The EXAIR Super Air Knife is THE ideal, efficient, and quiet solution for most any blow off application. We know this for a fact; we’ve been making them for years, folks all around the world have been buying them for years, and they keep coming back for more. They’re popular enough that over the years, we’ve introduced Mounting Systems and Plumbing Kits for ease of installation, and when Coupling Kits (to join multiple Super Air Knives together for greater lengths) became big sellers, we “upped our game” and started making Super Air Knives up to nine feet (108″) long. And certain applications (I’m looking at YOU, lumber and paper industries) order multiples of THOSE, and our Coupling Kits. Quite literally, there’s no job too big for EXAIR Super Air Knives.
No matter how long they are, though, the laminar, high velocity curtain of air they generate only moves in one direction. So, if there are significant geometric features (holes, bosses, recesses, “nooks & crannies,” etc.) to be blown off, we’ll have to look at something supplemental.
Enter the EXAIR Blowoff Systems…it doesn’t get any easier than this: an EXAIR engineered Super Air Nozzle, attached to a flexible, repositionable Stay Set Hose, mounted to a Magnetic Base. Put a hard hitting, high velocity, pointed flow of air right where you want it. If the next piece is different, that’s no problem – just bend the hose to re-aim the air flow.
No matter what the requirements of your blow off application are, we have an efficient, quiet, and safe solution. If you’d like to find out more, give me a call.
An overseas company contacted me about an issue with drying copper wires. Their production process utilized fourteen wire drawing machines in their facility. They could make very fine wire in the range of diameters from 0.2mm to 2.6mm. Some of their drawing machines were able to make a maximum of sixteen wires at the same time.
Each wire is made by a process of drawing and annealing. The machine will draw a thicker copper wire through dies that will get progressively smaller in diameter. Before the material goes through the dies, the copper is annealed to make it ductile and workable. Annealing is a process of heating to make the material softer.
In this application, once the wire was to the correct diameter, it would go through a coolant bath to cool and harden. To remove the coolant from the wires, it would travel over a set of drying cloths. From there, the wire would travel out of the drawing machine and into a spooler.
The spooler places the wire onto a spool for packaging and shipping. The reason that they contacted EXAIR was because the wires were not properly dried before it went to the spooler. If any coolant was left on the surface, it would corrode the wires in that area. They needed a better way to dry the wires because they started to receive complaints from their customers.
When the company first contacted me, they had an interest in the Super Air Wipes. The Air Wipes are designed to blow air in a 360 deg. pattern around the wire to dry the entire surface. But, after getting more details about their process, the sixteen wires were coming out of the drawing machine at 1.75cm apart.
With the gap between the wires being so small, the Super Air Wipes would not be able to fit around each wire. As another engineered solution, I recommended the Super Air Knives Kit, model 110212. The Super Air Knives are 12” long (30.5cm) to span across all sixteen wires. The kit includes a filter, regulator, and shim kit to accommodate different forces for different wire speeds.
The Super Air Knife can blow a laminar flow of air consistently across the entire width. Air, as a fluid, likes to “hug” the surface. Since the air stream isn’t turbulent, the contact time along the surface of the wire will be much longer; making it very effective at removing liquid.
I had the customer mount one Super Air Knife above and one Super Air Knife underneath, spanning across the entire row of wires. They were positioned at a 45 deg. angle to blow in the opposite direction the wires were traveling.
Being compact, the Air Knives could be placed at a close distance near the drawing machine to blow the excess coolant back into the machine. This would keep the floor clean and safe from coolant collecting on the ground. So, no matter the diameter of wires being drawn through the machine, the Super Air Knives would be a non-contact way of drying the surface without having to use the drying cloths which were inconsistent and had to be replaced often.
If you require a non-contact way of keeping your product clean and dry, EXAIR has many products to tackle this. No matter how large or small of a profile, we can efficiently and effectively accomplish this. You won’t have to replace items that wear or cause damage to your product by improper contact. EXAIR has the ability to use compressed air to create a strong force without scraping or scratching your material.
A few weeks back I chatted with a customer on an Air Knife application where they were using our 48″ aluminum Super Air Knife to remove leftover dough from a baking pan. The knife was working somewhat, but they were seeing some residual dough being left in certain areas on the pans due to what they perceived as “weak” airflow. After reading through our catalog and installation guide, they noticed that there were available shim sets that would allow them to increase the gap setting to get more force and flow out of the knife.
Our aluminum Super Air Knives are shipped from stock with a .002″ shim installed. The optional shim set includes a .001″, .003″ and .004″ shim that would allow you to decrease or increase the performance. By operating the Super Air Knife with the .003″ shim installed, this would increase the force and flow by 1.5 times and using the .004″ shim would double the performance. Sometimes achieving greater force and flow may be required but with the customer saying they were seeing weak airflow, it seemed there may be a restriction on the supply side.
I asked the customer how the knife was plumbed and what size supply lines he was using. He advised that they were plumbing air to all 3 inlets on the bottom of the knife but they were using 3/4″ hose with a run of about 30′. I advised the customer that plumbing air to all 3 inlets is required for a 48″ Super Air Knife but we actually recommend 3/4″ Schedule 40 Pipe up to 10′ or 1″ pipe up to 50′. If using hose, he would need to go up a size to maintain a large enough ID to carry the volume required for the unit. In his case, since the length of the supply is close to 30′, he would need to use 1-1/4″ ID hose.
Improper plumbing line size is a common issue we deal with here at EXAIR. Using undersized supply lines can cause excessive pressure drops because they aren’t able to carry the volume of air necessary to properly supply the compressed air device. In this particular application, if the customer were to install either the .003″ or .004″ shim, while keeping his current plumbing size, the performance would actually be worse as now the lines are even more undersized due to the increased air volume requirement from the larger Super Air Knife gap.
If you are looking to change the performance with one of our Air Knives or if you would like to discuss a particular application or product, please contact one of our application engineers for assistance at 800-903-9247.
Many times when we provide the air consumption of an EXAIR product, we get a response like…. “I’ve got plenty of pressure, we run at around 100 PSIG”. While having the correct pressure available is important, it doesn’t make up for the volume requirement or SCFM (Standard Cubic Feet per Minute) needed to maintain that pressure. We commonly reference trying to supply water to a fire hose with a garden hose, it is the same principle, in regards to compressed air.
When looking to maintain an efficient compressed air system, it’s important that you use properly sized supply lines and fittings to support the air demand (SCFM) of the point-of-use device. The smaller the ID and the longer the length of run, it becomes more difficult for the air to travel through the system. Undersized supply lines or piping can sometimes be the biggest culprit in a compressed air system as they can lead to severe pressure drops or the loss of pressure from the compressor to the end use product.
Take for example our 18″ Super Air Knife. A 18″ Super Air Knife will consume 52.2 SCFM at 80 PSIG. We recommend using 1/2″ Schedule 40 pipe up to 10′ or 3/4″ pipe up to 50′. The reason you need to increase the pipe size after 10′ of run is that 1/2″ pipe can flow close to 100 SCFM up to 10′ but for a 50′ length it can only flow 42 SCFM. On the other hand, 3/4″ pipe is able to flow 100 SCFM up to 50′ so this will allow you to carry the volume needed to the inlet of the knife, without losing pressure through the line.
We also explain how performance can be negatively affected by improper plumbing in the following short video:
Another problem area is using restrictive fittings, like quick disconnects. While this may be useful with common everyday pneumatic tools, like an impact wrench or nail gun, they can severely limit the volumetric flow to a device requiring more air , like a longer length air knife.
For example, looking at the above 1/4″ quick disconnect, the ID of the fitting is much smaller than the NPT connection size. In this case, it is measuring close to .192″. If you were using a device like our Super Air Knife that features 1/4″ FNPT inlets, even though you are providing the correct thread size, the small inside diameter of the quick disconnect causes too much of a restriction for the volume (SCFM) required to properly support the knife, resulting in a pressure drop through the line, reducing the overall performance.
If you have any questions about compressed air applications or supply lines, please contact one of our application engineers for assistance.
Sometimes you need more power. I received a phone call from a bottling facility that was currently using a blower style type of air knives. They increased their production rate from 220 bottles/min to 300 bottles/minute, and they started to see issues in the labeling process. Their operation consisted of a wash cycle, rinse cycle, drying cycle, then labeling. They determined that the bottles were not getting dry enough during the drying cycle before the labels were applied. They had a VFD (Variable Frequency Drive) for the blower system, and they reached the maximum rate. Still the bottles were not getting dry enough to allow the label to stick to the surface properly. This meant that they would have to increase the size of their blower system. With the capital cost of a blower system, they decided to call EXAIR to see if we could help them with the drying application.
Compressed air is the best way for establishing a strong blowing force. Instead of air pressures in the range of inches of water, the compressed air system can generate over 40 times the amount of pressure than a typical blower system. EXAIR products uses this power of the compressed air to give you a wide range of blowing forces for drying, cooling, or moving products. For the above application, I recommended two model 110212 Super Air Knife kits. The kit includes the Super Air Knife, a filter, a regulator, and a shim set. They mounted one knife on each side of the bottles to blow off and remove the liquid after the rinse cycle. Even at the increased bottle speeds, the EXAIR Super Air Knives had no issues in keeping the bottles dry. With the regulator and the shim, it was easy for them to dial in the correct amount of force without using excess compressed air. The labels remained glued and the bottling process ran smoothly. Because the company was impressed by the Super Air Knives, they wanted to comment on the comparisons between the blower knife and the Super Air Knife.
Blower System – The reason for contacting EXAIR. Blower-type air knives are an expensive set up. They require a blower, ducting, and a knife. To have any flexibility, a control panel with a VFD will be needed.
Super Air Knife – It is a fraction of the cost. With their system, we were roughly 1/10 the cost; even with the kit. No capital expense report would be needed for the two air knives.
Blower System – They stated that it took them a week to install the entire system before they were able to operate. They had to run electrical wires, controls, ducting, and they even had to change the conveying system slightly to accommodate the blower size.
Super Air Knife – They mounted the filter and the regulator on the conveyor, and ran tubing to the Super Air Knives. Even with a fabricator making a bracket to fit into their system, they had the system up and running is less than two hours.
Blower System – The foot print of the blower is large and it takes up floor space. The 3” ducting had to be ran to an oversized air knife. With the congestion of the bottle system, it made it difficult to optimize the position and the blowing angle to adequately dry the bottles.
Super Air Knife – With the compact design, the Super Air Knife packs a large force in a small package. It has a footprint of 1 ¾” X 1 ½” X 12” long. The air knife only required a ¼” NPT compressed air line to supply the compressed air. It opened up the floor space as well as the bottling area.
Blower System – The blower filter had to be changed regularly, and system had to be checked. Being that the blower motor is a mechanical device, the bearings will wear and the motor will fail over time. These items should be checked quarterly as a PM which increase the cost to run the system.
Super Air Knife – No moving parts to wear out. The only maintenance would be to change the filter once a year.
Blower System – They did have a VFD to control the blowing force. But it was still very limited. With a 36% increase in the bottle speed, they went beyond the maximum capacity of the blower.
Super Air Knife – With a regulator and the shim set, the blowing force can be controlled easily from a breeze to a blast. With their application, the customer only required 40 psig with a standard 0.002” shim to clean and dry the bottles. They had the option to adjust the regulator or change the shim to get the appropriate amount of blowing force. So, with any changes in the bottling operations, the Super Air Knife could easily be adjusted. Also, with the blowing force being optimal from a distance of 3” to 12” from the target, they had more flexibility in angle and distance to hit the moving target.
Blower System – With the blower and turbulent air flow, the units are very loud. It had a sound level near 93 dBA, and with the operators working around the system, they needed PPE to protect them from the high potential of noise induced hearing loss.
Super Air Knife – These units are very quiet. At 40 PSIG, the sound level is only at 61 dBA. (Even operating at a pressure of 100 PSIG, the sound level is only 72 dBA). This was very nice for the operators to work around as it wasn’t a constant noise nuisance.
In using the compressed air, the Super Air Knives are engineered to be very efficient. The design creates a 40:1 amplification ratio which means that for every 1 part of compressed air, 40 parts of the ambient air is entrained. But, even with the use of compressed air, the customer still wanted to share the ease of installing, the effectiveness of blowing, and the improvements to their process. With the 6 points noted above, the customer wished that they would have contacted EXAIR at the beginning.
Blowing off bottles is such a popular application for the EXAIR Super Air Knife, it’s been featured on the cover of our Catalog…several times…and is the “banner” pictures on the Super Air Knives page on our website:
I had the pleasure of helping a caller from a bottling plant recently with just such an application. Thing is, they run a couple of different size bottles, and it’s not a very big facility…they didn’t want to, or have room to, install different lengths of Air Knives, and also didn’t want to waste air flow when they were running the shorter bottles.
9″ Air Knives were required for the taller bottles, but their shorter bottles were a little under 6″ tall. They had considered buying both 6″ and 9″ Air Knives, but called me to see if there was a less expensive, and possibly, easier way. (There is!)
EXAIR makes, and stocks, every product in our 208 page catalog right here in this building in Cincinnati, Ohio. We also make custom parts when the need arises…and custom Air Knife shims were the solution to this customer’s application.
By installing two Model 110009 9″ Aluminum Super Air Knives, one on either side of the conveyor (just like the photo above,) they’re able to blow off the taller bottles. When they run the shorter bottles, they change out the shims for ones that limit the flow to a 6″ curtain.
So…for a little under $50.00 (2017 cost for those custom shims,) they’re going to save almost $550.00 per year in compressed air costs – AND make sure that their compressed air system is optimized & available for other loads throughout the plant.
EXAIR offers the Super Air Knife in lengths from 3″ to 108″, with a 0.002″ shim installed. They’re ideal for most industrial and commercial blow off applications, right out of the package. If your application calls for something a little “outside the box,” you may only be a shim away from success. If you have such an application, give me a call.
EXAIR manufactures three different styles of Air Knives; Super, Standard, and the Full Flow. In this excerpt, I am going to discuss the Standard Air Knives.
The Standard Air Knife uses a Coanda profile for blowing. The Coanda effect was named after a Romanian aerodynamic pioneer, Henri Coanda where he found a fluid phenomenon. He stated that “a jet of fluid emerging from an orifice to follow an adjacent flat or curved surface and to entrain fluid from the surroundings so that a region of lower pressure develops” (1). Being that air is a fluid, it will react in the same manner.
The EXAIR Standard Air Knife creates a high velocity air stream along an engineered profile. So, as the air “hugs” the profile, a low pressure is created which will draw in ambient air. What does this mean for you? It will use less compressed air to save you money. For the Standard Air Knife, it has an amplification ratio of 30:1. (For every 1 part of compressed air, 30 parts of ambient air is drawn into the stream). This design makes the product very efficient. We can use less compressed air and bring in more of the free ambient air to create a strong blowing force.
We make the Standard Air Knife in various lengths from 3” to 48” (76mm to 1219mm). We make the air knives in two different materials, aluminum and stainless steel. The unique design is very compact; so, it can fit into tight places for blowing and cooling. The aluminum version uses plastic shims to set the gap. They come standard with a 0.002” shim installed. We have additional shims to make the Standard Air Knife more versatile. The shim set includes a 0.001”, 0.003”, and a 0.004” thickness shim for applications that may require a small breeze up to a strong blast of air. The shims are color coded for easy verification. The stainless steel Standard Air Knife comes with a stainless steel shim for higher temperatures or chemical resistance.
We do offer the Standard Air Knives in kits for a more complete package. It comes with a filter, regulator and the above mentioned shim kit. The filter removes the debris and water from the compressed air line to optimize the performance of the air knife as well as keeping your product clean. The regulator is used to make “fine” adjustments to the blowing force. The shim set is used as a “coarse” adjustment to the blowing force. Together, you can “dial” in the right amount of air required to do the job without wasting compressed air.
For easy mounting, we do offer a Universal Air Knife Mounting System. This kit is used to position your air knife securely and precisely. It comes with a bracket and an articulated arm that can reach up to 30” (762mm). You can orient the Standard Air Knife in any position to maximize the effectiveness.
With the today’s cost to make compressed air, it is important to do it as efficiently as possible. The Standard Air Knife has the ability to give you the effective blowing for removing debris, drying parts, or cooling objects without using a large amount of compressed air. As an additional feature, the Standard Air Knife only has a sound level of 83 dBA at 80 psig (5.5 bar). So, in using this EXAIR product, you are not creating a noise nuisance in the work environment. If you have any questions about the Standard Air Knife or if you would like to discuss an application, you can contact an Application Engineer at EXAIR.