Provides the best performance with a 40-1 air amplification ratio, making it the most efficient. It is the best choice for all applications.
In industrial applications, air knives offer an efficient way to clean, dry or cool parts, webs or conveyors as well as acting as an environmental separator or air curtain. EXAIR's Super Air Knife is the most efficient compressed air knife on the market! It delivers a uniform sheet of laminar airflow across the entire length with hard-hitting force.
It is engineered to dramatically reduce compressed air usage while entraining ambient air at a ratio of 40-1. Noise levels are greatly reduced when compared to other blowoffs.
Available from stock 3" to 108" long and made from aluminum, Type 303 stainless steel, Type 316 stainless steel and PVDF to meet your application needs. Custom sizes and materials available. Please contact us.
What is The Super Air Knife?
EXAIR's Super Air Knife is the latest generation of our engineered air knife that dramatically reduces compressed air usage and noise when compared to other blowoffs. The Super Air Knife offers more efficient way to clean, dry or cool parts, webs or conveyors. It delivers a uniform sheet of laminar airflow across the entire length with hard-hitting force.
Noisy blowoffs become a whisper when replaced with the compact Super Air Knife. Even at high pressure of 80 PSIG (5,5 BAR), the sound level is surprisingly quiet 69 dBA for most applications! Air amplification ratios (entrained air to compressed air) of 40:1 are produced. Meets OSHA maximum dead-end pressure and noise requirements.
Performance:
Advantages:
Applications:
How the Super Air Knife Works?
Compressed air flows through an inlet (1) into the plenum chamber of the Super Air Knife. The flow is directed to a precise, slotted orifice. As the primary airflow exits the thin slotted nozzle (2), it follows a flat surface that directs the airflow in a perfectly straight line. This creates a uniform sheet of air across the entire length of the Super Air Knife. Velocity loss is minimized and force is maximized as the room air (3) is entrained into the primary airstream at a ratio of 40:1. The result is a well defined sheet of laminar airflow with hard-hitting force and minimal wind shear.
Intelligent Use Of Compressed Air
Almost every industrial facility has at least one compressor that is used for hundreds of different tools, equipment and operations. While most applications for compressed air present no real problems, some do. Improper use can translate into unnecessary energy costs, high noise levels and dangerous exposure of personnel to high pressure air.
Reduce Energy Costs
The best way to cut energy costs is through proper maintenance and use of the compressed air system. Leaks and dirty filters require maintenance on a regular basis. Energy savings can also be realized when replacing outdated motors and controls with high efficiency models that often pay for themselves in a short period of time. The most important factor to dramatically boost efficiency is to use proper compressed air products. The Super Air Knife uses only 1/3 of the compressed air of typical blowoffs.
OSHA MAXIMUM ALLOWABLE NOISE EXPOSURE
High noise levels are a common problem for many plants. Compressed air noise often exceeds OSHA (Occupational Safety and Health Administration) noise level exposure requirements, resulting in hearing loss to those working in close proximity. The sound level of the Super Air Knife is quiet at 69 dBA, even at high pressures of 80 PSIG (5.5 BAR). Using the Super Air Knife, it is possible to obtain hard-hitting force without the high noise.
Eliminate Harmful Dead End Pressures
Air can be dangerous when the outlet pressure of a hole, hose or copper tube is higher than 30 PSIG (2 BAR). In the event the opening is blocked by a hand or other body part, air may enter the bloodstream through the skin, resulting in a serious injury. The Super Air Knife has been engineered for safety and cannot be dead-ended. It is safe to operate at higher pressures and complies with OSHA standard 1910.242(b).
Replacement For Expensive, Noisy Blowers
Energy conscious plants might think a blower to be a better choice due to its slightly lower electrical consumption compared to a compressor. In reality, a blower is an expensive capital expenditure that requires frequent downtime and costly maintenance of filters, belts and bearings. Here are some important facts:
• Filters must be replaced every one to three months.
• Belts must be replaced every three to six months.
• Blower bearings wear out quickly due to the motor that must turn at 17,000-20,000 RPM in order to generate effective airflows.
• Poorly designed seals that allow dirt and moisture infiltration along with environments above 125°F (52°C) decrease the one year bearing life.
• Typical bearing replacement is at least once a year at a cost near $1000.
• Many bearings can’t be replaced in the field, resulting in downtime to send the assembly back to the manufacturer.
• Many blowers generate heat, making conditions uncomfortable and difficult to use for cooling applications.
Blowers take up a lot of space and often produce sound levels that exceed OSHA noise level exposure requirements. Air volume and velocity are often difficult to control since mechanical adjustments are required.
Compare These Blowoffs!
There are a variety of ways to blow the water from the bottles shown in the photo below, but which method is best? The following comparison of drilled pipe, flat air nozzles, a blower and the Super Air Knife proves that EXAIR has the best choice for your blowoff, cooling or drying application.
Our goal for each of the blowoff choices was to use the least amount of air possible to get the job done (lowest energy and noise level). Compressed air pressure required for each was 60 PSIG (4.1 BAR) which provided adequate velocity to blow the water off. The blower used had a ten horsepower electric motor and was a centrifugal type blower at 18,000 RPM. The table at the bottom of the page summarizes the overall performance. Since your actual part may have an odd configuration, holes or sharp edges, we took sound level measurements in free air (no impinging surface).
DRILLED PIPE
This common blowoff is very inexpensive and easy to make. For this test, we used (2) drilled pipes, each with (25) 1/16" (1.6mm) diameter holes on 1/2" (13mm) centers. As shown in the test results below, the drilled pipe performed poorly. The initial cost of the drilled pipe is overshadowed by its high energy use. The holes are easily blocked and the noise level is excessive - both of which violate OSHA requirements. Velocity across the entire length was very inconsistent with spikes of air and numerous dead spots.
FLAT AIR NOZZLES
As shown above, this inexpensive air nozzle was the worst performer. It is available in plastic, aluminum and stainless steel from several manufacturers. The flat air nozzle provides some entrainment, but suffers from many of the same problems as the drilled pipe. Operating cost and noise level are both high. Some manufacturers offer flat air nozzles where the holes can be blocked - an OSHA violation. Velocity was inconsistent with spikes of air.
ELECTRIC BLOWER AIR KNIFE
The blower proved to be an expensive, noisy option. As noted below, the purchase price is high. Operating cost was considerably lower than the drilled pipe and flat air nozzle, but was comparable to the EXAIR Super Air Knife. The large blower with its two 3" (76mm) diameter hoses requires significant mounting space compared to the others. Noise level was high at 90 dBA. There was no option for cycling it on and off to conserve energy like the other blowoffs. Costly bearing and filter maintenance along with downtime were also negative factors.
EXAIR SUPER AIR KNIFE
The Super Air Knife pair did an exceptional job of removing the moisture on one pass due to the uniformity of the laminar airflow. The sound level was extremely low at 69 dBA. For this application, energy use was slightly higher than the blower but can be less than the blower if cycling on and off is possible. Safe operation is not an issue since the Super Air Knife cannot be dead-ended. Maintenance costs are low since there are no moving parts to wear out.
Super Air Knife Specifications
The Super Air Knife is available in standard lengths of 3", 6", 9" 12", 18", 24", 30", 36", 42", 48", 54", 60", 72", 84", 96" and 108". Special lengths and unlimited system lengths are available. Any number of Super Air Knives may be installed across a given area.
Compressed Air Inlets: A Super Air Knife has compressed air inlets on each end and the bottom. Knives 24"-47" should use the 2 inlets at opposite ends of the knife. Knives 48"-59" use 2 inlets at opposite ends plus 1 near the middle on the bottom of the knife. Knives 60"-83" use 2 inlets at opposite ends plus 2 inlets equally spaced on the bottom of the knife. Knives 84" and longer use 2 inlets at opposite ends plus 3 inlets equally spaced on the bottom of the knife.
Filtration: The use of clean air is essential. Kits include an automatic drain filter with a 5 micron filter element that is sized properly for flow.
Materials of Construction: The Super Air Knife is available from stock in aluminum, Type 303 stainless steel, Type 316 stainless steel and PVDF. Other materials are available on special order.
Mounting: The Universal Air Knife Mounting System is shown on page 29. The Super Air Knife can be supported by the compressed air pipe. Tapped holes (1/4-20) on the bottom are also provided.
Regulation: A pressure regulator on the compressed air supply provides infinite control of flow, force and air consumption. Kits include a pressure regulator that is sized properly for flow.
Shim Sets: The compressed air exhausts through a gap which is set with a shim. Force and flow may be increased by adding shims. Shim sets for aluminum Super Air Knives include a .001" (0.03mm) Amber color , .003" (0.08mm) Green color , and .004" (0.10mm) thick Tan color plastic shims. A Red color .002" (0.05mm) thick shim comes installed in the Super Air Knife. Shim sets for stainless steel Super Air Knives include (3) .002" (0.05mm) stainless steel shims. PVDF Super Air Knife shim sets include (3) .002" (0.05mm) PTFE shims.
Special Super Air Knives
EXAIR manufactures special Super Air Knives suited to specific application requirements. The shape, dimensions and materials of construction can be modified to fit existing machines and environments.
The curved stainless steel Super Air Knife was manufactured for a laboratory that uses the force of the airflow to hold test tubes in place on a rotating index table. They were able to eliminate the mechanical clips and latches that slowed the test tube removal. This holding method minimized risk of tube breakage and eliminated any chance of puncturing the technician’s rubber gloves.
EXAIR manufactures special Super Air Knives made of plastic. These products are engineered to work under normal operating pressures, providing the same performance as their aluminum and stainless steel counterparts.
The PVC Super Air Knife was manufactured for a picture tube plant. The softer material was less likely to scratch the picture tube surface and was chemically resistant to the phosphorus which coated the inside.
The flat Super Air Knife is used in a molding machine for integrated circuit chips. Prior to molding the black plastic shells around the silicon wafers, they blow the mold cavity clean of any fine plastic fibers left by the previous cycle. The flat design constructed of corrosion resistant stainless steel was made to fit the tight space of the molding machine.
The double-sided Super Air Knife provides two uniform sheets of air in opposite directions. It is ideal for blowing water from two or more columns of stacked parts (like printed circuit boards) as they are lifted out of a bath or the open halves of a mold. Each side operates independently.
The Super Air Knife can be modified to include extra mounting holes to suit your application
The Curved Stainless Steel Super Air Knive
A PVC Super Air Knife
Flat Super Air Knife
Double-sided Super Air Knife
Stainless Steel Super Air Knife Extra Mounting
Many Lengths Available From Stock in Four Materials
EXAIR’s Super Air Knives are available from stock in many lengths and your choice of four materials. The force, flow and air pattern stay the same for each construction.
Aluminum
The aluminum Super Air Knife is suited to a wide variety of environments where corrosion or contamination is not a factor. The aircraft grade aluminum construction with plastic shim is very durable for general purpose applications. Stainless steel screws are used to eliminate corrosion in damp locations. It can withstand temperatures up to 180°F (82°C).
Type 303 Stainless Steel
This is the most common grade of stainless steel. It offers good strength and is best suited to mildly corrosive environments. It can withstand temperatures up to 800°F (427°C).
Type 316 Stainless Steel
Some applications require better corrosion resistance than offered by Type 303 stainless steel. Type 316 stainless steel offers excellent corrosion resistance, better strength properties and resists pitting. These factors are important to manufacturers of food, pharmaceutical and surgical products that need to minimize contamination by the metal. It can withstand temperatures up to 800°F (427°C).
PVDF (Polyvinylidene Fluoride)
EXAIR’s Super Air Knife is also available from stock in PVDF (Polyvinylidene Fluoride). PVDF offers superior strength and is resistant to UV light, inorganic chemicals, solvents, ozone, weather, fungi, chlorinated hydrocarbons, highly corrosive acids, weak bases and salts. The PVDF Super Air Knife uses PTFE shims, Type 316 Stainless Steel pipe plugs, and Hastelloy® C-276 alloy screws to withstand harsh environments. The PVDF Super Air Knife is suitable for manufacturing processes that involve electroplating, solar cells, lithium ion batteries, transfer of acids and caustic chemicals, brine, solvent recovery, semiconductors, and medical devices. It can withstand temperatures up to 275°F (135°C).
Here are some case studies:
SUPER AIR KNIFE REPLACES FAN COOLING
The Problem: A manufacturer of automotive electronics had a problem cooling computers as they exited a wave solder machine. In order to be handled and tested, the computers had to first be cooled to 81°F (27°C). Initially, they had tried banks of 6" (152mm) diameter axial fans across the 8' (2.5m) length of the cooling conveyor. It consisted of 16 fans blowing down from the top and 16 fans blowing up from the bottom at 7" (178mm) away from the surface. After traveling the full length of the conveyor with the fans running at full force (a five minute duration), the computers were still 108°F (42°C). Quality control personnel sat with an unacceptable backlog of computers waiting to be tested.
The Solution: The company removed the top and bottom fan banks and replaced them with (3) Model 110012 12" (305mm) Super Air Knives that were evenly spaced across the cooling section. Each Super Air Knife was angled so the computer and heat sink received the constant rush of airflow. With the conveyor at the same speed 1.6 FPM (0.5m/min), and Super Air Knives at only 40 PSIG, the computers were cooled to 81°F (27°C) in 90 seconds!
Comment: The laminar airflow of the Super Air Knives was the key to success in this application. Fan cooling could only provide random spikes of air at moderate velocities. The uniform sheet of air from the Super Air Knife quietly swept the heat away within the first 2' (610mm) of the conveyor. Low air consumption and the compact size of the Super Air Knife were an added bonus.
AIR SHIELDING A LASER LENS
The Problem: A dirty lens can affect the quality of cameras, sensors and lasers. Today’s visual inspection systems are highly accurate tools used to monitor dimensions, temperature, finish quality, labeling and much more. These products require clean lenses in order to provide the proper feedback to operators or other machinery within the process. The above laser lens is integral to a laser cleaning operation where a laser is used to clear away debris and provide a fresh surface. The laser cleaning operation in this case was creating debris which flew up and deposited on to the laser lens. Debris on the lens could affect the laser’s cleaning quality or become burned upon the lens and create the need for a replacement lens.
The Solution: A Model 110006 6” (152mm) Super Air Knife was installed just above the laser lens to blow air down and across the lens. The sheet of air created an invisible barrier the contaminants could not penetrate and kept them from depositing on to the lens. The quality of the laser cleaning has been consistently good and the need for replacement lenses due to debris deposition has been eliminated.
Comment: An air barrier is a common application for a Super Air Knife and can create a non-contact wiper with little or no obstruction. They have been used in similar applications to prevent debris from getting to many different sensors or cameras, to retain heat within an oven, or to deflect mist from a machine tool.
BAKERY CREATES CLEAN BREAK IN ICING
The Problem: A bakery had a problem applying the icing to their snack cakes. As the baked sponge cakes moved down the conveyor, a continuous ribbon of icing was applied to the individual cakes. Trying to make a clean break in the icing was next to impossible. Mechanical blades required constant cleaning. Compressed air through a series of holes in drilled pipe used too much air, was noisy and didn't make a clean break in the icing.
The Solution: A Model 110018SS 18" (457mm) Stainless Steel Super Air Knife was installed across the conveyor. A photo eye is used to detect the space between the cakes and turn the compressed air on at the precise moment to apply uniform airflow and velocity against the ribbon of icing, creating a nice, clean break.
Comment: The Stainless Steel Super Air Knife was the best choice for this application. Since there was no contact with the icing, no additional cleaning was required. The laminar flow of the Super Air Knife has uniform velocity across the entire length and broke the ribbon of icing evenly. This would never have been possible with the spikes of air from a drilled pipe, nozzles or a blower.
SMOKE CONTAINMENT DURING ENGINE TEST
The Problem: The last step in an engine assembly process is "burn-in" on a test stand. Each engine is connected to a dynamometer and run for a period of one to five minutes. Residual machining oil on the head produced smoke during the test, and the vent hood at the top of the stand had insufficient capacity to contain it.
The Solution: A Model 110024 24" (610mm) Super Air Knife was mounted on both sides of the test stand. The sheet or "wall" of air produced by the Super Air Knife, captured, contained and diluted the smoke while directing it towards the vent hood. The environmental problem was solved without obstructing the technicians observation of, or access to the stand.
Comment: The use of the Super Air Knife for containment and separation is becoming increasingly common. The advantage, as illustrated here, is the ability of the Super Air Knife to create a screen or barrier with no obstruction. Other typical applications in this mode are:
Here are some sample of applications:
Model 110006 6" (152mm) Super Air Knife removes residual water from can bottoms after rinse process, eliminating water damage to packaging and shipping materials.
Model 110054 54" (1372mm) Super Air Knife dries stamped parts that exit a washer.
Model 110018 18" (457mm) Super Air Knife cools molten plastic following dip molding.
Fast moving bottles will blown dry by (2) model 110018 18" (457mm) Super Air Knives prior to labeling.
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