Advanced treatment system for high-gram-weight raw paper white water

Abstract

A high-gram-weight raw paper white water advanced treatment system relates to the technical field of white water treatment and comprises a disc filter, and the outlet end of the disc filter is respectively connected with an ultra-clear filtrate tank and a clear filtrate tank; the outlet end of the ultra-clear filtrate tank is connected with a tubular filter, and the outlet end of the tubular filter is connected with a net pressure part high-pressure sprayer; and the outlet end of the clear filtrate tank is connected with the ultra-clear filtrate tank through a circulating fine filtration structure. The utility model solves the problem that in the prior art, the treatment depth of clear filtrate and ultra-clear filtrate after white water is treated by a physicochemical treatment method or a biological treatment method does not reach the degree that the clear filtrate and the ultra-clear filtrate can be used for high-pressure spray water of a net part.

Description

Technical Field

[0001] This utility model relates to the field of white water treatment technology, specifically to a deep white water treatment system for high basis weight base paper. Background Technology

[0002] With increasingly stringent emission standards in the paper industry and companies placing greater emphasis on energy conservation, cost reduction, and efficiency improvement, conserving clean water, lowering water costs, and minimizing wastewater discharge have become increasingly important. White water recycling provides an excellent solution for water conservation in papermaking and has achieved substantial results. However, clean water is still required in many parts of the paper machine during operation, such as the spray water in the wire pressing section.

[0003] The spray water in the wire pressing section of a paper machine can be broadly divided into low-pressure spray water and high-pressure spray water. Low-pressure spray water is mainly used to rinse the guide roll surface, lubricate the vacuum zone inside the vacuum roller, lubricate the guide roll doctor blade, and lubricate the vacuum box, preventing problems such as pulp sticking to the guide roll surface, excessive wear of the guide roll, and excessive wear of the forming wire. High-pressure spray water is mainly used to rinse the forming wire, felt, and vacuum roller in the wire pressing section, preventing problems such as clogging of the forming wire gaps, felt gaps, and vacuum roller orifices. High- and low-pressure spray water in the wire pressing section typically uses needle-type, fan-shaped, or conical nozzles with small orifice diameters, which are prone to clogging; therefore, clean water is usually used. These parts are dispersed, and the water consumption in each individual part is small, making the centralized treatment and recycling of sprayed water somewhat difficult.

[0004] Therefore, many companies began to try using purified papermaking white water to replace clean water for spraying in the wire pressing section of paper machines. This could reduce clean water consumption and save costs, while also reducing wastewater discharge from the production workshop and lowering wastewater treatment costs. However, because white water contains a large amount of fine fibers, fillers, and adhesives, it easily clogs the spray nozzles, significantly impacting production stability. This greatly affects the utilization rate of white water.

[0005] A prior art patent, CN211227851U, discloses a solution comprising a white water tower, a multi-disc thickener, an ultra-clear white water tank, an arc-shaped screen, and a filtered ultra-clear white water tank, all connected in sequence. The multi-disc thickener has three filtrate outlets: a turbid filtrate outlet connected to the turbid white water tank, a clear filtrate outlet connected to the clear white water tank, and an ultra-clear filtrate outlet connected to the ultra-clear white water tank. The ultra-clear white water tank is connected to the arc-shaped screen, which includes an impurity outlet and a filtered ultra-clear filtrate outlet. The impurity outlet is connected to the turbid white water tank, and the filtered ultra-clear filtrate outlet is connected to the filtered ultra-clear white water tank. This white water treatment system can remove fine fibers and fillers from the white water, purifying it to meet the requirements for spray water in the mesh pressure section, and effectively solving the problem of spray nozzle clogging.

[0006] Existing devices, including those mentioned above, have gradually revealed shortcomings in the technology with use, mainly in the following aspects:

[0007] During the papermaking process, a large amount of white water is generated in the wire section that needs to be recycled. Current technologies generally employ physicochemical treatment and biological treatment. Physicochemical treatment mainly includes sedimentation / flotation and coagulation sedimentation, while biological treatment mainly includes activated sludge and bioenzyme methods. However, in actual production, the treatment depth of the clear filtrate and ultra-clear filtrate has not yet reached the level that it can be used as high-pressure spray water in the wire section.

[0008] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Utility Model Content

[0009] To achieve the above objectives, this utility model provides a high-grammage base paper white water deep treatment system to solve the problem that the treatment depth of the clear filtrate and ultra-clear filtrate after the white water is treated by physical-chemical or biological treatment methods in traditional technologies has not reached the level that can be used as high-pressure spray water in the wire section.

[0010] A high-grammage base paper white water deep treatment system includes a disc filter, the outlet end of which is connected to an ultra-clear filtrate tank and a clear filtrate tank.

[0011] The outlet end of the ultra-clear filtrate tank is connected to a tubular filter, and the outlet end of the tubular filter is connected to a high-pressure spray from the mesh pressure section.

[0012] The outlet end of the filtrate tank is connected to the ultra-clean filtrate tank through a circulating fine filtration structure.

[0013] As an optimized solution, the circulating fine filtration structure includes a rotating fiber screen connected to the outlet end of the filtrate tank, the outlet end of the rotating fiber screen is connected to a bag filter, and the outlet end of the bag filter is connected to the ultra-clean filtrate tank.

[0014] As an optimized solution, a rotating filtrate tank is connected between the rotating fiber screen and the bag filter.

[0015] As an optimized solution, a fully automatic cleaning filter is connected between the rotary filtrate tank and the bag filter.

[0016] As an optimized solution, a fine filtration pump is connected between the fully automatic cleaning filter and the rotary filtrate tank.

[0017] As an optimized solution, an ultra-clear filtrate pump is connected between the filtrate tank and the rotating fiber screen.

[0018] As an optimized solution, the ultra-clear filtrate pump is also connected to the ultra-clear filtrate tank.

[0019] As an optimized solution, the inlet end of the tubular filter is connected in parallel to two white water inlet pipelines.

[0020] As an optimized solution, each of the white water inlet pipelines is connected to a high-pressure water pump from the network pressure section.

[0021] Compared with the prior art, the beneficial effects of this utility model are:

[0022] White water is recycled for use as high-pressure spray water in the mesh section. First, the white water is filtered through a multi-disc filter, and then enters the clear filtrate tank and the ultra-clear filtrate tank. Next, the white water is combined before the pump and enters the rotary fiber screen, and then enters the self-cleaning filter and bag filter for filtration through the fine filter pump. The filtered white water returns to the ultra-clear filtrate tank, and finally enters the mesh section and pressing section for spraying after being filtered by the tubular filter.

[0023] This deep white water recycling process can improve the recycling rate of white water for use as high-pressure spray water in the wire section, reduce the water consumption per ton of paper in the papermaking system, and at the same time reduce the loss of fibers, fine fibers and fillers, reduce the consumption of chemicals, and reduce environmental pollution. The water quality can be reduced from 50 ppm to 5 ppm. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0025] Figure 1 This is a schematic diagram of the structure of this utility model.

[0026] In the diagram: 1-Disc filter, 2-Ultra-clear filtrate tank, 3-Clean filtrate tank, 4-Rotating fiber screen, 5-Rotating filtrate tank, 6-Bag dust collector, 7-Fully automatic cleaning filter, 8-Fine filter pump, 9-Tube filter, 10-High-pressure spray in mesh pressure section, 11-White water inlet pipeline, 12-High-pressure water pump in mesh pressure section; 13-Ultra-clear filtrate pump. Detailed Implementation

[0027] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0028] like Figure 1As shown, the high grammage base paper white water deep treatment system includes a disc filter 1, and the outlet end of the disc filter 1 is connected to an ultra-clear filtrate tank 2 and a clear filtrate tank 3 respectively.

[0029] The outlet end of the ultra-clear filtrate tank 2 is connected to a tubular filter 9, and the outlet end of the tubular filter 9 is connected to the high-pressure spray 10 of the mesh pressure section.

[0030] The outlet end of the clean filtrate tank 3 is connected to the ultra-clean filtrate tank 2 through a circulating fine filtration structure.

[0031] The circulating fine filtration structure includes a rotating fiber screen 4 connected to the outlet end of the filtrate tank 3, a bag filter 6 connected to the outlet end of the rotating fiber screen 4, and the outlet end of the bag filter 6 connected to the ultra-clean filtrate tank 2.

[0032] A rotating filtrate tank 5 is connected between the rotating fiber screen 4 and the bag filter 6.

[0033] A fully automatic cleaning filter 7 is connected between the rotary filtrate tank 5 and the bag filter 6.

[0034] A fine filtration pump 8 is connected between the fully automatic cleaning filter 7 and the rotary filtrate tank 5.

[0035] An ultra-clear filtrate pump 13 is connected between the filtrate tank 3 and the rotating fiber screen 4.

[0036] The ultra-clear filtrate pump 13 is also connected to the ultra-clear filtrate tank 2.

[0037] Two white water inlet pipes 11 are connected in parallel at the inlet end of the tubular filter 9.

[0038] Each white water inlet pipe 11 is connected to a high-pressure water pump 12 of the network pressure section.

[0039] The fully automatic cleaning filter 7 has a filtration accuracy of 50μm.

[0040] The filtration accuracy of bag filter 6 is 5μm.

[0041] The rotary fiber sieve 4 has a mesh size of 150 and a filtration accuracy of 100μm.

[0042] The tubular filter 9 has a filtration accuracy of 100μm.

[0043] The working steps of this system are as follows:

[0044] Step 1: A multi-disc filter receives three white water samples: a first white water sample, a second white water sample, and a third white water sample. The first white water sample is the white water recovered from the cylinder wire forming process during pulping and papermaking; its concentration is 5 wt%. The second white water sample is the turbid filtrate squeezed out during vacuum filtration in the white water recovery process of the multi-disc filter; its concentration is 0.8 wt%. The third white water sample is the clear filtrate filtered out during the white water recovery process of the multi-disc filter; its concentration is 0.6 wt%. After thorough filtration, white water with a suspended particulate matter concentration (TSS) < 100 ppm and a turbidity < 50 NTU is obtained.

[0045] The second step is to treat the white water using a vibrating screen with a mesh size of 150 and a filtration accuracy of 100μm. The white water obtained after passing through the vibrating screen has a suspended particulate matter concentration (TSS) of <30ppm and a turbidity of <10NTU.

[0046] The third step involves further filtering the white water using a fully automatic cleaning filter and a bag filter. The white water passes through a fully automatic cleaning filter with a filtration precision of 50μm and a filtration area of ​​0.41㎡ to obtain primary treated white water. The primary treated white water has a suspended particulate matter concentration (TSS) of <10ppm and a turbidity of <8NTU. The white water then passes through a bag filter with a filtration precision of 5μm to obtain secondary treated white water. The secondary treated white water has a suspended particulate matter concentration (TSS) of <2ppm and a turbidity of <5NTU.

[0047] Step 4: The finely filtered white water returns to the ultra-clear filtrate tank and is then filtered again by a tubular filter with a filtration accuracy of 100μm through a high-pressure spray pump in the mesh section. After filtration, it can be used for high-pressure spraying in the mesh section. The white water filtered by the tubular filter has a TSS <1ppm and a turbidity <3NTU.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A high-grammage base paper white water deep treatment system, characterized in that: Includes a disc filter (1), the outlet end of which is connected to an ultra-clean filtrate tank (2) and a clean filtrate tank (3); The outlet end of the ultra-clear filtrate tank (2) is connected to a tubular filter (9), and the outlet end of the tubular filter (9) is connected to a high-pressure spray (10) of the mesh pressure section. The outlet end of the filtrate tank (3) is connected to the ultra-clean filtrate tank (2) through a circulating fine filtration structure.

2. The high basis weight base paper white water deep treatment system according to claim 1, characterized in that: The circulating fine filtration structure includes a rotating fiber screen (4) connected to the outlet end of the filtrate tank (3), and a bag filter (6) is connected to the outlet end of the rotating fiber screen (4). The outlet end of the bag filter (6) is connected to the ultra-clean filtrate tank (2).

3. The high basis weight base paper white water deep treatment system according to claim 2, characterized in that: A rotating filtrate tank (5) is connected between the rotating fiber sieve (4) and the bag filter (6).

4. The high basis weight base paper white water deep treatment system according to claim 3, characterized in that: An automatic cleaning filter (7) is connected between the rotary filtrate tank (5) and the bag filter (6).

5. The high basis weight base paper white water deep treatment system according to claim 4, characterized in that: A fine filtration pump (8) is connected between the fully automatic cleaning filter (7) and the rotary filtrate tank (5).

6. The high basis weight base paper white water deep treatment system according to claim 5, characterized in that: An ultra-clear filtrate pump (13) is connected between the filtrate tank (3) and the rotating fiber screen (4).

7. The high basis weight base paper white water deep treatment system according to claim 6, characterized in that: The ultra-clear filtrate pump (13) is also connected to the ultra-clear filtrate tank (2).

8. The high basis weight base paper white water deep treatment system according to claim 1, characterized in that: The inlet end of the tubular filter (9) is connected to two white water inlet pipes (11) in parallel.

9. The high basis weight base paper white water deep treatment system according to claim 8, characterized in that: Each of the white water inlet pipelines (11) is connected to a high-pressure water pump (12) of the network pressure section.

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