EP0721526B1 - Method and apparatus for dewatering of a fibre suspension - Google Patents

Method and apparatus for dewatering of a fibre suspension Download PDF

Info

Publication number
EP0721526B1
EP0721526B1 EP94929079A EP94929079A EP0721526B1 EP 0721526 B1 EP0721526 B1 EP 0721526B1 EP 94929079 A EP94929079 A EP 94929079A EP 94929079 A EP94929079 A EP 94929079A EP 0721526 B1 EP0721526 B1 EP 0721526B1
Authority
EP
European Patent Office
Prior art keywords
dewatering apparatus
fractionator
outlet
fraction
suspension
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.)
Expired - Lifetime
Application number
EP94929079A
Other languages
German (de)
French (fr)
Other versions
EP0721526A1 (en
Inventor
Kent Strid
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.)
Kvaerner Pulping AS
Original Assignee
Kvaerner Pulping AS
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 Kvaerner Pulping AS filed Critical Kvaerner Pulping AS
Publication of EP0721526A1 publication Critical patent/EP0721526A1/en
Application granted granted Critical
Publication of EP0721526B1 publication Critical patent/EP0721526B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21D—TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
    • D21D1/00—Methods of beating or refining; Beaters of the Hollander type
    • D21D1/20—Methods of refining
    • D21D1/40—Washing the fibres
    • 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
    • D21C9/18—De-watering; Elimination of cooking or pulp-treating liquors from the pulp
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
    • D21F1/00—Wet end of machines for making continuous webs of paper
    • D21F1/66—Pulp catching, de-watering, or recovering; Re-use of pulp-water

Definitions

  • the present invention concers a method and an apparatus for the conversion of a fibre suspension and particularly for increasing the output of a dewatering apparatus especially for recycled fibre pulp.
  • the present invention concerns a method according to claim 1 and an apparatus according to claim 2.
  • an alternative method is proposed, wherein the filtrate from a dewatering apparatus is treated in a fractionator, where fractioning takes place in liquid, and wherein the fractions from the fractionator are selectively introduced into the dewatered fraction flow from the dewatering apparatus.
  • this can be accomplished in that a fractionator, wherein fractioning takes place in liquid, is connected to a filtrate outlet of a dewatering apparatus, and that fraction outlets of the fractionator lead to a dewatered fraction outlet of the dewatering apparatus.
  • 1 designates any dewatering apparatus, herein shown as a so-called thin film washer of the kind described in Swedish Patent Application No. 9303192-0, filed September 30, 1994 and entitled "Apparatus for washing of fibre suspension”.
  • Diluted recycled fibre pulp (about 1%) is introduced therein through an inlet 2.
  • Water is pressed out of the pulp through a perforated drum 3, and the dewatered pulp (about 8%) is removed from the drum by means of a roller 4 and a scraper 5 and is discharged through an outlet conduit 6.
  • the pressed out water which contains long fibres, fines as well as fillers, is discharged from a container 7 through an outlet 8.
  • a fractionator 10 fractioning in liquid i.e., an apparatus utilizing the fluid flow phenomenon resulting in that larger particles in a flowing liquid are displaced forwardly in the direction of flow, whereas smaller particles are displaced relatively seen backwards in the direction of flow.
  • a flowing plug of, for instance, a suspension there is formed in a flowing plug of, for instance, a suspension, a fractioning in a diminishing particle size from the front and backwards in the plug.
  • the fractionator shown is of the kind described in Swedish Patent Application No. 9303193-8, filed September 30, 1994 and entitled "Fractionator".
  • Such a fractionator is provided with a rotatable cylindrical drum 11, within which are provided a plurality of cylinders 12, 13, 14, 15 and 16 concentric to the drum.
  • Every second such cylinder is tightly connected in its one end to one end wall of the drum, while flow can take place between the other end of the cylinder and the opposite end wall of the drum.
  • the outlets 18, 19 and 20 are connected to outlet conduits 21, 22, 23, respectively, which in turn and in a non-shown manner are connected to the outlet conduit 6 of the dewatering apparatus.
  • the outlet conduits lead to non-shown tanks for the different fractions, wherefrom the fractions may be selectively introduced into the outlet conduit 6 of the dewatering apparatus in order to re-introduce into the concentrated pulp flow present in the outlet conduit 6 selected amounts of selected fractions from the fractionator.
  • the fraction or fractions to be introduced into the outlet conduit 6, as well as the amounts thereof, are determined by sensing the quality of the pulp at the inlet 2 of the dewatering apparatus and/or its outlet 6.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)
  • Treatment Of Fiber Materials (AREA)
  • Drying Of Solid Materials (AREA)
  • Preliminary Treatment Of Fibers (AREA)

Abstract

In a method for the conversion of a fibre suspension, and particularly for increasing the output of a dewatering apparatus especially for recycled fibre pulp, the reject from the dewatering apparatus is treated in a fractionator, where fractioning takes place in liquid, and fractions from the fractionator are selectively introduced into the accept flow from the dewatering apparatus. In an apparatus for practising the method, a fractionator (10) of the kind where fractioning takes place in liquid is connected to the reject outlet (8) of a dewatering apparatus (1), and the fraction outlets (18, 19, 20) of the fractionator lead to the accept outlet (6) of the dewatering apparatus (1).

Description

The present invention concers a method and an apparatus for the conversion of a fibre suspension and particularly for increasing the output of a dewatering apparatus especially for recycled fibre pulp.
With the filtrate from dewatering apparatuses, such as so-called thin film washers, screw presses, disk filters etc., is brought along not only fine particles, such as so-called fines and fillers, but also a relatively large share of valuable fibres (long fibre fraction). It is an economical as well as an environmental desire to be able to recover not only the latter, but also the fine particles to reintroduce them into the process. Hitherto, this has taken place in flotation apparatuses, filters etc.
The present invention concerns a method according to claim 1 and an apparatus according to claim 2.
Now, according to the present invention, an alternative method is proposed, wherein the filtrate from a dewatering apparatus is treated in a fractionator, where fractioning takes place in liquid, and wherein the fractions from the fractionator are selectively introduced into the dewatered fraction flow from the dewatering apparatus. According to the present invention, this can be accomplished in that a fractionator, wherein fractioning takes place in liquid, is connected to a filtrate outlet of a dewatering apparatus, and that fraction outlets of the fractionator lead to a dewatered fraction outlet of the dewatering apparatus.
According to the present invention it is now possible to control the quality of the dewatered fraction of a dewatering apparatus by fractioning the filtrate and supply fractions of the filtrate to the dewatered fraction.
The invention will be further elucidated hereinafter, reference being made to an exemplifying embodiment illustrated in the attached drawing, wherein the sole figure shows a schematic view of an apparatus according to the present invention.
In the drawing, 1 designates any dewatering apparatus, herein shown as a so-called thin film washer of the kind described in Swedish Patent Application No. 9303192-0, filed September 30, 1994 and entitled "Apparatus for washing of fibre suspension". Diluted recycled fibre pulp (about 1%) is introduced therein through an inlet 2. Water is pressed out of the pulp through a perforated drum 3, and the dewatered pulp (about 8%) is removed from the drum by means of a roller 4 and a scraper 5 and is discharged through an outlet conduit 6. The pressed out water, which contains long fibres, fines as well as fillers, is discharged from a container 7 through an outlet 8.
To the outlet 8 is connected the inlet 9 of a fractionator 10 fractioning in liquid, i.e., an apparatus utilizing the fluid flow phenomenon resulting in that larger particles in a flowing liquid are displaced forwardly in the direction of flow, whereas smaller particles are displaced relatively seen backwards in the direction of flow. Thus, there is formed in a flowing plug of, for instance, a suspension, a fractioning in a diminishing particle size from the front and backwards in the plug. The fractionator shown is of the kind described in Swedish Patent Application No. 9303193-8, filed September 30, 1994 and entitled "Fractionator". Such a fractionator is provided with a rotatable cylindrical drum 11, within which are provided a plurality of cylinders 12, 13, 14, 15 and 16 concentric to the drum. Every second such cylinder is tightly connected in its one end to one end wall of the drum, while flow can take place between the other end of the cylinder and the opposite end wall of the drum. Suspension from the outlet 8 of the dewatering apparatus introduced into the centre of the drum through the inlet 9, thus, flows forwards and backwards between the end walls of the drum and simultaneously outwards towards the drum mantle 17, where the fractionator is provided with outlets for several fractions, in the example shown one outlet 18 for short fibres, one outlet 19 for fines and one outlet 20 for fillers, such as ash and clay.
The outlets 18, 19 and 20 are connected to outlet conduits 21, 22, 23, respectively, which in turn and in a non-shown manner are connected to the outlet conduit 6 of the dewatering apparatus. Suitably, the outlet conduits lead to non-shown tanks for the different fractions, wherefrom the fractions may be selectively introduced into the outlet conduit 6 of the dewatering apparatus in order to re-introduce into the concentrated pulp flow present in the outlet conduit 6 selected amounts of selected fractions from the fractionator. The fraction or fractions to be introduced into the outlet conduit 6, as well as the amounts thereof, are determined by sensing the quality of the pulp at the inlet 2 of the dewatering apparatus and/or its outlet 6.

Claims (2)

  1. A method for increasing the yield of a dewatering apparatus for a fiber suspension, particularly for recycled fibre pulp, wherein wherein a fibre suspension is treated in a dewatering apparatus to provide filtrate and dewatered fraction, characterized in that filtrate from the dewatering apparatus is directed to a fractionator, where fractioning takes place in liquid, and that fractions from the fractionator are selectively introduced into a dewatered fraction flow from the dewatering apparatus in dependence on the established quality of said pulp flow.
  2. An apparatus for increasing the output of a dewatering apparatus for a fiber suspension, especially for recycled fibre pulp, including a dewatering apparatus (1) having a suspension inlet (2), a filtrate outlet (8) and a dewatered fraction outlet (6), characterized in that the filtrate outlet (8) of the dewatering apparatus (1) is connected to the filtrate inlet (9) of a fractionator (10), having a plurality of fraction outlets (18, 19, 20) which is of the kind where fractioning takes place in liquid, and that the fraction outlets (18, 19, 20) of the fractionator are connected to the dewatered fraction outlet (6) of the dewatering apparatus (1), sensing means being provided for sensing the suspension quality at the suspension inlet (2) and/or the dewatered fraction outlet (6) of the dewatering apparatus, and control means being provided between the fraction outlets (18, 19, 20) of the fractionator and the dewatered fraction outlet (6) of the dewatering apparatus for controlling the supply of fractions to the dewatered fraction outlet (6) in dependence on the suspension quality sensed by said sensing means.
EP94929079A 1993-09-30 1994-09-29 Method and apparatus for dewatering of a fibre suspension Expired - Lifetime EP0721526B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
SE9303194A SE501772C2 (en) 1993-09-30 1993-09-30 Method and apparatus for increasing the yield upon dewatering of a fiber suspension
SE9303194 1993-09-30
PCT/SE1994/000899 WO1995009268A1 (en) 1993-09-30 1994-09-29 Method and apparatus for dewatering of a fibre suspension

Publications (2)

Publication Number Publication Date
EP0721526A1 EP0721526A1 (en) 1996-07-17
EP0721526B1 true EP0721526B1 (en) 1998-12-02

Family

ID=20391269

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94929079A Expired - Lifetime EP0721526B1 (en) 1993-09-30 1994-09-29 Method and apparatus for dewatering of a fibre suspension

Country Status (11)

Country Link
EP (1) EP0721526B1 (en)
JP (1) JPH09505641A (en)
AT (1) ATE173952T1 (en)
AU (1) AU7826494A (en)
CA (1) CA2172285A1 (en)
DE (1) DE69415035T2 (en)
ES (1) ES2124430T3 (en)
FI (1) FI111276B (en)
NO (1) NO316278B1 (en)
SE (1) SE501772C2 (en)
WO (1) WO1995009268A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2247032A1 (en) * 1996-02-28 1997-09-04 Ryan M. Smith Improved recovery of fine fibers from suspensions containing fibers and contaminants
EP0826819B1 (en) * 1996-08-30 2002-11-20 Voith Paper Fiber Systems GmbH & Co. KG Apparatus for dewatering a fibre suspension
FI106386B (en) 1999-05-03 2001-01-31 Valmet Corp Method and apparatus for recovering fibers from recycled water in a paper mill

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2666598B1 (en) * 1990-09-10 1994-05-27 Escher Wyss Gmbh PROCESS FOR SEPARATING, ESPECIALLY SORTING OR SPLITTING A SUSPENSION OF PAPER PULP.

Also Published As

Publication number Publication date
CA2172285A1 (en) 1995-04-06
FI961452A7 (en) 1996-03-29
DE69415035D1 (en) 1999-01-14
EP0721526A1 (en) 1996-07-17
NO961129D0 (en) 1996-03-20
JPH09505641A (en) 1997-06-03
FI961452A0 (en) 1996-03-29
AU7826494A (en) 1995-04-18
SE501772C2 (en) 1995-05-15
ATE173952T1 (en) 1998-12-15
NO316278B1 (en) 2004-01-05
SE9303194L (en) 1995-03-31
DE69415035T2 (en) 1999-05-06
NO961129L (en) 1996-03-20
SE9303194D0 (en) 1993-09-30
FI111276B (en) 2003-06-30
ES2124430T3 (en) 1999-02-01
WO1995009268A1 (en) 1995-04-06

Similar Documents

Publication Publication Date Title
US4983258A (en) Conversion of pulp and paper mill waste solids to papermaking pulp
US5002633A (en) Conversion of pulp and paper mill waste solids to papermaking pulp
US4780179A (en) Method for producing pulp from printed unselected waste paper
US5137599A (en) Conversion of pulp and paper mill sludge to papermaking pulp
US3833468A (en) System for recovery of fiber from paper mill effluent, including a sieve bend screen
FI112510B (en) Recycling raw materials from the paper industry's waste and recycling them
US3884755A (en) Closed cycle paper sheet production
EP1126076B1 (en) Method and apparatus for cleaning pulp
US5798046A (en) Enhanced removal of hydrophobic contaminants from water clarification systems
US5302245A (en) Integrated wastepaper treatment process
SE9503383L (en) Screw press with separate washing zone for dewatering and washing of fiber suspensions
WO1995009268A1 (en) Method and apparatus for dewatering of a fibre suspension
US5458738A (en) Clarifying suspended solids from liquid process streams
FI88732C (en) Procedure and apparatus for treating backwater
CA2144696A1 (en) Centrifugal deresination of pulp and paper process liquids
US6205675B1 (en) Dehydration machine
GB2064376A (en) Production of fibrous material from waste paper
US7267231B2 (en) Process and device for aerating suspensions
Shammas et al. Completely closed water systems in paper mills
RU2042380C1 (en) Water filter
Nassar et al. Studies on water conservation for Jordan paper and cardboard factories
Woodward Controlling contaminants in the production and use of deinked pulp
WO1996009433A1 (en) Paper pulp washing method
Piyush et al. Impact Of Water Loop Closure In Deinking/Recycling Mills
Young Recovered paper and the US solid waste dilemma

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19960321

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT DE ES FR IT

17Q First examination report despatched

Effective date: 19970204

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: KVAERNER PULPING AS.

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT DE ES FR IT

REF Corresponds to:

Ref document number: 173952

Country of ref document: AT

Date of ref document: 19981215

Kind code of ref document: T

REF Corresponds to:

Ref document number: 69415035

Country of ref document: DE

Date of ref document: 19990114

ET Fr: translation filed
REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2124430

Country of ref document: ES

Kind code of ref document: T3

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20060914

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20060922

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20060926

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20060928

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20060930

Year of fee payment: 13

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070929

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20080401

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20080531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20071001

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20071001

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20071001

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070929