| 摘要 |
1,146,170. Travelling band filter. MASCHINENFABRIK SACK G.m.b.H. 2 Dec, 1966 [4 Dec., 1965], No. 54028/66. Heading B1D A travelling band filter, in which a paper filter web is supported or a perforate screen 10 between upper delivery chamber 11 and lower filt rate chamber 12, comprises a series of electrically controlled hydraulic or pneumatic means whereby, on clogging of the web resulting in re duced pressure in chamber 12, the dirty liquid supply valve 7 is closed compressed air is delivered by valve 43 to chamber 11 to empty it through the filter web. the pressure in chambers 11, 12 is relieved by valves 45, 47, end covers 27, 28 which clamp the web against screen 10 and close the web entry and exit slots are lifted and motor 49 is actuated to move a clean section of web into place. Vacuum meter 48 initiates the closing of valve 7 and opening of valves 43, and valves 45, 47 and end covers 27, 28 are operated after a time delay. Motor 49 is controlled by a limit switch 48 to move when cover 27 is open. Closure of the covers, cover 28 closing first to prevent tensioning of the web, initiates closure of valves 45, 47, by switch 48, and opening of valve 7. Pump 23 which empties chamber 12 is controlled by a float 25 and has an outlet throttle valve 24 which is float controlled to maintain a head of liquid in chamber 12, but pumps 4, 23 may be of centrifugal-type and run continuously. A limit switch 19 may switch off the whole plant when the supply roll 16 of filter web is exhausted. |
