axila and centrifugal blowers

[shipvibration]

1.given a particular volume what are the factors to be considered for installing an axial flow blower or a c/fugal blower?
2. where exactly are axial flow fans used and why?
3. which application are c/fugal blowers used and why?
4. what is the difference in design considerations of a centrifugal compressor and centrifugal p/p(apart from the assumption that air is incompressible for pumping)in particular, the vane geometry?
thanx.

 

[butelja]

Random thoughts and rules of thumb regarding axial vs. centrifugal follow.

In general, axial flow machines are for higher volume and lower pressure applications. Centrifugal are for lower volume higher pressure applications. The exception is multi-stage axial flow compressors ala jet engines, which are both high volume and high pressure.

Centrifugal machines are cheaper to manufacture because of the simpler geometry and reduced number of components. The adverse pressure gradient in the impeller of a centrifugal tends to lead to flow separation and efficiency losses. A properly designed axial flow machine will be more efficient than a centrifugal machine, provided the flow rate is "large", as it is not feasible to have tight enough internal clearances for efficient low volume multi stage axial compressors.