Patent GB-727148-A (GB)
Title: Improvements in or relating to drying biological substances by distillation
IPC: F26B5/00
Filed: 1952-03-19
Abstract: Stick water, i.e. the aqueous liquid produced in the hydraulic extraction of oil from fish, contains substantial proportions of Vitamin B12 and is a desirable source of the vitamin for animal feed. The stick water is dehydrated by azeotropic distillation (see Group III) to give a powder of unimpaired Vitamin B12 content.ALSO:A biological substance, e.g. blood, various glands, aqueous extracts obtained in the steam rendering of fish, oil and lard, is dried by mixing the substance with an organic liquid, which is capable of forming an azeotrope with water, to form a fluid pumpable mixture, and introducing the mixture into a boiling body of the organic liquid whereby the water in the biological substance, together with some of the organic liquid, is evaporated at a temperature below 100 DEG  C.; the particles of dried biological substance are then separated from the residual organic liquid.  In order to obtain solid material, such as pancreas, liver or thyroid, in pumpable form, it is comminuted and then made into an emulsion with the organic liquid.  The fluidized substance is preferably injected in the form of minute droplets into the boiling organic liquid.  Ethylene dichloride and other low-boiling chlorinated aliphatic hydrocarbons may be used as the organic liquid.  Hydrocarbons such as benzene, hexane, and cyclohexane may also be used.  When the coagulation of proteins and deactivation of enzymes is not desired, the process is carried out at a temperature in the range of 30 DEG -50 DEG  C. by maintaining the system under reduced pressure (50-250 mm.).  A vertical column containing baffles is filled with the solvent, which is heated until it boils violently; the fluidized biological substance is then sprayed or atomized, by means of jets or rotating discs, into the body of the boiling solvent or into the vapour space above it.  In an example, "stick water" produced in the hydraulic extraction of oil from fish, is dehydrated at 71 DEG  C. and atmospheric pressure, using ethylene dichloride as solvent.  The product produced is an animal food rich in vitamin B12.  In another example, beef blood is emulsified with cold ethylene dichloride, and injected as spray below the surface of boiling solvent, at 71 DEG  C.  The drying of human blood is referred to.ALSO:Biological substances, e.g. eggs, various glands (liver, kidney, heart), blood, aqueous extracts obtained in the steam rendering of fish oil and lard (stick water), are dried and defatted by introducing the substance in fluid form into a boiling organic liquid which forms an azeotrope with water, whereby the water in the biological substance, together with some of the organic liquid, is evaporated at a temperature below 100 DEG C.; the particles of dried biological substance are then separated from the residual organic liquid, and are washed with fresh liquid in order to remove fat solvent.  In order to obtain solid material, such as liver, in fluid form for treatment, it is comminuted and made into an emulsion with some of the organic liquid.  For substances which are difficult to emulsify, an emulsifying agent is used.  In the case of a product for human consumption, the emulsifying agent may be corn oil, peanut oil, or an animal oil such as a portion of the oil extracted from the material being dried and defatted.  Fresh blood is dehydrated and defatted at 38 DEG C. by reducing the pressure in the distillation apparatus.  The dried blood can be reconstituted by adding saline solution.