Seal for hollow shaft in pressure disk filter housing

摘要

In the pressure disk pilter of the parent patent, between the sealing face of the accordion-type bellows on the hollow shaft and the sealing face of the housing sediments collect so that the seal becomes faulty and the filtrate is contaminated.This is overcome in this addn. by providing the bellows with a pressure ring having >=1 drilling which may be inclined to the sealing faces. During periods of reduced pressure, fluid escapes through the bores and cleans the sealing surfaces. When pressure rises again, the bellows extends and the ring is pressed correctly into position.