EP0400020A1 - Plaque de tamis - Google Patents

Plaque de tamis

Info

Publication number
EP0400020A1
EP0400020A1 EP19890901144 EP89901144A EP0400020A1 EP 0400020 A1 EP0400020 A1 EP 0400020A1 EP 19890901144 EP19890901144 EP 19890901144 EP 89901144 A EP89901144 A EP 89901144A EP 0400020 A1 EP0400020 A1 EP 0400020A1
Authority
EP
European Patent Office
Prior art keywords
holes
rows
screen
screen plate
grooves
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Withdrawn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
EP19890901144
Other languages
German (de)
English (en)
Inventor
Karl Johan GRUNDSTRÖM
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.)
KNUTSILPLATAR AB
Original Assignee
KNUTSILPLATAR 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 KNUTSILPLATAR AB filed Critical KNUTSILPLATAR AB
Publication of EP0400020A1 publication Critical patent/EP0400020A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
    • B01D29/01—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements
    • B01D29/03—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements self-supporting
    • 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
    • D21D5/16—Cylinders and plates for screens

Definitions

  • This invention relates to a screen plate to be used in apparatuses for screening or fractionating fibre material suspensions, especially suspensions of paper- making pulp.
  • the screen plate is of the type provided with screen holes arranged in rows substantially per ⁇ pendicular to the flow direction in the apparatus.
  • the European patent application with publication number 2 6 8 3 discloses a screen plate, which is provided with circular screen holes located in the bottom of parallel grooves in the plate.
  • the essential feature of the screen plate according to said application is, that the grooves shall be formed in a special way, viz. so that their "walls" shall form a certain definite angle with the surface of the plate, and the bottom of the grooves shall have a certain width in relation to the diameter of the screen holes.
  • the European patent application with publication number 79 8ll also discloses a screen plate with the screen holes arranged in parallel grooves. At least one wall in the grooves extends in radial direction perpendicular to the flow direction of the suspension.
  • the present invention eliminates these disadvantages.
  • the screen plate comprises between the rows of screen holes substantially plane unperforated surfaces for the erection of shives and other impurities.
  • the holes have substanti ⁇ ally circular cross-section and are located in the bottom of parallel grooves.
  • the surfaces are provided with turbulence-forming and thereby capacity-increasing grooves or protuberances, so-called warts.
  • grooves should be arranged substantially in parallel and should extend in the flow direction of the suspension or at an angle there ⁇ to.
  • the grooves can be arched, for example by milling.
  • the screen holes can be circular, but may also have another cross-sectional shape, for ex ⁇ ample be formed as slits.
  • Fig. 1 schemat ⁇ ically shows a screen plate with inserted designations tl, t2 and D
  • Fig. 2 also schematically shows how the grooves can be arranged
  • Figs ' . 3 and 4 show an arrange ⁇ ment where the screen holes are located in the bottom of grooves
  • Fig; 5 is a diagram showing the technical effect obtained according to the invention.
  • a screen plate 1 with circular holes 2 is shown.
  • the designations tl, t2 and D are identical with the ones specified above.
  • Fig. 2 is shown how the grooves can be arranged in the erection distances, either in parallel with the flow direction of the sus ⁇ pension as at 6, perpendicular thereto as at 3 or at a certain arbitrary angle as at 4 and 5.
  • Figs. 3 and 4 a particularly advantageous embodiment is shown.
  • the screen holes 2 here are located in the bottom of grooves 7 3 which in the Figure are shown to be parallel.
  • the grooves 8 according to this embodiment have saw-toothed cross-section, but may, of course, have another shape and be located at greater distances and may have varying depth.
  • the paper technology develops toward processes, which require fibre compositions of greater homogeneity.
  • the screening technique in this respect is of decisive im ⁇ portance, and the perforation and surface geometry of the screen plates used in the screens is essential for the result achieved.
  • the screen plate according to the invention renders it possible to separate shives and other oblong impurities with high selectivity. At fibre fractionation long fibres easily can be separated from short ones.
  • the erection distances arranged on the screen plate according to the invention imply improved shives separ ⁇ ation and increase fine-scale turbulence at the screen plate surface.
  • Shives and oblong impurities are erected and oriented between the rotating cleaning drum and stationary screen basket.
  • the shives most often are sep ⁇ arated due to their length and, therefore, are to be oriented so as to be located over the screen hole.
  • Such erection and orientation is facilitated substant ⁇ ially by the screen plate according to the invention, at the same time as the turbulence intensity and thereby the capacity increase.
  • the members producing turbulence in the orientation distances give rise to fluidization of the fibre sus ⁇ pension. Fluidization implies that the fibres are freely movable in relation to each other and prevent mechanical binding of impurities to the fibre material.
  • shives orientate in the fluidized fibre suspension between the hole rows.
  • the unperfor ⁇ ated distances prevent thickening of the suspension when long shives orientate in the shear field in front of the screen basket.
  • the screening process is divided into two phases, viz. the orientation phase and the phase of passage through the holes.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Paper (AREA)
  • Combined Means For Separation Of Solids (AREA)

Abstract

Une plaque de tamis permet de tamiser ou de fractionner des suspensions fibreuses, notamment des suspensions de pâte à papier, laquelle plaque de tamis est du type où les trous de tamisage sont agencés en rangées sensiblement perpendiculaires au sens d'écoulement de la suspension. Afin d'accroître l'efficacité du tamis, celui-ci comporte des surfaces planes non ajourées (3, 4, 5, 6, 8) destinées à rejeter les bûchettes et autres impuretés, et les écartements entre les rangées sont sensiblement supérieurs aux écartements mutuels entre les trous dans les rangées.
EP19890901144 1988-01-15 1988-12-29 Plaque de tamis Withdrawn EP0400020A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8800114 1988-01-15
SE8800114A SE458772B (sv) 1988-01-15 1988-01-15 Silplaat

Publications (1)

Publication Number Publication Date
EP0400020A1 true EP0400020A1 (fr) 1990-12-05

Family

ID=20371078

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890901144 Withdrawn EP0400020A1 (fr) 1988-01-15 1988-12-29 Plaque de tamis

Country Status (4)

Country Link
EP (1) EP0400020A1 (fr)
FI (1) FI903576A0 (fr)
SE (1) SE458772B (fr)
WO (1) WO1989006719A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IL95940A0 (en) * 1990-03-08 1991-07-18 Technicon Instr In-line fluid filter for an automated analyzer
SE505400C2 (sv) * 1995-11-08 1997-08-18 Capricell Ab Barriär för avvattning av fibersuspensioner

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2827169A (en) * 1954-12-07 1958-03-18 Internat Pulp Products Inc Screen plate
SE374400B (fr) * 1972-08-31 1975-03-03 Svenska Cellulosa Ab
FR2516563A1 (fr) * 1981-11-18 1983-05-20 Lamort E & M Perfectionnements aux epurateurs de pate a papier et a leurs tamis
DE3607457A1 (de) * 1986-03-07 1987-09-10 Voith Gmbh J M Sortiersieb

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8906719A1 *

Also Published As

Publication number Publication date
FI903576A0 (fi) 1990-07-13
WO1989006719A1 (fr) 1989-07-27
SE8800114D0 (sv) 1988-01-15
SE458772B (sv) 1989-05-08

Similar Documents

Publication Publication Date Title
US4276159A (en) Apparatus for screening paper fiber stock
CA1136585A (fr) Tamis cylindrique a minces fentes et racloirs rotatifs concourants pour la separation par haute turbulence
US3581903A (en) Separator for paper pulp suspensions
JPH0115633B2 (fr)
EP0624684B1 (fr) Cylindre pour épurateur
EP0637348B2 (fr) Appareil de traitement de suspensions fibreuses
JPH0133598B2 (fr)
JPS5831190A (ja) 繊維生地をばらしてふるい分けする装置
CA2154258C (fr) Appareil de classage de pate a papier
GB2195911A (en) Screening apparatus for pulp
EP0400020A1 (fr) Plaque de tamis
US8584865B2 (en) Screen
EP0261117B1 (fr) Element rotatif pour un appareil de tamisage muni d'une surface de contour
JPH089838B2 (ja) 繊維懸濁液を濃化する方法と装置
IE892269A1 (en) Screening apparatus
JPH0536553B2 (fr)
US5156750A (en) Method and apparatus for thickening a fiber suspension and removing fine particles therefrom
CA1157427A (fr) Crible vibratoire a toile autostable
SU859520A1 (ru) Фильтрующий элемент щелевого сита дл волокнистой суспензии
SU1058514A3 (ru) Шлицевое цилиндрическое сито узлоловител дл очистки бумажной массы
SU1373742A1 (ru) Сито дл сортировани волокнистой суспензии
JP2004538137A (ja) 叩解部材
JPH0536554B2 (fr)
SU863739A1 (ru) Сортирующее сито дл очистки волокнистой массы
JPH01501765A (ja) 円筒スクリ−ン

Legal Events

Date Code Title Description
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

17P Request for examination filed

Effective date: 19900522

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB

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: 19910703