| 摘要 |
441,641. Filters. BLOMFIELD ENGINEERING CO., Ltd., Blomfield Street, New Broad Street, London, and DURANT, H. T., Kesters, Crawley, Sussex. Aug. 31, 1934, No. 25158. [Class 46] The stationary part of the distributing valve of a rotary suction filter has two compartments, each connected to its own vacuum pump and co-operating respectively in the formation and drying of the cake, and a third compartment through which water is supplied to wash the filter cloth after removal of the cake, and an extra pipe connection is provided from each filter section to the moving part of the valve to permit rapid displacement of air from the element by the water. Fig. 6 shows the stationary part 15 of the valve with vacuum compartments 14, 20, back-wash water compartment 26 and air vents 28, 27. The moving part 9, Fig. 5, of the valve has an outer series of ports 24 and an inner series 25, each filter element being connected to one of each series by pipes 8. Both series register successively with the compartments 14, 20 and the air vent 28, but while an outer port is registering with the compartment 26 the corresponding inner port is registering with the vent 27. The part 15 is pressed against the part 9 by a thrust ball race and a bell-crank lever with counterweight. The filtrate is withdrawn from the compartments 14, 20 through pipes 12, 16, Fig. 2, respectively by pumps 10 which deliver it to a tank 17, from which wash water is supplied to the compartment 26 through a pipe 34. The filter elements may be expansible to assist in loosening the cake and may be formed of layers of filter canvas, coconut matting, perforated steel plate, and sponge rubber or other resilient material. The cake may be removed by a driven roller 29 held against the drum by a spring or counterweight. |
