reciprocating compressors in paralel

[adelnaftec]

Hi
Please I need help,
What is the conditions operate 02 reciprocating compressors in parallel (the both compressors are same)
Thanks.

 

[LittleInch]

You need double the flow rate of one of them??

No details or data so difficult to provide an answer

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[adelnaftec]

Thank you LittleInch
We have 02 reciprocation compressors (data by compressor: Q=8000 Nm3/h, discharge pressure 406 Psi) in our case one compresor march 50% to 75% , the second is stand-by.
Now we need install the third compressor (same data).
New operating conditions: 02 compressors march and 01 stand-by, so how to use the both compressors in paralle.
Thanks

 

[LittleInch]

Still a bit confused

"O2" - Do you mean two or Oxygen?
"march 50% to 75%" - sorry don't understand what this means - do you mean it only operates at 50 to 75% of capacity??
"Now we need install the third compressor (same data)." - Why if one compressor is not at full capacity?

So long as the three machines see the same suction pressure and have the same compression ratio, and are fixed speed, then they should share duty equally.

I'm really not sure what your concern or problem is and suspect you are only giving us 10% of the information.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[zdas04]

My experience is that this is not as trivial as you would hope. No two piping configurations are ever exactly equal, so I find that a bank of "identical" machines all behind one suction controller will tend to have very uneven loading. I've fixed this by doing suction control in two stages. For example if the design suction for the header is 100 psig, then I will put a site inlet controller to maintain 125 psig into the header, and then take the last cut on each compressor. This shouldn't make much difference, bu I find that I get much more stable control this way.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist