Many Air Knife Materials and Shim Options to Suit Your Application

The EXAIR Super Air Knives are used in many applications ranging from part drying, to web cleaning, to conveyor blowoff, and many other uses. For most processes, the aluminum models provide the performance required and withstand the environmental conditions present.

Ambient temperature limits for the aluminum models is 180°F (82°C). EXAIR also offers the air knives in types 303 and 316 Stainless Steel, which increase the temperature limit to 800°F (427°C) and provides a great degree of corrosion resistance. For the harshest, most corrosive environments, an air knife constructed of Polyvinylidene Fluoride (PVDF) with a temperature limit to 275°F (135°C) is available.

Super Air Knives
Aluminum, Stainless Steel and PVDF Super Air Knives

But what can we do about those applications where the increased corrosion resistance isn’t needed and the temperatures do not approach anywhere near to 800°F (427°C)?

The solution to this situation is an aluminum air knife with a custom stainless steel shim. The aluminum material is rated to 400°F (204°C) and the shim is good to 800°F (427°C) so this knife can be used in those hotter environments up to 400°F (204°C). This option helps to keep the cost of the knife low, by utilizing the lower cost aluminum for the body and cap.

The table below details the materials of construction options for the Super Air Knife – a wide array of material offerings to suit even the hottest, harshest conditions.

Air Knife Temperature Table

We recommend consulting with an Application Engineer to review the application, process, and environmental conditions, and we can present best options.

And don’t forget, the shims can be further customized for special blowoff requirements. See the blog that my colleague, Russ Bowman, posted here.

If you have questions about Super Air Knives or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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What is Sound and Interesting Facts About Sound

In physics, sound is a wave of pressure. It occurs in a medium, which can be a solid, liquid or gas. Sound cannot travel through a vacuum, such as in space. The wave of pressure reaches our ears and causes the ear drum to vibrate, which then goes through a complex process to ultimately be perceived as audible sound.

There are several characteristics of sound waves that can be measured and help define the sound. A sound wave can be visualized as a repeating sinusoidal wave (see below), and can be described by these properties – frequency and wavelength, amplitude, and speed.

Sound Wave
Sound Wave
  • Frequency is the number of cycles in 1 second, and is measured in Hertz (Hz)
  • Wavelength is the distance over which 1 cycle occurs, and for audible sound is  between 17 m and 17 mm long
  • Amplitude is the measure of its change over a single period, and normally a measure of sound loudness
  • Speed is the distance traveled per unit time

The speed of sound in air can be found using the equation:  a = Sqrt (γ•R•T)

where for air:
γ = ratio of specific heats = 1.4,
R = gas constant = 286 m²/s²/K
T = absolute temperature in °K (273.15 + °C)

At room temperature, 22°C (71.6°F), the speed of sound is 343.8 m/s (760 mph)

Some interesting facts about sound:

  • Sounds generally travels faster in solids and liquids than in gases.
  • You can estimate the distance from a lightning strike by counting the seconds that pass between seeing the lightning flash and hearing the thunder.  Take this duration an divide by 5 to get the distance away, in miles.
  • Humans normally hear sound frequencies between 20 Hz and 20,000 Hz.
  • Sound waves above 20,000 Hz are known as ultrasound, and sound waves below 20 Hz are known as infrasound.
  • Sound travel through water close to 4 times faster then through air.
  • The sound of a cracking whip occurs because the speed of the tip has exceeded the speed of sound.

Sound that is too loud can be a problem. The Occupational Safety and Health Administration (OSHA) has set limits on the noise exposure that an employee can be subjected. Exceeding these values can cause permanent damage to your ears and cause noise induced hearing loss. So, knowing and reducing the sound levels within a manufacturing operation is important.

OSHA Chart

EXAIR has many products that can help reduce the sound levels in your processes.  With products such Air Knives, Air Wipes, Air Amplifiers, Air Nozzles and Jets, and Safety Air Guns, strong, quiet and efficient blowoff, drying, and cooling can be performed.

Quiet Products

If you have questions about sound and keeping your sound levels in check or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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Compressed Air Use in the Aerospace Industry

EXAIR’s products have been used for a very large selection of applications in almost every industry.  Today I want to highlight a few that pertain to the Aerospace Industry.

First – a quick lesson on how to access the Applications database– Be sure to Register and then Log In

From the main page, hover the mouse pointer over ‘KNOWLEDGE BASE‘ and the pop-up menu will appear as seen below.  Select ‘APPLICATIONS’ Website Applications.png

On the left hand side of the screen you will see a gray navigation pane that shows Application with a list underneath.  Scroll down the main page and you will see a second heading in the navigation pane labeled “Industry”.  You can select your industry from the list provided.  For today’s example we will select Aerospace.

Industry_App_Database
The Industry section of the Application Database is found on the left hand side of the screen in the navigation pane.

Once the industry is selected there will be a new list of applications that are displayed in the center of the page.   Simply select the application you would like more information on and the details will display.

Below, we showcase the application from a machine manufacturer for the Aerospace industry.   This customer manufactured the production equipment of a flexible, porous material that is continuously passed through a wash tank prior to cutting to length.  They were interested in speeding the drying process of this strand, and considered blowing hot air onto it.  It was not feasible to install an electrically powered hot air blower or gun.  They needed an air flow of approximately 15 SCFM at 200°F, and had 70 psig air supply with a large volume available.  They utilized a Vortex Tube installed over the strand after it exited the dip tank.   The Vortex Tube was oriented with the hot air exhaust blowing on to the strand to dry the strand.  The customer stated that they not only met their expectations but exceeded the original hopes and were able to dry the product quicker and safer than expected.

Vortex_Tube_Drying_Material
Selecting any of the listed applications in the center of the screen will display the details of that particular application.

This is just one of many applications that are showcased in the Application Database for the Aerospace industry.   Those are just a small sampling of the thousands of applications that can be researched through the database.  If you would like to share your application to the database, feel free to contact an Application Engineer.

If you have questions about any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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Custom Air Amplifiers for Special Applications from EXAIR

The EXAIR Super Air Amplifiers and Adjustable Air Amplifiers are used in 100’s if not 1000’s of applications and locations across the world.  For cooling, drying, and cleaning of parts as well as venting and exhausting of smokes and fumes, or dust collection – the Air Amplifiers are sure to get the job done.

The Super Air Amplifiers are made of aluminum and are sized from 3/4″ to 8″ to cover a wide range of applications. Compact and lightweight, no electricity, no moving parts, and instant on/off are just a few of the features.

The Adjustable Air Amplifiers are made of aluminum or type 303 stainless steel and are sized from 3/4″ to 4″, and with adjustable output, provide a wide spectrum of performance.  They have the same great features of the Super Air Amplifier with the added benefit of varying force and flow.

2″ Super Air Amplifier and 2″ Stainless Steel Adjustable Air Amplifier

Even with the wide variety of types, sizes, and materials of construction, a customer may have a special need and there are numerous ways that EXAIR can customize the Air Amplifiers.  I’ll touch on several from the basics to the most complex.

  • The Super Air Amplifiers come with a stock shim that sets the performance seen in the catalog. There are other shim thicknesses available if more or less flow is preferred, and they can be installed at the factory if desired.
  • The Adjustable Air Amplifiers are designed for varying output by turning the plug further in to or out of the body. If there is a performance setting that is preferred, we can test, adjust and set it to meet that performance, allowing to be installed and ready for optimum results.
  • If the use of a special material will increase the benefit of the Air Amplifier, we can explore several options with you. One customer needed an Adjustable Air Amplifier with a PTFE plug to help draw a sticky material through a process and prevent the material from adhering to the surface of the Air Amplifier.
  • For those applications where the Air Amplifier is to be installed into a piping system, custom design with flanged ends can be done. Recent designs include stainless steel Adjustable Air Amplifiers with class 150 raised face flanges, and another with sanitary Tri-Clamp style.

Adjustable Air Amplifier with PTFE Plug, Class 150 Raised Face and Sanitary Tri-Clamp Flanges

  • A special High Temperature version was developed for moving hot air to surfaces requiring uniform heating while in a furnace or oven. This special design is rated for environments up to 700°F and its surface is protected from heat stress by a mil-spec coating process.  This special High Temperature Air Air Amplifier was so popular, it became a standard offering and is in stock!

high temp air amplifier1-1/4″ High Temperature Air Amplifier

For over 35 years, EXAIR has been designing and manufacturing the best performing and highest quality products in the marketplace. If you have a special requirement and in need of a custom solution, we’ve got the experience and history to solve most problems.

If you have questions about Air Amplifiers, custom Air Amplifiers, or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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The Wonders of The Gen4 Super Ion Air Knife

The Gen4 Super Ion Air Knife is a powerful static eliminator that prevents jamming, tearing, shocks and dust build up by neutralizing static and blowing away the debris.

The Gen4 Super Ion Air Knife combines the quiet and efficient Super Air Knife with the compact design of the rugged Gen4 Ionizing Bar resulting in a total solution to remove static electricity from plastics, webs, sheet stock and other product surfaces. Removing the static helps reduce or eliminate the process issues that the static electric causes, allowing for greater production speeds, improved product quality and a cleaner product.

The Gen4 Super Ion Air Knife floods an area or surface with static eliminating ions. With a uniform airflow across its length, misalignment to critical surfaces like webs is avoided.  The force can be adjusted from a light breeze, to a full out blast of air. The Gen4 Super Ion Air Knife is electrically powered, is shockless and has no moving parts.

How It Works

gen4siak_hwrks_800x
How The Gen4 Super Ion Air Knife Works

In the diagram above, compressed air flows through an inlet (1) into the plenum chamber of the Gen4 Super Ion Air Knife. The flow is directed to a precise, slotted orifice. As the primary airflow exits, it creates a uniform sheet of air across the entire length, pulling in in surrounding air (2). An electrically powered Gen4 Ionizing Bar (3) fills the curtain of air with positive and negative charges. The air stream delivers the static eliminating ions to the product surface (4) where it instantly neutralizes static and cleans off dust and other particulates.

The Gen4 Super Ion Air Knives are powerful tools, and very quickly dissipates 5kV of static even at low compressed air supply pressures. At 5 PSIG, only 3.7 SCFM (0.3 BAR, only 105 SLPM) of compressed air per foot of length is required!!  Sound levels are also very low, resulting in quiet operation.

super ion air knife performance

Added Features –

  • Compressed Air Inlets are provided on each end and the bottom of the Super Air Knife
  • Thicker shims can be installed easily if a harder air flow is needed
  • Emitter points are sharp, durable stainless steel
  • The high voltage cable is armored to resist cuts and abrasion, and has integral grounding.  Threaded bayonet connector is fully assembled and ready to use
  • Electromagnetically shield cable protects sensitive electronics
  • Gen4 Ionizing Bars and Power Supplies are UL Component Recognized to U.S and Canadian safety standards and are CE and RoHS compliant
  • Power Supplies are 115/230 VAC selectable and come with 2 or 4 outlets
  • Standard lengths from 3″ to 108″ (76mm to 2743mm) are offered, and custom lengths are available to meet your process needs

Successful applications include web cleaning, pre-paint dust removal, shrink wrapper machinery, printing equipment, package cleaning,and bag opening/filling operations.

If you have questions about Gen4 Super Ion Air Knives, other types of Static Elimination products,  or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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Starting a Leak Prevention Program

Since all compressed air systems will have some amount of leakage, it is a good idea to set up a Leak Prevention Program.  Keeping the leakage losses to a minimum will save on compressed air generation costs,and reduce compressor operation time which can extend its life and lower maintenance costs.

SBMart_pipe_800x

There are generally two types of leak prevention programs:

  • Leak Tag type programs
  • Seek-and-Repair type programs

Of the two types, the easiest would be the Seek-and-Repair method.  It involves finding leaks and then repairing them immediately. For the Leak Tag method, a leak is identified, tagged, and then logged for repair at the next opportune time.  Instead of a log system, the tag may be a two part tag.  The leak is tagged and one part of the tag stays with the leak, and the other is removed and brought to the maintenance department. This part of the tag has space for information such as the location, size, and description of the leak.

The best approach will depend on factors such as company size and resources, type of business, and the culture and best practices already in place. It is common to utilize both types where each is most appropriate.

A successful Leak Prevention Program consists of several important components:

  • Baseline compressed air usage – knowing the initial compressed air usage will allow for comparison after the program has been followed for measured improvement.
  • Establishment of initial leak loss – See this blog for more details.
  • Determine the cost of air leaks – One of the most important components of the program. The cost of leaks can be used to track the savings as well as promote the importance of the program. Also a tool to obtain the needed resources to perform the program.
  • Identify the leaks – Leaks can be found using many methods.  Most common is the use of an Ultrasonic Leak Detector, like the EXAIR Model 9061.  See this blog for more details. An inexpensive handheld meter will locate a leak and indicate the size of the leak.

    ULD_Pr
    Using the Model 9061 Ultrasonic Leak Detector to search for leaks in a piping system
  • Document the leaks – Note the location and type, its size, and estimated cost. Leak tags can be used, but a master leak list is best.  Under Seek-and-Repair type, leaks should still be noted in order to track the number and effectiveness of the program.
  • Prioritize and plan the repairs – Typically fix the biggest leaks first, unless operations prevent access to these leaks until a suitable time.
  • Document the repairs – By putting a cost with each leak and keeping track of the total savings, it is possible to provide proof of the program effectiveness and garner additional support for keeping the program going. Also, it is possible to find trends and recurring problems that will need a more permanent solution.
  • Compare and publish results – Comparing the original baseline to the current system results will provide a measure of the effectiveness of the program and the calculate a cost savings. The results are to be shared with management to validate the program and ensure the program will continue.
  • Repeat As Needed – If the results are not satisfactory, perform the process again. Also, new leaks can develop, so a periodic review should be performed to achieve and maintain maximum system efficiency.

In summary – an effective compressed air system leak prevention and repair program is critical in sustaining the efficiency, reliability, and cost effectiveness of an compressed air system.

If you have questions about a Leak Prevention Program or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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Choosing the Right Vortex Tube – Max Refrigeration vs. Max Cold Temperature

The Vortex Tube is a low cost, reliable, maintenance free way to provide cooling to a wide variety of industrial spot cooling problems.

VT_air2

There are two (2) popular uses for the Vortex Tubes.  One is to spot cool a warm item as fast as possible.  The other is to chill an item to as low a temperature as possible. Because these are very different requirements, different Vortex Tube configurations exist to handle each.

For those applications of spot cooling, we recommend the 3200 series of Vortex Tubes. They are designed to be most efficient at providing maximum refrigeration, which is a function of high cold air flow rate and moderate temperature differential of the cold air to the warm item.

And for those applications of chilling an item to a very low temperature at low flow rate , we recommend the 3400 series of Vortex Tubes.  They are designed to be most efficient at providing maximum cold air temperatures, but with a lower cold air flow rate.

An important parameter for the Vortex Tubes is the Cold Fraction.  By adjusting the hot valve on a vortex tube, the amount of air that is discharged through the cold end changes. When expressed as a percentage of the total compressed air that is supplied to the vortex tube, we get the Cold Fraction.  For example, if the hot valve is adjusted so that for every 10 parts of compressed air supplied, we get 7 parts of cold air, then we have a 70% Cold Fraction. When you know the Cold fraction setting and the compressed air supply pressure, you can use the Vortex Tube Performance tables and get the cold air discharge temperature.

Using the table below left, at 100 PSIG compressed air pressure and a 70% Cold Fraction, we can expect the cold air discharge temperature drop to be 71°F.  With 70 ° compressed air temperature, the cold air will be at -1°F.

Vortex Tube Charts
Vortex Tube Performance Tables

The 3200 series of Vortex Tubes are for use in the 50-80% Cold Fraction range, and the model 3400 series is designed for use in the 20-50% Cold Fraction ranges, to maximize the performance of each.

In summary, the selection of the Vortex Tube that best meets the application needs is based on the desired cold air flow rate, and the temperature of air desired. Once these are known, using the tables can provide the information needed to select the best option.

For those applications where we are unsure what will work best, we offer the EXAIR Cooling Kits, that include a Vortex Tube (small, medium, or large) and an array of Generators, to allow the configuration of the full range of Vortex Tubes within each size family.

  • Model 3908 – Small Vortex Tube Cooling Kit – build models 3202, 3204, 3208, and 3402, 3404, 3408
  • Model 3930 – Medium Vortex Tube Cooling Kit – build models 3210, 3215, 3225, 3230, 3240, and 3410, 3415, 3425, 3430, 3440
  • Model 3998 – Large Vortex Tube Cooling Kit – build models 3250, 3275, 3298, 3299, and models 3450, 3475, 3498, 3499

3930

If you have questions about Vortex Tubes or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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