WO1998050624A1 - Method and arrangement for controlling a multi-phase screening apparatus - Google Patents
Method and arrangement for controlling a multi-phase screening apparatus Download PDFInfo
- Publication number
- WO1998050624A1 WO1998050624A1 PCT/FI1998/000378 FI9800378W WO9850624A1 WO 1998050624 A1 WO1998050624 A1 WO 1998050624A1 FI 9800378 W FI9800378 W FI 9800378W WO 9850624 A1 WO9850624 A1 WO 9850624A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- accept
- screening
- channels
- flow
- screening apparatus
- Prior art date
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
Definitions
- the invention relates to a method for controlling a multi-step screening apparatus, said method comprising measuring flows of accept and reject channels of the screening apparatus comprising at least two steps, and adjusting their flow by means of regulating valves mounted in the channels.
- the invention further relates to an apparatus for controlling a multi- step screening apparatus, said apparatus comprising a control unit arranged to measure flows of accept and reject channels of the screening apparatus by means of measuring devices provided in the channels, and to regulate accept and reject flows of the screening apparatus by means of regulating valves mounted in the channels.
- Screening apparatuses are used for screening pulp in order to obtain the most suitable pulp for the manufacture of paper or board.
- the screening removes various impurities, such as splinters, any fibre bundles, and other impurities disadvantageous in view of the manufacture and quality of the finished web.
- the screening is performed by screening apparatuses comprising one or more screen cylinders or corresponding members provided with apertures.
- the area and apertures or slots of these cylinders or corresponding members are dimensioned such that the accepted pulp fraction, i.e. accept, is allowed to pass through the apertures of the screen as easily as possible, whereas impurities and fibres that are too big are not allowed to pass therethrough.
- it is very important to achieve as pure accept and as high screening capacity as possible.
- Multi-step screening is thus used to ensure that the desired quality is obtained.
- the apparatuses thus comprise a plurality of operationally successive screening steps.
- the pulp to be screened is usually supplied to the first step of the screening apparatus, i.e. to the coarse screen.
- the coarse screen separates the coarsest material, such as splinters and fibre bundles, from the pulp. This material is removed from the screening apparatus and supplied through channels to a reject container.
- the pulp that has passed through the coarse screening flows to the actual screening steps, in which the pulp that has passed through the screen is supplied through channels to an accept container or the like.
- the reject is diluted with water, if necessary, and supplied to the following screening step, in which the pulp fraction that has passed through the screen drum is recirculated to the accept channel.
- a screening apparatus thus comprises a plurality of successive screens which screen the pulp such that the last reject is finally discharged from the screening apparatus through a channel to the reject container.
- the screening apparatus is controlled by a complicated automation system with a high calculation capacity.
- the aim of the control system is to estimate the internal flows of the screening apparatus by calculating.
- such a control system has proved to be rather complicated and to set high requirements for the capacity of the automation system.
- the object of the present invention is to provide a simpler solution for controlling a multi-step screening apparatus.
- the method of the invention is characterized in that the flows of the reject channels and the other accept channels of the screening apparatus are controlled in relation to the flow of the accept channel of the first step of the screening apparatus.
- the apparatus of the invention is characterized in that the control unit is arranged to control the flows of other accept and reject channels in relation to the flow of the accept channel of the first step of the screening apparatus.
- a basic idea of the invention is that a multi-step screening apparatus is controlled by controlling other accept and reject flows of the screening apparatus in relation to the accept flow of the first screening step, which renders the complicated estimation of internal flows by calculating unnecessary.
- the idea of another embodiment of the invention is that in the steps following the first screening step, dilution water is supplied to the pulp in relation to the accept flow of the first step.
- the idea of yet another embodiment of the invention is that the accept flow of the first step of the screening apparatus is adjusted according to the need of either the feeding or the receiving accept container.
- Figure 1 is a schematic view of a solution of the invention for controlling a multi-step screening apparatus
- Figure 2 is a schematic view of another solution of the invention for controlling a multi-step screening apparatus.
- Figure 1 is a schematic view of a solution of the invention for controlling a multi-step screening apparatus.
- the four-step screening apparatus 1 shown in the figure comprises coarse screening 2 and subsequent primary screening compartments 3a to 3c, which perform the actual screening. Screening apparatuses may also comprise only two or three steps, or they may comprise more than four steps. The number of screening steps required depends on the screening capacity, quality and minimum amount of reject required.
- the pulp to be treated is supplied to the coarse screen 2 of the screening apparatus 1 through a supply channel 4.
- the pulp that has passed through the coarse screen 2 flows to the following screening steps 3a to 3c.
- the material that has not passed through the coarse screen 2, such as splinters and fibre bundles, is removed from the screening apparatus 1 and supplied through a first reject channel 5a to a reject container 6.
- the accept that has passed through is supplied through accept channels 7a to 7c to an accept container 8.
- the pulp that remains after the last screening step 3c is supplied through a second reject channel 5b to a reject container 6.
- the reject obtained after the coarse screening 2 and the reject obtained after screen 3c can be supplied either to the same reject container or separately to different further treatment processes.
- the screening apparatus 1 described above is controlled by a control unit 9, e.g.
- a computer or a programmable logic controller which measures the flow rate and, if necessary, the pressure of all channels 5a to 5b and 7a to 7c, except for the supply channel 4; it also controls the valves mounted in the channels.
- the measuring devices and the valves to be controlled are connected in the figure to the control unit 9 by the same line.
- the control is based on data obtained by measuring the accept channel 7a of the first step 3a. On the basis of these data, the flows of the other channels 5a, 5b and 7b, 7c are regulated to make the screening apparatus operate efficiently and to produce high-quality accept.
- the ratio between the flow of each of the other accept and reject channels 7b, 7c and 5a, 5b and the accept channel 7a of the first step is kept constant.
- the accept channel 7a of the first step is indicated in the figure by a thicker line.
- the flow of the other accept channels 7b, 7c can also be either completely or partly supplied to a container different from the accept container 8 to which the accept flow 7a of the first step is supplied. This is indicated in Figure 2 by broken lines.
- the figure also shows a pulp level measuring means 10, by means of which the amount of accept in the accept container 8 can be monitored.
- FIG. 1 is a schematic view of another solution of the invention for controlling a multi-step screening apparatus.
- the apparatus shown in Figure 2 corresponds to the apparatus illustrated in Figure 1 except that, after the first screening step 3a and the second screening step 3b, dilution water is supplied to the pulp that has not passed through the screen to dilute the mixture and to help the pulp fibres pass through the screen of the following screening step. It is not always necessary to supply dilution water, but in view of the screening it is advantageous in many cases, since more water in relation to fibres usually flows through the screen apertures in the preceding screening steps. Thus the supply of dilution water allows the fibre-water ratio of the pulp that is being screened to be equalized. The flows, and if necessary the pressures, of the dilution water channels 11 a and 11 b are also measured.
- the control unit 9 controls the supply of dilution water in relation to the accept flow of the first screening step 3a.
- Figure 2 also shows a supply container 12, the pulp level of which is measured by another measuring device 13.
- the accept flow 7a of the first screening step can be regulated on the basis of the pulp level data of either the supply container 12 or the accept container 8.
- the flow and pressure of the supply channel 4 do not necessarily have to be measured, and the flow in the channel is not regulated separately at all.
- the screening apparatus may thus vary in its structural details: it may, for example, comprise successive screens that are either plate-like or cylindrical.
Abstract
Description
Claims
Priority Applications (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA002289211A CA2289211A1 (en) | 1997-05-06 | 1998-05-04 | Method and arrangement for controlling a multi-phase screening apparatus |
AT98917176T ATE245224T1 (en) | 1997-05-06 | 1998-05-04 | METHOD AND DEVICE FOR CONTROLLING A MULTIPHASE SCREEN DEVICE |
DE69816453T DE69816453T2 (en) | 1997-05-06 | 1998-05-04 | METHOD AND DEVICE FOR CONTROLLING A MULTI-PHASE SCREEN DEVICE |
AU70484/98A AU7048498A (en) | 1997-05-06 | 1998-05-04 | Method and arrangement for controlling a multi-phase screening apparatus |
KR1019997010238A KR100543048B1 (en) | 1997-05-06 | 1998-05-04 | Method and arrangement for controlling a multi-phase screening apparatus |
EP98917176A EP1007781B1 (en) | 1997-05-06 | 1998-05-04 | Method and arrangement for controlling a multi-phase screening apparatus |
JP54776298A JP2001523311A (en) | 1997-05-06 | 1998-05-04 | Method and apparatus for controlling a multi-stage sorter |
NO19995407A NO314045B1 (en) | 1997-05-06 | 1999-11-04 | Method and apparatus for controlling a multi-stage screen device |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FI971938A FI102550B1 (en) | 1997-05-06 | 1997-05-06 | Method and arrangement for control of a multiphase sorting device |
FI971938 | 1997-05-06 | ||
US5170897P | 1997-07-03 | 1997-07-03 | |
US60/051,708 | 1997-07-03 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1998050624A1 true WO1998050624A1 (en) | 1998-11-12 |
Family
ID=26160385
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/FI1998/000378 WO1998050624A1 (en) | 1997-05-06 | 1998-05-04 | Method and arrangement for controlling a multi-phase screening apparatus |
Country Status (11)
Country | Link |
---|---|
US (2) | US6080274A (en) |
EP (1) | EP1007781B1 (en) |
JP (1) | JP2001523311A (en) |
KR (1) | KR100543048B1 (en) |
AT (1) | ATE245224T1 (en) |
AU (1) | AU7048498A (en) |
CA (1) | CA2289211A1 (en) |
DE (1) | DE69816453T2 (en) |
ES (1) | ES2202837T3 (en) |
NO (1) | NO314045B1 (en) |
WO (1) | WO1998050624A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2001081674A1 (en) * | 2000-04-19 | 2001-11-01 | Pom Technology Oy Ab | Method and arrangement to lead cleaned pulp towards a regulated outlet |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6114466A (en) * | 1998-02-06 | 2000-09-05 | Renal Tech International Llc | Material for purification of physiological liquids of organism |
FI112806B (en) * | 2001-03-09 | 2004-01-15 | Metso Paper Inc | A method for controlling the quality of a pulp |
DE10160603A1 (en) * | 2001-12-10 | 2003-06-26 | Voith Paper Patent Gmbh | Method for regulating sorting systems and sorting system suitable for carrying out this method |
US6788324B2 (en) * | 2002-02-06 | 2004-09-07 | Brady Worldwide, Inc. | Encoder-based control of printhead firing in a label printer |
SE524527E8 (en) * | 2002-06-07 | 2015-10-20 | Metso Paper Inc | Multistage strainer for screening of pulp suspensions |
AT413110B (en) * | 2003-10-15 | 2005-11-15 | Andritz Ag Maschf | SORTER |
DE502004006001D1 (en) * | 2004-03-26 | 2008-03-06 | Ammann Schweiz Ag | SCHWINGSIEBMASCHINE AND METHOD FOR OPERATING A PUNCHING MACHINE |
AT501723B1 (en) | 2005-06-16 | 2006-11-15 | Andritz Ag Maschf | METHOD FOR REMOVING CONTAMINATION FROM FIBROUS SUSPENSIONS |
SE532643C2 (en) * | 2008-07-03 | 2010-03-09 | Metso Paper Inc | Method and apparatus for controlling pulp suspension flow |
KR101771371B1 (en) * | 2016-12-26 | 2017-08-24 | 나성주 | screening machine for screening paper material, casing body for screening machine and screening basket |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1983002470A1 (en) * | 1982-01-08 | 1983-07-21 | Nils Anders Lennart Wikdahl | Method and apparatus in screening fibre suspensions |
WO1993025752A1 (en) * | 1992-06-05 | 1993-12-23 | Sunds Defibrator Industries Aktiebolag | Screening of pulp |
WO1997032078A1 (en) * | 1996-02-29 | 1997-09-04 | Alfa Laval Ab | Process and apparatus for controlling the purification and yield of fibers from a fiber suspension |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4207141A (en) * | 1978-05-09 | 1980-06-10 | Seymour George W | Process for controlling pulp washing systems |
SE431571C (en) * | 1982-07-02 | 1985-04-21 | Nils Anders Lennart Wikdahl | SET FOR CLEANING A FIBER SUSPENSION |
US4994145A (en) * | 1989-03-02 | 1991-02-19 | Seymour George W | Process for producing a constant distribution of a selected property across the width of pulp mat on a pulp washing surface |
AT401112B (en) * | 1993-11-12 | 1996-06-25 | Andritz Patentverwaltung | METHOD AND DEVICE FOR CONTROLLING OR CONTROL OF A SOLID-LIQUID SEPARATION PROCESS |
-
1998
- 1998-04-01 US US09/053,280 patent/US6080274A/en not_active Expired - Fee Related
- 1998-05-04 ES ES98917176T patent/ES2202837T3/en not_active Expired - Lifetime
- 1998-05-04 EP EP98917176A patent/EP1007781B1/en not_active Expired - Lifetime
- 1998-05-04 JP JP54776298A patent/JP2001523311A/en not_active Ceased
- 1998-05-04 AU AU70484/98A patent/AU7048498A/en not_active Abandoned
- 1998-05-04 KR KR1019997010238A patent/KR100543048B1/en not_active IP Right Cessation
- 1998-05-04 CA CA002289211A patent/CA2289211A1/en not_active Abandoned
- 1998-05-04 DE DE69816453T patent/DE69816453T2/en not_active Expired - Lifetime
- 1998-05-04 WO PCT/FI1998/000378 patent/WO1998050624A1/en active IP Right Grant
- 1998-05-04 AT AT98917176T patent/ATE245224T1/en not_active IP Right Cessation
-
1999
- 1999-09-17 US US09/397,950 patent/US6186333B1/en not_active Expired - Fee Related
- 1999-11-04 NO NO19995407A patent/NO314045B1/en not_active IP Right Cessation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1983002470A1 (en) * | 1982-01-08 | 1983-07-21 | Nils Anders Lennart Wikdahl | Method and apparatus in screening fibre suspensions |
WO1993025752A1 (en) * | 1992-06-05 | 1993-12-23 | Sunds Defibrator Industries Aktiebolag | Screening of pulp |
WO1997032078A1 (en) * | 1996-02-29 | 1997-09-04 | Alfa Laval Ab | Process and apparatus for controlling the purification and yield of fibers from a fiber suspension |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2001081674A1 (en) * | 2000-04-19 | 2001-11-01 | Pom Technology Oy Ab | Method and arrangement to lead cleaned pulp towards a regulated outlet |
JP2003531316A (en) * | 2000-04-19 | 2003-10-21 | ポム・テクノロジー・オイ・エービー | Method and apparatus for directing cleaned pulp towards a regulated outlet |
US7141139B2 (en) | 2000-04-19 | 2006-11-28 | Pom Technology Oy Ab | Multiple cleaning stages with various dilution points and accepts recirculated through a common pipe |
Also Published As
Publication number | Publication date |
---|---|
ATE245224T1 (en) | 2003-08-15 |
US6080274A (en) | 2000-06-27 |
NO995407L (en) | 1999-12-06 |
CA2289211A1 (en) | 1998-11-12 |
KR100543048B1 (en) | 2006-01-20 |
DE69816453T2 (en) | 2004-05-27 |
EP1007781B1 (en) | 2003-07-16 |
NO314045B1 (en) | 2003-01-20 |
US6186333B1 (en) | 2001-02-13 |
DE69816453D1 (en) | 2003-08-21 |
ES2202837T3 (en) | 2004-04-01 |
KR20010012286A (en) | 2001-02-15 |
NO995407D0 (en) | 1999-11-04 |
EP1007781A1 (en) | 2000-06-14 |
AU7048498A (en) | 1998-11-27 |
JP2001523311A (en) | 2001-11-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6080274A (en) | Method for controlling a multi-phase screening apparatus | |
JP3301623B2 (en) | Headbox for paper machine | |
US6521089B1 (en) | Process for controlling or regulating the basis weight of a paper or cardboard web | |
US5549792A (en) | Headbox for a paper machine | |
EP0635600B1 (en) | Method and device for regulating a headbox | |
EP1099793B1 (en) | Method and device in the regulation of the headbox | |
JP2001508839A (en) | Method and apparatus for controlling head box in paper machine | |
US5958189A (en) | Wet part of a paper making machine | |
US5466340A (en) | Paper machine headbox and method of controlling pulp material parameters | |
EP1249532B1 (en) | Method and installation for formation control | |
US7077930B2 (en) | Method for controlling screening by measuring flow amount consistency of the pulp | |
US20030041984A1 (en) | Method for controlling quality of pulp | |
US5573642A (en) | Method and device for evening out the basic weight cross section by sectioning the screen circuit | |
WO1993025752A1 (en) | Screening of pulp | |
EP1678373B1 (en) | Method for regulating whiteness for removal of printing ink in deinking installations and deinking installation comprising a flotation cell for removal of printing ink | |
EP3088604B1 (en) | Method and system for the optimization of properties of a multilayer fiber web in fiber web manufacture | |
WO2001065004A1 (en) | Method and arrangement for adjusting pulp consistency | |
EP0620876B1 (en) | Process and device for adjusting the stock supply cross-section at a paper machine head box | |
DE19716146A1 (en) | On-line, localised automatic control of weight profile across a web of paper in the papermaking machine |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AL AM AT AT AU AZ BA BB BG BR BY CA CH CN CU CZ CZ DE DE DK DK EE EE ES FI FI GB GE GH GM GW HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SK SL TJ TM TR TT UA UG US UZ VN YU ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
ENP | Entry into the national phase |
Ref document number: 2289211 Country of ref document: CA Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1998917176 Country of ref document: EP Ref document number: 1019997010238 Country of ref document: KR |
|
ENP | Entry into the national phase |
Ref document number: 1998 547762 Country of ref document: JP Kind code of ref document: A |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
WWP | Wipo information: published in national office |
Ref document number: 1998917176 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1019997010238 Country of ref document: KR |
|
WWG | Wipo information: grant in national office |
Ref document number: 1998917176 Country of ref document: EP |
|
WWG | Wipo information: grant in national office |
Ref document number: 1019997010238 Country of ref document: KR |