EP1543192A1 - Procede et agencement pour remplacer un liquide situe a l'interieur de fibres par un liquide de remplacement - Google Patents

Procede et agencement pour remplacer un liquide situe a l'interieur de fibres par un liquide de remplacement

Info

Publication number
EP1543192A1
EP1543192A1 EP03795542A EP03795542A EP1543192A1 EP 1543192 A1 EP1543192 A1 EP 1543192A1 EP 03795542 A EP03795542 A EP 03795542A EP 03795542 A EP03795542 A EP 03795542A EP 1543192 A1 EP1543192 A1 EP 1543192A1
Authority
EP
European Patent Office
Prior art keywords
fibers
liquid
replacement liquid
fiber
compression
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Withdrawn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
EP03795542A
Other languages
German (de)
English (en)
Inventor
Asa Samuelsson
Birger SJÖGREN
Hannes Vomhoff
Lars SJÖSTRÖM
Marco Lucisano
Mikael Lindström
Tommy Iversen
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.)
STFI Skogsindustrins Tekniska Forskningsinstitut AB
Original Assignee
STFI Skogsindustrins Tekniska Forskningsinstitut AB
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 STFI Skogsindustrins Tekniska Forskningsinstitut AB filed Critical STFI Skogsindustrins Tekniska Forskningsinstitut AB
Publication of EP1543192A1 publication Critical patent/EP1543192A1/fr
Withdrawn legal-status Critical Current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
    • 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
    • D21C9/02—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents
    • D21C9/06—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents in filters ; Washing of concentrated pulp, e.g. pulp mats, on filtering surfaces
    • 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
    • D21C9/001—Modification of pulp properties
    • D21C9/007—Modification of pulp properties by mechanical or physical means

Definitions

  • the present invention is generally directed to a process and an arrangement for replacing intra-fiber liquid in fibers with a replacement liquid.
  • cooked or digested materials such as wood pulp fibers or textile fibers such as cotton fibers and other fibers with pores in their fiber walls, are containing various chemicals or substances that are less desirable or eligible. To get rid of or at least lessen their contents various methods of washing fibers have been used.
  • the original method used for fiber washing is dilution - extraction. It consists of diluting a fiber slurry with a weaker liquid and subsequently thicken it and raising the consistency. Diffusion has also been used for washing fibers where wash liquid is mixed with the fibers and at some time later, up to a few hours, is displaced.
  • Vacuum washers have also been used where the liquid content of the fibers are extracted by an applied vacuum while being subsequently replaced by a wash liquid.
  • Another method is by using pressure washers.
  • the principle is to apply mechanical pressure on the fiber cake using screws, rolls or a horizontal belt or the like. The thickness of the fiber cake is gradually reduced and the liquid is expressed.
  • fibers Due to their special nature, fibers also contain liquid inside the fiber wall and also in the lumen. This liquid is henceforward called intra-fiber liquid. So far, the methods used to eliminate the liquid in fiber cakes have only aimed to substitute the liquid contained in pores between the fibers, henceforward called inter-fiber liquid, and not the substantial amount of intra-fiber liquid. To get rid of a substantial amount of the intra-fiber liquid very high pressures are needed. A desired c onsistency is well over 40 %. This level is usually depending on the type of fiber used. In the state of art sufficiently high pressures have for different reasons not been used. High energy consumption and excessive stress in the machinery u sed are probable reasons.
  • the replacement liquid is cleaner liquid.
  • the replacement liquid contains chemical treating agent. It is in another preferred embodiment of the invention suggested that the replacement liquid is acid or basic for fast acid or base treatment of the pulp fibers.
  • the replacement liquid contains bleaching chemical.
  • the replacement liquid contains delignifying agent.
  • the replacement liquid contains process catalyst.
  • the replacement liquid contains chelating agent. It is in another preferred embodiment of the invention suggested that the replacement liquid contains fluorescent tracer.
  • the replacement liquid contains metal ions. It is in another preferred embodiment of the invention suggested that the replacement liquid contains cationic or anionic polymer.
  • the replacement liquid contains dying substance to dye the fibers.
  • the replacement liquid contains inorganic substance.
  • the object is also achieved according to the present invention by an arrangement comprising a device for compressing the fiber cake to such a degree that a substantial quantity of intra-fiber liquid is expressed to the space between the fibers and partially out of the fiber cake, a first device for forcibly supplying the replacement liquid to the fibers during the compression and a second device for supplying the replacement liquid immediately after the device for compression arranged in an expansion area where the fibers are allowed to expand after the compression while absorbing the replacement liquid.
  • the device for compressing the fibers comprises a rotating compression roll and a press arranged opposite the compression roll with a press nip in which the fibers are fed and the device for forcibly supplying the replacement liquid to the fibers during the compression is a compressible fabric with liquid permeability only in the thickness direction arranged as a moving closed loop in at least partly contact with the compression roll where at least a part of the closed loop in the press nip is in contact with the compressed fibers.
  • the device for compressing the fibers comprises a rotating compression roll and a press arranged opposite the compression roll with a press nip in which the fibers are fed and the device for forcibly supplying the replacement liquid to the fibers during the compression comprises radial holes in the compression roll and a pressurized replacement liquid container arranged in the compression area to supply pressurized replacement liquid through the holes from the inside of the compression roll into the fibers in the compression area.
  • the second device supplying the replacement liquid is a trough which has a lower opening at an outlet from the device for compressing the fibers. It is in another preferred embodiment of the invention suggested a system where more than one arrangement are arranged in series.
  • liquid in this application should be interpreted rather broad and not only mean liquids as such. Thus it is our meaning that it also should include suspensions, dispersions and the like.
  • Fig. 1 is a schematic side view of an arrangement according to the present invention
  • Fig. 2 is a schematic side view of a second embodiment of an arrangement according to the present invention.
  • Fig. 3 is a schematic side view of a third embodiment of an arrangement according to the present invention.
  • Fig. 4 is a schematic side view of a fourth embodiment of an arrangement according to the present invention.
  • Fig. 5 is a view of part of the embodiment showed in figure 4;
  • Fig. 6 is a graph showing the intra-fiber and inter-fiber liquid content of fibers as a function of the compression pressure;
  • Fig. 7 is a schematic flow chart of the process of the present invention.
  • FIG. 7 is illustrating a process according to the invention having the following steps; compressing a fiber cake to such a degree that a substantial quantity of the contaminated intra-fiber liquid is expressed to the space between the fibers and partially out of the fiber cake.
  • a replacement liquid is forcibly supplied to the fiber cake during the compression and displacing the intra-fiber liquid from the space between the fibers.
  • the whole process means that an exchange or replacement has taken place where the replacement liquid has replaced the contaminated liquid not altogether but in such a degree that the content of the contaminant in the treated fibers is diluted in a high degree.
  • a device generally comprises a belt or wire 1 on which a fiber cake 12 is transported along a predestinated route by motor-driven transport rolls 2 and 3 arranged in parallel with and on each side of a compression roll 4.
  • the compression roll 4 is directly or indirectly driven by a motor.
  • the compression of the fibers takes place between the rotating compression roll 4, which is transversally arranged on the side of the wire 1 where the fibers are placed, and a shoe or roll press 5 arranged on the opposite side of the wire 1 from the compression roll 4 in such a manner that a press nip results where the fibers are compressed and deliquefied.
  • the compression is among other things depending upon how close the compression roll 4 and the press 5 are to each other, i.e.
  • a compressible fabric 6 is arranged as a closed loop on the envelope surface of the compression roll 4 to be rotated together with the roll 4 between it and the fiber cake.
  • the fabric 6 is permeable to liquid by way of pores arranged in its thickness direction resulting in a permeability in the thickness direction exclusively.
  • the trough 7 has a lower opening in its bottom through which the compressible fabric 6 is transported and thus being compressed expands and sucks up replacement liquid.
  • This "liquid filled" area of the compressible fabric is then by way of the rotation of the compression roll 4 transported to the beginning of the roll wrap area and further on to the compression area again where the replacement liquid is pressed out of the pores and into the fiber cake.
  • the replacement liquid is thus displacing the contaminated liquid and at the same time starting to be absorbed by the fiber wall pores and the lumens by way of convection.
  • the wire 1 with the compressed fibers is transported through the lower opening 13 of the trough 7 just after the compression roll 4 and being relieved from the compression pressure, the fibers expand while sucking up even more of the replacement liquid from the trough 7.
  • This expansion phase reduces the concentration of the contamination in the fiber cake both between the fibers and in the fiber wall and lumen as the replacement liquid eventually finds its w ay there through diffusion.
  • the expansion of the fiber cake usually takes more than 0.5 seconds. To maximally make use of this time it is preferred if the time the fiber cake is in contact with the replacement liquid in the trough is more than 0.5 seconds.
  • a second step or even more steps, of this compression- expansion process could be used in which two or more arrangements according to the invention are arranged in series. This would make it possible to further process the fibers supplying different kinds of replacement liquids for different purposes such as washing, bleaching and so on in a system. Suggestions as to what kinds of replacement liquids are possible to use are made later in this description.
  • Figures 2 and 3 disclose embodiments of the present invention similar to the embodiment showed in figure 1.
  • the trough 7 is substituted by a replacement liquid reservoir 14 defined by a part of the interior of the closed loop of the compressible fabric 6 and a part the envelope surface of the compression roll 4.
  • This reservoir 14 is in figure 2 arranged just before the closed loop goes into contact with the compression roll 4 and in figure 3 after the closed loop leaves contact with the compression roll 4.
  • the replacement liquid is added to the inside of the closed loop.
  • This arrangement has the advantage that the pores of the compressible fabric 6 are filled from the inside, preventing the occurrence of air in the pores which would hinder the flow out of the pores in the compression phase.
  • a further improvement in these embodiments is a second reservoir 16 defined by a part of the exterior of the closed loop of the compressible fabric 6 and a flow restrictor 15 which forms a narrow slit with the fabric in the bottommost part of the reservoir 14.
  • the flow restrictor collects the liquid that flows through the compressible fabric 6 and avoids unnecessary flow of replacement liquid.
  • This second reservoir 1 6 is in the embodiment of figure 2 arranged just before the closed loop goes into contact with the compression roll 4 and in figure 3 after the closed loop leaves contact with the compression roll 4. Even though it is not shown in the figures it is of course possible to include a trough 7 in these embodiments just like the trough 7 in the embodiment shown in figure 1.
  • the compression roll 4 is substituted for a compression roll 4a which is formed as a roll shell with radial holes 8 in the same manner as in the compressible fabric 6 in the first embodiment.
  • the compressible fabric is in this way superfluous.
  • a pressurized replacement liquid container 9 supplies the liquid to the compressed fiber cake in the compression area in the press nip while the replacement liquid trough 7 is still present to supply liquid during the expansion phase.
  • the press 5a can in this case also be of a shoe press or roll press type.
  • Indicated in figures 2 and 3 are a shoe press comprising an impermeable shoe press belt 10. The belt 10 is moving through the container 9 at the same speed as the compression roll 4a.
  • the belt 10 is on the side not in contact with the wire 1 influenced by a support pressure and thus acting as a counter support for the forces applied by the compression roll 4a while also balancing pressure from the pressurized replacement liquid container 9 on the compression roll 4a.
  • This support pressure is in this embodiment supplied by a pressurized liquid, preferably hydraulic oil, in a chamber 11 closed by the belt 10.
  • the liquid in the replacement liquid trough 7 and supplied by the first device for forcibly supplying the replacement liquid is usually cleaner liquid but can in yet another alternative embodiment of the invention contain chemical treating agents.
  • Such treating agents can be acid or basic liquid for the acid or base treatment of the fibers, inorganic substances, bleaching chemicals, process catalysts, chelating agents, tracer substances such as fluorescent substances, metal ions for substituting e.g. Ca-ions in the fibers for Na- or Mg- ions, and cationic polymers to prevent release of anionic substances from the fibers or anionic polymers to get a bulking effect on the fibers (including native polymers).
  • Figure 6 discloses a graph showing the intra-fiber liquid and inter-fiber liquid content of fibers as a function of the compression pressure.
  • the graph is taken from Laivins, G. V., Scallan, A. M. (1993): "Removal of water from pulps by pressing- Part 1: Inter- and Intra-wall water", Tappi Engineering Conference, 741-747 and clearly shows that the instant effect on the content when a pressure is applied mostly influence the inter-fiber content.
  • the removed intra-fiber liquid is finally becoming dominant over the inter-fiber liquid. This usually corresponds to a dryness (consistency) of between 30 and 40%.
  • the real impact of the compression on the liquid content in the fiber wall is thus only obvious at higher pressures or dryness percentages.
  • Fibers with contaminants are fed onto the belt or wire 1 as a fiber cake.
  • the wire 1 with the fiber cake is transported by the transport rolls 2 and 3 preferably as a continuous conveyor.
  • the fiber cake is thus pre-deliquefied somewhat by the roll wrap caused by the endless wire 1 and fiber cake being wrapped around a sector of the compression roll 4.
  • the fiber cake is thereafter transported into the main compression area of the press nip between the compression roll 4 and the press 5. There liquid is pressed out of the fibers and the fiber wall pores and fiber lumens and partially out of the fiber cake.
  • the fabric 6 is compressed and replacement liquid in its pores is pressed out and to a large extent is pressed through the fiber cake.
  • the press nip is such that the compression corresponds to a consistency of well over 40%, preferably over 50% at which a substantial amount of the intra-fiber liquid is removed.
  • the fiber cake As soon as the fiber cake has passed the press nip it is transported through the opening in the bottom of the replacement liquid trough 7. Since the pressure on the fiber cake 12 is released, the fibers expand and absorb additional replacement liquid.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Treatment Of Fiber Materials (AREA)
  • Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)

Abstract

L'invention concerne un procédé pour remplacer un liquide situé à l'intérieur de fibres par un liquide de remplacement, ledit procédé comprenant les étapes suivantes : compression du gâteau de fibres à un degré tel qu'une quantité substantielle de liquide contenu dans les fibres soit exprimée vers l'espace entre les fibres et partiellement à l'extérieur du gâteau de fibre ; acheminement forcé du liquide de remplacement au gâteau de fibres pendant la compression et par conséquent remplacement du liquide contenu entre les fibres à partir de l'espace entre les fibres et dilatation des fibres pendant l'acheminement du liquide de remplacement supplémentaire qui est ainsi absorbé en outre par les fibres dilatées. L'invention concerne également un agencement pour remplacer un liquide situé à l'intérieur de fibres par un liquide de remplacement, ledit agencement comprenant un dispositif (1, 4, 5) servant à comprimer le gâteau de fibre à un degré tel qu'une quantité substantielle de liquide contenu dans les fibres soit exprimée vers l'espace entre les fibres et partiellement à l'extérieur du gâteau de fibre, un premier dispositif (6, 8, 9) servant à acheminer, de manière forcée, le liquide de remplacement aux fibres pendant la compression, et un deuxième dispositif (7) servant à acheminer du liquide de remplacement supplémentaire immédiatement après le dispositif de compression disposé dans une zone de dilatation où les fibres peuvent se dilater après la compression tout en absorbant le liquide de remplacement. L'objectif de l'invention est d'éliminer ou de réduire de manière importante le matériau contaminant non seulement dans les zones situées entre les fibres dans un gâteau de fibres mais aussi dans les pores des parois de fibres et dans les canaux intérieurs des fibres pour remplacer ce liquide par un liquide de remplacement.
EP03795542A 2002-09-16 2003-09-16 Procede et agencement pour remplacer un liquide situe a l'interieur de fibres par un liquide de remplacement Withdrawn EP1543192A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
SE0202733 2002-09-16
SE0202733A SE0202733D0 (sv) 2002-09-16 2002-09-16 Process och arrangemang för att ersätta vätska i fibrer med en ersättningsvätska
PCT/SE2003/001443 WO2004025019A1 (fr) 2002-09-16 2003-09-16 Procede et agencement pour remplacer un liquide situe a l'interieur de fibres par un liquide de remplacement

Publications (1)

Publication Number Publication Date
EP1543192A1 true EP1543192A1 (fr) 2005-06-22

Family

ID=20288995

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03795542A Withdrawn EP1543192A1 (fr) 2002-09-16 2003-09-16 Procede et agencement pour remplacer un liquide situe a l'interieur de fibres par un liquide de remplacement

Country Status (6)

Country Link
US (1) US20060124259A1 (fr)
EP (1) EP1543192A1 (fr)
AU (1) AU2003261052A1 (fr)
CA (1) CA2499005A1 (fr)
SE (1) SE0202733D0 (fr)
WO (1) WO2004025019A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005050658A1 (de) * 2005-10-20 2007-04-26 Basf Ag Verfahren zur Verminderung der Absorption von Wasser und Wasserdampf und zur Erhöhung der Dimensionsstabilität von Papier und Papierprodukten und Verwendung von beschichteten Papierprodukten
CN107489053B (zh) * 2017-09-26 2019-12-24 深圳德为纤维环保科技有限公司 一种改进的洗浆机或分丝机
CN110139958A (zh) * 2017-09-26 2019-08-16 深圳德为纤维环保科技有限公司 用于对纸浆洗涤的设备

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Publication number Priority date Publication date Assignee Title
US2355091A (en) * 1939-03-16 1944-08-08 Brown Paper Mill Company Inc Apparatus for the treatment and removal of chemicals from cooked or digested fiber pulp
SE318183B (fr) * 1968-05-24 1969-12-01 Karlstad Mekaniska Ab
US4661205A (en) * 1981-08-28 1987-04-28 Scott Paper Company Method of bleaching lignocellulosic material with peroxide catalyzed with a salt of a metal
NO159494C (no) * 1986-10-23 1989-01-04 Kvaerner Eureka As Fremgangsmaate ved bleking av cellulosemasse eller fraksjon derav, anlegg til bruk ved gjennomfoeringen av fremgangsmaaten.
US5482594A (en) * 1991-08-21 1996-01-09 Salminen; Reijo Liquid removal apparatus and method for wood pulp
US5785810A (en) * 1991-08-21 1998-07-28 Salminen; Reijo K. Wood pulp processing apparatus and method
US5722264A (en) * 1995-08-07 1998-03-03 Beloit Technologies, Inc. Single roll displacement wash press
NZ331438A (en) * 1997-09-16 2000-01-28 Ciba Sc Holding Ag A method of increasing the whiteness of paper by using a formulation containing a swellale layered silicate and an optical brightener 4,4-bis-(triazinylamino)-stilbene-2,2-disulphonic acid

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2004025019A1 *

Also Published As

Publication number Publication date
CA2499005A1 (fr) 2004-03-25
WO2004025019A1 (fr) 2004-03-25
SE0202733D0 (sv) 2002-09-16
US20060124259A1 (en) 2006-06-15
AU2003261052A1 (en) 2004-04-30

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