Full-automatic multi-cleaning control method and system for plate-and-frame filter press

Abstract

The invention provides a full-automatic multi-cleaning control method and system for a plate-and-frame filter press. The method comprises the following sequentially executed steps: S1, a filter pressing procedure: filling fluorine-containing or sulfur-containing slurry into the filter press through a feeding pipeline, and pressing a filter plate for solid-liquid separation; s2, primary cleaning: after the filter pressing procedure is completed, purging the feeding pipeline for 0-5 minutes; s3, a mud unloading procedure: moving the filter plate through a plate pulling trolley to enable the filter cake to fall off, and completing mud unloading circulation; s4, secondary cleaning: after the sludge unloading procedure is completed, washing the feeding pipeline and the filter plate filter cloth for not less than 30 seconds by using high-pressure water; and S5, triple cleaning: after the secondary cleaning, performing deep circulating cleaning on each piece of filter cloth of the filter plate by using process water. Complete'one-button 'automatic operation from filter pressing and primary cleaning, mud unloading and secondary cleaning to triple cleaning is achieved, cleanliness of the filter press body and filter plates and filter cloth is guaranteed to the maximum extent, equipment reliability is greatly improved, and the service life is greatly prolonged.

Description

Technical Field

[0001] This application relates to the field of solid-liquid separation technology, and in particular to a fully automatic multi-cleaning control method and system for plate and frame filter presses. Background Technology

[0002] Filter presses are key pieces of equipment widely used in industries such as chemical, pharmaceutical, metallurgical, and environmental protection for solid-liquid separation. Traditional filter press operation largely relies on manual assistance, making fully automated operation difficult. In particular, the three main steps of filtration, sludge discharge, and washing are typically performed manually, with each step requiring separate operation. For example, sludge discharge requires manual removal of the filter cake; otherwise, the cake will adhere to the filter plates and cannot detach naturally. Furthermore, each process requires manual control of valves according to the established procedures. This operating mode suffers from low production efficiency, high labor intensity, and poor operational consistency, directly impacting filtration efficiency, filter cake quality, and system lifespan.

[0003] Although some filter presses have achieved partial automation, such as automatic plate unloading and automatic filtration, the integrated intelligent control of the entire work cycle remains a technical challenge to be solved.

[0004] This is mainly reflected in the following aspects: 1. Each actuator needs to operate according to different process requirements and different logical sequences; in particular, the setting of pre-action requirements, signal feedback verification, and the operation time of oil pumps and valves all need to be determined through extensive field practice. 2. Actuators such as pull-plate trolleys and cleaning racks are difficult to position accurately because they use ordinary motors as the drive source.

[0005] Furthermore, filter presses used for solid-liquid separation typically process solutions containing fluoride ions or other highly corrosive substances. Timely cleaning of the filter press itself, especially the filter plates and filter cloths, is crucial for improving equipment reliability and extending its service life. However, most filter presses on the market rely on manual cleaning; even when cleaning programs are designed, they are only used after the filtration and sludge unloading processes. Insufficient attention to cleaning leads to inadequate equipment reliability, clogged feed lines, and severe wear on filter plates and cloths. In the long run, the quality of the filter cake is also a concern. Summary of the Invention

[0006] In order to improve the problems of low automation and low automation cleaning level of existing solid-liquid separation equipment, this application provides a fully automatic multi-cleaning control method and system for plate and frame filter press.

[0007] Firstly, this application provides a fully automatic multi-cleaning control method for a plate and frame filter press, which adopts the following technical solution: A fully automated multi-cleaning control method for a plate and frame filter press includes the following steps performed in sequence: S1. Filtration process: Fluorine- or sulfur-containing slurry is fed into the filter press through the feed pipeline, and the filter plates are pressed together to separate solids and liquids. S2. First cleaning: After the filter press process is completed, the feed pipeline is purged for 0 to 5 minutes; S3. Sludge unloading process: The filter cake is detached by moving the filter plate by the pull plate trolley, and the sludge unloading cycle is completed; S4. Double cleaning: After the sludge unloading process is completed, use high-pressure water to rinse the feed pipeline and filter plate and filter cloth for no less than 30 seconds. S5. Triple cleaning: After the double cleaning, process water is used to perform deep circulation cleaning on each filter plate and filter cloth. This includes moving the filter plate to the cleaning position by a plate pulling trolley, rinsing the filter plate and filter cloth alternately from top to bottom and from bottom to top after the cleaning rack is precisely positioned, and controlling the opening and closing of the rinsing water path by a three-way valve.

[0008] Furthermore, the first cleaning includes: S21. Open the filtrate discharge valve and purge shut-off valve to form a compressed air flow channel; S22. Use compressed air of 0.4 to 0.6 MPa to purge the feed line. The purging time is adjustable from 0 to 5 minutes. The first cleaning is performed immediately after the filter plates of the filter press are pressed together, in order to reduce the residue of corrosive filtrate in the feed pipeline.

[0009] Furthermore, the double cleaning includes: S41. Open the feed pump drain valve and feed pump flushing valve to form a high-pressure water washing channel; S42. Start the flushing water pump, maintain the water pressure at no less than 1.5MPa and continue flushing for no less than 30 seconds; The secondary cleaning is performed after the sludge unloading cycle is completed, focusing on removing easily detachable filter residue from the inner wall of the feed pipeline and the surface of the filter plate.

[0010] Furthermore, the triple cleaning includes the following steps: S51. Cleaning space reservation: Control the filter press moving plate to close to a pressure of over 12MPa before opening to ensure operating space for the cleaning rack; S52. Precise positioning: The cleaning rack and pull-plate trolley are moved to the cleaning position by a proximity switch; S53. Two-way circulation cleaning: The cleaning rack lifting motor drives the nozzles to rinse the filter plates and filter cloth from top to bottom and then from bottom to top. The rinsing water path is switched and controlled by a three-way valve. S54. Cleaning termination condition: The cycle will automatically terminate when the cleaning rack detects the head plate signal or when all filter plates have been cleaned.

[0011] Furthermore, in step S52, a jog switch and a normally closed contact of a cleaning position proximity switch are connected in parallel in the drive motor control circuit of the pull-plate trolley and the cleaning rack; when the jog switch is closed and the equipment reaches the cleaning position, causing the proximity switch of the cleaning position to open, the drive motor is immediately stopped under control.

[0012] Furthermore, in step S53, when the nozzle starts to move from top to bottom, the three-way valve switches from the self-circulation position to the flushing water supply position, thereby opening the flushing water path; When the nozzle moves from bottom to top to the set position, the three-way valve switches from the flushing water supply position to the self-circulation position, thus closing the flushing water path.

[0013] Furthermore, the control logic for the sludge unloading cycle in step S3 includes: The trolley moves back and forth between the moving plate and the head plate. When the pulling force is greater than 50 bar and lasts for 3 seconds, it switches directions. All filter plates are moved one by one from the moving plate side to the head plate side, and the filter cake falls off automatically without any manual intervention.

[0014] Secondly, this application provides a fully automatic multi-cleaning control system for a plate and frame filter press, used to execute the aforementioned fully automatic multi-cleaning control method for a plate and frame filter press, including: Sensor components: including proximity switches, pressure gauges, solenoid valves, and contactor switches, used to detect filter plate position, pressure status, and equipment operation signals; Actuators include a filter plate moving device, a cleaning frame, a moving plate, an oil tank, nozzles, and a flushing water pump, used to perform filter pressing, sludge unloading, and cleaning actions; Distributed Control System (DCS): It unifies and schedules the three major processes of filter pressing, sludge unloading, and cleaning, integrating them into a continuous automated work cycle, and dynamically controls the actuators based on sensor feedback.

[0015] Furthermore, it also includes a precise positioning device, which includes a jog control switch and a cleaning position proximity switch installed in the control circuit of the pull-plate trolley drive motor and the control circuit of the cleaning rack drive motor. When the cleaning position proximity switch detects that the filter plate or cleaning rack has reached the cleaning position, the cleaning position proximity switch is disconnected to stop the corresponding drive motor.

[0016] Furthermore, the distributed control system (DCS) is configured as follows: During the pressure filtration and primary cleaning process, the distributed control system (DCS) monitors the pressure filtration progress and, after the pressure filtration is completed, stops the feed pump, closes the feed valve, and then opens the purge valve to purge for no less than 60 seconds. In the sludge unloading cycle and secondary cleaning process, the distributed control system (DCS) monitors the pressure sensor on the trolley grabbing mechanism. When the pressure is detected to be greater than 50 bar for 3 seconds, it is determined that the filter plate has been grabbed in place. In the triple cleaning process, the distributed control system (DCS) controls the three-way valve to switch between the self-circulation position and the flushing position.

[0017] In summary, this application includes at least one of the following beneficial technical effects: 1. Full-process automation: It realizes a complete "one-click" automated operation from filter pressing and primary cleaning, sludge unloading and secondary cleaning to tertiary cleaning, which greatly reduces manual operation and improves production efficiency; 2. Multiple cleaning processes improve reliability and service life: Through the design of a first cleaning after filtration, a second cleaning after sludge unloading and circulation, and a third cleaning, each component of the filter press feed pipeline, filter plate and filter cloth, and every piece of equipment that comes into contact with fluorine- and sulfur-containing filtrate and filter cake undergoes two rounds of cleaning. This ensures the cleanliness of the filter press body and filter plates and filter cloth to the greatest extent, greatly improving equipment reliability and extending service life. 3. Precise and reliable control: Condition judgment is based on multi-sensor feedback (pressure sensor, position proximity switch, timer), which ensures the accuracy of each step and the reliability of equipment operation; 4. High adaptability: Key parameters (such as holding pressure, purging time, judgment pressure threshold and delay) can be flexibly set according to process requirements to adapt to different materials and working conditions; 5. High safety: Standardized and consistent automated operation avoids damage to equipment caused by human error, freeing operators from heavy and potentially dangerous on-site operations (such as high pressure and chemical contact), and improving the level of safe production. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 The distribution of proximity switch locations related to the filter press in this application embodiment is set; Figure 2 This is a schematic diagram of the logic control of the filter press and primary cleaning process control module in an embodiment of this application; Figure 3 This is a schematic diagram of the logic control of the sludge unloading and secondary cleaning process control module in an embodiment of this application; Figure 4This is a schematic diagram of the logic control of the triple cleaning program control module in an embodiment of this application.

[0020] Figure label: 1. The plate-pulling trolley is at the tail plate; 2. The cleaning rack is at the head plate; 3. The plate-pulling trolley is in its original position; 4. The cleaning rack is in its original position; 5. The cleaning rack is in the cleaning position; 6. The filter plate is in the cleaning position; 7. The cleaning rack is at the bottom; 8. The cleaning rack is at the top. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0022] Reference Figure 1 This application discloses a fully automatic multi-cleaning control method for a plate and frame filter press, which includes the following steps performed in sequence: S1. Filtration Process: Fluorine- or sulfur-containing slurry is fed into the filter press through the feed pipeline, and the filter plates are pressed together for solid-liquid separation. Specifically, during the filtration process, fluorine- or sulfur-containing slurry containing impurities such as sulfides and nitrogen oxides is fed into the filter press through the feed pipeline, and then the filter plates are hydraulically pressed to 30 MPa, causing the impurities to form a filter cake on the filter plates. If fluorine- or sulfur-containing wastewater residue is not cleaned in time, it can easily adhere to the feed pipeline and filter cloth, clogging the pipeline, corroding the filter cloth and filter plates, and further affecting the quality of the filter cake.

[0023] S2. First cleaning: After the filter press process is completed, the feed pipeline is purged for 0 to 5 minutes.

[0024] S3. Sludge unloading process: The filter cake is detached by moving the filter plate by the pull plate trolley, and the sludge unloading cycle is completed.

[0025] S4. Double cleaning: After the sludge unloading process is completed, use high-pressure water to rinse the feed pipeline and filter plates and filter cloth for no less than 30 seconds.

[0026] S5. Triple Cleaning: After the second cleaning, process water is used to perform deep circulation cleaning on each filter plate and filter cloth. This includes moving the filter plate to the cleaning position by a plate pulling trolley, rinsing the filter plate and filter cloth alternately from top to bottom and from bottom to top after the cleaning rack is precisely positioned, and controlling the flow of the rinsing water through a three-way valve.

[0027] Specifically, refer to Figure 1 and Figure 2During the filtration process, the filter press is first compressed to 30 MPa by closing the moving plates, creating a vacuum siphon environment. Then, the forward and reverse feed valves of the filter press are opened, the feed pump inlet electric valve is opened, and the feed pump is started to begin filtration. During filtration, the feed pressure gradually increases as the filtrate is squeezed. When the feed pressure exceeds the set value, a qualified filter cake is considered to have been formed, and the pressing process ends. The feed pump is then stopped, and the feed pump inlet electric valve and the forward and reverse feed valves of the filter press are closed.

[0028] Specifically, the first stage of cleaning is air washing, which includes: S21. After the filter plates of the filter press are pressed, open the filtrate discharge valve and the purge shut-off valve to form a compressed air flow channel; S22. Use compressed air of 0.4 to 0.6 MPa to purge the feed line. The purging time is adjustable from 0 to 5 minutes, with the default being 60 seconds. The first cleaning step is performed immediately after the filter plates of the filter press are pressed to reduce the residue of corrosive filtrate in the feed line. This also reduces the negative impacts of residual fluoride- and sulfur-containing filtrate on the filter press's feed line components, such as clogging and corrosion, thus improving the filter press's reliability. Furthermore, 0.4–0.6 MPa compressed air is a common working fluid in factories, requiring no additional equipment and having low acquisition costs, making this cleaning process economical.

[0029] Specifically, refer to Figure 1 and Figure 3 The second cleaning process involves water washing, including: S41. After the filter plates of the filter press are unloaded of mud, open the feed pump drain valve and the feed pump flushing valve to form a high-pressure water washing channel; S42. Start the flushing water pump, maintain the water pressure at no less than 1.5MPa and continue flushing for no less than 30 seconds; The second cleaning process is performed after the sludge unloading cycle ends, focusing on removing easily detachable filter cake from the inner wall of the feed pipeline and the surface of the filter plates. Only after the filter press has completed the sludge unloading cycle and the moving plates have opened to create sufficient space can high-pressure flushing water exceeding 0.4–0.6 MPa of compressed air be used for a deeper cleaning of the feed pipeline. For the feed pipeline, the second cleaning is a more thorough cleaning of the first cleaning under more favorable conditions; however, for the filter plates that have just been pressed into filter cake, the second cleaning is a preliminary "edge-wiping" cleaning with high-pressure flushing water, only able to handle small, easily detachable filter cake particles. A large amount of sludge still adheres to the filter plates and filter cloth, clogging the pores and causing severe corrosion. Therefore, a third cleaning process targeting the filter plates and filter cloth is also necessary.

[0030] Reference Figure 1 and Figure 4The triple cleaning process involves circulating water washing to remove filter cake residue that is difficult to detach from the filter cloth and filter plates after sludge unloading. Specifically, it involves starting the filter cloth cleaning water pump and using process water at approximately 2 MPa to deeply circulate and clean each filter plate and filter cloth. For the filter plates and filter cloth, this is a continuation and deepening of the double cleaning process.

[0031] Furthermore, in step S52, a jog switch and a normally closed contact of a cleaning position proximity switch are connected in parallel in the drive motor control circuit of the pull-plate trolley and the cleaning rack; when the jog switch is closed and the equipment reaches the cleaning position, causing the proximity switch of the cleaning position to open, the drive motor is immediately stopped under control.

[0032] In step S53, when the nozzle starts to move from top to bottom, the three-way valve switches from the self-circulation position to the flushing water supply position, so that the flushing water path is opened. When the nozzle moves from bottom to top to the set position, the three-way valve switches from the flushing water supply position to the self-circulation position, thus closing the flushing water path.

[0033] Furthermore, the control logic for the sludge unloading cycle in step S3 includes: The plate-pulling trolley reciprocates between the moving plate and the head plate. When the pulling pressure is greater than 50 bar and lasts for 3 seconds, it switches directions. All filter plates are moved from the moving plate side to the head plate side one by one, and the filter cake falls off automatically. No manual intervention is required throughout the process.

[0034] Specifically, after filtration is complete, each filter plate needs to be pulled from the head plate to the moving plate by a plate-pulling trolley (plate-shifting device), causing the filter cake to fall off and be unloaded. This process is called sludge unloading. Since a filter press has at least 50 filter plates, the need to pull these plates one by one is often achieved through a cyclic control logic design. Therefore, the process of unloading sludge from all filter press plates is also called filter press sludge unloading cycle. Specifically, the filtrate discharge valve and purge shut-off valve are closed, the pressure holding is disengaged, the flap is opened, and the filter press is turned on. The plate-pulling trolley repeatedly switches between moving towards the moving plate and moving towards the head plate until all filter plates have switched from the side closer to the moving plate to the side closer to the head plate. When the pulling pressure is greater than 50 bar and the delay is more than 3 seconds, it is considered that the plate-pulling trolley has moved the filter plate into place, and the direction is switched.

[0035] In practice, the following steps can be followed: P1: After the sludge unloading process is completed, a cleaning space is reserved. The filter press moving plate closes; when the filter press closing pressure reaches 12MPa or higher; the filter press is then opened until the filter press operating side moving plate and non-operating side moving plate are both in their original positions.

[0036] P2: The cleaning rack returns to its original position. The cleaning rack moves towards the movable plate until it returns to its original position.

[0037] P3: The pull-plate trolley returns to its original position. The pull-plate trolley moves towards the moving plate until it returns to its original position.

[0038] P4: Prepare filter cloth rinsing water. Start the filter cloth cleaning water pump and turn the filter cloth cleaning water pump outlet tee to the closed position (self-circulation position).

[0039] P5: Washing rack to washing position. The washing rack moves toward the headboard until it is in the washing position.

[0040] P6: The plate-pulling trolley grips the filter plate. The plate-pulling trolley moves towards the head plate until the gripping pressure is greater than 50 bar. That is, the plate-pulling trolley grips the filter plate.

[0041] P7: The plate-pulling trolley moves the filter plate to the cleaning position. The pull-grabbing trolley moves towards the moving plate until the filter plate is in the cleaning position, that is, the plate-pulling trolley (plate-moving device) moves the filter plate to the cleaning position in the middle of the cleaning frame.

[0042] P8: Cleaning filter plates and filter cloth - from top to bottom. The cleaning rack lifting motor moves downwards until the cleaning rack is at the bottom. Once the signal is received, indicating that the cleaning rack and filter plates are in place (at the same time, they are in the cleaning position), rinse from top to bottom.

[0043] P9: Cleaning filter plates and filter cloth - from bottom to top. The cleaning rack lifting motor moves upward until the cleaning rack is at the top. Once the signal comes, indicating that the cleaning rack and filter plates are in place (at the same time, they are in the cleaning position), rinse from bottom to top.

[0044] P10: Place the filter plate, which is about to be cleaned, on the side of the moving plate. Move the gripping trolley towards the moving plate until the gripping pressure is greater than 50 bar.

[0045] P11: In step P8, when the nozzle closing proximity switch changes from 1 to 0, the filter cloth rinsing water pump outlet tee changes from the closed position (self-circulation position) to the open position (rinsing water level), that is, the rinsing water path is opened and the filter plate is rinsed; In step P9, when the nozzle closing proximity switch changes from 0 to 1, the filter cloth rinsing water pump outlet tee changes from the open position (rinsing water level) to the closed position (self-circulation position), that is, the rinsing water path is closed and rinsing stops.

[0046] P12: Cleaning cycle, which is terminated when the cleaning rack signal on the head plate or tail plate disappears, or when the cleaning count indicates that all filter plates have been cleaned.

[0047] This application also discloses a fully automatic multi-cleaning control system for a plate and frame filter press, used to execute the above-mentioned fully automatic multi-cleaning control method for a plate and frame filter press, employing the following technical solution: A fully automatic multi-cleaning control system for a plate and frame filter press includes: Sensor components: including proximity switches, pressure gauges, solenoid valves, and contactor switches, used to detect filter plate position, pressure status, and equipment operation signals; Actuators include a filter plate moving device, a cleaning frame, a moving plate, an oil tank, nozzles, and a flushing water pump, used to perform filter pressing, sludge unloading, and cleaning actions; Distributed Control System (DCS): It unifies and schedules the three major processes of filter pressing, sludge unloading, and cleaning, integrates them into a continuous automated work cycle, and dynamically controls the actuators based on sensor feedback. A precise positioning device, comprising a jog control switch and a cleaning position proximity switch installed in the control circuit of the pull-plate trolley drive motor and the control circuit of the cleaning rack drive motor; When the cleaning position proximity switch detects that the filter plate or cleaning rack has reached the cleaning position, the cleaning position proximity switch is disconnected to stop the corresponding drive motor.

[0048] The distributed control system (DCS) is configured as follows: During the pressure filtration and primary cleaning process, the distributed control system (DCS) monitors the pressure filtration progress and, after the pressure filtration is completed, stops the feed pump, closes the feed valve, and then opens the purge valve to purge for no less than 60 seconds. In the sludge unloading cycle and secondary cleaning process, the distributed control system (DCS) monitors the pressure sensor on the trolley grabbing mechanism. When the pressure is detected to be greater than 50 bar for 3 seconds, it is determined that the filter plate has been grabbed in place. In the triple cleaning process, the distributed control system (DCS) controls the three-way valve to switch between the self-circulation position and the flushing position.

[0049] Specifically, refer to Figure 2 The following is an example of pressure filtration and primary cleaning process control: The DCS first outputs a signal to control the flap cylinder to close the flap. Then, it controls the hydraulic station motor to start, pressing the filter press to 30MPa and entering the pressure holding state. Subsequently, the DCS sequentially opens the forward and reverse feed valves, the feed pump inlet electric valve, and finally starts the feed pump to begin filtration. The DCS continuously monitors the pressure sensor on the feed pipeline. When the pressure remains above the set value (e.g., 0.7MPa), it determines that filtration is complete. The DCS then proceeds in sequence: stops the feed pump → closes the feed valve → opens the purge valve for a 60-second (adjustable) purge. After purge, the purge valve is closed, the hydraulic station is depressurized, and the filter press and flap are opened. Finally, the flushing water pump and corresponding valves are turned on to flush the feed pump for a preset time, after which the sludge unloading procedure begins.

[0050] Reference Figure 3 The implementation examples of sludge unloading circulation and secondary cleaning process control are as follows: The DCS controls the motor of the filter plate pulling trolley to run forward, moving the trolley towards the moving plate. When the pressure sensor on the trolley's gripping mechanism detects a pressure greater than 50 bar for 3 seconds, the DCS determines that the filter plate has been gripped and controls the trolley to run in reverse, pulling the filter plate towards the head plate. This process is repeated until the filter plate is completely pulled apart and the filter cake falls off.

[0051] Reference Figure 4 The triple cleaning process control implementation example is as follows: After sludge discharge, the DCS controls the filter press to close slightly and then open, creating space for cleaning. Then, the cleaning frame moves to its initial position, and the pull-plate trolley returns to its initial gripping position. The cleaning water pump is started, and the three-way valve enters self-circulation mode.

[0052] After entering the circulation phase, the cleaning rack moves to the waiting position (cleaning position), and the pull-plate trolley grabs the first filter plate and drags it to the center of the cleaning rack. The cleaning rack descends, and during the descent, the nozzle proximity switch changes state (1→0), triggering the DCS to switch the three-way valve from self-circulation to the flushing position, and high-pressure water begins to flush the filter cloth from top to bottom. After reaching the bottom, the cleaning rack rises, and during the rise, the proximity switch state changes again (0→1), and the DCS controls the three-way valve to switch back to self-circulation, stopping the flushing. The pull-plate trolley then places the cleaned filter plate back to its original position and moves on to grab the next filter plate. The circulation continues until all filter plates have been cleaned. Finally, all equipment returns to its original position, and the water pump stops.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fully automatic multi-cleaning control method for a plate and frame filter press, characterized in that, The steps are executed in the following order: S1. Filtration process: Fluorine- or sulfur-containing slurry is fed into the filter press through the feed pipeline, and the filter plates are pressed together to separate solids and liquids. S2. First cleaning: After the filter press process is completed, the feed pipeline is purged for 0 to 5 minutes; S3. Sludge unloading process: The filter cake is detached by moving the filter plate by the pull plate trolley, and the sludge unloading cycle is completed; S4. Double cleaning: After the sludge unloading process is completed, use high-pressure water to rinse the feed pipeline and filter plate and filter cloth for no less than 30 seconds. S5. Triple cleaning: After the double cleaning, process water is used to perform deep circulation cleaning on each filter plate and filter cloth. This includes moving the filter plate to the cleaning position by a plate pulling trolley, rinsing the filter plate and filter cloth alternately from top to bottom and from bottom to top after the cleaning rack is precisely positioned, and controlling the opening and closing of the rinsing water path by a three-way valve.

2. The fully automatic multi-cleaning control method for a plate and frame filter press according to claim 1, characterized in that, The first cleaning includes: S21. Open the filtrate discharge valve and purge shut-off valve to form a compressed air flow channel; S22. Use compressed air of 0.4 to 0.6 MPa to purge the feed line. The purging time is adjustable from 0 to 5 minutes. The first cleaning is performed immediately after the filter plates of the filter press are pressed together, in order to reduce the residue of corrosive filtrate in the feed pipeline.

3. The fully automatic multi-cleaning control method for a plate and frame filter press according to claim 1, characterized in that, The double cleaning includes: S41. Open the feed pump drain valve and feed pump flushing valve to form a high-pressure water washing channel; S42. Start the flushing water pump, maintain the water pressure at no less than 1.5MPa and continue flushing for no less than 30 seconds; The secondary cleaning is performed after the sludge unloading cycle is completed, focusing on removing easily detachable filter residue from the inner wall of the feed pipeline and the surface of the filter plate.

4. The fully automatic multi-cleaning control method for a plate and frame filter press according to claim 1, characterized in that, The triple cleaning process includes the following steps: S51. Cleaning space reservation: Control the filter press moving plate to close to a pressure of over 12MPa before opening to ensure operating space for the cleaning rack; S52. Precise positioning: The cleaning rack and pull-plate trolley are moved to the cleaning position by a proximity switch; S53. Two-way circulation cleaning: The cleaning rack lifting motor drives the nozzles to rinse the filter plates and filter cloth from top to bottom and then from bottom to top. The rinsing water path is switched and controlled by a three-way valve. S54. Cleaning termination condition: The cycle will automatically terminate when the cleaning rack detects the head plate signal or when all filter plates have been cleaned.

5. The fully automatic multi-cleaning control method for a plate and frame filter press according to claim 4, characterized in that, In step S52, a jog switch and a normally closed contact of a cleaning position proximity switch are connected in parallel in the drive motor control circuit of the pull-plate trolley and the cleaning rack; when the jog switch is closed and the equipment reaches the cleaning position, causing the proximity switch of the cleaning position to open, the drive motor is immediately stopped under control.

6. The fully automatic multi-cleaning control method for a plate and frame filter press according to claim 4, characterized in that, In step S53, when the nozzle starts to move from top to bottom, the three-way valve switches from the self-circulation position to the flushing water supply position, so that the flushing water path is opened. When the nozzle moves from bottom to top to the set position, the three-way valve switches from the flushing water supply position to the self-circulation position, thus closing the flushing water path.

7. The fully automatic multi-cleaning control method for a plate and frame filter press according to claim 1, characterized in that, The control logic for the sludge unloading cycle in step S3 includes: The trolley moves back and forth between the moving plate and the head plate. When the pulling force is greater than 50 bar and lasts for 3 seconds, it switches directions. All filter plates are moved one by one from the moving plate side to the head plate side, and the filter cake falls off automatically without any manual intervention.

8. A fully automatic multi-cleaning control system for a plate and frame filter press, used to execute the fully automatic multi-cleaning control method for a plate and frame filter press as described in any one of claims 1-7, characterized in that, include: Sensor components: including proximity switches, pressure gauges, solenoid valves, and contactor switches, used to detect filter plate position, pressure status, and equipment operation signals; Actuators include a filter plate moving device, a cleaning frame, a moving plate, an oil tank, nozzles, and a flushing water pump, used to perform filter pressing, sludge unloading, and cleaning actions; Distributed Control System (DCS): It unifies and schedules the three major processes of filter pressing, sludge unloading, and cleaning, integrating them into a continuous automated work cycle, and dynamically controls the actuators based on sensor feedback.

9. The fully automatic multi-cleaning control system for a plate and frame filter press according to claim 8, characterized in that, It also includes a precise positioning device, which includes a jog control switch and a cleaning position proximity switch installed in the control circuit of the pull-plate trolley drive motor and the control circuit of the cleaning rack drive motor. When the cleaning position proximity switch detects that the filter plate or cleaning rack has reached the cleaning position, the cleaning position proximity switch is disconnected to stop the corresponding drive motor.

10. The fully automatic multi-cleaning control system for a plate and frame filter press according to claim 8, characterized in that, The distributed control system (DCS) is configured as follows: During the pressure filtration and primary cleaning process, the distributed control system (DCS) monitors the pressure filtration progress and, after the pressure filtration is completed, stops the feed pump, closes the feed valve, and then opens the purge valve to purge for no less than 60 seconds. In the sludge unloading cycle and secondary cleaning process, the distributed control system (DCS) monitors the pressure sensor on the trolley grabbing mechanism. When the pressure is detected to be greater than 50 bar for 3 seconds, it is determined that the filter plate has been grabbed in place. In the triple cleaning process, the distributed control system (DCS) controls the three-way valve to switch between the self-circulation position and the flushing position.

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