SE327184B - - Google Patents

Abstract

1,090,502. Hydrocyclones. BAUER BROS.CO. March 29, 1966 [April 2, 1965], No. 13780/66. Heading B2P. In a hydrocyclone having a separating chamber with a tangential feed inlet 26 adjacent one end, Fig. 1, a portion 25 of the separating chamber has an arcuate surface 17 the radius of curvature of which is smaller than than that of an adjacent portion 12 of the chamber so as to produce towards at least one end of the chamber a ledge 28 operative to disturb flow down the chamber wall. The hydrocyclone is particularly suitable for separating relatively light useable fibrous material from relatively heavy impurities in a flowing liquid pulp slurry for paper-making. The usable fibrous material is discharged through a vortex finder 19 and the impurities are removed at the apex of the conical part 11 of the hydrocyclone. The vortex finder projects into a cylindrical sleeve 14 and definies with the eccentric bore wall 17 thereof the annular chamber portion 25. A segment of the wall 17 is in alignment with the wall of the chamber 12 whereas another segment is radially inwardly displaced from the latter at a relatively thicker section of the sleeve 14 which overlaps the part 11 to provide the arcuate ledge 28. In operation, turbulence will be created at the location of the ledge in the helically downwardly flowing slurry and will prevent impurities from assuming a position of equilibrium in the separating chamber and go into a more or less fixed orbit from which they may eventually leave to appear in the usable fibrous material. The turbulence also prevents increased consistency of the pulp in the region of the separator wall which may prevent the impurities from reaching the wall as a result of which they could be entrained through the vortex finder. In modifications, (a) the ledge 28 may be located at any point along the length of the bore 17; (b) the bore 17 may be made larger than shown so that the ledge is provided by an arcuate portion of the base end of the part 11, i.e. facing toward the inlet 26 instead of away from it as shown; (c) instead of vortex finder 19 being eccentric to bore 17 as shown, it is made concentric therewith and part 11 is made eccentric to both; (d) instead of the sleeve 14 arrangement, an upper cylindrical part 32 of the hydrocyclone, Fig. 5, may be formed integral and coaxial with a lower conical part 33 and a crescent-shaped insert 34 is installed in the part 32 to form a ledge 36 facing upwards and another ledge facing downwards; (e) the separator may be wholly conical in configuration and respective sections of it may be eccentrically offset to produce a flow disturbing ledge.