What is an air knife?

An air knife uses compressed air to create a curtain-like air flow. Inside the air knife is a long narrow chamber in which the air is squeezed and forced out through a narrow slot the same width as the chamber. The result is an even air flow over the entire width of the blade, an air curtain.

An air knife uses the 'Coanda' effect

This is the tendency for a liquid or gas stream to follow a convex surface rather than a straight line in the original direction. This effect is named after the pioneer of aerodynamics Henri Coanda. The Coanda effect is the same principle that causes a water jet to follow the same curvature along a round object. Or that increases the lift force (air along the wing) of an aircraft wing so that the aircraft can fly.

The compressed air supplied into an air knife is forced to pass through a reduced opening, from 0.02 mm to 0.08 mm. In the vicinity, the surrounding air is drawn in the direction of the flow, so that the air volume at the blow-out becomes 5 to 20 times greater than at the inlet.

When to use an air knife?

As explained above, air knives create a high blowing force, 5 to 20 times greater than the inlet pressure. This wide, uniform airflow is very effective for cleaning, drying or cooling, for example. Some possible applications are:

Cooling products or liquids
Drying of products
Removing dust, dirt, oil or excess liquid
Removing products by means of an air blast
Printing and labeling
Packing
Lamination
Shapes and fill
Sheet and web materials
Opening / filling of bags
Transport
Food processing
Paint preparation
Etc.

Do you have questions?
Please contact us. We are happy to help!

or call +31 (0)493 763993

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