GB291082A - Improvements in method and apparatus for nitrating cellulose - Google Patents

Abstract

291,082. Hercules Powder Co., (Assignees of Milliken, M. G.). May 28, 1927, [Convention date]. Cellulose nitrates.-Cellulose to be nitrated is submerged in a stream of nitrating acid and then passed through a body of nitrating acid in which it. remains submerged until nitration to the desired degree is effected. As shown, cellulose, particularly cotton, is supplied through a hopper f to a perforated cylinder b supported in a casing a. Nitrating acid from a tank passes through a heater or cooler t and enters the hopper f by a nozzle o in amount sufficient to submerge the cotton, further amounts of acid being supplied to the cylinder b by pipes p. A worm c carries the submerged cotton through the cylinder b, and a continuous flow of acid through the casing a is maintained by a pump t, which draws acid through pipes r, s<1>, s, and delivers it to the tank j, to which fresh acid is supplied as required. The valve v is closed except when it is required to drain the casing. The casing is fitted with a ventilation i. The nitrated cellulose is forced through a pipe x and a perforated box 4, Fig. 5, on to a conveyer 5 which carries it beneath an adjustable pressure-roll 8 and an adjustable perforated air-roll 12 supplied from an air-compressor (not shown) with dry air withdrawn from the casing 3; an oscillating plate 7 on the box 4 levels out the layer. The product is removed from the conveyer by a paddle 17 and falls into a submersion chamber 19 supplied with water from a pipe 20, whereafter it is carried away through a flume line for further treatment. The conveyer is cleaned by an acid spray 21 fed with acid by the pump t, and the acid thus fed to the casing 3, together with that removed from the nitrated cellulose, is withdrawn by the pump t through a pipe 23.