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BR-112020006283-B1 - REFINING PLATE, AND, REFINER FOR MECHANICAL TREATMENT OF ORGANIC/CELLULOSIC MATERIAL

BR112020006283B1BR 112020006283 B1BR112020006283 B1BR 112020006283B1BR-112020006283-B1

Abstract

A refining plate (1) is described which is adapted to be affixed to a rotating refining disc (10) in a refiner (100) for the mechanical treatment of lignocellulosic material. The refining plate (1) comprises a refining surface (11) which is adapted to be disposed opposite a second refining surface (21) of a second refining disc (20) in said refiner (100). The refining surface (11) is provided with a plurality of refining bars (110), wherein at least one of the refining bars (110) is provided with cavities (111) which are at least partially embedded in the refining bars. Furthermore, at least one cavity (111) provided in at least one refining bar (110) has one end (111a) disposed closer to the leading edge (112) of a refining bar (110) and one end (111b) disposed closer to the trailing edge (113) of the refining bar, wherein the depth dimension of the cavity at end (111a) is less than the depth dimension of the cavity at end (111b).

Inventors

  • Thommy Lindblom

Assignees

  • VALMET AB

Dates

Publication Date
20260317
Application Date
20181120
Priority Date
20171201

Claims (10)

  1. 1. A refining plate (1) adapted for attachment to a rotating refining disc (10) in a refiner (100) for the mechanical treatment of lignocellulosic material, said refining plate (1) comprising a refining surface (11) adapted for attachment to a second refining surface (21) of a second refining disc (20) in said refiner (100), wherein said refining surface (11) is provided with a plurality of refining bars (110), wherein the refining plate (1) is characterized in that at least one of the refining bars is provided with cavities (111) which are at least partially embedded in said refining bar (110) and that at least one cavity (111) provided in said at least one refining bar (110) has an elongated shape extending between one end (111a) disposed closer to the leading edge (112) of a refining bar (110) and one end (111b) disposed closer to the trailing edge (113) of said refining bar and wherein the depth dimension of the cavity at end (111a) is less than the depth dimension of the cavity at end (111b).
  2. 2. Refining plate (1) according to claim 1, characterized in that said cavities (111) are provided in said refining bars (110) in such a way that an angle A, 0° < A < 45°, preferably 5° < A < 45°, is formed between the length direction of the cavities (111) and the length direction of the bars (110).
  3. 3. Refining plate (1) according to claim 1 or 2, characterized in that said cavities are provided in said refining bars (110) such that the length direction of said cavities (111) forms an angle of inclination B, 0° < B < 45°, preferably 5° < B < 45° with the direction normal to said refining surface (11).
  4. 4. Refining plate (1) according to any one of claims 1 to 3, characterized in that said cavities (111) have an elongated shape and are provided in said refining bars (110) in such a way that they have one end (111a) that is disposed closer to the leading edge of the refining bar (110).
  5. 5. Refining plate (1) according to any one of claims 1 to 4, characterized in that at least one cavity (111) provided in said at least one refining bar (110) has one end (111a) disposed closer to the leading edge (112) of a refining bar (110) and one end (111b) disposed closer to the trailing edge (113) of said refining bar (110) and wherein the width dimension of the cavity at the end (111a) closer to the leading edge (112) of said refining bar (110) is smaller than the width dimension of the cavity at the end (111b) closer to the trailing edge (113) of said refining bar (110).
  6. 6. Refining plate (1) according to any one of claims 1 to 5, characterized in that at least one of the refining bars (110) is provided with cavities (111) having an intermediate spacing D, wherein the intermediate spacing D is greater than or equal to the width W of said refining bar.
  7. 7. Refining plate (1) according to any one of claims 1 to 6, characterized in that at least one cavity (111) provided in at least one of said refining bars (110) has one end (111b) disposed closer to the leading edge (112) of said refining bar and one end (111a) disposed closer to the trailing edge (113) of said refining bar (110), wherein the end (111a) disposed closer to the leading edge (112) of the refining bar begins at a distance L from the leading edge of the refining bar (110), said distance L being in the range: 0 < L < 1/2W, wherein W represents the width of the refining bar (110).
  8. 8. Refining plate (1) according to any one of claims 1 to 7, characterized in that at least one of said cavities (111) is completely embedded in said refining bar (111), thus forming a channel that extends into the refining bar (110).
  9. 9. Refining plate (1) according to any one of claims 1 to 7, characterized in that at least one of said cavities (111) comprises a recess in the upper surface of the refining bar (110), thus forming a cavity that is partially embedded in said refining bar (110).
  10. 10. Refiner (100) for mechanical treatment of organic/cellulosic material, said refiner (1) characterized in that it comprises two opposingly arranged refining discs (10, 20), wherein at least one of said refining discs (10, 20) comprises a rotating refining disc and at least one of said refining discs (10, 20) comprises a refining plate (1) according to any one of claims 1 to 9.

Description

FIELD OF TECHNIQUE [001] The proposed technology refers, in general, to a refining plate for a disc refiner. More particularly, it refers to a refining plate comprising refining bars for mechanical treatment of material in a refiner, wherein at least some of the refining bars in the refining plate are provided with cavities that create a rim. FUNDAMENTALS OF THE INVENTION [002] Common mechanical pulp refiners generally comprise two relatively rotating discs, for example, a stationary disc and a rotating disc, to which a refining plate, also called a refining element or refining segment, is coupled. During the use of the refiner, lignocellulosic material, such as wood fibers, is mechanically treated, for example, crushed or worked, between the refining plates of the two relatively rotating discs. To obtain effective material treatment, it is quite common to provide the refining surface of the refining plates with refining bars that extend radially along the plate, so that both the refining bars themselves and the grooves that will be defined between the refining bars provide an improved crushing action. The leading edges of the bars, that is, the edges of the refining bars which, during the rotation of the refining plates, are placed in contact with the material, also act to provide separation and fibrillation of the fibers, while the grooves allow both the transport of the fibers as well as the removal of any vapor produced during the crushing action. Common refining plates can also be provided with structures known in the art as weirs. Weirs are also extended structures that are provided in the grooves of the refining plate and their main purpose is to cut off or interrupt the flow of material in the grooves in order to keep the material in the crushing or refining area for a longer period of time. [003] The structures provided in the refining plates, that is, the bars, grooves and weirs, are, however, affected during use by substantial forces due, INTER ALIA, to the high speed of rotation of the rotating disc(s). The speed of rotation in combination with any debris present in the organic material will cause substantial wear on the refining bars. [004] As a consequence of wear, the leading edges of the refining bars can be smoothed, so the efficiency of a refining plate will be negatively affected. A refining bar with a smoothed leading edge will lose many of the positive effects mentioned above. [005] In document SE 513807, a particular solution to this problem is proposed. The proposed solution is based on providing refining bars whose upper surface is provided with an elevation so that at least two edges arranged at different heights are created on the refining bar. [006] Although this solution is quite satisfactory for extending the service life of a refining plate, the added structures may negatively affect the material flow in the refining plate. [007] There is therefore a need in the art to further improve refining plates and, in particular, to provide at least a partial solution to the problem of deterioration of refining bars in a refining plate, while at the same time reducing any impact on material flow. [008] Document EP1185369A1 discloses a refining element, intended for disc-type refiners, for working fibrous material, wherein the refining element is formed with a pattern of bars with upper surfaces and edges and intermediate grooves. On the upper surfaces of the bars, at least one step is formed, so that at least two longitudinal edges are formed on the bars arranged at different heights. SUMMARY OF THE INVENTION [009] It is an objective of the proposed technology to provide a refining board that has an extended service life. [0010] Another objective of the proposed technology is to provide a refining plate equipped with refining rods, in which even worn refining rods provide good refining action. [0011] Another objective of the proposed technology is to provide a refining plate with an extended service life that reduces the impact on material flow in the refining plate. [0012] Yet another objective of the proposed technology is to provide a refiner equipped with refining plates with an extended service life. [0013] These and other objectives are met by modalities of the proposed technology. [0014] According to a first aspect, a refining plate is provided adapted for attachment to a rotating refining disc in a refiner for the mechanical treatment of lignocellulosic material. The refining plate comprises a refining surface adapted for disposal opposite a second refining surface of a second refining disc in the refiner. The refining surface is provided with a plurality of refining bars, wherein at least one of the refining bars is provided with cavities that are at least partially embedded in the refining bar and at least one cavity provided in at least one refining bar has one end disposed nearer the leading edge of a refining bar and one end disposed nearer the trailing edge of the refining