GB823828A - An improved method and apparatus for filtering or screening thick sludges, for example raw cement slurries - Google Patents

Abstract

823,828. Centrifugal strainer separators. CIMENTS D'OBOURG S. A. Aug. 30, 1957 [Nov. 9, 1956], No. 27463/57. Class 46. Sludge, (e.g. raw cement slurry), is supplied by a pipe 9, Fig. 1, to a distributing head 15 and falls thence on to a centrifugal disc 6 which has a rim 20 whose upper edge may be in the form of two juxtaposed ascending portions as shown. Coarse material settles to form a deposit 16, Fig. 7, within the rim, while the remaining slurry is distributed over the rim to impinge upon a stationary screen 7 over a range of heights. Screened slurry is discharged at 13, while residue falls into a funnel structure at 10 and may be fed to a further disc 6a for distribution to a further screen 8. The final residue is discharged at 12. The disc may have vertical vanes (e.g. 24, Fig. 7). The rim of the disc may be of constant height throughout. The screens 7, 8 are preferably composed of spaced vertical wires 30, Fig. 8, connected and spaced by horizontal wires 31 each of which is wrapped once round each wire 30 in turn. The wires 30, 31 are vulcanised into layers of rubber 32 where shown. Alternatively the wires 30 may be spaced and connected by horizontal perforate metal strips through which the wires pass. Each screen is preferably polygonal in plan and composed of several flat elements, alternatively the elements may be arcuate and the screen cylindrical. The sludge may be fed tangentially into the distributing head 15 in the same direction as that of rotation of the disc. Several discs may be mounted on a hollow shaft through which residue is fed for distribution to all the discs at once. The residue may be fed to further discs located under the first ones.