What is the Standard Air Knife?
A quiet, energy efficient way to clean, dry or cool parts, webs or conveyors. The Standard Air Knife utilizes the coanda effect (wall attachment of a high velocity fluid) to create air motion in its surroundings. Using a small amount of compressed air as a power source, the Standard Air Knife pulls in large volumes of surrounding air to produce a high flow, high velocity curtain of air for blowoff.
Amplification ratios (entrained air to compressed air) of 30:1 are achieved with the Standard Air Knife, compared to 3:1 for drilled or slotted pipe. Air savings of 40% to 90% are possible when replacing these “homemade” blowoff devices. Pay-back is normally measured in weeks, not months or years.
The Standard Air Knife dramatically reduces “wind shear” by gradually introducing the entrained air to the ejected compressed air. Noise level is typically cut in half. The result is a high velocity, high volume sheet of air with reduced noise level and air consumption.
Drilled pipe or open jets, by contrast, provide minimal air amplification. They also produce unacceptably high noise levels as the compressed air shears into the still air.
How the Standard Air Knife works
Compressed air flows through the inlet (1) into a plenum chamber. It is then throttled through a thin nozzle (2) extending the length of the Standard Air Knife. This primary airstream adheres to the coanda profile (3), which turns it 90° and directs the flow down the face of the unit. The primary stream immediately begins to entrain surrounding air (4), for an amplification ratio of 30;1 at 6″ (152mm) away.
Applications
Part drying after wash
Sheet cleaning in strip mills
Conveyor cleaning
Part or component cooling
Web drying or cleaning
Environmental separation
Bag opening/fill operations
Pre-paint blowoff
Scrap removal on converting operations
Advantages
Up to 10 dBA noise reduction
Reduced air consumption
30:1 air amplification
Aluminum or stainless steel
Variable force and flow
Stock lengths to 48″ (1219mm)
Unlimited system lengths
No moving parts
Compact, rugged, easy to install
Performance
Air Flow Pattern Performance
Standard Air Knife Performance with .002″ (0.05mm) shim installed.
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
Ozs
Grams
20
1.4
1.3
37
4,000
20.3
65
0.45
13
40
2.8
2.0
57
5,800
29.5
74
1.1
31
60
4.1
2.7
76
8,500
43.2
80
2.0
57
80
5.5
3.4
96
11,000
55.9
83
2.7
77
100
6.9
4.1
116
13,000
66.0
86
3.3
94
12″ (305mm) Standard Air Knife Tested. Note: Performance on lengths over 36″ will vary.
A Standard Air Knife has a .002″ (0.05mm) gap setting. This gap is set with a shim positioned between the cap and body of the Standard Air Knife. Force and flow through the Standard Air Knife may be easily increased by adding shims to open the gap. Standard Air Knife Kits include a shim set (three additional shims). Shim sets for aluminum Standard Air Knives include a .001″ (0.03mm), .003″ (0.08mm) and .004″ (0.10mm) thick plastic shim. Shim sets for stainless steel Standard Air Knives include (3) .002″ (0.05mm) thick stainless steel shims.
Accessories
Model
Description
9076
Air Knife Plumbing Kit for Standard Air Knives size 24″-42″
9077
Air Knife Plumbing Kit for Standard Air Knives size 28″-54″
9060
Universal Air Knife Mounting System
900517
Universal Air Knife Mounting System Stainless Steel 303/304
EXAIR’s EFC is an electronic flow control that dramatically reduces compressed air costs by turning off the compressed air when no part is present. This minimizes compressed air use for blow off, drying, cooling, conveying and static elimination operations. The EFC combines a photoelectric sensor with a timing control that limits compressed air use by turning it off when no part is present.
