Patent GB-156647-A (GB)
Title: Improvements in the process of, and apparatus for, extracting glue from glue-yielding raw material by means of steam and water
IPC: C09H3/00
Filed: 1921-01-06
Abstract: 156,647. Niessen, K. Dec. 8, 1919, [Convention date]. Addition to 156,646. Fats and fatty oils, extracting. - The apparatus described in the parent Specification for the extraction of glue and fats from bones, gristle, leather waste, animal skin, fish waste, &c., is modified by (1) employing only one extractor, (2) constructing the extractor of two compartments, in each of which low-pressure steam and water boiling under reduced pressure act upon the material in an alternate manner, the steam in one while the water is in the other. The extractor A contains two concentric compartments A1, A2 of equal capacity; each is provided with a lid at the top and a door at the mottom, a. common perforated floor b, and heating coils c, c1 into which steam can be admitted from a pipe fitted with a threeway cock q. Steam generated in a boiler E, situated below the extractor, is conducted by the branched pipe l to either compartment ; the contents of the extractor are withdrawn through pipe v. Low pressure can be maintained throughout the system by means of a pump D, which is in communication through pipe m with a tank C, a condenser B, and both compartments of the extractor. The pipe m is led through the tank C, which is fitted with a float-actuated valve x<1> and a heating coil y. The contents of the tank C can be transferred to the extractor by pipe r. A regulator f is arranged to actuate simultaneously the three-way cock q on the heating coil pipe and the three-way cock k on the vacuum steam pipe. In operating the apparatus, the extractor is charged to the top with raw material and with water to the level n1. the steam is then admitted into the heating coil c of the inner compartment A1. As the cock k has been set to prevent escape of steam from this compartment, the pressure increases therein and depresses the water level, when the regulator f actuates the cocks k, q to transfer the steam admission into the heating coil c1 of the outer compartment A2 and at the same time to transfer the vacuum connection through pipe m from the outer to the inner compartment. In this way, a continuous interchange of water takes place between the two comparments; whilst during the time that a compartment is not filled with water, steam is admitted from pipe l by the uncovering of either of the pipes l1, l2. Water evaporated by the coils c, c1, as well as surplus steam from the boiler E, is condensed in the condenser B; and the condensate, together with the heated cooling water, flows to the tank C until the latter is full, when the valve x' closes and operates a signal to indicate that the water in the extractor requires renewal. During the subsequent steeping operations, a concentration of glue liquor approximating to that of the preceding operation is obtained by maintaining the water in contact with the partially exhausted material for an increasingly longer time; this is effected by so arranging the internal pipes E2 of the boiler E, that the active heating surface becomes less as the water level falls with each steeping operation. Specification 156,645 is referred to.