GB613439A - Process and arrangements for the recovery of oils from fat animal matter - Google Patents

Abstract

<PICT:0613439/III/1> Oil is recovered from animal fatty matter, e.g. blubber, by heating the raw material, after mechanical disintegration, to a temperature of 40 DEG to 120 DEG C., after which the oil thereby liberated, possibly together with a certain amount of water and fine solids, is separated out by gravity settling and/or centrifugal separation and the remaining mass cooked in the usual way with high-pressure steam for the extraction of the rest of its oil content. The mechanical disintegration may be carried out by mincing, milling, grinding, or grating, and the raw material may be pre-heated before disintegration. The disintegrated material may be heated by means of continuous heat exchangers of the plate type, in which the mass is divided into thin layers, and may be mixed with hot water which may contain sodium chloride before or during the heating or before and/or during the separation. Where the fat cells of the disintegrated material cannot be burst by heating or adding hot water, protein splitting substances such as enzymes, weak acids, &c. may be added, and where the free fatty acid content of the raw material is abnormally high, alkali may be added to the disintegrated material or to the adding water. The disintegrated material after heating may be strained in self-cleaning strainers, suitably after or during adding of hot water. The disintegrated material after heating may be freed from solids in centrifuges with perforated or solid drum walls before being divided into oil and water components. Strained-off solids may be treated in a suitable press, e.g. a screw press and the press liquid obtained either mixed with the strained liquid or returned to the strainer or used for dilution of the p disintegrated raw material. The solids obtained from the strainer, the press or the centrifuge may be cooked separately or together with meat or bone in an ordinary pressure boiler. The oil component obtained from the centrifugal separation may be purified, after further heating, by passage through a second centrifuge, and may be deodorized or cooled immediately after centrifuging. One or more oxidation inhibitors may be added to the oil or the disintegrated raw material, the heat in the oil and/or hot water may be recovered by means of suitable heat exchangers, and the different operations may be carried out as much as possible in closed apparatus, preferably under vacuum or in inert gas. As shown, the disintegrated raw material from the disintegrator 1 passes into the combined heater and gravity separator 30 in which the oil easiest to liberate is collected and discharged into the heated buffer tank 12. From this tank the oil is fed directly into the secondary separator 8. The rest of the contents in 30 passes to the strainer 14 in which the coarser solids are removed and carried by the conveyer 17 to a boiler. The strained fluid mixture passes via the heated buffer tank 11 to the primary separator 4 in which it is divided into an oil component and a water component. The former discharging from spout 5 passes to buffer tank 12, and a part of the latter, discharging through spouts 6 and 7, is returned to the strainer 14 or the gravity separator 30, the balance going to waste. Hot water may be supplied to 14 and/or 30 from the hot-water tank 3. It is stated that whale oil recovered by the process described may be used without any further treatment for margarine manufacture and retains a great deal of its vitamin content.