Bare Shaft Positive Displacement Blowers

At its most basic level a blower is a machine that draws in air at an inlet and pushes air out as a steady stream at the outlet. There are largely two categories of blowers: impeller based and positive displacement. 

Impeller based blowers have fins that radiate outwards from a rotating central axis. 

Positive displacement blowers use a mechanism of filling and emptying chambers at the inlet and discharge side, respectively, to create air flow. 

The fundamental difference between the two is that impeller based blowers have output flow that varies with pressure whereas positive displacement blowers have a more constant output flow regardless of change in pressure.

The impeller is generally called rotors or lobes.

There is no compressed air during the running of the positive displacement rotary lobe blowers.

Bare Shaft Positive Blowers are suitable for pressure or vacuum operation (negative pressures). 

The blowers are suitable for pumping/compressing ambient air and no-flammable gases, gas mixtures, neutral gases and dusts.

They are often used for pneumatic conveying, aeration in wastewater treatment, fluidisation, filter cleaning. They can also be used directly on trucks for dry-bulk transfer.