WO2006091063A1

WO2006091063A1 - Refining sector and production method thereof

Info

Publication number: WO2006091063A1
Application number: PCT/MX2006/000001
Authority: WO
Inventors: Julio Antonio TREVIÑO MORALES
Original assignee: Trevino Morales Julio Antonio
Priority date: 2005-02-22
Filing date: 2006-01-05
Publication date: 2006-08-31
Also published as: MXNL05000017A

Abstract

The invention relates to a refining sector for the refining disc of a machine used to refine a ligno-cellulosic fibrous material or other natural or synthetic materials. The refining sector is formed by: two or more radially-adjacent refining sections which are used to perform one or more refining steps, each of said sections comprising one or more refining portions which are characterised in that they are equipped with a plurality of bars and grooves; and one or more removal channels which are provided between adjacent refining sections. Alternatively, the refining sector can comprise a plurality of distribution channels for distributing the paste between the refining portions, the bars and the grooves. The invention also relates to the refining disc that is formed by a plurality of the inventive refining sectors and to a method of producing said refining sectors based on changeable refining section models.

Description

REFINING SECTOR AND MANUFACTURING METHOD

TECHNICAL FIELD OF THE INVENTION

This invention relates to refining sectors intended to be used in refining discs of refining machines to refine lignocellulosic fibrous materials and other natural or synthetic materials. The invention relates more precisely to a refining sector and a manufacturing method thereof.

BACKGROUND OF THE INVENTION

Currently a refining machine of lignocellulosic fibrous material and other natural or synthetic materials consists of two opposite refining discs that rotate with respect to each other, of which one or both are rotating. In the refining discs a plurality of refining sectors are disposed that have a surface with a design of intermediate bars and grooves. The refining discs are positioned so that the refining sectors form a refining gap, through which the fibrous material is destined to pass out from within the refining discs, whereby the disintegration of the fiber is carried carried out by the bars of the refining sectors. Said bars can be of various designs and, therefore, can be continuous or discontinuous and are of uniform or variable height. In most cases, toothed bars can be used.

The fibrous material is first defibrated in the refining gap between the refining surfaces, that is, the fibers are released, which takes place in the inner portion of the refining gap in which the distance between the surfaces of Refining is the greatest of all. Next, the refining gap narrows outwardly so that the desired refining of the fibrous material is obtained. To produce this refining, large amounts of energy are required.

The refining surfaces are formed in different ways, which depend on the degree of refining desired and therefore on the quality of the desired paste. Paste quality is also affected by other factors, for example refining gap size, liquid content in the fibrous material, feed rate, temperature, and so on.

The appearance of the refining surfaces is of great importance, especially in relation to the length of the fiber of the refined material. With a substantially radial orientation of the bars on the refining surfaces, a large proportion of long and well defibrated fibers is obtained in the paste. This can be explained by the fact that the fibrous material orients itself in the refining interstitium with the fiber direction essentially parallel to the edges of the bar. For that reason, defibration and refining take place because the fibrous material rolls substantially between the bars on opposite refining surfaces, so that the fibers are released and defibrillated along their entire length. This type of pulp is highly resistant and is therefore particularly used, for example for printing paper. The energy consumption in the manufacture of this type of pasta is relatively high.

With an oblique orientation of the bars with respect to the radius, the proportion of long fibers in the pulp decreases, because in this case the edges of the bars exert a cutting effect on the fibrous material. At the same time as the cutting effect increases, the fibrillation effect decreases. The resistance properties of this type of paste They are certainly lower, but the pulp is particularly suitable for the manufacture of fine paper qualities.

The angle of inclination of the bar is also important for feeding the material through the refining gap. When the bars have an oblique inclination angle and outwardly backward in the direction of disc rotation, a pumping action is obtained outwards, while at a tilt angle in the opposite direction it produces a braking effect. Thus, the time of stay of the material in the refining gap is affected by the angle of inclination of the bars and their location either for pumping or refining.

Examples of refining discs or their refining sectors that are currently known are described by IMiIs Virving in European patents EP-0,611,599 and EP-0,702,597; Anders Hawen, et al. in European patent EP-0,633,813; Per Frober, et al. in European patent EP-0, 767,706; NiIs Virving, et al. in European patent EP-0,958,058; and John B. Matthew in United States patents US-5,740,972, US-5,921,486 and US-5,954,283.

The known refining discs and refining sectors, as well as those described in the previous documents, are formed in order to produce desired properties of the paste. This implies in many cases that commitments must be made regarding the design of the refining surfaces in order to produce an adequate balance between fibrilization and fiber cutting and between feeding and braking, respectively. By

Therefore, from these limitations, it is then necessary to offer a refining sector and a manufacturing method thereof, which allow a refining disc to be formed to produce an optimal paste and at the same time minimize energy consumption and cause less wear on the bars, such that these refining sectors meet the different requirements of the industry without having to be limited to having several types of refining sectors for specific production purposes.

SUMMARY OF THE INVENTION

In view of what has been previously described and with the purpose of solving the limitations found. It is an object of the invention to offer a refining sector for refining disc of a refining machine of fibrous material, the refining sector is formed by two or more adjacent refining sections in radial direction to perform one or more refining work steps, such that each of the refining sections is formed by one or more refining portions that include a plurality of bars and grooves; and one or more removal channels between adjacent refining sections.

It is also the object of the invention to offer a changeable refining section model to form a refractory cast mold of a refining sector for refining disc, the refining section model is formed by one or several groups of bars and grooves; and one or more channels between the groups of bars and adjacent grooves.

Another object of the invention is to offer a method for manufacturing refining sectors for refining disc, the method starts by determining one or more refining work steps to be performed by the refining sector; continuing with the selection of one or more models of changeable refining sections to form a refractory cast mold of the refining sector with the models of changeable refining sections selected; and thus make the casting part of the refining sector from the refractory mold.

Finally, a refining disc for a refining machine of fibrous material is also object of the invention, the refining disc is formed by two or more generally circular refining crowns for one or more refining work stages, where each of the crowns refining include one or more refining portions, characterized by including a plurality of bars and grooves; and one or more removal channels between adjacent refining crowns.

BRIEF DESCRIPTION OF THE FIGURES

The characteristic details of the invention are described in the following paragraphs in conjunction with the accompanying figures, which are for the purpose of defining the invention but without limiting its scope.

Figure 1 illustrates a schematic view of a refining sector according to the invention.

Figures 2A, 2B and 2C illustrate the models of refining sections for manufacturing a refining sector. Figure 2A is a top view of models of changeable refining sections; Figure 2B is a side sectional view of the models of refining sections and a molding plate and Figure 2C is a top view of the molding plate with the models of refining sections and the rear model. Figures 3A and 3B illustrates two cooperating refining discs in a refining machine according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to Figure 1, which shows a schematic view of a refining sector according to the invention. The refining sector 10, for use in a refining disc of a refining machine of fibrous material, is formed by two or more refining sections. In this case, Figure 1 shows two refining sections 20 and 30 adjacent in radial direction and separated from each other by a removal channel 40. In turn, each of the refining sections 20 and 30 are divided into one or more portions of refining 50, such that the adjacent refining portions 50 within the same refining section 20 or 30 are separated by distribution channels 60.

Each of the refining portions 50 within the same refining section 20 or 30 is formed by a plurality of rods 70 and grooves 80 whose width, depth and angle of inclination is substantially the same. The bars 70 of the refining section 20, which will be closer to the center of the refining disc (not shown), start from an end or ascending inlet 90 in a generally triangular shape; while the bars 70, of each refining portion 50, which are adjacent to the distribution channels 60 have a triangular start.

The refining sector 10 being formed by two or more refining sections 20 and 30 has at least a double action or refining work stage to be performed during the refining process of the fibrous material. Therefore, the depth and angle of inclination of the bars 70 and grooves 80 of adjacent refining portions 50 in radial direction between the refining sections 20 and 30, are generally the same; while the width of the bars 70 and grooves 80 must not necessarily be the same. That is, the refining sector 10 can have a refining section 20 whose bars 70 and grooves 80 can have a width equal to or different from the width of the bars 70 and grooves 80 of the other refining section 30, this with the purpose of refining sections 20 and 30 performing a different refining work stage in the fibrous material within the refining process. For example, in the case that the width of the bars 70 and grooves 80 of the refining section 20 is greater than the width of the bars 70 and grooves 80 of the refining section 30, the refining section 20 performs the work of cutting and a first job of defibration of the fibrous material; while the refining section 30 performs the final defibration work and decreases the cutting effect.

Other examples of the foregoing are that the refining sector 10 may have a first refining section 20 to perform a cutting stage combined with a second refining section 30 to simultaneously perform a defibration stage; or a refining sector 10 having a first refining section 20 to perform a cutting and defibration stage combined with a second refining section 30 to perform a second finer defibration stage; or a refining sector 10 that has a first refining section 20 to perform the cutting stage combined with a second refining section 30 to perform a first defibration stage combined with a third refining section (not shown) that performs a second stage of final defibration.

The ascending entrances 90 of each of the bars 70 of the refining section 20 allow the pulp of incoming fibrous material, which comes from the center of the refining machine (not shown), to be distributed among all the refining portions 50; while the distribution channels 60 are redistributing the pulp of fibrous material between the bars 70 and grooves 80 of each refining portions 50 as the pulp flows out of the refining section 20.

The removal channel 40 optimizes the removal of the paste by allowing the pulp of fibrous material to be removed that could not be removed within a refining work stage carried out in a previous refining section, so that this paste is used in the next stage of refining work to be carried out by the next refining section and so on as the paste advances between the refining sections. This removal channel 40 in conjunction with the distribution channels 60 of the following refining section allow the pulp of fibrous material, which comes from the previous refining section, to be distributed between the refining portions 50 and between its bars 70 and grooves 80 for a next stage of refining work as the paste flows out of the next refining section.

It should be mentioned that the refining sector 10 can be made in a single casting or by separate castings, which could be the refining sections 20 and 30, which are placed adjacently to form said sector. The refining sector 10 also has fastening means such as through holes 100 to be arranged and distributed in the refining sections 20 and 30, such that the refining sector 10 can be attached to the refining disc.

Changing now to Figures 2A, 2B and 2C. Figure 2A illustrates models of changeable refining sections 120 and 130 to form a refractory cast mold of a refining sector. Each refining section model is formed by one or several groups of bars and grooves 150 and one or more channels 160 between the groups of bars and adjacent grooves, which allow forming the mold for the bars 70 and grooves 80 and the mold of the distribution channels 60 of a refining sector respectively.

In order to manufacture a refining sector 10 from a foundry part, first the refining work steps to be carried out by the refining sector are determined by selecting two or more models of refining sections 120 and 130 separately and combined adjacently. in the radial direction, they can form a cast mold for a refining sector that complies with such refining work steps. These models of refining sections 120 and 130 are changeable on a molding plate 110, that is to say that they can be removed and changed by other models of refining sections in order to form as many foundry molds as are necessary to make both refining sectors that perform two or more stages of refining work according to refining requirements of the fibrous material required for an application.

As shown in Figures 2A and 2B, once the models of refining sections 120 and 130 have been selected, they are mounted and fastened on the molding plate

110 adjacently and in the radial direction, so that if the models of refining sections are mounted with a radial separation from each other, then the mold for the removal channel is formed between both models of refining sections.

In another part of the same molding plate 110 or in another molding plate separately, a subsequent model 140 of the refining section to be manufactured is mounted and secured. Once you have the models of the refining sections 120 and 140 and the rear model 140 on the molding plates 110 (Figure 2C), according to the procedures known in the state of the art, the mold is formed refractory of casting with refractory sand to later make the casting part of the refining sector by emptying the molten metal in the mentioned mold and finally removing the piece of solidified refining sector to proceed to its subsequent rectification process.

This manufacturing method that allows to have models of changeable refining sections allows to form a plurality of molds of refining sectors to manufacture a plurality of refining sectors 10 that cover multiple requirements within the industry, since it allows to combine two or more section models of refining of the same or different angle of inclination and width of the bars and grooves to form a mold of refining sector to manufacture a refining sector 10 that performs two or more stages of refining work. For example, in the case that there are five models of refining sections that correspond to the refining section 20 (see Figure 1), each with different bar widths and grooves, and five models of refining sections that correspond to the refining section 30 (see Figure 1), each with different bar widths and grooves, but whose widths correspond one by one with the bar widths and grooves of the refining section models of the refining section 20, then You can have up to forty-five possible combinations of forming molds of refining sectors to form forty-five refining sectors 10 with two or more stages of refining work.

The manufacturing method, according to the described invention, represents an advantage over the current manufacturing methods of refining sectors belonging to the state of the technique, since to form forty-five different refining sectors would require forty-five models of different refining sectors with current methods; but when using the manufacturing method of the invention, which is based on molds of changeable refining sections, only ten separate refining model models are required.

Figures 3A and 3B illustrate two cooperating refining discs in a refining machine. Each disk is formed by a series of refining sectors 10 such that the refining sections 20 and 30 together form at least two refining crowns, generally circular in shape, which are adjacent to each other in radial direction. In one embodiment of the refining disc, it has a radial removal channel 40 between the refining crowns and a plurality of distribution channels 60. Each circular refining crown is formed by a plurality of refining portions 50 that can be separated with each other through the distribution channels 60 and such that each refining portion 50 has a plurality of bars 70 and grooves 80. In the first circular refining crown, the bars 70 begin with an ascending end or inlet 90 in a triangular shape.

Based on the embodiments described above, it is contemplated that the modifications of the described realization environments, as well as the alternative realization environments will be considered evident to a person skilled in the art of the technique under this description. It is therefore contemplated that the claims encompass such modifications and alternatives that are within the scope of the present invention or its equivalents.

Claims

1. A refining sector for refining disc of a refining machine of fibrous material, the refining sector comprises: two or more adjacent refining sections in radial direction to perform one or more stages of refining work, where each of the refining sections include one or several refining portions, characterized by including a plurality of bars and grooves; and one or more removal channels between adjacent refining sections.

2. The refining sector of claim 1, wherein it also includes a distribution channel between adjacent refining portions in the same refining section.

3. The refining sector of claim 1 wherein the bars and grooves of each refining portion are characterized by being generally parallel and having a generally equal angle of inclination.

4. The refining sector of claim 1 wherein the bars and grooves of adjacent refining portions in the radial direction between refining sections are characterized by having a generally equal angle of inclination.

5. The refining sector of claim 1 wherein the bars and grooves of each adjacent refining portion in radial direction between refining sections are characterized by having the same or different width.

6. The refining sector of claim 1 wherein the bars of the lower section of refining are characterized by having a rising end in a triangular shape.

7. The refining sector of claim 1 wherein it also includes one or more through holes for clamping distributed between the refining sections.

8. The refining sector of claim 1 wherein said sector can be made in a single casting or by separate castings.

9. A changeable refining section model to form a cast refractory mold of a refining sector for refining disc, the refining section model comprises: one or more groups of bars and grooves; and one or more channels between the groups of bars and adjacent grooves.

10. The refining section model of claim 9 wherein the bars and grooves of each group are characterized by being generally parallel and having a generally equal angle of inclination.

11. The refining section model of claim 9 wherein the bars and grooves of each group are characterized by having a generally equal width.

12. The refining section model of claim 9 wherein the bars are characterized by having a rising end in a triangular shape.

13. The refining section model of claim 9 wherein it also includes one or more through holes.

14. A method for manufacturing refining sectors for refining disc, the method comprises the steps of: determining one or more refining work steps to be performed by the refining sector; select one or more models of changeable refining sections under the determination of the refining work steps to be performed by the refining sector; form a refractory cast mold of the refining sector with the selected changeable refining section models; and making the casting part of the refining sector from said refractory mold.

15. The manufacturing method of claim 14 wherein the step of selecting one or more models of changeable refining sections under the determination of the refining work steps to be performed by the refining sector, includes the step of combining in Refining sections models an adjacent radial order according to the refining work steps to be performed.

16. The manufacturing method of claim 15, wherein it also includes the step of leaving a radial separation between the models of adjacent refining sections to form the removal channel.

17. The manufacturing method of claim 14, wherein it also includes the step of rectifying the casting part of the refining sector.

18. A refining disc for refining machine of fibrous material, the refining disc comprises: two or more generally circular refining crowns for one or more refining work steps, wherein each of the refining crowns includes one or more refining portions, characterized by including a plurality of bars and grooves; and one or more removal channels between adjacent refining crowns.

19. The refining disc of claim 18, wherein it also includes a distribution channel between adjacent refining portions in each refining crown.

20. The refining disc of claim 18 wherein the bars and grooves of the refining portions of any of the refining crowns are characterized by being generally parallel and having a generally equal angle of inclination.

21. The refining disc of claim 18 wherein the adjacent refining portions in the radial direction between adjacent refining crowns are characterized by having a generally equal angle of inclination.

22. The refining disc of claim 18 wherein the bars and grooves of each adjacent refining portion in the radial direction between adjacent refining crowns are characterized by having the same or different width.

23. The refining disc of claim 18 wherein the bars of the refining crown closest to the center of the disk are characterized by having a triangular shaped rising end.