4 replies to this topic

[chemproc]

Would  anyone recommend using a control valve on compressor discharge?

 

We are currently in the design phase and are considering going with either screw or centrifugal compressor

 

See attached PFD.

[chemproc]

The PFD is attached.

Attached Files

•  comp discgarge.JPG   47.37KB   6 downloads

[thorium90]

If its centrifugal, then a discharge control valve is fine. If its screw, then no.

I think the first thing should be to choose the type of compressor, centrifugal or screw. 

Normally flow and pressure requirement is a major deciding factor for the choice. 

High flow lower pressure can be centrifugal.

Low flow higher pressure can be screw.

After you make the choice of type, then you can start thinking about how to control the compressor.

 

Perhaps you can share (in writing or another picture) what are the flows and pressure you require. Because your picture is too blurry to tell.....

Edited by thorium90, 26 May 2019 - 10:21 PM.

[Chemitofreak]

Thorium is correct...!

 

First finalise the compressor, then finalise its controls.

[oilpmp]

Hi, I would add that in case of centrifugal compressor typology is selected, this can be done but one has to keep in mind that throttling the pressure at the compressor discharge for purpose of process regulation, is generally a very costly method in terms of energy waste, when compared to suction pressure throttling (most common) or speed variation. Not sure about the implications in terms of start up torque if the driver is fixed speed, maybe a point to investigate.