EP0295180A3 - Process for bleaching or delignification of a cellulose pulp with oxygen, and plant for carrying out the process - Google Patents

Process for bleaching or delignification of a cellulose pulp with oxygen, and plant for carrying out the process Download PDF

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Publication number
EP0295180A3
EP0295180A3 EP88401393A EP88401393A EP0295180A3 EP 0295180 A3 EP0295180 A3 EP 0295180A3 EP 88401393 A EP88401393 A EP 88401393A EP 88401393 A EP88401393 A EP 88401393A EP 0295180 A3 EP0295180 A3 EP 0295180A3
Authority
EP
European Patent Office
Prior art keywords
oxygen
suspension
bubbles
paste
speed
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP88401393A
Other languages
German (de)
French (fr)
Other versions
EP0295180A2 (en
Inventor
Robert Lee
Derek Hornsey
Arthur S. Perkins
Jack A. Davidson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Air Liquide Canada Inc
Original Assignee
Air Liquide Canada Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Air Liquide Canada Inc filed Critical Air Liquide Canada Inc
Publication of EP0295180A2 publication Critical patent/EP0295180A2/en
Publication of EP0295180A3 publication Critical patent/EP0295180A3/en
Withdrawn legal-status Critical Current

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/10—Bleaching ; Apparatus therefor
    • D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)

Abstract

Dans ce procédé continu de blanchiment ou de délignification d'une pâte cellulosique par l'oxygène, on fait passer la pâte, sous la forme d'une suspension aqueuse, dans un conduit diffuseur et mélangeur (123), à une vitesse à laquelle cette pâte se comporte comme un liquide turbulent et, ensuite, dans une cuve de rétention (137), à une vitesse à laquelle la suspension prend un écoulement de type piston. Un mélange d'oxygène-vapeur d'eau est diffusé à travers une paroi microporeuse qui forme une interface avec la suspension circulant dans le conduit, pour former une masse de petites bulles d'oxygène où la vapeur se sépare par condensation en apportant de la chaleur à la suspension et en laissant l'oxygène sous la forme de bulles plus petites qui se dispersent dans tout le volume de la suspension, en présentant une aire de surface totale considérablemetn supérieure à celles des bulles qui résulteraient de l'injection d'oxygène seul à travers la même paroi microporeuse dans les même conditions. Les bulles d'oxygène restent dispersées dans tout le volume de la suspension lorsque cette dernière prend un écoulement de type piston, pour donner à l'oxygène le temps d'exercer son effet de blanchiment. L'invention concerne également une installation pour la mise en oeuvre du procédé. In this continuous bleaching or delignification process of a cellulosic paste by oxygen, the paste is passed under the form of an aqueous suspension, in a diffuser and mixer duct (123), at a speed at which this paste behaves like a liquid turbulent and then in a holding tank (137) at a speed at which the suspension takes a piston type flow. A mix oxygen-water vapor is diffused through a microporous wall which forms an interface with the suspension circulating in the conduit, to form a mass of small oxygen bubbles where the vapor is separated by condensation by bringing heat to the suspension and leaving oxygen in the form of smaller bubbles which disperse in the entire volume of the suspension, presenting a surface area considerably greater than the bubbles which result from injecting oxygen alone through the same wall microporous under the same conditions. The oxygen bubbles remain dispersed throughout the volume of the suspension when the latter takes a piston type flow, to give oxygen time to exert its whitening effect. The invention also relates to a installation for implementing the process.

EP88401393A 1987-06-08 1988-06-08 Process for bleaching or delignification of a cellulose pulp with oxygen, and plant for carrying out the process Withdrawn EP0295180A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CA539056 1987-06-08
CA 539056 CA1300322C (en) 1987-06-08 1987-06-08 Method of bleaching or delignification of cellulose pulp with oxygen

Publications (2)

Publication Number Publication Date
EP0295180A2 EP0295180A2 (en) 1988-12-14
EP0295180A3 true EP0295180A3 (en) 1989-10-11

Family

ID=4135839

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88401393A Withdrawn EP0295180A3 (en) 1987-06-08 1988-06-08 Process for bleaching or delignification of a cellulose pulp with oxygen, and plant for carrying out the process

Country Status (5)

Country Link
EP (1) EP0295180A3 (en)
JP (1) JPH0299681A (en)
AU (1) AU613952B2 (en)
CA (1) CA1300322C (en)
FR (1) FR2617877B1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2046717A1 (en) * 1991-02-06 1992-08-07 Beloit Technologies, Inc. Method and apparatus for treating fibrous materials with a gaseous reagent
SE469398B (en) * 1991-11-06 1993-06-28 Sunds Defibrator Ind Ab HEATING DEVICE FOR EXAMPLE OF CELLULOSAMASSA THEREOF APPLIED BY A MULTIPLE, SCRUBLED LOCATION, TAKEN IN A TRANSMISSION WALL
US5690786A (en) * 1991-11-26 1997-11-25 Air Products And Chemicals Inc. Process for the treatment of pulp with oxygen and steam using ejectors
US5372679A (en) * 1992-06-08 1994-12-13 Air Products And Chemicals, Inc. Reactor system for treating cellulosic pulp at a constant upward flow velocity
EP0647466A3 (en) * 1993-10-08 1996-01-17 Akzo Nobel Nv Cellulosic membranes.

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4177105A (en) * 1973-05-22 1979-12-04 Kamyr, Incorporated Apparatus for delignifying and bleaching cellulose pulp
EP0106460A1 (en) * 1982-09-30 1984-04-25 The Black Clawson Company Improved method and apparatus for oxygen delignification
EP0226495A1 (en) * 1985-11-15 1987-06-24 Canadian Liquid Air Ltd Air Liquide Canada Ltee Process and apparatus for bleaching paper pulp

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4177105A (en) * 1973-05-22 1979-12-04 Kamyr, Incorporated Apparatus for delignifying and bleaching cellulose pulp
EP0106460A1 (en) * 1982-09-30 1984-04-25 The Black Clawson Company Improved method and apparatus for oxygen delignification
EP0226495A1 (en) * 1985-11-15 1987-06-24 Canadian Liquid Air Ltd Air Liquide Canada Ltee Process and apparatus for bleaching paper pulp

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
JOURNAL OF THE TECHNICAL ASSOCIATION OF THE PULP AND PAPER INDUSTRY, vol. 64, no. 6, juin 1981, pages 87-90, Atlanta, Georgia, US; P.J. KLEPPE: "Oxygen/alkali delignification at medium consistency. Mill-scale trials to commercial installation" *

Also Published As

Publication number Publication date
JPH0299681A (en) 1990-04-11
FR2617877A1 (en) 1989-01-13
AU2202188A (en) 1990-06-28
FR2617877B1 (en) 1995-01-06
EP0295180A2 (en) 1988-12-14
CA1300322C (en) 1992-05-12
AU613952B2 (en) 1991-08-15

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