Abstract: A paper web forming apparatus essentially comprising two wires which move together with stock which is held therebetween and a plurality of wire supporting members for supporting the wires, each of the wire supporting members forming a wedge-shaped space as defined between the wire surface and the wire supporting member, wherein the wedge-shaped space is so designed that the width as measured therebetween decreases as seen in the direction of movement of the wires.
Type:
Grant
Filed:
June 12, 1989
Date of Patent:
March 12, 1991
Assignee:
Research Association for Pulp and Paper Technology
Abstract: A method and apparatus are disclosed for concentrating an alkaline waste liquor containing sulfur compounds, the so-called black liquor, which is discharged from a step of Kraft-cooking wood fibers, in order to recover the cooking chemicals from said waste liquor, characterized in that CO.sub.2 gas and/or a gas containing CO.sub.2 gas is added to said waste liquor as a boiling-point-lowering agent, viscosity-lowering agent and solidification promoter, after a step of oxidizing said waste liquor and in or prior to one or more stages during the step of concentrating said waste liquor. Also disclosed is an apparatus for concentrating an alkaline waste liquor containing substantially no sulfur compounds (i.e.
Type:
Grant
Filed:
September 21, 1987
Date of Patent:
March 27, 1990
Assignee:
Research Association of Pulp and Paper Technology