Andritz Inc.

Patrick J Sullivan

C Bertil Stromberg

Keith Vogel

John F Bolles

Brian F Greenwood

Kaj Henricson

Richard O Laakso

A method for converting a vapor phase continuous digester to a hydraulic digester including the steps of: operating the vapor phase digester in a vapor phase mode wherein a chip slurry enters the vessel of the digester through a lower chip inlet port, moves up through a top separator, discharges from an upper chip discharge chute of the separator to an upper vapor region of the vessel and falls to a liquor filled region of the vessel; ceasing the flow of the chip slurry to the separator; establishing a chip slurry flow path to an upper portion of top separator, and filling the vessel with liquor and chips such that the chip discharge chute is immersed in liquor.

Method for converting a digester for use as a gas phase and hydraulic phase continuous digester

A method for adding cooking liquor into a vapor phase continuous digester for producing chemical cellulose pulp from cellulose chips including: introducing a slurry of the cellulose chips from a feed system to an inverted top separator in a top vapor phase section of the digester; distributing the slurry of the cellulose chips from the top separator into the vapor phase section of the digester; passing liquor through a conduit included with the drive shaft assembly of the top separator, and introducing the liquor from the conduit into the slurry as the slurry flows through the top separator or is distributed from the separator into the vapor phase section.

Gas phase continuous digester having an inverted top separator with liquor injection

A continuous digester for producing chemical cellulose pulp from cellulose chips including: a digester vessel with an upper section attached to a top separator and said vessel at least partially filled with the cellulose chips and a liquor; a top separator at least partially in said upper section having a lower chip inlet port, a chip conveyor, a screen adjacent the conveyor, an upper chip discharge chute, and a liquor outlet facing a side of the screen opposite to the conveyor, and a chip inlet conduit extending into the vessel and having a first operational mode in fluid communication with the chip inlet port and a second operational mode in which the chip inlet conduit discharges directly into the vessel.

Top separator for gas phase and hydraulic phase continuous digesters and method for converting digester

A continuous digester is disclosed for producing chemical cellulose pulp from cellulose chips, comprising: a continuous digester vessel having a lower section filled with the cellulose chips and an upper gas filled section; an inverted separator at least partially in said upper section which introduces chips and liquid into said digester vessel and separates some of the liquid from the chips, wherein said separator includes a drive shaft connected to a conveyor, and a liquid discharge port proximate to the drive shaft and arranged proximate to a chip discharge of the separator.

A method is disclosed for extracting liquor from a cellulose slurry for a continuous digester comprising the steps of: providing the cellulose slurry of liquor and chips of cellulose fiber material to a separator; extracting a first stream of liquor from the separator; extracting a second stream of liquor from the separator, where the second stream has an effective alkali (EA) concentration greater than the EA concentration of the first steam; outputting the first stream from the separator and outputting the second stream from the separator separately from the second stream, and outputting a condensed slurry from the separator to a digester vessel.

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Argyle, NY, United States of America

Patrick J Sullivan