| 摘要 |
478,887. Filters. CAMPBELL, R. C. July 27, 1936, No. 20712. [Class 46] In a sectionalized rotary vacuum filter having separate passages for the discharge of filtrate from the several sections, the valve which controls the passages is arranged so that there is a small clearance at the ends of the passages. As shown in Fig. 1, the passages 10 terminate in an annular surface 11 and filtrate is discharged from the interior of the drum through the trunnion 3. A plate valve or shoe 13 co-operates with the surface 11 to close the passages corresponding to the sections from which the cake is being detached. The valve member 13 is supported from a shaft 15 which can be adjusted longitudinally to give the desired clearance between the part 13 and the surface 11 by means of a bracket 21, which screws on the trunnion 2 and engages a thrust bearing 22. Rotation of the shaft 15 is prevented by a counterweight 18 or by an arm 19, the outer end of which can be fixed. The shaft 15 and arm 14 may be made hollow for the supply of air to assist in cleaning the filtering medium. Fig. 3 shows a form of apparatus in which the filtrate is discharged from the sections through separate passages 25 in the end wall of the drum, the hollow trunnion 33 and a fixed right-angle bend 36. The passages 25 corresponding to the sections from which cake is being detached are closed by a frusto-conical valve member 29 carried by a shaft 32 passing through a sleeve 42, which rotates with the trunnion. Longitudinal adjustment of the shaft to give the desired clearance at the valve member is obtained by means of a nut 45 which has an inner flange 46 engaging thrust bearings 47, 48 between rings 49, 50 fixed to the shaft. Rotation of the shaft is prevented by means of an arm 41. A further modification is shown in Fig. 7. The passages 58 from the sections discharge the filtrate into the interior of the drum from which it passes away through the trunnion which is not shown. A valve plate 62 to close the passages corresponding to the sections from which cake is being detached is carried by a pipe 57 passing through the trunnion 54. The pipe also carries a hopper 63 into which wash-water is collected from sections passing under wash-water supply jets for discharge through the pipe 57. The pipe 57 can be moved longitudinally to adjust the clearance of the valve plate by means of a nut 64 with inner flange engaging thrust bearings 67, 68. Rotation of pipe 57 is prevented by an arm 71. |
