GB1294762A - Improvements in and relating to a method of and apparatus for forming a sheet or web of material from solids in suspension - Google Patents

Abstract

1294762 Papermaking NEYRPIC-BMB 27 Jan 1970 [27 Jan 1969] 3956/70 Heading D2A Apparatus for forming a sheet from a suspension comprises a chest, an inlet conduit for supplying suspension to the chest, and an outlet conduit having a bottom wall which is downwardly inclined in the direction of flow of suspension along the outlet conduit and is formed at least in part by an endless filter screen movable via downward direction; and a top wall which is so downwardly inclined that the section of the outlet conduit decreases towards the downstream end, the inclination of the filter screen being adjustable. As shown, stock is fed at 1 to distributor 2, tubes 3 and to stock chest 4. Movable screen 8 is held in shape by rods 9, which may or may not rotate, and are adjustable in position. The side. walls of the chest 4 may be movable to adjust the width of sheet formed. Catch pan 14 is positioned under the wire. The top of tank 5 may be closed, and the pressure above the stock varied. The catch pan may be replaced by a suction box with variable suction. The profile of the screen is preferably such that the head of suspension is represented by H s =H 0 )+KS<SP>α</SP> where H 0 is the drainage head at the point where filtration starts; H s is the drainage head at a distance S from the point where drainage starts, K is a constant which depends on the drainage parameters, and α is an exponent which is I for incompressible solids and greater than 1 for compressible solids.