EP0119345B1 - Sortiervorrichtung für Papierfaserstoff - Google Patents

Sortiervorrichtung für Papierfaserstoff Download PDF

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Publication number
EP0119345B1
EP0119345B1 EP83306207A EP83306207A EP0119345B1 EP 0119345 B1 EP0119345 B1 EP 0119345B1 EP 83306207 A EP83306207 A EP 83306207A EP 83306207 A EP83306207 A EP 83306207A EP 0119345 B1 EP0119345 B1 EP 0119345B1
Authority
EP
European Patent Office
Prior art keywords
screen member
shell
perforations
screening
inch
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.)
Expired
Application number
EP83306207A
Other languages
English (en)
French (fr)
Other versions
EP0119345A1 (de
Inventor
David E. Chupka
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.)
Black Clawson Co
Original Assignee
Black Clawson 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 Black Clawson Co filed Critical Black Clawson Co
Publication of EP0119345A1 publication Critical patent/EP0119345A1/de
Application granted granted Critical
Publication of EP0119345B1 publication Critical patent/EP0119345B1/de
Expired legal-status Critical Current

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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
    • D21D5/16—Cylinders and plates for screens

Definitions

  • Paper mills have for many years made extensive use, for the cleaning of paper making stock, of screening apparatus embodying a cylindrical perforated screening member defining supply and accepts chambers on the opposite sides thereof in a closed housing, and including a rotor member which operates in one of the chambers to keep the screening perforations open and free from solid material tending to cling to the screening surface.
  • a cylindrical perforated screening member defining supply and accepts chambers on the opposite sides thereof in a closed housing, and including a rotor member which operates in one of the chambers to keep the screening perforations open and free from solid material tending to cling to the screening surface.
  • the stock or furnish is delivered to the supply chamber adjacent one end of the screening cylinder, and the material rejected by the screening cylinder is collected and discharged from the opposite end of the supply chamber.
  • Both of the Lamort and Chupka-Seifert patents also show, in addition to slotted cylinders, a plurality of shoulders or small bars running generally axially of the screen cylinder in circumferentially spaced relation around the inlet side of the cylinder.
  • the rotor arrangement is described by Lamort as preventing clogging of the screening slots by fiber, albeit in an undescribed manner.
  • the purpose of the bars is described as to generate a field of high intensity, fine scale turbulence in the stock adjacent the inlet side of the screen cylinder and thereby to effect screening of paper fiber stock with minimum fractionation thereof on the basis of fiber length.
  • Chupka-Seiffert patent discloses the application of a similar multi-bar arrangement to a screen cylinder having circumferentially extending slots of a substantially greater range of widths, i.e.
  • EP-A-0046687 discloses that when a pressure screen is equipped with a screening cylinder provided with screening holes of circular or vertically slotted shape and multiple bars spaced circumferentially about the inlet side thereof, dramatic improvements of the capabilities of the screen resulted. More particularly, when compared with standard screens having round holes in the screening cylinder in accordance with the above noted Seiffert patents, a screen having such an arrangement of circumferentially spaced bars on its inlet side will produce a higher tonnage of accepted fiber per day while screening stock of higher consistency through smaller holes, and also will draw less power per unit of accepted fiber.
  • Chupka-Seifert '841 patent discloses screen cylinders provided with circumferentially extending slots of a width range of 0.025 to 0.203 mm (.001-.008 inch), it is extremely difficult to obtain such narrow slots of uniform width even when the cylinder is formed of spirally wound wire as disclosed in that patent. Further, since slots parallel with the axis of a screen cylinder are most conveniently produced by means of a saw, the minimum thickness of saws suitable for such use in steel or other metal adequately stiff for use as a screen cylinder establishes the practical minimum of such slots.
  • the minimum width which can be maintained in a circumferentially slotted screen produced from spirally wound wire is not less than 0.256 mm (.0101 inch), and the smallest width obtainable with a saw in a screen cylinder having slots parallel with its axis is of the order of 0.152 mm (.006 inch).
  • the practical minimum diameter of a cylindrical hole drilled in typical screen cylinder steel plate is approximately 1.27 mm (.050 inch), while even in stainless steel as thin as 1.59 mm ( 1 1, 6 inch), it is not possible to punch holes less than approximately 0.94 mm (.037 inch) in diameter.
  • the present invention has solved this problem by an entirely different approach to its ultimate objective of obtaining uniformly sized screening slots and circular holes of the smallest practical width or diameter.
  • This approach involves, as a first step, producing a base shell having the desired slot arrangement or circular holes of as small a minimum dimension as can be uniformly maintained - which has been found to be approximately 0.152 mm (.006 inch) width for slots parallel with the axis, 0.254 to 0.356 mm (.010-.014 inch) for circumferentially extending slots, and a diameter of 1.27 mm (.050 inch) for circular holes.
  • a screening member according to the preamble of claim 1, comprising the resulting cylindrical shell having multiple perforations therethrough of a predetermined minimum cross sectional dimension is provided with a coating which forms a lining for the wall of each of the perforations which reduces said cross sectional dimension of each perforation to a predetermined value.
  • the coating is of predetermined uniform thickness and covers the inner and outer surfaces of the shell as well as forming a lining for the wall of each of the perforations.
  • Such coatings have the desired adherence to steel and controlled uniform thickness to provide screening cylinders with holes of a uniform minimum diameter of 0.025 mm (.001 inch) and slots of a uniform minimum width of 0.025 mm (.001 inch) when the circular holes were initially as large as 1.27 mm (.050 inch) in diameter and the slots were axially extending sawed slots of a width of 0.152 mm (.006 inch) or circumferentially extending slots of a minimum width as great as 0.356 mm (.014 inch).
  • the screening apparatus shown in Fig. 1 is constructed generally in accordance with Seifert U.S. patent No. 4,105,543, with certain exceptions in accordance with the invention. It comprises a main housing 10 on a base 11, and in the upper end of the housing is an inlet chamber 12 having a tangential inlet port 13 to which the furnish is fed under pressure as is customary with such screening apparatus.
  • a cylindrical screening member 15 provided with multiple substantially circular holes 16 divides the interior of the housing below chamber 12 into a center supply chamber 17 and an accepts chamber 18 having an outlet port 19.
  • the bottom wall 20 of the supply chamber includes a trough 21 leading to a discharge port 22 provided with a control valve assembly 23 which can be preset to provide a desired continual bleed of reject-rich stock. Heavy particles which settle into the trough 21 drop therefrom to the heavy trash collection box 24 by way of manually controlled valve 25 for intermittent removal.
  • a rotor 30 is supported on a drive shaft 31 in the center of the supply chamber 17 and is driven through suitable gearing or belts by a motor 33 also mounted on the base 11. Vanes or bars 35 are mounted on the rotor 30 by support rods 36, and adjustable connections 37 between the inner ends of rods 36 and rotor 30 provide for positioning the vanes 35 in properly spaced relation with the inner surface of screening member 15.
  • the vanes 35 extend the full length of the screening surface of screen member 15, and they are preferably helically curved and so arranged that the upper end of each vane is spaced forwardly of the lower end in the direction of rotation of the rotor. In fig. 1 two vanes 35 are shown, but other numbers can be used, and in general a greater number, e.g., four, may make possible improved operation at higher consistencies.
  • the screening cylinder 15 is provided along its inner (inlet) side with a plurality of bars 40, shown as of essentially square section, which extend generally axially thereof in circumferentially spaced relation, and cooperate with the surface portions of the member 15 therebetween to form a series of shallow pockets 42.
  • the radial dimension between the vanes 35 and the radially inner surfaces of the bars 40 should be relatively small, preferably of the order of 1.59 mm ( 1 1, 6 inch), but it may vary within a range of approximately 0.254 to 0.953 mm (0.010-0.375 inch).
  • the present invention is particularly concerned with the production of screening holes 16 of uniformly much smaller size than have previously been possible, e.g. cylindrical holes as small as 0.254 mm (.010 inch) in diameter.
  • the technique of the invention is to drill holes 16 in the steel plate shell 15 by means of as small a drill as can be used successfully in steel plate as thick as 7.94 mm (5/,fi inch). Practical experience has established that the minimum such diameter is approximately 1.27 mm (0.050 inch), with the outlet end of each hole preferably relieved by countersinking as shown.
  • the drilled plate has been provided with the desired bars 40, and has been rolled and welded into the proper cylindrical form, it is subjected to an electroless nickel coating process, during which a coating 44 is deposited in a uniform thickness over the entire surface of the cylindrical shell, thereby also forming a lining for each hole 16 which will correspondingly reduce the diameter of the hole.
  • the thickness of the coating 44 may be controlled to 0.318 mm (.0125 inch) to provide each hole 16 with a final minimum diameter of 0.635 mm (.025 inch).
  • each of the pockets 42 will have a substantial circulatory momentum and will therefore tend to reverse its direction of flow within the pocket into which it is diverted. Since the action of the vanes is also to create alternating pressure waves through the holes 16, which are radially outward while each vane approaches each pocket and radially inward as each vane passes the pocket, the result of the combination of forces is the development of a high degree of local turbulence in each pocket.
  • the interior of the supply chamber is under continuous pressure from the pump by which stock is supplied to the screen, and there is therefore a force continuously urging stock to discharge through the holes 16 into the accepts chamber 18.
  • the turbulence within the pockets has the effect of keeping the fibers within each pocket in a continuous condition of changing random orientation and thereby promotes their passage through the holes 16, particularly the long fibers which otherwise tend to become aligned tangentially of the cylinder and thereby to flow past the holes 16 instead of through them.
  • the screen of the invention could handle almost one-half the feed rate of the screen with perforations four times larger in flow area at a consistency of more than 3.50 percent, and its acceptance/reject ratio was still approximately 70 percent as compared with approximately 83 percent for the larger perforations which necessarily accepted many contaminant particles too large for acceptance by the 0.635 mm (.025 inch) holes in the screen of the invention.
  • the resulting greatly increased cleanliness of the accepted stock would more than compensate for the comparatively small decrease in capacity.
  • Figs. 4-5 illustrate the application of the invention to a screen cylinder which has a pattern of axially arranged slots like that shown in Seifert 3,849,302.
  • the cylinder 50 is formed like the cylinder 15 except that it is provided with multiple screening slots 51 which extend vertically, i.e. axially of the cylinder, in axially spaced circumferentially extending rows.
  • This screening cylinder also has multiple bars 52 welded along its inlet side, which may be of the same dimensions described in connection with Figs. 1-2, but which are straight and extend axially of the cylinder.
  • the screening slots 51 are initially formed as saw cuts using a circular saw as thin as is practical for use in steel plate as thick as 7.94 mm (% 6 inch). Practical experience has established that it is possible to maintain a consistent slot width of 0.152 mm (.006 inch) by such sawing method, and the cylinder is then subjected to electroless nickel coating until the coating 55 has reached a thickness providing the desired minimum width for the slots 51, e.g. a coating 0.064 mm (.0025 inch) in thickness to provide a slot width of 0.025 mm (.001 inch).
  • Figs. 4-7 illustrate the application of the invention to a screening cylinder 60 constructed as disclosed in the above-identified Chupka-Seifert patent and application from a series of rings 61 of wire of generally triangular section arranged in spaced relation axially of the cylinder to define screening slots 62 therebetween.
  • a screening cylinder can be made either by laying up a series of rings 62 in a suitable jig, or by winding the wire in a spiral pattern. With either of those production techniques, however, it has been found difficult to maintain uniform slot widths of less than about 0.254 mm (.010 inch), and it is easier if they are somewhat larger.
  • either of the above techniques for forming the cylinder 60 may be employed to produce a screening cylinder having circumferentially extending slots of as small a width as can be practically maintained uniform, e.g. from 0.254 to 0.356 mm (.010 to .014 inch).
  • the completed cylinder, with the bars 63 welded in place, is then subjected to electroless nickel coating until a coating 65 of the desired uniform thickness has been produced.
  • the coating should be 0.152 mm (.006 inch) thick.
  • the invention is not limited in principle to use with electroless nickel coatings, but preferred results have been obtained thereby because of the particular properties of electroless nickel coatings, including strong adhesion to steel, easily controlled uniformity of thickness and smoothness, and fidelity to the detail of the coated material. Because of this latter characteristic, such a coating will accurately reproduce the hole or slot which it lines, to provide the desired final minimum dimension for the inlet ends of the screening perforations.
  • the principle of the invention is applicable to materials other than steel as the base shell of the screening cylinder, and to other coating materials.
  • the screening cylinder could be of any material other than nickel which is appropriately stiff and strong, as well as certain plastics, e.g. polypropylene.
  • the coating may be of any material which will adhere to the base shell with the desired strength and will reproduce in adequately accurate detail the outlines of the coated shell. The choice of both the material of the base shell and the material with which is coated is accordingly open to those skilled in the selection and use of such materials, guided by the principle of the invention as set forth above and in the claims.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Paper (AREA)
  • Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)

Claims (8)

1. Sortierteil für den Einbau im Gehäuse (10) einer Sortiervorrichtung für Papierfaserstoff zur Abtrennung des Gehäuseinneren in eine Zuführkammer und eine Gutstoffkammer, wobei das Sortierteil eine zylindrische Basisschale (15, 50, 60) mit Vielfachperforationen (16, 51, 62) eines vorbestimmten minimalen Querschnittsmaßes durch die Schale hindurch aufweist, dadurch gekennzeichnet, daß eine Schicht (44, 55, 65) eine Verkleidung für die Wand jeder der Perforationen bildet, welche das Querschnittsmaß jeder Perforation auf einen vorbestimmten Wert verringert.
2. Sortierteil nach Anspruch 1, dadurch gekennzeichnet, daß die Schicht (44, 55, 65) eine bestimmte gleichmäßige Dicke hat und die innere und äußere Oberfläche der Schale abdeckt sowie eine Verkleidung für die Wand jeder Perforation bildet.
3. Sortierteil nach Anspruch 1 oder 2, wobei die Schale (15, 50, 60) aus einem Metall zusammengesetzt ist und die Schicht aus stromlos aufgebrachtem Nickel zusammengesetzt ist.
4. Sortierteil nach Anspruch 1, 2 oder 3, wobei die Perforationen (16) in radialem Schnitt kreisförmig sind und das vorbestimmte Maß der Minimaldurchmesser jeder Perforation ist.
5. Sortierteil nach Anspruch 1, oder 3, wobei die Perforationen parallele Schlitze (51, 62) sind und das vorbestimmte Maß die minimale Breite jedes Schlitzes ist.
6. Sortierteil nach Anspruch 5, wobei die Schlitze (51) sich zur Achse der Schale parallel erstrecken.
7. Sortierteil nach Anspruch 6, wobei sich die Schlitze (62) im wesentlichen über den Umfang der Schale erstrekken.
8. Sortierteil nach einem vorhergehenden Anspruch, wobei an der Einlaßseite der Basisschale eine Mehrzahl von Stangen (40, 63) befestigt sind, die sich im allgemeinen axial zur Schale in am Umfang relativ dichten und gleichmäßigen Abständen erstrecken, um mit der benachbarten Oberfläche der Schale eine Reihe von Taschen (42) zu bilden, wobei das Maß jeder Stange (40, 63), radial zur Schale gemessen, ausreicht, um eine Unterbrechung der Zirkulation des Stoffes unmittelbar neben der Einlaßseite des Sortierteils zu bewirken, und die Schicht die Stangen bedeckt.
EP83306207A 1983-01-21 1983-10-13 Sortiervorrichtung für Papierfaserstoff Expired EP0119345B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US45986783A 1983-01-21 1983-01-21
US459867 1983-01-21

Publications (2)

Publication Number Publication Date
EP0119345A1 EP0119345A1 (de) 1984-09-26
EP0119345B1 true EP0119345B1 (de) 1987-01-07

Family

ID=23826448

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83306207A Expired EP0119345B1 (de) 1983-01-21 1983-10-13 Sortiervorrichtung für Papierfaserstoff

Country Status (6)

Country Link
EP (1) EP0119345B1 (de)
JP (1) JPS59137593A (de)
BR (1) BR8306273A (de)
DE (1) DE3368957D1 (de)
ES (1) ES284538Y (de)
FI (1) FI840214A (de)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH086274B2 (ja) * 1986-11-28 1996-01-24 石川島播磨重工業株式会社 紙料のスクリ−ン
JPH0238496U (de) * 1988-09-02 1990-03-14
JPH03249296A (ja) * 1990-02-23 1991-11-07 Honshu Paper Co Ltd 耐摩耗性スクリーンプレート
DE19620051A1 (de) * 1996-05-18 1997-11-20 Voith Sulzer Stoffaufbereitung Vorrichtung zum Sortieren von faserstoffhaltiger Suspension
JP4577065B2 (ja) * 2005-03-31 2010-11-10 王子製紙株式会社 スクリーン装置およびこれを用いた再生パルプの製造方法
DE102012205506A1 (de) * 2012-04-04 2013-10-10 Voith Patent Gmbh Sieb
CN110258164B (zh) * 2019-07-17 2021-04-20 山鹰国际控股股份公司 一种除渣新工艺

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2347716A (en) * 1939-07-19 1944-05-02 Black Clawson Co Apparatus for screening paper stock
US2658840A (en) * 1950-07-18 1953-11-10 Agrashell Inc Process for the manufacture of laminates
US2835173A (en) * 1955-03-03 1958-05-20 Black Clawson Co Paper machinery
DE1905832U (de) * 1964-09-16 1964-12-03 Hermann Finckh G M B H Sichter fuer papierstoff-suspensionen.
FR1539846A (fr) * 1967-08-02 1968-09-20 E Et M Lamort Fils Ets Perfectionnement aux épurateurs notamment pour les pâtes à papier
US3849302A (en) * 1972-09-12 1974-11-19 Black Clawson Co Method and apparatus for screening paper fiber stock
US4105543A (en) * 1974-08-09 1978-08-08 The Black Clawson Company Method for screening paper fiber stock
US4155841A (en) * 1977-03-22 1979-05-22 The Black Clawson Company High turbulence screen
JPS5637393A (en) * 1979-08-30 1981-04-11 Mitsubishi Heavy Ind Ltd Screen apparatus for paper stock
CA1180686A (en) * 1980-08-25 1985-01-08 Black Clawson Company (The) Paper making stock screening apparatus incorporating circular apertured cylindrical pressure screen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ENCYCLOPEDIA OF ENGINEERING MATERIALS AND PROCESSES, Reinhold publishing corporation, 1963, Seiten 210-213 *

Also Published As

Publication number Publication date
JPS59137593A (ja) 1984-08-07
FI840214A0 (fi) 1984-01-19
ES284538U (es) 1985-06-01
EP0119345A1 (de) 1984-09-26
DE3368957D1 (en) 1987-02-12
BR8306273A (pt) 1984-09-18
FI840214A (fi) 1984-07-22
ES284538Y (es) 1986-02-16

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