| 摘要 |
1420765 Pneumatic discharge of hoppers CLAUDIUS PETERS AG 29 Dec 1972 [30 Dec 1971] 60170/72 Heading B8A [Also in Division F2] The outlet of a container is controlled by a cylindrical or spherical closure member 6 which slidingly co-operates with a sealing arrangement comprising a pair of rigid rings 19, 20 sandwiching resilient rings 22, 23, the ring 22 engaging the closure member 6 with a pressure dependent on the pressure of fluid admitted to an annular closed space 24 defined by the ring 20, 23, this fluid pressure being controlled by a valve 14 to reduce the sealing pressure during movement of the closure member. To detect wear of the ring 22, either an electrical insert is embedded in the ring 22 or a cavity is formed in the ring 22. In the former case either the conductivity of the insert or the resistance between the insert and the closure member 6 is measured. In the latter case the integrity of the cavity is checked. The valve 14 is situated in a line which branches from a line carrying air to a nozzle 9 at the inlet 8 of a pneumatic conveyer. |
