GB274814A - Process and apparatus for the continuous manufacture of cellulose acetate - Google Patents

Abstract

274,814. Soc. Chimique des Usines du Rh¶ne. July 26, 1926, [Convention date]. Continuous-discharge apparatus with moving containers.-Cellulose acetate is made by passing the reagents continuously through apparatus of small diameter compared with its length and rotating about an inclined axis. The temperature at different zones may be regulated by sprinkling the outside of the apparatus with hot or cold water. The diameter of the apparatus may be variable so as to modify the speed of the travel of the reagents at different parts of the apparatus, and material may be caused to accumulate at desired points by arranging perforated discs or continuous or discontinuous helicoidal partitions in the apparatus, and near these points, energetic stirring may be affected by means of straight or bent rods arranged radially or at some distance from the wall and carried by the wall near the inlet end, and in the second part of the apparatus where the mass is of a pasty consistency paddles may be employed. Baffles may be provided independent of the wall and carried by a central shaft, and these may be inclined to the axis of the apparatus to assist in causing the reagents to travel. The rods and paddles may be carried by a central shaft instead of by the wall and a heating or cooling fluid may be circulated through the stirring devices. Several of the inclined rotary apparatus may be arranged in conjunction, part of the process being carried out in each; their inclinations and rates of rotation may be different, and fresh reagents may be added at the various stages of the operation. The apparatus may consist of a tapered cylinder 1 Fig. 1, rotating about a slightly inclined axis, with sprays 8 directed upon its outer surface. Reagents are admitted at 5, 6, and 7 and the finished product is withdrawn at 9. In a modification, Fig. 2, stirring rods 10, paddles 11 and 13 and helicoidal paddles 12 are carried by the wall of the reaction chamber, and a disc 16 with a central opening causes an accumulation of material at one point. Baffles 14 and 15 inside the shell are provided for ensuring a regular advance. of the reaction mass. Specifications 231,837, [Class 2 (ii), Cellulose &c.], and 270,656 are referred to.