EP0492039A1 - Pneumatischer Reaktor zum Ozonbleichen von Zellstoff - Google Patents

Pneumatischer Reaktor zum Ozonbleichen von Zellstoff Download PDF

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Publication number
EP0492039A1
EP0492039A1 EP91109775A EP91109775A EP0492039A1 EP 0492039 A1 EP0492039 A1 EP 0492039A1 EP 91109775 A EP91109775 A EP 91109775A EP 91109775 A EP91109775 A EP 91109775A EP 0492039 A1 EP0492039 A1 EP 0492039A1
Authority
EP
European Patent Office
Prior art keywords
gas
ozone
discharge
pulp
recited
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Withdrawn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
EP91109775A
Other languages
English (en)
French (fr)
Inventor
Joseph R. Phillips
Brian F. Greenwood
Michael D. Fahey
Stephen J. Dunn
Jian Jiang
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.)
Kamyr Inc
Original Assignee
Kamyr 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 Kamyr Inc filed Critical Kamyr Inc
Publication of EP0492039A1 publication Critical patent/EP0492039A1/de
Withdrawn legal-status Critical Current

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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
    • 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
    • D21C9/153—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications with ozone

Definitions

  • a method for delignifying comminuted cellulosic fibrous material with ozone containing gas comprises the steps of continuously and sequentially: (a) Fluffing the material. (b) Adding a gas, containing an effective amount of ozone to effect delignification, to the material. (c) Pneumatically conveying the material in a first path for at least a few seconds, the ozone reacting with the material during conveyance to effect delignification. (d) Separating the majority of gas from the material at the end of the first path. And, (e) maintaining the material in a generally static state for at least a few seconds.
  • the pulp In the fluffer discharge 17 the pulp is entrained in a stream of gas exiting from the gas moving means (blower) 20, and the mixture of ozone containing gas and pulp is thereby pneumatically conveyed in a first path, defined by conduit 21.
  • the length of the path defined by conduit 21, and the speed of pneumatic conveyance, are gauged so that the pulp is exposed to the ozone containing gas for at least a few seconds, typically about 15 seconds or less, e.g. about four seconds. Since the pulp in the conduit 21 is fluffy, having a great surface area, and in view of the fact that it is intimately surrounded by the ozone containing gas, being thoroughly mixed therewith without any mechanical elements during the conveyance, the delignifying reaction will be quick and effective.
  • a gas/pulp separator -- such as the cyclone 22 -- is provided, the cyclone 22 having a gas discharge 23 and a pulp discharge 24.
  • the cyclone 22 allows the charge of ozone to be "slipped", that is it ensures that ozone is not exposed in relatively high concentration to the pulp for such a long period of time that some of the pulp cellulose might be attacked by the ozone.
  • the vast majority of the spent gas -- which includes oxygen and unreacted ozone as the primary constituents -- is discharged in conduit 23 for exhaust or recycle, while the comminuted cellulosic fibrous material -- which has little -- though some -- gas remaining therein is discharged at 24.
  • a portion of the recycled gas is reused as carrier gas through line 34 into line 35. The remaining portion of recycle gas (nearly equal to supply gas) is recycled to an ozone generation, or if not economical for ozone generation it is exhausted.
  • the discharge 24 from cyclone 22 is preferably into a vessel, such as a substantially vertical axis retention tube 25.
  • a vessel such as a substantially vertical axis retention tube 25.
  • the fluffed pulp is maintained in a generally static condition (although there is movement downwardly in the tube) for at least a few seconds, e.g. for about ten seconds (but typically less than a minute), so that a delignifying reaction with a small amount of residual ozone has an opportunity to move toward completion.
  • the pulp is discharged by air lock 26 into another sequence of equipment substantially identical to that just described.
  • the air lock 26 preferably is a conventional low pressure feeder, such as used commonly in the pulp and paper art for feeding wood chips to a low pressure steaming vessel.
  • any number of sequences of equipment as illustrated in FIGURE 1 can be provided.
  • a third set of equipment may be provided, which is illustrated in FIGURE 1 by the same reference numerals as for the first set of equipment only preceded by a "2". That is the fluffed material is discharged from air lock 126 into conduit 221 and pneumatically conveyed therein by the blower 220.
  • Ozone containing gas (typically oxygen) from source 18 is provided to the blower 220 to provide a portion of the gas needed to pneumatically convey the fluffed pulp to the third separator 222.
  • the majority of the conveying gas is spent gas from line 21 which is passed through line 34 to line 35.
  • Fresh ozone/oxygen mixture is added to line 35.
  • the gas from gas discharge 223 to the third separator 222 is fed back as the feed gas to the blower 120 and includes ozone therein, while the material is discharged from cyclone 222 to retention tube 225 and then into air lock 226.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)
EP91109775A 1990-12-27 1991-06-14 Pneumatischer Reaktor zum Ozonbleichen von Zellstoff Withdrawn EP0492039A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US63334790A 1990-12-27 1990-12-27
US633347 1990-12-27

Publications (1)

Publication Number Publication Date
EP0492039A1 true EP0492039A1 (de) 1992-07-01

Family

ID=24539279

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91109775A Withdrawn EP0492039A1 (de) 1990-12-27 1991-06-14 Pneumatischer Reaktor zum Ozonbleichen von Zellstoff

Country Status (8)

Country Link
EP (1) EP0492039A1 (de)
JP (1) JPH04245989A (de)
AU (1) AU636766B2 (de)
BR (1) BR9104366A (de)
CA (1) CA2044907A1 (de)
FI (1) FI915947A (de)
NO (1) NO914169L (de)
ZA (1) ZA915144B (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993014860A1 (en) * 1992-01-23 1993-08-05 Kamyr Ab Separation device and process
US5520783A (en) * 1990-10-26 1996-05-28 Union Camp Patent Holding, Inc. Apparatus for bleaching high consistency pulp with ozone
WO1997005327A1 (en) * 1995-07-26 1997-02-13 Beloit Technologies, Inc. Method and apparatus for bleaching pulp with a gaseous bleaching reagent
US5942088A (en) * 1995-07-26 1999-08-24 Beloit Technologies, Inc. Apparatus for bleaching high consistency pulp with a gaseous bleaching reagent

Families Citing this family (2)

* 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
NZ242792A (en) * 1991-05-24 1993-12-23 Union Camp Patent Holding Two-stage pulp bleaching reactor: pulp mixed with ozone in first stage.

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2388933A1 (fr) * 1977-04-27 1978-11-24 Myrens Verksted As Procede et installation pour le traitement d'une matiere volumineuse finement divisee notamment d'une pate fibreuse ou cellulosique
EP0308314A1 (de) * 1987-09-17 1989-03-22 "DEGREMONT" Société dite: Verfahren zur Ozonbehandlung von Lignocellulosematerialien, insbesondere Papiermassen, und Reaktor zum Ausführen des Verfahrens
DE4025616A1 (de) * 1989-08-16 1991-02-21 Andritz Ag Maschf Verfahren zur zerkleinerung von materialien und anlage zu dessen durchfuehrung

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3814664A (en) * 1972-09-11 1974-06-04 Improved Machinery Inc Gaseous reaction apparatus including a peripheral gas receiving chamber

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2388933A1 (fr) * 1977-04-27 1978-11-24 Myrens Verksted As Procede et installation pour le traitement d'une matiere volumineuse finement divisee notamment d'une pate fibreuse ou cellulosique
EP0308314A1 (de) * 1987-09-17 1989-03-22 "DEGREMONT" Société dite: Verfahren zur Ozonbehandlung von Lignocellulosematerialien, insbesondere Papiermassen, und Reaktor zum Ausführen des Verfahrens
DE4025616A1 (de) * 1989-08-16 1991-02-21 Andritz Ag Maschf Verfahren zur zerkleinerung von materialien und anlage zu dessen durchfuehrung

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5520783A (en) * 1990-10-26 1996-05-28 Union Camp Patent Holding, Inc. Apparatus for bleaching high consistency pulp with ozone
WO1993014860A1 (en) * 1992-01-23 1993-08-05 Kamyr Ab Separation device and process
US6004364A (en) * 1992-01-23 1999-12-21 Kamyr Aktiebolag Separation device
WO1997005327A1 (en) * 1995-07-26 1997-02-13 Beloit Technologies, Inc. Method and apparatus for bleaching pulp with a gaseous bleaching reagent
US5942088A (en) * 1995-07-26 1999-08-24 Beloit Technologies, Inc. Apparatus for bleaching high consistency pulp with a gaseous bleaching reagent

Also Published As

Publication number Publication date
AU636766B2 (en) 1993-05-06
FI915947A0 (fi) 1991-12-18
JPH04245989A (ja) 1992-09-02
BR9104366A (pt) 1992-08-18
NO914169D0 (no) 1991-10-23
ZA915144B (en) 1992-05-27
NO914169L (no) 1992-06-29
CA2044907A1 (en) 1992-06-28
FI915947A (fi) 1992-06-28
AU7911691A (en) 1992-07-02

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