| 摘要 |
912,148. Filters; gravity-separation apparatus STAMICARBON N. V. May, 9, 1960 [May, 8, 1959], No. 16345/60. Class 46. Dilute slurry (e.g. of coal) is fed into at least one settling cone 2 whence thickened slurry passes through a valve 4 regulated by a control 6 to maintain constant the level in the feed tank 5 into which the thickend slurry falls. The slurry is pumped (8) to at least one froth flotation machine 9 whence coal concentrate is passed to a collecting tank 10 from which it passes through a level-controlled valve 12 to the troughs 19 of a number of drum filters 13. When the level in tank 10 is below a, a few filters, operating at the lowest r.p.m. suffice. As the amount of concentrate increases, more filters are manually put into operation until at level a, a level-controlled (15) r.p.m. controller 14 is actuated to increase the r.p.m. of the drums. At level b, the r.p.m. is at its maximum (e.g. 2 r.p.m.) for maximum filter capacity. Thereupon a level-controlled (16) valve 17 is opened to add water to the thickened slurry in tank 5, the admission of thickened slurry from cone 2 being simultaneously reduced by valve 4. Such re-diluted slurry produces less concentrate from the plant 9, with consequent lowering of the level in collecting tank 10. The degree of opening of valve 17 depends on the rise of level above b in tank 10. |
