GB672302A

GB672302A - Process and apparatus for ageing alkali cellulose

Info

Publication number: GB672302A
Application number: GB3094749A
Authority: GB
Original assignee: ROBERT PEPPERRELL KING
Current assignee: ROBERT PEPPERRELL KING
Priority date: 1949-12-02
Filing date: 1949-12-02
Publication date: 1952-05-21

Abstract

Alkali-cellulose is treated to loosen, blend, and fluff the fibres into the form of crumbs, and these are continuously spread uniformly across the top of a vertical ageing-tower of uniform cross-sectional area throughout its height; the tower is maintained full of alkali- <PICT:0672302/IV (a)/1> <PICT:0672302/IV (a)/2> <PICT:0672302/IV (a)/3> <PICT:0672302/IV (a)/4> cellulose crumbs which are allowed to settle by gravity; at the bottom of the tower the crumbs are continuously engaged and picked so as to be removed uniformly from across the bottom area of the tower and so as to cause all the crumb particles to settle at the same uniform rate. All of the crumb particles thus remain in the tower for the same length of time while passing from the top to the bottom. The tower may be provided with a jacket for controlling the temperature of ageing. Air or inert gas may be passed upwardly through the tower. As shown in Fig. 1, the tower 10 comprises an inner shell 11 and an outer shell 12 spaced therefrom to form a jacket 26. A conical discharge hopper 16 terminates in a discharge duct 17 having a ball-valve 18 with rotating vanes 19 adapted to discharge the crumbs at a controlled rate while maintaining a vapour seal. Air or inert gas may be introduced through annular passage 20 and openings 22. Temperature-control fluid may be introduced through duct 25 to the jacket 26. A discharge picker assembly 35 extends across the bottom of the tower. This assembly comprises several shafts 38 (Fig. 2), carrying picker fingers 39. The shafts have worm wheels 71 meshing with worms on shaft 41. Preferably, alternate shafts 38 rotate in opposite directions. The picker fingers 39 may take the form of crossed rods, or semi-circular segmental members 39b (Fig. 4), or discs 39c (Fig. 6). The discs 39c are provided with pins 45. From the discharge duct 17 of the ageingtower, the alkali-cellulose may be passed to a shredder and thence to a continuously-acting xanthating drum.