| 摘要 |
1532234 Jigging and screening materials SIMONACCO Ltd 11 May 1976 [25 June 1975] 26897/75 Heading B2H [Also in Division G3] A float 24 in a coal washbox oscillates with pulsations of liquid within the box and operates an actuator at one rate as the mean level of the float rises and at a lower rate as the mean level of the float falls. A mixture of waste material and coal is fed through a chute 11 to a perforated deck 13 where the waste material settles whilst the coal floats near the surface and spills over a sill 17 into an outlet chute 12. Fine particles of waste material pass through perforations in the deck while the remainder of the material passes over gates 14 to be received by bucket elevators 19 which also receive material from screw conveyors 18 beneath the deck. When the quantity of material on the deck is excessive the mean level of the float rises and a striker 26 engages a stop 27 on an endless chain 28 which operates a regulator 31 through a shaft 30 and a cam 31. A valve 22 controlled by air pressure from the regulator connects the space above the liquid with atmosphere so that pulsation of the liquid is increased to lift waste material over the gates 14. When the liquid level falls again, the striker engages a stop 36 on a second endless chain 34 connected with the cam 31 through a one-way drive and a reduction gear so that the valve 22 closes more slowly. A number of valves may be controlled from a single regulator. |
