A sludge plate-frame dewatering machine and use method thereof

Abstract

The present invention discloses a sludge plate-frame dewatering machine and a method of using the same, and belongs to the field of sewage treatment equipment. The plate frame of the dewatering machine is made of non-ferromagnetic material, and a magnetic block is provided on the inward side of the side cloth layer of the filter cloth. In two adjacent filter cloths, the magnetic blocks on the two adjacent side cloth layers are aligned with each other and have the same magnetic pole direction. The present invention utilizes the magnetic force of opposite attraction to deform the filter cloth part when the plate frame is pulled open, increases the mesh of the filter cloth, and tilts the side cloth layer relative to the mud cake, which is conducive to peeling off the mud cake and continuing to increase the distance between the plate frames. At the moment when the magnetic block loses the magnetic force constraint of opposite attraction, the pulled filter cloth rebounds to the plate frame wrapped by it, and can shake off the tightly adhered mud blocks. While realizing automatic mud unloading, the present invention makes it difficult for the sludge to block the mesh of the filter cloth, which is conducive to increasing the number of times the filter cloth is used before replacement and reducing the situation of manual mud shoveling.

Description

Technical Field

[0001] The invention relates to a sludge plate-frame dewatering machine and a use method thereof, belonging to the field of sewage treatment equipment. Background Art

[0002] At present, most sewage treatment lines use the AAO process to remove organic matter, nitrogen and phosphorus from sewage. The AAO process mainly includes three stages: anaerobic, anoxic and aerobic. The sewage will pass through the anaerobic tank, anoxic tank, aerobic tank and the secondary sedimentation tank connected to the biochemical tank (the general term for anaerobic, anoxic and aerobic tanks). In the aerobic tank, nitrifying bacteria convert ammonia nitrogen in the sewage into nitrates. The sewage containing nitrates in the aerobic tank is returned to the anoxic tank. In the anoxic tank, denitrifying bacteria convert the nitrates brought by the internal return into nitrogen gas and discharge it into the atmosphere, thereby achieving denitrification; in the anaerobic tank, polyphosphate bacteria release phosphorus and absorb easily degradable organic matter such as low-level fatty acids. In the aerobic tank, polyphosphate bacteria absorb excessive phosphorus and form sludge in the secondary sedimentation tank. Part of the sludge is discharged to remove phosphorus, and part of the sludge is returned to the anaerobic tank to ensure the microbial concentration of the biochemical tank.

[0003] Dewatering the discharged sludge is an important part of sludge discharge. At present, the main mechanical sludge dewatering equipment includes screw stack dewatering machine, belt dewatering machine, centrifugal dewatering machine, and plate and frame dewatering machine. According to the current national mud quality standard for sludge disposal in urban sewage treatment plants, the basic requirement is that the sludge moisture content is less than 60%. Among the above dewatering machines, only the plate and frame dewatering machine can stably achieve this. From the current domestic sludge disposal policy and reduction demand, the requirement for sludge moisture content is bound to decline. Under this trend, belt dewatering machines will also be gradually replaced by plate and frame machines.

[0004] Compared with other mechanical sludge dewatering methods, the plate and frame dewatering machine has an incomparable advantage of low moisture content, but the plate and frame dewatering machines currently on the market also have some obvious shortcomings. The longer the filter cloth of the plate and frame dewatering machine is used, the more serious the blockage of the filter cloth mesh is, resulting in a decrease in the dewatering effect and an increase in the sludge moisture content. After multiple squeezing, the sludge blocks the mesh of the filter cloth and hardens, causing the filter cloth to lose its elasticity and unable to fall off automatically. Manual shoveling of the mud is required, which is labor-intensive and labor-intensive, seriously affecting the dewatering efficiency.

[0005] Please refer to Figure 1 , the filter cloth of the plate and frame dehydrator is as follows Figure 1 As shown in a, it includes a filter cartridge 92 and two parallel side fabric layers 91. An opening 911 is provided in the middle of the side fabric layer 91. The two ends of the filter cartridge 92 are respectively connected to the opening 911 of a side fabric layer 91. The structure of the plate frame is as shown in FIG. Figure 1As shown in b, a pit 82 is provided in the middle for forming a mud cake, and a conveying through hole 81 is provided in the middle of the pit 82 for conveying fluid sludge.

[0006] The operation of installing the filter cloth on the plate frame is as follows: roll one of the side cloth layers 91 of the filter cloth into a cylinder, insert it into the conveying through hole 81 from one side of the plate frame, and then unfold it on the other side of the plate frame, so that the filter cylinder 92 is coaxially located in the conveying through hole 81 of the plate frame, and the two side cloth layers 91 are respectively located on one side of the plate frame, and then the binding bands 912 on the edges of the two side cloth layers are tied one by one, so that the filter cloth wraps the plate frame. The operation of removing the filter cloth from the plate frame is the opposite: first untie the binding bands 912 one by one, then roll one of the side cloth layers 91 into a cylinder, and take the rolled side cloth layer 91 out of the conveying through hole 81 of the plate frame.

[0007] A plate and frame dehydrator has dozens of plates and frames, and a 10,000-ton / day sewage treatment plant usually needs three plate and frame dehydrators. It should be noted that the plates and frames are arranged densely on the plate and frame dehydrator, which is not convenient for operation; it is also unsafe to climb on large machinery to replace the filter cloth, and the plates and frames usually need to be removed from the plate and frame dehydrator before replacing the filter cloth. Summary of the invention

[0008] In order to overcome the deficiencies of the prior art, the present invention provides a sludge plate-frame dewatering machine which can automatically unload sludge and allow the filter cloth to be used more times before replacement, and provides a method for using the same.

[0009] The technical solution adopted by the present invention to solve its technical problem is:

[0010] In the first aspect, the present application provides a sludge plate and frame dewatering machine, comprising a plate frame arranged parallel to each other on a first track, the plate frame being wrapped with filter cloth, a conveying through hole being provided in the middle of the plate frame, the filter cloth comprising two side cloth layers and a filter cartridge located in the conveying through hole, an opening being provided in the middle of the side cloth layer, and each end of the filter cartridge is connected to the opening of a side cloth layer, the plate frame is made of non-ferromagnetic material, a magnetic block is provided on an inward side of the side cloth layer, and in two adjacent pieces of the filter cloth, the magnetic blocks on two adjacent side cloth layers are aligned with each other and have the same magnetic pole direction.

[0011] The sludge plate and frame dewatering machine provided by the present application, after the plates and frames are densely arranged and pressed, the magnetic blocks on the two adjacent side cloth layers (derived from two filter cloths, because the two side cloth layers on the same filter cloth are separated by the plate frame and are not directly adjacent) are attracted by opposite sex, and the two adjacent side cloth layers are partially bonded, and the unbonded parts are filled with sludge. After the squeezing is completed, when the two adjacent plate frames are gradually pulled apart, the filter cloth moves with the plate frames, but the magnetic blocks are still attracted to the magnetic blocks of the adjacent side cloth layers, the filter cloth will be stretched open, and the mesh gap of the filter cloth will increase, which is conducive to the separation of the mud cake and the filter cloth; the distance between the two adjacent plate frames continues to increase, and the side cloth layer will become unable to remain parallel to the mud cake due to the pulling, and the mud cake will be gradually peeled off; the pulled side cloth layer gradually accumulates elastic force, and when the elastic force is greater than the magnetic force, the magnetic block loses the magnetic constraint of opposite sex attraction, and the side cloth layer rebounds at the moment of separation, which can shake off the stubborn sludge on the filter cloth.

[0012] Furthermore, on the same filter cloth, the magnetic blocks on the two side cloth layers overlap in position and have the same magnetic pole direction.

[0013] Furthermore, a plurality of the magnetic blocks are arranged on a single side cloth layer, and a projection area of ​​a single magnetic block on the plate frame is less than 2% of an area of ​​the plate frame; and on a single side cloth layer, a total projection area of ​​all the magnetic blocks on the plate frame is less than 8% of an area of ​​the plate frame.

[0014] Furthermore, on the single side cloth layer, the plurality of magnetic blocks are distributed in rows and columns, the connection line of the magnetic blocks in the same row is parallel to the horizontal plane, and the connection line of the magnetic blocks in the same column is perpendicular to the horizontal plane and does not pass through the opening.

[0015] Furthermore, the magnetic block is in a frustum shape, with a side with a larger bottom area connected to the side cloth layer and a side with a smaller bottom area facing the plate frame.

[0016] Furthermore, the sludge plate and frame dewatering machine also includes an auxiliary mud unloading mechanism running on a second track, the second track is parallel to the first track, the auxiliary mud unloading mechanism includes a suspension platform, the suspension platform is provided with at least one pair of vertically downward telescopic arms, the telescopic arms are provided with electromagnets, the electromagnets on the paired telescopic arms are aligned with each other and separated, and the distance between them is greater than the thickness of a piece of the plate frame.

[0017] Furthermore, a mud scraping mechanism is also provided on the telescopic arm, and the mud scraping mechanism includes a scraper, a coil spring and a mounting plate connected to the telescopic arm, and a fixed shaft and a freely rotatable rotating shaft are provided on the mounting plate, and the rotating shaft is radially connected to the root of the scraper, one end of the coil spring is connected to the fixed shaft, and the other end is connected to the scraper after bypassing the rotating shaft.

[0018] Furthermore, the scraper is arched upward, and the blade is inclined downward.

[0019] Furthermore, the mud scraping mechanism is arranged below the electromagnet.

[0020] In a second aspect, the present application provides a method for using the sludge plate-frame dewatering machine as described in the first aspect, wherein after squeezing the sludge into a mud cake, the plates and frames are pulled apart so that the magnetic blocks that attract and fix each other on adjacent plates and frames lose the magnetic force constraint of opposite sex attraction at least once. The method utilizes the magnetic force of the magnetic blocks and the resilience of the filter cloth to make it easier to separate the mud cake from the filter cloth.

[0021] The beneficial effects of the present invention are as follows: the present invention utilizes the magnetic force of opposite sex attraction to deform the filter cloth part when the plate frame is pulled apart, increases the mesh of the filter cloth, and tilts the side cloth layer relative to the mud cake, which is conducive to peeling off the mud cake, and continues to increase the distance between the plate frame. At the moment when the magnetic block loses the magnetic force constraint of opposite sex attraction, the pulled filter cloth rebounds to the plate frame wrapped by it, and can shake off the tightly adhered mud blocks. While realizing automatic mud unloading, the present invention makes it difficult for the sludge to block the mesh of the filter cloth, which is conducive to increasing the number of times the filter cloth is used before replacement and reducing the situation of manual mud shoveling.

[0022] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures particularly pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the plate frame and filter cloth used in a general sludge plate and frame dewatering machine.

[0024] Figure 2 It is a schematic diagram of the overall structure of a sludge plate and frame dewatering machine provided in an embodiment of the present application.

[0025] Figure 3 It is a schematic diagram of the sludge unloading principle of a sludge plate and frame dewatering machine provided in an embodiment of the present application.

[0026] Figure 4 This is a front view of the distribution position of the magnetic blocks on the side cloth layer provided in an embodiment of the present application.

[0027] Figure 5 This is one of the side cross-sectional views of the distribution positions of magnetic blocks on adjacent filter cloths provided in an embodiment of the present application.

[0028] Figure 6 This is the second lateral cross-sectional view of the distribution position of magnetic blocks on adjacent filter cloths provided in an embodiment of the present application.

[0029] Figure 7 It is a schematic diagram of the shape of the magnetic block provided in the embodiment of the present application.

[0030] Figure 8 It is a structural schematic diagram of the auxiliary mud unloading mechanism provided in an embodiment of the present application.

[0031] Fig. 9 It is a schematic diagram of the working status of the auxiliary mud unloading mechanism provided in an embodiment of the present application.

[0032] Figure numerals: 1. magnetic block; 2. auxiliary mud unloading mechanism; 21. telescopic arm; 22. electromagnet; 23. mounting plate; 231. fixed shaft; 232. rotating shaft; 24. scraper; 25. coil spring; 29. ​​suspension platform; 5. conveyor belt; 6. mud cake; 7. frame pulling mechanism; 8. plate frame; 81. conveying through hole; 91. side cloth layer; 911. opening; 92. filter cartridge; 82. pit; 912. binding tape. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0034] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0035] Plate and frame dewatering machine is an important machine for reducing the moisture content of sludge, but the sludge dewatering system composed of plate and frame dewatering machine often requires a large amount of manpower to shovel sludge to maintain operation, which is time-consuming and labor-intensive, and brings great problems to the automatic operation of the sewage treatment plant.

[0036] For this purpose, refer to Figures 2 to 4 The embodiment of the present application provides a sludge plate and frame dewatering machine, including plate frames 8 arranged parallel to each other on a first track, the plate frames 8 are wrapped with filter cloth, a conveying through hole is provided in the middle of the plate frames 8, the filter cloth includes two side cloth layers 91 and a filter cartridge located in the conveying through hole, an opening 911 is provided in the middle of the side cloth layer 91, and both ends of the filter cartridge are connected to the opening 911 of a side cloth layer 91, the plate frame 8 is made of non-ferromagnetic material, and a magnetic block 1 is provided on the inward side of the side cloth layer 91. In two adjacent filter cloths, the magnetic blocks 1 on the two adjacent side cloth layers 91 are aligned with each other and have the same magnetic pole direction. Figure 3 The legend in the upper left corner shows the direction of the magnetic pole. Figure 3 , Figure 5 , Figure 6 , Figure 7 The filled side of the middle magnetic block 1 is the N pole, and the unfilled side is the S pole.

[0037] The side fabric layer 91 may be connected to the magnetic block 1 by sewing, bonding, etc.

[0038] Accordingly, an embodiment of the present application provides a method for using a sludge plate and frame dewatering machine: after squeezing the sludge into a mud cake 6, the plate frames 8 are pulled apart so that the magnetic blocks 1 that attract and fix each other on adjacent plate frames 8 lose the magnetic constraint of oppositely charged particles at least once.

[0039] After the plates and frames of the sludge plate and frame dewatering machine provided in the embodiment of the present application are densely arranged and pressed, the magnetic blocks 1 on the two adjacent side cloth layers 91 are attracted to each other by opposite charges, and the two adjacent side cloth layers 91 are partially attached, and the unattached parts are filled with sludge, and a mud cake 6 is formed after squeezing. Figure 3 After the pressing is completed, the plate frame 8 is generally opened by the frame-drawing mechanism 7 of the sludge plate frame dewatering machine. This is the prior art, and the present application does not improve the frame-drawing mechanism and does not elaborate on it. Next, the mud unloading function in the process of opening the plate frame 8 is analyzed in detail.

[0040] When two adjacent plate frames 8 are gradually pulled apart, the filter cloth moves with the plate frames 8, but the magnetic block 1 is still attracted to the magnetic block 1 of the adjacent side cloth layer 91, the filter cloth will be stretched open, and the mesh gap of the filter cloth will increase, which is conducive to the separation of the mud cake 6 from the filter cloth.

[0041] The side fabric layer 91 is pulled, and the edge moves with the plate frame 8, but the magnetic block 1 is supported by the next plate frame (the next one in sequence when the frame is pulled). Figure 2 If the filter cloth (the one on the left side is seen in the figure) is torn, the side cloth layer 91 will become unable to remain parallel to the mud cake 6, and the mud cake 6 will be gradually peeled off.

[0042] The distance between two adjacent plate frames 8 continues to increase, and the pulled side cloth layer 91 gradually accumulates elastic force. When the elastic force is greater than the magnetic force, the magnetic block loses the magnetic constraint of opposite charges attracting each other, and the side cloth layer 91 rebounds at the moment of separation, which can shake off the stubborn sludge on the filter cloth.

[0043] If the speed of opening the plate frame is too slow, the filter cloth will be in a deformed state for a long time, which will reduce the service life of the filter cloth; if the speed of opening the plate frame is too fast, the rebound force of the filter cloth cannot be fully exerted. Preferably, the speed of opening the plate frame is 10cm / s~25cm / s, which has a good shock effect, causes less damage to the filter cloth, and can also take into account production efficiency.

[0044] In some embodiments, the plate frame can be repeatedly opened and closed after one pressing, so that the magnetic blocks between the filter cloths are repeatedly attracted and separated, resulting in multiple vibrations to shake off the mud cake.

[0045] In a more preferred embodiment, the sludge plate and frame dewatering machine also includes an auxiliary mud unloading mechanism 2 running on a second track, the second track is parallel to the first track, the auxiliary mud unloading mechanism 2 includes a suspension platform 29, the suspension platform 29 is provided with at least one pair of vertically downward telescopic arms 21, and the telescopic arms 21 are provided with electromagnets 22. The electromagnets 22 on the paired telescopic arms 21 are aligned with each other and separated, and the distance between them is greater than the thickness of a plate frame 8.

[0046] Correspondingly, the method of using the sludge plate and frame dewatering machine becomes: after squeezing the sludge into a mud cake, pull open the plate frame 8 so that the magnetic blocks 1 that attract and fix each other on adjacent plate frames 8 lose the magnetic constraint of opposite charges at least once; then drive the auxiliary mud unloading mechanism 2 to move to the top of the plate frame 8, extend the telescopic arm 21 downward until the electromagnet 22 descends to the position aligned with the magnetic block 1, and loads the coil of the electromagnet 22 with different current directions, so that the electromagnet 22 changes the magnetic pole direction multiple times (for example, 2 times / second to 50 times / second) in a short period of time, thereby continuously attracting and bouncing off the magnetic block 1 on the side cloth layer 91, which is conducive to shaking off the mud blocks with strong adhesion.

[0047] Some new sludge plate-frame dewatering machines in the prior art also have a second track and an auxiliary mud unloading mechanism, but the auxiliary mud unloading mechanism usually uses a water gun to spray the filter cloth, and the cleaning water will eventually fall on the conveyor belt 5 of the sludge plate-frame dewatering machine to convey the mud cake, which invisibly increases the water content of the mud cake; there are also existing auxiliary mud unloading mechanisms that use a high-pressure air gun for cleaning. Although the mud can be sprayed off, the high-pressure gas can easily impact the mud debris into the mesh embedded in the filter cloth, which is not conducive to the next round of squeezing and mud unloading. The embodiment of the present application will not wet the filter cloth and the conveyor belt 5, and the mud unloading can be more thorough.

[0048] Preferably, the telescopic arm 21 is also provided with a scraping mechanism, which includes a scraper 24, a coil spring 25 and a mounting plate 23 connected to the telescopic arm 21. The mounting plate 23 is provided with a fixed shaft 231 and a freely rotatable shaft 232. The shaft 232 is radially connected to the root of the scraper 24. One end of the coil spring 25 is connected to the fixed shaft 231, and the other end is connected to the scraper 24 after bypassing the shaft 232. The elastic force of the coil spring 25 can be used to adaptively adjust the relative angle between the scraper 24 and the mounting plate 23. The scraper 24 automatically follows and compensates to ensure that the blade is in close contact with the filter cloth, thereby achieving a good scraping effect, and can scrape the mud along the filter cloth to clean it up without damaging the filter cloth.

[0049] More preferably, the scraper 24 is arched upwards, and the blade is tilted downwards. The scraping action is to scrape from top to bottom, which is conducive to the scraped mud blocks falling quickly to the conveyor belt 5, reducing the accumulation of mud blocks on the blade. The material of the scraper 24 is preferably a non-ferromagnetic material, such as polyurethane.

[0050] Reference Fig. 9, the scraping mechanism is arranged below the electromagnet 22. The method of using the sludge plate-frame dewatering machine is changed to: after squeezing the sludge into a mud cake, pull apart the plate frame 8, so that the mutually attracted and fixed magnetic blocks 1 on the adjacent plate frames 8 lose the magnetic force constraint of opposite sex attraction at least once; then drive the auxiliary mud unloading mechanism 2 to move above the plate frame 8, extend the telescopic arm 21 downward, and make the scraper 24 scrape off the mud blocks on the filter cloth; and, every time the electromagnet 22 descends to the position aligned with the magnetic block 1, load the coil of the electromagnet 22 with different current directions, so that the electromagnet 22 changes the direction of the magnetic pole several times in a short time, thereby continuously attracting and bouncing off the magnetic block 1 on the side cloth layer 91. The entire mud unloading process actually becomes: first, use the rebound of the filter cloth when the adjacent side cloth layers 91 are separated to shake off the large pieces of mud cake, and then use the scraper 24 to scrape off the mud blocks still adhering to the filter cloth, and the electromagnet 22 repeatedly attracts and bounces off the magnetic block 1 to shake off the remaining mud debris.

[0051] In some embodiments, Figure 5 As shown in FIG. 1 , on the same filter cloth, the positions of the magnetic blocks 1 on the two side cloth layers 91 do not overlap. In other embodiments, such as Figure 6 As shown, on the same filter cloth, the magnetic poles of the magnetic blocks 1 on the two side cloth layers 91 are in opposite directions.

[0052] In fact, the plate-frame dewatering machine used for sludge dewatering is a large plate-frame dewatering machine, and the plate frame 8 is thick enough; and during squeezing, the adjacent side cloth layers 91 on two adjacent filter cloths are closer than the two side cloth layers 91 on the same filter cloth, and there is no need to consider the problem of the magnetic blocks 1 on the same filter cloth attracting each other. In a preferred embodiment, on the same filter cloth, the positions of the magnetic blocks 1 on the two side cloth layers 91 overlap and the magnetic poles are in the same direction. In this way, it is more convenient to set the position of the electromagnet 22, and it is easier to set the automatic working action of the telescopic arm 21 and the electromagnet 22.

[0053] Reference Figure 3 , the present invention actually sacrifices a small amount of filter cloth volume to accommodate sludge. Preferably, a plurality of magnetic blocks 1 are arranged on a single side cloth layer 91, and the projection area of ​​a single magnetic block 1 on the plate frame 8 is less than 2% of the area of ​​the plate frame 8, preferably less than 1%; on a single side cloth layer 91, the total projection area of ​​all magnetic blocks 1 on the plate frame 8 is less than 8% of the area of ​​the plate frame 8, ensuring the filling amount of the filter cloth filled with fluid sludge.

[0054] On the single side layer 91, multiple magnetic blocks 1 are distributed in rows and columns, the connection line of the magnetic blocks 1 in the same row is parallel to the horizontal plane, and the connection line of the magnetic blocks 1 in the same column is perpendicular to the horizontal plane and does not pass through the opening 911. This distribution is conducive to the smooth operation of the auxiliary mud unloading mechanism 2 from top to bottom. For specific distribution examples, please refer to Figure 4 , the magnetic blocks 1 can form a rectangular array and be dispersed as much as possible.

[0055] The shape of the magnetic block 1 is preferably not designed to be strip-shaped, which is not conducive to the rapid filling of the filter cloth with fluid sludge. Figure 7 The magnetic block 1 is in the shape of a cone, such as a prism, a frustum, preferably a truncated cone, with a side with a larger bottom area connected to the side cloth layer 91, and a side with a smaller bottom area facing the plate frame 8, which is conducive to the rapid filling of the filter cloth with fluid sludge before squeezing, and has a better shaking effect when unloading the sludge.

[0056] The invention can realize full-automatic mud unloading, and can reduce the labor intensity of workers; it can also make the filter cloth be used more times before replacement, reduce the frequency of filter cloth replacement, and improve the mud unloading efficiency.

[0057] In the description of this specification, the description with reference to the terms "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0058] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A sludge plate-frame dewatering machine, comprising plate frames (8) arranged parallel to each other on a first track, the plate frames (8) being wrapped with filter cloth, a conveying through hole being provided in the middle of the plate frames (8), the filter cloth comprising two side cloth layers (91) and a filter cartridge located in the conveying through hole, an opening (911) being provided in the middle of the side cloth layer (91), and two ends of the filter cartridge being respectively connected to the opening (911) of the side cloth layer (91), characterized in that: The plate frame (8) is made of non-ferromagnetic material, the side cloth layer (91) is elastic, and a magnetic block (1) is provided on an inward side of the side cloth layer (91). In two adjacent filter cloths, the magnetic blocks (1) on two adjacent side cloth layers (91) are aligned with each other and have the same magnetic pole direction. After the plate frame is pressed, the magnetic blocks on the two adjacent side cloth layers are attracted to each other with opposite polarities so that the two adjacent side cloth layers are partially attached. On the same filter cloth, the magnetic blocks (1) on the two side cloth layers (91) are overlapped in position and have the same magnetic pole direction. The sludge plate-frame dewatering machine further comprises an auxiliary mud unloading mechanism (2) running on a second track, the second track being parallel to the first track, the auxiliary mud unloading mechanism (2) comprising a suspension platform (29), the suspension platform (29) being provided with at least one pair of telescopic arms (21) extending vertically downward, the telescopic arms (21) being provided with electromagnets (22), the electromagnets (22) on the paired telescopic arms (21) being aligned with each other and spaced apart, the distance between them being greater than the thickness of one of the plate frames (8); The telescopic arm (21) is also provided with a scraping mechanism, comprising a scraper (24), a coil spring (25) and a mounting plate (23) connected to the telescopic arm (21); a fixed shaft (231) and a freely rotatable rotating shaft (232) are provided on the mounting plate (23); the rotating shaft (232) is radially connected to the root of the scraper (24); one end of the coil spring (25) is connected to the fixed shaft (231), and the other end is connected to the scraper (24) after bypassing the rotating shaft (232).

2. The sludge plate-frame dewatering machine according to claim 1, characterized in that: A plurality of the magnetic blocks (1) are arranged on a single side cloth layer (91), and a projection area of ​​a single magnetic block (1) on the plate frame (8) is less than 2% of an area of ​​the plate frame (8); and a total projection area of ​​all the magnetic blocks (1) on the plate frame (8) on a single side cloth layer (91) is less than 8% of an area of ​​the plate frame (8).

3. The sludge plate-frame dewatering machine according to claim 2, characterized in that: On the single side fabric layer (91), the plurality of magnetic blocks (1) are distributed in rows and columns, the connection line of the magnetic blocks (1) in the same row is parallel to the horizontal plane, and the connection line of the magnetic blocks (1) in the same column is perpendicular to the horizontal plane and does not pass through the opening (911).

4. The sludge plate-frame dewatering machine according to claim 1, characterized in that: The magnetic block (1) is in the shape of a cone, with a side with a larger bottom area connected to the side fabric layer (91) and a side with a smaller bottom area facing the plate frame (8).

5. The sludge plate-frame dewatering machine according to claim 1, characterized in that: The scraper (24) is arched upward, and the blade is inclined downward.

6. The sludge plate-frame dewatering machine according to claim 1, characterized in that: The mud scraping mechanism is arranged below the electromagnet (22).

7. A method for using the sludge plate-frame dewatering machine according to any one of claims 1 to 6, characterized in that: After the sludge is squeezed into a sludge cake, the plate frames (8) are pulled apart, so that the magnetic blocks (1) on adjacent plate frames (8) that are attracted and fixed to each other lose the magnetic restraint of oppositely charged particles at least once.

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