| 摘要 |
915,411. Automatic mixture control. BETEILIGUNGSUND PATENTVERWALTUNGSGESELLSCHAFT. May 23, 1961 [May 24, 1960], No. 18609/61. Class 38 (4). In a system for controlling the concentration of a slurry supplied to a flotation plant a condenser serves to measure continuously the dielectric constant of the slurry, which is dependent upon its concentration, and a mixing and draining valve is controlled in dependence on the difference between the measured value of the dielectric constant and a predetermined value so as to maintain constant the concentration of the slurry. As shown, crude slurry, comprising a charge and water is fed to an agitating vessel 2 from a pipe 1. The slurry is drawn off by a pump 3 and fed through a riser pipe 4, a mixing valve 5 and a tubular capacitor 6 to an overflow vessel 7. The outflow from the overflow vessel 7 to flotation cells 8 is effected through an accumulator valve 9 which maintains constant the total quantity of slurry flowing into the flotation cells 8 per unit of time. The excess of slurry in the overflow vessel is returned to the agitating vessel through a line 10. The condenser 6 is coupled to a recording apparatus 12 which controls through a servomotor 13 and reduction gear 14, the position of a mixing and draining valve 15, variable from a " feed line open " position through a " feed-line " closed position to an " offtake line open " position for controlling the flow of water from a pipe 16 to the mixing nozzle 5. A magnetic valve 17 operated by the recording apparatus 12 interrupts the supply of water from the pipe 16 to the mixing and draining valve. |
