A slurry purification system and method
Patent Information
- Application Number
- CN202611389830.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-08
- Publication Date
- 2026-10-23
AI Technical Summary
一方面，多级轻质除渣单元配套的上浆泵、管路持续运行，会造成不必要的设备能耗，增加生产运行成本；另一方面，多段轻质除渣单元长期空载或者低负荷运行，设备磨损、管路堵塞的风险没有降低，设备运维工作量大
（1）本发明设置换向组件对首段轻质除渣单元的尾渣流向进行切换控制，当处理废纸回用浆等高轻渣含量的浆料时，首段轻质除渣单元的尾渣送入后段轻质除渣单元，启用所有的多级轻质除渣单元，充分脱除塑料、胶黏物等轻渣杂质，保障浆料洁净度；当处理原生木浆、高洁净商品浆这类轻渣含量低的浆料时，可将首段轻质除渣单元尾渣切回至首段重质除渣单元的进浆侧，不再向后段轻质除渣单元送料，能够关停后续多级轻质除渣单元及其配套的上浆泵，避免轻质除渣单元低负荷空转，便于降低系统的能耗，节约生产成本。
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Figure CN122960041A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of papermaking equipment, in particular to a pulp purification system and method. Background Art
[0002] In the pulp board production process of papermaking, pulp purification is one of the important processes. As the main purification equipment, cleaners are divided into heavy impurity cleaners and light impurity cleaners. The heavy impurity cleaners mainly remove heavy impurities such as sand, metal particles and hard pulp lumps, while the light impurity cleaners mainly remove low-density light slag impurities such as plastics, adhesives and foam.
[0003] Existing pulp purification systems usually combine multiple stages of heavy impurity cleaning units and multiple stages of light impurity cleaning units. The heavy impurity cleaning units adopt a multi-stage treatment mode of progressive tailings and accepted pulp reflux. All the accepted pulp output from the heavy impurity cleaning units is sent to the light impurity cleaning units, the tailings from the first stage of the light impurity cleaning units are passed into the subsequent stages of the light impurity cleaning units for further light slag separation treatment, and the entire light impurity cleaning line is put into operation. However, the existing purification system has the following disadvantages: In actual production, the working conditions of incoming materials on the production line fluctuate greatly, and both waste paper recycled pulp with high light slag content, as well as virgin wood pulp and high-cleanliness commercial pulp are processed. When processing pulps such as virgin wood pulp and high-cleanliness commercial pulp, heavy impurities inside the pulp are dominant, and the light slag content is extremely low. At this time, the existing system still needs to drive all the multi-stage light impurity cleaning units to work continuously, and the tailings of the first-stage light impurity cleaning unit are still sent to the subsequent-stage light impurity cleaning units for cyclic treatment. On the one hand, the stock pumps and pipelines supporting the multi-stage light impurity cleaning units continue to operate, which causes unnecessary equipment energy consumption and increases production operation costs; on the other hand, the multi-stage light impurity cleaning units operate under no-load or low load for a long time, the risks of equipment wear and pipeline blockage are not reduced, and the equipment operation and maintenance workload is large. Summary of the Invention
[0004] The present invention provides a pulp purification system, a production system and a method, which can solve at least one of the above technical problems.
[0005] To solve the above technical problems, in one aspect, the present invention provides a pulp purification system, comprising multiple stages of heavy impurity cleaning units arranged in sequence and multiple stages of light impurity cleaning units arranged in sequence, wherein stock pumps are respectively arranged in the multiple stages of heavy impurity cleaning units and the multiple stages of light impurity cleaning units; the multiple stages of light impurity cleaning units at least comprise a first-stage light impurity cleaning unit and a second-stage light impurity cleaning unit, and the multiple stages of heavy impurity cleaning units at least comprise a first-stage heavy impurity cleaning unit; The tailings side of the previous-stage heavy impurity cleaning unit is communicated with the pulp inlet side of the next-stage heavy impurity cleaning unit, and the accepted pulp side of the next-stage heavy impurity cleaning unit is communicated with the pulp inlet side of the previous-stage heavy impurity cleaning unit; except for the first-stage light impurity cleaning unit, the tailings side of the previous-stage light impurity cleaning unit is communicated with the pulp inlet side of the next-stage light impurity cleaning unit; The good pulp side of the first heavy slag removal unit is connected to the pulp inlet side of the first light slag removal unit. The tail slag side of the first light slag removal unit is equipped with a reversing component, which allows the tail slag side of the first light slag removal unit to be switched to be connected to the pulp inlet side of the second light slag removal unit, or to the pulp inlet side of the first heavy slag removal unit.
[0006] Secondly, the present invention provides a slurry purification method, comprising the following steps: Obtain the light slag content α1 of the slurry entering the first stage heavy slag remover, and compare α1 with the preset light slag content α. r The numerical value; If α1 is greater than α r The reversing component operates to connect the tail slag side of the first lightweight slag removal unit with the slurry inlet side of the second lightweight slag removal unit.
[0007] If α1 is less than α r The reversing component operates to connect the tailings side of the first lightweight slag removal unit with the slurry inlet side of the first heavy slag removal unit.
[0008] The beneficial effects of one or more of the above technical solutions are as follows: (1) The present invention sets a reversing component to switch the flow direction of the tail slag of the first stage light slag removal unit. When processing pulp with high light slag content such as recycled waste paper pulp, the tail slag of the first stage light slag removal unit is sent to the subsequent stage light slag removal unit, and all multi-stage light slag removal units are activated to fully remove light slag impurities such as plastics and adhesives, and ensure the cleanliness of the pulp. When processing pulp with low light slag content such as virgin wood pulp and high-cleanliness commercial pulp, the tail slag of the first stage light slag removal unit can be switched back to the pulp inlet side of the first stage heavy slag removal unit, and no more material is fed to the subsequent stage light slag removal unit. This can shut down the subsequent multi-stage light slag removal units and their matching pulp pumps, avoid the light slag removal units running at low load, reduce the energy consumption of the system, and save production costs.
[0009] (2) Under conditions of low light slag content, the downstream light slag removal unit can be shut down, reducing wear and blockage caused by long-term low load on the equipment, lowering the probability of equipment failure, and facilitating the reduction of daily inspection and maintenance workload. At the same time, the tailings are returned to the heavy slag removal unit for reprocessing, which facilitates the recovery of effective fibers in the tailings, reduces fiber loss, and improves the utilization rate of raw materials.
[0010] (3) This solution can be adapted to a variety of raw pulps with different light residue content. One system can meet the production needs of waste paper recycled pulp, virgin wood pulp and high-cleanliness commercial pulp without the need to configure two independent purification equipment for different raw materials. Attached Figure Description
[0011] Figure 1This is a schematic diagram of the process connection of the slurry purification system in an embodiment of the present invention.
[0012] 1. Slurry storage tank; 2. First slurry pump; 3. Protective screen; 4. Second slurry pump; 5. Water pump; 6. Third slurry pump; 7. Fourth slurry pump; 8. Fifth slurry pump; 9. Sixth slurry pump; 10. Seventh slurry pump; 11. Eighth slurry pump; 12. Seventh stage heavy slag removal unit; 13. Sixth stage heavy slag removal unit; 14. Fifth stage heavy slag removal unit; 15. Fourth stage heavy slag removal unit; 16. Third stage heavy slag removal unit; 17. Second stage heavy slag removal unit; 18. First stage heavy slag removal unit; 19. 20. Second main pipe; 21. Second shut-off valve; 22. Second branch pipe; 23. First branch pipe; 24. First section lightweight slag removal unit; 25. Ninth slurry pump; 26. First shut-off valve; 27. Second section lightweight slag removal unit; 28. Tenth slurry pump; 29. Third section lightweight slag removal unit; 30. Eleventh slurry pump; 31. Fourth section lightweight slag removal unit; 32. Twelfth slurry pump; 33. Thirteenth slurry pump; 34. Fifth section lightweight slag removal unit; 35. Sixth section lightweight slag removal unit; 36. Extrusion roller; 37. First main pipe. Detailed Implementation
[0013] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be noted that the following embodiments are only for explaining the invention and are not intended to limit the scope of protection of the invention. Conventional modifications made by those skilled in the art based on existing technology still fall within the scope of protection of this invention.
[0014] See Figure 1 As shown, this embodiment provides a slurry purification system, including multiple heavy slag removal units and multiple light slag removal units arranged in sequence. Each heavy slag removal unit and each light slag removal unit is equipped with a slurry pump on its slurry inlet side. The tail slag side of the preceding heavy slag removal unit is connected to the slurry inlet side of the following heavy slag removal unit, and the good slurry side of the following heavy slag removal unit is connected to the slurry inlet side of the preceding heavy slag removal unit. The multi-stage lightweight slag removal unit includes at least a first-stage lightweight slag removal unit 23 and a second-stage lightweight slag removal unit 26, and the multi-stage heavy slag removal unit includes at least a first-stage heavy slag removal unit 18; except for the first-stage lightweight slag removal unit, the tail slag side of the first-stage lightweight slag removal unit is connected to the pulp inlet side of the second-stage lightweight slag removal unit; the good pulp side of the first-stage heavy slag removal unit 18 is connected to the pulp inlet side of the first-stage lightweight slag removal unit 23.
[0015] The tail slag side of the first section of the lightweight slag removal unit 23 is provided with a reversing component, which allows the tail slag side of the first section of the lightweight slag removal unit 23 to be switched to be connected to the slurry inlet side of the second section of the lightweight slag removal unit 26, or to be connected to the slurry inlet side of the first section of the heavy slag removal unit 18.
[0016] Finally, the good pulp outlet of the first section of the lightweight slag removal unit 23 is directed toward the subsequent process, and dewatering is performed at the position of the extrusion roller 35.
[0017] In this embodiment, the slurry purification system is configured with a seven-stage heavy slag removal unit 12 and a six-stage light slag removal unit 34. The first stage heavy slag removal unit 18 includes four sets of heavy slag removers connected in parallel, and the first stage light slag removal unit 23 includes four sets of light slag removers connected in parallel. The heavy slag removal unit adopts a process of progressively advancing tailings and progressively recirculating good slurry: the tailings discharged from the previous stage heavy slag removal unit are sent to the next stage heavy slag removal unit for further processing, and the good slurry produced by the subsequent stage heavy slag removal unit is returned to the slurry inlet side of the previous stage heavy slag removal unit, realizing the progressive concentration and separation of heavy impurities. High-density impurities such as sand, metal fragments, and hard lumps are continuously removed, protecting subsequent equipment such as pumps and screens from wear by hard particles.
[0018] Specifically, the seven-stage heavy slag removal unit 12 consists of the following units arranged sequentially: the first stage heavy slag removal unit 18, the second stage heavy slag removal unit 17, the third stage heavy slag removal unit 16, the fourth stage heavy slag removal unit 15, the fifth stage heavy slag removal unit 14, the sixth stage heavy slag removal unit 13, and the seventh stage heavy slag removal unit 12. The six-stage light slag removal unit 34 consists of the following units arranged sequentially: the first stage light slag removal unit 23, the second stage light slag removal unit 26, the third stage light slag removal unit 28, the fourth stage light slag removal unit 30, the fifth stage light slag removal unit 33, and the sixth stage light slag removal unit 34.
[0019] A second slurry pump 4 is installed on the slurry inlet side of the first heavy slag removal unit 18, a third slurry pump 6 is installed on the slurry inlet side of the second heavy slag removal unit 17, a fourth slurry pump 7 is installed on the slurry inlet side of the third heavy slag removal unit 16, a fifth slurry pump 8 is installed on the slurry inlet side of the fourth heavy slag removal unit 15, a sixth slurry pump 9 is installed on the slurry inlet side of the fifth heavy slag removal unit 14, a seventh slurry pump 10 is installed on the slurry inlet side of the sixth heavy slag removal unit 13, and an eighth slurry pump 11 is installed on the slurry inlet side of the seventh heavy slag removal unit 12. The second-stage lightweight slag removal unit 26 is equipped with a ninth slurry pump 24 on the slurry inlet side, the third-stage lightweight slag removal unit 28 is equipped with a tenth slurry pump 27 on the slurry inlet side, the fourth-stage lightweight slag removal unit 30 is equipped with an eleventh slurry pump 29 on the slurry inlet side, the fifth-stage lightweight slag removal unit 33 is equipped with a twelfth slurry pump 31 on the slurry inlet side, and the sixth-stage lightweight slag removal unit 34 is equipped with a thirteenth slurry pump 32 on the slurry inlet side.
[0020] In addition, water pipes are connected to the slurry inlet side and the tailings side of the first heavy slag removal unit 18. A water pump 5 is installed on the water pipes to complete the water connection work of the entire heavy slag removal unit during the initial start-up stage.
[0021] In other embodiments, the number of segments in the slag removal unit can be adjusted. For example, the heavy slag removal unit uses 5 segments, and the light slag removal unit uses 4 segments; the first heavy slag removal unit 18 and the first light slag removal unit 23 are still multiple slag removers connected in parallel; the reversing component is still arranged on the tail slag side of the first light slag removal unit 23 to realize the two-way switching of the tail slag flow direction.
[0022] The reversing assembly includes a first branch pipe 22 and a second branch pipe 21, both of which are equipped with shut-off valves. One end of each branch pipe 22 and branch pipe 21 is connected to the tail slag side of the first-stage lightweight slag removal unit 23, and the other end of the first branch pipe 22 is connected to the slurry inlet side of the subsequent lightweight slag removal unit. The other end of the second branch pipe 21 is connected to the slurry inlet side of the first-stage heavyweight slag removal unit 18. Specifically, the shut-off valve on the first branch pipe 22 is the first shut-off valve 25, and the shut-off valve on the second branch pipe 21 is the second shut-off valve 20.
[0023] In this embodiment, a gate valve (knife gate valve) is used as the shut-off valve. In other alternative embodiments, a ball valve or a stop valve can also be used as the shut-off valve. When laying out the pipeline on site, the pipeline interface should be as close as possible to the valve body of the shut-off valve, and the distance between the pipeline interface and the valve body should not exceed 10cm, so as to shorten the high-pressure slurry pipe section and reduce pipeline resistance.
[0024] More specifically, the shut-off valves of the reversing assembly are electric gate valves, and the system is equipped with a controller whose signals are connected to each electric shut-off valve. The controller can be a PLC, a microcontroller, etc. The system can be equipped with an online slurry light slag detection device. The sampling points of the online detection device are arranged on the slurry inlet pipe of the first heavy slag removal unit 18, and the output signal of the online detection device is connected to the controller. Based on the detected light slag content, the controller automatically controls the opening and closing of the shut-off valves on the first branch pipe 22 and the second branch pipe 21 of the reversing assembly, completing the automatic switching between the two operating conditions.
[0025] It is understandable that online testing equipment may not be configured. Operators can obtain the light residue content of the pulp through offline laboratory testing, or, depending on the type of incoming pulp (virgin wood pulp / waste paper pulp), manually input switching commands into the controller, and the controller drives the electric shut-off valve to complete the reversal.
[0026] Furthermore, the first-stage lightweight slag removal unit 23 includes four first-stage lightweight slag removers arranged in parallel. Each first-stage lightweight slag remover has a first branch pipe 22 and a second branch pipe 21 independently installed on its tail slag side. Multiple first branch pipes 22 converge and connect to a first main pipe 36, which is connected to the slurry inlet side of the next-stage lightweight slag removal unit. Multiple second branch pipes 21 converge and connect to a second main pipe 19, which is connected to the slurry inlet side of the first-stage heavy slag removal unit 18. Each of the four parallel first-stage light-weight cleaners has two branch pipes led out from its tailings, which are then collected through a main pipe, ensuring that the tailings flow direction of each first-stage light-weight cleaner can be switched synchronously, and avoiding biased flow in the pipeline of a single cleaner.
[0027] The multi-stage light-weight cleaning unit further includes a second-stage light-weight cleaning unit 26, a third-stage light-weight cleaning unit 28 and a post-positioned light-weight cleaning unit; the good pulp side of the second-stage light-weight cleaning unit 26 is communicated with the heavy-duty dilution water circuit, and the good pulp side of the third-stage light-weight cleaning unit 28 is communicated with the pulp inlet side of the second-stage light-weight cleaning unit 26; the good pulp side of the post-positioned light-weight cleaning unit is communicated to the pulp inlet side of the third-stage light-weight cleaning unit 28.
[0028] In this embodiment, the post-positioned light-weight cleaning unit is divided into a fourth-stage light-weight cleaning unit 30, a fifth-stage light-weight cleaning unit 33 and a sixth-stage light-weight cleaning unit 34; the tailings sides of the fourth-stage light-weight cleaning unit 30, the fifth-stage light-weight cleaning unit 33 and the sixth-stage light-weight cleaning unit 34 are jointly connected to a main pipe, which is communicated to the pulp inlet side of the third-stage light-weight cleaning unit 28. Each stage of the light-weight cleaning unit is equipped with an independent stock pump. When the entire light-weight cleaning line is put into operation, all the stock pumps supporting the second to sixth-stage light-weight cleaning units 34 are turned on to complete the step-by-step separation of impurities such as plastic fragments, foams and light flocs.
[0029] The system further includes a pulp storage tank 1 and a protective screen 3. The pulp storage tank 1 is communicated with the pulp inlet side of the protective screen 3, and the pulp outlet side of the protective screen 3 is connected to the pulp inlet side of the first-stage heavy-weight cleaning unit 18 through a pipeline; a stock pump is arranged in series on the pipeline between the pulp storage tank 1 and the protective screen 3. The system is also equipped with a white water tank, which is communicated with the pulp storage tank 1, and a dilution water pump is arranged on the pipeline between the two, for supplementing dilution white water to the pulp storage tank 1 to adjust the pulp inlet consistency.
[0030] In the conventional purification mode with high light-weight tailing pulp content: the shut-off valve of the first branch pipe 22 in the reversing assembly is opened, and the shut-off valve of the second branch pipe 21 is closed; the tailings of the first-stage light-weight cleaning unit 23 are sent to the pulp inlet side of the second-stage light-weight cleaning unit 26 via the first branch pipe 22 and the first main pipe 36. All the stock pumps supporting the second to sixth-stage light-weight cleaning units 34 are started, and the entire multi-stage light-weight cleaning system is turned on. After the pulp passes through the first-stage heavy-weight cleaning unit 18 to remove heavy impurities, the good pulp enters the first-stage light-weight cleaning unit 23, and the tailings discharged from the first-stage light-weight cleaning unit 23 are sequentially sent to the second-stage light-weight cleaning unit 26, the third-stage light-weight cleaning unit 28, the fourth-stage light-weight cleaning unit 30, the fifth-stage light-weight cleaning unit 33, and the sixth-stage light-weight cleaning unit 34 for step-by-step treatment, so as to remove light impurities such as plastics, adhesives and foams in the pulp and ensure the cleanliness of the pulp.
[0031] In the bypass purification mode with a low light slag slurry content: the shut-off valve of the first branch pipe 22 in the reversing assembly is closed, and the shut-off valve of the second branch pipe 21 is opened; the tailings from the first-stage light slag removal unit 23 flow back to the pulp inlet side of the first-stage heavy slag removal unit 18 via the second branch pipe 21 and the second main pipe 19. At this time, tailings are no longer conveyed to the second and subsequent light slag removal units, and all the stock pumps corresponding to the second-stage light slag removal unit 26 to the sixth-stage light slag removal unit 34 are shut down on site.
[0032] The slurry only passes through the entire set of heavy slag removal units to complete the removal of heavy impurities; the tailings produced by the first-stage light slag removal unit 23 are sent back to the inlet of the first-stage heavy slag removal unit 18 for reprocessing, so as to recover the effective fibers in the tailings; the second-stage light slag removal unit 26 to the sixth-stage light slag removal unit 34 are in a bypass state and no longer participate in the purification process.
[0033] In the bypass purification mode, on the one hand, multiple stock pumps supporting the light slag removal are shut down, which directly reduces the power consumption of the motor; on the other hand, the slurry no longer flows through the second to sixth stage light slag removal chambers and pipelines, the resistance of the system pipeline decreases, and the load of the delivery pump is further reduced. At the same time, the rear-stage light slag removal units do not need to perform slag discharge, flushing and spare part replacement, which can reduce the operation and maintenance workload. The entire system can guarantee the purification quality of the slurry only by relying on the heavy slag removal units and the first-stage light slag removal unit 23.
[0034] The on-site start-up operation process of this embodiment is as follows: check and close all the drain valves of the purification system, add water to the white water tank and raise the temperature, and open the exhaust valve to exhaust when the water level reaches 95%; start the purification sealing water pump, confirm that the sealing water state at each point is normal, and complete the water series operation in the established order; when the liquid level of the pulp storage tank 1 reaches more than 30%, start the agitator in the pulp storage tank 1; after 20 minutes of water series operation, start the first stock pump 2, and adjust the stock delivery flow and the dilution water volume supplied by the white water tank according to the pulp consumption; start the stock pumps on the pulp inlet side corresponding to the heavy slag removal units and light slag removal units, and the start-up of the purification system is completed; if the bypass energy-saving mode is to be put into use, confirm that the stock pumps of the rear-stage light slag removal units are in a prohibited start state, and then operate the valves of the reversing assembly to complete the flow direction switching.
[0035] This embodiment provides a slurry purification method, comprising the following steps: Obtain the light slag content α1 of the slurry entering the first-stage heavy slag remover; here, there are three ways to obtain the light slag content α1: real-time collection through an on-line detection instrument; off-line laboratory test after sampling; indirect determination according to the variety of incoming slurry; compare the obtained α1 with the preset light slag content threshold α r to judge the magnitude relationship.
[0036] If α1 is greater than α rWhen the reversing component is activated, the tail slag side of the first section of the lightweight slag removal unit 23 is connected to the slurry inlet side of the second section of the lightweight slag removal unit, and the system enters the normal purification mode. The pump sets of the second to sixth sections of the lightweight slag removal unit 34 are turned on, and all lightweight slag removal units are put into operation to remove lightweight impurities from the slurry.
[0037] If α1 is less than α, the reversing component operates, connecting the tailings side of the first-stage lightweight slag removal unit 23 with the slurry inlet side of the first-stage heavy slag removal unit 18, and the system enters the bypass energy-saving mode. At this time, the matching slurry pumps of the second to sixth-stage lightweight slag removal units 34 can be shut down, and the downstream lightweight slag removal units bypass and do not participate in slurry treatment, reducing energy consumption and equipment wear. The tailings of the first-stage lightweight slag removal unit 23 are returned to the first-stage heavy slag removal unit 18 for reprocessing to recover the fibers in the tailings.
[0038] It should be noted that the preset threshold α for light slag content is pre-calibrated and stored based on the actual pulp type produced on the production line and the quality requirements of the finished pulp board; when the pulp type changes, the operator can modify the preset threshold α.
[0039] The specific embodiments described above should not be construed as limiting the scope of protection of this invention. Any alternative modifications or variations made to the embodiments of this invention by those skilled in the art will fall within the scope of protection of this invention. Any aspects not detailed in this invention are well-known to those skilled in the art.
Claims
1. A slurry purification system, characterized in that, It includes multiple heavy slag removal units and multiple light slag removal units arranged in sequence. Each of the multiple heavy slag removal units and multiple light slag removal units is equipped with a slurry pump. The multiple heavy slag removal unit includes at least a first heavy slag removal unit (18), and the multiple light slag removal unit includes at least a first light slag removal unit (23) and a second light slag removal unit (26). The tailings side of the first heavy slag removal unit is connected to the feed side of the second heavy slag removal unit, and the good pulp side of the second heavy slag removal unit is connected to the feed side of the first heavy slag removal unit; except for the first light slag removal unit, the tailings side of the first light slag removal unit is connected to the feed side of the second light slag removal unit. The good pulp side of the first heavy slag removal unit (18) is connected to the pulp inlet side of the first light slag removal unit (23). The tail slag side of the first light slag removal unit (23) is provided with a reversing component, which enables the tail slag side of the first light slag removal unit (23) to be switched to be connected to the pulp inlet side of the second light slag removal unit (26), or to be connected to the pulp inlet side of the first heavy slag removal unit (18).
2. The slurry purification system according to claim 1, characterized in that, The reversing assembly includes a first branch pipe (22) and a second branch pipe (21), both of which are equipped with shut-off valves. One end of the first branch pipe (22) and the second branch pipe (21) are connected to the tail slag side of the first section light slag removal unit (23), the other end of the first branch pipe (22) is connected to the slurry inlet side of the second section light slag removal unit (26), and the other end of the second branch pipe (21) is connected to the slurry inlet side of the first section heavy slag removal unit (18).
3. The slurry purification system according to claim 2, characterized in that, The first-stage lightweight slag removal unit (23) includes multiple first-stage lightweight slag removers arranged in parallel. Each first-stage lightweight slag remover has a first branch pipe (22) and a second branch pipe (21) respectively on the tail slag side. Multiple first branch pipes (22) are connected to the first main pipe (36), and the first main pipe (36) is connected to the slurry inlet side of the second-stage lightweight slag removal unit (26). Multiple second branch pipes (21) are connected to the second main pipe (19), and the second main pipe (19) is connected to the slurry inlet side of the first-stage heavy slag removal unit (18).
4. The slurry purification system according to claim 2, characterized in that, The shut-off valve is a gate valve, ball valve, or stop valve.
5. The slurry purification system according to claim 1, characterized in that, The multi-stage lightweight slag removal unit also includes a three-stage lightweight slag removal unit (28) and at least one post-lightweight slag removal unit. The good pulp side of the two-stage lightweight slag removal unit (26) is connected to the heavy dilution water circuit, and the good pulp side of the three-stage lightweight slag removal unit (28) is connected to the pulp inlet side of the two-stage lightweight slag removal unit (26). The good pulp side of the post-lightweight slag removal unit is connected to the pulp inlet side of the three-stage lightweight slag removal unit (28).
6. The slurry purification system according to claim 5, characterized in that, The post-lightweight slag removal unit is divided into a four-section lightweight slag removal unit (30), a five-section lightweight slag removal unit (33), and a six-section lightweight slag removal unit (34). The tail slag side of the four-section lightweight slag removal unit (30), the five-section lightweight slag removal unit (33), and the six-section lightweight slag removal unit (34) is connected to the main pipe, and the main pipe is connected to the slurry inlet side of the three-section lightweight slag removal unit (28).
7. The slurry purification system according to claim 1, characterized in that, It also includes a slurry storage tank (1) and a protective screen (3). The slurry storage tank (1) is connected to the slurry inlet side of the protective screen (3). The slurry outlet side of the protective screen (3) is connected to the slurry inlet side of the first heavy slag removal unit (18) through a pipeline. A slurry pump is connected in series on the pipeline between the slurry storage tank (1) and the protective screen (3).
8. The slurry purification system according to claim 7, characterized in that, It also includes a white water tank, which is connected to the slurry storage tank (1), and a dilution water pump is installed on the pipeline between the white water tank and the slurry storage tank (1).
9. The slurry purification system according to claim 1, characterized in that, The slurry purification system includes seven heavy slag removal units and six light slag removal units. The first heavy slag removal unit includes four sets of heavy slag removers connected in parallel, and the first light slag removal unit includes four sets of light slag removers.
10. A method for purifying slurry, characterized in that, The slurry purification system applied to any one of claims 1-9 includes the following steps: Obtain the light slag content α1 of the slurry entering the first stage heavy slag remover, and compare α1 with the preset light slag content α. r The numerical value; If α1 is greater than α r The reversing component operates, making the tail slag side of the first section of the lightweight slag removal unit (23) connected to the slurry inlet side of the second section of the lightweight slag removal unit (26); If α1 is less than α r The reversing component operates, causing the tail slag side of the first section of the light slag removal unit (23) to connect with the slurry inlet side of the first section of the heavy slag removal unit (18).