EP0017544B1 - Verfahren zur Herstellung einer Papierpulpe - Google Patents

Verfahren zur Herstellung einer Papierpulpe Download PDF

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Publication number
EP0017544B1
EP0017544B1 EP80400369A EP80400369A EP0017544B1 EP 0017544 B1 EP0017544 B1 EP 0017544B1 EP 80400369 A EP80400369 A EP 80400369A EP 80400369 A EP80400369 A EP 80400369A EP 0017544 B1 EP0017544 B1 EP 0017544B1
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EP
European Patent Office
Prior art keywords
downstream
section
upstream
washing
zone
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
Application number
EP80400369A
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English (en)
French (fr)
Other versions
EP0017544A1 (de
Inventor
Pierre Berger
Christian De Choudens
Gérard Lombardo
Pierre Monzie
Robert Angelier
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.)
Clextral SAS
Original Assignee
Creusot Loire SA
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
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First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=9223444&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0017544(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Creusot Loire SA filed Critical Creusot Loire SA
Priority to AT80400369T priority Critical patent/ATE2799T1/de
Publication of EP0017544A1 publication Critical patent/EP0017544A1/de
Application granted granted Critical
Publication of EP0017544B1 publication Critical patent/EP0017544B1/de
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B9/00—Presses specially adapted for particular purposes
    • B30B9/02—Presses specially adapted for particular purposes for squeezing-out liquid from liquid-containing material, e.g. juice from fruits, oil from oil-containing material
    • B30B9/12—Presses specially adapted for particular purposes for squeezing-out liquid from liquid-containing material, e.g. juice from fruits, oil from oil-containing material using pressing worms or screws co-operating with a permeable casing
    • B30B9/16—Presses specially adapted for particular purposes for squeezing-out liquid from liquid-containing material, e.g. juice from fruits, oil from oil-containing material using pressing worms or screws co-operating with a permeable casing operating with two or more screws or worms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B9/00—Presses specially adapted for particular purposes
    • B30B9/02—Presses specially adapted for particular purposes for squeezing-out liquid from liquid-containing material, e.g. juice from fruits, oil from oil-containing material
    • B30B9/12—Presses specially adapted for particular purposes for squeezing-out liquid from liquid-containing material, e.g. juice from fruits, oil from oil-containing material using pressing worms or screws co-operating with a permeable casing
    • B30B9/121—Screw constructions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B9/00—Presses specially adapted for particular purposes
    • B30B9/02—Presses specially adapted for particular purposes for squeezing-out liquid from liquid-containing material, e.g. juice from fruits, oil from oil-containing material
    • B30B9/26—Permeable casings or strainers
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
    • D21B1/00—Fibrous raw materials or their mechanical treatment
    • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
    • D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
    • D21B1/30—Defibrating by other means
    • 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
    • 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

Definitions

  • the subject of the invention is a process for defibering and washing a cellulosic material for the preparation of paper pulp.
  • paper pulp is generally produced from lignocellulosic material and, more often, from wood.
  • the wood is reduced beforehand into pieces called chips and subjected to a treatment having the object of softening or eliminating the lignin so as to allow thereafter the isolation of the fibers by a mechanical defibration treatment. .
  • thermomechanical pastes Sometimes the softening of the lignin is obtained simply by steaming the shavings with steam, which makes it possible to obtain the so-called thermomechanical pastes.
  • chemical reagents are generally used and the importance of the mechanical treatment necessary to obtain the isolation of the fibers varies in opposite direction to the importance of the chemical treatment carried out.
  • mechanical-chemical or semi-chemical pastes are obtained.
  • defibration processing is carried out in devices rotating at high speed, called disc shredders.
  • Such a machine comprises two parallel screws driven in rotation inside a sheath which envelops them, said screws being provided with fllets whose pitches vary from upstream to downstream and determine several successive treatment zones; each zone comprises a section for conveying the material driven downstream by the rotation of the screws, followed by a braking section; the raw material, generally wood chips, is introduced through an orifice placed upstream of the sleeve and driven by the rotation of the screws to a downstream orifice; each braking section causes progressive compression of the material at the end of the preceding conveying section and forms, by the accumulation of material, a continuous plug which makes it possible to separate one from the other two successive zones.
  • each braking section is made up of threads with inverted pitch normally having the effect of bringing the material upstream. This results in progressive compression of the material at the end of the conveying section to overcome the effect of the braking section.
  • the threads with inverted pitch are provided with windows allowing the passage downstream of a certain quantity of material and therefore controlling the rise in pressure. According to an essential characteristic of the previous patent, by the choice of the width of the windows, a selective advancement of the material is authorized.
  • the material which has not reached a sufficient degree of defibration to allow it to pass through the windows is maintained in the most compressed zone where it undergoes intense kneading, in particular due to the driving in rotation of the screws in the same direction, which, combined with the effect of pressure, makes it possible to obtain defibration without appreciable reduction in the length of the fibers.
  • the material previously impregnated with a reagent is subjected to a washing carried out at the same time as the defibration in at least one of the treatment zones, the washing liquid being injected at the start of the conveyor section for diluting the material, the latter being subjected to a dewatering by filtration of a part of the liquid phase through orifices provided in the sheath upstream of the two braking sections framing the treatment zone.
  • the quantity of washing liquid injected after each spin upstream of the treatment zone next is adjusted according to the conditions of passage of the material in the braking zone located downstream so that the spin produced is limited to a degree of dryness of 50 to 55% allowing the advancement of the material downstream in the next braking section.
  • the installation comprises a sheath 1 consisting of two cylindrical lobes enveloping two screws 2 provided with threads nested one inside the other, as seen in fig. 2.
  • the threads are identical and the screws are rotated in the same direction.
  • the sheath is provided at one end with an orifice 10 for introducing the material which is driven by the effect of the rotation of the screws to an outlet orifice 11 placed at its downstream end.
  • the screws are fitted with threads with various pitches which determine a series of successive zones.
  • the machine comprises four successive zones, I, II, IV followed by a zone V for discharging the treated material.
  • each treatment zone comprises a conveying section A provided with direct pitch threads causing the material to advance downstream for a direction of rotation of the screws, for example clockwise in figs. 3 and 4, and a braking section B preferably provided with inverted pitch threads tending to cause the material to rise upstream and thereby causing braking of the material and therefore compression in the downstream part from section A.
  • the sheath 1 is provided at its upper part and in its vertical plane of symmetry with a plurality of orifices 12, 14 each placed downstream of a braking section , respectively B1, B2, B3.
  • the part 3 of the sheath preceding each braking section B1, B2, B3, B4 is provided with slots 31 making it possible to filter the material entrained by the rotation of the screws inside the sheath.
  • the sheath thus consists of a series of solid parts 4 and filtering parts 3, each filtering part 3 being placed upstream of a braking section B over a length of the order of half of the preceding conveying section. A, the solid part 4 covering the previous braking section and extending over the upstream part of the conveying section.
  • the windows 24 are slots made in the threads 23 with inverted pitch and moving radially from the central shaft 21 to the periphery of the thread.
  • the windows 24 are regularly spaced and the screws are wedged so that, preferably, two windows pass simultaneously in the horizontal plane of symmetry passing through the screw axes.
  • the material consisting of wood chips, is introduced into the interior of the machine through the orifice 10 and driven downstream by the first conveying section A1.
  • zone B1 the material is braked by the effect of the inverted pitch and it therefore accumulates downstream of zone A1. It therefore occurs in the area A1, from upstream to downstream, a compression of the material until a pressure allowing it to compensate for the braking effect to pass to the next area located downstream.
  • the passage of the material downstream takes place essentially through the windows, in particular in the central zone where the openings overlap.
  • the braking section allows selective passage of the material downstream. Indeed, insufficiently defibrated chips cannot pass through the windows because of their width and they therefore remain upstream where they are subjected to intense mixing work causing a combination of compression and shearing effects. and, possibly, a twisting of the fibers, in particular when passing from one screw to another, this work continuing until the sufficiently defibrated parts pass downstream.
  • the chips treated in a machine of this type may have already undergone a lignin softening treatment either by steam or by a chemical reagent.
  • a mechanical defibration treatment the importance of which depends on the chemical treatment previously carried out.
  • This mechanical treatment can advantageously be carried out in a machine of the type described above since it suffices to adapt the mechanical characteristics of the screws, and in particular the pitch of the threads, the width of the windows and the speed of rotation of the screws, in order to achieve passage conditions in the different zones making it possible to obtain a defibration treatment of desired intensity.
  • Such a defibration machine can therefore either be supplied with chips having thus undergone a first delignification treatment, or carry out the impregnation of the reagent in the first treatment zones.
  • the material is entrained in the first conveying section A1 and the braking in section B1 causes progressive compression in the last threads of the conveying section.
  • the sheath is provided with slots 31 whose width is sufficient to allow the liquid phase and the dissolved residues to pass while retaining the solid phase formed by the fibers. It therefore occurs, due to the progressive compression, a filtration of the material upstream of the braking section and in a direction perpendicular to the direction of advancement of the material.
  • the pressure is at its maximum when passing through the braking section B1 which causes a real spin of the material up to a degree of dryness of about 50%.
  • the liquid phase expressed by the compression at the start of the braking section rises upstream in the less compressed areas and is evacuated by the filtering part 3 of the sleeve.
  • the material arriving in the next conveying section A2 has a degree of dryness of the order of 50%.
  • the braking section B1 is provided with windows of adequate width, the material has also undergone a first defibration treatment.
  • the windows provided in the braking section B1 allow passage downstream only of the parts of the material having reached the desired degree of defibration.
  • the insufficiently defibrated parts remain upstream of zone B1, that is to say at the end of zone A1.
  • the compression at this point is even higher and therefore produces a real spin of the material.
  • this is where most of the defibration work takes place. However, this is effected by a combination of compression and shearing effect with, in addition, a certain twist of the fibers.
  • the spin should not be pushed to such an extent that it would compromise the advancement of the material in the braking section. This is why the parameters of the machine will be adjusted, in particular the pitch of the threads and the width of the windows to obtain a degree of wringing allowing passage downstream of a sufficient flow of material. In practice, the conditions for passing through the braking section will be adjusted so that the material is wrung there to a degree of dryness of around 40%.
  • the material admitted upstream of section A2 therefore has two characteristics. On the one hand it was defibrated to a degree determined by the braking section B1 and on the other hand it lost a significant amount, in practice almost half, of the liquor it contained.
  • the material is then diluted with a washing liquid, normally clear water, introduced through the orifice 12 and this dilution is facilitated by the kneading effect produced by the screws.
  • a homogeneous mixture is thus obtained having a degree of dryness of about 20 to 25% which is again compressed as it advances in the conveying section A2.
  • the braking section B2 makes it possible to maintain the material at the end of the section A2 having not reached the desired degree of defibration and on the other hand to wring out this material, the liquid phase rising in the less compressed areas upstream where it is discharged through the slots 31.
  • the material arriving in zone A3 underwent an additional degree of defibration and was again spun to a degree of dryness of around 50%. It is again diluted by a washing liquid introduced through the orifice 13.
  • step by step a series of washing operations is carried out which make it possible to obtain, at the outlet of the machine, a paste which has been at the same time defibrated and washed.
  • the same series of operations is carried out as in the known washing processes, that is to say successive dilutions followed each time by filtration.
  • the dilution and filtration are carried out under very specific conditions: in conventional methods, to obtain a good distribution of the fibers in the washing liquid, the material must generally be diluted in a very large amount liquid. This has the drawback of increasing the water consumption and also the energy consumption necessary to eliminate this water in the next filtration phase.
  • the fact of carrying out the washing at the same time as the defibration greatly increases the efficiency of the washing liquid and therefore makes it possible to reduce its consumption.
  • the washing taking place in successive zones the filtered liquid is recovered in one zone for injection into the preceding zone. This recycling is not useful in the process according to the invention because the filtered liquid, due to the efficiency of the washing, is so concentrated that it cannot itself serve as washing liquid.
  • washing efficiency is also due to the specific characteristics of the machine used and to the very particular process of advancement of the material inside it.
  • the material coming from the upstream braking zone dilutes in the injected liquid. Then part of the liquid is entrained downstream with the material which gradually compresses, the other part filling the relaxed areas. In each thread the alternation of compression and expansion phases promotes the expulsion of the spent liquor and the absorption of clean liquid. When the size of the compressed part increases, the expelled liquor rises upstream along the sheath and is evacuated by the filtering parts 31. Thus, there is a permanent filtration of the spent liquor by the periphery and a renewal cleaner liquid entrained downstream with the material inside the threads.
  • the slots are formed by intervals left between profiles 3 in the form of parallel circumference sectors directed in a direction substantially transverse to the axis of the screws.
  • the profiles have a trapezoidal cross section having the large base facing inwards so as to have a concave cylindrical internal face.
  • the intensity of these operations depends on the conditions of passage of the material in the braking sections which, as indicated, are regulated in particular by the choice of the pitch of the threads and their depth, the number of threads in each zone , the width of the windows and the speed of rotation of the screws.
  • a maximum wringing will be carried out in each braking section limited, however, to the degree of dryness allowing the good advancement of the material from one zone to another.
  • Washing is faster and more efficient. It occurs on a more concentrated dough and makes it possible to reduce the consumption of water for washing and consequently the waste liquor discharges.
  • the effectiveness of washing is usually measured by the ratio of the difference between the quantity of liquor entered with the chips and the quantity of liquor discharged, over the quantity of liquor entered.
  • this ratio is of the order of 60% and may even, under certain conditions, reach 80%.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)
  • Diaphragms For Electromechanical Transducers (AREA)
  • Sanitary Thin Papers (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)
  • Materials For Medical Uses (AREA)

Claims (3)

1. Verfahren zum Zerfasern bzw. Schleifen und Waschen eines zellulosehaltigen Materials zur Herstellung eines Papierfaserstoffes durch Fördern des zu Schnitzeln zerkleinerten und mit einem chemischen Ligninentfernungsmittel getränkten Materials, durch eine Maschine, die wenigstens zwei parallele Schnecken umfasst, welche rotierend im Innern eines Mantelgehäuses angetrieben werden und Schraubengewinde aufweisen, deren Gänge unterschiedlich so ausgebildet sind, dass sie mehrere aufeinanderfolgende Behandlungszonen begrenzen, wobei jede Zone einen Abschnitt, in welchem das Material gefördert und fortschreitend verdichtet wird, und einen Stau-Abschnitt umfasst, der mit Gewinden mit entgegengesetzt gewundenen Schneckengängen versehen ist, die mit Durchlassöffnungen in Strömungsrichtung des Materials abwärts versehen sind, deren Dimensionen so vorgegeben sind, dass sie einen selektiven Vorschub des Materials in Strömungsrichtung abwärts in Abhängigkeit vom Zerfaserungsgrad zulassen, den das Material stromaufwärts von den genannten Öffnungen erreicht hat, dadurch gekennzeichnet, dass das Schleifen und Waschen der Schnitzel in den aufeinanderfolgenden Behandlungszonen der Maschine gleichzeitig erfolgt, deren Mantelgehäuse zu diesem Zweck mit einer abwechselnden Reihe von vollen Abschnitten und Filtrier-Abschnitten versehen ist, die jeweils den stromaufwärts und stromabwärts gelegenen Abschnitt jedes Förderabschnittes bedecken, wobei jeder volle Abschnitt auf dem vorhergehenden Stau-Abschnitt verlängert ist und das Material auf seiner Bahn von in Strömungsrichtung aufwärts bis in Strömungsrichtung abwärts beim Durchlaufen jeder der Behandlungszonen aufeinanderfolgend einer Verdünnung durch Mischen mit einer geeigneten Waschflüssigkeit, die in Strömungsrichtung aufwärts von der Behandlungszone eingebracht wird, darauf im Innern der Schneckengänge einem Wechsel von Phasen einer Expansion und einer zunehmenden Verdichtung und schliesslich einer Trocknung unterworfen wird, die gleichzeitig mit der Zerfaserung in Strömungsrichtung abwärts vom Förderabschnitt und im Stau-Abschnitt vorgenommen wird, wobei die verbrauchte Flüssigkeit durch die Filtrierabschnitte des Mantelgehäuses abgeführt wird.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass die Menge an Waschflüssigkeit, die nach dem Trocknen in Strömungsrichtung aufwärts von der Zone der Zerfaserung unter Waschen eingespritzt wird, in Abhängigkeit von den Bedingungen reguliert wird, unter welchen das Material den in Strömungsrichtung abwärts gelegenen Stau-Abschnitt durchläuft, damit die vorgenommene Trocknung auf einen Trocknungsgrad beschränkt wird, der ausreicht, um den Vorschub des Materials in Strömungsrichtung abwärts in den darauffolgenden Stau-Abschnitt zu gewährleisten.
3. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass in jede Zone der Zerfaserung unter Waschen eine solche Menge Waschflüssigkeit eingespritzt wird, dass das Material in Strömungsrichtung aufwärts von der Zone auf einen Trocknungsgrad von 20% gebracht wird und dass die Durchlaufbedingungen im Stau-Abschnitt so reguliert werden, dass das Material dort auf einen Trocknungsgrad von 55% gebracht wird.
EP80400369A 1979-03-22 1980-03-19 Verfahren zur Herstellung einer Papierpulpe Expired EP0017544B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80400369T ATE2799T1 (de) 1979-03-22 1980-03-19 Verfahren zur herstellung einer papierpulpe.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR7907250 1979-03-22
FR7907250A FR2451963A1 (fr) 1979-03-22 1979-03-22 Procede et installation de preparation et de lavage d'une pate a papier a partir d'une matiere lignocellulosique reduite en morceaux

Publications (2)

Publication Number Publication Date
EP0017544A1 EP0017544A1 (de) 1980-10-15
EP0017544B1 true EP0017544B1 (de) 1983-03-16

Family

ID=9223444

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80400369A Expired EP0017544B1 (de) 1979-03-22 1980-03-19 Verfahren zur Herstellung einer Papierpulpe

Country Status (13)

Country Link
EP (1) EP0017544B1 (de)
JP (1) JPS55132788A (de)
AT (1) ATE2799T1 (de)
AU (1) AU534184B2 (de)
BR (1) BR8001684A (de)
CA (1) CA1131484A (de)
DE (1) DE3062314D1 (de)
DK (1) DK154153C (de)
ES (1) ES489784A1 (de)
FI (1) FI71585C (de)
FR (1) FR2451963A1 (de)
NO (1) NO151974C (de)
NZ (1) NZ193228A (de)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE443383C (sv) * 1981-01-14 1987-11-16 Mo Och Domsjoe Ab Forfarande for tvettning av cellulosamassa
FR2509766A1 (fr) * 1981-07-20 1983-01-21 Creusot Loire Procede de fabrication d'une pate de fivres cellulosique pour utilisation non papetiere
FR2604197B1 (fr) * 1986-09-23 1988-11-18 Atochem Procede de blanchiment de matieres lignocellulosiques.
FR2618811B1 (fr) * 1987-07-31 1990-06-22 Centre Tech Ind Papier Procede de fabrication de pates chimicomecaniques ou chimicothermo-mecaniques blanchies
FR2629844B1 (fr) * 1988-04-06 1991-09-27 Clextral Procede pour la fabrication d'une pate a papier a usage fiduciaire
EP0979895A1 (de) * 1998-08-12 2000-02-16 Instituut Voor Agrotechnologisch Onderzoek (Ato-Dlo) Verfahren und Vorrichtung zum Raffinieren von Fasern
CN102852018A (zh) * 2012-09-11 2013-01-02 江苏金沃机械有限公司 一种双螺杆洗涤机

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2547577A (en) * 1946-07-22 1951-04-03 Detrex Corp Countercurrent extraction apparatus
US3004876A (en) * 1957-03-20 1961-10-17 Int Basic Economy Corp Method for washing fibrous material
FR1480415A (fr) * 1965-04-23 1967-05-12 Werner & Pfleiderer Procédé et équipement pour exprimer l'huile des semences et des fruits oléagineux dans les installations à fonctionnement continu
FR2319737A1 (fr) * 1975-07-31 1977-02-25 Creusot Loire Procede et machine de fabrication de pate a papier

Also Published As

Publication number Publication date
BR8001684A (pt) 1980-11-18
NZ193228A (en) 1984-07-31
FR2451963B1 (de) 1982-05-07
FI71585B (fi) 1986-10-10
JPS55132788A (en) 1980-10-15
NO151974C (no) 1985-07-17
FR2451963A1 (fr) 1980-10-17
ES489784A1 (es) 1980-09-16
NO151974B (no) 1985-04-01
AU534184B2 (en) 1984-01-12
ATE2799T1 (de) 1983-04-15
EP0017544A1 (de) 1980-10-15
DK154153C (da) 1989-05-22
CA1131484A (fr) 1982-09-14
DE3062314D1 (en) 1983-04-21
AU5667980A (en) 1980-09-25
FI71585C (fi) 1987-01-19
FI800887A (fi) 1980-09-23
DK125280A (da) 1980-09-23
DK154153B (da) 1988-10-17
NO800736L (no) 1980-09-23

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