You may have heard us speak about contact time. I would like to cover what that means in this blog. Contact time refers to the amount of time that a target part is in the high-velocity airstream produced by an EXAIR blowing product. The longer the contact time, the more effective the blow-off or cooling effect. Optimizing the mounting position of the EXAIR solution relative to the target makes a huge difference in effectiveness. When our customers typically purchase EXAIR products, they have a tendency to improperly install them, reducing their performance capabilities. Let’s look at a Super Air Knife. In the photo above, you can see the relationship between a perpendicular and a recommended setup angle. I have some recommendations that can help to increase the contact time and improve the performance.
Super Air Knife Chamfer
Angle – EXAIR machines a chamfer on the cap of the Super Air Knife as a starting point. You want to have the chamfer parallel with the target line of movement. This will create an air flow angle of about 45 degrees relative to the target. This angle will increase the contact area and contact time, which is very beneficial for removing debris and/or heat. Depending on the speed and height of the target, this can be altered for further refinement.
Distance – For optimum performance, the Air Knife should be between 3″ (76 mm) to 12″ (305 mm) from the target. If you are too close, the amplification ratio is sacrificed, and the force is reduced. If you are too far, the air pattern will start to change, causing the velocity and force to decrease.
Counter-Flow – The direction of the air flow should be blowing in the direction opposite the target movement. As an example, if the parts are moving from left to right, you want the Air Knife to blow from right to left. This will allow the contamination to be blown back away from the cleaned surfaces, and it will increase the impact force to remove contamination, i.e. a head-on collision vs. a rear-end collision.
With these few simple steps, you will begin to maximize the performance and effectiveness of your EXAIR blowing solution. Some accessories can help with the setup, like Swivel Fittings and Stay Set Hoses for the nozzles and the Universal Mounting Kit for the Air Knives. You can modify the impact angle to best suit complex parts and systems. If you need any help to get the most out of our products, you can contact an Application Engineer at EXAIR. We will be happy to hear from you.
John Ball Application Engineer Email: johnball@exair.com Twitter: @EXAIR_jb
I was once on a local theater’s website, ordering tickets to an upcoming show that my wife and I were excited to see. I had the option to pay online and have a digital code emailed to me in lieu of a real live paper ticket. Can you believe they wanted to charge me almost $2 A TICKET for that?!? I adamantly refused (by that I mean I clicked the mouse extra hard on the “Will Call” button before completing my payment)…and saved that $4 (almost) for something REALLY important.
The night of the show, there was a 20-minute line at the Will Call window. Folks who had opted for the digital code were doing a quick scan with their smartphones and walking straight into the theater. I used the $4 I saved to partially pay for a $10 glass of wine from a concession kiosk in the lobby, as a peace offering for my lovely bride. That was indeed “something REALLY important.”
Another time, I was ordering a sump pump backup system for our house. I had the option of paying extra for the deluxe system, which came with all the fittings and a special tool to make installation a bit easier. Even though the ‘deluxe’ system adder was probably a bit more than the cost of the fittings from my local hardware store, I paid the “convenience fee” and got the deluxe system anyway. For the record, during the installation, I realized I would have bought an incorrect fitting at the local store which would have forced an emergency trip while I had the water turned off in my whole house. THAT was an inconvenience I was glad to have avoided.
Similarly, you can buy any EXAIR product with, or without, accessories that’ll make for simpler installation, improved performance, and to ensure it does what you want it to do. Some of these are product-specific, but many are suitable (and recommended) for use with any of our products:
Filter Separators
Good engineering practice calls for point of use filtration for any compressed air operated device. Even if you have the best intake & discharge filters on your air compressor, trace amounts of contaminants can sneak through, pipes can rust, and water vapor that the dryer doesn’t catch can condense. Particulates can build up and eventually clog the tight clearances in many engineered compressed air products, and if you’re using air for cleaning, drying, etc., keep in mind that whatever’s in your air will get on your product. Moisture isn’t always as big of a deal, but it can freeze inside Vortex Tubes, Spot Cooling Products, Cold Guns, and Cabinet Cooler Systems. That’s why we include Filter Separators in our Air Knife, Air Wipe, Static Eliminator Products, Line Vac, Adjustable Spot Cooler, Cold Gun, and Cabinet Cooler System Kits.
Automatic Drain Filter Separators come in sizes from 1/4 NPT to 1-1/4 NPT, for compressed air flows up to 400 SCFM.
Oil Removal Filters
These aren’t always needed, but we have them if your application calls for it. Some of the “usual suspects” are food & Pharma (see above “whatever’s in your air will get on your product”), blowoff prior to painting (the smallest amount of oil on the surface causes a phenomenon known as “fish eye” and it looks exactly like that sounds), or when your compressor is known to have oil carryover.
When properly installed downstream of an Automatic Drain Filter Separator (left,) an Oil Removal Filter (center) will provide clean, oil free air to the Pressure Regulator (right) and all downstream components.
Pressure Regulators
One of our Six Steps To Optimizing Your Compressed Air System is to control the air pressure at the point of use to minimize air consumption. In other words, find the supply pressure for your product that gets the job done, so you don’t use any more compressed air than you have to. Like the Filter Separators above, these come with many EXAIR Intelligent Compressed Air Product Kits.
Pressure Regulators “dial in” performance to get the job done without using more air than necessary.
Mounting Brackets and Coupling Kits
Most of our Filter Separators, Oil Removal Filters, and Pressure Regulators can be attached to a wall, panel, etc., with a Mounting Bracket, and can actually be attached to each other with a modular Coupling Kit. These parts simplify the installation, ensure they are oriented correctly, and minimize the chance for air leaks.
Filters (left) and Pressure Regulators (center) can be mounted using Brackets, and they can be connected together with Modular Couplers (right).
Silencing Mufflers
Many EXAIR products are engineered to develop a boundary layer of low velocity air flow that greatly reduces the sound level during operation. Other products use a venturi mechanism to draw a vacuum (Reversible Drum Vacs and E-Vac Vacuum Generators) or a Vortex Tube to generate cold air flow. The air flow from these products cannot be subjected to back pressure, and, without anything to mitigate the sound pressure generated by the rapid pressure drop as the air exits, they can be quite loud. For these, we have Silencing Mufflers that, except for the largest & most powerful of these products, reduce the sound level to be compliant with OSHA Standard 1910.95 Maximum Noise Exposure Limits.
From left to right… Reclassifying Mufflers offer the highest noise level reduction, eliminate oil mist, and come in sizes from 1/8 NPT to 1 NPT. Sintered Bronze Mufflers are low cost and compact, with threads from #10-32 to 1-1/2 NPT. Straight Through Mufflers use an internal sleeve of sound reducing foam, with threads from ¼ NPT to ¾ NPT, with male threads on one end and female threads on the other. Heavy Duty Mufflers have an aluminum shell and an internal stainless steel screen that keeps contaminants like rust from being ejected in a dangerous way. We have them in ¼ NPT and ¾ NPT sizes.
Solenoid Valves (left) are available for 120VAC, 240VAC, and 24VDC in sizes from 1/4 NPT to 1 NPT. We offer manual Ball Valves in sizes from 1/8 NPT to 1-1/4 NPT.
Swivel Fittings, Stay Set Hoses, and Magnetic Bases
EXAIR Super Air Nozzles are threaded for installation with common air pipe & hose fittings. If the pipe isn’t pointed in the exact right direction, a Swivel Fitting gives you 50° of adjustability. If the pipe isn’t quite close enough to what you want to blow off, Stay Set Hoses come in lengths of 6″ to 36″, and when bent to aim the Air Nozzle, they ‘stay set’, as advertised, until they need to be moved. If a pipe doesn’t exist and you need to run an air hose from the nearest drop on the header, Magnetic Bases can support the Air Nozzle and a Stay Set Hose to get the air where you want it. They even have shutoff valves to turn them off when they’re not in use (that’s a good thing; see above).
Save installation time AND get your blowoff pointed in the right direction!
Hoses and Compressed Air Fittings
If you need one of the aforementioned air hoses to reach a Magnetic Base or to supply a Safety Air Gun, we have two diameters to choose from – 3/8″ ID (1/4 MNPT threads on the ends) and 1/2″ ID (1/2 MNPT threads on the end), and we can make them to any length you need. And, while our selection probably isn’t quite as comprehensive as your local piping supply shop, we stock a number of pipe nipples, Couplers, Reducers, Tees, and Elbows that are commonly used with our products. So – like my backup sump pump deluxe kit, we can put all the fittings you may require in the same box for you.
Contact an Application Engineer if you have ANY questions about how to properly supply compressed air to your EXAIR products.
At EXAIR, we’re here to make sure you get the most out of our products, and your compressed air system. If you need accessories to help with that, give me a call.
Russ Bowman, CCASS
Application Engineer Visit us on the Web Follow me on Twitter Like us on Facebook
EXAIR Manufactures a variety of intelligent compressed air products that can cool, clean, coat, convey, and conserve. They’re designed specifically with enhanced efficiencies, OSHA safety, and high quality in mind. What could make our products even better? Making them movable, with the ability to aim them exactly where you need them! EXAIR offers Magnetic Bases and Stay Set Hoses to achieve this. In this blog, I will cover the features and benefits of both products.
Offered in Lengths of 6″ to 36″
Stay Set Hoses:The Stay Set Hose gives you that possibility of manually adjusting and re-adjusting smaller EXAIR products like Super Air Nozzles and Air Jets. The hose has a “memory” function, and it will not creep or droop until you physically move it. They work very well in directing the air flows at specific target areas. The Stay Set Hoses come in lengths from 6” (15cm) to 36” (91cm), and they have threaded connections with either ¼” NPT male on both ends or with a 1/8” NPT female X ¼” NPT male thread. The hoses are made from reinforced synthetic rubber and have a pressure rating of 250 PSIG (17 bar). They can add versatility to our Safety Air Guns and Blow-off Stations. If you need positioning for precise blowing or adjustments for different targets, the Stay Set Hoses would be a nice addition to include with your EXAIR products.
Top Left: 9042 , Top Right 9043, Bottom 9029
Magnetic Bases: If you need a solid mount to steel surfaces or to move your blow-off system to different locations, a Magnetic Base will allow you to do these functions. It has a 100 lb. (45.5Kg) pulling force to keep the blowing device attached firmly until you want to move it. They can be mounted in a vertical or horizontal position. EXAIR offers a single outlet Magnetic Base or a dual outlet Magnetic Base (for multiple blowing products). The bases come with a ¼ turn shut-off valve to easily turn on and off the compressed air to the EXAIR products. If you want to combine the Stay Set Hoses and Magnetic Bases with your EXAIR Air Nozzles and Air Jets, we can create this with the EXAIR Blowoff System. We can combine multiple parts into a single model number. At EXAIR, we pride ourselves with great customer service and an “easy to do business” philosophy. You can contact a friendly Application Engineer to build an efficient, safe, and movable system just for you.
EXAIR engineered Air Nozzles are quiet, efficient, and safe, which makes them ideal solutions for air blowing applications. Selection is largely determined by the size & shape of the desired air flow. Our Air Nozzles & Jets catalog section lists them all, from smallest to largest, along with performance data and airflow patterns, so determining the right one for your application is pretty easy.
The next question is, how do you install it? If it’s replacing another blowing device, odds are, you’re an adapter fitting away (if that) from a quick & easy install:
Compression fittings and Model 1100 Super Air Nozzles transformed the part ejection on this press from “loud and wasteful” to “quiet and efficient” in about a minute.
Swivel Fittings for Air Nozzles.
For new installations, your compressed air drop may be located some distance from the installation. Properly sized pipe or hose can get you from the drop to the point of installation, but what happens when you get there? If you use hard pipe, and you can run it right to the spot where you want the air to blow, your Air Nozzle will essentially be as well supported as the piping. A Swivel Fitting will then allow you to aim it precisely.
Compressed air hose is inexpensive and easy to work with, but it provides no support for a blow off device at the point of use. This is where EXAIR Blowoff Systems come in. Any EXAIR Air Nozzle, up to our 1/4 NPT models, can be fitted with a Stay Set Hose which, all by itself, could be used at the end of a properly supported piping run instead of a Swivel Fitting. It’ll give you more reach – they come in lengths from 6″ to 36″ – and more flexibility in adjustment than the Swivel Fittings.
Precise aiming and location is a breeze with EXAIR Stay Set Hoses.
If you don’t have a pipe manifold like the one shown above, but you have an iron or steel surface in close proximity, a Magnetic Base can be used. EXAIR offers three styles:
Model 9042 Single Outlet Mag Base (left), 9043 Dual Outlet Mag Base (center) and 9029 Swivel Mag Base (right), and some typical uses.
If you’re looking for an efficient, quiet, and safe method of blowing compressed air, EXAIR has you covered with a wide variety of Intelligent Compressed Air Products to choose from. If you have questions about them, or how to mount them for optimal performance, give me a call.
Russ Bowman, CCASS
Application Engineer EXAIR Corporation Visit us on the Web Follow me on Twitter Like us on Facebook
