SEAL PRIMARILY FOR A TURBINE

摘要

A pressure seal is provided as an alternative to the normal gland or labyrinth seal between two relatively rotatable members 10, 11. In this seal an annular jet of seal fluid is directed from a first duct 15 defined in one of the members 10, 11 towards the other member so as to form a moving curtain of seal fluid therebetween, and means 19 is provided for forming an annular mass of seal fluid on the higher pressure side of the moving curtain whereby to prevent entrainment of fluid from the region 12 which adjoins the higher pressure side into the moving curtain and thence into the region 13 adjoining the lower pressure side. A second duct 20 may be defined within the one member 11 for the purpose of forming a further moving curtain of seal fluid between the annular mass and the higher pressure region 12. The second duct 18 may be fed from the same pressure source as the first, suitable throttling means 21 being interposed between the two.