3 replies to this topic

[luuquocdai]

Dear
I am calculating a compressor of recycle gas flow (mix of H2 and other components).
I have a problem which I can't understand.
When we calculate Centrifugal pump, we have to take care about Static Head on Pump Discharge, it is based on the elevation from the last point in the discharge of pump to the pump suction centerline (follow Bernoulli Equation)
But in Centrifugal Compressor, we don't take care about this value.
Why we have the difference between Compressor and Pump in this calculation.
Please help me to answer this question.
Many thanks.
luuquocdai
Email: luuquocdai@gmail.com

[NGL Licensor]

Hi,

Simply because liquids are not compressible.

In the case of compressed gases, the elevation difference will not create a static head because of the low density compared to liquids

A.King

[ankur2061]

luuquocdai,

I think you need to go back to your basics of 'physical chemistry' and understand the gas laws.

Essentially the fact that a gas will occupy all the volume of any system containing it and pressure in a fixed volume will also change if there is change in temperature based on Gay-Lussac's law.

Thus the concept of static head or gas column is not really applicable for gases.

Hope this clears some of your doubts.

Regards,
Ankur.

[luuquocdai]

Dear Ankur2061 and NGL Licensor
Many thanks for your answer.