US 6,280,567 B1 · System and method for treatment of cellulose-containing material prior to pulp digestion

Abstract

The invention relates to a process system and a method for preliminary treatment of disintegrated cellulose-containing material, preferably wood chips, prior to pulp digestion. The process system and the method according to the invention make use of a process vessel intended to function both as a so-called chip bin and as a pre-impregnation vessel. The characteristics of the invention are that a sloping steaming vessel is arranged downstream of the process vessel for the purpose of separating an excess of pre-impregnation liquid from the pre-impregnated cellulose-containing material, that the sloping steaming vessel is arranged for supplying steaming vapor which preferably has been generated by flashing of extraction liquor from a pulp digester, and that the sloping steaming vessel is connected to a chip chute communicating with a condenser for connection to a system for managing foul-smelling process gases. The invention can be applied in the production of pulp which is intended for paper manufacture or other applications where cellulose fibers are used.

Claims7

Dependent claims

A method for preliminary treatment of a disintegrated cellulose-containing material prior to pulp digestion, comprising:

(a) providing a pressure in a process vessel that is substantially similar to an atmospheric pressure;
(b) pre-impregnating the cellulose-containing material in the process vessel with a sulphur-containing alkaline liquor, the cellulose-containing material flowing in a downstream flow direction;
(c) feeding the pre-impregnated cellulose-containing material to a sloping steaming vessel, the sloping vessel being downstream of the process vessel;
(d) separating off an amount of the liquor from the cellulose-containing material in the sloping steaming vessel, the amount being a substantial portion of a total amount of the liquor to be conveyed to a chemical recovery unit;
(e) steaming the pre-impregnated cellulose-containing material in the sloping steaming vessel;
(f) passing the liquor from step (d) through a heat exchanger;
(g) dividing the liquor from step (f) into a first subsidiary stream and a second subsidiary stream;
(h) flashing an extraction liquor from pulp digestion to generate a steaming vapor for steaming in step (e);
and
(i) collecting and condensing foul-smelling gases from steps (b) and (e).

7 more elements

A system for a preliminary treatment of a disintegrated cellulose-containing material prior to a pulp digestion, comprising:

a process vessel for pre-impregnating the cellulose-containing material disposed therein with a pre-impregnation liquid, the process vessel being operable at a pressure that is substantially similar to an atmospheric pressure;
a sloping steaming vessel in fluid communication with and downstream of the process vessel for steaming the pre-impregnated cellulose-containing material;
an excess conduit in operative engagement with the steaming vessel for separating excess pre-impregnation liquid from the pre-impregnated cellulose-containing material;
a high-pressure feeder, in fluid communication with the steaming vessel, attached to a pulp digester;
a flashing mechanism in operative engagement with the pulp digester for flashing an extraction liquor received from the pulp digester to generate a steaming vapor, the steaming vessel in fluid communication with the flash mechanism for receiving the steaming vapor therefrom;
a chip chute in operative engagement with the steaming vessel;
and
a condenser in fluid communication with the chip chute and with a system for managing foul-smelling process gases generated from the process vessel and the sloping steaming vessel.

5 more elements

Dependencies are inferred from the claim text.

System and method for treatment of cellulose-containing material prior to pulp digestion

Life of this patent

System and method for treatment of cellulose-containing material prior to pulp digestion

Life of this patent

Abstract

Claims7