Device for circulating sealing gas for mechanical dry seals of a centrifugal compressor at times when the machine is stationary and pressurized

摘要

A device ( 10 ) for circulating sealing gas for mechanical dry seals ( 11 ) of a centrifugal compressor ( 13 ) at times when the machine is stationary and pressurized; the device comprises a sealed reciprocating compressor ( 12 ), which includes a piston ( 14 ) slidable in a cylinder ( 16 ), and the piston ( 14 ) is moved by a magnetic coupling to an external magnetic element ( 20 ) which moves along the said cylinder ( 16 ).