Steam turbine shaft sealing mechanism - has condensate acting as barrier fluid acting against floating ring in housing

摘要

The shaft seal is for a steam turbine connected to a condenser. A floating sealing ring (5) is mounted in an opening in the housing (2) through which the shaft passes (1). There are inlet and outlet passages (3, 7, 8) for condensate, acting as a barrier fluid against the ring. An annular body (9) is mounted on the shaft, and the inlet and outlet passages are connected to the condenser. The body can comprise a number of annular segments, and in the inlet passage there can be a main pump, with an auxiliary one connected in parallel with it by means of a bypass pipe. There can be axial gaps between the annular segments, and body and sealing ring can be of different materials.