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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.
- 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.
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.
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.
Preventative maintenance for compressed air demand products is a simple as keeping the compressed air clean and condensate free. It is simple because all it takes is a filter and keeping the filter element clean, just like you do for your home furnace and/or air conditioner.
I received a phone call from a customer that needed replacement elements for EXAIR filters. They were using four different models of Filter Separators and Oil Removal Filters. The filters had been in service for one year, and the internal elements needed to be changed. They requested a quote to replenish the replacement elements that they stocked as a preventative measurement. What an idea!
Majority of EXAIR products use compressed air for cleaning, cooling, conveying, static elimination, coating and more. To help keep your EXAIR products running efficiently, it is important to supply them with clean, dry, pressurized air. EXAIR offers a line of Filter Separators and Oil Removal Filters to supply quality air to your equipment. In this blog, I will explain the two types of filters that we carry and the maintenance requirements. The filters and preventative measures can play an important part in your compressed air system.
Filter Separators are used to remove bulk liquid and contamination from the compressed air stream. They utilize a 5-micron filter with a mechanical separation to help remove large amounts of dirt and water. This type of filter would be considered the minimum requirement for filtration. Most of the Filter Separators come with an auto-drain to automatically dispense the collection of oil and water. EXAIR offers a variety of port sizes and flow ranges to meet your pneumatic flow requirement. For maintenance, the filter elements should be changed once a year or when the pressure drop reaches 10 PSID, whichever comes first. I created a list in Table 1 showing the correct replacement element kits for each model number. And for any reason, if the bowl or internal components get damaged, we also have Rebuild Kits as well. Just remember, the air quality is very important for longevity and functionality for pneumatic products and even for EXAIR products.
The Oil Removal Filters can make your compressed air even cleaner. They work great at removing very small particles of dirt and oil. They are made from glass fibers and can remove particles down to 0.01 micron. They are designed to collect small particles and to coalesce the liquid particles into a large droplet for gravity to remove. Because of the fine matrix, Oil Removal Filters are not great for bulk separation. If you have a system with lots of oil and water, I would recommend to use the Filter Separator upstream of the Oil Removal Filter. As with the Filter Separator, the filter element should be changed once a year or at a pressure drop of 10 PSID. EXAIR also offers a variety of port sizes and flow ranges. Table 1 below shows the replacement Element Kits as well as the Rebuild Kits. If the application requires very clean compressed air, the Oil Removal Filter should be used.
By using EXAIR filters, they will clean your compressed air to prevent cross contamination, performance issues, and premature failures. As an ounce of prevention, you can add the replacement elements in stock and enter them in your preventative maintenance program. With clean quality air, your pneumatic system and EXAIR products will provide you with effective, long-lasting performance without maintenance downtime. If you would like to discuss the correct type of filters to use in your application, you can speak with an Application Engineer. We will be happy to help you.
Air entrainment is a term that we bring up quite often here at EXAIR. It’s this concept that allows many of our products to dramatically reduce compressed air consumption. The energy costs associated with producing compressed air make it an expensive utility for manufacturers. Utilizing engineered compressed air products that will entrain ambient air from the environment allow you to reduce the compressed air consumption without sacrificing force or flow.
Products such as the Super Air Knife, Super Air Nozzle, Air Amplifier, and Super Air Wipe all take advantage of “free” air that is entrained into the primary supplied airstream. This air entrainment occurs due to what is known as the Coanda effect. Named after renowned Romanian physicist, Henri Coanda, the Coanda effect is used in the design of airplane wings to produce lift. As air comes across the convex surface on the top, it slows down creating a higher pressure on the underside of the wing. This creates lift and is what allows an airplane to fly.
This is also the same principle which is allowing us to entrain ambient air. As the compressed air is ejected through a small orifice, a low-pressure area is created that draws in additional air. Our products are engineered to maximize this entrained air, creating greater force and flow without additional compressed air. Super Air Amplifiers and Super Air Nozzles are capable of up to a 25:1 air entrainment ratio, with just 1 part being the supplied air and up to 25 times entrained air for free!! The greatest air entrainment is achieved with the Super Air Knife at an incredible ratio of 40:1!
This air entrainment principle allows you to utilize any of these products efficiently for a wide variety of cooling, drying, cleaning, or general blowoff applications. In addition to reducing your compressed air consumption, replacing inefficient devices with engineered products will also dramatically lower your sound level in the plant. Sound level in some applications can even be reduced down to a point that would eliminate the need for hearing protection with the OSHA maximum allowable exposure limits set at 90 dBA for an 8-hour shift.
If you have inefficient blowoff devices in your facility, give us a call. An Application Engineer will be happy to help you select a product that will “quietly” reduce your compressed air consumption!
- It’s “plug and play,” all the way. Connect the cable to the Power Supply, and hook it up to your compressed air system, and you’re ready to go.
- It’s efficient and quiet. The high velocity jet entrains an enormous amount of air from the surrounding environment, where it’s ionized and ready to eliminate static charge quickly and effectively.
- Instant static dissipation, at your fingertips (literally) – squeeze the trigger to blow ionized air, anywhere you want (well, within the reach of the 10 foot cable, anyway.)
Again, the Gen4 Ion Air Gun is just one of our Static Eliminator products. How do you know if it’s the right one? The selection of many EXAIR Intelligent Compressed Air Products comes down to the size & shape of the air flow that will solve the application. Static Eliminators are no different.
- If you need to treat a large surface, you might be looking for a Gen4 Super Ion Air Knife. They come in lengths from 3 inches to 9 feet long, and blow a laminar, even curtain of ionized air that’s extremely effective and fast at static elimination, even at very low supply pressures.
- Gen4 Super Ion Air Wipes blow a 360° ionized airstream for pipes, cables, extruded shapes, etc.
- Gen4 Ion Air Cannons and Gen4 Ion Air Jets are made to mount in place, and blow a focused, conical flow of ionized air.
If you’ve got large areas, multiple surfaces, or complex geometries to contend with, one (or an array) of these products might be the solution. For a simple, straightforward, hand held static elimination solution, though, it just doesn’t get any easier than the EXAIR Gen4 Ion Air Gun. Call me to find out how you can get one today.
***Order any qualifying EXAIR Static Eliminator by February 28, 2019, and we will include a FREE AC Sensor. Click here for details.***
I was recently working with a process Engineer at a food packaging plant on installing a Super Air Knife to blow excess water off a food product. This product was moving single file on a conveyor belt with about 6 feet between each product. The belt was moving pretty slow so we wanted to turn the air knife on only when the product was in front of the knife, which saves compressed air and energy. To do this we used the ELECTRONIC FLOW CONTROL (EFC). If the knife ran the entire time it would be wasting any air blowing during one of the 6′ long gaps. This would also put an unnecessary strain on their already taxed compressed air system. The EFC let him only supply air to the Knife when it saw a product on the belt. To read more about the EFC click here!
This application worked perfectly, but they had one other issue. Throughout the day it seemed as if they were losing compressed air pressure at the knife. What they found was during peak compressed air usage in the plant the compressor couldn’t keep up with the demand. Fear not, the Super Air Knife was only running for 7 seconds and was off for 20 seconds. This was a perfect application for EXAIR’s Receiver Tank.
Receiver Tanks are great for applications that require an intermittent demand for a volume of compressed air. This can cause fluctuations in pressure and volume throughout the compressed air system with some points being “starved” for compressed air. EXAIR’s Model 9500-60 60 Gallon Receiver Tank can be installed near the point of high demand so there is an additional supply of compressed air available for a short duration. The time between the high volume demand occurrences should be long enough so the compressor has enough time to replenish the receiver tank.
If you have a process that is intermittent, and the times for and between blow-off, drying, or cooling allows, a Receiver Tank can be used to allow you to get the most of your available compressed air system. If you need any assistance calculating the need for a receiver, please let us help.
Note – Lee Evans wrote an easy to follow blog that details the principle and calculations of Receiver Tanks, and it is worth your time to read here.
If you 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.
Since EXAIR manufactures and distributes our own products, we have the flexibility to provide custom products, special processing, unique packaging and more. If your process or specifications are something special, let us know and we will do our best to accommodate any special considerations you might need. Following is one example for a customer who purchases air guns.
Several months ago I received a call from a company that was looking for a specialized air gun. This company was involved in the servicing of highly specialized measuring equipment and needed a safe, quiet, & efficient air gun that also had to be completely oil/contamination free. This was to ensure no contamination would result from using the air gun on any of their equipment. Ultimately this meant that every air gun component needed to be washed, rinsed and dried to ensure there was no residual oils or dirt from manufacturing left on or in any component of the gun.
Our customer decided on the highly versatile Vari-Blast Compact Safety Air Gun with the award-winning Nano Super Air Nozzle, specifically models 1698SS and the 1698SS-6. EXAIR presented a written process to the customer. This process explained how we would identify and manufacture their specific air gun in order to assure the customer that would receive a consistently clean air gun, every time.
Additionally the customer had specifications requiring special packaging as they were going to ship these globally to their service team members. To ensure safe arrival no matter where they are shipped, EXAIR provides special handling and packaging which exceeds their requirements.
Also, when you are looking for expert advice on safe, quiet and efficient point of use compressed air products give us a call. We would enjoy hearing from you!
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.
From the main page, hover the mouse pointer over ‘KNOWLEDGE BASE‘ and the pop-up menu will appear as seen below. Select ‘APPLICATIONS’
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.
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.
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.