GB312997A - Centrifugal sludge separator - Google Patents

Abstract

312,997. Nyrop, A. June 4, 1928, [Convention date]. Density separators, discharging.-A centrifugal separator drum has coniform walls provided at the maximum diameter with one or more sludge outlets, the opening and closing of which are controlled by the differential action between the hydrostatic pressure produced in a cushion of liquid formed between relatively movable parts of the drum, and an oppositely directed pressure produced by springs, or by fluid in a pressure chamber. The shaft 1, Fig. 1, supports a hub 2 attached to the outer bottom bowl 3; an inner bowl part 8 with a hub 7 is firmly attached to the upper part 13 of the bowl by a nut 33, and this can move axially relatively to the bowl 4 to which it is connected by springs 21. A discharge opening 30 in the upper part 13 is normally closed by the projecting ring 26 of the lower part 3, and the springs 21 tend to keep the parts in this position. The liquid to be treated is directed into the opening 32 and separated liquids are discharged from the openings 15, 16, while the sludge remains in the space 23. When sufficient sludge has accumulated a small quantity of liquid is passed into the opening 31 from which it travels to the space 11, where the pressure it exerts lifts the inner bowl 8 and. the part 13 thereby allowing the sludge to be discharged through the opening 30. This action is assisted by liquid which flows from the bowl through the bye-pass 56 as the sludge deposit increases. The lifting of the part 8 uncovers the opening 5 so that the liquid is discharged from the space 11, and the bowl 8 drops for the operation to be repeated. In a modification a filter is employed instead of the discs 29. In the modification shown in Figs. 3 and 4 the lower bowl part 3 can move axially .relatively to the other parts to open the joint 30 for the sludge discharge. The compression chamber 11 is filled with liquid from the pipe 55 and this lifts the part 3 to hold the joint 30 closed. A spring- pressed piston 47 is arranged at the end of a channel 39 which is supplied with liquid from the bowl through the passage 58 as the sludge deposit increases. The pressure of this liquid eventually lifts the piston 47 to uncover the port 48, and the liquid from the chamber 11 then lifts the piston beyond the port 49. 'The liquid in the chamber 11 and the pipe 39 then escapes, the bowl part 3 drops and the sludge discharges through the open joint 30. The escaping liquid from the port 49 rocks the shield 50 to operate an electric switch 52 to close the circuit of a time relay 54 which operates to close the supply pipes 40, 55 and to open them again after a given time interval. A gutter may be provided near the centre of the hub, so that the rising liquid in the drum will overflow into it and then pass to the pipe 39.