Patent · US Expired

Process for operating a digester

US5591303A · kind A · utility

1Cited by
6References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 22, 1995
Grant dateJan 7, 1997
Priority date
Expiry dateMar 22, 2015

Classification

  • Technology area (CPC D)Textiles; Paper
  • CPC primaryD21C7/14
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

In a pulp digester for continuous cooking under raised pressure and temperature of fiber material in a vertical digester (1), input of fiber material and cooking liquid takes place at the top of the digester, withdrawal of spent cooking liquor is carried out from at least one digester screening arrangement (1D) between the top and the bottom of the digester, and fiber material is fed out from the bottom (1C) of the digester, and at least one screening arrangement (2) in the lower half of the digester, wherein at least one of said screening arrangements (1, 2) has at least one screen element (2A) of which the main configuration is of angular shape, preferably rectangular, most preferred square, having a screen face (3A) of which the total area is less than 1 m.sup.2, and which is attached to the digester wall (1A) in a manner to form a sealed volume (V) from which liquid only can be supplied and withdrawn via said screen face (3A) and an inlet and outlet (15) respectively which outlet penetrates the digester wall (1A).

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