GB939604A - Digesters - Google Patents

Abstract

939,604. Endless conveyers. BAUER BROS. CO. Nov. 25, 1960 [Nov. 30, 1959], No. 40695/60. Class 78 (1). [Also in Group XIII] A continuous treatment digester of the moving conveyer type consists of a cylindrical tube closed at both ends, one end having a closure unit with an inwardly facing concave surface, a conveying means in the tube to conduct fragmentary fibrous material continuously along the tube from an inlet to the concave surface and then back along the tube to an outlet, and flights on the conveying means to receive the fragmentary material in loosely packed form, each flight having a leading inclined edge that leads the flight into the turn at the end with the closure unit. The digester as shown has an inlet 29 and an outlet 36 in the tube shell 10 and is filled with a quantity of cooking liquor below the levels of the inlet and outlet. A rotary valve 33 admits predetermined metered quantities of fibrous material, which is conducted down the tube by the continuous conveyer which consists of a chain or chains 19 with flights 26. The material is turned through 180 degrees in an arcuate passage 35 formed by the concave surface 16, and conducted up the tube to the outlet 36 and a rotary outlet valve 38. The tube 10 is partitioned off into upper and lower flight passages 24 and 25 respectively, by a hollow central partition 23. It is around the end of this partition 23 that the leading inclined edges of the flights 26 turn, so keeping the volume between two flights approximately equal in the flight passages 24, 25 and the arcuate passage 35. The closure unit 14 constitutes a false bottom to the tube 10, and consists of a cylindrical portion 15 slidably mounted in the tube 10 and a hemispherical part forming the concave surface 16. The cylindrical part 15 extends beyond the hemispherical part and provides rotary bearings for a transverse shaft 17 on which are mounted discs 18 providing guides and mountings for the chains 19. The chains are driven by sprockets 21 mounted on a transverse shaft 22 driven by an external means not shown. A compression spring 44 is based on a plate 45 forming part of a stuffing box 43 on the bottom of the closure cap 13, through which passes a rod 42 attached to the closure unit 14. The spring reacts against a stop 46 adjustably mounted with a nut 47 on the end of the rod 42, and keeps the chains 19 under tension. Specification 939,271 is referred to.