Centrifugal Compressor Vs Blower ?

If we see construction wise, blowers are robust ones with higher impeller diameters and speed rarely exceeding 3000 rpm, so they are direct driven without any gearbox for increasing speed. In case of centrifugal compressors, impellers are smaller in diameter but rotate at very high speed (with the help of gearbox) to attain higher tip velocity for higher pressure ratio. Its seals are more sophisticated to suit higher pressure differential between stages.

Here, I want to differentiate among fan, blower and compressor, application wise also as follows:

Fans: To displace the required quantum of gas from one location to other. Pressure at the end point is not the issue.

Blower: To displace the required quantum of gas from one location to other. Pressure at the end point is just enough to blow something off.

Compressor: To displace the required quantum of gas from one location to other. Pressure at the end point is as per the process requirement.

Discharge pressure of either of the above machines depend on suction pressure and the pressure required at the end point to take care pressure drops. This classification is based on my own opinion, so I invite experts to comment on it.

No comment on Explanation given in # 1 but to distinguish three different type of equipment there must be a measurable range.

Reference Perry Handbook :

Fans are used for delivery pressure less than 0.5 lb/in2 (3.447 kPa) ,

compressor are used to increase pressure upto several hundred kPa (lb/in2 ).

Blower comes in-between pressure range of fans & blower.

Its easy to distinguish them from common sense. You just check the discharge side, when there is a considerable decrease of the discharge cross section than the intake, then that could be a blower, much lesser discharge side cross section would be a compressor. When there is no restriction of discharge cross section then that is definitely, a blower or fan.

I'd add that for centrifugal types, for a greater pressure difference, the proportions tend to have smaller inlets and outlets, relative to the length of the air path within the impeller.