Classifications

• • 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
  • B07B1/46—Constructional details of screens in general; Cleaning or heating of screens
  • B07B1/4609—Constructional details of screens in general; Cleaning or heating of screens constructional details of screening surfaces or meshes
  • B07B1/4618—Manufacturing of screening surfaces
• • 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
• • 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
  • B07B1/46—Constructional details of screens in general; Cleaning or heating of screens
  • B07B1/4609—Constructional details of screens in general; Cleaning or heating of screens constructional details of screening surfaces or meshes
  • B07B1/4681—Meshes of intersecting, non-woven, elements
• • 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
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/496—Multiperforated metal article making
  • Y10T29/49604—Filter
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49826—Assembling or joining
  • Y10T29/49908—Joining by deforming
  • Y10T29/49938—Radially expanding part in cavity, aperture, or hollow body

Definitions

• the invention relates to a sieve for fiber suspensions, namely a sieve of the type (so-called rod sieve basket) as it is the subject of WO 98/57723 from Hermann Finckh Maschinenfabrik GmbH & Co.
• Such a cylindrical or possibly also conical sieve with a rotationally symmetrical shape with respect to a sieve axis has a plurality of annular profile rod supports (also called support rings) which are located in planes running perpendicular to the sieve axis and at intervals from one another in the direction of the sieve axis, and which on their inner or outer circumference, and although usually on the inner circumference, are provided with a ring of cutouts which are arranged at intervals from one another in the circumferential direction and are edge-open towards this carrier circumference.
• annular profile rod supports also called support rings
• the cutouts of the ring-shaped profile bar supports lie one above the other in such a way that straight profile bars can be inserted and held in these cutouts, which extend transversely to the screen circumferential direction, are arranged at intervals from one another in the screen circumferential direction, and slot-like screen openings of the same width are located between them form, which are interrupted by the annular profile beam.
• all profile bars are of the same design (the distances between the support ring cutouts are then all the same size) and have a cross section of elongated shape, the longitudinal direction of the profile bar cross section being at least approximately radially oriented with respect to the screen axis; however, differently shaped profile bars could also be used.
• each profile bar With one end area of the profile bar cross section, each profile bar is inserted into a cutout of each of the profile bar supports, the shape of these cutouts corresponding to the shape of this cross section end area of the profile bars when viewed in the direction of the sieve axis and forming an undercut at a radial distance from the open cutout end, into which a projection of the profile bar cross-section engages in such a way that the profile bars are held in a form-fitting manner in the cutouts of the profile bar supports, both in the radial direction with respect to the screen axis and in the screen circumferential direction.
• the profiled bar supports provided with the cutouts can initially be in the form of straight bars or rails, which are bent into closed support rings after the insertion of the profiled bars into the cutouts, so that the profiled bars can be clamped in the support ring cutouts when the cutouts are located on the side of the profile rod carrier which later forms the inner circumference of the support rings.
• the straight or ring-shaped profile bar supports can also be plastically deformed, on the side of the profile bars which face away from the open ends of the cutouts, that as a result of a displacement of profile bar support material in the direction of the Profiled bars whose projections are pressed against the undercuts formed by the cutouts and thereby the profiled bars are fixed in the support rings - this measure can be used both from the outset in the form of annular profiled bar supports, and also in initially straight profiled bar supports, in the latter case before or after bending the profile beam to closed support rings.
• the invention was based on the object of a sieve of the type described in WO 98/57723 or in one of the publications mentioned in this document (EP-B-0 417 408 and EP-A-0 499 154) create, which is easier to assemble than these known sieves (strainer baskets) and which basically opens up the possibility of automated assembly of the profile bars in or on the profile bar supports.
• This object can be achieved according to the invention by a sieve according to claim 1 or by a manufacturing method according to claim 20.
• the invention thus relates to a sieve for fiber suspensions with a shape which is essentially rotationally symmetrical with respect to a sieve axis and a first and a second peripheral side, one of which forms an inlet and the other an outlet side of the sieve for the fiber suspension, with a series of straight profile bars, which extend transversely to the wire circumferential direction, are arranged at intervals from one another in the wire circumferential direction and form slot-shaped screen openings of the same width between them, and their cross sections each have an elongated shape with a first end area facing away from the second wire circumferential side and a second end area facing away from the first wire circumferential side have, as well as with several in the planes perpendicular to the sieve axis and in the direction of the sieve spaced from each other annular profile bar supports, each of which is facing away from the second side of the sieve first a series from the first side of the sieve circumference to cutouts with open edges, the shape of which - viewed in the
• the profile bars preferably have the same cross section (in shape and size) everywhere outside their recesses; In addition, embodiments are preferred in which all profile bars are of identical design.
• the profiled bars with their areas provided with the recesses are inserted into the cutouts of the profiled bar supports in the direction perpendicular to the longitudinal bar direction and then the profiled bar supports and profiled bars are displaced relative to one another in such a way that the profiled bar recesses outside the profiled bar supports and the second cross-sectional end areas of the profile bars are at least substantially free of play in the profile bar support cutouts.
• the invention makes it possible to insert the profiled bars transversely to their longitudinal direction at least almost without resistance into the cutouts of the profiled bar supports, whereupon the profiled bars and the profiled bar supports only have to be displaced relatively slightly in the longitudinal direction of the profiled bars in order to secure the profiled bars in the profiled bar support cutouts. Since both processes can be accomplished by relatively small movements of the profiled bars and / or the profiled bar supports without significant resistance being overcome, the invention also makes it possible to automate the assembly of a sieve according to the invention without fear that the relatively long ones and thin profile bars and / or the profile bar supports are bent.
• pressure sorters for fiber suspensions which have a rotationally symmetrical, basket-like (albeit open at the top and bottom) sieve and a rotor rotating around the sieve axis, which is either arranged inside the sieve basket or comprises the sieve basket on its outside (for example by having wing-like elements that pass the outside of the strainer) is that Sieve exposed to considerable pressure loads.
• the recesses to be provided on the profiled bars according to the invention practically do not impair the required resistance of the profiled bars to these pressure loads if the profiled bar recesses are in the vicinity of the profiled bar supports in the finished sieve; in preferred embodiments of the sieve according to the invention, all profiled rod recesses are arranged directly next to the profiled rod carriers, because then the weakening of the profiled rods through their recesses is meaningless with regard to the resistance of the sieve to the pressure loads described.
• the length of the profile bar recesses measured in the longitudinal direction of the profile bar be dimensioned to be the same size or slightly larger than the thickness of the profile bar support measured in the direction of the sieve axis.
• each profile bar recess (in a side view of the profile bar concerned) in the profile bar longitudinal direction passes without edges into the profile bar areas adjacent to the recess; in particular, a concave recess end region adjoins the actual profile rod recess (in the longitudinal direction of the profile rod) on both sides in order to ensure a smooth and steady transition of the recess into the adjacent, unattenuated regions of the profile rod.
• the length of the actual profile bar recess measured in the longitudinal direction of the profile bar (without the mentioned end end regions) is advantageously dimensioned to be the same size as the thickness of the profile bar supports measured in the direction of the sieve axis.
• the profile bars are used in the cutouts of straight profile bar supports in the manufacture of the sieve according to the invention and the latter are then bent into circular, self-contained support rings, in such a way that the cutouts of the profile bar supports are located on the inner circumference of the support rings, the clamping associated with the bending can be carried out the profile bars in the profile bar support cutouts are sufficient to secure the profile bars against longitudinal displacement relative to the profile bar supports.
• various measures could be taken to secure the profile bars against longitudinal displacements; for example, stop rings could be provided for the profile bars at the two axial ends of the sieve and these and the profile rod support by z. B.
• the securing of the profiled bars against longitudinal displacements by deformation of the profiled bar supports can be carried out not only on annular profiled bar supports, but also on straight profiled bar supports which already hold the profiled bars and which are subsequently formed into supporting rings.
• FIG. 1 is a perspective and largely schematic representation of the preferred embodiment of the sieve according to the invention (hereinafter called the strainer basket), which shows only a few profile bars.
• FIG. 2 is again a largely schematic plan view of the bar screen basket shown in FIG. 1, wherein only a few profile bars were also indicated;
• FIG. 3 shows a plan view of a relatively short section of a still straight profile bar support with three profile bars drawn in cross section, which have already been inserted into cutouts of the profile bar support, but are not yet fixed to the latter by a plastic deformation of the profile bar support;
• FIG. 4 shows a section through a profile bar designed according to the invention, the section plane running perpendicular to the longitudinal direction of the profile bar and through the longitudinal center of a profile bar recess according to the invention;
• FIG. 5 shows a view of the rear side of a profiled rod (view in the direction of arrow A in FIG. 4), the sectional plane of FIG. 4 being indicated by the line 4-4 in FIG. 5;
• Fig. 6 is a view of three profile bars and three
• Profile support seen in the direction of arrow B in Figure 1, Figure 6 shows only relatively short sections of the profile support and also does not represent the full length of the profile bars. 7 shows a section through a section bar and through short sections of three section bar supports according to line 7-7 in FIG. 3;
• FIG. 8 shows a representation corresponding to FIG. 3, but after the plastic deformation according to the invention of the profiled bar carrier shown for the purpose of displacing profiled bar carrier material in the direction of the profiled bars;
• Fig. 9 is a section along the line 9-9 in Fig. 8, and
• Fig. 10 is a representation corresponding to Fig. 9, but including two rolling tools for plastic deformation of the profile bar support according to the invention.
• Figures 1 and 2 show that the sieve designed as a bar screen basket according to the invention consists of several profile bar supports in the form of support rings 10 and a series of profile bars 12, the latter running parallel to a screen axis 14 and the support rings 10 are in planes perpendicular to the screen axis and are arranged at equal distances from one another.
• the profile bars 12 are designed and arranged such that the inlet side 16 of the sieve for the fiber suspension to be sorted lies on the inner periphery of the sieve basket and the outlet side 18 for the fiber suspension let through by the sieve basket lies on the outer periphery of the sieve basket.
• Each of the particularly identical support rings 10 has a cross section in the form of a flat rectangle and has an upper flat side 20, a lower flat side 22, an outer edge 24 and an inner edge 26.
• 3 shows a short section of a still straight profile bar carrier 10 ', which is later to be formed into a closed support ring 10 by bending and, for example, welding its ends together.
• the first edge of the profile rod carrier 10 'corresponding to the inner edge 26 of the support ring 10 was designated 26'
• the second edge of the profile rod carrier 10 'corresponding to the outer edge 24 of the support ring 10 was designated 24'
• the upper flat side of the profile rod carrier 10 visible in FIG. 3 ' was designated with 20'.
• the profile bar support 10 ' has a cutout 34 in which a profile bar 12 is held in a positive manner in the longitudinal direction of the profile bar support 10' and in the direction perpendicular to this longitudinal direction and lying in the plane of the drawing in FIG. 3, even if with one relatively minor game recognizable in Fig. 3.
• all profiled bars 12 should have the same shape and the same dimensions, and the same also applies to the support rings 10 or to the still straight profiled bar supports 10 ', but in particular to their cutouts 34. Outside the inventive profiled bar recesses to be discussed The profile bars have the same cross-section as shown in FIG.
• the shape of which is preferably approximately mushroom-shaped with a mushroom head forming a first cross-sectional end region 12A and an approximately club-shaped mushroom-base forming a second cross-sectional end region 12B
• the shape of the second cross-sectional end region 12B corresponding to the shape of the cutout 34 corresponds, apart from the play of the profiled bars 12 in the cutouts 34 of the still straight profiled bar supports 10 ', which can be seen in FIG. 3.
• each of the cutouts 34 is designed according to the invention in such a way that the cutout 34 has a constriction 34A, between which and the end of the cutout 34 facing the second edge 24' of the profiled bar support 10 'forms an undercut 34B, in the area of which the edge of the section 34 has an approximately straight flank 34C, which is designated by a reference numeral 40 in FIG. 3, perpendicular to the plane of the drawing
• Fig. 3 extending plane forms an acute angle ⁇ , which opens in the direction of the second edge 24 'of the profile bar support 10'.
• the plane 40 forms a diameter plane of the bar screen basket.
• the second cross-sectional end region 12B of the profile bars 12 forms a projection 12C which engages in the undercut 34B of the associated cutout 34, so that even before the profile bar support 10 'is deformed, the profile bars 12 do not protrude upward from the cutouts 34 (according to FIG. 3) let it pull out.
• each profile bar 12 lies with that part of its outer circumference which delimits its first cross-sectional end region 12A against the first edge 26 'of the profile bar support 10', so that the profile bars 12 are positioned relative to the profile bar supports 10 '. also not (see Fig. 3) move down.
• each profile bar 12 has on its one side, on one side of its second cross-sectional end region 12B, a plurality of trough-shaped recesses 50, which are arranged in the longitudinal direction of the profile at intervals from one another which are measured in the direction of the screen axis 14 Distances of the support rings 10 correspond to each other.
• the recesses 50 are essentially 5 are designed concave troughs or grooves, the longitudinal axis of which runs perpendicular to the plane of the drawing in FIG.
• the recesses 50 are advantageously designed in such a way that the second cross-sectional end regions 12B of the profiled bars 12 according to FIG. 3 can be inserted into the cutouts 34 from above without the profiled bars and / or the profiled bar supports 10 'or the support rings 10 being worth mentioning be deformed elastically or even plastically; for this purpose, the recesses 50 are designed so that they have their greatest depth over such a length, measured in the longitudinal direction of the profile bar, which is equal to that in the direction of the screen Axis 14 measured thickness of the support rings 10.
• the profile bars 12 are first inserted into the cutouts 34 (according to FIG. 3 from above), so that the second cross-sectional end areas 12B of the profile bars in the Cutouts 34 come to rest, whereupon the profile bars are displaced relative to the profile bar supports or the support rings in the longitudinal direction of the profile bar such that the recesses 50 lie directly next to the profile bar supports or support rings, as is shown in FIGS. 6 and 7 - the unattenuated second cross-sectional end areas 12B the profile bars 12 are then held in a form-fitting manner in the cutouts 34, apart from a slight play, which may initially still be present, indicated in FIG. 3, between the profile bars and the profile bar carriers or support rings.
• FIGS. 3 and 6 also show the slit-shaped screen openings 56, which then lie between the mushroom-like first cross-sectional end regions 12A of the profile bars 12, extend in the longitudinal direction of the profile bars 12 or in the direction of the screen axis 14, through the profile bar Carrier 10 'or the support rings 10 are interrupted, all run parallel to each other and all have the same width (measured in the longitudinal direction of the profile bar support 10' or in the circumferential direction of the support rings 10).
• the narrow gap indicated in FIG. 3 between the flank 34C of the cutouts 34 and the projection 12C of the profiled bars 12 can be closed and eliminated by reshaping the initially straight profiled bar supports 10 'into annular supporting rings 10, in such a way that that the profile bars 12 lie on the inner circumference of the support rings 10.
• the profile bars 12 can also be clamped in the cutouts 34 as described and illustrated in WO 98/57723 and as is to be the case with the preferred embodiment of the screen according to the invention. This procedure will now be described with reference to FIGS. 8 to 10.
• An upper pressure roller 60 and, from below, a lower pressure roller 62 are pressed against the profile bar support 10 'shown in FIGS. 8 to 10 (optionally against a support ring 10) (see FIG. 10), which is around one another and to the flat sides of the profile bar support 10 'parallel axes 60' or 62 'are freely rotatable; these axes also run perpendicular to the longitudinal direction of the profile bar support 10 'or radially to the screen axis 14.
• the pressure rollers 60 and 62 are under control or regulation of the pressure with which they are shown in FIG.
• the angle ⁇ which can be seen in FIG. 3 is expediently dimensioned such that, after the deformation according to the invention, there is self-locking between the flanks 34C and the flanks of the profiled bar projections 12C pressed against it.
• FIG. 8 represents a section from FIG. 2 and does not show a profiled beam 10 ', but the support ring 10, it can be seen that the profiled bars 12 even after the profiled beam 10' has been formed into closed support rings 10 between them form slot-shaped sieve openings 56, which run parallel to the sieve axis 14 and are interrupted by the support rings 10.
• the sieve inlet side 16 communicates with the sieve outlet side 18 via these sieve openings 56.
• the profile bars 12 on the screen inlet side 16 are inclined at the end Flanks 82 and 84 and provided with rear flanks 86 and 88; the latter form stops with which the profile bars 12 bear against the first edge 26 of the support rings 10 (see FIG. 8).
• the inclined flanks 82 and 84 provided on the end face form acute angles with the plane 40 indicated in FIG. 3, which angles can be the same size or different.
• the first cross-sectional end regions 12A of the profiled bars 12 generate microturbulences in the fiber suspension to be sorted, in particular with their inclined flanks 82 and 84 Microturbulences counteract the formation of an appreciable nonwoven fabric on the screen inlet side 16 and blockage of the screen openings 56.
• the profile bars 12 are preferably made of drawn metal profile bars or extruded plastic profiles, in which the recesses 50 z. B. be produced by milling or grinding.
• the profile rod supports or support rings are preferably made of metal, although plastic parts are also possible in principle.
• a typical strainer basket according to the invention has a length of 40 to 200 cm in the direction of the sieve axis 14 as well as profile bars, the cross section of which is a length of approx. 6 to 8 mm and has a maximum width of approx. 2.5 to 4 mm, and the slit-shaped sieve openings delimited by the profile bars have a clear slit width of approx. 0.1 mm to approx. 1 mm, in particular of approx. 1 to approx. 0.2 mm with a tolerance of the slot width of preferably only 0.01 mm.
• the thickness of the support rings 10 measured in the direction of the sieve axis 14 is of the order of 4 to 5 mm. From these dimensional relationships and tolerances, it becomes clear how problematic it would be to insert the profile bars in the longitudinal direction of the profile bars into the cutouts of the support rings or profile bar supports without the thin profile bars being bent.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Paper (AREA)
• Combined Means For Separation Of Solids (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

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• 2000
  • 2000-02-19 CA CA002403127A patent/CA2403127A1/fr not_active Abandoned
  • 2000-02-19 ES ES00906359T patent/ES2226787T3/es not_active Expired - Lifetime
  • 2000-02-19 DE DE50008550T patent/DE50008550D1/de not_active Expired - Lifetime
  • 2000-02-19 WO PCT/EP2000/001385 patent/WO2001061104A1/fr active IP Right Grant
  • 2000-02-19 EP EP00906359A patent/EP1297218B1/fr not_active Expired - Lifetime
  • 2000-02-19 AT AT00906359T patent/ATE281554T1/de not_active IP Right Cessation
• 2002
  • 2002-08-15 US US10/219,209 patent/US6789681B2/en not_active Expired - Fee Related

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