Centrifugal Blower

Centrifugal Blower

An impeller is attached to a rotating shaft within a cylindrical housing.

Gas drawn into the housing near the centre, is then thrown towards the perimeter.

The imparted velocity of the gas causes a pressure rise and flow.

Multi-stage machines direct the gas back to the centre of the next stage.

Typical Performance Envelope
Imperial Metric
Minimum swept volume 100 cfm 170 m3/h
Maximum swept flow 40,000 cfm 70,000 m3/h
Maximum casing pressure 30 psi 2 bar
Maximum pressure ratio 2.2
Advantages
  • Slow speed of rotation gives exceptional wear part life.
  • Single rotor is only moving part.
  • Oil free gas path.
  • Vibration free operation.
  • Flow control through inlet throttling and speed control.
  • No special foundation required, lowering civil costs.
  • Can usually be direct driven – doing away with belts or gearboxes.
  • Pulsation free gas discharge.
  • Valveless porting means no drop off in efficiency between overhauls, and no valves to maintain or break in service.
  • Simplicity: units are readily overhauled in the field without special tools.
  • Efficiency is good on the larger flow machines.
  • Quiet operation – often no sound attenuation is required.
Disadvantages
  • Lower efficiency on smaller flows.
  • Higher capital cost on positive displacement blowers.
  • Low maximum casing pressure.
Common Applications
  • Landfill gas gathering and boosting.
  • Waste water aeration.
  • Steel works gases.