GB709127A - Method and apparatus for the upward current separation of particles - Google Patents

Abstract

709,127. Upward-current separators. MAATSCHAPPIJ VOOR KOLENBEWERKING STAMICARBON, N.V. July 2, 1951 [July 5, 1950], No. 15661/51. Class 82 (2) [Also in Group XXIX] A constant upward current velocity is ensured in an upward current separator by maintaining constant the principal current-producing force, e.g. the force exerted by a liquid head or pump and introducing into the upward current a gas which rises in and increases the velocity of the upward current and escapes from the surface thereof, the rate of supply of the gaseous medium being automatically varied in dependence on the liquid level in the separator. An upward current is produced in the vessel 2 by means of a propeller 4 in the pipe 3; material to be separated is introduced at 1; sinks are removed by the elevator 5 and floats pass over the overflow 6 and screen 7 to the discharge 8; liquid passes through the screen 7 into the pipe 3; and air is introduced into the vessel 2 through the pipe 20. The air supply to the pipe 20, from a compressed air source, is controlled by the diaphragm valve 18, the annular space 17 of which communicates through the pipe 16 with the bore 13 of a rotating valve, the rotary bushing 12 of which is connected by the arm 10 to the float 9. Radial ports are provided in the gudgeon 11 and bushing 12 of the valve and the pipe 16 is connected to the compressed air source through a throttle valve 19. Thus, as the height of liquid in the vessel 2 falls, the bushing 12 is angularly displaced so that air from the pipe 16 can escape through the radial ports in the parts 11, 12, so reducing the pressure in the space 17 and allowing more air to pass through the pipe 20. The float 9 may be replaced by electrical contact devices or air bubbling devices or the float may be connected directly to the regulating member.