EP0453348A1 - Screen for straining a classification of paper pulp - Google Patents

Screen for straining a classification of paper pulp Download PDF

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Publication number
EP0453348A1
EP0453348A1 EP91400922A EP91400922A EP0453348A1 EP 0453348 A1 EP0453348 A1 EP 0453348A1 EP 91400922 A EP91400922 A EP 91400922A EP 91400922 A EP91400922 A EP 91400922A EP 0453348 A1 EP0453348 A1 EP 0453348A1
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EP
European Patent Office
Prior art keywords
screen
purifier
pulp
profile
classifier
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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Withdrawn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
EP91400922A
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German (de)
French (fr)
Inventor
Jean-Pierre Lamort
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.)
Kadant Lamort SAS
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E&M Lamort Fils SA
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Filing date
Publication date
Application filed by E&M Lamort Fils SA filed Critical E&M Lamort Fils SA
Publication of EP0453348A1 publication Critical patent/EP0453348A1/en
Withdrawn legal-status Critical Current

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    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
    • B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
    • B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
    • B07B1/18—Drum screens

Definitions

  • the present invention relates to a screen for a purifier or classifier of paper pulp, and to devices provided with such screens.
  • the sieves generally consist of a flat or cylindrical perforated surface on which a filter dough circulates, the surface being either subjected to vibrations (flat sieves), or swept by a blade which keeps the dough in motion and prevents clogging.
  • the characteristics of the sieves are very variable, in particular according to the initial cleanliness of the pulp to be treated (coarse pulp, pre-purification, fine purification), the average length of the fibers, the concentration of the pulp, the flow of pulp ...
  • the sieves can also be made with thin sheets.
  • a sieving surface constituted by the juxtaposition of U-shaped profiles, sheet metal of the order of 1 to 3 millimeters thick; in this document the bottom of the U is flat and the profiles are juxtaposed so as to form a substantially planar wall; this wall is then machined so as to present, as for sieves with a thick wall, slots or holes accompanied by known obstacles (ribs, grooves, etc.) made in the thickness of the sheet.
  • the invention aims to improve the latter type of sieve. It relates to a sieve for a purifier or classifier of paper pulp of the type constituted by the juxtaposition of elements with a U-shaped cross section in front of which a stirring blade circulates, characterized in that the bottom of the perforated U has a wavy profile with a rounded or angular crest so that the sieving surface in contact with the dough is very significantly increased.
  • the screen is a cylinder made from a sheet of thin thickness, preferably between 1 and 3 millimeters. It is formed of elements 1, folded in a general U shape, and juxtaposed so as to form a sieving wall 2.
  • the cylinder of FIG. 1 can be obtained from elements 1 of the same length, juxtaposed, curved and welded together, or else from an element 1 wound on itself, by forming turns adjacent.
  • the bottom 3 of the U is not flat but deformed longitudinally so as to present, from one wing 4 to the other 5, at least one rounded or angular ridge 20.
  • it then has between the two wings 4,5 a succession of at least two adjacent faces 6,7 adjacent perforated inclined with respect to the general plane 8 of the screen at an angle 12,13 between 0 and 90 °.
  • the bottom of the U thus has a shape at least in V ( Figure 3), or in W ( Figure 2), etc. symmetrical or not, the inclination of two opposite faces 6, 7 can be of the same value or different as shown in Figure 3.
  • the perforations, holes 10 or slots 9, are made on all the inclined faces of the bottom of the U; they are generally made before deformation of the bottom of the U, in particular when the slots are associated with a rib in order to obtain a profile of the obstacle type. However, they can also be produced after the corrugated profile has been formed, in particular when simple slots are produced.
  • This arrangement (of folding the bottom of the U) is to increase the sieving surface for the same width of the U-shaped element, that is to say for the same size of the sieve.
  • This increase in sieving surface means that the same quantity of dough can be processed more quickly.
  • FIG. 2 shows a W-shaped wavy profile with angular ridges. This provision is not limiting and the invention also relates to the profiles in V, or with rounded crest, symmetrical or not ( Figures 3 to 6).
  • the bottom of the U is folded into a symmetrical W shape.
  • the angles 14, 14 ′, 14 "formed between the inclined walls are equal, and of the order of 60 °. This arrangement makes it possible to double the surface 5 of the bottom of the U and therefore to double the surface of the sieve.
  • the wing moves in a direction approximately parallel to the longitudinal axis of the U-shaped elements, perpendicular to the slots 9 for example; the bottom of the U is therefore not at a constant distance from the wing; the top 15 of the top fold (s) of the V in the example of FIG. 2- is closer to the blade than the lateral end 17 of the fold.
  • the present embodiment describes a centripetal cylindrical sieve, but the invention is not limited to this operating mode and also relates to centrifugal sieves.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Paper (AREA)
  • Combined Means For Separation Of Solids (AREA)
  • Filtration Of Liquid (AREA)

Abstract

Screen for a paper pulp purifier or classifier, of the type consisting of the juxtaposition of lengthwise members made of folded thin metal sheet of U-shaped symmetrical overall cross-section, characterised in that the perforated bottom has an undulating profile with a rounded or angular ridge (20) so that the screening area in contact with the pulp is very appreciably increased. <IMAGE>

Description

La présente invention se rapporte à un tamis pour épurateur ou classificateur de pâte à papier, et aux appareils munis de tels tamis.The present invention relates to a screen for a purifier or classifier of paper pulp, and to devices provided with such screens.

Les tamis sont généralement constitués d'une surface perforée plane ou cylindrique sur laquelle circule une pâte à filtrer, la surface étant soit soumise à vibrations (tamis plans), soit balayée par une pale qui maintient la pâte en mouvement et évite le colmatage.The sieves generally consist of a flat or cylindrical perforated surface on which a filter dough circulates, the surface being either subjected to vibrations (flat sieves), or swept by a blade which keeps the dough in motion and prevents clogging.

Les caractéristiques des tamis sont très variables, notamment en fonction de la propreté initiale de la pâte à traiter (pâte grossière, pré-épuration, épuration fine), de la longueur moyenne des fibres, de la concentration de la pâte, du débit de pâte...The characteristics of the sieves are very variable, in particular according to the initial cleanliness of the pulp to be treated (coarse pulp, pre-purification, fine purification), the average length of the fibers, the concentration of the pulp, the flow of pulp ...

La plupart des tamis cylindriques sont réalisés par usinage de plaques métalliques pleines, d'épaisseur de l'ordre de 8 à 10 mm. Cette épaisseur importante améliore la résistance mécanique du cylindre, mais elle augmente les pertes de charges au travers des perforations et contribue à leur colmatage. Il est nécessaire alors de prévoir un dégagement en aval de la perforation, dégagement qu'il faut nettoyer et polir, ce qui élève les coûts de fabrication.Most cylindrical screens are produced by machining solid metal plates, of the order of 8 to 10 mm thick. This large thickness improves the mechanical strength of the cylinder, but it increases the pressure losses through the perforations and contributes to their clogging. It is then necessary to provide a clearance downstream of the perforation, clearance which must be cleaned and polished, which increases the manufacturing costs.

De nombreuses études sont menées pour améliorer les performances de ces tamis; elles ont montré l'influence prépondérante du profil de la surface du tamis devant laquelle la pale se déplace. On a montré par exemple au FR PV n° 116590 que des obstacles disposés perpendiculairement à la trajectoire de la pale permettant de maintenir la turbulence de la pâte et augmentait le débit de tamisage. On a encore montré que la hauteur desdits obstacles améliore également les performances de tamisage (FR 8810684).Many studies are carried out to improve the performance of these sieves; they have shown the predominant influence of the profile of the surface of the sieve in front of which the blade moves. It has been shown for example in FR PV No. 116590 that obstacles arranged perpendicular to the trajectory of the blade making it possible to maintain the turbulence of the dough and increased the screening flow. It has also been shown that the height of said obstacles also improves sieving performance (FR 8810684).

Les tamis peuvent encore être réalisés avec des tôles minces. On a décrit par exemple au brevet EP O 354 846 une surface de tamisage constituée par la juxtaposition de profilés en forme de U, en tôle de l'ordre de 1 à 3 millimètre d'épaisseur; dans ce document le fond du U est plat et les profils sont juxtaposés de façon à former une paroi sensiblement plane; cette paroi est ensuite usinée de manière à présenter comme pour les tamis à paroi épaisse, des fentes ou des trous accompagnés d'obstacles (nervures, rainures,....) connus pratiqués dans l'épaisseur de la tôle.The sieves can also be made with thin sheets. For example, in patent EP 0 354 846, a sieving surface constituted by the juxtaposition of U-shaped profiles, sheet metal of the order of 1 to 3 millimeters thick; in this document the bottom of the U is flat and the profiles are juxtaposed so as to form a substantially planar wall; this wall is then machined so as to present, as for sieves with a thick wall, slots or holes accompanied by known obstacles (ribs, grooves, etc.) made in the thickness of the sheet.

L'invention a pour objectif une amélioration à ce dernier type de tamis. Elle a pour objet un tamis pour épurateur ou classificateur de pâte à papier du type constitué par la juxtaposition d'éléments à section transversale en U devant lesquels circule une pâle d'agitation, caractérisé en ce que le fond du U perforé présente un profil ondulé à crête arrondie ou anguleuse de façon que la surface de tamisage en contact avec la pâte soit augmentée très sensiblement.The invention aims to improve the latter type of sieve. It relates to a sieve for a purifier or classifier of paper pulp of the type constituted by the juxtaposition of elements with a U-shaped cross section in front of which a stirring blade circulates, characterized in that the bottom of the perforated U has a wavy profile with a rounded or angular crest so that the sieving surface in contact with the dough is very significantly increased.

Le tamis, selon l'invention, est encore remarquable par les caractéristiques suivantes :The sieve according to the invention is also remarkable for the following characteristics:

Le fond du U présente :

  • au moins deux parois perforées inclinées successives opposées formant entre elles un angle compris entre 45° et 90°;
  • un profil ondulé en forme de W
  • le profil en W est régulier, d'angles égaux de l'ordre de 60°, la largeur des parois inclinées étant approximativement égales à la demi largeur du U;
  • la hauteur des crêtes du profil ondulé est faible devant la distance séparant le sommet du U à la pale d'agitation du tamis, de telle sorte que la variation de la dépression produite par la pale, le long de la paroi soit insensible.
The bottom of the U presents:
  • at least two opposite successive inclined perforated walls forming between them an angle between 45 ° and 90 °;
  • a W-shaped wavy profile
  • the W profile is regular, with equal angles of the order of 60 °, the width of the inclined walls being approximately equal to the half width of the U;
  • the height of the crests of the corrugated profile is small compared to the distance separating the top of the U from the stirring blade of the sieve, so that the variation of the depression produced by the blade, along the wall is insensitive.

Un exemple de réalisation est illustré au dessin annexé sur lequel:

  • la figure 1 représente une vue schématique d'un tamis selon l'invention;
  • la figure 2 représente une vue schématique en perspective d'une portion de tamis à fentes selon l'invention;
  • la figure 3 représente une vue schématique selon une variante de la figure 2 d'un tamis à fente, à profil en V.
  • la figure 4 représente une variante de la figure 3 d'un tamis à trous, à profil asymétrique;
  • la figure 5 représente une variante à profil ondulé à crêtes arrondies;
  • la figure 6 représente une vue de profil de la figure 2.
An exemplary embodiment is illustrated in the appended drawing in which:
  • Figure 1 shows a schematic view of a sieve according to the invention;
  • Figure 2 shows a schematic perspective view of a portion of slotted screens according to the invention;
  • Figure 3 shows a schematic view according to a variant of Figure 2 of a slotted sieve, V-shaped.
  • FIG. 4 shows a variant of FIG. 3 of a sieve with holes, with an asymmetrical profile;
  • FIG. 5 represents a variant with corrugated profile with rounded ridges;
  • FIG. 6 represents a profile view of FIG. 2.

En se reportant au dessin, on voit que le tamis est un cylindre réalisé dans une tôle de faible épaisseur, de préférence entre 1 et 3 millimètres. Il est formé d'éléments 1, pliés en forme générale de U, et juxtaposés de façon à former une paroi 2 tamisante.Referring to the drawing, it can be seen that the screen is a cylinder made from a sheet of thin thickness, preferably between 1 and 3 millimeters. It is formed of elements 1, folded in a general U shape, and juxtaposed so as to form a sieving wall 2.

De manière connue, le cylindre de la figure 1 peut être obtenu à partir d'éléments 1 de même longueur, juxtaposés, cintrés et soudés entre eux, ou bien à partir d'un élément 1 enroulé sur lui-même, en formant des spires adjacentes.In a known manner, the cylinder of FIG. 1 can be obtained from elements 1 of the same length, juxtaposed, curved and welded together, or else from an element 1 wound on itself, by forming turns adjacent.

Selon l'invention, le fond 3 du U n'est pas plat mais déformé longitudinalement de façon à présenter, d'une aile 4 à l'autre 5, au moins une crête 20 arrondie ou anguleuse. Dans le cas d'un profil à crêtes anguleuses, il présente alors entre les deux ailes 4,5 une succession d'au moins deux faces 6,7 adjacentes perforées inclinées par rapport au plan général 8 du tamis d'un angle 12,13 compris entre 0 et 90°. En coupe transversale le fond du U présente ainsi une forme en V au moins (figure 3) , ou en W (figure 2), etc.. symétrique ou non, l'inclinaison de deux faces 6, 7 opposées pouvant être de même valeur ou différentes comme illustré sur la figure 3.According to the invention, the bottom 3 of the U is not flat but deformed longitudinally so as to present, from one wing 4 to the other 5, at least one rounded or angular ridge 20. In the case of a profile with angular crests, it then has between the two wings 4,5 a succession of at least two adjacent faces 6,7 adjacent perforated inclined with respect to the general plane 8 of the screen at an angle 12,13 between 0 and 90 °. In cross section the bottom of the U thus has a shape at least in V (Figure 3), or in W (Figure 2), etc. symmetrical or not, the inclination of two opposite faces 6, 7 can be of the same value or different as shown in Figure 3.

Les perforations, trous 10 ou fentes 9, sont réalisées sur toutes les faces inclinées du fond du U; elles sont généralement réalisées avant déformation du fond du U, notamment lorsque les fentes sont associées à une nervure afin d'obtenir un profil du type à obstacle. Mais elles peuvent également être réalisées après formation du profil ondulé notamment lorsque l'on réalise de simples fentes.The perforations, holes 10 or slots 9, are made on all the inclined faces of the bottom of the U; they are generally made before deformation of the bottom of the U, in particular when the slots are associated with a rib in order to obtain a profile of the obstacle type. However, they can also be produced after the corrugated profile has been formed, in particular when simple slots are produced.

Cette disposition (du pliage du fond du U) a pour objet d'accroître la surface tamisante pour une même largeur de l'élément en U, c'est-à-dire pour un même encombrement du tamis.The purpose of this arrangement (of folding the bottom of the U) is to increase the sieving surface for the same width of the U-shaped element, that is to say for the same size of the sieve.

Cet accroissement de surface tamisante a pour conséquence qu'une même quantité de pâte, peut être plus rapidement traitée.This increase in sieving surface means that the same quantity of dough can be processed more quickly.

La disposition de la figure 2 montre un profil ondulé en forme de W à crêtes anguleuses. Cette disposition n'est pas limitative et l'invention porte également sur les profils en V, ou à crête arrondie, symétriques ou non (figures 3 à 6).The arrangement in Figure 2 shows a W-shaped wavy profile with angular ridges. This provision is not limiting and the invention also relates to the profiles in V, or with rounded crest, symmetrical or not (Figures 3 to 6).

Dans l'exemple de la figure 2, le fond du U est plié en forme de W symétrique. Les angles 14,14',14" formés entre les parois inclinées sont égaux, et de l'ordre de 60°. Cette disposition permet de doubler la surface 5 du fond du U et donc de doubler la surface du tamis.In the example in Figure 2, the bottom of the U is folded into a symmetrical W shape. The angles 14, 14 ′, 14 "formed between the inclined walls are equal, and of the order of 60 °. This arrangement makes it possible to double the surface 5 of the bottom of the U and therefore to double the surface of the sieve.

De tels tamis cylindriques sont, comme cela est bien connu, équipé d'une pale 16 de décolmatage, qui circule à grande vitesse devant les perforations; le décolmatage est réalisé par la dépression créée par la forme en aile de la pale.As is well known, such cylindrical sieves are equipped with an unclogging blade 16 which circulates at high speed in front of the perforations; unclogging is achieved by the depression created by the wing shape of the blade.

Selon l'invention l'aile se déplace dans une direction approximativement parallèle à l'axe longitudinal des éléments en U, perpendiculairement aux fentes 9 par exemple; le fond du U n'est donc pas à une distance constante de l'aile; le sommet 15 du ou des plis -sommet du V dans l'exemple de la figure 2- est plus proche de la pale que l'extrémité latérale 17 du pli. Afin d'éviter une trop grande variation de la dépression produite par la pale entre le sommet 15 et lesdites extrémités latérales 17, on prévoit de réaliser des plis dans lesquels la hauteur h entre le sommet du plis et la base du U (cf figure 2) est faible devant la direction D séparant le sommet 15 et la pale 16.According to the invention the wing moves in a direction approximately parallel to the longitudinal axis of the U-shaped elements, perpendicular to the slots 9 for example; the bottom of the U is therefore not at a constant distance from the wing; the top 15 of the top fold (s) of the V in the example of FIG. 2- is closer to the blade than the lateral end 17 of the fold. In order to avoid too much large variation in the depression produced by the blade between the top 15 and said lateral ends 17, provision is made for making folds in which the height h between the top of the folds and the base of the U (cf. FIG. 2) is small in front of the direction D separating the apex 15 and the blade 16.

Le présent exemple de réalisation décrit un tamis cylindrique centripète, mais l'invention n'est pas limitée à ce mode de fonctionnement et porte également sur les tamis centrifuges.The present embodiment describes a centripetal cylindrical sieve, but the invention is not limited to this operating mode and also relates to centrifugal sieves.

Claims (6)

Tamis pour épurateur ou classificateur de pâte à papier du type constitué par la juxtaposition d'éléments longitudinaux en tôle mince pliée à section générale symétrique en forme de U caractérisé en ce que le fond (3) perforé présente un profil ondulé à crête (20) arrondie ou anguleuse de façon que la surface de tamisage en contact avec la pâte soit augmentée très sensiblement.Screen for purifier or classifier of paper pulp of the type constituted by the juxtaposition of longitudinal elements in folded thin sheet metal with a generally symmetrical U-shaped section characterized in that the perforated bottom (3) has a corrugated crest profile (20) rounded or angled so that the sieving surface in contact with the dough is increased very significantly. Tamis pour épurateur ou classificateur de pâte à papier selon la revendication 1 caractérisé en ce que le fond (3) du U présente au moins deux parois (6,7) perforées inclinées successives opposées formant entre elles un angle (14) compris entre 45° et 90°.Screen for a pulp purifier or classifier according to claim 1 characterized in that the bottom (3) of the U has at least two successive inclined perforated walls (6,7) opposite forming between them an angle (14) of between 45 ° and 90 °. Tamis pour épurateur ou classificateur de pâte à papier selon la revendication 2 caractérisé en ce que le profil ondulé du fond du U présente une forme de W.Screen for a pulp purifier or classifier according to claim 2, characterized in that the corrugated profile of the bottom of the U has a shape of W. Tamis pour épurateur ou classificateur de pâte à papier selon la revendication 2 caractérisé en ce que le profil ondulé présente deux parois (6,7) inclinées en forme de V.Screen for a pulp purifier or classifier according to claim 2, characterized in that the corrugated profile has two walls (6,7) inclined in a V shape. Tamis pour épurateur ou classificateur de pâte à papier selon la revendication 3 caractérisé en ce que le profil en W est régulier, d'angles (14,14′,14˝) égaux, de l'ordre de 60°, la largeur des parois inclinées étant approximativement égale à la demi-largeur du U.Sieve for purifier or classifier of paper pulp according to claim 3 characterized in that the W-profile is regular, with angles (14,14 ′, 14˝) equal, of the order of 60 °, the width of the walls inclined being approximately equal to the half-width of the U. Tamis pour épurateur ou classificateur de pâte à papier selon la revendication 1 caractérisé en ce que la hauteur h au sommet du fond du U est faible devant la distance D séparant le sommet du U à la pale (16) d'agitation du tamis, de telle sorte que la variation de la dépression produite par la pale, le long de la paroi soit insensible.Screen for a pulp purifier or classifier according to Claim 1, characterized in that the height h at the top of the bottom of the U is small compared to the distance D separating the top of the U from the paddle (16) for agitating the screen, so that the variation of the depression produced by the blade, along the wall is insensitive.
EP91400922A 1990-04-18 1991-04-05 Screen for straining a classification of paper pulp Withdrawn EP0453348A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9004924A FR2661196B1 (en) 1990-04-18 1990-04-18 SCREEN FOR PURIFIER AND PULP CLASSIFIER.
FR9004924 1990-04-18

Publications (1)

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EP0453348A1 true EP0453348A1 (en) 1991-10-23

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EP91400922A Withdrawn EP0453348A1 (en) 1990-04-18 1991-04-05 Screen for straining a classification of paper pulp

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EP (1) EP0453348A1 (en)
JP (1) JPH04222287A (en)
FI (1) FI911865A (en)
FR (1) FR2661196B1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5417858A (en) * 1993-01-13 1995-05-23 Derrick Manufacturing Corporation Screen assembly for vibrating screening machine
US5417859A (en) * 1993-01-13 1995-05-23 Derrick Manufacturing Corporation Undulating screen for vibratory screening machine and method of fabrication thereof
US5921399A (en) * 1996-06-07 1999-07-13 Derrick Corporation Gumbo separator
US5958236A (en) * 1993-01-13 1999-09-28 Derrick Manufacturing Corporation Undulating screen for vibratory screening machine and method of fabrication thereof
US6000556A (en) * 1993-01-13 1999-12-14 Derrick Manufacturing Corporation Screen assembly for vibratory screening machine
EP1161308A1 (en) * 1998-12-23 2001-12-12 Thermo Black Clawson Inc. Papermaker's screen cylinder with helix screen element

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB519680A (en) * 1938-09-22 1940-04-03 James Walker Improvements in or relating to strainer plates and drums
GB2195911A (en) * 1986-10-08 1988-04-20 Ingersoll Rand Co Screening apparatus for pulp
WO1989012137A1 (en) * 1988-06-10 1989-12-14 Beloit Corporation Wave screen plate and manufacturing methods
EP0354846A1 (en) * 1988-08-12 1990-02-14 E &amp; M LAMORT Screen for the purification and classification of a pulp suspension

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB519680A (en) * 1938-09-22 1940-04-03 James Walker Improvements in or relating to strainer plates and drums
GB2195911A (en) * 1986-10-08 1988-04-20 Ingersoll Rand Co Screening apparatus for pulp
WO1989012137A1 (en) * 1988-06-10 1989-12-14 Beloit Corporation Wave screen plate and manufacturing methods
EP0354846A1 (en) * 1988-08-12 1990-02-14 E &amp; M LAMORT Screen for the purification and classification of a pulp suspension

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5876552A (en) * 1993-01-13 1999-03-02 Derrick Manufacturing Corporation Method of fabricating screen for vibratory screening machine
US5944993A (en) * 1993-01-13 1999-08-31 Derrick Manufacturing Corporation Screen assembly for vibrating screening machine
US5417793A (en) * 1993-01-13 1995-05-23 Derrick Manufacturing Corporation Undulating screen for vibratory screening machine and method of fabrication thereof
US5720881A (en) * 1993-01-13 1998-02-24 Derrick Manufacturing Corporation Screen assembly for vibrating screening machine
US5783077A (en) * 1993-01-13 1998-07-21 Derrick Manufacturing Corporation Undulating screen for vibratory screening machine
US5868929A (en) * 1993-01-13 1999-02-09 Derrick Manufacturing Corporation Screen assembly for vibrating screening machine
US5417859A (en) * 1993-01-13 1995-05-23 Derrick Manufacturing Corporation Undulating screen for vibratory screening machine and method of fabrication thereof
US6564947B2 (en) 1993-01-13 2003-05-20 Derrick Manufacturing Corporation Method of screening material utilizing a plurality of undulating screen assemblies
US5417858A (en) * 1993-01-13 1995-05-23 Derrick Manufacturing Corporation Screen assembly for vibrating screening machine
US5958236A (en) * 1993-01-13 1999-09-28 Derrick Manufacturing Corporation Undulating screen for vibratory screening machine and method of fabrication thereof
US6000556A (en) * 1993-01-13 1999-12-14 Derrick Manufacturing Corporation Screen assembly for vibratory screening machine
US6340089B1 (en) 1993-01-13 2002-01-22 Derrick Manufacturing Corporation Method of fabricating undulating screen for vibratory screening machine
US5921399A (en) * 1996-06-07 1999-07-13 Derrick Corporation Gumbo separator
EP1161308A1 (en) * 1998-12-23 2001-12-12 Thermo Black Clawson Inc. Papermaker's screen cylinder with helix screen element
EP1161308A4 (en) * 1998-12-23 2002-05-29 Thermo Black Clawson Inc Papermaker's screen cylinder with helix screen element

Also Published As

Publication number Publication date
FR2661196A1 (en) 1991-10-25
FI911865A (en) 1991-10-19
FR2661196B1 (en) 1992-07-17
JPH04222287A (en) 1992-08-12
FI911865A0 (en) 1991-04-17

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