Patent GB-675660-A (GB)
Title: A process of purifying wool and simultaneously obtaining fatty acids and other substances contained in raw wool, and apparatus for carrying out such process
IPC: D01B3/08
Filed: 1948-08-23
Abstract: <PICT:0675660/III/1> Raw wool is purified and fatty acids, wool grease and inorganic impurities simultaneously obtained by extracting the wool in the cold with nitrated kerosene alone or in admixture with other extracting agents, the nitrated kerosene being prepared by mixing the kerosene with a small quantity of strong nitric acid, leaving at rest for several days, draining off the nitrated kerosene and washing it with a weak solution of an alkali.  The nitrated kerosene may be repeatedly passed through the raw wool, and the same nitrated kerosene may be used for several batches of raw wool.  The raw wool may be preliminarily immersed in one batch of the nitrated kerosene to remove the coarsest impurities and then treated in a further batch of the nitrated kerosene.  After wringing, the wool may be washed one or more times in cold water. The water may be removed by centrifuging and the wool then dried, preferably in hot air at 50 DEG -60 DEG C., the used nitrated kerosene may be regenerated by vacuum distillation under a vacuum of about 10 mm. of mercury and at a temperature of about 150 DEG C.  The nitrated kerosene may be prepared by adding to a litre of kerosene of boiling range 100-350 DEG C, 3 to 5 ccs. of nitric acid of 40-45 DEG  B<\>ae, agitating the mixture and then leaving to rest for at least 7 days.  The nitrated kerosene is then drained off deposited nitrogenous matter and washed with sodium bicarbonate solution. In a suitable plant for effecting the process, the raw wool in a perforated basket 3 is placed in a preliminary cleaning vessel 1, filled with the nitrated kerosene, provided with a false bottom 5 the apertures of which are closed or opened by a further perforated movable bottom 6.  The wool may be compressed by a piston 8 to expel coarse impurities which fall through the bottoms 5 and 6 in register.  The bottom 6 is then moved to close the apertured bottom 5 and the wool transferred to a second cleaning vessel provided with a similar perforated double bottom 15, 16. The nitrated kerosene is continuously circulated through the wool by a pump 14, conduit 17 and distributing ring 18.  The wool is then conveyed through wringer rollers 20 to a first water tank 24, the expressed impurities and solvent being returned from a trough 21 to the lower part of the vessel for re-use.  A second water tank 25 is shown and both are provided with perforated bottoms through which cold water is supplied from a conduit 26.  A conveyer worm 27 and a raking wheel 31 are arranged in the tanks respectively; wringer rollers 29, 33 are also provided, the former having a collecting trough 32 for the expressed material.  The wool is finally conveyed to a centrifuge 35 to remove excess of the remaining water before being dried in hot air at 50-60 DEG C.  In a modification, the worm 27 and raking wheel 31 may be replaced by a single rotatable shaft mounting a series of impeller blades inclined so as to impart movements to the wool from the left to the right hand side of the tanks.  Specification 675,674 is referred to.