Patent ID: 8647052
Filing Date: 2014-02-11
Classification: F16J

Abstract:
1. A shaft seal for sealing a gap of a penetration of a shaft through a casing, wherein in an interior of the casing there is a process fluid under a sealing pressure and outside the casing there is an ambient fluid under an ambient pressure, the shaft seal comprising: a fluid feed; a fluid drain; and a plurality of sealing modules, wherein, between the sealing modules, a provision is made for the fluid drain via which a first drain fluid is discharged, the plurality of sealing modules comprising at least a first main seal, wherein the ambient pressure differs from the sealing pressure in an operating state of the shaft seal by a pressure difference, which pressure difference, divided up to form proportions, is applied to each of the plurality of sealing modules in each case as a partial pressure difference, wherein a largest partial pressure difference of the partial pressure differences is applied to the first main seal, and wherein the first main seal is a radial double seal defined by a first gas seal and a second gas seal, each of the first gas seal and the second gas seal comprising: wherein between the sealing surface pair of the first gas seal and that of the second gas seal, a circumferentially extending sealing fluid chamber is provided which is exposed to an admission of sealing fluid via a sealing fluid feed.