Papermaking white water fine sticky substance purification and separation system

Abstract

The invention discloses a system for purifying and separating papermaking white water fine stickies, and belongs to the technical field of pulping and papermaking wastewater treatment. Comprising a physical grading deslagging unit, a chemical modification treatment unit, a biological enzymolysis reaction unit and a slurry forming unit which are sequentially communicated through a conveying pipeline I, wherein a conveying pipeline II is arranged between a feeding hole of the physical grading deslagging unit and a waste slurry discharging hole of the slurry forming unit, and a white water deep filtering unit is arranged on the conveying pipeline II; the physical grading deslagging unit, the chemical modification treatment unit, the biological enzymolysis reaction unit and the white water deep filtering unit can form a white water backflow circulation path through a conveying pipeline I and a conveying pipeline II. The system for purifying and separating the fine stickies in the papermaking white water, disclosed by the invention, can realize graded and accurate removal of the stickies with large, medium and small particle sizes in the papermaking white water, and effectively solves the problems of deposition and scaling of the stickies in equipment.

Description

Technical Field

[0001] This invention belongs to the field of pulp and paper wastewater treatment technology, specifically relating to a purification and separation system for fine adhesives in papermaking white water. Background Technology

[0002] Waste paper recycling is an important way for the pulp and paper industry to achieve resource recycling. However, a large amount of adhesives are generated during the repeated recycling process. These adhesives are prone to deposit and scale in papermaking equipment and white water circulation pipes, which can block the pipes, affect the normal operation of the paper machine, and also lead to a decrease in indicators such as the breaking length and bursting index of the finished paper, thus reducing the quality of the finished paper.

[0003] Currently, the paper industry mostly uses single physical, chemical or biological methods to remove adhesives, and the corresponding treatment devices can only achieve single functions, such as simple fine screening and slag removal devices or chemical adsorption reaction tanks. They cannot achieve precise removal of adhesives of different particle sizes, and there is a lack of effective connection between the various treatment links, resulting in poor white water purification and low recycling rate. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a purification and separation system for fine adhesives in papermaking white water, which can achieve precise removal of large, medium and small particle size adhesives in papermaking white water, and effectively solve the problem of adhesive deposition and scaling in the equipment.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a papermaking white water micro-adhesive purification and separation system, comprising a physical classification and slag removal unit, a chemical modification treatment unit, a biological enzymatic hydrolysis reaction unit and a pulp forming unit connected in sequence through a conveying pipeline; Wherein, a second conveying pipeline is provided between the feed inlet of the physical grading and slag removal unit and the waste slurry discharge outlet of the slurry forming unit, and a white water depth filtration unit is provided on the second conveying pipeline. The physical grading and slag removal unit, the chemical modification treatment unit, the biological enzymatic hydrolysis reaction unit, and the white water deep filtration unit can form a white water reflux circulation path through the first conveying pipeline and the second conveying pipeline.

[0006] Optionally, the physical grading and slag removal unit includes a fine screening device and a thermal dispersion device. The inlet of the fine screening device is connected to the first conveying pipeline, and the outlet of the fine screening device and the inlet of the thermal dispersion device are connected through the first conveying pipeline.

[0007] Optionally, the chemical modification treatment unit includes a mixing reaction vessel with several auxiliary agent addition ports.

[0008] Optionally, the biological enzymatic hydrolysis reaction unit includes an enzymatic hydrolysis vessel, which is equipped with a temperature control module and a pH detection module.

[0009] Optionally, the slurry forming unit includes a forming machine and a press, and the feed inlet of the forming machine is connected to the discharge outlet of the enzymatic hydrolysis tank through the conveying pipeline.

[0010] Optionally, the white water deep filtration unit includes a multi-disc filter and a white water pretreatment tank with a filter aid addition port on the top, wherein the outlet of the white water pretreatment tank is connected to the inlet of the multi-disc filter.

[0011] Optionally, a flow regulating valve is provided on the first conveying pipeline between the physical grading and slag removal unit, the chemical modification treatment unit, the biological enzymatic hydrolysis reaction unit and the slurry forming unit, and a flow regulating valve is provided on the second conveying pipeline between the slurry forming unit and the white water deep filtration unit.

[0012] Optionally, slurry pumps are installed on the first conveying pipeline and the second conveying pipeline.

[0013] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: By setting up four core functional units—a physical grading and slag removal unit, a chemical modification treatment unit, a biological enzymatic reaction unit, and a deep white water filtration unit—and connecting these units sequentially, precise grading removal of adhesive substances can be achieved. Specifically, the physical grading and slag removal unit first removes large-particle adhesive substances, then the chemical modification treatment unit adsorbs and passivates fine adhesive substances, followed by the biological enzymatic reaction unit decomposes the sticky components of the adhesive substances, and finally the deep white water filtration unit deeply purifies the white water. This solves the problem of poor removal efficiency with a single device and effectively reduces the deposition and scaling of adhesive substances in the equipment. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a schematic diagram of the process for purifying and separating fine adhesives in papermaking white water according to a preferred embodiment of the present invention; The system includes: 1. Physical grading and slag removal unit; 11. Fine screening device; 12. Thermal dispersion device; 2. Chemical modification treatment unit; 21. Mixing reaction tank; 3. Biological enzymatic hydrolysis reaction unit; 31. Enzymatic hydrolysis tank; 4. Slurry forming unit; 41. Forming machine; 42. Press; 5. White water deep filtration unit; 51. Multi-disc filter; 52. White water pretreatment tank; 6. Conveying pipeline one; 61. Flow regulating valve; 7. Conveying pipeline two; 71. Flow regulating valve two; 8. Slurry pump. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention and therefore only show the components relevant to the present invention.

[0017] It should be noted that if directional indicators (such as up, down, bottom, top, etc.) are involved in this embodiment, these directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly. The terms "first" and "second" are used 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, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature. Unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0018] like Figure 1 As shown, a papermaking white water micro-adhesive purification and separation system includes a physical grading and slag removal unit 1, a chemical modification treatment unit 2, a biological enzymatic reaction unit 3, and a pulp forming unit 4, which are connected sequentially through a conveying pipeline 1 6. A conveying pipeline 2 7 is provided between the inlet of the physical grading and slag removal unit 1 and the waste pulp discharge outlet of the pulp forming unit 4. A white water deep filtration unit 5 is provided on the conveying pipeline 2 7. The physical grading and slag removal unit 1, the chemical modification treatment unit 2, the biological enzymatic reaction unit 3, and the white water deep filtration unit 5 can form a white water reflux circulation path through the conveying pipeline 1 6 and the conveying pipeline 2 7.

[0019] By setting up four core functional units—physical grading and slag removal unit 1, chemical modification treatment unit 2, biological enzymatic hydrolysis reaction unit 3, and white water deep filtration unit 5—and connecting these units sequentially, precise grading and removal of adhesive substances can be achieved. Specifically, the physical grading and slag removal unit 1 first removes large-particle adhesive substances; then, the chemical modification treatment unit 2 adsorbs and passivates fine adhesive substances; next, the biological enzymatic hydrolysis reaction unit 3 decomposes the sticky components of the adhesive substances; and finally, the white water deep filtration unit 5 deeply purifies the white water. This solves the problem of poor removal efficiency with a single device and effectively reduces the deposition and scaling of adhesive substances in the equipment.

[0020] Specifically, such as Figure 1As shown, the physical grading and slag removal unit 1 includes a fine screening device 11 and a thermal dispersion device 12. The feed inlet of the fine screening device 11 is connected to the conveying pipeline 6, and the discharge outlet of the fine screening device 11 and the feed inlet of the thermal dispersion device 12 are connected through the conveying pipeline 6. The thermal dispersion device 12 is an existing technology in the conventional technology of pulp and paper making, and the fine screening device 11 is an adjustable screen gap vibrating fine screen in the conventional technology of this field. The fine screening device 11 is equipped with a light slag removal port, and the screen gap adjustment range is 0.15 to 0.25 mm.

[0021] The above, such as Figure 1 As shown, the chemical modification treatment unit 2 includes a mixing reaction tank 21. The mixing reaction tank 21 is equipped with several additive addition ports. Bentonite, cationic polyacrylamide, and ternary additives can be added to the tank through these ports. The additives are then thoroughly mixed and reacted with the slurry through the stirring paddle structure inside the mixing reaction tank 21. Simultaneously, each additive addition port is equipped with a metering feeder to ensure precise addition of the additives. The mixing reaction tank 21 contains a stirring paddle, and the stirring speed can be adjusted according to the slurry viscosity to ensure thorough mixing of the additives and the slurry.

[0022] The above, such as Figure 1 As shown, the bio-enzymatic hydrolysis reaction unit 3 includes an enzymatic hydrolysis tank 31, which is equipped with a temperature control module and a pH detection module. The temperature control module regulates the ambient temperature within the enzymatic hydrolysis tank 31 to promote the enzymatic hydrolysis reaction. The pH detection module monitors and provides real-time feedback on the pH value of the slurry within the enzymatic hydrolysis tank 31, facilitating monitoring of the enzymatic hydrolysis process.

[0023] The above, such as Figure 1 As shown, the pulp forming unit 4 is composed of a forming machine 41 and a press 42, which are conventional technologies in the pulp and paper making field. The feed inlet of the forming machine 41 is connected to the discharge outlet of the enzymatic hydrolysis tank 31 through a conveying pipeline 6.

[0024] The above, such as Figure 1 As shown, the white water deep filtration unit 5 includes a multi-disc filter 51 and a white water pretreatment tank 52 with a filter aid addition port on the top. The outlet of the white water pretreatment tank 52 is connected to the inlet of the multi-disc filter 51. The white water pretreatment tank 52 has a built-in stirring blade structure, which can be used to mix the filter aid with the white water to be treated. At the same time, the multi-disc filter 51 is provided with white water classification outlets, namely ultra-clear white water outlet, clear white water outlet and turbid white water outlet. Each outlet is connected to the white water return circulation path. The purified white water is returned to the physical classification and slag removal unit 1 through the white water return circulation path, which can realize the closed-loop recycling of white water and greatly improve the water resource utilization rate. At the same time, the fine fibers collected by the multi-disc filter 51 can be reused to improve the resource utilization rate.

[0025] In this embodiment, such as Figure 1 As shown, a flow regulating valve 61 is installed on the conveying pipeline 6 between the physical grading and slag removal unit 1, the chemical modification treatment unit 2, the biological enzymatic reaction unit 3 and the slurry forming unit 4, and a flow regulating valve 71 is installed on the conveying pipeline 7 between the slurry forming unit 4 and the white water depth filtration unit 5, so as to accurately regulate the flow rate of slurry conveying between each unit.

[0026] Meanwhile, in this embodiment, a slurry pump 8 is installed on the first conveying pipeline 6 and the second conveying pipeline 7, which can provide pumping power for conveying slurry in the first conveying pipeline 6 and the second conveying pipeline 7.

[0027] Working principle: During operation, waste paper pulp can pass through the fine screening device 11 to remove large-particle adhesives, reducing the load on the thermal dispersion device 12; the thermal dispersion device 12 then softens and breaks down the remaining adhesives, and the pulp then passes through the chemical modification treatment unit 2 to adsorb and passivate the fine adhesives, and then the bio-enzymatic reaction unit 3 decomposes the lipid components of the adhesives; the pulp is formed into paper, and the white water generated is pretreated and then filtered in stages by the multi-disc filter 51, the purified white water is recycled and reused, and the collected fine fibers are also reused in pulping, realizing the graded removal of adhesives and the closed-loop circulation of white water.

[0028] Based on the preferred embodiments of the present invention described above, 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 purification and separation system for fine adhesives in papermaking white water, characterized in that: It includes a physical grading and slag removal unit (1), a chemical modification treatment unit (2), a biological enzymatic hydrolysis reaction unit (3) and a slurry forming unit (4) connected in sequence through a conveying pipeline (6). Among them, a second conveying pipeline (7) is provided between the feed inlet of the physical grading and slag removal unit (1) and the waste slurry discharge outlet of the slurry forming unit (4), and a white water depth filtration unit (5) is provided on the second conveying pipeline (7). The physical grading and slag removal unit (1), the chemical modification treatment unit (2), the biological enzymatic hydrolysis reaction unit (3), and the white water deep filtration unit (5) can form a white water return circulation path through the first conveying pipeline (6) and the second conveying pipeline (7).

2. The papermaking white water micro-adhesive purification and separation system according to claim 1, characterized in that: The physical grading and slag removal unit (1) includes a fine screening device (11) and a thermal dispersion device (12). The feed inlet of the fine screening device (11) is connected to the first conveying pipeline (6), and the discharge outlet of the fine screening device (11) and the feed inlet of the thermal dispersion device (12) are connected through the first conveying pipeline (6).

3. The papermaking white water micro-adhesive purification and separation system according to claim 1, characterized in that: The chemical modification treatment unit (2) includes a mixing reaction vessel (21), which is provided with several auxiliary agent addition ports.

4. The papermaking white water micro-adhesive purification and separation system according to claim 1, characterized in that: The biological enzymatic hydrolysis reaction unit (3) includes an enzymatic hydrolysis tank (31), which is equipped with a temperature control module and a pH detection module.

5. The papermaking white water micro-adhesive purification and separation system according to claim 4, characterized in that: The slurry forming unit (4) includes a forming machine (41) and a press (42). The feed inlet of the forming machine (41) is connected to the discharge outlet of the enzymatic hydrolysis tank (31) through the conveying pipeline (6).

6. The papermaking white water micro-adhesive purification and separation system according to claim 1, characterized in that: The white water deep filtration unit (5) includes a multi-disc filter (51) and a white water pretreatment tank (52) with a filter aid addition port on the top. The outlet of the white water pretreatment tank (52) is connected to the inlet of the multi-disc filter (51).

7. The papermaking white water micro-adhesive purification and separation system according to claim 1, characterized in that: A flow regulating valve (61) is provided on the first conveying pipeline (6) between the physical grading and slag removal unit (1), the chemical modification treatment unit (2), the biological enzymatic hydrolysis reaction unit (3) and the slurry forming unit (4), and a flow regulating valve (71) is provided on the second conveying pipeline (7) between the slurry forming unit (4) and the white water deep filtration unit (5).

8. The papermaking white water micro-adhesive purification and separation system according to claim 1, characterized in that: Slurry pumps (8) are installed on the first (6) and the second (7) of the conveying pipeline.

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