GB553501A - A method of, and means for, producing oil from fish liver - Google Patents

Abstract

553,501. Cutting fish livers. AKTIEBOLAGET SEPARATOR. Nov. 7,1941, Nos. 14369 and 14370. Convention dates, Nov. 7, 1940, and June 7, 1941. [Class 5 (i)] [Also in Group III] Fish liver oils are obtained from the fish livers by cutting up the livers to a finely divided mass by means of an apparatus provided with rotating, axially extending straight or helical knives, and one or more stationary knives past which the rotating knives move at a distance determined according to the size of the cut material, and then separating the oil therefrom in a centrifugal separator. The bowl of the latter is provided with outlets for continuous discharge of the oil and the sludge-containing water. The liver may be warmed prior to or after cutting to a temperature innocuous to the vitamins i.e., to below 60‹C. and usually from 40‹-50‹C. The finely divided mass may be diluted with water. These two steps may be effected, if desired, by adding warm water to the storage tank or to the bowl of the centrifugal separator. A secondary quality oil may be obtained from the sludge-containing water by boiling it and obtaining the oil by gravity settling or centrifuging. The cutting apparatus is preferably one with rapidly revolving knives and may operate continuously or intermittently. When used on fishing vessels, the apparatus may be mounted by a cardan arrangement. A prefered cutting apparatus comprises a rapidly revolving drum or rotor, provided on its circumference with axially extending straight or helical knives 4, housed within a casing 5-6 provided on its inner side with one or more fixed knives 9. the distance between the revolving and the fixed knives being adjustable according to the desired degree of cutting. The housing consists of a fixed lower part 5 and hinged thereto at 18, a tiltable upper part 6, the former being provided with a discharge 8 and the latter with a feed inlet 7. The edges of the revolving knives may be even or toothed. The fixed knives 9 are formed of steel blocks with sharp edges on the sides towards the rotor and are adjustable in the radial direction by screws 10. A feeding device may be provided with the cutting apparatus to form a single unit, the device preferably consisting of a housing 12 and an endless feed screw 14. The unit may be part of a closed system filled with a protecting vapour, such as an inert gas or steam.