Industrial centrifugal blower fans - inlet guide vanes

The INLET VANES are the valves most used to control flow and pressure in all kind of installations involving centrifugal fans.

Valves of this type are fitted at the air intake of the fan and comprise a series of radial vanes that turn together. Operating the valve provides an air swirl that will immediately affect the power consumption of the fan.











The valve creates a PRE-ROTATION of the incoming flow in the direction of the fan rotation, which means a reduction of the work performed on the air, diminishing in this way the difference between the impeller speed and the speed of the gas.

Since the presence of the valve also entails a pressure loss to get the air PRE-ROTATION, the resulting performance curve with the valve partially closed is located between the performance curve corresponding to a motor speed reduction and the curve that represents pressure loss increasing with flow.