Major types are centrifugal blower and positive-displacement blower.
Centrifugal blowers look more like centrifugal pumps than fans. The impeller is typically gear-driven and rotates as fast as 2900 rpm. In multi-stage blowers, air is accelerated as it passes through each impeller.
In single-stage blower, air does not take many turns, and hence it is more efficient. Centrifugal blowers can achieve higher pressures up to 1500 mmWC
Types, characteristics and applications id of centrifugal blower
Type |
Characteristics |
Application |
Radial |
High pressure, medium flow, efficiency close to tube-axial fans, power increases continuously |
Various industrial Application Suitable for dust laden, moist air /gas |
Forward curved blades |
Medium Pressure, High Flow, dip in pressure curve, efficiency higher than Radial fans , power rises continuously |
Low Pressure HVAC package units, suitable for clean and dust laden air/ gases |
Backward Curved Blades |
High pressure, high flow, high efficiency, power reduces as flow increases beyond point of highest efficiency |
HVAC, various industrial applications forced draft fans. |
Airfoil type |
Same as backward curved, highest efficiency |
Same as backward curved but for clean air applications. |