Patent GB-468695-A (GB)
Title: A process and apparatus for splitting up a liquid mixture into its components or groups of components
IPC: B01D11/04
Filed: 1936-01-06
Abstract: In the process of separating a liquid mixture (A + B) into its components by means of a solvent S selective for A, and backwashing the extract in countercurrent with a liquid consisting mainly or entirely of A, the washing stage is carried out in a series of two or more mixers and settlers and controlling the miscibility of the phases by maintaining the temperature of at least one mixer or settler different from that of the others and at a temperature below that of complete miscibility.  A suitable temperature is 30 DEG  C. below that of complete miscibility.  The particular temperatures used depend upon the miscibility of the phases present; this usually increases with tempera <PICT:0468695/IV/1> ture, but the reverse may also occur as for example in the ternary system, phenol, lubricating oil, and propane.  In the first case, the inlet of the washing agent should be at the lowest temperature, and the temperature increases in the direction of flow of the washing agent.  The temperature control may be used before the mixer when both mixer and settler are controlled, or used in the settler only.  Diluents may be used to reduce viscosity of the mixture when necessary, and are preferably removed with component A.  The diluents reduce the solubility of B in solvent S.  The process may be applied to the extraction of (1) Diesel oils with SO2; (2) benzine containing aromatics with furfurol; (3) coal tar with alcohol to remove phenols; (4) concentration of dilute acetic acid solutions with methyl acetate; and to the separation of (1) glycol and glycol ethers by ether, (2) isopropyl alcohol and acetate by benzol, (3) ethyl acetate and alcohol by calcium chloride solution, (4) glycol and glycerine by chloroform, (5) methyl and amyl alcohol by heptane, (6) glycerine and nitroglycerin by water, (7) sulpho-acids and petroleum oils by ether or a higher alcohol, (8) glycol and glycol chlorhydrin by ether or a mixture of secondary alcohols, (9) water and chlorhydrin by ethylene chloride, (10) lubricating oil by furfurol, nitro-benzol, liquid sulphur dioxide or dichlor-diethylether, (11) ethyl alcohol and water by kerosene. For example, 9 mixers and settlers are used, furfurol is introduced at 9th mixer, and the oil at the 4th.  Temperatures used are (1st mixer) 28 DEG C., increasing in stages to 67 DEG  C. (9th mixer).  A liquid mixture is fed through a heat-exchanger 47 and flows through mixers 2a . . . c and settlers 3a . . . c in countercurrent with an extracting agent fed through a pipe 4. Raffinate flows through a pipe 10 to a still 11 where solvent is removed.  The extract passes through a pipe 9d to a series of mixers 2d . . . f, and settlers 3d . . . f in countercurrent with the extract.  The extract (free from B) passes through a pipe 17 to a still 18 where solvent is removed and a part of the extract returns through a pipe 21 to the washing system.  Temperature control is effected by heating or cooling devices 1a . . . c, and 6a . . . f. The mixing device consists of a chamber filled with one liquid in which rotates a number of orifices fed with the second liquid.  The settler consists of a horizontal drum having a header containing a perforated plate in which a series of horizontal tubes are mounted, at the remote ends of which is mounted a vertical horizontal baffle upon which the mixture issuing from the pipes impinges and returns the liquids through the lower pipes.  Specifications 390,716, 417,617, 452,427, and 452,537 are referred to.ALSO:In the process of separating a liquid mixture (A + B) into its components by means of a selective solvent S for A, and backwashing the extract in countercurrent with a liquid consisting mainly or entirely of A, the washing stage is carried out in a series of two or more mixers and settlers and also controlling the miscibility of the phases by maintaining the temperature of at least one mixer or settler different from that of the others, and at a temperature below that of complete miscibility.  A suitable temperature is 30 DEG  C. below that of complete miscibility.  The particular temperatures used depend upon the miscibility of the phases present; this usually increases with temperature, but the reverse may also occur as for example in the ternary system, phenol, lubricating oil, and propane. In the first case, the inlet of the washing agent should be at the lowest temperature, and the temperature increases in the direction of flow of the washing agent.  The temperature control may be used before the mixer when both mixer and settler are controlled, or used in the settler only.  Diluents may be used to reduce viscosity of the mixture when necessary, and are preferably removed with component A. The diluents reduce the solubility of B in solvent S.  The process may be applied to the extraction of (1) Diesel oils with SO2; (2) benzine containing aromatics with furfurol; (3) coal tar with alcohol to remove phenols; to the concentration <PICT:0468695/III/1> of dilute acetic acid solutions with methyl acetate; and the separation of (1) glycol and glycol ethers with ether, (2) isopropyl alcohol and acetate by benzol, (3) ethyl acetate and alcohol by calcium chloride solution, (4) glycol and glycerine by chloroform, (5) methyl and amyl alcohol by heptane, (6) glycerine and nitroglycerin by water, (7) sulpho-acids and petroleum oils by ether or a higher alcohol, (8) glycol and glycol chlorhydrin by ether or a mixture of secondary alcohols, (9) water and chlorhydrin by ethylene chloride, (10) lubricating oil by furfurol, nitro-benzol, liquid sulphur dioxide or dichlor diethylether, (11) ethyl alcohol and water by kerosene.  For example, 9 mixers and settlers are used, furfurol is introduced at the 9th mixer, and the oil at the 4th.  Temperatures used are (1st mixer) 28 DEG  C., increasing in stages to 67 DEG  C. (9th mixer). A liquid mixture is fed through a heat-exchanger 47 and flows through mixers 2a . . . c and settlers 3a . . . c in countercurrent with an extracting agent fed through a pipe 4. Raffinate flows through a pipe 10 to a still 11 where solvent is removed.  The extract passes through a pipe 9d to a series of mixers 2d . . . f, and settlers 3d . . . f in countercurrent with the final extract.  The extract (free from B) passes through a pipe 17 to a still 18 where solvent is removed and a part of the extract returns through a pipe 21 to the washing system. Temperature control is effected by heating or cooling devices 1a . . . e, and 6a . . . f.  The mixing device consists of a chamber filled with one liquid in which rotates a number of orifices fed with the second liquid.  The settler consists of a horizontal drum having a header containing a perforated plate in which a series of horizontal tubes are mounted, at the remote ends p  of which is mounted a vertical horizontal baffle upon which the mixture issuing from the pipes impinges and returns the liquids through the lower pipes.  Specifications 390,716, 417,617, 452,427, and 452,537 are referred to.