Patent GB-1112303-A (GB)
Title: Clarifying centrifuge for separating a suspension into liquid and solid
IPC: B04B1/20
Filed: 1965-06-16
Abstract: 1,112,303. Centrifugal separators. ESCHER WYSS A.G. 16 June, 1965 [24 June, 1964], No. 25536/65. Heading B2P. A centrifuge for separating the components of a liquid-solid suspension comprises a conically flared, solid-wall drum 1 the interior of which is sub-divided in the axial direction into two or more separating chambers 4<SP>1</SP>-4<SP>3</SP>. through which the suspension flows successively by means of partitions 6<SP>1</SP>-6<SP>3</SP> extending at least to the vicinity of the inner surface of the drum wall with which each partition defines or is adapted to define a gap 7<SP>1</SP>, 7<SP>2</SP> or 7<SP>3</SP> for the discharge of separated solid deposited on the wall surface, each partition being provided with an overflow aperture 8<SP>1</SP>, 8<SP>2</SP> or 8<SP>3</SP> for the passage of the suspension or discharge of clarified liquid. The drum 1 is secured to a rotatable shaft 2. The partitions 6<SP>1</SP>-6<SP>3</SP> are connected by a tubular support 9 connected to a sleeve 10 by means of cross-pieces 9<SP>1</SP> extending through openings into the hub disc of the drum. The width of the gaps 7<SP>1</SP>-7<SP>3</SP> may be adjusted by axial movement of the sleeve 10. Adjustment of the sleeve 10 can be effected in accordance with the quantity of solid discharged into the housing 15. A vibratory motion may be superimposed on the adjusting movement of the sleeve 10 to prevent solid clogging the gaps. Instead of a common adjustment, each partition may be independently adjusted by leaving the partition 6<SP>1</SP>, 6<SP>2</SP> slidably mounted on the support 9 and connected by cross-pieces to sleeves 10<SP>1</SP>, 10<SP>2</SP>. Adjustment of the partitions may be effected in accordance with the amount of solid present in the separating chambers, the sleeves at the start of an operation being drawn by a spring in to a position corresponding to the closure position of the partitions. As the amount of solid increases in any one chamber the pressure on the respective partition increases and the partitio moves against the biasing action of the spring to provide the necessary width of gap. The suspension is fed through a stationary pipe 5 and passes successively through the chambers 4<SP>1</SP>, 4<SP>2</SP>, 4<SP>3</SP> where the liquid is increasingly clarified. The clarified liquid discharges via a funnel 11 into a discharge housing 14. The path of the liquid being clarified may be further extended by providing one or more of the partitions with an additional wall 30, Fig. 4 (not shown) in front of or after the corresponding overflow aperture 8. In another embodiment, Fig. 2 (not shown), the drum 1 is connected at its wider end to a conical screwtype centrifuge, the solid discharging from the drum 1 being conveyed to a discharge 22 by the screw-conveyor 17, which rotates at a speed different from that the centrifuge drums 1, 16. The suspension is fed to the narrower end of the drum 1 via the inlet 5 and a distributor head 23 carried by the shaft 2. The clarified liquid discharging from the drum 1 flows via a take-off device 21 into a stationary discharge pipe 20. In a modification of the last embodiment, Fig. 3 (not shown), the suspension is fed to the larger end of the drum 1, the clarified liquid discharging at the narrower end and the solid at the larger end and into the drum 16. In a further embodiment, Fig. 5 (not shown), the drum 1 is connected to a scraper centrifuge drum 31 into which the suspension is fed via the pipe 5 and an annular duct 38. The partially clarified liquid passes via the opening 35 of the drum 31 into the drum 1 for further clarification. Solids deposited in the drum 31 are removed periodically by means of a scraping device 40.