A refining plate and a method of pulping a wood processing by-product

Abstract

The application discloses a refining plate and a method for pulping wood processing by-products. The refining plate comprises a plate base, a defibration zone and a beating zone arranged on the plate base. The beating zone comprises a plurality of wedge-shaped teeth arranged at intervals, and a groove is formed between two adjacent teeth. The bottom surface of the groove is a first flow guide slope surface gradually rising from front to back. The rear end of the first flow guide slope surface forms a first limiting step with the surface of the plate base. The method for pulping wood processing by-products comprises collecting, slicing, screening and cleaning, pre-cooking and refining. The refining is performed by the above-mentioned refining plate. The pulp is rubbed between the interlaced teeth. Compared with the secondary wood pulp obtained by the traditional refining plate, the beating degree of the secondary wood pulp is increased by 2-3°SR, the wet weight is increased by 2-3g, and the beating degree can reach 14-16°SR.

Description

Technical Field

[0001] This invention relates to the technical field of papermaking, and more particularly to a pulping method for a pulping mill and a wood processing by-product. Background Technology

[0002] Wood is a valuable renewable resource. However, many wood processing byproducts are often discarded or burned as firewood, which not only fails to generate significant economic benefits but also increases carbon emissions and pollutes the environment. The pulp and paper industry requires a large amount of wood resources as raw materials. Therefore, making full use of wood processing byproducts is a possibility. However, conventional high-consistency grinding discs used to process these wood processing byproducts generally produce secondary wood pulp with a low degree of freeness. For example, a pulping grinding disc disclosed in patent number CN202222849084.9, when used to pulp wood processing byproducts, typically produces secondary wood pulp with a freeness of around 13°SR, which is difficult to further improve. In papermaking, the freeness of secondary wood pulp needs to be increased to a certain value before it can be used for papermaking. However, the secondary wood pulp produced by traditional pulping discs has a low freeness, requiring a large amount of electricity to increase the freeness to the required value. Therefore, it consumes too much energy and is not environmentally friendly. Furthermore, paper made from secondary wood pulp with a freeness of 13°SR has low durability and strength. Therefore, there is an urgent need for a new tooth profile to address the above problems. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide a pulping disc that can improve the beating degree and efficiency of secondary wood pulp, and a pulping method for a wood processing by-product using the pulping disc.

[0004] The technical solution adopted by this invention to solve its technical problem is as follows:

[0005] A pulping disc includes a disc substrate. The disc substrate includes a dissolving zone and a pulping zone arranged sequentially from a pulp inlet end to a pulp outlet end. The pulping zone includes several sets of grinding teeth arranged at intervals from front to back in an arc shape. Each grinding tooth set includes several wedge-shaped grinding teeth arranged at intervals, and a grinding groove is formed between two adjacent grinding teeth. A heat dissipation groove is provided on the side of the grinding teeth. When pulping is performed by two mating discs, the grinding teeth on the two discs are interlaced to form a pulping gap for pulp flow. The bottom surface of the grinding groove is a first guiding slope that gradually rises from front to back. The rear end of the first guiding slope forms a first limiting step with the surface of the disc substrate, so that the pulp flows along the direction of the pulping gap and the flow rate of the pulp is slowed down when it is kneaded between the interlaced grinding teeth on the two discs.

[0006] In a preferred embodiment of the present invention, the angle formed between the first guide slope and the surface of the grinding disc substrate is z, and z is 6°-10°.

[0007] In a preferred embodiment of the present invention, the grinding gear group includes a plurality of first grinding gear groups and a second grinding gear group disposed on the rear side of the first grinding gear group. The first grinding gear group includes a plurality of first grinding teeth, and the second grinding gear group includes a plurality of second grinding teeth.

[0008] In a preferred embodiment of the invention, the second grinding tooth is lower in height than the first grinding tooth.

[0009] In a preferred embodiment of the present invention, the heat dissipation grooves are distributed on the front and rear sides of the grinding teeth.

[0010] In a preferred embodiment of the present invention, the angle formed between the front side of the grinding tooth and the surface of the grinding disc substrate is α, and the angle formed between the rear side of the grinding tooth and the surface of the grinding disc substrate is β, and α = β.

[0011] In a preferred embodiment of the present invention, the scavenging zone includes a plurality of racks and a scavenging tooth assembly connected to the rear end of the racks and arranged in an arc shape, and the height of the surface of the scavenging zone gradually increases from front to back.

[0012] In a preferred embodiment of the present invention, the scavenging tooth assembly includes a plurality of wedge-shaped scavenging teeth spaced apart, and a scavenging tooth groove is formed between two adjacent wedge-shaped scavenging teeth. The bottom surface of the scavenging tooth groove is a second guide slope that gradually rises from front to back, and the rear end of the second guide slope forms a second limiting step with the surface of the grinding disc substrate.

[0013] In a preferred embodiment of the invention, one of the at least two slitting teeth is connected to a rack.

[0014] This invention also discloses a method for pulping wood processing by-products, the steps of which are as follows:

[0015] ①: Collect and store wood processing by-products;

[0016] ②: Slice the stored wood processing by-products to form thin sheets that can be used for pulping;

[0017] ③: The thin slices are screened and cleaned to remove impurities mixed in with them;

[0018] ④: The thin slices that have been screened and washed are pre-cooked to soften the fibers inside;

[0019] ⑤: The precooked sheets are conveyed to a pulper for pulping; the pulper uses a pulping disc as described above. During pulping, the pulp flows from the inlet end into the decomposition zone and then into the beating zone, and finally flows out from the outlet end to produce secondary wood pulp.

[0020] The beneficial effects of this invention are as follows: The pulping disc includes a disc substrate and a dissolving zone and a beating zone disposed on the disc substrate. The beating zone includes a set of grinding teeth, wherein the grinding teeth set includes a plurality of wedge-shaped grinding teeth arranged at intervals, and a grinding groove is formed between two adjacent grinding teeth. At the same time, the bottom surface of the grinding groove is a first guide slope that gradually rises from front to back, and the rear end of the first guide slope forms a first limiting step with the surface of the disc substrate. In this way, by using this pulping disc to beate wood processing by-products as raw materials for pulp, the pulp is kneaded between the interlaced grinding teeth. Compared with secondary wood pulp produced by pulping with conventional discs, the freeness is increased by 2°SR-3°SR, and the wet weight is increased by 2-3g, so that the freeness can reach 14°SR-16°SR. Thus, under the same power conditions, the energy consumption per ton of pulp for papermaking using secondary wood pulp formed by pulping wood processing by-products with this disc will be reduced by 15%-20%. Furthermore, the grinding teeth are equipped with heat dissipation grooves on their sides to increase the heat dissipation area and reduce energy consumption. At the same time, the number of grinding edges can be increased to improve pulping efficiency. Attached Figure Description

[0021] Figure 1 This is a three-dimensional schematic diagram of a grinding disc according to the present invention;

[0022] Figure 2 This is a top view of a grinding disc according to the present invention;

[0023] Figure 3 This is a cross-sectional view of a grinding disc according to the present invention;

[0024] Figure 4 This invention relates to a grinding wheel for grinding slurries. Figure 3 Enlarged view of Figure A;

[0025] Figure 5 This invention relates to a grinding wheel for grinding slurries. Figure 3 Enlarged view of Figure B;

[0026] Figure 6 This is a schematic diagram of two grinding discs cooperating in a grinding disc according to the present invention;

[0027] Figure 7 This is a schematic flowchart of a method for pulping a wood processing by-product according to the present invention. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will now be clearly and completely described in conjunction with the accompanying drawings.

[0029] Reference Figures 1 to 6 A pulping disc includes a disc substrate 1. The disc substrate 1 includes a dispersing zone 2 and a pulping zone 3 arranged sequentially from a pulp inlet end to a pulp outlet end. The pulping zone 3 includes several sets of grinding teeth 31 arranged at intervals from front to back in an arc shape. Each grinding tooth 31 includes several wedge-shaped grinding teeth 311 arranged at intervals, and a grinding groove 312 is formed between two adjacent grinding teeth 311. A heat dissipation groove 4 is provided on the side of the grinding teeth 311 to increase the heat dissipation area and reduce energy consumption. Furthermore, when pulping is performed by two mating pulping discs, the grinding teeth 31 on the two pulping discs are staggered to form a pulping gap 5 for pulp flow, and the bottom of the grinding groove 312... The surface is a first guiding slope 313 that gradually rises from front to back, wherein the rear end of the first guiding slope 313 forms a first limiting step 314 with the surface of the grinding disc substrate 1; raising the first guiding slope 313 can guide the flow direction of the slurry, so that it flows along the direction of the grinding gap 5, and at the same time can slow down the flow rate of the slurry when it is kneaded between the intersecting grinding teeth 311 on the two grinding discs, that is, it can make the slurry fully kneaded between the corresponding grinding edges of the intersecting grinding teeth 311 (the rear grinding edge of the front grinding tooth 311 and the front grinding edge of the rear grinding tooth 311), and the first limiting step 314 formed can prevent the slurry from flowing back, thereby improving the grinding efficiency. Because the grinding teeth 311 on the grinding disc substrate 1 are wedge-shaped, this grinding disc is used to pulp wood processing by-products as raw materials for pulp. The pulp is kneaded between the interlaced grinding teeth 311. Compared with the traditional grinding disc method (which forms a uniform pad on the grinding disc to make the pulp rub against each other), this method can more effectively retain the fiber length of the pulp. Moreover, compared with the secondary wood pulp produced by grinding with traditional grinding discs, the freeness can be increased by 2°SR-3°SR, and the wet weight can also be increased by 2-3g, so that the freeness can reach 14°SR-16°SR. Thus, under the same power conditions, the energy consumption per ton of pulp for papermaking using secondary wood pulp formed by grinding wood processing by-products with this grinding disc will be reduced by 15%-20%.

[0030] Specifically, the angle between the first guide slope 313 and the surface of the grinding plate substrate 1 is z, and z is 6°-10°, so as to avoid the first guide slope 313 being too steep and thus having a large impact on the flow speed of the slurry in the grinding gap 5.

[0031] In this scheme, the grinding gear assembly 31 includes several sets of first grinding gear assemblies 32 and a second grinding gear assembly 33 disposed behind the first grinding gear assemblies 32. The first grinding gear assembly 32 includes several first grinding teeth 321, and the second grinding gear assembly 33 includes several second grinding teeth 331. Further, referring to... Figure 6The second grinding tooth 331 is lower in height than the first grinding tooth 321, thereby reducing the vertical difference of the grinding gap 5 formed by the interlacing of the second grinding teeth 331 at the pulp outlet end, which facilitates pulp flow and improves pulp discharge efficiency.

[0032] In this solution, the heat dissipation grooves 4 are distributed on the front and rear sides of the grinding teeth 311. In this way, when the slurry is ground by the grinding teeth 311, its friction and the number of grinding edges can be increased to improve the grinding efficiency. It can also increase the heat dissipation area and reduce energy consumption, while avoiding the slurry from losing its potential.

[0033] In this design, the angle between the front side of the grinding tooth 311 and the surface of the grinding plate substrate 1 is α, and the angle between the rear side of the grinding tooth 311 and the surface of the grinding plate substrate 1 is β, where α = β. This allows the grinding tooth 311 to grind the slurry evenly in all directions, resulting in more uniform slurry mixing. Furthermore, the grinding tooth 311 is symmetrical, and the axes of symmetry of the front and rear grinding teeth 311 are not on the same straight line. Simultaneously, the width of the front side of the grinding tooth 311 is greater than the width of the rear side, creating a guide slope that is narrower at the front and wider at the back. After the slurry passes over the guide slope, it disperses and flows to the next grinding tooth 311 for mixing, ensuring uniform slurry mixing.

[0034] In this scheme, the slurry-removing zone 2 includes several racks 21 and a slurry-removing tooth assembly 22 connected to the rear end of the racks 21 and arranged in an arc shape. The height of the surface of the slurry-removing zone 2 gradually increases from front to back, thereby facilitating the entry of slurry into the slurry-removing zone 2 for pulping. Specifically, the slurry-removing tooth assembly 22 includes several wedge-shaped slurry-removing teeth 221 arranged at intervals, and a slurry-removing tooth groove 222 is formed between two adjacent wedge-shaped slurry-removing teeth 221. The bottom surface of the slurry-removing tooth groove 222 is a second guide slope 223 that gradually rises from front to back, so that the rear end of the second guide slope 223 forms a second limiting step 224 with the surface of the grinding plate substrate 1. The width of the slurry-removing teeth 221 is larger than the width of the grinding teeth 311, thereby preventing slurry backflow. The slurry-removing teeth 221 can fully slurry-removing, thereby preventing the grinding teeth 311 from wearing out too quickly. In this case, at least one of the two slitting teeth 221 is connected to a rack 21.

[0035] Reference Figure 7 The present invention also provides a method for pulping wood processing by-products, the pulping method comprising the following steps:

[0036] ①: Collect and store wood processing byproducts using a collection device;

[0037] ②: The wood processing by-products stored in the collection device are sliced ​​using a slicing device to form thin sheets that can be used for pulping;

[0038] ③: The formed thin film is screened and cleaned by a screening and washing device to remove impurities mixed in with it;

[0039] ④: The screened and cleaned flakes are sent to the reactor for pre-cooking to soften the fibers inside;

[0040] ⑤: The pre-cooked sheets are conveyed to a pulper for pulping. The pulper uses the pulping discs described above. During pulping, the pulp flows from the inlet end into the loosening zone 2, then into the beating zone 3, and finally out from the outlet end. The secondary wood pulp produced by pulping wood processing by-products through this pulper can achieve a freeness of 14°.

[0041] SR-16°SR reduces the energy required for papermaking from this secondary wood pulp, thereby lowering production costs.

[0042] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A pulping disc, comprising a disc substrate (1), wherein the disc substrate (1) includes a disintegration zone (2) and a pulping zone (3) sequentially arranged from a pulp inlet end at the front end to a pulp outlet end at the rear end, characterized in that, The pulping zone (3) includes several sets of grinding teeth (31) arranged in an arc shape and spaced from front to back. Each grinding tooth (31) has several grinding teeth (311) arranged at intervals. Each grinding tooth (311) is a wedge-shaped grinding tooth, and a grinding groove (312) is formed between two adjacent grinding teeth (311). The sides of each grinding tooth (311) are provided with heat dissipation grooves (4). The heat dissipation grooves (4) are distributed on the front and rear sides of the grinding teeth (311). When pulping is performed by two mating grinding discs, the grinding teeth (31) on the two grinding discs are staggered to form a pulping gap (5) that allows the pulp to flow. The grinding groove (312) The bottom surface is a first guide slope (313) that gradually rises from front to back. The rear end of the first guide slope (313) forms a first limiting step (314) with the surface of the grinding disc substrate (1) so that the slurry flows along the direction of the grinding gap (5) and can slow down the flow rate of the slurry when it is rubbed between the intersecting grinding teeth (311) on the two grinding discs. The grinding teeth (311) are symmetrical from left to right, and the axes of symmetry of the grinding teeth (311) on the front side and the grinding teeth (311) on the rear side are not on the same straight line. At the same time, the width of the front side of the grinding teeth (311) is larger than the width of the rear side of the grinding teeth (311), so that the guide slope formed is narrower at the front and wider at the back.

2. The grinding slurry / grinding disc according to claim 1, characterized in that, The angle between the first guide slope (313) and the surface of the grinding plate substrate (1) is z, and z is 6°-10°.

3. The grinding slurry / grinding disc according to claim 1, characterized in that, The grinding gear group (31) includes several groups of first grinding gear groups (32) and a second grinding gear group (33) disposed on the rear side of the first grinding gear group (32). The first grinding gear group (32) includes several first grinding teeth (321), and the second grinding gear group (33) includes several second grinding teeth (331).

4. A grinding slurry / grinding disc according to claim 3, characterized in that, The second grinding tooth (331) is lower in height than the first grinding tooth (321).

5. A grinding slurry / grinding disc according to claim 1, characterized in that, The angle between the front side of the grinding tooth (311) and the surface of the grinding plate substrate (1) is α, and the angle between the rear side of the grinding tooth (311) and the surface of the grinding plate substrate (1) is β, and α=β.

6. A grinding slurry / grinding disc according to any one of claims 1 to 5, characterized in that, The scavenging zone (2) includes several racks (21) and a scavenging tooth group (22) connected to the rear end of the racks (21) and arranged in an arc shape. The height of the surface of the scavenging zone (2) gradually increases from front to back.

7. A grinding slurry / grinding disc according to claim 6, characterized in that, The scraping tooth assembly (22) includes a number of wedge-shaped scraping teeth (221) spaced apart. A scraping tooth groove (222) is formed between two adjacent wedge-shaped scraping teeth (221). The bottom surface of the scraping tooth groove (222) is a second guide slope (223) that gradually rises from front to back. The rear end of the second guide slope (223) forms a second limiting step (224) with the surface of the grinding disc substrate (1).

8. A grinding slurry and grinding disc according to claim 7, characterized in that, One of the at least two slitting teeth (221) is connected to a rack (21).

9. A method for pulping a wood processing by-product, characterized in that, The pulping method steps are as follows: ①: Collect and store wood processing by-products; ②: Slice the stored wood processing by-products to form thin sheets for pulping; ③: The thin slices are screened and cleaned to remove impurities mixed in with them; ④: The thin slices that have been screened and washed are pre-cooked to soften the fibers inside; ⑤: The precooked sheets are conveyed to a pulper for pulping; the pulper uses a pulping disc as described in any one of claims 1 to 8. During pulping, the pulp flows from the inlet end into the disintegration zone (2) and then into the pulping zone (3), and finally flows out from the outlet end to produce secondary wood pulp.

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