Patent GB-1446176-A (GB)
Title: Hydrocyclone separator unit with down-flow distribution of fluid to be fractionated and process
IPC: B04C5/28
Filed: 1973-10-03
Abstract: 1446176 Hydrocyclone separators N A L WIKDAHL 3 Oct 1973 [4 Oct 1972 6 Aug 1973] 46234/73 Heading B2P In a process of fractionating a liquid-solids suspension in an array of hydrocyclones 1, Fig. 2, arranged in a plurality of superimposed layers, each hydrocyclone having an elongate vortex chamber provided with an inlet 3 for the suspension, a light fraction outlet 5 and a heavy fraction outlet 4, at least a part of the suspension to be fractionated is fed to the inlets 3 of the hydrocyclones in the array by downflow from the uppermost to the lowermost of the hydrocyclone layers and the heavy and light fractions discharged from the hydrocyclone outlets 4 and 5 respectively are separately collected. The hydrocyclones are mounted horizontally or at an angle in a housing, being supported by a wall 10 of the housing and by internal walls 8, 9. The latter define with each other a distribution chamber 2 and, with the housing walls, light and heavy fraction collection chambers 6, 7 respectively. The suspension is fed through a valve-controlled inlet 17 to the distribution chamber and the light and heavy fractions are removed from the chambers 6 and 7 through valve controlled outlets 18, 19. Each hydrocyclone is provided with one or more tangential inlets 3. Accummulated gases are removed from the top of the chambers 2, 6 and 7 through valve controlled outlets 2', 6' and 7'. In a modification, Fig. 3 (not shown), the suspension to be fractionated is fed through a central inlet conduit extending through the bottom wall of the housing and opening at its upper end in the upper portion of the distribution chamber above the upper hydrocyclone layer. In a further modification, Fig. 4, the hydrocyclones are radially and annularly arranged around a central vertical axis in a cylindrical housing in which they are supported by two concentric tubes 35, 36. A central feed tube 26 is joined at 33 to the tube 35. The hydrocyclones have their heavy fraction outlets facing inwardly and communicating with collection chamber 28. To maintain a high flow rate, heavy fraction passes from the collection chamber 28 through openings 46B in the tube 35 into the distribution chamber 27 and is recirculated. In a modification of the Fig. 4 embodiment, Fig. 6 (not shown), the light fraction outlets of the hydrocyclones are axial and open inwardly in the inner collection chamber whereas the heavy fraction outlets open outwardly in hollow cylindrical members which extend between the housing cylindrical wall and the outer-tube wall and which are provided with lateral outlets communicating with the heavy fraction collection chamber defined between these walls. In a further embodiment, Fig. 8, the casing 81 has a top 83 which may be integral or attached thereto and a bottom 82 which may be connected thereto with a leak-proof seal therebetween or which may be attached thereto by means of a threaded socket or joint. The hydrocyclones are mounted in openings in the casing 81, and in shells 86 and 88. A central cylindrical shell is provided at 87. The shells 86, 87 are supported by legs 94 attached to the bottom 82 of the casing. A hydraulic lifting device (not shown) could be used to lift the casing 81 and its top 83 and would be attached to the top 83 and extend within the shell 87 to a spider support attached to the bottom of the shell. The distribution chamber 96 is in communication with the inlet 118 both at the top via the space 124 and the central space 120 within the shell 87 and at the bottom via passages 119 between the support legs 94. The flow in the chamber 96 is therefore both upwardly and downwardly, the two flows meeting in the central portion of the chamber providing cross-currents there which further improve circulation and fluid distribution through the chamber. The hydrocylones and housings may be made of metal, ceramic, glass or plastics. The hydrocyclones may be wholly frusto-conical or partly cylindrical and partly frusto-conical, the conical surface being straight, convex or concave sided.