EP0267327A1 - Tamis sous pression pour suspensions de fibres - Google Patents

Tamis sous pression pour suspensions de fibres Download PDF

Info

Publication number
EP0267327A1
EP0267327A1 EP86116609A EP86116609A EP0267327A1 EP 0267327 A1 EP0267327 A1 EP 0267327A1 EP 86116609 A EP86116609 A EP 86116609A EP 86116609 A EP86116609 A EP 86116609A EP 0267327 A1 EP0267327 A1 EP 0267327A1
Authority
EP
European Patent Office
Prior art keywords
sorter according
pressure sorter
pressure
screen
inflow space
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Withdrawn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
EP86116609A
Other languages
German (de)
English (en)
Inventor
Emil Holz
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.)
Voith Finckh Fiber Systems GmbH and Co KG
Original Assignee
Hermann Finckh Maschinenfabrik GmbH and Co
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 Hermann Finckh Maschinenfabrik GmbH and Co filed Critical Hermann Finckh Maschinenfabrik GmbH and Co
Publication of EP0267327A1 publication Critical patent/EP0267327A1/fr
Withdrawn legal-status Critical Current

Links

Images

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
    • D21D5/023—Stationary screen-drums

Definitions

  • the invention relates to a pressure sorter for fiber suspensions, with a housing in which a first, formed as a sieve, defining an axis stationary ring wall and a second ring wall between them enclose an annular inflow space, the one, first end with a housing inlet and the other, the second The end is connected to a reject outlet of the housing, the two ring walls being designed in such a way that the cross-sectional area of the inflow space decreases on average perpendicular to the sieve axis in the axial direction from its first to its second end, as well as with a suspension feed pump connected to the housing inlet and with Surface irregularities on at least one of the ring wall surfaces delimiting the inflow space.
  • the housing accommodates a stationary, circular-cylindrical screen basket and a rotor surrounded by the latter, which is provided with so-called cleaning blades that circulate in the immediate vicinity of the screen surface formed by the screen basket and thereby generate pressure and suction impulses at the screen openings, which counteract clogging of the screen openings by fibers and impurities.
  • cleaning blades that circulate in the immediate vicinity of the screen surface formed by the screen basket and thereby generate pressure and suction impulses at the screen openings, which counteract clogging of the screen openings by fibers and impurities.
  • the invention was therefore based on the object of developing a pressure sorter which, when installed before a pressure headbox, reduces the risk of pressure fluctuations occurring in the headbox.
  • a pressure sorter of the type mentioned at the outset was used, as it is e.g. is described in DE-OS 20 27 028.
  • a drum-shaped rotor with a closed, truncated-cone-shaped jacket rotates within a stationary, circular-cylindrical screen basket, the outer peripheral surface of which is provided with hemispherical projections.
  • the fiber suspension to be sorted flows into the inflow space between the rotor and screen basket from above, and due to the frustoconical shape of the rotor, the annular chamber-shaped inflow space tapers from top to bottom.
  • the projections on the outer peripheral surface of the rotor serve the same purpose as the cleaning blades of the known pressure sorters described above, so that even when using the pressure sorter according to DE-OS 20 27 028 before a pressure headbox there is a risk of causing pressure fluctuations in the latter by the pressure sorter .
  • the invention proposes to design a pressure sorter of the type mentioned at the outset in such a way that the second ring wall is also stationary and that the delivery capacity of the suspension feed pump and the cross section of the inflow space and the surface irregularities are matched to one another in such a way that the fiber suspension with a such a high flow velocity flows over the surface unevenness that turbulence which prevents the sieve openings from becoming blocked can be generated by the latter.
  • the principle according to the invention has a number of advantages: the energy required for the operation of the known pressure sorters described, which is required for driving the rotor or the rotating screen basket, and there is also no one or more shaft seals for a rotor or screen basket drive shaft.
  • the second ring wall of the pressure sorter according to the invention can be a second sieve, but it can also be a closed surface, e.g. the outer or inner peripheral wall of a body similar to a rotor, but which does not rotate.
  • the decrease in the cross-sectional area of the inflow space in the direction of the reject outlet can result from the fact that one annular wall is cylindrical and the other is conical, as is the case with the known pressure sorter according to DE-OS 20 27 028; however, an embodiment is preferred in which both ring walls are conical, so that the change in the cross-sectional area results from the change in the radii.
  • DE-OS 20 27 028 shows a circular cylindrical sieve basket
  • the prior art also discloses a pressure sorter with a stationary, truncated cone-shaped sieve basket, which is directed towards the rejects outlet is tapered and surrounded by a second, conical ring wall which, together with the strainer basket, forms an inflow space which tapers in the direction of the spit outlet (US Pat. No. 3,394,809).
  • the cleaning of the screen openings is served by a driven rotor, arranged in the inside of the screen basket, with cleaning blades, and the screen and outer, second ring wall have smooth surfaces.
  • the sieve and the outer, second ring wall have different conicity, which is why there is a relatively large radial width at the end of the inflow space facing the housing inlet.
  • depressions are provided on the inflow side, each of which opens into a sieve opening and are arranged offset with respect to the sieve openings in the direction of flow and have oblique side walls tapering towards the sieve openings in order to prevent long-fiber contaminations which form a sieve surface Approach the flow direction, which does not run parallel, but obliquely to the screen surface, impinge on the peripheral wall of the actual screen openings and are thus deflected into the latter.
  • both ring wall surfaces have such surface unevenness.
  • a pressure sorter in which the two ring walls are conical and have the same conicity has proven to be a particularly efficient embodiment with regard to keeping the sieve openings open, so that in order to maintain a high flow velocity over the uneven surfaces, the outflow of fiber suspension through the sieve openings with respect to the inflow space Volume is compensated for by the fact that, with the width of the inflow space remaining the same, its diameter becomes smaller and smaller in the direction of the reject outlet.
  • the gap width between the two ring walls i.e. the radial width of the inflow space is adjustable, which can be most easily achieved in a pressure sorter, the two ring walls of which are conical and have the same conicity, in that the two ring walls are adjustable relative to one another in the axial direction, which of course is sufficient, one of the to be able to move and adjust both ring walls in the axial direction.
  • a ring wall adjustment drive which can be controlled as a function of the delivery rate of the pump, is then particularly advantageous.
  • the power consumption of the feed pump can serve as the manipulated variable, but it would also be conceivable, for example, to measure the flow rate of the fiber suspension through the feed pump and to control the ring wall adjustment drive with the measurement signal thus generated.
  • the second ring wall can have a closed surface or can also be designed as a sieve;
  • the embodiment mentioned in the second has the advantage of large throughput quantities of fiber suspension, but generally requires a higher proportion of rejects in order to be able to generate sufficiently large turbulence in the area of the screen openings of both screens.
  • the pressure sorter shown in FIGS. 1 to 3 has a housing 10 which is closed except for three connections and which has an inlet 12, an accept substance outlet 14 and a reject substance outlet 16.
  • the housing 10 - apart from the various housing connections - is designed to be rotationally symmetrical about an axis 18.
  • a rotationally symmetrical, conical strainer basket 20 is firmly attached, concentrically to the axis 18.
  • the strainer openings have been designated 22.
  • a displacement body 24 is likewise mounted concentrically to the axis 18, but is adjustable in the housing 10 along this axis.
  • a shaft 32 carrying the casing 26, 28 of the displacer 24 projects with an upper shaft end 32a provided with a spline in a guide tube 34 of the housing 10, which is provided in its lower region with a corresponding spline 34a on the inside, so that the shaft 32 in Guide tube 34 is guided longitudinally displaceable, but is secured against rotation.
  • O-rings 36 serve to seal the guide tube 34, and the following gear elements are provided for displacing the displacement body 24 downwards: a threaded bore 38 in the upper end of the shaft 32, a threaded spindle 40 engaging in this threaded bore, which carries a worm wheel 42, and a worm 44 meshing with the latter, which is fastened on the output shaft of a geared motor 46 shown offset by 90 °.
  • the threaded spindle 40 is axially non-displaceably mounted in a manner not shown, but it could also engage in a threaded bore of a cover fixedly attached to the housing and be rotatably but axially non-displaceably mounted in the shaft 32.
  • the fiber suspension to be sorted or sifted is fed by means of a feed pump 48 with an inlet pressure p; fed at least 1.5 bar into inlet 12 of the pressure sorter housing;
  • the feed pump 48 is preferably a speed-controlled pump with a speed controller 50, which is connected via a control line 52 to the gear motor 46, so that the displacement body 24 is axially dependent on the amount of fiber suspension fed into the pressure sorter per unit time Direction can be adjusted.
  • the shaft 32 With its lower end 32b, the shaft 32 is held in a longitudinally displaceable manner in an outlet piece 54 fastened to the bottom of the housing 10, this outlet piece being designed in such a way that it forms an annular space 56 around the shaft 32, which forms at the lower end of the inflow space 30 connects and into which the rejects outlet 16 opens.
  • the sieve openings 22 are designed as circular holes which have frustoconical countersinks 60 and 62 on the inner or Connect the inflow side and the outlet side of the screen basket 20.
  • FIG. 3 also shows that the counterbores 60 on the inflow side are arranged offset slightly downward from the screen openings 22.
  • the flow course of the fiber suspension in the pressure sorter was indicated with arrows.
  • the fiber suspension fed into the pressure sorter through the inlet 12 flows into the inflow space 30 from above at a speed V1 , and that part of the fiber suspension which passes through the screen openings 22 flows through them at the speed v 2 and thus arrives in an accepting material space 64. which leads to the accept substance outlet 14.
  • That part of the fiber suspension that does not pass through the screen openings 22, namely the so-called rejects flows into the outlet piece 54 at the lower end of the inflow space 30 and leaves the pressure sorter via the rejects outlet 16.
  • the pressure sorter is designed with regard to the delivery capacity of the pump 48, the dimensions of the inflow space 30 and the number and size of the sieve openings 22 such that the flow velocity V1 of the fiber suspension in the inflow space 30 is approximately the same everywhere and is approximately 8 to 20 m / s is, while the speed at which the accepted material flows through the screen openings 22 is preferably in the range between 0.2 and 2 m / s, in particular approximately 1 m / s; the inlet pressure p ; should be at least 1.5 bar if the pressure loss in the inflow area of the housing 10 and on the displacement body 24 is approximately 0.5 bar and the pressure loss on the strainer basket is also approximately 0.5 bar.
  • the construction should be designed such that the amount of the acceptor leaving the pressure sorter via the acceptor outlet 14 to the amount of the reject leaving the pressure sorter via the reject outlet 16 is approximately 10: 1, preferably approximately 9: 1.
  • the mean diameter of the strainer basket 20 is approximately 500 mm, and it is advisable to adjust the displacer 24 approximately so that the radial width of the inflow space 30 is approximately 2 cm.
  • FIGS. 4 to 6 will now only be described to the extent that they differ in essential features from the embodiment according to FIGS. 1 to 3.
  • a conical jacket 28 'of a housing 10' which has an inlet 12 ', an accept substance outlet 14' and a reject substance outlet 16 'provided with a valve 16a', forms the second ring wall in the sense of the claims and together limits an inflow space 30 'with a conical strainer basket 20' closed at the bottom.
  • the pipe socket forming the inlet 12 ' is to run tangentially to the jacket 28', so that - also as a result of a collar 12a 'forming part of an annular web - a helical flow through the inflow space 30' from top to bottom is ensured.
  • This helical flow was indicated by arrows V1 .
  • nubs 70 ' are provided on the inside of the casing 28', and the strainer basket 20 'is fixedly connected to the housing 10' via a non-perforated upper region 20a 'and a collar 20b'.
  • FIG. 5 is a pressure sorter in which the two ring walls delimiting the inflow space are designed as sieves.
  • a housing 10 "holds an inner, first screen basket 20” and an outer, second screen basket 28 “, both of which have the same taper and are arranged concentrically to an axis 18" of the pressure sorter.
  • the latter again has an inlet 12 ′′, an accept substance outlet 14 ′′ and a rejects outlet 16 ′′.
  • At least one of the two truncated cone surfaces delimiting an inflow space 30 ′′ is again provided with uneven surfaces, not shown.
  • the outer screen basket 28 has a largest diameter of approximately 620 mm and a smallest diameter of approximately 120 mm in this pressure sorter, while the inner screen basket 20" has a largest diameter of approximately 600 mm and a smallest diameter of approximately 100 mm, so that the radial width of the annular inflow space 30 "is approx. 20 mm.
  • the height of the two screen baskets is approx. 1200 mm. It is advisable to operate this pressure sorter in such a way that the flow velocity of the fiber suspension in the inflow space 30" (vi) is greater than 10 m / s. Because of the use of two sieve baskets, larger throughputs can be achieved with this pressure sorter than with the pressure sorters according to FIGS. 1 to 4, but it is necessary to operate the pressure sorter in such a way that a higher proportion of rejects occurs (approx. 20% instead of approx. 10%).
  • the pressure sorter shown in FIG. 6 differs from that according to FIG. 5 only in that the inner strainer basket 20 "is height-adjustable (by means of adjustment means, not shown).
  • the outer strainer basket 28" ends on a vertical ring wall 10a "of the housing 10" , and the inner strainer basket 20 “again has a non-perforated upper area 20a” and a collar 20b ", the latter of which lies sealed against the ring wall 10a".
  • the inlet of the housing 10 was designated 12", the accept outlet 14 "and the reject outlet 16".
  • the pressure sorters according to the invention lead to a pulsation-free headbox, are maintenance-free, have no rotating parts, consequently also do not require problematic seals for rotating parts, that a drive and the energy required for this are eliminated and that they entail lower investment costs than conventional pressure sorters.
  • the pressure sorter according to the invention could also be designed so that it has a horizontal axis, i.e. that it is arranged lying down.
  • the surface unevenness provided according to the invention cause local speed changes and thus turbulence in the fiber suspension to be sorted.
  • the conicity of the two ring walls delimiting the inflow space is selected such that, according to the invention, the flow speed of the fiber suspension to be sorted in the direction of the sieve axis is approximately the same size from the inflow end of the inflow space to its outflow end.
  • the conicity of the ring walls delimiting the inflow space is chosen so that the flow rate of the fiber suspension to be sorted even increases from the inflow end of the inflow space to the outflow end thereof, in order to counteract an increasing accumulation of impurities in the fiber suspension in the direction of the rejects outlet .
  • the reject outlet is always open (possibly with a throttling effect).

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Paper (AREA)
  • Combined Means For Separation Of Solids (AREA)
EP86116609A 1986-11-13 1986-11-28 Tamis sous pression pour suspensions de fibres Withdrawn EP0267327A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3638846 1986-11-13
DE3638846 1986-11-13

Publications (1)

Publication Number Publication Date
EP0267327A1 true EP0267327A1 (fr) 1988-05-18

Family

ID=6313905

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86116609A Withdrawn EP0267327A1 (fr) 1986-11-13 1986-11-28 Tamis sous pression pour suspensions de fibres

Country Status (1)

Country Link
EP (1) EP0267327A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2245842A (en) * 1990-07-13 1992-01-15 Patrick Joseph Tierney Cross-flow filter
EP0522378A1 (fr) * 1991-07-12 1993-01-13 J.M. Voith GmbH Cribleur à pression
DE4432842A1 (de) * 1994-09-15 1996-03-28 Voith Sulzer Stoffaufbereitung Verfahren zum Ausbringen unerwünschter Feststoffpartikel aus einer wässerigen Faserstoffsuspension sowie Vorrichtung zu seiner Ausführung
EP0938358A1 (fr) * 1996-09-02 1999-09-01 Davidson, Clifford M. Filtre
WO2016193942A1 (fr) * 2015-06-04 2016-12-08 GL&V Luxembourg S.à.r.l. Trieur de nœuds sous pression sans rotor

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1448814A (fr) * 1965-04-15 1966-08-12 Ingersoll Rand Canada Appareil de tamisage
FR1471118A (fr) * 1966-03-14 1967-02-24 Procédé de séparation de solides
US3394809A (en) * 1965-01-25 1968-07-30 Hunter Allen Bruce Pulp screens
DE2511632A1 (de) * 1975-03-17 1976-09-30 Werner Renz Vorrichtung zum abtrennen suspendierter und/oder geloester stoffe aus fluessigkeiten
GB2088235A (en) * 1980-12-02 1982-06-09 Jensen Hartvig Co As Self-cleaning Filter
FR2499876A1 (fr) * 1981-02-18 1982-08-20 Andritz Ag Maschf Trieuse de matieres fibreuses en suspension
WO1983002292A1 (fr) * 1981-12-23 1983-07-07 Malm, Karl, Gunnar Plaque de tamis, presse a vis ou analogue pour le traitement d'une suspension

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3394809A (en) * 1965-01-25 1968-07-30 Hunter Allen Bruce Pulp screens
FR1448814A (fr) * 1965-04-15 1966-08-12 Ingersoll Rand Canada Appareil de tamisage
FR1471118A (fr) * 1966-03-14 1967-02-24 Procédé de séparation de solides
DE2511632A1 (de) * 1975-03-17 1976-09-30 Werner Renz Vorrichtung zum abtrennen suspendierter und/oder geloester stoffe aus fluessigkeiten
GB2088235A (en) * 1980-12-02 1982-06-09 Jensen Hartvig Co As Self-cleaning Filter
FR2499876A1 (fr) * 1981-02-18 1982-08-20 Andritz Ag Maschf Trieuse de matieres fibreuses en suspension
WO1983002292A1 (fr) * 1981-12-23 1983-07-07 Malm, Karl, Gunnar Plaque de tamis, presse a vis ou analogue pour le traitement d'une suspension

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2245842A (en) * 1990-07-13 1992-01-15 Patrick Joseph Tierney Cross-flow filter
EP0522378A1 (fr) * 1991-07-12 1993-01-13 J.M. Voith GmbH Cribleur à pression
DE4432842A1 (de) * 1994-09-15 1996-03-28 Voith Sulzer Stoffaufbereitung Verfahren zum Ausbringen unerwünschter Feststoffpartikel aus einer wässerigen Faserstoffsuspension sowie Vorrichtung zu seiner Ausführung
EP0938358A1 (fr) * 1996-09-02 1999-09-01 Davidson, Clifford M. Filtre
EP0938358A4 (fr) * 1996-09-02 1999-09-15
WO2016193942A1 (fr) * 2015-06-04 2016-12-08 GL&V Luxembourg S.à.r.l. Trieur de nœuds sous pression sans rotor
US10081912B2 (en) 2015-06-04 2018-09-25 Gl&V Usa Inc. Rotorless pressure knotter

Similar Documents

Publication Publication Date Title
EP1062047B1 (fr) Separateur cyclone
DE1761600C3 (de) Vorrichtung zum Sichten von Faserstoffaufschwemmungen
DE2611885C3 (de) Gerät zur Reinigung von Faserstoffsuspensionen
DE2830386C2 (de) Verfahren zum Sortieren von Fasersuspensionen sowie Drucksortierer zur Durchführung des Verfahrens
DE2712749A1 (de) Sortierer zum sichten von fasersuspensionen
DE2006685A1 (de) Selbstreinigendes Filter
DE3111225A1 (de) "vorrichtung und verfahren zum trennen eines gases von einer fasersuspension"
DE2712715B2 (de) Sortierer für Fasersuspensionen
CH367041A (de) Siebvorrichtung
EP0253006B1 (fr) Trieuse sous pression
EP0456788B1 (fr) Tamis pour trieuse sous pression pour suspensions fibreuses
DE1782775B2 (de) Drehluftsichter. Ausscheidung aus: 1507683
WO1999032209A1 (fr) Filtre modulaire pour liquides
EP0146641A1 (fr) Tamis à trier pour suspensions de fibres de pâte
EP0267327A1 (fr) Tamis sous pression pour suspensions de fibres
EP0235605A2 (fr) Dispositif de tamisage pour pâte à papier
DE2754303C3 (de) Vorrichtung zur Konzentration und/oder Flüssigkeitsbehandlung von flüssigkeitshaltigen Substanzgemischen
DE69912424T2 (de) Siebvorrichtung mit zwei siebkammern zur trennung von fasersuspensionen
DE10115298A1 (de) Drucksortierer zum Entfernen von Störstoffen aus einer störstoffhaltigen Papierfasersuspension
DE102006030905B3 (de) Verfahren zur Abscheidung von Verunreinigungen aus einer Faserstoffsuspension
DE8630472U1 (de) Drucksortierer für Fasersuspensionen
EP0448100A1 (fr) Broyeur-mélangeur
DE2750499B2 (de) Sortierer für Fasersuspension
DE8204088U1 (de) Stoffsortiermaschine
DE3831845C2 (fr)

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

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT DE FR GB IT SE

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

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19880622

RIN1 Information on inventor provided before grant (corrected)

Inventor name: HOLZ, EMIL