GB1180627A - Improvements in or relating to Solid Jacket Centrifuges - Google Patents

Abstract

1,180,627. Centrifugal separators. MASCHINENFABRIK BUGKAU R. WOLF A.G. 10 July, 1967 [20 Aug., 1966], No. 31724/67. Heading B2P. In a centrifuge for treating liquid suspensions, e.g. of a granular plastics substance, and comprising a drum having a peripheral discharge aperture defined between parts 3, 4 of the drum, the discharge aperture is opened or closed by means of a resilient sealing member which is actuated by liquid fed into an annular chamber 12 in the drum part 4 through at least one passage such as 14 or 16 and discharged through at least one outwardly extending passage 15 the cross-sectional area of which is smaller than that of the passage 14 or 16. The drum has a jacket consisting of a fixed part 2 secured by bolts 5 to the bottom 4 of the drum and an axially displaced part 3 which in its closed portion bears on a stop 2a to define a gap 11 with the bottom 4, the gap being of such width as to allow the passage of liquid but not of solids. The drum bottom 4 is mounted by means of webs 6 on a hub, and is provided with a central aperture, the edge of which is spaced from a closure cone 9 by means of a narrow gap 10. In the operation of a centrifuge having only one feed passage 14, the suspension is introduced into the separating chamber 8 with the jacket part 3 in the closed position. When the chamber is filled to such an extent that the liquid reaches the mouth of the passage 14, liquid will flow through the latter into the chamber 12 where under the effect of centrifugal force it will force the sealing ring 13 against the face 3a of the jacket part 3 so as to close the discharge aperture. A small quantity of liquid will flow continuously from the chamber 12 through the passage 15. Separated solids will accumulate in the chamber 8 and clarified liquid will discharge through the gap 10. When the level of accumulated solids has reached such an extent that the liquid flowing out of the gap 10 becomes turbid, feeding of further suspension into the drum is stopped and the centrifuge empties itself except for the accumulated solids. Since then less liquid enters the chamber 12 than leaves it, the ring 13 is no longer under pressure and opens the discharge aperture through which liquid still present in the chamber 8, i.e. in the interstices between the accumulated solid particles, is centrifuged out as it passes through the gap 11. When the remaining liquid has been centrifuged, the jacket part 3 is displaced upwardly by mechanism not shown to allow for discharge of the separated particles. Washing liquid may be introduced into the drum to wash the particles before displacement of the jacket part 3. The feed passage 14 may be dispensed with and the drum bottom 4 may be provided with a concave pocket communicating with the chamber 12 through one or more passages 16 so that the liquid on discharging through the gap 10 is caught in the pocket and part of it flows through the passages 16 into the chamber 12. Reference has been directed by the Comptroller to Specification 969,179.