Patent · US Expired

Process for the continuous digestion of cellulosic fiber material

US5080755A · kind A · utility

30Cited by
11References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 12, 1989
Grant dateJan 14, 1992
Priority date
Expiry dateOct 12, 2009

Classification

  • Technology area (CPC D)Textiles; Paper
  • CPC primaryD21C11/0021
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

A process for the continuous digestion of cellulosic fiber material is described wherein the material is impregnated with liquid in a closed system comprising a concurrent flow zone and a countercurrent flow zone, the liquid in the concurrent flow zone including black liquor and possibly white liquor and the liquid in the countercurrent flow zone including white liquor. Liquid is withdrawn from the impregnation system at a point located between the concurrent flow zone and the countercurrent flow zone. Besides white liquor a predetermined amount of black liquor is added to the countercurrent flow zone in order to obtain a high liquid to wood ratio in the inlet of the digester.

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