Centrifugal Fan in Boiler Application

While we design Centrifugal Fan as ID Fan for boiler flue gas,

...Assuming the Impeller to be Drum type Impeller (ie., Impeller Width is Constant).

A. Which type of blade should be used, ie., either BackWard Swept or Forward Swept or Radially Tipped.

B. What are the optimum inlet and exit blade angles.

C. Design procedures for Volute Casing for the blower.

Provide your valuable resources in ID Fan design for boiler.

with Thanks
LRamu

 

[Narasimha]

Generally ID fans are backward swept to reduce erosion of blades.

 

[SPLIT]

Aerofoil backwards blades IDF,have the higher efficiency, and a self limited power.Backwards curved blades IDF are in second place as efficiency.But if you have much suspended solids in the flue gases, you should choose radial blades , because they are self cleaning blades