Screen press filter wet pulp machine and pulp distribution device thereof

Abstract

The utility model provides a net pressure filtration wet pulp machine and a pulp distribution device thereof. The pulp distribution device comprises a bracket, a pulp inlet box and a pulp inlet pipe, the slurry inlet box is fixedly connected with the support, the slurry inlet box is of a wedge-shaped structure, the thickness of the small end of the wedge-shaped structure is larger than that of the large end of the wedge-shaped structure, the large end is used for being communicated with a slurry pressing device of the net pressure filtration wet slurry machine, and a flow guide plate extending towards the large end along the small end is arranged in the slurry inlet box. The pulp inlet pipe is communicated with the small end of the pulp inlet box and used for conveying paper pulp to the pulp inlet box, and the paper pulp flows through the pulp inlet box and flows into a pulp pressing device of the net filter pressing wet pulp machine through the large end. According to the pulp distribution device of the net pressure filtration wet pulp machine, the flow guide plate structure is arranged in the pulp inlet box, it can be guaranteed that pulp is evenly distributed, transverse flowing is reduced, then the flow direction of the pulp is optimized, turbulent flow is restrained, the uniformity of pulp distribution is improved, the problem of pulp overflowing is solved, and the service life of the dewatering net is effectively prolonged.

Description

Technical Field

[0001] This application relates to the technical field of papermaking equipment, specifically to a wire press wet pulping machine and its pulp distribution device. Background Technology

[0002] The dewatering process of a double-net filter press wet slurry machine begins with a slurry pump delivering the slurry to the slurry distribution device. After being evenly dispersed within the device, the slurry flows out from the outlet and enters the pressing device. The wet slurry, after dewatering in the pressing device, is then separated by a scraper and enters the downstream flash drying process. However, in conventional technical solutions, the slurry distribution device of the double-net filter press wet slurry machine exhibits poor uniformity in slurry distribution, severely limiting the overall dewatering efficiency of the machine. Utility Model Content

[0003] The first aspect of this application provides a slurry distribution device for a mesh pressure wet slurry filter press, the slurry distribution device comprising:

[0004] support;

[0005] The slurry inlet box is fixedly connected to the bracket. The slurry inlet box has a wedge-shaped structure, with the thickness of the small end of the wedge structure being greater than the thickness of the large end. The large end is used to communicate with the slurry pressing device of the mesh press wet slurry machine. The slurry inlet box is provided with a guide plate extending from the small end toward the large end.

[0006] The pulp inlet pipe is connected to the small end of the pulp inlet box and is used to deliver pulp to the pulp inlet box. The pulp flows through the pulp inlet box and into the pressing device of the wire press filter press through the large end.

[0007] In some alternative embodiments, there are multiple guide vanes, and the multiple guide vanes have a wedge-shaped opening structure between them.

[0008] In some alternative embodiments, the deflector is made of 316L stainless steel.

[0009] In some alternative embodiments, the support includes a support beam and a first support vertical beam and a second support vertical beam connected to both ends of the support beam, and the slurry inlet box is fixedly connected to the support beam.

[0010] In some optional embodiments, the support further includes a load-bearing beam, the two ends of which are respectively connected to the first support vertical beam and the second support vertical beam, and the support horizontal beam and the load-bearing beam are respectively fixedly connected to opposite sides of the slurry inlet box.

[0011] In some optional embodiments, the load-bearing beam is a closed square steel structure; the material of the load-bearing beam is 316L stainless steel.

[0012] In some optional embodiments, the grout box includes a first grout box and a second grout box arranged side by side, with a hoisting anchor beam between the first grout box and the second grout box.

[0013] In some alternative embodiments, the small end of the slurry inlet box is provided with an opening, and the opening is provided with a cover plate that can open or seal the opening.

[0014] In some optional embodiments, the slurry distribution device further includes a baffle plate disposed at the bottom of the slurry inlet box, the baffle plate being inclined relative to the horizontal plane.

[0015] Secondly, this application provides a mesh-pressed wet slurry filter, which includes a slurry pressing device and the slurry distribution device described in the above embodiments.

[0016] The slurry distribution device of the mesh pressure wet slurry filter provided in this application embodiment can ensure uniform slurry distribution and reduce lateral flow by setting a guide plate structure in the slurry inlet box, thereby optimizing the slurry flow direction, suppressing turbulence formation, improving the uniformity of slurry distribution, solving the problem of slurry overflow, and effectively extending the service life of the dewatering mesh. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the wet slurry filter press of this application;

[0019] Figure 2 This is a schematic diagram of the structure of an embodiment of the pulping device of this application;

[0020] Figure 3 yes Figure 2 A schematic diagram of the pulping device from another perspective in the embodiment;

[0021] Figure 4 yes Figure 2 A schematic diagram of the internal structure of the slurry distribution device in the embodiment. Detailed Implementation

[0022] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the application. Similarly, the following embodiments are only some, not all, embodiments of the present application, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present application.

[0023] The terms "first," "second," and "third" used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movement of components in a specific posture (as shown in the figures). If the specific posture changes, the directional indication will also change accordingly. The terms "comprising" and "having," and any variations thereof, in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or components inherent to these processes, methods, products, or devices.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] First, this application provides a mesh-press wet slurry filter, specifically a double-mesh-press wet slurry filter. Please refer to [link to relevant documentation]. Figure 1 , Figure 1 This is a schematic diagram of the overall structure of an embodiment of the mesh press wet slurry machine of this application. The (double) mesh press wet slurry machine includes two parts: a slurry distribution device 10 and a slurry pressing device 20.

[0026] Specifically, the pulp first enters the pulp distribution device 10 (as shown by the arrow in the figure), where it is evenly dispersed before flowing out from the outlet and into the pressing device 20. It then covers the filter screen surface of the pressing device 20 and is held between two layers of high-strength polyester filter screens before entering a multi-stage pressing zone consisting of a wedge-shaped dewatering zone and six pressing rollers. The initial wet pulp concentration of 5.5%–6.5% first passes through a wedge-shaped zone that gradually narrows from 7cm to 4cm, where it undergoes pre-dewatering under gravity to form a stable pulp layer; subsequently, it enters the pressing stage: the first two pairs of... Small-diameter pressure rollers (first and second pressure zones) gently remove surface moisture, protecting the fiber structure; the third pressure zone... The drive rollers maintain stable operation of the filter screen while improving dewatering efficiency; the subsequent two pairs Pressure rollers (four-pressure and five-pressure zones) and end The large-diameter drive rollers (six-pressure zone) constitute the main pressure zone, achieving deep dewatering through progressive pressurization and roller surface squeezing and shearing, ultimately resulting in a wet pulp dryness of 45%. During operation, the three-pressure and six-pressure dual-drive rollers are precisely adjusted by a variable frequency motor to ensure synchronous and stable operation of the filter screen; the pressed water is recycled through a collection tank, and the dewatered wet pulp is peeled off by a scraper and enters the downstream flash drying process. Detailed structure of the slurry pressing device 20 is readily understood by those skilled in the art and will not be elaborated upon here.

[0027] Please refer to the following: Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the structure of an embodiment of the pulping device of this application. Figure 3 yes Figure 2 A schematic diagram of the slurry distribution device from another perspective in this embodiment. The slurry distribution device 10 in this embodiment includes a support 100, a slurry inlet box 200, and a slurry inlet pipe 300.

[0028] The pulp inlet box 200 is fixedly connected to the support 100. The pulp inlet box 200 has a wedge-shaped structure, with the thickness of the smaller end greater than the thickness of the larger end; that is, the smaller end of the pulp inlet box 200 is narrow and thick, while the larger end is wide and flat. The larger end is used to connect with the pressing device 20 of the wire press wet pulp machine, and the smaller end is connected with the pulp inlet pipe 300. The pulp inlet pipe 300 is used to deliver pulp to the pulp inlet box 200. The pulp flows through the pulp inlet box and into the pressing device 20 of the wire press wet pulp machine through the larger end. The larger end of the pulp inlet box 200 and the pressing device 20 can be connected by a buffer connecting plate 30. The buffer connecting plate 30 is made of a material with a certain degree of flexibility (such as PVC board or thin stainless steel plate), which can deform appropriately to buffer the impact force and flow rate of the pulp.

[0029] Please refer to the following: Figure 4 , Figure 4 yes Figure 2The internal structure of the slurry distribution device in this embodiment is shown in the schematic diagram. The slurry inlet tank 200 is equipped with a guide plate 210 extending from the smaller end towards the larger end. Optionally, there can be multiple guide plates 210, with wedge-shaped openings between them. The guide plates can be made of 316L stainless steel.

[0030] The conventional pulp distribution device lacks a guide plate, resulting in uncontrolled pulp fluid dynamics due to the complete absence of this internal structure. Specifically, the pulp, injected at high speed into the open chamber, immediately diffuses and forms intense free turbulence due to the lack of any guiding constraints. This disordered flow exhibits an irregular velocity distribution across the chamber's cross-section, with high velocity in the central region and low velocity at the edges. This leads to uneven pulp distribution on the mesh surface, completely random fiber orientation, and an inability to form an effective interwoven network. This directly obstructs the migration path of water molecules during dewatering, which is the core reason why the pulp dryness only reaches 41-42% instead of the industry standard of 45%. Furthermore, variations in pulp thickness create a wet edge effect, ultimately forming an overflow wet edge band exceeding 15cm beyond the mesh width. Continuous edge overflow not only causes excessive white water concentration, but the fallen slurry also forms unevenly thick scale layers on the dewatering screen and tension rollers, with a maximum scale thickness of up to 12mm. These flocculent, hardened slurry clumps rub against the screen surface, drastically reducing the lifespan of the polyester dewatering screen and triggering a vicious cycle: scale buildup → increased friction → screen misalignment → further exacerbating uneven slurry distribution. Therefore, in terms of the dewatering process of the double-screen filter press wet pulp mill, the lack of a guide plate design in the slurry distribution device results in disordered diffusion of turbulent slurry, uneven lateral distribution, severe wet edge overflow, and a significant increase in dewatering resistance. This directly leads to a slurry dryness lower than the industry standard and increased fiber loss. This structural defect has severely restricted the overall dewatering process efficiency.

[0031] To address the design flaws of existing dual-net filter press wet slurry distribution devices, the following improvements are implemented: A guide plate 210 made of corrosion-resistant and wear-resistant 316L stainless steel is installed inside the distribution device. This material effectively resists the erosion of chemicals in the chemimechanical slurry and withstands long-term slurry scouring. The guide plate is precisely positioned at a critical location in the inlet diffusion section of the distribution device. By optimizing the angle and arrangement of the guide plate, the flow velocity and direction of the slurry are altered, ensuring uniform slurry distribution and effectively suppressing lateral flow, thus eliminating free turbulence. The guide plate is fully welded to the upper and lower walls of the distribution device to ensure a complete seal. Simultaneously, the maximum inlet pressure is considered in the structural strength calculations to ensure that the flow guidance system does not deform under 2.5 times the working pressure. This completely resolves the process defects caused by disordered flow.

[0032] Alternatively, please continue reading Figures 2 to 4In this embodiment, the support frame 100 includes a supporting crossbeam 110 and a first supporting vertical beam 120 and a second supporting vertical beam 130 connected to both ends of the supporting crossbeam 110. The feed box 200 is fixedly connected to the supporting crossbeam 110. Optionally, the support frame 100 in this embodiment further includes a load-bearing beam 140, with both ends of the load-bearing beam 140 connected to the first supporting vertical beam 120 and the second supporting vertical beam 130, respectively. The supporting crossbeam 110 and the load-bearing beam 140 are fixedly connected to opposite sides of the feed box 200, providing fixation and load-bearing support for the feed box 200 from both sides.

[0033] Optionally, the load-bearing beam 140 in this embodiment is a closed square steel structure; the material of the load-bearing beam 140 is 316L stainless steel.

[0034] The conventional design for the slurry distribution device, which uses an upward-facing U-shaped carbon steel structure for support, has a serious design flaw. This material will undergo electrochemical corrosion when in prolonged contact with slurry and white water containing strong oxidizing chemicals such as NaOH and H2O2. The corrosion products will peel off layer by layer, eventually causing perforation of the support plate. This not only causes corroded iron filings to mix into the slurry and contaminate the product, but also leads to vibration and displacement of the slurry distribution device under the slurry inlet pressure due to the decrease in structural strength. At the same time, the open U-shaped cross-section design causes water and fibers released during the dewatering process to continuously accumulate in the tank, forming a vicious cycle of stagnant slurry and corrosive media, accelerating the corrosion process of the carbon steel support and seriously affecting the operational stability of the equipment. This material selection and structural design are completely unsuitable for the chemical mechanical slurry production conditions and represent a fundamental defect in the slurry distribution device process.

[0035] To address the structural defects of the existing slurry distribution device support in a double-mesh filter press, the following improvements were implemented: The original upward-facing U-shaped carbon steel support structure was completely replaced with a sealed square steel welded frame made of 316L stainless steel. By adopting this material with excellent corrosion resistance and a closed structural design, the electrochemical corrosion problem caused by the accumulation of slurry fibers and white water in the original U-shaped channel was completely resolved. The new square steel structure achieves complete sealing through a full-welding process, preventing any liquid and fiber residue. Simultaneously, the high chromium and nickel content of 316L stainless steel effectively resists strong oxidizing chemical media such as NaOH and H2O2. The improved support structure not only eliminates the risk of corrosion and iron filings contaminating the pulp, but its integrally welded square steel frame also has higher bending stiffness and torsional strength, which can fully withstand the pulp inlet pressure without vibration or displacement, thus ensuring the long-term stable operation of the pulp distribution device. This design fully considers the special requirements of the chemimechanical pulp pressing and dewatering process. Through material upgrades and structural optimization, it solves the fundamental problems of corrosion contamination, insufficient strength, and unstable operation in the original design, enabling the overall performance of the equipment to meet the standards of modern pulp dewatering processes.

[0036] Alternatively, please continue reading Figure 2 and Figure 4 In this embodiment, the slurry inlet box 200 includes a first slurry inlet box 201 and a second slurry inlet box 202 arranged side by side, and a hoisting anchor beam 203 is provided between the first slurry inlet box 201 and the second slurry inlet box 202. The first slurry inlet box 201 and the second slurry inlet box 202 have similar structures, and both are provided with guide plates inside. The small ends of the two are respectively connected to a slurry inlet pipe 300.

[0037] The slurry distribution device of the conventional double-net filter press wet slurry machine is seriously lacking in maintenance convenience considerations during design and manufacturing. Its structure does not have dedicated hoisting anchor points, which means that multiple hand-operated hoists must be used in conjunction with a crane for hoisting operations during equipment inspection and maintenance. This non-standard disassembly and assembly method is not only complicated to operate and poses safety hazards, but also greatly increases maintenance time and labor costs, fully exposing the major defects in the maintainability design of the device.

[0038] To address the design flaw of the existing double-net filter press wet slurry machine's slurry distribution device, which makes maintenance inconvenient, the following improvements were implemented: A high-strength stainless steel cross brace was added as a dedicated hoisting anchor point at the critical stress position between the two bell-shaped openings of the slurry distribution device. This cross brace (hoisting anchor beam 203) is made of 316 stainless steel and is firmly connected to the main structure through full welding. Its load-bearing capacity was rigorously calculated to ensure it could withstand the maximum hoisting load during maintenance. The improved design completely eliminates the non-standardized operation method that previously required the temporary use of multiple hand-operated hoists in conjunction with a crane. Operators can now complete the disassembly and assembly of the entire slurry distribution device simply by directly hoisting the cross brace using a crane. This improvement not only simplifies maintenance actions and shortens maintenance time, but more importantly, it completely eliminates the safety hazards present in the previously complex hoisting process. This structural improvement fundamentally solves the defects in the equipment's maintainability design, making daily maintenance work safer, faster, and more efficient, significantly reducing maintenance costs and downtime.

[0039] Please continue reading. Figure 4 In this embodiment, the small end of the pulp inlet box 200 is provided with an opening 2000, and the opening 2000 is provided with a cover plate 220. The cover plate 220 can open or seal the opening 2000. Specifically, the cover plate 220 can be connected to the small end of the pulp inlet box 200 by a structure such as screws or hinges. No specific limitation is made here. When the cover plate 220 is open, it is convenient to clean or maintain the inside of the pulp inlet box 200 through the small end.

[0040] Optionally, the slurry distribution device 10 in this embodiment also includes a slurry baffle 400, which is disposed at the bottom of the slurry inlet box 200. The slurry baffle 400 is inclined to the horizontal plane. The bottom of the slurry baffle 400 may be provided with a slurry recovery device (not shown in the figure) for recovering the slurry leaking from the slurry inlet box 200.

[0041] The pulp distribution device in this embodiment features a guide plate installed inside, made of 316L stainless steel, which is corrosion-resistant and wear-resistant. The guide plate is installed in the inlet diffuser section of the device to ensure uniform pulp distribution and reduce lateral flow. The guide plate is welded to the upper and lower walls of the distribution device to ensure sealing, optimize pulp flow direction, and suppress turbulence. The conventional U-shaped carbon steel lower support for the distribution device is replaced with 316L stainless steel, and the original U-shaped steel is replaced with welded square steel. No openings are left to prevent the accumulation of white water and pulp fibers. This corrosion resistance solves the problem of oxidation and corrosion by white water and pulp, avoiding insufficient strength after corrosion and iron filings contaminating the pulp, thus meeting the requirements of the chemimechanical pulp pressing and dewatering process. A 316L stainless steel cross brace is added between the two flared openings of the distribution device for hoisting, inspection, and maintenance operations, simplifying the previously complex work and saving time.

[0042] The pulping device in this embodiment has at least the following beneficial effects:

[0043] 1. By optimizing the arrangement of 316L stainless steel guide plates inside the pulp distribution device, the flow guiding system makes the fiber arrangement more orderly, improves the uniformity of pulp distribution, and significantly narrows the wet edge range of the pulp width from 15 cm to 5 cm. The problem of pulp overflow is completely solved, the hygiene of the equipment is improved, the service life of the dewatering screen is effectively extended, and the screen replacement cost is reduced. At the same time, the white water concentration is reduced, reducing pulp fiber loss. The pulp dryness has increased from the original 41-42% and stabilized at over 44%, approaching the industry advanced level of 45%. The improvement in pulp dryness directly reduces the energy consumption burden of subsequent processes. At the same time, it extends the service life of the dewatering screen and significantly reduces the replacement cost of the dewatering screen.

[0044] 2. By replacing the U-shaped carbon steel support of the pulp distribution device with a 316L stainless steel enclosed square steel structure, the original design defects were effectively resolved. The new structure completely eliminates the accumulation of pulp and white water, fundamentally eliminating the source of electrochemical corrosion. The excellent corrosion resistance of 316L stainless steel ensures the long-term stable operation of the support structure and avoids the generation of corrosive iron filings that contaminate the pulp. The integrally welded square steel frame significantly enhances the structural strength, effectively resists the pulp inlet pressure, and eliminates vibration and misalignment problems. The improved design is fully adapted to the special requirements of the chemical mechanical pulp pressing and dewatering process, making the equipment operation more reliable and stable, and greatly improving production quality and process efficiency.

[0045] 3. By adding a 316 stainless steel special hoisting cross brace between the two flared ends of the slurry distribution device, the standardized hoisting design greatly improves maintenance efficiency, simplifies the operation process, and effectively eliminates safety hazards; the use of corrosion-resistant 316 stainless steel extends the service life; the improved design shortens maintenance time, reduces maintenance costs, and makes the equipment operation more stable and reliable, fundamentally solving the core problem of difficult maintenance in the original design.

[0046] Based on the above three improvements, calculations show that the steam consumption per unit of flash drying is significantly reduced. Calculated based on an annual production of 270,000 tons of oven-dried pulp, the annual steam cost savings are as high as 1.05 million yuan. At the same time, the annual value of recyclable fibers exceeds 80,000 yuan, resulting in considerable economic benefits. The annual savings in steam and pulp loss costs exceed 1.13 million yuan.

[0047] The above description is only a part of the embodiments of this application and does not limit the scope of protection of this application. Any equivalent device or equivalent process transformation made based on the content of this application specification and drawings, or direct or indirect application in other related technical fields, are similarly included in the patent protection scope of this application.

Claims

1. A pulp distribution device for a mesh pressure filter wet pulp machine, characterized in that, The sizing device includes: support; The slurry inlet box is fixedly connected to the bracket. The slurry inlet box has a wedge-shaped structure, with the thickness of the small end of the wedge structure being greater than the thickness of the large end. The large end is used to communicate with the slurry pressing device of the mesh press wet slurry machine. The slurry inlet box is provided with a guide plate extending from the small end toward the large end. The pulp inlet pipe is connected to the small end of the pulp inlet box and is used to deliver pulp to the pulp inlet box. The pulp flows through the pulp inlet box and into the pressing device of the wire press filter press through the large end.

2. The slurry application device according to claim 1, characterized in that, The guide vanes are multiple in number, and the multiple guide vanes have a wedge-shaped opening structure between each other.

3. The slurry application device according to claim 2, characterized in that, The guide plate is made of 316L stainless steel.

4. The slurry application device according to claim 1, characterized in that, The support frame includes a support beam and a first support vertical beam and a second support vertical beam connected to both ends of the support beam. The slurry inlet box is fixedly connected to the support beam.

5. The slurry application device according to claim 4, characterized in that, The support also includes a load-bearing beam, the two ends of which are connected to the first support vertical beam and the second support vertical beam, respectively. The support horizontal beam and the load-bearing beam are fixedly connected to opposite sides of the slurry inlet box.

6. The slurry application device according to claim 5, characterized in that, The load-bearing beam is a closed square steel structure; the material of the load-bearing beam is 316L stainless steel.

7. The sizing device according to claim 1, characterized in that, The grouting box includes a first grouting box and a second grouting box arranged in parallel, and a hoisting anchor beam is provided between the first grouting box and the second grouting box.

8. The slurry application device according to claim 1, characterized in that, The small end of the slurry inlet box is provided with an opening, and the opening is provided with a cover plate, which can open or seal the opening.

9. The sizing device according to claim 1, characterized in that, The slurry distribution device also includes a slurry baffle plate, which is located at the bottom of the slurry inlet box and is inclined to the horizontal plane.

10. A mesh press wet slurry filter, characterized in that, The mesh press wet slurry filter includes a slurry pressing device and a slurry distribution device as described in any one of claims 1-9.

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