What is an Air Knife?
Air Knife Systems utilize compressed air for industrial applications. The curtain-like laminar airflow of the Air Knife (a.k.a. air curtain) is used as a blower system to: dry, clean, remove excess oils, liquids and dust from your application. The Air Knives may also be used for: printing and labeling, part or component cooling, converting and packaging, films and laminating, form and fill, sheet and web materials, bag opening/fill operations, conveying, food processing and paint preparation. Air Knife nozzle design utilizes the Coanda Effect to amplify the air up to 40 times from the inlet making it the most efficient compressed air drying system.
Contents
- What is an Air Knife?
- How does an Air Knife work?
- What types of Air knives do we carry?
- What makes our Air Knives better?
- Compressed Air Knife Systems Applications
- Industrial Air Knife Blower
- Air Knife Drying Systems
- Advantages of Air Knives
- Air Knife Cooling
- Air Knife Case Studies
- Air Knife for Drying Cans
- Ion Air Knife for Remove Static Electricity
- Air Knife for Uniform Sheet of Air
- Air knife FAQs
- Pneumatic Air Knife Design by Streamtek
How does an Air Knife work?
(A) Compressed air enters the inlet at the rear or end ports and flows into a plenum chamber
(B) Surrounding air is entrained by the airflow producing an amplification ratio of 40:1 at a 6 inch distance which adheres to the coanda effect. The knife consists of a high-intensity, uniform sheet of laminar airflow sometimes known as streamline flow.
(C) The airflow now travels straight out of the Air Knife. The amplified air stream is a hard-hitting sheet of laminar flow with minimal wind shear, which reduces energy used in blow-off and cooling applications.
(A) Compressed air flows through the inlet at the rear (or end) ports, and into a plenum chamber.
(B) As the compressed air stream leaves the Air Knife, the surrounding air is entrained into the airflow for an amplification ratio of 30:1 @ 6″ away and adheres to the coanda profile.
(C) The airflow now turns 90 and travels down the front face of the Air Knife. The amplified air stream is a hard-hitting sheet of laminar flow with minimal wind shear, which translated into reduced energy use in blow-off and cooling.
Information
What types of Air knives do we carry?
The Advanced Air Knife provides the best performance with a 40:1 air amplification ratio, making it the most efficient Air Knife Streamtek offers.
The Regular Air Knife provides good performance with a 30:1 air amplification ratio that is less efficient than the Advanced Air Knife. Air consumption is ~3.4 SCFM per inch at 80 PSIG. The Regular Air Knife is a good choice when a less expensive alternative is required. It has slightly higher noise levels and uses more compressed air than the Advanced Air Knife.
Preset Gap
Air amplification ratio
Air consumption @80 PSIG
Material
Noise level
Available Size
.002″
40:1
~2.9 SCFM per inch
Aluminum & Stainless Steel
Low
2″ (51mm) up to 54″ (1372 mm)
.002″
30:1
~3.4 SCFM per inch
Aluminum & Stainless Steel
Medium
3″ (76mm) up to 54″ (1372 mm)
What makes our Air Knives better?
- Finest tools and expertise for air knife production
- End-to-end innovative products for improved usability
- Continuous improvement and upgrading of techniques and methodologies
- Cost-effective products in a cost sensitive market
- Latest and proven technologies used for premium air knife manufacturing
Our Air Knives can be used for superior quality cleaning, cooling, heating or decontaminating. They help in removing dirt, moisture, contamination etc. from the object. Our air knives are energy efficient and do not require heavy maintenance. Right from inception, we have created a mark in the industry by offering the most effective products. Honesty and integrity are our stepping stones and we have worked hard towards every milestone we have achieved. See other Steamtek products like 55 gallon drum pumps and other pneumatic components.
Specifications
The Advanced Air Knife is available in thirteen standard IN-STOCK lengths of 2″ (51″), 3″ (76 mm), 6″ (152 mm), 8″ (203 mm), 9″ (229 mm), 12″ (305 mm), 18″ (457 mm), 24″ (610 mm), 30″ (762 mm), 36″ (914 mm), 42″ (1067 mm), 48″ (1219 mm), and 54″ (1372 mm).
The Regular Air Knife is available in twelve standard IN-STOCK lengths of 3″ (76 mm), 6″ (152 mm), 8″ (203 mm), 9″ (229 mm), 12″ (305 mm), 18″ (457 mm), 24″ (610 mm), 30″ (762 mm), 36″ (914 mm), 42″ (1067 mm), 48″ (1219 mm), and 54″ (1372 mm).
| Air Knife Material Comparison | ||
| Temperature Rating | Corrosion Rating | |
| Aluminum Air Knife | 275°F (135°C) | Low |
| Stainless Steel (Type 303) Air Knife | 400°F (204°C) | Medium |
| *Stainless Steel (Type 316) Air Knife | 800°F (427°C) | High |
| *Available upon special request | ||
Materials:
Streamtek Air Knives are available in both aluminum and stainless steel construction. Unlike our competitors who opt for plastic, we use only stainless steel shims and screws to ensure durability and longevity.
Mounting:
There are multiple ¼”-20 mounting holes located on the rear face of the Air Knife (see Dimensions tab for illustration). Streamtek also offers optional Air Knife Mounts for a faster and easier setup. Our mounts feature a magnetic base with an ON/OFF switch and 80 lbs of holding force. Visit our Accessories section for more details.
Shims
All Streamtek Air Knives include a .002″ stainless steel shim which is suitable for most applications. If more force is required, additional shims can be installed for greater force and airflow. Shims are stackable, which means that multiple shims can be used on one Air Knife.
Compressed Air Inlet(s):
Our Air Knives feature air inlet(s) at each end* and on the rear face to allow for flexible air connection. A simple ¼” NPT male fitting is all that is required for air connection. Air connection at two inlets is recommended on sizes over 36”. * Excluding 2″ and 3″ (76 mm) models.
Air Supply Filtration Since air passes through a small gap in our Air Knives, a clean and dry source of compressed air is vital to avoid dead spots. We recommend using a Streamtek 5-Micron Auto Drain Filter for all Air Knife setups.
| Advanced Air Knife Performance | ||||||||
| Pressure Supply | Air Consumption Per Inch (25mm) | Velocity @ 6″ (152mm) from target | Sound Level @ 3′ (914mm) | Force Per Inch (25mm) @ 6″ (152mm) from target | ||||
| PSIG | BAR | SCFM | SLPM | FPM | M/S | dBA | Ounces | Grams |
| 20 | 1.4 | 1.3 | 36 | 5,000 | 25 | 56 | 0.6 | 17 |
| 40 | 2.8 | 1.7 | 48 | 7,000 | 36 | 61 | 1.1 | 31 |
| 60 | 4.1 | 2.1 | 59 | 9,600 | 49 | 65 | 1.8 | 51 |
| 80 | 5.5 | 2.9 | 82 | 11,800 | 60 | 68 | 2.5 | 71 |
| 100 | 6.4 | 3.3 | 93 | 13,500 | 69 | 71 | 3.2 | 91 |
| Regular Air Knife Performance | ||||||||
| Pressure Supply | Air Consumption Per Inch (25mm) | Velocity @ 6″ (152mm) from target | Sound Level @ 3′ (914mm) | Force Per Inch (25mm) @ 6″ (152mm) from target | ||||
| PSIG | BAR | SCFM | SLPM | FPM | M/S | dBA | Ounces | Grams |
| 20 | 1.4 | 1.5 | 42 | 4,000 | 20 | 64 | 0.5 | 14 |
| 40 | 2.8 | 2.1 | 60 | 5,800 | 30 | 73 | 1.2 | 34 |
| 60 | 4.1 | 2.7 | 77 | 8,500 | 43 | 80 | 2.0 | 57 |
| 80 | 5.5 | 3.5 | 99 | 11,000 | 56 | 83 | 2.8 | 79 |
| 100 | 6.4 | 4.1 | 16 | 13,000 | 66 | 86 | 3.3 | 94 |
| Drilled Pipe Air Consumption: Chart *Compressed Air Flow Trough A Hole in Standard Cubic Feet Per Minute (SCFM) | ||||||||||
| 1/16″ (1.59mm) Diameter Hole | 3/32″ (2.38mm) Diameter Hole | 1/8″ (3.18mm) Diameter Hole | 3/16″ (4.76mm) Diameter Hole | 1/4″ (6.35mm) Diameter Hole | ||||||
| PRESSURE SUPPLY | SCFM | SLPM | SCFM | SLPM | SCFM | SLPM | SCFM | SLPM | SCFM | SLPM |
| 20 PSIG (1.4 Bar) | 1.5 | 42.4 | 3.4 | 96.2 | 6.3 | 178.3 | 14.7 | 416.0 | 26.0 | 735.8 |
| 40 PSIG (2.8 Bar) | 2.1 | 65.0 | 5.5 | 155.7 | 10.1 | 285.8 | 23.0 | 650.9 | 40.0 | 1132.0 |
| 60 PSIG (4.1 Bar) | 3.1 | 87.7 | 7.5 | 212.3 | 14.2 | 401.9 | 31.0 | 877.3 | 54.0 | 1528.2 |
| 80 PSIG (5.5 Bar) | 3.9 | 110.4 | 9.4 | 266.0 | 17.5 | 495.3 | 40.0 | 1132 | 70.0 | 1981.0 |
| 100 PSIG (6.4 Bar) | 4.6 | 130.2 | 11.7 | 331.1 | 21.7 | 614.1 | 47.5 | 1344.3 | 83.0 | 2348.9 |
| 120 PSIG (8.4 Bar) | 5.4 | 152.8 | 13.9 | 393.4 | 25.9 | 733.0 | 56.3 | 1593.3 | 96.0 | 2716.8 |
The drilled pipe is a relatively inexpensive and easy product to use. As shown in the test above, the drilled pipe performs poorly. Due to its high compressed air use, the initial cost of the drilled pipe is quickly over taken. In addition, OSHA requirements are violated as the noise levels are excessive and holes can easily become blocked. Due to the nature of drilled pipe, air flow across the entire length is not uniform; resulting in many dead spots and spikes of air.
Performance Graphs
Compressed Air Knife Systems Applications
The Streamtek Air Knife uses innovative compressed air technologies to improve productivity, increase equipment efficiency, deliver enclosure cooling, spot cooling, conveying, and blow-off. If you don’t find a solution and/or idea for your application, or if you want additional details, call our factory at 1-705-770-4455 or email an Application Engineer at support@stream-tek.com.
Industrial Air Knife Blower
- Clean circuit board holes, flat sheet rubber and plastic; moulds.
- Blow off liquid, chemicals, dirt, chips, and/or water prior to labeling or packaging.
- Remove water, coolant, dust, and scrap in parts manufacturing and assembly operations.
- Paper dust removal and control.
Air Knife Drying Systems
- Bottles and cans, castings, sheet metal, and dip tank solution stripping.
- Extrusions, wire, produce, wood preservative, drive-thru car wash, paint, coatings, and cloth.
Advantages of Air Knives
- Quiet (69 dBA for most applications)
- Minimal air consumption (40:1 air amplification)
- Variable force and flow
- No moving parts – maintenance free
- Easy mounting
- Compact, rugged, easy to install
- 316 stainless steel available on special order
- Special lengths available
- Unlimited system lengths of uninterrupted airflow available
Air Knife Cooling
- Extrusion cooling, food processing, and dimensional stability control.
- Cool metal parts prior to coating and/or painting.
- Replace general manufacturing fans
- Cooling to set some inks
Air Knife Case Studies
Air Knife for Drying Cans
A company that manufactures aluminum cans contacted us with regards to a problem they were having during the packaging process. After manufacturing, the cans need to be cleaned and washed prior to shipment to their customers who then use them to package fruit and vegetables. Due to the cans not being dried properly they were seeing a lot of stress corrosion and this was causing the cans to leak. Also, the cardboard used for packaging the calls was weakened by the leftover water from the cans.
By installing two 12″ Regular Aluminum Air knife on each side of the conveyor and an additional 36″ Regular Aluminum Air Knife along the top, they were successful in stripping the water from the cans being transported down the conveyor. Using our low-cost affordable air knives our customer was able to:
Ion Air Knife for Remove Static Electricity
Although plastic bags are becoming less popular due to environmental concerns, many factories still use them to package their products. This at times, can be quite frustrating when a plastic bag refuses to unfold.
This came up recently when one of our customers ordered our Advanced Ion Air Knife due to problems they had encountered on their packaging line. Previously they were using a vacuuming system that at times would jam when picking up multiple bags that were loaded by the operator. The problem would occur when static electricity would cause the bags to hold together. This caused our customer to incur an additional cost, time and manpower to clear the jams as they occurred.
Our customer placed the order for Advanced Ion Air Knife and received it within 3 days. After a quick installation, the results were visible immediately. Now the operator can load the bags into the packaging machine using the Ion Air Knife to blow ionizing air onto the stack of bags removing the static electricity. Adding Streamtek Ion Air Knife saved our customer time in preparation of the bags then previous vacuum method as well as time and man power that was being wasted clearing jams.
Air Knife for Uniform Sheet of Air
A customer from a set in Hollywood called us on Friday evening at 6:45 pm, they were shooting a scene tomorrow afternoon (Saturday). They needed a uniform sheet of air to be projected across the front of the camera lens to protect it from the dust n’ dirt that would become airborne from the intense action scenes.
I recommended that they install our 18″ Advanced Aluminum Air Knife /w Air Filter & Pressure Regulator. The air filter was a critical component in that it would ensure a clean dry source of compressed air was projected in front of the lens! In addition, the Aluminum Air Knife operates at a much lower sound level.
Since we received the call so late in the day, we missed the cutoff time by UPS to ship the package to the customer for a reasonable rate. This wasn’t a problem though, as Streamtek works closely with all the major Couriers (UPS, FedEx, Purolator, DHL, Canpar, USPS, and Canada Post). We were able to ship the package out at 7:45 pm via FedEx at a very reasonable rate for the customer. The customer will receive the package by 10:00 am tomorrow (Saturday).
Dimensions
| DIMENSIONS: Advanced Air Knife | ||||||||
| A | B | C | D | E | F | # of rear inlets 1/4″ NPT | # of side inlets 1/4″ NPT | |
| 3″ (76 mm) | .645″ (18 mm) | 1.5″ (25 mm) | 1″ (25 mm) | 0.21″ (5 mm) | – | 0.39″ (10 mm) | 1 | 0 |
| 6″ (152 mm) | 1″ (25 mm) | 3″ (76 mm) | 1.5″ (47 mm) | 0.52″ (13.2 mm) | 1.02″ (26 mm) | 0.39″ (10 mm) | 1 | 2 |
| 8″ (203 mm) | 1″ (25 mm) | 4″ (102 mm) | 1.5″ (47 mm) | 0.52″ (13.2 mm) | 1.02″ (26 mm) | 0.39″ (10 mm) | 1 | 2 |
| 9″ (229 mm) | 1″ (25 mm) | 3″ (76 mm) | 1.5″ (47 mm) | 0.52″ (13.2 mm) | 1.02″ (26 mm) | 0.39″ (10 mm) | 2 | 2 |
| 12″ (305 mm) | 1″ (25 mm) | 3″ (76 mm) | 1.5″ (47 mm) | 0.52″ (13.2 mm) | 1.02″ (26 mm) | 0.39″ (10 mm) | 2 | 2 |
| 18″ (457 mm) | 1″ (25 mm) | 5″ (127 mm) | 1.5″ (47 mm) | 0.52″ (13.2 mm) | 1.02″ (26 mm) | 0.39″ (10 mm) | 2 | 2 |
| 24″ (610 mm) | 1″ (25 mm) | 6″ (152 mm) | 1.5″ (47 mm) | 0.52″ (13.2 mm) | 1.02″ (26 mm) | 0.39″ (10 mm) | 2 | 2 |
| 30″ (762 mm) | 1″ (25 mm) | 6″ (152 mm) | 1.5″ (47 mm) | 0.52″ (13.2 mm) | 1.02″ (26 mm) | 0.39″ (10 mm) | 2 | 2 |
| 36″ (914 mm) | 1″ (25 mm) | 6″ (152 mm) | 1.5″ (47 mm) | 0.52″ (13.2 mm) | 1.02″ (26 mm) | 0.39″ (10 mm) | 2 | 2 |
| 42″ (1067 mm) | 1″ (25 mm) | 6″ (152 mm) | 1.5″ (47 mm) | 0.52″ (13.2 mm) | 1.02″ (26 mm) | 0.39″ (10 mm) | 2 | 2 |
| 48″ (1219 mm) | 1″ (25 mm) | 9″ (229 mm) | 1.5″ (47 mm) | 0.52″ (13.2 mm) | 1.02″ (26 mm) | 0.39″ (10 mm) | 3 | 2 |
| 54″ (1372 mm) | 1″ (25 mm) | 9″ (229 mm) | 1.5″ (47 mm) | 0.52″ (13.2 mm) | 1.02″ (26 mm) | 0.39″ (10 mm) | 3 | 2 |
| DIMENSIONS: Regular Air Knife | |||||||
| A | B | C | D | E | F | # of rear inlets 1/4″ NPT | |
| 3″ (76 mm) | 0.7″ (18 mm) | – | – | 2.3″ (58 mm) | 3″ (76 mm) | 0.32″ (8 mm) | 1 |
| 6″ (152 mm) | 1.3″ (33 mm) | – | – | 4.6″ (117 mm) | 6″ (152 mm) | 0.32″ (8 mm) | 1 |
| 8″ (203 mm) | 1.3″ (33 mm) | – | – | 6.7″ (170 mm) | 8″ (203 mm) | 0.32″ (8 mm) | 1 |
| 9″ (229 mm) | 1.3″ (33 mm) | – | – | 7.3″ (185 mm) | 9″ (229 mm) | 0.32″ (8 mm) | 1 |
| 12″ (305 mm) | 1.3″ (33 mm) | 3.3″ (84 mm) | 8.7″ (221 mm) | 10.7″ (272 mm) | 12″ (305 mm) | 0.32″ (8 mm) | 1 |
| 18″ (457 mm) | 1.4″ (36 mm) | 5.9″ (150 mm) | 12.1″ (307 mm) | 16.6″ (422 mm) | 18″ (457 mm) | 0.32″ (8 mm) | 2 |
| 24″ (610 mm) | 1.4″ (36 mm) | 9.1″ (150 mm) | 14.9″ (378 mm) | 22.6″ (574 mm) | 24″ (610 mm) | 0.32″ (8 mm) | 2 |
| 30″ (762 mm) | 1.5″ (38 mm) | 9.1″ (150 mm) | 20.9″ (531 mm) | 28.5″ (724 mm) | 30″ (762 mm) | 0.32″ (8 mm) | 2 |
| 36″ (914 mm) | 1.5″ (38 mm) | 9.1″ (150 mm) | 26.9″ (683 mm) | 34.5″ (876 mm) | 36″ (914 mm) | 0.32″ (8 mm) | 2 |
| 42″ (1067 mm) | 1.5″ (38 mm) | 9.1″ (150 mm) | 32.9″ (836 mm) | 40.5″ (1029 mm) | 42″ (1067 mm) | 0.32″ (8 mm) | 2 |
| 48″ (1219 mm) | 1.5″ (38 mm) | 9.1″ (150 mm) | 38.9″ (988 mm) | 46.5″ (1181 mm) | 48″ (1219 mm) | 0.32″ (8 mm) | 3 |
| 54″ (1372 mm) | 1.5″ (38 mm) | 9.1″ (150 mm) | 44.9″ (1140 mm) | 52.5″ (1334 mm) | 54″ (1372 mm) | 0.32″ (8 mm) | 3 |
Air knife FAQs
No. The Air knife is designed to use only compressed air. Blowers are very noisy, large, and expensive with 3″ to 6″ connections. They simply will not produce enough force to operate our Air knife.
No. The Air knife is precision-machined. Cutting it would expose the internal design with no way to reseal the Air knife. With that said, custom sizes can be machined upon special request.
No. This would cause an airflow restriction which would instantly produce back-pressure in excess of 5 PSIG! When this back-pressure is exceeded, performance of the Vortex Tube will be negatively impacted. The hot end of the Vortex Tube on the other hand can withstand a pressure up to 30 PSIG (depending on the cold fraction).
Always try to use the lowest pressure that is possible for your application. Always use a pressure regulator to increase force/airflow to the point where your application problem is rectified. The maximum pressure of the Air knife is 250 PSIG.
The rigid compressed air pipe is the best way to mount the regular Air knife (a.k.a. air curtain). If this is not possible, there are multiple 1/4-20 mounting holes located on the back of the Air knife.
Yes. We have the capabilities to manufacture up to 109″ long Air knives. In addition, any length Air knife can be machined upon special request. Lead time for custom orders is typically 2-3 weeks.
Aluminum Air knife:
275°F (135°C)
Stainless Steel (Type 303) Air knife:
400°F (204°C)
Stainless Steel (Type 316) Air knife:
800°F (427°C)
* Temperatures that exceed 800ºF (427ºC) could produce inter-granular corrosion which could eventually plug the air gap opening.
Before you increase the standard gap opening of .002″, it’s important to ensure your Air knife is working properly. The low flow can be caused by a clogged filter, undersize lines, undersized air compressor, restrictive fittings or even particles clogging up the gap between the Air knife body and cap.
To verify that full line pressure is available, install a pipe-tee along with a pressure gauge at any one of the inlets of the Air knife. If full line pressure is present and additional flow is needed, turn off the compressed air supply and disassemble your Air knife. Be sure to clean the air knife body, cap and shim before reassembling with the additional shim. Tighten each screw to 7.5 ft/lbs.
Each and every Air Knife that leaves our facility is tested to ensure proper flow characteristics. We suggest that you examine the below (3) three possibilities that may cause these dead spots.
i) Inspect the Air Knife for direct contamination and/or clogging. Cleaning instructions are found in the Installation and Maintenance sheet supplied with your Air Knife.
ii) Screws may have been over tightened during reassembly or mounting. Screws should be tightened to 7.5 ft/lbs.
iii) Air knife may be undersupplied. Do not use undersized lines, filters or restrictive fittings that may not allow enough airflow into the plenum chamber of the Air Knife.
A higher force of air flow can be achieved by increasing the volume of air that’s being throttled through the Air knife. There are (2) two ways to do this:
i) Increase the supply pressure. Maximum safe level is 250 PSIG!
ii) Install additional shim(s).
** Both of the above will have a direct effect on the volume of compressed air that is required to supply your Air knife. Therefore proper plumbing modifications should be taken into consideration.
The Streamtek Air knife is not position sensitive. It is effective when pointed in any direction.
Pneumatic Air Knife Design by Streamtek
In-house facilities and solutions that help in developing better outcomes and results
With our Air Knives or any other products that we sell you will get faster return on investment
High-tech methodology blends with expertise to increase availability and reliability of products
Well-defined engineering and project management processes save costs and time
