[go: up one dir, main page]

EP3436634A1 - Agencement d'alimentation de classeur - Google Patents

Agencement d'alimentation de classeur

Info

Publication number
EP3436634A1
EP3436634A1 EP17775982.6A EP17775982A EP3436634A1 EP 3436634 A1 EP3436634 A1 EP 3436634A1 EP 17775982 A EP17775982 A EP 17775982A EP 3436634 A1 EP3436634 A1 EP 3436634A1
Authority
EP
European Patent Office
Prior art keywords
pulp
discharge tank
outlet
tank
screen feed
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Withdrawn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
EP17775982.6A
Other languages
German (de)
English (en)
Other versions
EP3436634A4 (fr
Inventor
Andreas Engelfeldt
Magnus Hägglund
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
Valmet AB
Original Assignee
Valmet Oy
Valmet 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 Valmet Oy, Valmet AB filed Critical Valmet Oy
Publication of EP3436634A1 publication Critical patent/EP3436634A1/fr
Publication of EP3436634A4 publication Critical patent/EP3436634A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21D—TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
    • D21D5/00—Purification of the pulp suspension by mechanical means; Apparatus therefor
    • D21D5/02—Straining or screening the pulp
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21D—TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
    • D21D5/00—Purification of the pulp suspension by mechanical means; Apparatus therefor
    • D21D5/28—Tanks for storing or agitating pulp
    • 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
    • D21C7/00—Digesters
    • D21C7/06—Feeding devices
    • 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
    • D21C7/00—Digesters
    • D21C7/08—Discharge devices

Definitions

  • the present invention relates generally to a system for feeding cellulose pulp to a screening arrangement and comprises a screening arrangement, a discharge tank connected to a discharge tank pump, a dilution tank, and a screen feed pump, the outlet of which is connected to the screening arrangement, wherein an outlet of the discharge tank pump and an outlet of the dilution tank are connected to the screen feed pump; and more particularly to a system for feeding cellulose pulp to a screening arrangement, wherein there is essentially no dilution of the pulp in the discharge tank and the pulp coming from the discharge tank has a mass concentration of about 8-15 %.
  • a process system for the production of cellulose pulp comprises typically a discharge tank, which during operation is being filled with cellulose pulp coming from one or more digesters.
  • a discharge tank can be filled with pulp which has been processed in other ways, e.g. an oxygen delignification process, wherein the pulp has been exposed to an oxygen stage.
  • the outlet of the discharge tank is connected to a discharge tank pump, which feeds the cellulose pulp from the discharge tank to a screening arrangement, in which the pulp is screened.
  • Most screening arrangements for the screening of cellulose pulp requires a rather low mass concentration of the pulp, and before entering the screening arrangement, the pulp is therefore diluted with liquid from a dilution tank, from an original mass concentration of about 8-15 % when coming from the digester, i.e.
  • the discharge tank which is also referred to as the blow tank or the storage tank or the storage tower, is a large and high container, and the dilution takes place in a bottom portion thereof.
  • agitators are typically arranged in the bottom portion of the discharge tank. A drawback with this arrangement is that the energy consumption of the agitators in the bottom portion of the discharge tank is high.
  • An object of the present invention is therefore to provide an improved screen feed arrangement, which is more energy efficient.
  • a further object is to provide a screen feed arrangement which is easier to regulate.
  • a still further object is to provide a screen feed arrangement by which it is easier to dimension and match the capacity of a screen feed pump to the requirements of a screening arrangement.
  • a system for producing pulp typically cellulose pulp, comprises a discharge tank, which is arranged downstream one or more digesters and is used to collect pulp from the digester and operates as a buffer tank before the pulp is fed to, e.g., a screening arrangement.
  • the pulp does not need to come immediately from a digester, instead the pulp can have been further processed, e.g. in an oxygen delignification process, such that the pulp, which is fed into a discharge tank, comes from, e.g., an oxygen stage.
  • the pulp coming from the digester (or from another process step) has typically a mass concentration of about 8-15 %, whereas the screening arrangement requires a low mass concentration of about 3-5 %.
  • a discharge tank pump which is adapted for the pumping of pulp having a mass concentration of about 3-5 %, is arranged at an outlet disposed in the bottom portion of the discharge tank.
  • agitators provided in this bottom portion of the discharge tank, to agitate the pulp and thereby create an even and stable mass concentration.
  • there is no dilution of the pulp in the discharge tank and preferably no agitators are provided in the discharge tank - although scrapers can optionally be arranged in a bottom portion of the discharge tank.
  • the pulp having a mass concentration of about 8-15 % is pumped from the discharge tank by a discharge tank pump, which is a medium-consistency pump capable of pumping a pulp mass concentration of about 8-15 %.
  • the discharge tank and in particular the outlet of the discharge tank are configured for discharge of pulp having a mass concentration from about 8 % to about 15 %.
  • the inlet side of the screen feed pump is also in connection with an outlet of a dilution tank, and in one embodiment of the invention, a three-way pipe is arranged between a dilution tank and a screen feed arrangement, such that the pulp from the discharge tank is introduced into the flow of dilution liquid from the dilution tank to the screen feed pump.
  • the outlet of the screen feed pump is connected to a screening arrangement and feeds diluted pulp, which has a mass concentration of about 3- 5 % (or even lower), to this screening arrangement.
  • the dilution tank is a reject tank, which is used to collect rejects coming from one or several screens which are parts of a screening arrangement. (In known systems used today, such a reject tank is, via a reject tank pump, instead connected to the discharge tank, to dilute the pulp contained therein.)
  • Fig. 1 is schematic illustration of a screen feed arrangement according to the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
  • Fig. 1 illustrates schematically a screen feed arrangement or system 1, which is part of a pulping process for the production of pulp, typically cellulose pulp.
  • the screen feed arrangement 1 can be used on many types of pulp; for example, mechanical pulp (e.g. groundwood pulp, stone groundwood pulp, thermomechanical pulp), chemi-mechanical pulp (e.g. chemi-thermomechanical pulp) and semi-chemical pulp (e.g. neutral sulphite semi-chemical pulp).
  • the pulp can also be made from wood raw-materials or one-year plants.
  • the screen feed arrangement 1 comprises a discharge tank 2, which has an inlet 3 and an outlet 4.
  • the inlet 3 of the discharge tank 2 is via a pipe 17 connected to a digester (not shown in the figure), which produces pulp having a so-called medium consistency, which implies a mass concentration in the interval of about 8 % to 15 %, or about 8 % to 13 %.
  • pulp which is fed into the discharge tank, can also come from another type of intermediate process step, such as from an oxygen step.
  • Pulp enters the discharge tank 2 via the inlet 3 arranged in a top portion of the discharge tank 2 and leaves the discharge tank 2 via the outlet 4, which is arranged in a bottom portion of the discharge tank 2.
  • the discharge tank 2 has a tapered, i.e.
  • conical, bottom portion 5, and the outlet 4 is located at the bottom part of the conical bottom portion 5.
  • To provide a tapered bottom portion of a discharge tank, with an outlet arranged in the very bottom part thereof, is therefore considered to be a preferred embodiment of the present invention.
  • Other shapes of a bottom portion of a discharge tank as well as other positions for an outlet therefrom are, however, within the scope of the present invention.
  • the discharge tank pump 7 operates at so-called medium consistency, i.e. discharge tank pump 7 is a pump capable of pumping medium-consistency pulp having a medium mass concentration of about 8-15 %.
  • discharge tank pump 7 is a pump capable of pumping medium-consistency pulp having a medium mass concentration of about 8-15 %.
  • the pumping of a relatively smaller volume of medium-consistency pulp requires less energy than the pumping of a relatively larger volume of low-consistency pulp, e.g. pulp with a mass concentration of about 3-5 %.
  • the outlet 1 1 of the dilution tank 9 is, via a pipe 20, connected to an inlet 12 of a screen feed pump 13.
  • the dilution tank 9 is directly connected to the inlet 12 of the screen feed pump 13, i.e. that there are no other components or devices arranged in the pipe 20, or at least no active devices, such as a separate pump, arranged in the pipe 20.
  • the screen feed pump 13 has an outlet 14, which, via a pipe 21, is connected to a screening arrangement 15.
  • the screening arrangement 15 comprises a number of screens 16, of which at least the first screen (seen in a downstream direction) typically requires a mass concentration of about 3-5 % (or even lower).
  • the dilution of the pulp coming from the discharge tank 2 takes place before the inlet 12 of the screen feed pump 13, and more particularly such that the pulp pumped by the discharge tank pump 7 is fed into the dilution liquid flow from the dilution tank 9.
  • the connection between the dilution tank 9 and the screen feed pump 13 comprises a three-way pipe, the third opening of which is connected to the discharge tank pump 7.
  • the dilution tank 9 is also a reject tank, in which reject, via a pipe 22, coming from one or more of the screens 16 of the screening arrangement 15 is collected.
  • the reject has typically a low mass concentration, e.g.
  • the dilution tank is separate tank, or a tank which is connected to other parts of a pulping production system.
  • a corresponding method for feeding the screen feed arrangement (1) with pulp comprises the steps of feeding pulp into a discharge tank (2) via an inlet (3) arranged in a top portion of the discharge tank (2), pumping pulp from the discharge tank (2) via an outlet (4) arranged in a bottom portion (5) of the discharge tank (2) by a discharge tank pump (7) to an inlet (12) of a screen feed pump (13), diluting the pulp at the inlet (12) of the screen feed pump (13) with fluid from an outlet (1 1) of a dilution tank (9), feeding the screen feed arrangement (1) with diluted pulp from an outlet (14) of the screen feed pump (13), wherein the method is characterized in that the pulp at the inlet (6) of the discharge tank pump (7) has a mass concentration of about 8 % to 15 %.
  • the mass concentration of pulp entering a discharge tank is typically stable, at least seen in a relatively long time perspective, and since the mass concentration prevails also at the exit of the discharge tank when employing the present invention, the regulation has in practice by the present invention been moved or transformed from regulation of mass concentration of pulp leaving the discharge tank to regulation based on flow, which is a less challenging technical task. It should, however, be appreciated that the ultimate goal also for the present invention is a regulation of mass concentration, i.e.
  • regulation of the amount of pulp from the discharge tank is in the present invention directed to regulation of pulp flow, rather than regulation of mass concentration, which is a favorable situation since the regulation of flow is relatively easier to accomplish than regulation of mass concentration.
  • the main regulation is directed to the flow of dilution liquid coming from the dilution tank. Since the dilution tank typically is smaller, than a discharge tank, the regulation of flow from the dilution tank is typically easier to accomplish than regulation of flow from a discharge tank. Because of the typically smaller dimension of a dilution tank in comparison with a discharge tank, it is further relatively easier to dimension a screen feed pump with respect to the requirements of a screening arrangement, including its pressure classes and tubing between individual screens.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Paper (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)

Abstract

La présente invention concerne un agencement d'alimentation de classeur pour un procédé de production de pâte à papier, comprenant une cuve de décharge ayant une sortie, qui est raccordée à une entrée d'une pompe de cuve de décharge ayant une sortie, une cuve de dilution ayant une sortie, une pompe d'alimentation de classeur ayant une entrée et une sortie, et un agencement de criblage, dans lequel la sortie de la cuve de décharge et la sortie de la cuve de dilution sont raccordées à l'entrée de la pompe d'alimentation de classeur, dont la sortie est raccordée à l'agencement de criblage, et la pâte à papier qui traverse la sortie de la cuve de décharge a une concentration en masse d'environ 8 % à environ 15 %. L'invention concerne en outre un procédé correspondant pour alimenter une pâte à papier dans un agencement d'alimentation de classeur.
EP17775982.6A 2016-03-30 2017-03-13 Agencement d'alimentation de classeur Withdrawn EP3436634A4 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE1650410A SE1650410A1 (en) 2016-03-30 2016-03-30 Screen feed arrangement
PCT/SE2017/050240 WO2017171608A1 (fr) 2016-03-30 2017-03-13 Agencement d'alimentation de classeur

Publications (2)

Publication Number Publication Date
EP3436634A1 true EP3436634A1 (fr) 2019-02-06
EP3436634A4 EP3436634A4 (fr) 2019-11-06

Family

ID=59966202

Family Applications (1)

Application Number Title Priority Date Filing Date
EP17775982.6A Withdrawn EP3436634A4 (fr) 2016-03-30 2017-03-13 Agencement d'alimentation de classeur

Country Status (7)

Country Link
US (1) US20190127912A1 (fr)
EP (1) EP3436634A4 (fr)
BR (1) BR112018014577A2 (fr)
CL (1) CL2018002693A1 (fr)
RU (1) RU2018138008A (fr)
SE (1) SE1650410A1 (fr)
WO (1) WO2017171608A1 (fr)

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4999085A (en) * 1988-10-06 1991-03-12 Sunds Defibrator Rauma Oy Method for screening of defibered chlorine dioxide bleached pulp during alkaline extraction
DE4125513A1 (de) * 1991-08-01 1993-02-04 Escher Wyss Gmbh Verfahren zum vermischen von suspendiertem faserstoff sowie vorrichtungen zu dessen ausfuehrung
FI93748B (fi) * 1992-06-09 1995-02-15 Ahlstroem Oy Tapa ja laitteisto kuitususpension käsittelemiseksi
FI108150B (fi) * 1999-02-15 2001-11-30 Sulzer Pumpen Ag Menetelmä ja laitteisto massan käsittelemiseksi
FI20031164L (fi) * 2003-07-09 2005-01-10 Sulzer Pumpen Ag Menetelmä ja laitteisto massan käsittelemiseksi
DE102004054236B4 (de) * 2004-11-10 2007-06-06 Voith Patent Gmbh Verfahren zum Mischen von Suspensionen mit unterschiedlichen Zusammensetzungen
CN201416126Y (zh) * 2009-05-26 2010-03-03 山东杰锋机械制造有限公司 网前流送压力筛的控制系统
CN103154361B (zh) * 2010-10-13 2015-09-09 安德里兹公司 用于处理纸浆的装置和方法
WO2014184443A1 (fr) * 2013-05-15 2014-11-20 Andritz Oy Système et procédé pour réguler la consistance dans un réservoir de décharge ou de pâte

Also Published As

Publication number Publication date
WO2017171608A1 (fr) 2017-10-05
BR112018014577A2 (pt) 2018-12-11
US20190127912A1 (en) 2019-05-02
CL2018002693A1 (es) 2018-11-16
RU2018138008A (ru) 2020-04-30
EP3436634A4 (fr) 2019-11-06
SE1650410A1 (en) 2017-10-01

Similar Documents

Publication Publication Date Title
EP1308554B1 (fr) Réduction des matières solides dissoutes pendant la production de pate à papier
EP2260144B1 (fr) Procédé et dispositif pour le dosage proportionnel de pâte épaisse dans un circuit court d une machine à bande de fibres
DE68928632T2 (de) Verfahren und Vorrichtung zum Behandeln von Faserbrei
EP0937813A2 (fr) Amélioration de la réduction du bois en pâte avec contrÔle des solides dissouds
JP4951615B2 (ja) チップ及び液体から成るスラリーの供給装置
US5824188A (en) Method of controlling the pressure of a continuous digester using an extraction-dilution
US20010000588A1 (en) Method and device for the continuous cooking of chemical pulp
US20190127912A1 (en) Screen feed arrangement
EP2193233B1 (fr) Appareil destiné à évacuer de la pâte à partir d'un récipient, procédé d'évacuation de pâte à partir d'un récipient et procédé de mise à niveau d'un récipient à pâte
EP2531644B1 (fr) Procédé de commande des écoulements de filtrats et de stockage des filtrats d'une chaîne de fibres dans une usine de pâte à papier
CA2715011C (fr) Systeme d'alimentation comportant des pompes en parallele pour un digesteur continu
US20050061460A1 (en) Method and arrangement for oxygen delignification of cellulose pulp
US8709211B2 (en) Feeding system having pumps in parallel for a continuous digester
WO2009116946A1 (fr) Système d'alimentation comportant des pompes parallèles pour un digesteur continu
RU2352700C2 (ru) Способ и устройство для переработки целлюлозы
US20230243096A1 (en) System and chip chute for feeding comminuted cellulosic material
US20170022664A1 (en) Method of digesting cellulose fibrous material in a continuous digester
JP2004339682A (ja) 気相式と満液式の連続蒸解缶に用いるトップセパレーターおよび蒸解缶運転モードの転換方法
US8702909B2 (en) Feeding system having pumps in parallel and individual flows for a digester
WO1996034144A1 (fr) Alimentation en matieres fibreuses broyees et deversement de ces matieres
WO2007013851A1 (fr) Systeme et procede de traitement de pate cellulosique en association au vidage d'un lessiveur en continu
CN101755090A (zh) 用于处理纸浆的方法

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

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

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

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20181030

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
A4 Supplementary search report drawn up and despatched

Effective date: 20191004

RIC1 Information provided on ipc code assigned before grant

Ipc: D21D 5/28 20060101AFI20190927BHEP

Ipc: D21C 7/06 20060101ALI20190927BHEP

Ipc: D21D 5/02 20060101ALI20190927BHEP

Ipc: D21C 7/08 20060101ALI20190927BHEP

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20200603