Patent · US Expired

Method for the treatment of pulp with liquid

US4705600A · kind A · utility

12Cited by
10References
19Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 24, 1985
Grant dateNov 10, 1987
Priority date
Expiry dateJun 24, 2005

Classification

  • Technology area (CPC D)Textiles; Paper
  • CPC primaryD21C9/02
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A method for the treatment of a suspension, such as pulp, with one or more treatment liquids in a manner that maximizes treatment efficiency and minimizes heat loss. The pulp flows in a flow path confined to a given web thickness, and has first and second opposite sides. Treatment liquid is added to the first side of the flow path at spaced predetermined points along its length. Liquid displaced by the treatment liquid is withdrawn from the second side of the flow path at substantially the predetermined points. The displaced liquid at the first predetermined point along the flow path consists essentially of original suspension liquid, while the liquid fraction of the pulp past the last predetermined point of the flow path is composed mainly of treatment liquid added at the last predetermined point. Treatment can be accomplished at super-atmospheric pressure and at a temperature above 100.degree. C. The web thickness is between about 50-500 mm., and the pulp concentration is between about 7-15 percent and is maintained substantially constant throughout treatment.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.