Sludge dewatering process and device

Abstract

The invention relates to the field of sludge dewatering, and discloses a sludge dewatering process and device.The sludge dewatering process comprises the steps that firstly, sludge of all factories enters a concentration tank, and the water content is reduced to 97% through gravity settling; step 2, pumping the concentrated sludge into a conditioning tank, adding an agent to improve the dehydration performance, combining an agent A and an agent B, adding the agent A and the agent B in sequence, and stirring the agent A and the agent B; 3, the conditioned sludge is subjected to high-pressure dehydration through a plate-and-frame filter press; and 4, conveying the dehydrated mud cake to a mud storage hopper, and then conveying the mud cake to a terminal disposal plant. A low-temperature drying and coupled incineration process is adopted, the volume of drying and incineration is reduced into a small amount of ash, and the quality of a mud cake is improved by a medicament; drying heat energy comes from boiler steam in a plant, harmful components are reduced, and safety is improved; through preliminary dehydration, the driving mechanism drives the extruding mechanism to dynamically extrude and reduce the water content, three states of the driving mechanism are adaptive to the flow, and the scraper and the blade automatically clean and separate mud, so that the labor and health risks are reduced, and the unification of environment and economic benefits is realized.

Description

Technical Field

[0001] This invention relates to the field of sludge dewatering technology, and more specifically, to a sludge dewatering process and apparatus. Background Technology

[0002] Sludge dewatering refers to the process of concentrating and drying sludge with a high water content (usually 95% to 99%) generated during wastewater treatment through physical or chemical methods, reducing its water content to 60% to 80%, thereby reducing its volume and facilitating transportation and subsequent disposal (such as landfill, incineration, or composting).

[0003] In the current sludge dewatering process, the filter press stage generally relies on pump pressure as the sole driving force to inject sludge into the filter press chamber. Due to the limitation of the single pump pressure working method, the sludge cake still retains a considerable amount of moisture, making it difficult to further reduce the moisture content. Summary of the Invention

[0004] This invention provides a sludge dewatering process and apparatus, which solves the technical problems of utilization rate and treatment thoroughness in related technologies.

[0005] This invention provides a sludge dewatering process, comprising the following steps: Step 1: The sludge from each plant first enters the thickening tank, where the moisture content is reduced to 97% through gravity settling. Step 2: The concentrated sludge is pumped into the conditioning tank, and chemicals are added to improve the dewatering performance. A combination of agent A and agent B is used, and the chemicals are added in sequence and stirred. Step 3: After conditioning, the sludge undergoes high-pressure dewatering using a plate and frame filter press. Step 4: The dehydrated mud cake is transported to the mud storage hopper and then to the terminal treatment plant. Mud cake with a moisture content of 45% can be temporarily stored, while mud cake with a higher moisture content needs to be further processed. Mud cake with a moisture content of 60% needs to be transported to the power plant for low-temperature drying. Step 5: The sludge with high moisture content that is transported to the power plant is processed through a belt drying line with steam as the heat source to reduce its moisture content to below 40% in order to meet the fuel requirements for subsequent incineration. Step Six: The dried sludge is mixed with coal in a certain proportion and sent to a boiler for incineration. The steam generated from incineration is used for heating and power generation to achieve energy recovery, while the incineration residue is transported off-site as raw material for the production of building materials.

[0006] A sludge dewatering process, comprising agent A: 10-20% hydrophobic multinucleated nano-flocculator materials, such as kaolin, fly ash, sepiolite, etc., used to construct the framework structure; 30-35% nano-chelated iron solution, composed of chelating agents (such as ethylenediaminetetraacetic acid, aminotriacetic acid) and iron salts (ferric sulfate / ferrous sulfate) in a molar ratio of 3:2-7:3, acting as charge neutralization and flocculation nuclei; and 10-15% polymeric metal complexes, such as aluminum silicate, aluminum chloride, etc., to enhance the flocculation effect. Dispersant 5–10%: such as sodium polyacrylate, cetyltrimethylammonium bromide, to ensure uniform dispersion of components; pH adjuster 2–5%: such as sodium hydroxide, to adjust the acidity or alkalinity of the product; Deionized water: balance; Preparation method of agent A: First, mechanically stir the hydrophobic material with deionized water until homogeneous; Add dispersant, nano-chelated iron solution, and polymeric metal complex sequentially, and react in a water bath at 40–50°C for 45 minutes; Finally, add the pH adjuster and stir until the system is homogeneous to obtain the finished product; Agent B includes 5–10% cationic surfactants, such as hexadecyltrimethylammonium bromide, used to disrupt cell membranes; 10–20% polyphase amine polymers, such as polydimethyldiallyl ammonium chloride, which act as adsorption bridges and decolloids; 2–5% persulfate, such as sodium persulfate, which acts as an oxidant to break down organic matter; 1–3% pH adjuster, such as sodium hydroxide, to stabilize the pH of the system; and deionized water: balance.

[0007] Preparation method: First, mix the pH adjuster with deionized water to prepare a buffer matrix solution; An oxidation-activated system was prepared by adding persulfate to the matrix solution and stirring at a constant speed. The cationic surfactant and multiphase amine polymer are added sequentially, and the mixture is dispersed with ultrasonic assistance for minutes to obtain the finished product.

[0008] As a further optimization of the present invention, it includes a frame, a thrust plate, a pressing plate, a multi-layer filter plate, and a filter cloth disposed between the filter plates. A hydraulic cylinder for driving the pressing plate to move is mounted on the frame, and a filter frame is fitted around the outer periphery of the filter plate. The filter frame is equipped with several sets of extrusion mechanisms, which are used in conjunction with a drive mechanism. The extrusion mechanism includes blades for dividing the mud cake, the drive mechanism includes a raised area, and the drive mechanism has a first position state, a second position state, and a third position state. In the first position state, multiple filter plates are stacked to process sludge; In the second position state, the extrusion mechanism is driven by the drive mechanism to extrude the mud cake. In the third position, the squeezing mechanism is adjusted by the drive mechanism to the corresponding mating protrusion area so that the squeezing mechanism reciprocates to remove the mud cake when the filter plate opens and closes.

[0009] As a further optimization of the present invention, the extrusion mechanism also includes a scraper, a pull rod, a transmission rod, and a return member. The scraper is slidably disposed inside the filter frame and is fixedly connected to the blade. One end of the pull rod is fixedly connected to the scraper, and the other end slides out of the filter frame and is reversibly connected to the filter frame through the return member. The transmission rod is rotatably connected to the pull rod and is adapted to the protruding area.

[0010] As a further optimization of the present invention, the recovery component includes a connecting block and a spring. The spring is movably sleeved on the outer periphery of the pull rod. One end of the spring is fixedly connected to the filter frame, and the other end is connected to the pull rod through the connecting block.

[0011] As a further optimization of the present invention, the protruding area includes a rotating rod and multiple protrusions, with the multiple protrusions installed on the rotating rod at equal intervals.

[0012] As a further optimization of the present invention, the drive mechanism also includes a drive motor, a mounting bracket, a linear actuator, and a mounting plate. The drive motor is mounted on the mounting plate and is connected to the rotating rod shaft. The linear actuator is mounted on the frame through the mounting bracket, and the output end of the linear actuator is fixedly connected to the mounting plate.

[0013] As a further optimization of the present invention, a guide rod is installed on the mounting bracket, and one end of the guide rod slides through the mounting plate.

[0014] As a further optimization of the present invention, an opening is provided on the scraper located in the middle area of ​​the non-filter box for sludge to pass through.

[0015] As a further optimization of the present invention, an inclined scraping portion is formed on the scraper.

[0016] The beneficial effects of this invention are as follows: 1. The novel sludge conditioner does not introduce solid substances such as lime during sludge treatment, resulting in significant volume reduction advantages. The amount of reagent required is greatly reduced, decreasing reagent procurement costs and storage space, and significantly lowering sludge transportation and final disposal costs, bringing substantial economic benefits to production operations. 2. In the traditional "iron salt + lime" conditioning system, the use of lime can lead to severe calcium scaling problems. During equipment operation, calcium ions in lime easily combine with other substances in the sludge to form hard calcium scale, which adheres to the surface of the filter cloth and filter plates, affecting the sludge dewatering effect, increasing equipment wear, and shortening the equipment's service life. By using a new type of sludge conditioner, the addition of lime is eliminated, blocking the introduction of calcium at the source, thus effectively solving the calcium scaling problem on the filter cloth and filter plates.

[0017] 3. After being treated with new agents, the sludge is then processed using a "low-temperature drying + coupled incineration" process, which can achieve significant environmental and economic benefits. This route completely eliminates pathogens through high-temperature incineration, achieving harmlessness; and through drying and incineration, the sludge is reduced to a small amount of ash residue, fundamentally solving the disposal problem. At the same time, the use of new agents replaces the addition of inorganic solid substances such as lime in the traditional process, effectively preserving the organic components of the sludge and improving the quality of the sludge cake, significantly increasing its calorific value and significantly reducing its sulfur content. This not only makes the sludge a high-quality clean fuel, replacing part of the coal and directly reducing energy costs, but also reduces the corrosion of subsequent incineration equipment and the load on flue gas treatment.

[0018] 4. This further expands resource utilization pathways and creates circular economy value. The heat energy required for drying comes from boiler steam within the plant, forming a closed-loop energy system. The phosphorus-rich ash residue after incineration can be used as a high-quality raw material for phosphorus recovery or green building materials. The new conditioning process does not produce excessively acidic or alkaline waste, effectively preventing soil structure damage and groundwater pollution caused by pesticide residues. The pH value of the effluent and sludge cake from the plate and frame sludge treatment plant is above 5, without increasing the treatment load on the wastewater treatment plant. Besides incineration, the treated sludge cake can also be utilized through soil conditioners, landscaping substrates, composting, etc., which better aligns with the concepts of environmental protection and sustainable development. The new sludge conditioner improves the safety and applicability of the sludge cake, enabling its wider application in various resource utilization pathways while reducing potential environmental hazards. The new conditioner does not introduce substances such as lime that may damage soil structure, making the treated sludge cake more suitable as a soil conditioner. The organic matter and nutrients in the sludge cake can improve soil structure, increase soil fertility, and promote plant growth, while reducing negative environmental impacts. The reduction of harmful sulfur and chlorine components enhances its utilization safety. Ultimately, this model achieves a balance between environmental and economic benefits by realizing the complete and safe disposal of sludge, saving energy and reducing consumption, recycling resources, and lowering the overall cost.

[0019] 5. The hydraulic cylinder drives the pressing plate to form a filter press chamber, completing the initial dewatering of the sludge. Then, the drive mechanism drives the extrusion mechanism to operate, and the blades and scrapers dynamically extrude the sludge cake to further squeeze out the internal bound water, ultimately reducing the moisture content of the sludge cake to meet the moisture content requirements of the incineration fuel, laying the foundation for subsequent resource utilization.

[0020] 6. The drive mechanism has three position states. During the filter plate opening and closing stage, the protrusion on the rotating rod pushes the transmission rod, which drives the scraper to move back and forth. In conjunction with the inclined scraping part, it can scrape off the residual mud cake on the filter cloth. At the same time, the blades divide large mud cakes into smaller pieces, avoiding the problem of manual cleaning caused by mud cakes sticking to the filter cloth. Compared with traditional devices that require manual scraping of mud cakes, it can reduce the amount of manual operation, reduce the labor intensity of workers and the health risks of contact with sludge. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of a sludge dewatering device proposed in this invention.

[0022] Figure 2 This is a schematic diagram of the sludge dewatering device proposed in this invention from another perspective.

[0023] Figure 3 This is a schematic diagram of the internal structure of the filter frame in a sludge dewatering device proposed in this invention.

[0024] Figure 4 This is a schematic diagram of the protrusion structure in a sludge dewatering device proposed in this invention.

[0025] Figure 5 This is a schematic diagram of the filter plate structure in a sludge dewatering device proposed in this invention.

[0026] In the picture: 1. Rack; 2. Thrust plate; 3. Pressure plate; 4. Filter plate; 5. Filter cloth; 6. Hydraulic cylinder; 7. Extrusion mechanism; 71. Blade; 72. Scraper; 721. Through port; 73. Tie rod; 74. Connecting block; 75. Spring; 76. Transmission rod; 8. Drive mechanism; 81. Rotating rod; 82. Protrusion; 83. Drive motor; 84. Mounting bracket; 85. Linear actuator; 86. Mounting plate; 87. Guide rod; 9. Filter frame. Detailed Implementation

[0027] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples. Example 1

[0028] The sludge dewatering process described in this embodiment of the invention includes the following steps: Step 1: The sludge from each plant first enters the thickening tank, where the moisture content is reduced to 97% through gravity settling. Step 2: The concentrated sludge is pumped into the conditioning tank, and chemicals are added to improve the dewatering performance. A combination of agent A and agent B is used, and the chemicals are added in sequence and stirred. Step 3: After conditioning, the sludge undergoes high-pressure dewatering using a plate and frame filter press. Step 4: The dehydrated mud cake is transported to the mud storage hopper and then to the terminal treatment plant. Mud cake with a moisture content of 45% can be temporarily stored, while mud cake with a higher moisture content needs to be further processed. Mud cake with a moisture content of 60% needs to be transported to the power plant for low-temperature drying. Step 5: The sludge with high moisture content that is transported to the power plant is processed through a belt drying line with steam as the heat source to reduce its moisture content to below 40% in order to meet the fuel requirements for subsequent incineration. Step Six: The dried sludge is mixed with coal in a certain proportion and sent to a boiler for incineration. The steam generated from incineration is used for heating and power generation to achieve energy recovery, while the incineration residue is transported off-site as raw material for the production of building materials.

[0029] Agent A includes: 10–20% hydrophobic multinucleated nano-flocculators, such as kaolin, fly ash, and sepiolite, used to construct the skeletal structure; 30–35% nano-chelated iron solution, composed of chelating agents such as ethylenediaminetetraacetic acid and aminotriacetic acid, and ferric sulfate / ferrous sulfate in a molar ratio of 3:2–7:3, which acts as a charge neutralizer and flocculation nucleus; and 10–15% polymeric metal complexes, such as aluminum silicate and aluminum chloride, to enhance the flocculation effect. Dispersant 5–10%: such as sodium polyacrylate, cetyltrimethylammonium bromide, to ensure uniform dispersion of components; pH adjuster 2–5%: such as sodium hydroxide, to adjust the acidity or alkalinity of the product; Deionized water: balance; Preparation method of agent A: First, mechanically stir the hydrophobic material with deionized water until homogeneous; Add dispersant, nano-chelated iron solution, and polymeric metal complex sequentially, and react in a water bath at 40–50°C for 45 minutes; Finally, add the pH adjuster and stir until the system is homogeneous to obtain the finished product; Agent B includes 5–10% cationic surfactants, such as hexadecyltrimethylammonium bromide, used to disrupt cell membranes; 10–20% polyphase amine polymers, such as polydimethyldiallyl ammonium chloride, which act as adsorption bridges and decolloids; 2–5% persulfate, such as sodium persulfate, which acts as an oxidant to break down organic matter; 1–3% pH adjuster, such as sodium hydroxide, to stabilize the pH of the system; and deionized water: balance.

[0030] Preparation method: First, mix the pH adjuster with deionized water to prepare a buffer matrix solution; An oxidation-activated system was prepared by adding persulfate to the matrix solution and stirring at a constant speed. The cationic surfactant and multiphase amine polymer are added sequentially, and the mixture is dispersed with ultrasonic assistance for 30 minutes to obtain the finished product. Example 2

[0031] Based on Example 1, such as Figures 1 to 3 and Figure 5 As shown, a sludge dewatering device is a plate and frame filter press, including a frame 1, a thrust plate 2, a pressing plate 3, a multi-layer filter plate 4 and a filter cloth 5 disposed between the filter plates 4, a hydraulic cylinder 6 that drives the pressing plate 3 to move is mounted on the frame 1, and a filter frame 9 is fitted around the outer periphery of the filter plate 4. The filter frame 9 is equipped with several sets of extrusion mechanisms 7, and the extrusion mechanisms 7 are used in conjunction with a drive mechanism 8; The extrusion mechanism 7 includes a blade 71 for dividing the mud cake, the drive mechanism 8 includes a raised area, and the drive mechanism 8 has a first position state, a second position state, and a third position state. In the first position state, the multi-layer filter plates 4 are stacked to process sludge; In the second position state, the extrusion mechanism 7 is driven by the drive mechanism 8 to extrude the mud cake. In the third position, the squeezing mechanism 7 is adjusted by the driving mechanism 8 to the corresponding mating protrusion area so that the squeezing mechanism 7 reciprocates to remove the mud cake when the filter plate 4 is opened and closed.

[0032] The thrust plate 2 is fixedly installed at one end of the frame 1. It plays a positioning and supporting role when the filter plates 4 are stacked, restricts the axial displacement of the filter plates 4, and ensures that the multi-layer filter plates 4 can be tightly fitted to form a closed filter chamber, preventing sludge from leaking from the ends of the filter plates 4 during the filter pressing process.

[0033] Driven by the hydraulic cylinder 6, the clamping plate 3 can move along the frame 1. Its function is to press the multi-layer filter plates 4 tightly before filtration, so that the filter plates 4 and the filter cloth 5 are closely attached to form a closed filter chamber. After filtration is completed, the filter plates 4 are loosened as the hydraulic cylinder 6 moves back, so that the filter plates 4 can be opened and closed and the sludge cake can be discharged. The filter cloth 5 is sandwiched between the filter plates 4. After the multi-layer filter plates 4 are stacked, multiple independent filter chambers are formed. The filter plates 4 are usually made of high-strength and corrosion-resistant materials and can withstand high pressure. The filter cloth 5 has good filtration performance, allowing water to pass through while trapping sludge solid particles. During the filtration process, the sludge is pumped into the filter chamber, and the water permeates through the filter cloth 5 to the drainage channel of the filter plate 4 and is discharged. The solid particles form a sludge cake in the filter chamber.

[0034] The squeezing mechanism 7 processes the mud cake during and after the filtration process. During the filtration process, it can assist in squeezing the mud cake to remove more water. After the filtration process, the blade 71 can divide the larger mud cake into smaller pieces, which facilitates the discharge of the mud cake and subsequent processing. At the same time, it can work with the scraper 72 to remove the mud cake remaining on the filter cloth 5.

[0035] First position: Multi-layer filter plates 4 stacked for sludge treatment: At this time, the drive mechanism 8 is in the initial position and no driving force is applied to the squeezing mechanism 7. The squeezing mechanism 7 remains stationary and does not affect the stacking of the filter plates 4 and the formation of the filter chamber. The multi-layer filter plates 4 are tightly fitted under the action of the pressing plate 3. The sludge is pumped into the filter chamber for pressure filtration and dewatering. Water is discharged through the filter cloth 5, and solid particles form a sludge cake in the filter chamber. The core of this state is to ensure that the filter chamber is sealed, providing a stable space for sludge pressure filtration and ensuring the normal operation of the dewatering process.

[0036] Second position state: The squeezing mechanism 7 is driven by the driving mechanism 8 to squeeze the sludge cake: After the sludge is initially filtered to form a sludge cake, the driving mechanism 8 is activated, applying a pulling force to the squeezing mechanism 7 through the non-protruding area. Under the action of the driving force, the squeezing mechanism 7 moves towards the sludge cake and further squeezes the sludge cake. At this time, the sludge cake is subjected to the dual action of static pressure from the filter plate 4 and dynamic pressure from the squeezing mechanism 7, which can overcome the adsorption force between the water inside the sludge cake and the solid particles, squeeze out more residual water, and further reduce the moisture content of the sludge cake. The effect of this state is to improve the dewatering depth and make the sludge cake moisture content even lower, meeting the requirements of subsequent treatment.

[0037] Third position: The squeezing mechanism 7, adjusted by the drive mechanism 8 to align with the raised area, reciprocates as the filter plate 4 opens and closes to remove the sludge cake. After filtration is complete, the hydraulic cylinder 6 drives the pressing plate 3 back, and the filter plate 4 begins to open and close. At this time, the drive mechanism 8 adjusts its position so that the raised area matches the squeezing mechanism 7. As the filter plate 4 opens and closes, the raised area pushes the squeezing mechanism 7 to reciprocate. The scraper 72 on the squeezing mechanism 7 can scrape off the sludge cake remaining on the filter cloth 5, while the blade 71 can divide the sludge cake into small pieces, making it easier for the sludge cake to fall out of the filter chamber and be discharged. The effect of this state is to achieve automatic removal and discharge of the sludge cake, reduce manual intervention, improve the working efficiency of the device, and reduce the sludge cake residue clogging the filter cloth 5, ensuring the normal operation of subsequent filtration processes.

[0038] like Figure 3 and Figure 4 As shown, the extrusion mechanism 7 also includes a scraper 72, a pull rod 73, a transmission rod 76, and a return member. The scraper 72 is slidably disposed inside the filter frame 9 and is fixedly connected to the blade 71. One end of the pull rod 73 is fixedly connected to the scraper 72, and the other end slides out of the filter frame 9 and can be reconnected to the filter frame 9 through the return member. The transmission rod 76 is rotatably connected to the pull rod 73 and is adapted to the protruding area. An inclined scraping part is formed on the scraper 72.

[0039] The scraper 72 is used to contact the surface of the filter cloth 5 when the extrusion mechanism 7 is activated, and to scrape off the residual mud cake on the filter cloth 5 by sliding. Since the scraper 72 is fixedly connected to the blade 71, the scraper 72 can scrape off the mud cake at the same time as the blade 71 cuts the mud cake, ensuring that the surface of the filter cloth 5 is clean. The sliding setting of the scraper 72 allows it to adapt to the changes in the space inside the filter frame 9 and move flexibly under the drive of the drive mechanism 8 to ensure the scraping effect.

[0040] The function of the pull rod 73 is to transmit driving force, which transmits the power of the drive mechanism 8 to the scraper 72 and the blade 71, causing them to move inside the filter frame 9. The design of the pull rod 73 sliding out of the filter frame 9 facilitates connection with the external return component and the transmission component of the drive mechanism 8. At the same time, it can limit the movement direction of the scraper 72 to ensure that it slides along the set trajectory.

[0041] The function of the transmission rod 76 is to convert the rotation or movement of the protruding area of ​​the drive mechanism 8 into the linear movement of the pull rod 73. When the protruding area contacts the transmission rod 76, it pushes the transmission rod 76 to rotate around the connection point of the pull rod 73, thereby driving the pull rod 73 to move axially. Since the transmission rod 76 and the pull rod 73 are rotatably connected, it can adapt to the change of the movement trajectory of the protruding area, ensuring the smoothness of power transmission, realizing the power conversion and transmission between the drive mechanism 8 and the extrusion mechanism 7, so that the extrusion mechanism 7 can complete the extrusion and scraping of mud cake according to the action of the drive mechanism 8.

[0042] Specifically, the response component includes a connecting block 74 and a spring 75. The spring 75 is movably sleeved on the outer periphery of the pull rod 73. One end of the spring 75 is fixedly connected to the filter frame 9, and the other end is connected to the pull rod 73 through the connecting block 74.

[0043] The extrusion mechanism 7 is automatically reset by the elastic action of the spring 75.

[0044] like Figure 4 As shown, the protruding area includes a rotating rod 81 and multiple protrusions 82, which are installed on the rotating rod 81 at equal intervals.

[0045] When the pull rod 73 is pulled, the other sides of the outer periphery of the rotating rod 81 contact the transmission rod 76. Multiple protrusions 82 are installed at equal intervals on the rotating rod 81, which together form the raised area of ​​the drive mechanism 8. Its core function is to provide periodic driving force for the extrusion mechanism 7, so as to realize the reciprocating motion of the extrusion mechanism 7. When the drive mechanism 8 is working, the rotating rod 81 rotates under the drive of the drive motor 83. The protrusions 82 on the rotating rod 81 move in a circular motion with the rotating rod 81. When the protrusions 82 contact the transmission rod 76 of the extrusion mechanism 7, they will generate a radial thrust on the transmission rod 76, pushing the transmission rod 76 to rotate around the connection point of the pull rod 73, thereby driving the pull rod 73 to move axially, so that the scraper 72 and the blade 71 of the extrusion mechanism 7 move towards the mud cake. After the protrusions 82 have rotated past the transmission rod 76, the thrust of the protrusions 82 on the transmission rod 76 disappears. Under the action of the spring 75, the pull rod 73 drives the transmission rod 76 to return to the initial position, waiting for the push of the next protrusion 82.

[0046] like Figure 4 As shown, the drive mechanism 8 also includes a drive motor 83, a mounting bracket 84, a linear actuator 85, and a mounting plate 86. The drive motor 83 is mounted on the mounting plate 86 and is axially connected to the rotating rod 81. The linear actuator 85 is mounted on the frame 1 through the mounting bracket 84, and the output end of the linear actuator 85 is fixedly connected to the mounting plate 86.

[0047] The drive motor 83 is axially connected to the rotating rod 81 and fixed together on the mounting plate 86. The drive motor 83 can change the outer peripheral side that contacts the transmission rod 76. The mounting plate 86 is supported and driven by the linear actuator 85 via the mounting bracket 84. The linear actuator 85 is a hydraulic cylinder or a pneumatic cylinder.

[0048] Furthermore, in order to increase the stability of the movement of the mounting bracket 84, a guide rod 87 is installed on the mounting bracket 84, one end of the guide rod 87 sliding through the mounting plate 86.

[0049] Since the middle part of the filter plate 4 is usually filled with sludge pumped by the sludge pump, the width of the scraper 72 located in the middle is smaller than the sludge conveying port. The scraper 72 located in the non-middle area of ​​the filter frame 9 has an opening 721, which provides a flow channel for the sludge during the filter press process and prevents the scraper 72 from obstructing the distribution of sludge in the filter chamber. In the initial stage when the sludge is pumped into the filter chamber, the opening of the opening 721 allows the sludge to flow and diffuse in the filter chamber through the opening 721 during the pumping process, ensuring that the sludge can be evenly distributed in all areas of the filter chamber to form a sludge cake of uniform thickness.

[0050] The embodiments of the present invention have been described above, but the embodiments are not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the embodiments described above, all of which are within the protection scope of the embodiments described above.

Claims

1. A sludge dewatering process, characterized in that, Includes the following steps: Step 1: The sludge from each plant first enters the thickening tank, where the moisture content is reduced to 97% through gravity settling. Step 2: The concentrated sludge is pumped into the conditioning tank, and chemicals are added to improve the dewatering performance. A combination of agent A and agent B is used, and the chemicals are added in sequence and stirred. Step 3: After conditioning, the sludge undergoes high-pressure dewatering using a plate and frame filter press. Step 4: The dehydrated mud cake is transported to the mud storage hopper and then to the terminal treatment plant. Mud cake with a moisture content of 60% needs to be transported to the power plant for low-temperature drying treatment. Step 5: The sludge with high moisture content that is transported to the power plant is processed through a belt drying line with steam as the heat source to reduce its moisture content to below 40% in order to meet the fuel requirements for subsequent incineration. Step Six: The dried sludge is mixed with coal in a certain proportion and sent to a boiler for incineration. The steam generated from incineration is used for heating and power generation to achieve energy recovery, while the incineration residue is transported off-site as raw material for the production of building materials.

2. The sludge dewatering process according to claim 1, characterized in that: Agent A includes: 10–20% hydrophobic multinucleated nano-flocculator, 30–35% nano-chelated iron solution, 10–15% polymeric metal complex, 5–10% dispersant, 2–5% pH adjuster, and the remainder deionized water; Preparation method of agent A: First, mechanically stir the hydrophobic material with deionized water until homogeneous; Add dispersant, nano-chelated iron solution, and polymeric metal complex sequentially, and react in a water bath at 40–50°C for 45 minutes; Finally, add the pH adjuster and stir until the system is homogeneous to obtain the finished product; Agent B consists of 5–10% cationic surfactant, 10–20% multiphase amine polymer, 2–5% persulfate, 1–3% pH adjuster, and the remainder deionized water; Preparation method: First, mix the pH adjuster with deionized water to prepare a buffer matrix solution; An oxidation-activated system was prepared by adding persulfate to the matrix solution and stirring at a constant speed. The cationic surfactant and multiphase amine polymer are added sequentially, and the mixture is dispersed with ultrasonic assistance for 30 minutes to obtain the finished product.

3. A sludge dewatering apparatus based on claim 1 or 2, characterized in that, Includes a frame (1), a thrust plate (2), a clamping plate (3), a multi-layer filter plate (4) and a filter cloth (5) disposed between the filter plates (4). The frame (1) is equipped with a hydraulic cylinder (6) that drives the clamping plate (3) to move. The filter plate (4) is fitted with a filter frame (9) on its outer periphery. The filter frame (9) is equipped with several sets of extrusion mechanisms (7), and the extrusion mechanisms (7) are used in conjunction with a drive mechanism (8). The extrusion mechanism (7) includes a blade (71) for dividing the mud cake, the drive mechanism (8) includes a raised area, and the drive mechanism (8) has a first position state, a second position state and a third position state. In the first position state, the multi-layer filter plates (4) are stacked to process sludge; In the second position state, the extrusion mechanism (7) is driven by the drive mechanism (8) to extrude the mud cake. In the third position, the squeezing mechanism (7) is adjusted by the driving mechanism (8) to the corresponding mating protrusion area so that the squeezing mechanism (7) reciprocates to remove the mud cake when the filter plate (4) opens and closes.

4. The sludge dewatering device according to claim 3, characterized in that: The extrusion mechanism (7) also includes a scraper (72), a pull rod (73), a transmission rod (76), and a return member. The scraper (72) is slidably disposed inside the filter frame (9) and fixedly connected to the blade (71). One end of the pull rod (73) is fixedly connected to the scraper (72), and the other end slides out of the filter frame (9) and can be reconnected to the filter frame (9) through the return member. The transmission rod (76) is rotatably connected to the pull rod (73) and is adapted to the protruding area.

5. The sludge dewatering device according to claim 4, characterized in that: The response component includes a connecting block (74) and a spring (75). The spring (75) is movably sleeved on the outer periphery of the pull rod (73). One end of the spring (75) is fixedly connected to the filter frame (9), and the other end is connected to the pull rod (73) through the connecting block (74).

6. The sludge dewatering process and apparatus according to claim 4, characterized in that: The raised area includes a rotating rod (81) and multiple protrusions (82), which are installed on the rotating rod (81) at equal intervals.

7. A sludge dewatering device according to claim 6, characterized in that: The drive mechanism (8) also includes a drive motor (83), a mounting bracket (84), a linear actuator (85), and a mounting plate (86). The drive motor (83) is mounted on the mounting plate (86) and is axially connected to the rotating rod (81). The linear actuator (85) is mounted on the frame (1) through the mounting bracket (84), and the output end of the linear actuator (85) is fixedly connected to the mounting plate (86).

8. A sludge dewatering device according to claim 7, characterized in that: A guide rod (87) is mounted on the mounting bracket (84), and one end of the guide rod (87) slides through the mounting plate (86).

9. A sludge dewatering device according to claim 8, characterized in that: An opening (721) is provided on the scraper (72) located in the middle area of ​​the non-filter frame (9) for sludge to pass through.

10. A sludge dewatering device according to claim 9, characterized in that: An inclined scraping section is formed on the scraper (72).

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