GB918438A - Improvements in or relating to means for extracting oil from oil-bearing seeds or nuts - Google Patents

Abstract

<PICT:0918438/III/1> <PICT:0918438/III/2> As shown, an apparatus in which oil is extracted from oil-bearing seed or nut material comprises an aperture 13 (see Fig. 1A) into which the oil-bearing material is fed, and a helical worm conveyer 11 which transports the oilbearing material to vertical shoot 14 which is likewise provided with a worm conveyer 16, which forces the material down through a pair of successive vertical barrel sections 22 and 23 (see Fig. 1). These barrel sections, constructional details of which are given, are so disposed as to prevent solid material from escaping radially outward, but permit liquid to be squeezed through the minute interstices when the pressure is applied. At the lower end of the vertical barrel is an imperforate collar 33 within which the oil-bearing material is compacted into a plug by the gradually increasing pressure; this plug eventually passes into horizontal barrel 34 where it is advanced by means of helical screw flights 36 while gradually increased pressure is exerted. This increase of pressure may be achieved by decreasing the pitch of flights 36, by increasing the shaft root diameter towards the exit end, or by restricting the escape opening within an automatic choke assembly 37. The extracted material eventually leaves the apparatus through aperture 41. The horizontal barrels 34 is also equipped with barrel bars similar to those contained in the vertical section. During its passage along horizontal barrel 34, the material may be treated with an oil solvent, e.g. methylene chloride, trichloroethylene, or heptane, supplied by pipes 71 and 72 and injected into barrel 34 by means of nozzles. The conditions under which this solvent extraction is performed are so chosen that the solvent will flash off the miscella at the barrel bar interstices with sufficient force to atomize the entrained dissolved oil into a mist of oil particles; these oil particles collect within housing 67 or on the inner wall of the housing and are removed by means of lines 76 and 78. The oil extracted by means of pressure only in the vertical section of the apparatus collect in trough 49 whence it may also be removed (means not shown). In a further embodiment (not shown), the solvent extracted cake in horizontal barrel 34 may be treated with injected water or steam near the discharge end of the barrel; this injection of water cools the cake, produces steam in the barrel, and so desolventizes the cake in a single operation.