Centrifugal compressor running on lighter gas than design

[nRGee]

Dear All,

What happens when a centrifugal compressor equipped with anti-surge valve is run on lighter gas than design?
(Design MW of gas= 22, Actual MW of gas=13)?

Does it leads to surge?

Thanks and Best regards,
Raghu N

 

[1503-44]

I haven't tried that, but pretty sure that's a yes. Much less density, so it's similar to reducing inlet pressure by half.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[MJCronin]

What does it say in the Owner's Manual and Vendor Documentation ? ... You can typically find limits to operation there...

Is this a repurposed compressor ? .... How much "lighter" is the new gas ?

More information please ...

What do you mean that it has been lost/discarded by the Plant Staff

MJCronin
Sr. Process Engineer

 

[1503-44]

13/22=59% , implies around 41% lighter. I think that's gotta be off the chart.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[pmover]

read the attached and evaluate yourself.

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1687449728/tips/How_to_use_the_performance_curves_to_evalute_behavior_lu3rwz.pdf[/url]

 

[georgeverghese]

To get the same discharge pressure, the compressor will have to go higher up on the head - flow curve with a lighter gas.
How does your ASV work, on discharge pressure only, or on simple differential pressure( discharge - suction), or on mol wt / density compensated flow control?