Cold, Dry Climates are a Recipe for Static Problems

A few weeks ago, for the first time this season, I had to scrape ice off of my windshield before heading to work. Living in the Midwest, this is the first sign that winter is coming. The colder climate doesn’t just alter my typical morning rituals but it also brings with it much drier air. This dry air can create static problems in your facility that will wreak havoc on your processes and sometimes the operators.

PET bottle
Empty PET dishwashing liquid bottle

I recently had the pleasure of working with a customer in Vietnam that was having some issues with static electricity in a labeling process. The company makes dishwashing liquid and before bottling they must label the PET bottles. They were not able to get the labels to properly adhere to the bottle. This forced them to periodically stop the line and have two operators manually rub the surface of the label to get it to stick properly. They knew there had to be a better way. After spending some time searching the internet for solutions, they stumbled upon the EXAIR website and reached out to us for help.

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Operators fixing the labels on the PET bottles

The solution was to install (2) 112012 12” Gen4 Super Ion Air Knives, one on either side of the bottles. They were installed at about a 45° angle with the airflow pattern against the direction of travel of the bottles. This counter-flow as we call it, maximizes the time in contact that the bottles have with the static eliminating ionized airflow. Mounting them in this manner gives the best possible chance of success in any static eliminating, cleaning, drying, or blowoff application. The airflow is able to reach the bottles much earlier up the line than if it were to be simply blowing perpendicular to the bottles.

Unfortunately in this case the customer was unable to quantify their production gains. But they were able to remove the additional process of manually fixing the labels and could operate continuously without interruption. By eliminating the tedious step of inspecting bottles and fixing the labels, worker morale and job satisfaction was significantly improved.

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A 6″ Gen4 Super Ion Air Knife removing static from labels

If the cold, dry winter climate has you worried about static issues in your facility, give us a call. An Application Engineer will be happy to determine a solution from our wide range of Gen4 Static Eliminators.

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

1″ And 2″ Flat Super Air Nozzles Overview

In most “general” blowoff applications, the conical airflow pattern from a standard round shaped nozzle is ideal when trying to remove dust or light debris from the surface of a part or material. However in certain applications, a focused, laminar flow of air is required to produce the desired result, such as cleaning peanut butter from a fill nozzle or ejecting parts in a stamping operation.

EXAIR manufactures our 1″ Flat and 2″ Flat Super Air Nozzles, which provide a 1″ and 2″ (respectively) wide, forceful stream of high velocity, laminar airflow while consuming only a small amount of compressed air. Both the 1″ and the 2″ are available in Zinc Aluminum alloy, rated up to 250°F (121°C), or 316 Stainless Steel construction, rated up to 1,000°F (538°C)

1″ Flat Super Air Nozzle
2″ Flat Super Air Nozzle

Their unique design incorporates a specially designed, replaceable shim, to maintain a critical gap between the cap and body, resulting in the focused airflow. They are shipped from stock with a .015″ shim installed.

Using the optional shim kit, the shims can be changed out to .005”, .010” or .020”, which allow you to increase or decrease the force and flow by either opening or closing the gap, providing more or less force and flow to meet the demand of the application.

(Here’s a short video showing how easy it is to change out the shims)

We also offer our High Power versions of these nozzles which feature a thicker shim installed (0.025″) for applications requiring higher thrust and velocity.

If you have an application you would like to discuss or to see how the Flat Super Air Nozzles might improve your process, give me a call, I’d be happy to help.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

Two Types of Air Amplifiers – Volume and Pressure

When the topic of Air Amplifiers comes up, there are two avenues to consider –  is it the air pressure or the air volume that you wish to amplify?  There exists technologies to amplify either parameter, and we will examine them both.

There may be equipment or processes within a facility that operate best at air pressures higher than can be delivered, due to air compressor limitations or the supply system. An Air Pressure Amplifier can take the existing compressed air supply, and boost the pressure allowing for the higher needed air pressure without requiring a dedicated compressor capable of operating at the higher pressure.

An Air Pressure Amplifier is basically an air pump, driven by a portion of the compressed air supply.  The pump cycles and compresses the remaining amount of compressed air to a higher outlet pressure. This higher output pressure can be used to operate the equipment or process that required the pressure levels that the base system could not supply. The drawback is that the pump system consumes a good amount of the compressed air volume, to power the pump which reduces the amount of air available for other equipment or processes.  This drives up the compressed air consumption for the system, and requires the extra capacity to operate.

The other type of Air Amplifier is the kind that amplifies the air flow volume. EXAIR manufactures this type of amplifier.

AirAmplifiers

The air flow amplification works by taking compressed air (1) and directing into an annular chamber (2). It is then throttled through a small ring nozzle (3) at high velocity. This primary stream of air adheres to the Coanda profile (4) and is directed through the outlet. A low pressure area is created at the center, inducing a high volume flow (5) of surrounding air to be drawn in and added to the main air stream. The combined flow of primary and surrounding air exits as a high volume, high velocity flow.

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EXAIR manufactures (2) types of Air Amplifiers, the Super Air Amplifier and the Adjustable Air Amplifier.  In addition, a special model for High Temperature applications is available.  Sizes range from 3/4″ (19mm) to 8″ (203mm) to meet most air flow requirements.  Air amplification ratios start at 12:1 for the 3/4″ model and increase to 25:1 for the 4″ and 8″ models.

Charts and tables are available to help determine the right Air Amplifier for the job.

If you have questions about the Air Amplifiers, or would like to talk about 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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Twitter: @EXAIR_BB

More Force is not Always Better for Cleaning Glass

Glass Annealing Machine with model 110230

A float glass company purchased an EXAIR model 110230 Super Air Knife kit to clean the surface of glass sheets.  The production manager watched the video of the performance of the Super Air Knife, and he was amazed at the efficiency, effectiveness, and safety that they could provide.  (We have many EXAIR Product videos here).  After they received the Super Air Knife, they mounted it after the annealing process to remove any specks of dirt and debris prior to the final visual inspection.  They were getting some false rejections from contamination that remained on the sheets, and they believed that they needed more force to better clean the surface of the glass.

The blowing system was operating at 73 PSIG (5 bar) air pressure, the maximum amount that could be supplied at the machine.  With the dynamics of the Super Air Knife, the blowing force could be increased by changing the shim thickness.  The plant manager contacted me about the characteristics in force and flow by changing from the standard 0.002” (0.05mm) thick shim to the 0.003” (0.08mm) or 0.004” (0.1mm) thick shim.  (These shims are Included in the shim set for aluminum Super Air Knife kits along with a 0.001” (0.025mm) thick shim).  As an Application Engineer at EXAIR, I was inquisitive about the application and wanted to do a “forensic” analysis of the system to generate the best suggestion.  So, I had him send me pictures of their setup.

With non-conductive materials like glass and plastic, static can be a huge issue.  Static forces can easily be generated and will cause dirt and debris to “stick” to a surface.  This attraction is very strong and will make it very difficult to remove.  If the static force can be neutralized, then the contamination can easily be removed from a non-conductive surface.

With this understanding, my initial suggestion for the company above was to remove the static charges from the surface of the glass with an EXAIR Static Eliminator.  With the complimentary design of the Super Air Knife, it is simple to mount an Ionizing Bar directly to the Super Air Knife that they currently installed.  I recommended a model 8030, 30” (762mm) long Gen4 Ionizing Bar, and a model 7960 Power Supply to transform the Super Air Knife into a Gen4 Super Ion Air Knife.  The positive and negative ions that are generated by the Gen4 Ionizing Bar can be carried by the laminar air flow of the Super Air Knife to treat the surface.  This combination can work well to remove static charges up to 20 feet (6m) away.  Once the static is removed, the force of the air stream would easily remove any dust or debris from the glass surface.

Gen4 Super Ion Air Knife

As an added note from the picture above, I recommended a different position for the Super Air Knife, or soon to be Gen4 Super Ion Air Knife to optimize the blowing area.  The glass company had the air knife positioned to blow straight across the surface of the glass.  For proper cleaning and better contact time, I suggested to mount the Super Air Knife with the Ionizing Bar about 6” (152mm) above the surface of the glass and angle it to about 45 degrees.  This would increase the contact angle and allow for a better blowing force to remove all the debris.  By adding the Gen4 Ionizing Bar and adjusting the blowing angle, they were able to reduce the air pressure from 73 PISG (5 bar) to 30 PSIG (2 bar); saving compressed air and reducing false rejections.

Pictures are always helpful in analyzing an application.  With the company above, we were able to optimize their cleaning process and reduce the total amount of compressed air required.  If you find that you need more force to clean a non-conductive surface, EXAIR Static Eliminators will resolve these static problems.  If you would like to discuss your application with an Application Engineer at EXAIR, we can go through the “forensics” analysis for optimization.

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

Absolute Pressure Ratio

This model 1101 Super Air Nozzle requires 14 SCFM @ 80 PSIG. How much air will it consume at 60 PSIG?

Compressed air driven devices are always given a specification for the compressed air flow at a certain pressure.  For example, an EXAIR model 1101 Super Air Nozzle has a specified flow of 14 SCFM at 80 PSIG.  This means that when this nozzle is operated at 80 PSIG, it will require 14 SCFM of compressed air flow.  But what if the force from the nozzle is too high when operated at 80 PSIG and a lower operating pressure is needed?

Thankfully, we can calculate the compressed air flow at a different pressure using the absolute pressure ratio.  The absolute pressure ratio says that for any given change in absolute operating pressure, there will be a proportional change in the air consumption of a device.  So, what is an absolute pressure?

Put simply, an absolute pressure is the value which you would measure on pressure gauge plus the atmospheric pressure (PSIA, or Pounds per Square Inch Atmospheric).  So, our 80 PSIG operating pressure mentioned above is an absolute pressure of 94.5 PSI (80PSIG + 14.5 PSIA).  Similarly, if we wanted to determine the compressed air flow at an operating pressure of 60 PSIG, our absolute pressure would be 74.5 PSI (60 PSIG + 14.5 PSIA).

The absolute pressure ratio is a ratio of the new absolute operating pressure (new PSIG + PSIA) compared to the known absolute operating pressure (known PSIG + PSIA).  For example, when comparing an operating pressure of 60 PSIG to an operating pressure of 80 PSIG, we will end up with the following ratio:

This means that our absolute pressure ratio in this case is 0.7884.  To determine the compressed air flow for the model 1101 Super Air Nozzle at 60 PSIG, we will take this ratio value and multiply it by the known flow value at 80 PSIG.  This will yield the following:

Utilizing this formula allows us to truly compare a compressed air powered device at different operating pressures.  If we did not use the absolute pressures when comparing compressed air devices at differing pressures, our values would be erroneously low, which could yield to improper compressed air system planning and performance.  And, using the absolute pressure ratio allows anyone to make a true comparison of compressed air device performance.  If specifications are given at different pressures, performance data can be misleading.  But, by using the absolute pressure ratio we can make a more exact evaluation of device operation.

If you have a question about your compressed air device and/or how a change in pressure will impact compressed air flow, contact our Application Engineers.  We’ll be happy to help.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

No Drip Atomizing Spray Nozzles Improve Pizza Crusts

I like some better than others, but I don’t believe I’ve ever had bad pizza. That’s why I was pretty excited when I got to talk to a caller from a popular pre-packaged pizza crust maker. When these crusts leave their oven, they spray a coating of seasoned oil on them. This not only flavors, but preserves the quality from the time they make & package them to the time I celebrate life with a tasty slice, right out of my oven.

They were using inexpensive liquid-only nozzles that led to an inconsistent application of the oil…sometimes too much; other times, too little. And, it was always spraying, even in between the individual crusts as they came down the conveyor, leading to wasted oil that had to be cleaned up later.

They were already familiar with our Super Air Nozzles, as they had several Model HP1125SS 2″ High Power Flat Super Air Nozzles in use for blowing off the packages prior to labeling, so the caller asked if we might have a solution for the oil too.

We did.

After considering the size of the crust and the distance at which they needed to install the nozzle, they decided to try a Model AF2010SS Internal Mix Flat Fan Pattern No-Drip Atomizing Spray Nozzle. This applies a consistent and even coating of oil, and, by feeding a signal from the oven controls into a solenoid valve in the compressed air supply line, they’ve eliminated the excess spray, leading to savings in material cost and cleanup time.

EXAIR No Drip Atomizing Spray Nozzles…controllable, fine mist on demand, with no mess.

If you’d like to know more about how EXAIR Atomizing Spray Nozzles can save you time, mess, and liquid, give me a call.

Russ Bowman
Application Engineer
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Intelligent Compressed Air: What is an Air Compressor?

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Example of the supply side of a compressed air system

One thing that is found in virtually every industrial environment is an air compressor. Some uses for the compressed air generated are: powering pneumatic tools, packaging, automation equipment, conveyors, controls systems, and various others. Pneumatic tools are favored because they tend to be smaller and more lightweight than electric tools, offer infinitely variable speed and torque, and can be safer than the hazards associated with electrical devices. In order to power these devices, compressed air must be generated.

types of compressors

There are two main categories of air compressors: positive-displacement and dynamic. In a positive-displacement type, a given quantity of air is trapped in a compression chamber. The volume of which it occupies is mechanically reduced (squished), causing a corresponding rise in pressure. In a dynamic compressor, velocity energy is imparted to continuously flowing air by a means of impellers rotating at a very high speed. The velocity energy is then converted into pressure energy.

Of the positive-displacement variety they are broken down further into two more categories: reciprocating and rotary. A reciprocating compressor works like a bicycle pump. A piston reduces the volume occupied by the air or gas, compressing it into a higher pressure. There are two types of reciprocating compressors, single or double-acting. Single-acting compressors are the most common and are available up to 30HP at 200 psig. Their small size and weight allow them to be installed near the point of use and avoid lengthy piping runs. These are the types of compressors that would be commonly found in your garage. The double-acting reciprocating compressor is much like its single-acting brethren, only it uses both sides of the piston and cylinder for air compression. This doubles the capacity of the compressor for a given cylinder size. They are much more efficient than single-acting compressors, but are more expensive and do require a more specialized installation and maintenance.

Rotary compressors are available in lubricant-injected or lubicrant-free varieties. These types of compressors use two inter-meshing rotors that have an inlet port at one end and a discharge port at the other. Air flows through the inlet port and is trapped between the lobes and the stator. As the rotation continues, the point intermeshing begins to move along the length of the rotors. This reduces the space that is occupied by the air, resulting in an increase in pressure. In the lubricant-injected compressors, the compression chamber is lubricated between the intermeshing rotors and bearings. This takes away the heat of compression and also acts as a seal. In the lubricant-free varieties, the intermeshing rotors have very tight tolerances and are not allowed to touch. Since there is no fluid to remove the heat of compression, they typically have two stages of compression with an intercooler between and an after cooler after the second stage. Lubricant-free compressors are beneficial as they supply clean, oil-free compressed air. They are, however, more expensive and less efficient to operate than the lubricant-injected variety.

On the other side of the coin, we have the dynamic compressors. These are comprised of two main categories: axial and centrifugal. These types of compressors raise the pressure of air or gas by imparting velocity energy and converting it to pressure energy. In a centrifugal air compressor, air continuously flows and is accelerated by an impeller. This impeller can rotate at speeds that exceed 50,000 rpm. Centrifugal air compressors are generally much larger and can accommodate flow ranges of 500-100,000 CFM. They also provide lubricant-free air.

Axial compressors are used for situations that require lower pressure but high flow rates. They do not change the direction of the gas, it enters and exits the compressor in an axial direction. It is accelerated and then diffused which creates the increase in pressure. A common application that would be served by this type of compressor is to compress the air intake of gas turbines. They have a relatively high peak efficiency, however their large overall size and weight as well as the high starting power requirements pose some disadvantages.

Just as you can find a wide variety of makes and models of automobiles, the same can be said for air compressors. The size, type, and features will be dictated by the types of applications that you’ll be needing the compressed air for in your facility. A quick chat with your local air compressor supplier will help you to determine which type is most suitable for you.

Of course, any of these types of compressors can be used to supply air to your engineered Intelligent Compressed Air Products. If you have an application in your facility that could benefit from an engineered solution, give us a call. An Application Engineer would be happy to discuss your options with you and see to it that you’re getting the most out of your compressed air!

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

 

Images Courtesy of  the Compressed Air Challenge and thomasjackson1345 Creative Commons.