How Air Knives Work

Air Knives are an integral part of Air Knife Systems. Highly effective for cleaning, drying, blow-off and liquid control for a wide range of industrial applications, Air Knife Systems are optimised to ensure maximum effectiveness at minimum running costs.

What are Air Knives?

Air Knives are an integral part of Air Knife Systems. Highly effective for cleaning, drying, blow-off and liquid control for a wide range of industrial applications, Air Knives are designed to ensure a perfectly optimised air flow for a range of industrial applications.

Air Knife Systems overall provide maximum effectiveness at minimum running costs when compared to compressed air systems as a comparison.

The effectiveness of Air Knives is achieved through precision engineering and design - Air Knives are engineered to produce a curtain-like flow of air that not only covers the full shape of an object, but acts as a barrier to foreign matter as well.

Typical Air Knife System

Industrial Air Knives

An industrial Air Knife is a pressurized air plenum chamber with a continuous slot through which pressurized air exits in a laminar (uniform) flow pattern. The exit air velocity creates an impact air velocity onto the surface of products that the air is directed toward.

Unique shape

Air Knives most commonly consist of a structure, usually made from aluminium, steel or plastic, that houses a plenum chamber and includes a unique shape on one side, formed from two blades joined together, in the shape of a knife-edge.

The success of Air Knives comes from their ability to produce the highest force/air consumption ratio.

Air Knives are able to perform cleaning, drying and blow-off functions by emitting a powerful and consistent stream of air. This is achieved through the series of slots that each Air Knife has along its “knife edge”.

The slots on Air Knives are adjustable. This means that they can be modified to allow more or less air to pass through them, through modification of their width, therefore enabling a single Air Knife system to successfully process a wide range of objects in different shapes and sizes. As well as this, the customisable nature of the air flow means users can ensure maximum power and air efficiency.

SolvAir Air Knives come with various inlet and mounting configurations, making them suitable for all applications.

Plenum Chambers

Air Knives incorporate a pressurised container that houses air at a positive pressure - the plenum chamber.

The benefit of the plenum chamber is that it equalises pressure, meaning air can be ejected at an even distribution.

Laminar Air Flow

The success of Air Knives comes from their ability to produce a particular type of air flow. This design means that when air is ejected through the Air Knife slots, it forms a laminar air flow (that also displays the Coandă effect).

Laminar air flow is a unique and useful type of air movement. It occurs when air moves at the same speed and in the same direction, with no crossover. It is a highly effective barrier, and is used for example on research facilities where a sterile environment needs to be maintained.

The Coanda Effect

The Coandă effect is the phenomena where a fluid jet attaches itself to the surface, and stays attached even if the surface curves away from the source of the jet. It is the phenomena which has contributed to the understanding of how an aircraft wing can produce lift.

Air Knives therefore use both laminar flow and the Coandă effect to create an air flow that follows the lines of the objects that pass through it.


Even Distribution

The laminar air flow generated by Air Knives is created through the inclusion of a plenum chamber at its core. The plenum chamber is located within the body of the Air Knife, and acts as a pressurised container to house the air that is generated by the blower. The plenum chamber equalises pressure, therefore ensuring even distribution, and therefore laminar air flow, when the air is ejected.

Effective Barriers to Contamination

As the air flow created by an Air Knife is powerful, smooth and uniform, it is ideal for cleaning and drying a wide range of applications within the manufacturing industry. As well as this, by adhering to an object across its shape, the Air Knives also create barriers for objects, eliminating contamination and ensuring the final product is protected, clean and of the highest finish.

Anti Static

With SolvAir Air Knives, electrical currents from anti-static bars can also be injected into the exit air knife stream to neutralize the static electricity charge on some surfaces.

Types of Air Devices

Air Knife Systems are available with a variety of Air Knives, depending on how the System is required to operate, for example:

Alumunium Air Knives

Extruded Aluminium Air Knives are suitable for a wide range of industrial environments, providing ‘precision’ air flows, as well as a long life-span.

Used mainly in drying processes, these have adjustable slot widths for optimum power and diffusion.

More about Alumunium Air Knives

Stainless Steel Air Knives

Stainless Steel Air Knives are suitable for tough industrial environments and provide high-quality performance in corrosive and/or sanitary environments.

Constructed from FDA Compliant 304 Stainless Steel they are ideal for Food, beverage and pharmaceutical industry applications.

More about Stainless Steel Knives

Circular Air Knives

Suitable for varied applications, such as cable or tube drying and plastics or rubber extrusion lines, where they effectively remove water after cooling baths.

Fully controllable 360° adjustable performance ensures no dead spots, and is particularly beneficial when processing circular products and complex extruded profiles.

More about Circular Air Knives

Cone Manifolds

Cone Manifolds provide multiple air stream outlets and are ideal for product lines that include objects across a range of sizes and shapes.

Nozzle Manifolds maintain thrust as far away as 46 cm and are ideal for applications that require a greater distance between the air source and the surface to be dried or blown off.

More about Cone Manifolds

Spyder Manifolds

Spyder Manifolds come in various sizes and combine inline nozzles with “spider-like” arms that can flex to any position, allowing for the air streams to access hard to reach places.

Our Syder Manifolds can be custom built as needed, ensuring the flexi arms are sized and spaced as required.

More about Spyder Manifolds

Air Nozzles (SV10)

Used to control the rate of air flow, speed, direction and shape of the ejected air. These are the smallest air amplifiers available.

Our SV10 Air Nozzles and Manifolds are fully-adjustable round nozzles that can be locked into the desired position on a manifold, proving a good working range.

More about SV10 Air Nozzle

Free Air Knife System - Onsite Testing

For a 100% free no-obligation consultation please contact us.

If you would like us to test, and demonstrate how an Air Knife works for your use-case and specific product - improving productivity and reducing your operating costs, please contact us.

Our team of specialists will contact you within 24 hours to discuss your requirements and arrange your full in-depth consultation free of charge.

Call: +44(0) 1473 320 307

What are Air Knife Systems?

Air Knife Systems use a precision-engineered linear slot to direct and utilise high-velocity air from a centrifugal blower.

What are Air Knife Systems used for?

Air Knives are amazingly versatile and are used for a wide variety of applications in manufacturing, such as:

  • Drying and removing liquid films from surfaces
  • Controlling surface coating
  • Blowing off dust and debris
  • Conveying, holding down or cushioning materials with air
  • Cooling/heating materials
  • Providing air curtains/barriers