| 摘要 |
1,263,487. Hydrocyclones. C. M. SLIEPCEVICH and HENRY PA-HOUNG SHENG. 25 June, 1969 [24 July, 1968], No. 32176/69. Heading B2P. [Also in Division C5] In a process for separating a liquid mixture into fractions of different densities, the mixture is subjected to centrifugal separation by flowing it tangentially into a chamber, the mixture coming into contact with first and second surfaces of the chamber, the first surface being constituted by a material which has a greater affinity towards the lighter fraction than towards the heavier-fraction and the second surface being separate from the first surface and constituted by a material which has a substantially equal affinity towards each of the fractions or a greater affinity towards the heavier fraction, the contact of the mixture with the surfaces enhancing its separation into the said fractions, and the fractions are then separately removed from the first and second surfaces respectively. The apparatus used for carrying out the process may consist of a hydrocyclone in which the vortex finder tube, or a portion thereof, is constructed of, or lined with, a material which is preferentially wetted by the relatively less dense liquid or liquids in the mixture, the selective affinity exerted by the preferential wetting of the material thus enhancing the separatory effect of centrifugation. In Fig. 4, a hydrocyclone, which may be used for separating saturated paraffin hydrocarbons from water, consists of a metallic housing 42 which is internally lined as at 46 with glass. The discharge conduit 44 may also be similarly lined for a short distance. A vortex finder tube 50 which may be threaded through the top of the housing is made of polyethylene. Secured by an end cap 52 at the inlet end of the tube 50 is a grid 54, Fig. 5, which is also constructed of polyethylene and acts as a gate which selectively passes wetting material (hydrocarbon) but tends to reject or block non-wetting material (water). The grid may be mounted further downstream in the tube 50. Other organic plastic materials which may be used for the construction of the vortex finder and of the grid include P.T.F.E., polystyrene and nylon. The wettability of the material chosen may be increased by roughening its surface. Results of an experiment using a hydrocyclone made of glass and a vortex finder tube made alternatively of glass, nylon and polyethylene are given, the mixture separated being one of a paraffin hydrocarbon, polyethylene particles and water. The polyethylene particles exert a separatory effect due to preferential wetting by the hydrocarbon and this prevents the latter from emulsifying with the water. |
