CROSSHEAD TYPE COMPRESSOR

[swarthy]

Explain why only the crosshead type compressor is used for process service

From the attachment why does the gas enters at the top and the coolant enters at the bottom

is this attachment a suction or a discharge valve?

 

[JJPellin]

A reciprocating compressor is used for services where a high compression ratio is rehired. Process gas enters at the top and exits at the bottom so that any liquid that forms will be drained away and not accumulate.

Johnny Pellin

 

[JJPellin]

The coolant enters at the bottom and exits at the top so that the cooling jacket will completely flooded with no trapped vapor pocket. The image you attached is a valve. These serve as check valves on the inlet and outlet of each cylinder.

Johnny Pellin

 

[JJPellin]

It is not possible to tell from this image if it is a suction or a discharge valve.

Johnny Pellin

 

[Compositepro]

A crosshead type compressor isolates the crankcase of the compressor from the process gas.
I would say the picture is of a suction valve because it would be a bad idea to place a nut on a bolt in side the compression cylinder.

 

[zdas04]

Let's try again. The rod that connects to the crank moves a considerable distance laterally as the crank rotates from 0° crank angle to 180° crank angle. Sealing around this eccentric movement at high compression ratios is not possible. so the crosshead makes double acting cylinders possible. The crank connecting-rod connects the crank to the crosshead which is constrained to move in a linear manner. The piston rod can now be a cross section that can be sealed so that you can create a compression chamber on the crank end of the piston. The crosshead does not seal the process gas from the crankcase.

David Simpson, PE
MuleShoe Engineering

Law is the common force organized to act as an obstacle of injustice Frédéric Bastiat