[go: up one dir, main page]

WO2011088888A2 - Caisse de tête basse consommation - Google Patents

Caisse de tête basse consommation Download PDF

Info

Publication number
WO2011088888A2
WO2011088888A2 PCT/EP2010/050572 EP2010050572W WO2011088888A2 WO 2011088888 A2 WO2011088888 A2 WO 2011088888A2 EP 2010050572 W EP2010050572 W EP 2010050572W WO 2011088888 A2 WO2011088888 A2 WO 2011088888A2
Authority
WO
WIPO (PCT)
Prior art keywords
pulp
head box
nozzle
tube bank
flow
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.)
Ceased
Application number
PCT/EP2010/050572
Other languages
English (en)
Other versions
WO2011088888A3 (fr
Inventor
Janne Lappi
Sami Anttilainen
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.)
Valmet Technologies Oy
Original Assignee
Metso Paper Oy
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 Metso Paper Oy filed Critical Metso Paper Oy
Priority to PCT/EP2010/050572 priority Critical patent/WO2011088888A2/fr
Publication of WO2011088888A2 publication Critical patent/WO2011088888A2/fr
Publication of WO2011088888A3 publication Critical patent/WO2011088888A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • 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
    • D21F1/02—Head boxes of Fourdrinier machines
    • D21F1/028—Details of the nozzle section
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
    • D21G9/00—Other accessories for paper-making machines
    • D21G9/0009—Paper-making control systems
    • D21G9/0027—Paper-making control systems controlling the forming section

Definitions

  • the invention relates to a head box for a paper machine or the like, and in particular to a low energy head box having low energy consumption.
  • a head box is the element in a fibrous web machine, like a paper machine, with which the pulp is introduced into the web forming part, i.e. the former of a fibrous web machine.
  • Various types of formers are known; the basic principle is application of a fiber containing pulp with high water content on a wire mesh material through which the water flows out while the fibers are held on the wire mesh material to form the initial fibrous web.
  • a head box usually comprises a nozzle with a slit shaped opening extending over the machine width in machine cross
  • the head box evenly distributes the pulp in machine cross direction over the wire arrangement by suitable adjustment of the flow from the slit shaped nozzle.
  • it is required to provide for a uniform fiber distribution in the pulp itself, which pulp is then evenly distributed on the wire.
  • turbulence is generated in the pulp before it flows out from the nozzle, so as to break up fiber flocks which may occur in the pulp and to generate mixing flows in the pulp.
  • the pressure loss of the turbulence generator is used to level out local pressure differences in the pulp in order to improve the uniformity of the pulp pressure along the nozzle in CD-direction.
  • the turbulence generator has tubes or channels which have a step in their inner diameter forming a sudden and sharp widening of diameter in the channels through which the pulp flows from an inlet manifold of the head box to the nozzle.
  • EP 1 033 436 Al a channel design is shown in which design the diameter of the channel increases in several steps .
  • the inventors have studied the present design of known head boxes as described above. It was found that the turbulence vortices contribute to a reliable breaking up of fiber flocks. However, it was also found that the generation of vortices in the sudden expansion causes a pressure loss, which larger than required for improving the pressure distribution in the pulp. The pressure loss has a
  • a head box is provided with a turbulence generator, the pulp channels of which have a cross-sectional shape which changes gradually. With the gradual change of the channels' internal shape, the pulp channels of which have a cross-sectional shape which changes gradually. With the gradual change of the channels' internal shape, the pulp channels of which have a cross-sectional shape which changes gradually. With the gradual change of the channels' internal shape, the pulp channels of which have a cross-sectional shape which changes gradually. With the gradual change of the channels' internal shape, the pulp channels of which have a cross-sectional shape which changes gradually. With the gradual change of the channels' internal shape, the pulp channels of which have a cross-sectional shape which changes gradually. With the gradual change of the channels' internal shape, the pulp channels of which have a cross-sectional shape which changes gradually. With the gradual change of the channels' internal shape, the pulp channels of which have a cross-sectional shape which changes gradually. With the gradual change of the channels' internal shape, the pulp channels of which have a cross-sectional shape which changes
  • the invention brings a considerable reduction of the pressure loss at the head box as compared to a typical known machine, while maintaining the quality of the
  • the invention thus suggests a head box for a paper machine or the like, which head box comprises a nozzle which is adapted to apply a web-forming, fiber-containing pulp to a wire arrangement, a header to which said pulp is supplied, a tube bank including a plurality of tubes arranged side by side in the cross machine direction and connected to said header and flow control elements arranged in the tube bank for controlling flow passing through the individual tubes of the tube bank.
  • the turbulence generator connects the tube bank to the nozzle, wherein the turbulence generator has pulp channels with the above described internal shape, i.e. having a cross-sectional shape which changes gradually between inlet and outlet of said turbulence generator.
  • the total internal wall surface as defined by the channel axial length and internal circumference length is set to generate a turbulent boundary layer of the pulp flow causing breaking of fiber flocks in the pulp.
  • the cross-sectional shape of the channels of the turbulence generator changes from a circular shape at the tube bank side end to a rectangular shape at the nozzle side end.
  • each channel may be of stepless or smooth and aerodynamic shape.
  • the nozzle is a slice lip nozzle.
  • at least one turbulence vane is arranged at the nozzle end side of each channel, said turbulence vane dividing the pulp flow in the nozzle in a direction crossing the flow direction of the pulp to the wire
  • the slice lip may be locally adjustable towards and away from the nozzle opening for adjusting the base weight profile of the pulp flow in machine cross direction.
  • each flow control element may be adapted to have a maximum control range of 4- 4 % of the main flow.
  • the flow control element has an aerodynamic design with regard to the flow which passes through the control element.
  • the pressure loss of the pulp in the head box is 1 to 25 kPa from the header to the nozzle.
  • Fig. 1 shows sectional view as seen in CD-direction of an embodiment of a head box according to the invention in which a turbulence generator is installed with a slice nozzle;
  • Fig. 2 shows a turbulence generator similar to that of Fig. 1 having several pulp channels in detail.
  • Fig. 1 shows an embodiment of a head box for a paper machine to which the invention is applied.
  • the head box is shown diagrammatically for the sake of clarity.
  • the head box of Fig. 1 is a head box type useable in paper machines which produce paper from pulp which contains large part of recycled paper.
  • the nozzle 1 of the head box has a slit-shaped opening 11 which is defined by a lower lip 14 and an adjustable upper lip or slice lip 12.
  • the position of the slice lip 12 is locally adjustable to adjust the CD-profile of the pulp flow from the opening 11 of the nozzle 1.
  • the nozzle 1 is a multilayer nozzle which has a turbulence vane 13 inside the nozzle downstream of a turbulence generator 2 which will described in detail with reference being made to Fig. 2. It is noted that the turbulence generator shown in Fig. 1 has two pipes for the pulp flow stacked in vertical direction in Fig. 1 while the
  • turbulence generator 2 of Fig. 2 has five pipes stacked in that vertical direction in that drawing figure. It is noted that there are plural of such stacks of pipes arranged next to each other along the width of the nozzle in machine cross direction (CD-direction) and form an array of pipes. In fact a turbulence generator may have several hundred pipes arranged in the array extending over the width of the nozzle in CD-direction.
  • the turbulence vane 13 divides the inside volume or nozzle chamber 15 of the nozzle 1, while the upstream edge of the turbulence vane 13 is connected to or at least arranged at the outlet 22 of the turbulence generator.
  • the pulp flow exiting the turbulence generator 2 is divided (or more precisely: maintained divided) into separate layers of pulp flow.
  • Fig. 1 only a single turbulence vane 13 is shown, but multiple layer nozzles with two or more, even up to seven, vanes are known. Separation into layers may not only be applied if a multi-layered product (web) having layers of different materials shall be made, uniformity of the pulp and the pulp flow may be improved by using the separation technology even if the pulp is the same for all layers.
  • the turbulence vane 13 forms a wall along which the pulp flow has to pass. With the condition that the pulp must be at rest at the wall, a turbulent boundary layer is formed which generates turbulence in the pulp flow
  • the turbulence generator 2 is with its upstream end or inlet 21 connected to a tube bank 4.
  • the tube bank is an row of tubes 41 which are arranged to connect the inlet 21 of the turbulence generator 2 to a header 3 which supplies the pulp to the nozzle 1.
  • the header 3 comprises a tube of large diameter from which the tubes 41 of the tube bank 4 branch off.
  • a flow adjuster 5 with which the pulp flow through the individual tube can be adjusted. It is noted that the flow adjuster 5 is not a valve in the classic sense (providing an on/off- function) but it was found sufficient if the flow adjuster 5 is capable to change the flow within a range of 4- 4%.
  • the adjustment range allows to change the flow in a range of +_ 2,5%.
  • it is possible to select design which penetrate into or disrupt the pulp flow only to a minimum extend (only small constrictions of the flow path are required) so that an overall design is possible which generates only a low pressure loss at the tube bank.
  • designs can be implemented which avoid agglomeration or clogging of fibers due to shapes which do not cause severe deviations of the pulp flow in the tube bank .
  • Fig. 2 shows a turbulence generator 2 which is similarly structured as that of Fig. 1 in more detail.
  • Fig. 2 one stack of pipes forming the pulp channels as defined in the claims is shown, which stack is only a single layer or row of vertically stacked pipes. It is noted that a plurality of such stacks is arranged side by side in a direction perpendicular to drawing plane of Fig. 2 i.e. in the CD- direction (cross machine direction) of the paper machine to form an array of several tenths (or hundereds) of pipes X five pipes.
  • the individual pipes 231 to 235 are stacked one on top of the other and they are held in position by means of a holder 61, 62 having suitable holes for receiving the pipes.
  • Each pipe 231 to 235 has an inlet 211 to 215 which is of substantially circular cross-sectional shape.
  • the circular shape of the cross-section of the pipes changes to a rectangular or square shape, so that the individual pipe outlets 221 to 225 each have a rectangular or square cross-section. It is noted that there are no sharp edges or bends involved in this change of shape.
  • a slice or nozzle chamber may be is arranged downstream the turbulence generator of Fig. 2 as well (not shown) .
  • turbulence vanes here four vanes, each of them being arranged between two outlet openings
  • each individual pipe 231 to 235 has no step or steps when changing its cross- sectional shape over its length.
  • the central pipe 233 is straight, while the adjacent pipes 232 and 234 are slightly bent towards the outlet 223 of the central pipe 233.
  • similarly to outer pipes 231 and 235 are bent slightly more towards the central pipe 233 to bring the outlets 221 and 225 closer to the outlet 223 of the central pipe 233. It is noted that these bends are not sharp, so as to not generate edges inside the pipes.
  • the diameters of the pipes are set such that there is a trade-off between the pressure loss in the so formed pulp channels on the one hand, and, on the other hand,
  • the pressure loss of the pulp in the head box is 1 to 25 kPa from the header to the nozzle.
  • the head box of the invention In a comparison between the head box of the invention and a typical head box which is nowadays commonly used in a typical paper machine it was found that there is significant energy saving potential of about 25% which may make up an annual energy saving of about 1000000 kWh.

Landscapes

  • Paper (AREA)

Abstract

La présente invention concerne une caisse de tête pour une machine à papier ou similaire, dans laquelle une buse est conçue pour appliquer une pâte contenant des fibres destinée à former une feuille sur un agencement de toile. La caisse de tête comprend un collecteur auquel est fournie ladite pâte, une rangée de tuyaux comprenant une pluralité de tuyaux disposés côte à côte dans le sens travers et raccordés au collecteur. Des éléments de régulation du débit sont disposés dans la rangée de tuyaux pour réguler le débit passant à travers les différents tuyaux de la rangée de tuyaux. En aval de la rangée de tuyaux se trouve un générateur de turbulences qui raccorde le tuyau à la buse. Le générateur de turbulences présente des conduites de pâte dont la forme transversale change progressivement entre l'entrée et la sortie dudit générateur de turbulences. De préférence, la surface de paroi interne totale telle que définie par la longueur axiale des conduites et la longueur circonférentielle interne est définie pour générer une couche limite turbulente du débit de pâte entraînant la rupture des flocons de fibre dans la pâte de sorte que, par exemple, le passage de chaque conduite doit être de forme progressive et aérodynamique.
PCT/EP2010/050572 2010-01-19 2010-01-19 Caisse de tête basse consommation Ceased WO2011088888A2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/EP2010/050572 WO2011088888A2 (fr) 2010-01-19 2010-01-19 Caisse de tête basse consommation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2010/050572 WO2011088888A2 (fr) 2010-01-19 2010-01-19 Caisse de tête basse consommation

Publications (2)

Publication Number Publication Date
WO2011088888A2 true WO2011088888A2 (fr) 2011-07-28
WO2011088888A3 WO2011088888A3 (fr) 2011-09-29

Family

ID=44217492

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2010/050572 Ceased WO2011088888A2 (fr) 2010-01-19 2010-01-19 Caisse de tête basse consommation

Country Status (1)

Country Link
WO (1) WO2011088888A2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103734898A (zh) * 2013-12-19 2014-04-23 云南中烟昆船瑞升科技有限公司 一种再造烟叶智能成型器

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1033436A2 (fr) 1999-03-02 2000-09-06 Voith Sulzer Papiertechnik Patent GmbH Procédé et dispositif pour le dosage d'un milieu fluide dans l'écoulement d'une suspension dans une caisse de tête
WO2001096658A1 (fr) 2000-06-13 2001-12-20 Metso Paper, Inc. Procede de fluidification de l'ecoulement de pate a papier dans la caisse d'arrivee d'une machine a papier ou similaire et equipement de commande utilise dans cette operation de fluidification

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10331040A1 (de) * 2003-07-09 2005-01-27 Voith Paper Patent Gmbh Stoffauflauf
FI20065196A7 (fi) * 2006-03-27 2007-09-28 Metso Paper Inc Muodostusosa

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1033436A2 (fr) 1999-03-02 2000-09-06 Voith Sulzer Papiertechnik Patent GmbH Procédé et dispositif pour le dosage d'un milieu fluide dans l'écoulement d'une suspension dans une caisse de tête
WO2001096658A1 (fr) 2000-06-13 2001-12-20 Metso Paper, Inc. Procede de fluidification de l'ecoulement de pate a papier dans la caisse d'arrivee d'une machine a papier ou similaire et equipement de commande utilise dans cette operation de fluidification

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103734898A (zh) * 2013-12-19 2014-04-23 云南中烟昆船瑞升科技有限公司 一种再造烟叶智能成型器

Also Published As

Publication number Publication date
WO2011088888A3 (fr) 2011-09-29

Similar Documents

Publication Publication Date Title
US8221590B2 (en) Headbox for a machine for producing a fibrous web
US8303774B2 (en) Headbox for a machine for producing a fibrous web
US8236137B2 (en) Headbox for a machine for producing a fibrous web
US20110083603A1 (en) Curtain coater
JP4571718B2 (ja) 抄紙機のフローボックスに補助的な材料を調量するための装置及び方法
US4070238A (en) Headbox for delivering a jet of well dispersed fibrous stock
US20120168105A1 (en) Headbox for a machine for producing a fibrous web
CA2641256A1 (fr) Caisse de tete et systeme d'alimentation en pate de machine a papier
CN102822416A (zh) 用于制造纤维幅的机器的流浆箱
US7429307B2 (en) Method of forming a fibrous web
WO2010145871A3 (fr) Caisse de tête pour une machine servant à fabriquer une bande de matière fibreuse
US6099692A (en) Headbox turbulence generator
WO2011088888A2 (fr) Caisse de tête basse consommation
US8075736B2 (en) Deflection compensation roll
US7955474B2 (en) Tube bank apparatus for distributing stock
CN102947504B (zh) 用于制造纤维料幅的机器的流浆箱
US8075737B2 (en) Headbox apparatus for a papermaking machine
FI101726B (fi) Säätövirtausjärjestelmä (menetelmä ja -laite) paperikoneen perälaatiko ssa
US9422665B2 (en) Headbox apparatus
CN102822417B (zh) 流浆箱和带有流浆箱的成页单元
US7897016B2 (en) Headbox apparatus for a papermaking machine
FI125186B (fi) Menetelmä ja laitteisto kuiturainakoneella valmistettavan kuiturainan z-suuntaisen anisotropian hallitsemiseksi
US3652391A (en) Box-like blending chamber with barrier elements to produce uniform flow of papermaking stock
US7794570B2 (en) Headbox apparatus for a papermaking machine
EP1195463B1 (fr) Caisse de tête pour machine à papier

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10702075

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase in:

Ref country code: DE

122 Ep: pct app. not ent. europ. phase

Ref document number: 10702075

Country of ref document: EP

Kind code of ref document: A2