GB1038559A - Process and apparatus for separating solids from liquids - Google Patents

Abstract

1,038,559. Centrifugal separators; centrifugal strainer separators; separating solids. KRAUSS-MAFFEI A.G. Oct. 31, 1963 [Dec. 5,1962; June 10, 1963], No. 43000/63. Headings B1D; B2H and B2P. A suspension of solids in liquids is passed as a thin film over a separation surface and a centrifugal or gravitational force not greater than the adhesive force between the liquid and the surface is applied to the film whereby the solids are removed from the suspension whilst the liquids remain as a thin film on the separation surface. Where solids of different sizes are present the process effects classification according to size, and the apparatus may include devices for collecting different fractions. In Fig. 6 the first "separating surface" is that of a rotating body 2 into a depression in which the suspension is fed by a pipe 5. Liquid is centrifugally discharged from the outwardly-splayed lower part of the body 2, while solids are discharged higher up and are deflected by a baffle 20 to the lowermost of a series of rings 33. Liquid is discharged over the lip of the lowermost ring according to the process of the invention, whilst solids are discharged outwards to impinge on the next higher ring 33, where the process is repeated, and so on. Classifying devices In Fig. 2, (not shown), a rotating body 2 with top feed is surrounded by a number of nearlyhorizontal annular plates forming between them collection chambers for solids of different sizes. In Figs. 12 and 13, (not shown), a structure akin to Fig. 6, but with only one ring 33, is provided with a vertically-adjustable baffle around the body 2, so that more or less of the coarse solids, together with the fine solids, may be discharged with the liquid. Fig. 13 has further fixed baffles for classify ing the coarse solids into two fractions. Fig. 17 is a purely-gravitational device with, on the right, provision for collecting coarsest solids at 85 and less coarse solids at 78. In each case liquid is collected at 79. Centrifugal (only) separators Fig. 5 (not shown), resembles Fig. but has only the lowermost ring 33, made solid. Fig. 1 (not shown), resembles Fig. 2 but has only one annular plate to separate liquid from solid. Fig. 9, (not shown), is a refinement of Fig. 6 with a horizontal baffle above each ring. Fig. 10, (not shown), consists of two rotatable spaced horizontal discs, the lower having a concentric series of spaced rings 33, and the upper having a similar series directed downwardly to occupy part of the spaces between the lower rings. The solids follow a zigzag path, moving to and over each ring in turn outwards, while the liquid is collected from the edges of the discs. Centrifugal strainer separators Fig. 3, (not shown), has the body 2 and baffle 20 of Fig. 6 located at the base of an upwardlydiverging centrifuge basket, with peripheral base holes for discharge of liquid from body 2. Fig. 4, (not shown), depicts a body 2 located in the inlet "funnel" of a pusher centrifuge with separate liquid discharge. Fig. 11, (not shown), depicts an upwardly diverging basket surmounted by two rings 33. Figs. 7 and 8, (not shown), depict an upwardly diverging basket made up of solid rings, the lip of each being higher than the lower edge of the next higher ring. Gravity (only) devices The left hand side of Fig. 17 shows separate solid and liquid discharge without classifying. Figs. 14 to 16, (not shown), show arrays of rods (solid or hollow) arranged horizontally in series so that liquid from any rod falls from its lowermost directrix on to the top of a lower rod or discharge while solids discharge tangentially from higher directrices.