hi all, here is a basic questio

[saidsaz]

hi all,

here is a basic question that has been a source of confusion ,,let me start discusion for those interested ( and know correct answers) by these two qustions ,,

i always thought that for a constant speed compressor :

1- for any change in suction properties like pressure ,mw ,T SUCTION VOLUME FLOW WILL REMAIN CONSTANT,but power will change propotional to mass flow? is this correct ?

2- in case of throtting suction or discharge volume flow will change(decrease ) cause head will change (increased) as compressor will back up on its curve ? is this correct ?

thnx in advance

 

Both your answers appear to be correct, at least to me.

The extent of variation will however depend on whether the compressor is a centrifugal or a positive displacement machine.

http://business.vsnl.com/chemical/chemprocesshpage.html

 

[burt1]

Good Day

To answer in some part your question, Depending on the amount of variation, the volumetric flow from the machine can change, this is due to the volumetric effeciency of the machine varying ( mostly on Recep compressors and to some extent Centri ). If you throttel the suction to much and keep the discharge pressure constant there will be a large increase in temp of the discharged gas.


Regards