Patent ID: 6607348
Filing Date: 2003-08-19
Classification: F04D

Abstract:
A gas compressor having a main housing (3), a main shaft (2) extending through said housing at one end thereof, a low pressure gas inlet (4), a high pressure gas outlet (6), and inboard and outboard tandem gas seals (12, 13) for the main shaft at said one end of the compressor housing, said inboard gas seal having an inlet (12a) connected to receive a sealing pressure (SP) maintained by the delivery pressure of the compressor, characterized by means (25, 26, 30) operative, when the gas compressor is temporarily stopped and its inlet and outlet pressure are equalized, to provide a residual delivery gas pressure (SOP), to connect an inlet (13a) of said outboard gas seal to receive the residual delivery gas pressure and to reduce the pressure of a mixture of the gases that have passed through the inboard and outboard seals (12, 13) and further characterized by heating means (28) for raising the temperature of the gas flow, produced by said residual delivery gas pressure, to the outboard gas seal (13), to prevent formation of condensate or freezing in the inboard and outboard gas seals (12, 13).