WO2014091084A1

WO2014091084A1 - Method for processing fibre material

Info

Publication number: WO2014091084A1
Application number: PCT/FI2013/051164
Authority: WO
Inventors: Jari KÄYHKÖ; Esa SAUKKONEN; Juhani TURUNEN; Kari Kurronen
Original assignee: Mikkelin Ammattikorkeakoulu Oy
Priority date: 2012-12-14
Filing date: 2013-12-13
Publication date: 2014-06-19
Also published as: RU2015127756A; EP2935691A1; EP2935691A4; RU2654391C2; FI20126308A; FI126094B; CN105008618A

Abstract

According to one exemplary embodiment, the application relates to a method (100) for processing a fiber material, comprising refining (130, 140) the fiber material, which is used in the manufacture of a fibrous product and which contains fibers, for promoting its pulping and/or chemical treatment. In the method, the fiber material refining (130) is conducted as compression refining performed by using a vibrating crusher.

Description

METHOD FOR PROCESSING FIBRE MATERIAL Technical field

The application relates generally to a method for processing a fiber material. Background Fiber pulp and chips are traditionally refined with blade refiners for separating the fibers and working the fibers to a condition optimal from the standpoint of a product to be manufactured therefrom, as well as the production process. Refining is a critical step in the manufacturing process for fibrous products. Refining is typified by high energy consumption, as well as by a deterioration of cer- tain properties in fibers ^"and products manufactured therefrom, such as a reduction of fiber content, as well as a decline in dewatering, tear strength, and paper thickness. The current refining technology is still far from a theoretical optimum in terms of energy consumption and quality characteristics.

Compression refining useful for fiber material has been a subject of several earlier studies regarding the refining of chemical pulp, and pilot machines in relation to the studies have been constructed, but such pilot machines are not applicable for use in the production process. The application of a compression treatment to mechanical pulp has been discussed for example in patents US 5,540,392 and US 7,758,720 B2, but these involve the use of screw compres- sion type equipment.

Summary

One objective of the invention is to improve the processing of fiber material in view of reducing the consumption of energy needed for pulping and working of the fibers and upgrading properties of the fibers. The one objective of the invention is attained with a method of claim 1 , a vibrating crusher of claim 4, and a vibrating crusher use of claim 5.

A method according to one embodiment for processing a fiber material comprises refining the fiber material, which is useful in the manufacture of a fibrous product and which contains fibers, for promoting its pulping and/or chemical treatment. In the method, the fiber material refining is carried out in compression refining which is conducted by using a vibrating crusher.

The tern "fiber material" is used for example in reference to chips used as a raw material in the manufacture of paper and/or board, and/or to mechanical, chemi-mechanical or chemical (cellulose) pulp made from an organic fibrous material. The fiber material comprises a wood-based material and/or a non- wood based, for example a reed or straw type material, for example bamboo and/or cotton.

The term "fiber product" is used for example in reference to paper, board, as well as to a composite material containing micro- and/or nanocellulose. The fiber product may also refer to biofuel produced from a lignocellulose-based material.

The term "pulping" is used for example in reference to a breakup of the fiber material into fiber bundles consisting of fibers in contact with each other, and/or into individual fibers.

The term "chemical treatment" is used for example in reference to chemical treatments intended for the delignification of a material, for example to sulfate and/or sulfite digestion, oxygen bleaching, and acidic and alkaline treatments used in the manufacture semi-chemical pulps. In addition, the chemical treat- ment refers for example to chemical treatments intended for the bleaching of a fiber material, for example to bleaching based on peroxide- dithionite- and/or chlorine-based chemicals. Reference is also made for example to chemical treatments, for example to TEMPO and enzyme treatments used in the production of micro- or nanocellulose. The term "compression refining" is used for example in reference to the treatment of chips and/or fibers by compressing a fiber material, thereby facilitating pulping of the fiber material and/or increasing internal fibrillation and modifiabil- ity of the fibers.

The term "vibrating crusher" is used for example in reference to a vibrating crusher or a vibrating grinder, wherein compression is traditionally used for crushing for example aggregate by means of a crushing cone present in a crushing chamber (zone). In aggregate crushing, the aggregate is conveyed into a crushing chamber and trapped between a crushing cone and a wall of the crushing chamber, such that the aggregate to be crushed is comminuted to smaller pieces, into gravel or stone ash.

The vibrating crusher according to one embodiment intended for processing a fiber material is provided with a crushing chamber, which comprises feed ele- ments comprising at least one inlet opening, discharge elements comprising at least one outlet opening, and at least one crushing cone or crusher installed in the crushing chamber and adapted to press the fiber material against at least one internal surface of the crushing chamber, said feed elements being adapted to supply the crushing chamber with a fiber materia! to be refined by compression, and said discharge elements being adapted to remove the fiber material refined by compression from the crushing chamber. The vibrating crusher is adapted to refine by compression a fiber material, which is useful in the manufacture of a fibrous product and contains fibers, for promoting its pulping and/or chemical treatment. In the vibrating crusher use according to one embodiment, intended for processing a fiber material, the vibrating crusher is used for refining by compression a fiber material, which is useful in the manufacture of a fibrous product and contains fibers, for promoting its pulping and/or chemical treatment. The vibrating crusher is provided with a crushing chamber, which comprises feed elements comprising at least one inlet opening, discharge elements comprising at least one outlet opening, and at least one crushing cone (crusher) installed in the crushing chamber and adapted to press the fiber material against at least one internal surface of the crushing chamber, said feed elements being adapted to supply the crushing chamber with a fiber material to be refined by compression, and said discharge elements being adapted to remove the fiber material refined by compression from the crushing chamber.

Other embodiments are presented in the dependent claims.

A method according to the embodiments, intended for the pretreatment of a fiber material, enables a speedier refining of the fiber material, a saving in total refining energy consumption, and/or an improvement and more extensive regulation regarding the paper technical properties of fibers as compared to blade refining without a pretreatment. In some cases, compression refining alone without blade refining can be an adequate treatment. The saving in energy consumption achieved with a method according to the embodiments is remarkable because, in compression refining, the number of impacts received by a fiber material is fewer but the force of individual impacts is substantially greater when compared with traditional blade refining. Thus, for example the number of plastic deformations with respect to elastic ones increases, thus reducing the amount of energy needed for modification. In addition, the migration of a refining-bound material through the vibrating crusher requires very little energy and may occur for example by the action of gravity. With the production outputs of a paper and/or pulp mill, this provides a sub- stantial energy saving in pumping costs.

Brief description of the figures

The detailed description of the figures relates more specifically to exemplary embodiments of the invention with reference to the accompanying figures, in which fig. 1 shows a flowchart for a fiber material processing method, figs. 2a-2d show the principle of compression refining and its effect on the properties of a fiber material, and

fig. 3 shows the functional units of a vibrating crusher implementing the method. Detailed description of the figures

Fig. 1 shows a method 100 for processing a fiber material, for example wood chips or wood pulp, i.e. cellulose pulp, used in the manufacture of a fibrous product, for example paper or board, in such a way that the fiber material is refined for promoting its pulping and/or chemical treatment. Starting step 102 comprises providing a raw material for wood pulp, activating machines and equipment needed for producing, treating, and moving the wood pulp.

By using for example birch, spruce, or pine as the raw material, step 110 comprises the production of wood chips or wood pulp, comprising wood fibers which are individual or in contact with each other.

In the event of being so-called undried pipe pulp, the produced wood pulp is conveyed by pumping in step 20 for example along a purpose-built piping to a paper and/or pulp mill, directly into a refiner tank, to wait for refining. Alternatively, in case the produced wood pulp is dried into bale pulp for transport and/or storage, the dried bale pulp will be transported to a paper and board mill, wherein a pulper is used for breaking up the wood pulp bales by means of water for pulp stock of uniform consistency which can be pumped along the mill's pipe systems into the refiner tank.

In step 130, the refining of wood pulp is implemented as compression refining, which is conducted by using at least one appropriate vibrating crusher integrated as part of the mill's pulp processing line. Figs. 2a and 2b show the principle of compression refining, which can be used as the only refining for fiber material or it can be optionally conducted as a pre- treatment in advance of traditional blade refining. In compression refining, a fiber material 250 is compressed, as shown in fig. 2a, between two cylindrical surfaces with an appropriate vibrating crusher 200, wherein the fiber material arriving by way of an inlet opening 210 is compressed between internal walls 222a, 222b of a crushing chamber 220 and a crushing cone or crusher 230 moving in the crushing chamber 220, whereby wood fibers 250 employed as the fiber material are subjected primarily to compressive forces as indicated by arrows present in the cross-section of the left-side and middlemost fibers in fig. 2b. In a longitudinal view 260 from a point B in the middlemost fiber 250 of fig. 2b, there is depicted a fiber structure in which hemicellulose 262 is present in the cell wall between microfibrils 264 and provides an adhesive type reinforcement for the structure between the fibrils 264. The purpose of compression refining in fiber modification is specifically to disrupt cross-links 266 formed by the hemicellulose 262. The compression-treated fiber material discharges from the crushing chamber 220 by way of outlet openings 240a, 240b.

In the context of fiber modification, the purpose of compression refining is to increase intra-fiber fibrillation and modifiability, making the fibers, among other things, more capable of taking up the mechanical stress of blade refining. In traditional blade refining occur several different phenomena, such as straightening of the fiber, intra- and extra-fiber fibrillation, fiber breaks, as well as formation of fines. These phenomena can only be influenced in a limited degree by changing the refining conditions. Compression refining also experiences above-mentioned phenomena, but in a different proportion such that internal fibrillation is dominating. In many cases, internal fibrillation has been presumed to be a highly beneficial phenomenon from the standpoint of improving quality characteristics, mainly the strength, of a fiber material, for example wood pulp. In addition, the compression-treated fiber, for example wood fiber, is mot pliable and thereby the fiber may behave differently in the blade refining process, for example there may be a decrease in wood fiber breaks and the formation of fines.

Fig. 2c presents the effect of compression treatment, conducted as a pretreatment, on the tensile strength of paper manufactured from chemical wood pulp at various pulp filtration rates (Schopper-Riegler or SR-number). It is noted from the figure that, with a suitable pretreatment, it is possible to achieve a considerably higher tensile strength at a constant filtration rate.

Fig. 2d presents the effect of compression treatment on the width of a wood fiber, which reflects the wood fiber swelling caused by internal fibrillation. Compression refining is also capable of promoting the penetration of process chemicals into fiber material.

In the event that it is desirable in step 132 to subject the vibration-refined wood pulp to a repeated vibrating crusher treatment, the method returns to compression refining step 130. In the event that the degree of compression refining is sufficient, the method proceeds to step 38. If it is desirable in step 138 to subject the compression-refined wood pulp to a further processing, it can be further subjected to blade refining and/or a chemical treatment in step 140, in which case the compression refining functions as a pretreatment for blade refining and/or a chemical treatment. It is also a possible option that the chemical treatment of wood pulp be conducted during the course of compression refining.

In case the refining of wood pulp comprises just vibrating crusher refining, the method proceeds directly to step 150.

In step 150, following the blade refining or alternatively the compression refining, the refined wood pulp is passed by pumping along appropriate pipe sys- terns, or in dried condition, to a paper or board machine for producing paper, board or other fibrous products therefrom.

In step 152, the method for processing wood pulp comes to an end. Fig. 3 presents in cross-section a KID 300K vibrating crusher 300 used for the crushing of minerals and suitable for the compression treatment of fiber material.

The KID machine 300 can be used for refining fiber material, and it achieves refining such as obtained by blade refiners intended for fiber material. It was found out in the tests that the fiber material refining conducted with this machine 300, in order to attain various properties, can be supplemented with traditional fiber material refining equipment. As a final result, this enables on the one hand an improved quality level of fiber material and on the other hand a reduced consumption of refining energy.

The vibrating crusher 300 comprises for example an adjustment collar 302, a crushing chamber (compression zone) 320 and its internal wall 322, a crushing cone (crusher) 330, a vibration generator 304, a drive block 306, a frame support 308, 342, a conical support 312, reinforcement ring 314, ball support 316, a frame 318, a shock absorber 324, a cup 326, a cover 328, feed elements 310 comprising an inlet opening (reception opening, feeding zone), a guard 332, a bearing assembly 334, one or more fastening bolts 336, a fitting for lubrication feed 338, one or more fittings for draining 342a, 342b, and discharge elements 340 comprising an outlet opening.

The fiber material is delivered into the machine by way of the inlet opening 310 and it proceeds through the machine 300 by the action of gravity or a pressure difference while being refined. The fiber material becomes compressed between the crushing chamber 320 and the wall 322 and discharges from a bottom part of the machine 300 by means of the discharge element 340. The freeness of fiber material to be treated is adjusted to a desired level prior to the treatment. In addition, the number and force of impacts applied to fiber material, as well as the migration of fiber material across the compression zone (= production rate), can be influenced by at least one of the following factors: vibration frequency of the crushing cone 330, clearance between the cone 330 and the crushing chamber's wall 322, asymmetry of the eccentric weight, width of the refining zone, diameter of the cone 330, and number of treatment cycles. The above-mentioned factors, including freeness, must be optimized separately for attaining the fiber properties, energy consumption level, as well as production rate desired for various cases.

The conical section 3 0, 320, 322, i.e. the feeding and compression zone, can have various alternatives regarding its design. An alternative embodiment can be designed in such a way that the actual conical section 310, 320, 322 does not exist and/or especially the compression zone 320, 322 has been constructed in a cylindrical design. In this case, the width of the compression zone 320, 322 could be adjusted when operating the vibrating crusher 300 (on-line), although the adjustment of a clearance would become slightly more inconvenient. Alternatively, the compression zone 320, 322 can also be a very gently conical, whereby the narrowing of the compression zone 320, 322 would also lead to an increase of the clearance. The roughness and/or the contour, for example a corrugated contour, for a surface material of the cones 310, 320, 322 can also be used for influencing operation of the machine 300.

The foregoing are but a few exemplary embodiments of the invention. The principle according to the invention can naturally be varied within the scope of protection defined by the claims, regarding for example implementation details as well as fields of use.

Claims

1. A method (100) for processing a fiber material, comprising refining (130, 140) the fiber material, which is used in the manufacture of a fibrous product and which contains fibers, for promoting its pulping and/or chemical treatment, characterized in that the fiber material refining (130) is conducted as compression refining performed by using a vibrating crusher.

2. A method as set forth in claim 1 , wherein the fiber material comprises chips and/or fibers individual or in contact with others.

3. A method as set forth in either of the preceding claims, further comprising refining (140) the vibrating crusher-refined fiber material with a blade refiner and/or treating the refined fiber material chemically (140) prior to conveying (150) the fiber material to the manufacture of a fibrous product.

4. A vibrating crusher (300), which is adapted to implement the method of claim 1 or 2.

5. Use of a vibrating crusher for processing a fiber material, said vibrating crusher being used for refining by compression the fiber material, which is used in the manufacture of a fibrous product and which contains fibers, for promoting its pulping and/or chemical treatment.

6. Use of a vibrating crusher as set forth in claim 5, wherein the fiber mate- rial comprises chips and/or fibers individual or in contact with others.