GB1039031A - Separation process and apparatus - Google Patents

Abstract

1, 39, 031. Centrifugal separaters. ESSO RESEARCH & ENGINEERING CO. Feb. 21, 1963 [Dec. 4, 1962], No. 7050/63. Heading B2P. A disc -stackcentrifuge comprises a stationary casing 25 and a rotatable bowl 41 which consists of lower and upper members 26, 27 joined together and defining a double frusto-conical space including a separating chamber 11 in which stacked conical discs 7, 8 and 10 are mounted around a centre part 6 and rotate with the bowl. The lower conical disc 10 is supported by struts 50 from the part 6 and extends downwardly and upwardly to define with the inner surface 15 of the bowl member 26 a passage 56 open at its upper end to the separating chamber 11. An axial first inlet 1 leads through the bowl member 26 to the separating chamber 11; a second inlet 28 coaxial with the first communicates with the passage 56; an axial outlet 19 leads from the top of the bowl member 27; and a number of discharge nozzles 9 are arranged radially at the junction between the bowl members 26 and 27 and extend into the separating chamber 11. Accelerator vanes extend between the inner periphery of the bowl and the outer periphery of the disc stack. The operation, when separating solid particles from a light feed liquid, e.g. crystalline wax from oil, the mixture of light liquid and solid particles is fed through the inlet 1 and after impinging on a curved surface 46 at the bottom of the post 6 is thrown outward by the action of centrifugal force and by vanes (not shown) in the space 2 towards the separating chamber 11 where it rises through holes 4 in the stack of discs, separation between the liquid and the solids taking place between the discs. The clear liquid rises through holes 5 in the discs and is discharged via the outlet 19 into a chamber 22 and out through a conduit 23. The solids and part of the light liquid fill part of the space between the outer periphery of the disc stacks and the inner periphery of the bowl. Auxiliary liquid, e.g. calcium chloride brine, heavier than the light liquid and the solids is fed, via an inlet 31, a chamber 29 and openings 30, through the inlet 28 and passage 56 into the chamber 11 where it fills the space 16 between the bowl inner periphery and the nozzle inlet opening 13 and forms a liquid-liquid interface 40 with the light liquid component on which the solid particles float. As the heavy auxiliary liquid discharges through the nozzles, it picks up the floating solid particles and carries them out of the bowl towards a discharge outlet 21. Some of the auxiliary liquid may also be fed with the mixture of light liquid and solids through the inlet 1 in order to facilitate separation in the disc stack. The centrifuge may also be used for the separation of solids from a mixture of two liquids of different densities, the heavier liquid being removed with the solids.