GB960776A - Method of and apparatus for contacting fluids counter-currently within a rotor containing a series of contacting stages - Google Patents

Abstract

In the solvent extraction of a lubricating oil stock with phenol as a selective solvent, the phenol is admitted through the pipe 17 and a dispersion of oil and water is supplied through the pipe 18, both under suitable pressure, and the rotor is rotated. The oil-water dispersion flows radially outwards through the tube 38 and is centrifugally separated as is shown in Fig. 3 to form a layer of water 51 radially outside an interface I and a body of oil collects within the channel 50. The separated water and oil enter the compartments 47 and 48 through the passage-ways 45 and 46, respectively. The deflector 49 prevents direct efflux of the oil-water dispersion through the latter passageway. Various arrangements may be used to regulate the separate efflux of oil and water from the separating chamber. The oil and phenol flow countercurrently through the holes 44 with the oil being discharged via ports 37 to channel 19. In the reflux section radially outward from compartment 48 the solvent moves to compartment 47 where it is mixed with water in the latter; reducing the solvent power of the phenol and causing some of the dissolved oil to be released as reflux. The latter moves radially inwards. The solvent extract phase from the compartment immediately inside the peripheral wall 31 is discharged through such passages as 40, 42, 41a and 40a, and the channel 20. Fig. 4 (not shown) describes a modification by which it is possible to select the compartment to which the oil is charged and/or to alter the area of the oil passageways 46. When the solvent has a lower density than the liquid being extracted the solvent-reducer could be charged in admixture with the heavier principal fluid; the separation chamber would then be situated to discharge into stages near the rotor axis. Further, the density of the solvent reducer may be the same as that of one of the phases, or the density of one of the phases may be between those of the solvent reducer and the admixed principal fluid. In this latter case, the interfacial level within the separating chamber is self-regulating in accordance with the densities, and it is not necessary to restrict the passageway 46. The device would not operate as described if the density of the admixed principal fluid were between those of the auxiliary fluid and the external phase; however, it would still be operative to introduce the auxiliary fluid into a stage between those to which the two principal fluids are charged. U.S.A. Specification 2,857,326 is referred to.ALSO:<PICT:0960776/C4-C5/1> <PICT:0960776/C4-C5/2> In the solvent extraction of a lubricating oil stock with phenol as a selective solvent, the phenol is admitted through the pipe 17 and a dispersion of oil and water is supplied through the pipe 18, both under suitable pressure, and the rotor is rotated. The oil-water dispersion flows radially outwards through the tube 38 and is centrifugally separated as is shown in Fig. 3 to form a layer of water 51 radially outside an interface I. A body of oil collects within the channel 50. The separated water and oil enter the compartments 47 and 48 through the passageways 45 and 46, respectively. The deflector 49 prevents direct efflux of the oil-water dispersion through the latter passageway. Various arrangements may be used to regulate the separate efflux of oil and water from the separating chamber. The oil and phenol flows countercurrently through the holes 44 with the oil being discharged via ports 37 to channel 19. In the reflux section radially outward from 48 the solvent moves to compartment 47 where it is mixed with water in the latter; reducing the solvent power of the phenol and causing some of the dissolved oil to be released as reflux. The latter moves radially inwards. The solvent extract phase from the compartment immediately inside the peripheral wall 31 is discharged through such passages as 40, 42, 41a and 40a, and the channel 20. U.S.A. Specification 2,857,326 is referred to. Fig. 4 (not shown) is a modification by which it is possible to select the compartment to which the oil is charged and/or to alter the area of the oil passageways 46.