JP2003506578A - Papermaking screen cylinder with helical screen element - Google Patents

Abstract

Abstract: A papermaking screen cylinder (10) is formed as a helical strip (15) of sheet material joined along a peripheral edge to form a locking seam (18). 11). The strip (15) may be perforated with an opening, such as a hole, or may have an opening or hole formed after being spirally wound. The strip (15) preferably undulates in a widthwise cross-sectional direction with ridges (21, 22) extending parallel to the end of the strip to increase the beam strength of the strip. The end ring may be made of stainless steel, or an embedded anchor made of a polymeric or composite material (36) bonded onto the end of the cylindrical screen body and extending through the screen body and into the material of the ring. May be held by

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a papermaking screen cylinder having a spiral screen element.

[0002]

[Prior Art and Problems to be Solved by the Invention]

Paper pulp and paper mills have extensively used pressure sorters for many years to wash papermaking ingredients. The stock suspension for papermaking may contain new fibers and / or large amounts of recycled fiber material. Commonly used sorters typically use a cylindrical perforated sorter in a closed pressure housing. The sorting member divides the internal chamber of the pressure housing into a respective inlet chamber and receiving chamber on each side of the perforated screen. The inlet chamber may be considered the high pressure side of the screen and the receiving chamber may be considered the low pressure side of the screen.

In such a pressure sorting device, normally, one side of the sorting screen is usually on the high pressure side so that the sorting hole is not blocked or clogged with the solid material and is kept open. It uses a rotor that operates to move vanes, foils, or other impulse members along at high speed. Usually, the stock suspension or so-called "furnish" is conveyed to the inlet chamber adjacent one end of the sorting cylinder, and the material rejected by the sorting cylinder is collected and discharged at the other end.

Prior application patents disclosing such a device including a sorting cylinder and an impact foil include, for example, US Pat.
017,387 and Lehman US Pat. No. 4, issued June 30, 1981.
, 276,159, and another example is Lehman's specification, column 1
There are references cited on lines 8-23.

In a pressure sorting device of the type described above, the rotor as described above preferably has impact members or vanes of blade cross section, which impact members or vanes are arranged in a closest packing, but cylindrical It moves out of contact with the face of the sorting member, preferably the internal inlet high pressure face. These vanes generate alternating positive and negative pressure waves that are effective in preventing holes from being blocked during drilling of the sorting cylinder and allowing the pressure sorting device to operate at high volumes. To do. In this normal sorting process, a high pressure is applied to the sorting member and it is reinforced by a rigid cylinder made of at least 3/16 inch stainless steel by the end rings and often surrounding the ring intermediate the end rings. It has been found desirable to make such a sorting screen from a rigid cylinder.

The holes in the sorting cylinder may be either slots or holes. For example,
Sorting holes are disclosed in Martindale U.S. Pat. No. 2,835,173 and processed slots are disclosed in Lehmann U.S. Pat. No. 4,276,159.
Laser cutting has also been used to form either slots or holes in the sorting material, as disclosed in Chapka US Pat. No. 4,795,360.

Material and manufacturing costs are high due to the need to use sorting screens having wall thicknesses on the order of 3/16 inches or more. For example, a 24 inch or 24 inch or larger diameter sorting screen may weigh up to 150 pounds or more. The screening surface is provided with openings in the form of closely packed holes or slots to provide a screen with the desired openings, optionally including precision machining and / or laser cutting, including electrical discharge machining. It may be cut by a combination. The thickness of the sorting wall requires time consuming and expensive slotting and cutting techniques in addition to the labor costs of preparing such a sorting cylinder. Therefore, there is a need for a lightweight, inexpensive sorting cylinder member for a closed pressure sorting apparatus of a paper manufacturer for sorting a slurry or suspension of paper raw materials.

[0008]

[Means for Solving the Problems]

The present invention is an improved lightweight and inexpensive cylindrical screen member for use in a pressure type sorting apparatus for sorting papermaking raw materials, wherein the sorting section is a spiral wound endless strip or sheet material. It includes a generally cylindrical tubular portion of strips joined along their ends. The strip sheet material is undulating in the cross-sectional direction, the axis of the undulation preferably extending substantially parallel to the longitudinal direction of the strip to provide radial stiffness. The wall thickness of the undulation strip, as outlined above, is substantially thinner than required by conventional screen cylinders,
For example, about 0.60 inches or less in thickness. Further, the openings or perforations in the screen therethrough may be used to perforate the strip material after the same has been formed for the cylinder, or by cutting, drilling, or laser cutting the screen wall. Is performed by drilling. Therefore, the screen cylinder of the present invention need not be limited to punched holes or holes, and sorting slots may be formed.

The use of spiral wound strip material, such as stainless steel sheet material, provides surprising advantages. If the strip material is undulating along its length, the strength or radial stiffness of the finished cylindrical section will increase substantially. Strength is also increased by the interlocking seams formed at each peripheral edge of the strip material.
The locking seams are preferably interlocked at their ends, folded and pressed flat. The seam may be resistance welded during the forming process. The seam may be welded with or without flux.

The seam may be rolled and bonded to the cylinder and may be located “inside” or “outside” the cylinder. During the manufacture of the cylinder according to the invention, it is preferred to form the seam so that the major part of the seam thickness extends inwardly with respect to the inlet face.
In this manner, the seams tend to form helical slide grooves that increase the flow of rejects along the screen surface to the rejects outlet. The undulation axis extending parallel to the seam also induces a flow of feed slurry and rejects to the screen outlet. These effects depend on the choice of the direction of the helix relative to the direction of rotation of the rotor, and the paper stock material that is not received by the screen moves approximately axially to the receiving outlet of the pressure sorter.

The stainless steel end rings may be welded in place at the ends of the screen portion to fit and support the screen in the screening hollow of the screening device. This application further describes a novel construction with a retaining ring of polymer, plastic or composite material cast in place over the exposed end of the spiral wound screen material. A pin or other retaining member is inserted through an opening in the screen material that is embedded in the ring material to act as an anchor to hold the end of the screen to the polymer or composite ring.

The present invention relates to a sorting for sorting raw materials for papermaking in a pressure-based sorting apparatus, the sorting surface being formed as a spirally or spirally wound sheet metal strip welded or joined at the periphery. Characterized as a cylinder member. The spiral cylinder may be supported on the end ring. The strip material is also preferably undulated across the width to increase the strength of the strip.

One or two end rings may be placed at one or both ends of the cylindrical screen plate according to the invention for the purpose of mounting on the papermaking screen and / or for sealing between spaces extending on either side of the plate. You may use it. Such a ring accommodates diametrical variations due to seams and / or ridges and acts to center the envelope cylinder face of the screen cylinder plate over the center of rotation of the screen rotor arrangement.

Another feature of the invention is a polymer in which one or more end rings are cast,
Composed of fiberglass, or composite material, the ends of the spiral wound screen are embedded in such material and held there by anchor members.

In another aspect of the invention, a papermaking screen member is formed with a sorting member defined as a spiral of continuous sheet metal strips joined by interlocking ends, the sheet metal strips having a high strength. Elongated to increase in length, the strips are perforated or formed with screening openings in the form of either holes or slots. The slots may extend longitudinally or laterally of the strip and may be prior to the process of forming the spiral tube or during a process such as parallel punching or cutting, or cutting, punching, piercing, or lasering. The openings may be formed in strips after the tube is formed by electrical discharge machining.

The screen according to the present invention also provides an unexpected advantage over conventional screen plates used in pressure sorting machines for papermaking. That is, the wall thickness of the screen reduces the receiving fiber to at least 50% or more of the normal thickness it must pass through the aperture or slot, and at least at the plate surface to reduce the effective length of the aperture. The possibility of blocking holes is reduced compared to the conventional screen plate without contouring. Thus, the thinner plate has reduced friction compared to plates of conventional thickness,
Fibers with reduced pressure can be sorted, which improves yield and efficiency.

To provide a lightweight screen cylinder member for selecting a raw material for papermaking which requires a material containing less metal as compared with a conventional screen, in which labor cost and general cost are reduced. Is an important object of the present invention.

An important aspect of the present invention is to provide the ability to use pre-punched material in the manufacture of paper stock sorting components.

Another advantage of the present invention is that the sorting member is formed into a spiral long tube, stored for future use, and a section cuts the tube to form the sorting member for the screen plate. That is.

Another advantage is a method of manufacturing a screen cylinder element for a papermaking screen, as described above, which comprises making a very long cylindrical tube from a long and substantially flat strip of perforated material, and then , A method of manufacturing a screen cylinder element comprising the step of cutting a tube into cylindrical segments of a desired axial length. Such a segment may be formed from a continuously formed spiral tube so that the segment is cut to form the tube.

These and other objects of the invention will be apparent from the following description, accompanying drawings and claims.

[0022]

DETAILED DESCRIPTION OF THE INVENTION

In the drawings illustrating the preferred embodiment of the present invention, a cylindrical screen cylinder member according to the present invention is designated by reference numeral 10 in FIGS. In FIG. 2, reference numeral 11 indicates a spirally wound screen portion or screen body having a generally cylindrical shape, which has peripheral edge portions received by the attachment rings 12 and 13, respectively. At least one of the mounting rings, such as ring 13 in FIG. 1, may be provided with conventional bolt openings 14 so that the screen cylinder member 10 may be mounted within a pressure sorting apparatus.

The cylindrical screen body 11 is a helix from a single continuous length or substantially planar strip of sheet metal by means of a spiral tube forming device, as shown in US Pat. No. 5,609,055. The tube is manufactured or rolled. The spiral screen body 11 has a spiral seam, as shown in FIG.
At 18, a continuous strip 16 of sheet material spirally cylindrically rolled and welded over the mandrel with butt ends rolled, rolled and optionally welded (FIG. 4). A plurality of parallel connected strips 15 formed as.

The planar spacing of the strips 16 between seams is preferably substantially sinusoidal, such as by rolling or forming flat sheet metal strips.
As shown in the partial cross-sectional view of FIG. 4, the corrugation pattern extends in the width direction of the strip so that the axis of the ridge (FIG. 2) extends parallel to the long axis direction of the strip. It is composed of inverted partial cylindrical arcuate portions whose radii are connected so as to form a continuous pattern of ridges 21 and valleys 22. However, the invention is not limited to the particular shape of the ridge as illustrated in FIG. The purpose of the ridges is to impart high radial stiffness to the co-connected strip segments. As shown in FIG. 4, the waviness due to the ridge is a seam 18
As well as bring an unexpected benefit. The undulations and the peripheral seam, together with the rotating foil, form a microdisordered area that helps to keep the holes or openings in the body 11 open.

The pattern of holes or openings 24 may be pre-formed in strip material, for example, from a common rolling of 0.60 inch thick stainless steel, as described above. Figure 5
Illustrates a preferred 60 ° pattern of perforated cylindrical openings 24, such as 0.008 inches or less or more. The present invention is not intended to be limited to a particular hole pattern or size.

FIG. 6 schematically illustrates a method of forming the pattern of slots 25 with a strip material. The spiral screen body 11 is made using a strip material without holes or slots, then laser cutting, electrical discharge machining, high pressure water cutting,
Alternatively, it is within the scope of the invention to form the desired opening through the formed cylindrical body by other equivalent means including mechanical cutting and punching. The particular advantage of the screen cylinder of the present invention is that the material used in the present invention 6 is relatively inexpensive and has a thickness allowing high speed drilling.

The seam or continuous seam 18 is formed in an interlocking manner with each adjacent end forming an interlocking loop 26. Here, the loop is the arrow 3 in FIG.
A pressure is applied in the direction indicated by 0 to roll hard. If desired, the seam may be continuous heat welded, such as with a flux or non-flux arc or high intensity current to form a solid and continuous seam.

The seam 18 shown in FIG. 8, consisting essentially of the material of the strip 16 of four thicknesses,
It may be placed on the "inner" or "outer" peripheral edge of the cylinder, as commanded by the rolling mill. In the case of the screen cylinder 10, the seam is on the inlet face,
Usually, it is preferably located on the inner surface of the screen. Since the impact foil is rotating, in this scheme the ridged, subtly stepped spiral ribs formed by the seam cause the spiral from one axial end of the screen to the other. Acts as a channel. The manner in which there is a component of rotational movement of the material in the axial direction that assists in carrying the rejects to the rejects outlet and away from the inlet face of the screen by selecting the helix and direction of rotation to guide the rejects to the outlet. The efficiency is ensured by guaranteeing. The seam also acts as a turbulence bar that keeps the screen holes open in cooperation with the rotating foil.

FIG. 3 illustrates the preferred method of attaching the helical screen body section 11 to one of the end rings, such as end ring 13. The end ring 13 is made of metal and has an L-shaped slot or opening 32. The cylindrical end of section 11 is inserted into the slot and welded in place, for example by weld 35. The opposite end ring 12 may be attached in the same manner.

As a preferred example, a 24-inch diameter, 24-inch high screen according to the present invention is
Shown using a stainless steel strip material with a wall thickness of 0.060 inch (16 gauge). The screen is undulated in the cross-sectional direction, the undulations of which the axis extends parallel to the ends of the screen and the helix lead angle is 20 ° as shown in FIG. The ridge pitch between the ridges 21 was 0.625 inches. The strips 15 are pre-drilled with holes 24 having a diameter of about 0.062 inches with a hole spacing of about 0.1 inches and exhibit an open area of about 12%.

Waviness strip 16 is typically 6 inches wide and exhibits an effective width of about 5.6 inches after seams 18 are formed at about 5.6 inch intervals by seaming. The radius of curvature of the ridge is about 0.19 inch (measured to the plate surface) and when taken with the plate, the effective thickness dimension, designated "d" in Figure 4, is 0.25 inch. The radial thickness of the screen at the seam is about 0.24 inches. The perforated openings have a 60 ° pattern,
The center-to-center distance A shown in FIG. 5 is 0.170. The end rings are made of stainless steel and attached as shown in FIG. The screen was 60 pounds.

It is also within the scope of the invention that the cheap and lightweight support ring, as shown in FIG. 7, is made of polymer, fiberglass, or composite material. The ring 36 is made of such composite or polymeric material and is cast in place for each of the axial ends of the body 11. A fixed anchor in the form of a pin 30 is inserted through a hole formed at the peripheral edge or at the edge of the sorting sheet material to be cast and, before hardening, the ring 36
It may be engaged with the forming material. A ring having the general ridges of the ring shown in FIG. 3 can be joined to both ends of the body 11. The use of a polymer or composite material in the ring allows a substantial cost savings, and the use of such a support ring is made possible by the inherent strength of the spirally undulating sorting body 11.

An apparatus for forming strips of sheet material into a continuous helix, such as the well-known technique shown in US Pat. No. 5,604,055, and apparatus for this purpose is US 999
It may be purchased from many companies, including Spiral-Helix, of Dearfield Parkway, Buffalo Grove, Illinois 60089. A spiral tube formed in this manner may have an indefinite length and a predetermined diameter, and after formation the proposed cylindrical screen body 11 taking into account the dimensions of the applied end rings. It may be cut to a length corresponding to the height. Thus, the sorting material can be formed into a spiral wound, as described above, and then cut to the desired axial length required for the particular device. It is necessary to provide cylinders of multiple diameters, typically, but not limited to 24 inches in diameter, which presents a simple matter of choice when installing the spiral tube forming device. The seam tube may also be formed continuously by the cut cylindrical segments as the tube is made.

[Brief description of drawings]

FIG. 1 is a plan view of a screen according to the present invention.

2 is a partial elevational view of the screen of FIG. 1. FIG.

FIG. 3 is a typical enlarged detail view taken along line 3-3 of FIG. 1 showing the screen portion attached to the metal end ring by a method such as welding.

FIG. 4 is a partially enlarged cross-sectional view of a lateral portion of a wavy strip of sheet material.

FIG. 5 is an enlarged plan view of a typical hole pattern used in the present invention.

FIG. 6 is a partial cross-sectional view of a strip of sheet metal showing one arrangement or pattern in which the screen is perforated.

FIG. 7 is a partial enlarged view showing a polymer, fiberglass or other composition ring attached to a screen strip material on one or both sides of the end ring.

FIG. 8 is an enlarged cross-sectional view through one of the seams joining the material ends of the spiral strip, showing the seam joining prior to rolling or welding.

[Explanation of symbols]

  10 screen cylinder   15 strips   18 seams   21,22 ridges   36 Polymer materials or composite materials

[Procedure for Amendment] Submission for translation of Article 34 Amendment of Patent Cooperation Treaty

[Submission date] February 13, 2001 (2001.2.13)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Contents of correction]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Contents of correction]

As a preferred example, a 24-inch diameter, 24-inch high screen according to the present invention is
Shown using a stainless steel strip material with a wall thickness of 0.060 inch (16 gauge). The screen is undulated in the cross-sectional direction, the undulations of which the axis extends parallel to the ends of the screen and the helix lead angle is 20 ° as shown in FIG. The ridge pitch between the ridges 21 was 0.625 inches. The strips 15 are pre-drilled with holes 24 having a diameter of about 0.062 inches with a hole spacing of about 0.1 inches and exhibit an open area of about 12%.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Contents of correction]

Waviness strip 16 is typically 6 inches wide and exhibits an effective width of about 5.6 inches after seams 18 are formed at about 5.6 inch intervals by seaming. The radius of curvature of the ridge is about 0.19 inch (measured to the plate surface) and when taken with the plate, the effective thickness dimension, designated "d" in Figure 4, is 0.25 inch. The radial thickness of the screen at the seam is about 0.24 inches. The perforated openings have a 60 ° pattern,
The center-to-center distance A shown in FIG. 5 is 0.170. The end rings are made of stainless steel and attached as shown in FIG. The screen was 60 pounds.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Change

[Contents of correction]

It is also within the scope of the invention that the cheap and lightweight support ring, as shown in FIG. 7, is made of polymer, fiberglass, or composite material. The ring 36 is made of such composite or polymeric material and is cast in place for each of the axial ends of the body 11. A fixed anchor in the form of a pin 30 is inserted through a hole formed at the peripheral edge or at the edge of the sorting sheet material to be cast and, before hardening, the ring 36
It may be engaged with the forming material. A ring having the general ridges of the ring shown in FIG. 3 can be joined to both ends of the body 11. The use of a polymer or composite material in the ring allows a substantial cost savings, and the use of such a support ring is made possible by the inherent strength of the spirally undulating sorting body 11.

─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor David E. Chupka             United States Ohio 45042 Mid             Le Town Heinkel Road 125 (72) Inventor Garry S. Williamson             United States Ohio 45042 Mid             Le Town Moshiman Road 5429 (72) Inventor Stephen M Wedley             United States Ohio 45044 Mid             Le Town Solls Circle 4809 F-term (reference) 4D071 AA03 AB62 DA20                 4L055 CB26 CB31 FA22 FA30

Claims (19)

[Claims] 1. A screen cylinder for use in a pressure type sorting apparatus having a rotary impact member for sorting a raw material for papermaking, comprising a substantially cylindrical screen body made of a spirally wound strip sheet metal material. A screen cylinder having a locking seam formed at a peripheral end portion of the strip, and the strip having an opening for selecting a raw material for papermaking. 2. The strip is formed to have ridges in the cross-sectional direction of its width, the axes of the ridges extending substantially parallel to each other and substantially parallel to the peripheral edge of the strip. Item 1. The screen cylinder according to Item 1. 3. A peripheral edge of the strip is intermeshed with an adjacent peripheral edge of the spiral strip to provide beam strength to the cylinder having a thickness of about four times the thickness of the strip. The screen cylinder according to claim 1, wherein a lock seam is formed. 4. The screen cylinder according to claim 3, wherein the peripheral edge of the strip is made of stainless steel. 5. The end ring of claim 1 made of stainless steel.
The screen cylinder according to any one of 1. 6. The end ring comprises a non-metallic composite material or a polymeric material,
A ring-shaped locking anchor extends through the strip opening at the peripheral edge of the sorting member and is embedded in the ring to retain the ring on the screen body. The screen cylinder according to any one of claims. 7. A substantially cylindrical surface of the screen body is an entrance surface,
7. A screen as claimed in any one of claims 2 to 6 in which the ridge of the ridges is arranged to move to the peripheral rejects outlet by a pitch of the ridges related to the direction of flow through the pressure device. cylinder. 8. A screen cylinder for use in a pressure type sorting apparatus having a rotary impact member that is moved near the screen surface for sorting papermaking raw materials, the screen cylinder comprising a substantially cylindrical screen body and a strip lock. A seam formed with the strip ends at the peripheral edges, the body comprising a single strip of helically wound sheet material, the strip extending substantially longitudinally of the strip material. A screen cylinder, which is corrugated to have ridges and which has openings formed as holes through the strip material for selecting papermaking ingredients. 9. A metal cylindrical screen plate for selecting a raw material for papermaking, which comprises one or more long and substantially flat strips of a spirally wound perforated material, the screen plate being selected during the sorting operation. A metal cylindrical screen plate having a spiral seam connected to the peripheral edge of the strip, including a portion of the strip, to provide radial stiffness and strength to resist the forces applied to the screen plate. 10. A helical seam or seam comprising a crimped and fixed joint at the proximal end of the strip, the resulting thickness of the seam being four times the thickness of the strip of perforated material. The screen plate according to claim 6, which is doubled. 11. The screen plate according to claim 9, wherein the ends of the seams are fixed together by welding or brazing. 12. The screen plate of claim 9, wherein the spiral seams are secured together by crimping and welding or brazing. 13. The method of claim 9 wherein the portion that provides radial stiffness comprises a ridge and a trough extending substantially parallel to the ends of the strip and seam. The screen plate according to claim 1. 14. One or two end rings located at one or both ends of the cylindrical screen between spaces intended for mounting on a papermaking screen and / or extending on either side of the plate. 10. A screen plate according to claim 9 including an end ring for the purpose of sealing the ring, said ring being adapted to diametrical variations due to seams and / or ridges and on the center of rotation of the screen rotor. A screen plate that acts to center the envelope cylindrical surface of the cylindrical screen plate on the. 15. The end ring is metal and is welded, brazed,
Alternatively, it is connected to the cylindrical screen plate by an adhesive.
The screen plate described in. 16. The screen plate of claim 14, wherein the end rings are metal and mechanically connected by either pins, screws or rivet means and extend on one side of the screen plate. A screen plate comprising a rubber or plastic material between the cylindrical screen plate and the end ring to seal between spaces. 17. The screen plate according to claim 14, wherein the end ring is made of a non-metallic decoding material or a polymeric material and is bonded to the screen plate by either a rivet, a strip, a pin, an anchor or an adhesive. . 18. A method of manufacturing a screen cylinder for a papermaking screen according to any one of claims 9 to 17, wherein a very long cylindrical tube from the long and substantially flat strip of perforated material. And then cutting the tube into cylindrical segments of desired axial length. 19. The method of manufacturing a screen cylinder according to claim 9, further comprising a step of forming a spiral tube substantially continuously and cutting the tube into cylindrical segments when the tube is manufactured.