, and protect the compressor (from overheating, over-pressure situations, and excessive amperage draw.) Other functions include safety (protecting the plant and personnel), and provide diagnostic information, related to maintenance and operation warnings.

If you would like to talk about compressed air or any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Compressed Air and Safety

Warning

Compressed air is generally considered the fourth utility in industrial, commercial and back-yard settings.  It is used to power pneumatic equipment, cleaning surfaces, conveying materials, etc.  The compressor reduces the volume inside a chamber to increase the pressure.  The compressed air typically is contained in a reservoir tank for distribution to pneumatic equipment and devices.  Since air is a compressible fluid it has stored energy; and, if not used properly, it can be hazardous.  Most people perceive compressed air as harmless, but this is untrue.  It can be very dangerous.  Here are some potential risks when using compressed air:

  1. If the air pressure against the skin becomes greater than 30 PSI, air can penetrate through the membrane and cause an embolism which could be fatal.  The term used is Dead-End pressure, any end-use nozzle or blowoff product cannot exceed 30 PSI dead-end pressure.
  2. Hearing damage can occur from exposure to loud noises from compressed air exhausting from pneumatic equipment or devices.
  3. Proper use of Safety Air Guns and Safety Air Nozzles is a must. They should not be modified or tampered with.  For example, tying the trigger on an air gun for continuous blowing or modifying the nozzle to get a different blowing pattern.
  4. Compressed air can generate high velocities which can shoot chards of debris. The accelerated fragment can injure any part of the body even from bounce-back.
  5. If the air pressure is higher than the recommended rating for the equipment, uncontrolled eruptions can occur which can send broken pieces everywhere.
  6. When air hoses or lines are laying on the floor, near pinch points, or degrades from the environment, a break can occur causing unrestrained hose “whipping”.

Some safety precautions can be followed in your area when using compressed air products.  They may seem basic, but they are commonly overlooked.

  1. Verify that all compressed air components are rated to be used for the maximum line pressure.
  2. Use shut-off valves nearby to isolate the system from the main compressed air line.
  3. Have general inspection on your compressed air system to check for pipe degradation, leaks, faulty pneumatics, etc.
  4. When you go to repair items attached to the compressed air line, make sure to use proper lockout procedures to isolate and remove the hazardous energy.
  5. Remember that compressed air is not a toy and use proper PPE when required.
  6. If any pneumatically operated product is damaged, remove it from service and either repair it or replace it.
EXAIR Products

In 1970, Occupational Safety and Health Administration, OSHA, was enacted by the Department of Labor.  This organization was created “to ensure safe and healthful working conditions for working men and women”.  They created a set of laws and standards that they enforce with heavy fines and reoccurring visits if not followed.  The Department of Labor lists these laws under title 29 in the Code of Federal Regulations (CFR).  For general industry, these safety regulations are under part 1910 of 29 CFR.  To give a few examples, 29 CFR 1910.242b gives the explanation about dead-end pressure.  Under 29 CFR 1910.95a shows the maximum allowable noise exposure.  The reason that I noted these two OSHA standards as they are commonly overlooked with Safety Air Guns, and commonly fined by OSHA for improper nozzles.

Safety is everyone’s responsibility, and EXAIR products can be a key.  If you would like to discuss how to improve your workplace, you can contact an Application Engineer at EXAIR.     Because hazards and fines can be detrimental to your company when it comes to compressed air safety.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

 

Photo: Attention Warning Sign by Peter-LomasCreative Commons: CCO

 

 

EXAIR’s Flat Nozzles: Safe, Reliable, and Efficient

Here on the EXAIR Blog we frequently discuss dead-end pressure as explained in OSHA Standard 1910.242(b). This directive states that the when compressed air is used for cleaning purposes, the dead-ended pressure must not exceed 30 psig. When pressures greater than this occur, there is potential for an air embolism. This animation shows and explains how an air embolism can affect the body.

EXAIR’s Flat Nozzles adhere to this OSHA directive. The Flat Nozzles consist of three primary components: the body, the cap, and the shim. The thickness of the shim will dictate the flow and force through the nozzle and can be easily adjusted. The cap slightly protrudes from the body and shim, creating a gap when it is pressed up onto the skin. By ensuring that there is always an avenue for that air to escape, there is no potential for it to be dead-ended.

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From top to bottom: Model 1126, 1126SS, 1122, and 1122SS

EXAIR’s flat nozzles are available in two sizes: 1” and 2”. Each size has a shim set that can be purchased for adjusting both the flow and force from the nozzle. These nozzles are available in both zinc/aluminum alloy as well as 316 grade Stainless Steel. They can be used by themselves, installed on our Safety Air Guns, or in conjunction with our Stay Set Hoses that allow for easy re-positioning.

You may have seen (or used) the plastic flat nozzles that come in a variety of different colors. EXAIR’s flat nozzle is a safe, efficient, and more robust replacement that will maintain a similar airflow pattern at a dramatically reduced operating cost. Where plastic nozzles may become damaged or break off, the rigid construction of EXAIR’s Flat Nozzle will not. In addition to be safe, durable, and reliable, EXAIR’s flat nozzles also offer a reduced sound level compared to these styles of nozzle. Reducing sound is another directive that OSHA 29 CFR 1910.95 covers. If you’re using an unsafe nozzle in your facility, OSHA can quickly begin assessing fines for each violation. They don’t announce their visits beforehand, so make sure you do your due diligence and assess your compressed air blowoff products yourself!

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EXAIR 2″ Flat Super Air Nozzle “blows” away the competition!

If you would like to discuss how to make your compressed air use safer and more efficient, give us a call. Our team of highly-trained Application Engineers is standing by, ready to help you make the switch to an Intelligent Compressed Air Product.

Tyler Daniel
Application Engineer

E-mail:TylerDaniel@exair.com
Twitter:@EXAIR_TD

OSHA Standard 1910.242(b) – Dead-End Pressure and Chip Guarding Explained

OSHA Standard 1910.242(b) discusses the use of compressed air for cleaning and blowoff. It states that the use of compressed air for cleaning purposes is prohibited if the dead-ended pressure exceeds 30 psig. This phrase means the downstream pressure of the air nozzle or gun, used for cleaning purposes, will remain at a pressure level below 30 psig for all static conditions. In the event that dead ending occurs, the static pressure at the main orifice shall not exceed 30 psi. If it does exceed this pressure, there is a very high potential for it to create an air embolism. An air embolism, left untreated, can quickly impede the flow of blood throughout the body. This can lead to stroke, heart attack, and sometimes death. Take a look at the animation below to see how an air embolism can affect the body.

With this in mind, there are only two options for staying within compliance of this standard. Either install an engineered solution that will reduce the air pressure to less than 30 psig if dead-ended, or regulate the pressure below 30 psig. For the vast majority of operations, regulating the input pressure below 30 psig is useless. The force and flow from the nozzle at this pressure is greatly reduced and likely not enough to be effective in most applications. All of EXAIR’s Safety Air Guns are designed so that the flow cannot be dead-ended. The fins on the Super Air Nozzles are not only useful in amplifying the force by drawing in ambient air, but they also prevent an operator from completely obstructing the airflow.

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The fins of the Super Air Nozzle allow air to escape and prevent dead-end pressure from exceeding 30 psig.

In addition to being concerned about dead-end pressure, OSHA 1910.242(b) also states that compressed air used for cleaning should include effective chip guarding. By this, they mean that some method or equipment must be installed that will prevent chips and particles from coming back into the eyes or skin of the operator. In addition to offering OSHA compliant nozzles and guns, EXAIR also has Chip Shields that can be installed onto any of our Safety Air Guns. The polycarbonate shields protect the operator from any flying debris while performing a drying or blowoff operation. Simply add a “-CS” to the end of any Safety Air Gun Model number to have a Chip Shield installed on the gun.

1210peek-cs
EXAIR’s Model 1210-PEEK-CS with Chip Shield

The Occupational Safety and Health Act of 1970 does not contain any provisions that allow for the approval or endorsement of equipment. Alteration or the misapplication of what was once a safe piece of equipment would create a dangerous scenario that is out of the control of the original manufacturer. Any nozzles or guns marketed as “OSHA approved” should immediately throw up a red flag. Identifying and implementing a safe, OSHA compliant solution rests in the hands of the manufacturer themselves. If you’ve got questions about compressed air safety or have an existing blowoff in place that does not adhere to this OSHA directive, give us a call. We’ll be sure to recommend a solution that will keep your operators and wallets safe!

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