Patent GB-571973-A (GB)
Title: An improved method of refining vegetable and animal oils
IPC: C11B3/06
Filed: 1942-12-30
Abstract: 571,973. Refining vegetable and animal oils. CLAYTON, W. L., FLEMING. L., WHITTING- TON, H., FUESLER, J. P., CANNAFAX, D., SUMMERS, D., JOHNSON, J. M., ODEN, C., and KOAR, W. H., (trading as Anderson, Clayton, & Co.). Dec. 30, 1942, No. 18504. [A Specification was laid open to inspection under Sect. 91 of the Acts. Aug. 28, 1943.] [Class 91] [Also in Group XXIX] Fatty oils are purified of free fatty acids and colloidal material such as colouring matter by comingling a stream of the oil with a stream of a neutralising agent, disintegrating the single stream such as by converting it into a spray or mist, collecting the resultant as a liquid emulsion maintained at emulsion breaking temperature on a surface, and finally separating the soap stock formed from the oil. The oil and neutralising agent may be separately disintegrated and the mixed sprays or mists subjected to the process. The negative charge on the highly dispersed colloidal soap neutralises the positive charge on the colloidal material which is thrown out of suspension and is removed with the soap stock. The neutralising agent may be formed in situ in the oil by mixing the oil stream with a stream of a substance which will react to form the neutralising agent such as with water in the oil or with added water; such substances specified comprise sodium carbide, or sodium methylate in alcohol solution. Besides caustic soda, the neutralising agent may comprise substances which form water-insoluble soaps such as the hydroxides of calcium, barium strontium, and magnesium. As a preliminary step, the neutralising agent may be replaced by water. The usual oils are treated with particular reference to cottonseed oil. In a suitable plant for effecting the process the streams of oil and neutralising agent 20, 28 from supply tanks 10 and 11 respectively are fed to a centrifugal atomizing and mix'ng head 46 supported within a steam jacketed reaction chamber 29 and the resultant emulsion collected on the walls of the latter, and broken by the temperature of the walls, is directed through pipe 78 to a centrifugal separator 79 to remove the soap stock. A series of rest tanks 88 to 90 with electrically controlled supply and delivery arrangements mav be provided between the reaction chamber and the centrifugal separator for use in re-refining of the oil to allow the caustic to be sufficiently used up by the reaction with a small proportion of the oil itself that only a one-layer soap stock is produced as in the original oil refining process. A suitable centrifugal atom'sing and mix'ng head 46, Fig 2, comprises a bottom disc port'on 47, threaded on to a rotatable spindle 40, spaced from an upper annular disc portion 49 by a number of closely spaced circularly arranged flat V- shaped blades 50 and also by a series of apertured baskets 51, 53, 55. The basket 53 receives the flared end of a tube 59 connected to the oil pipe 20 the flared end forming a conical nozzle with the flared end of a concentrically related tube 65 connected to the neutralising agent pipe 28, the tube 65 terminating in a nozzle 74 received by the basket 55. In operation, separate mists of the oil and neutralising agent are therefore formed which only mix after they have passed through the basket 53. Several modifications of the mixing and disintegrating apparatus are described; in some forms the two streams are arranged to mix prior to atomizing the combined product. Thus the baskets 51 and 55 may be removed; or the streams are fed to a single nozzle some mixing occurring before issuing therefrom. In the latter form the admission pipes 59 and 65 are parallel to each other; in a variation of this the admission pipes are at right angles to each other. In a form where the streams are mixed and only converted into a spray, the combined stream issues from a single nozzle 136, Fig. 8, arranged at the top of a vertical jacketed pipe 135. Conical baffles 141, 142 are provided to direct the emulsion on to the heated pipe and ultimately to a collecting pan 143. Specifications 531,749 and 537,704 are referred to.