Membrane filtration automation control device and implementation method thereof

Abstract

The application belongs to the technical field of membrane filtration unit control, and provides a kind of membrane filtration automatic control equipment and its implementation method.The application includes programmable logic controller in communication with host computer, feed pump, circulating pump, dosing pump, dosing pump, proportional valve and pneumatic diaphragm valve controlled by programmable logic controller, wherein, the method includes: the step of selecting control mode based on host computer and sending to programmable logic controller;The step of programmable logic controller generating control instructions corresponding to each control component according to control mode after executing logic operation;The step of control component running according to control instruction.The application can be widely applied to electrical automation control of membrane filtration unit, realize seven working modes: production mode, pickling mode, alkaline cleaning mode, flushing mode, top washing mode, mixed cleaning mode and emptying mode, greatly enrich the operability of membrane filtration unit, expand the application of membrane filtration unit.

Description

Technical Field

[0001] This invention belongs to the field of membrane filtration unit control technology, specifically, it relates to an automated control device for membrane filtration and its implementation method. Background Technology

[0002] Membrane filtration units are devices used for filtration. The core of this equipment is the filter membrane, and the automated control equipment for membrane filtration is a crucial component. It controls the membrane filtration unit and is widely used in the electrical automation control of membrane filtration units; it is the soul of the unit. In existing technologies, the automated control equipment for membrane filtration is relatively simple in structure, with a single control method, low control precision, and the need for manual intervention in switching between processes. This results in long downtimes for the membrane filtration unit, affecting production operations. Furthermore, existing technologies for cleaning membrane filtration units all employ single cleaning operations, leading to low cleaning efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide an automated control device for membrane filtration to solve the technical problems existing in the prior art.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An automated control device for membrane filtration includes a programmable logic controller (PLC) that communicates with a host computer, and a feed pump, a circulation pump, a dosing pump, a proportional valve, and a pneumatic diaphragm valve controlled by the PLC; the pneumatic diaphragm valve includes a first pneumatic diaphragm valve, a second pneumatic diaphragm valve, a third pneumatic diaphragm valve, a fourth pneumatic diaphragm valve, a fifth pneumatic diaphragm valve, a sixth pneumatic diaphragm valve, a seventh pneumatic diaphragm valve, an eighth pneumatic diaphragm valve, a ninth pneumatic diaphragm valve, a tenth pneumatic diaphragm valve, an eleventh pneumatic diaphragm valve, and a twelfth pneumatic diaphragm valve. The second pneumatic diaphragm valve is installed on the pipeline connecting the circulation tank and the membrane system. The twelfth pneumatic diaphragm valve is installed on the cleaning liquid delivery pipeline of the circulation tank. The first and tenth pneumatic diaphragm valves are installed on the outlet pipeline of the circulation tank. The dosing pump is installed on the dosing device. The fifth pneumatic diaphragm valve is installed on the dosing delivery pipeline. The feed pump and the circulation pump are sequentially installed at the outlet end of the fifth pneumatic diaphragm valve. A pipeline connects the feed pump and the circulation pump, and the fourth pneumatic diaphragm valve is installed on it. The proportional valve, the seventh pneumatic diaphragm valve, the eighth pneumatic diaphragm valve, the ninth pneumatic diaphragm valve, and the eleventh pneumatic diaphragm valve are used to regulate the membrane system. The third and sixth pneumatic diaphragm valves are installed on the feed pipeline of the filtrate tank.

[0005] To achieve the above objectives, the present invention also provides a method for implementing an automated control device for membrane filtration, comprising the following steps: Step S1: Selecting the control mode based on the host computer and sending it to the programmable logic controller; Step S2: The programmable logic controller (PLC) performs logical operations according to the control mode and then generates control instructions for each control component. Step S3: The steps by which the control unit operates according to the control instructions; In step S1, the control modes include production mode, pickling mode, alkaline washing mode, rinsing mode, top washing mode, mixed cleaning mode and evacuation mode. The control components in step S2 include a feed pump, a circulation pump, a dosing pump, a pneumatic diaphragm valve, a proportional valve, and a dosing pump.

[0006] In one implementation, when the control mode is selected as production mode in step S1, the control command in step S2 includes: opening the first pneumatic diaphragm valve, the second pneumatic diaphragm valve, the third pneumatic diaphragm valve, the fourth pneumatic diaphragm valve, and the proportional valve, and then starting the feed pump and the circulation pump in sequence. The opening degree of the proportional valve is controlled by PID, that is, the difference between the current concentrate flow rate and the set flow rate is used to control the opening degree of the proportional valve; the speed of the feed pump is controlled by PID, that is, the difference between the current filtrate flow rate and the set flow rate is used to control the speed of the feed pump.

[0007] In one implementation, when the control mode is selected as cleaning mode in step S1, the control command in step S2 includes: opening the corresponding valves and water pumps, and automatically stopping the machine after the process requirements are met, as follows: The cleaning mode activates the following valves and pumps: the first, second, fourth, sixth, and twelfth pneumatic diaphragm valves, the proportional valve, the water supply pump, the feed pump, the circulation pump, and the dosing pump. The twelfth pneumatic diaphragm valve's operation is controlled by the circulating tank level; it opens when the current level is below the low level and closes when it is above the high level but below the low level. The dosing pump's operation is controlled by the cleaning solution's pH value. In acid washing mode, the pump starts adding acid when the current pH value is greater than the set value and shuts off when the current pH value is less than or equal to the set value. In alkaline washing mode, the pump starts adding alkali when the current pH value is less than the set value and shuts off when the current pH value is greater than or equal to the set value.

[0008] In one implementation, when the control mode is selected as flushing mode in step S1, the control command in step S2 includes: opening the corresponding valves and water pumps, and automatically stopping the machine after the process requirements are met, as follows: Flushing mode opens valves and water pumps: opens the first pneumatic diaphragm valve, the seventh pneumatic diaphragm valve, the eighth pneumatic diaphragm valve, the ninth pneumatic diaphragm valve, the proportional valve, the feed pump, and the circulation pump.

[0009] In one implementation, when the control mode is selected as top-wash mode in step S1, the control command in step S2 includes: opening the corresponding valves and water pumps, and automatically stopping the machine after the process requirements are met, as follows: Top washing mode opens valves and water pumps: opens the first pneumatic diaphragm valve, the second pneumatic diaphragm valve, the fourth pneumatic diaphragm valve, the sixth pneumatic diaphragm valve, the proportional valve, the feed pump, and the circulation pump.

[0010] In one implementation, when the control mode is selected as the venting mode in step S1, the control command in step S2 includes: opening the corresponding valves and water pumps, and automatically stopping the machine after the process requirements are met, as follows: In the venting mode, the following valves are opened: the first, second, fourth, sixth, seventh, eighth, ninth, tenth, and eleventh pneumatic diaphragm valves and the proportional valve.

[0011] In one implementation, when the control mode is selected as a mixed cleaning mode in step S1, it includes any combination of acid washing mode, alkaline washing mode, rinsing mode and draining mode in any order.

[0012] In one implementation, the process requirements include the number of runs and the duration.

[0013] In one implementation, an alarm step is also included: (I) If any control component in the membrane filtration automated control equipment malfunctions, an alarm sound and an alarm flash will be emitted; (II) If any component in the membrane filtration unit malfunctions, an alarm sound and an alarm flash will be emitted; (III) If the membrane filter unit stops suddenly, an alarm sound and an alarm flash will be emitted.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention includes a programmable logic controller that communicates with a host computer, and a feed pump, a circulation pump, a dosing pump, a pneumatic diaphragm valve and a proportional valve controlled by the programmable logic controller. The membrane filtration automation control equipment can be controlled locally or remotely, and can realize seven working modes of the membrane filtration unit: production mode, acid washing mode, alkali washing mode, rinsing mode, top washing mode, mixed cleaning mode and venting mode, which greatly enriches the operating modes of the membrane filtration unit, and each process does not require manual intervention to switch, thus expanding the application of the membrane filtration unit. This invention can be widely used in the electrical automation control of the membrane filtration unit and is the soul of the membrane filtration unit.

[0015] (2) The present invention introduces a mixed cleaning mode, including any combination of acid washing mode, alkaline washing mode, rinsing mode and evacuation mode in any order, up to 16 combinations. Each mode can be set with corresponding number of working times and duration. Based on the setting of the mixed cleaning mode, the cleaning operation of the membrane filter unit is more flexible, and the cleaning efficiency and membrane flux recovery rate are higher. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the principle of the present invention.

[0017] The corresponding names of the attached figures are as follows: 1-Feed pump, 2-Circulation pump, 3-Control cabinet, 4-Dosing pump, 5-Raw material conveying pipeline, 6-Cooling water process pipeline, 7-Circulation tank, 8-Compressed air pipeline, 9-Cleaning fluid conveying pipeline, 10-Hot water conveying pipeline, 11-Membrane system, 12-Dosing device, 13-Dosing conveying pipeline, 14-Cooling water return pipeline, 15-Filtrate tank, 16-Proportional valve; F1 - First pneumatic diaphragm valve, F2 - Second pneumatic diaphragm valve, F3 - Third pneumatic diaphragm valve, F4 - Fourth pneumatic diaphragm valve, F5 - Fifth pneumatic diaphragm valve, F6 - Sixth pneumatic diaphragm valve, F7 - Seventh pneumatic diaphragm valve, F8 - Eighth pneumatic diaphragm valve, F9 - Ninth pneumatic diaphragm valve, F10 - Tenth pneumatic diaphragm valve, F11 - Eleventh pneumatic diaphragm valve, F12 - Twelfth pneumatic diaphragm valve. Detailed Implementation

[0018] To enable those skilled in the art to have a clearer understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described below are merely for illustrative purposes and to facilitate understanding. The technical solutions provided by the present invention are not limited to those provided in the following embodiments, nor should they limit the scope of protection of the present invention.

[0019] Example 1 like Figure 1As shown, this embodiment provides an automated control device for membrane filtration, including a programmable logic controller (PLC) that communicates with a host computer, a feed pump 1, a circulation pump 2, a dosing pump 4, a proportional valve 16, and pneumatic diaphragm valves controlled by the PLC, and control devices for the pneumatic diaphragm valves. The pneumatic diaphragm valves include a first pneumatic diaphragm valve F1, a second pneumatic diaphragm valve F2, a third pneumatic diaphragm valve F3, a fourth pneumatic diaphragm valve F4, a fifth pneumatic diaphragm valve F5, a sixth pneumatic diaphragm valve F6, a seventh pneumatic diaphragm valve F7, an eighth pneumatic diaphragm valve F8, a ninth pneumatic diaphragm valve F9, a tenth pneumatic diaphragm valve F10, an eleventh pneumatic diaphragm valve F11, and a twelfth pneumatic diaphragm valve F12. It should be noted that many other valves are also used in membrane filtration units; this embodiment only lists the valves used for control in this application, and other valves not involved in the control are not listed.

[0020] This embodiment uses the aforementioned components to construct a control device for the membrane filtration unit. The programmable logic controller (PLC) can be any existing, mature controller model. The membrane filtration unit includes a circulation tank, a membrane system matched to the circulation tank, and a filtrate tank at the end. The circulation tank is connected to raw material delivery pipes, cleaning solution delivery pipes, and hot water delivery pipes. The membrane system is connected to cooling water inlet pipes and cooling water return pipes. Compressed air pipes are connected to the membrane system at the end and controlled by a control cabinet. Depending on the composition of the membrane filtration unit, it may include multiple circulation tanks. The main innovation of this technology lies in the composition of each component and the design of the corresponding valve positions, thereby laying the equipment foundation for realizing the control of seven operating modes of the membrane filtration unit.

[0021] In this embodiment, the specific locations of each pneumatic diaphragm valve are as follows: the second pneumatic diaphragm valve F2 is located on the pipe connecting the circulation tank 7 and the membrane system 11; the twelfth pneumatic diaphragm valve F12 is located on the cleaning liquid conveying pipe 9 of the circulation tank 7; the first pneumatic diaphragm valve F1 and the tenth pneumatic diaphragm valve F10 are located on the outlet pipe of the circulation tank 7; the dosing pump 4 is located on the dosing device 12; the fifth pneumatic diaphragm valve F5 is located on the dosing conveying pipe 13; the feed pump 1 and the circulation pump 2 are sequentially located at the outlet end of the fifth pneumatic diaphragm valve F5; a pipe connects the feed pump 1 and the circulation pump 2 and a fourth pneumatic diaphragm valve F4 is located on it; the proportional valve 16, the seventh pneumatic diaphragm valve F7, the eighth pneumatic diaphragm valve F8, the ninth pneumatic diaphragm valve F9, and the eleventh pneumatic diaphragm valve F11 are used to regulate the membrane system 11; and the third pneumatic diaphragm valve F3 and the sixth pneumatic diaphragm valve F6 are located on the feed pipe of the filtrate tank 15.

[0022] The membrane filtration automation control equipment can be controlled locally or remotely (4G). Only one control scheme is effective at a time: local effective, remote ineffective, or both are ineffective and the equipment is in a disabled state. Both control schemes can communicate with the host computer. Both local and remote control modes have manual / automatic switching functions, with only one control scheme effective at a time: manual effective, automatic ineffective, or both are ineffective and the equipment is in a disabled state. During manual control, mode control and automatic start-up are disabled; during automatic control, manual control elements are disabled.

[0023] Example 2 This embodiment provides a method for implementing the automated control device for membrane filtration provided in Embodiment 1, including the following steps: Step S1: Select the control mode based on the host computer and send it to the programmable logic controller; the control modes include production mode, acid washing mode, alkaline washing mode, rinsing mode, top washing mode, mixed cleaning mode and evacuation mode. The seven control modes are only valid in automatic control mode, and only one control mode is valid at any given time.

[0024] Step S2: The programmable logic controller performs logical operations according to the control mode and generates control instructions for each control component; wherein, the control components include feed pump 1, circulation pump 3, dosing pump 4, proportional valve 16 and pneumatic diaphragm valve.

[0025] Step S3: The steps by which the control unit operates according to the control instructions.

[0026] Based on the above steps, this embodiment provides a detailed description of each working mode: When the control mode is set to production mode, the equipment is started by selecting production mode on the human-machine interface / host computer. The equipment opens the corresponding valves according to the requirements, and uses PID control to control the water pump speed and the opening of the pneumatic diaphragm valve, so that the measured flow rate always remains consistent with the set flow rate. The PID control is implemented by a programmable logic controller through programming. The PID control mechanism is as follows: when the measured concentrate flow rate is greater than the set flow rate, the proportional valve opening decreases; when the measured concentrate flow rate is less than the set flow rate, the proportional valve opening increases. When the measured filtrate flow rate is greater than the set flow rate, the water pump speed decreases; when the measured filtrate flow rate is less than the set flow rate, the water pump speed increases. The specific control instructions for each control component include: opening the first pneumatic diaphragm valve F1, the second pneumatic diaphragm valve F2, the fourth pneumatic diaphragm valve F4, the sixth pneumatic diaphragm valve F6, the twelfth pneumatic diaphragm valve F12, the proportional valve 16, the water supply pump, the feed pump, and the circulation pump. Among them, the opening of the proportional valve 16 is controlled by the PID controller, that is, the negative feedback control of the difference between the current concentrate flow rate and the set flow rate controls the opening of the proportional valve 16.

[0027] When the control mode is selected as cleaning mode, rinsing mode, top washing mode, or draining mode, the control commands in step S2 include: opening the corresponding valves and water pumps, and automatically stopping the machine after the process requirements are met. The process requirements include the number of runs and the duration, as detailed below: 1. Cleaning mode valve and water pump opening: Open the first pneumatic diaphragm valve F1, the second pneumatic diaphragm valve F2, the fourth pneumatic diaphragm valve F4, the sixth pneumatic diaphragm valve F6, the twelfth pneumatic diaphragm valve F12, the proportional valve 16, the water supply pump, the feed pump, and the circulation pump; among which, the opening and closing of the twelfth pneumatic diaphragm valve F12 is controlled by the liquid level of the circulation tank, that is, when the current liquid level is lower than the low liquid level, the twelfth pneumatic diaphragm valve F12 is open, and when the current liquid level is higher than the high liquid level and lower than the low liquid level, the twelfth pneumatic diaphragm valve F12 is closed.

[0028] The cleaning modes include acid washing and alkaline washing. A dosing pump is used to add cleaning chemicals. Whether or not chemicals are added depends on the pH value of the cleaning solution, which can be measured using an H sensor. If chemical addition is required, the dosing pump, the fifth pneumatic diaphragm valve F5, and the dosing pump are activated. The dosing pump's operation is controlled as follows depending on the cleaning conditions: In acid washing mode, the dosing pump activates to add acid when the current pH value is greater than the set value, and deactivates when the current pH value is less than or equal to the set value. In alkaline washing mode, the dosing pump activates to add alkali when the current pH value is less than the set value, and deactivates when the current pH value is greater than or equal to the set value.

[0029] 2. Flushing mode: Open valves and water pumps: Open the first pneumatic diaphragm valve F1, the seventh pneumatic diaphragm valve F7, the eighth pneumatic diaphragm valve F8, the ninth pneumatic diaphragm valve F9, the proportional valve 16, the feed pump, and the circulation pump.

[0030] 3. Top washing mode: Open valves and water pumps: Open the first pneumatic diaphragm valve F1, the second pneumatic diaphragm valve F2, the fourth pneumatic diaphragm valve F4, the sixth pneumatic diaphragm valve F6, the proportional valve 16, the feed pump and the circulation pump.

[0031] 4. Vacuum mode valve opening: Open the first pneumatic diaphragm valve F1, the second pneumatic diaphragm valve F2, the fourth pneumatic diaphragm valve F4, the sixth pneumatic diaphragm valve F6, the seventh pneumatic diaphragm valve F7, the eighth pneumatic diaphragm valve F8, the ninth pneumatic diaphragm valve F9, the tenth pneumatic diaphragm valve F10, the eleventh pneumatic diaphragm valve F11 and the proportional valve 16.

[0032] When the control mode is selected as the mixed cleaning mode, it includes any combination of acid washing, alkaline washing, rinsing, and draining modes in any order, up to 16 combinations. The number of cycles and duration for each mode can also be set. Errors during the setting process can be cleared and reset. If conditions are not met during mixed cleaning, the system enters a waiting program until the conditions are met before resuming execution. After each mode is completed, the system issues a relevant audible and visual alarm to prompt personnel, and the system will then enter the next mode. It should be noted that the interval between the acid washing and alkaline washing modes is 5-30 minutes, and the draining mode is forcibly executed after each alternation.

[0033] The control sequence for the mixed cleaning mode includes: 1. Opening the corresponding valves and water pumps to execute the first sequence of control modes and meet the process requirements; 2. Generating a prompt and entering the second sequence of control modes, opening the corresponding valves and water pumps, and executing the second sequence of control modes to meet the process requirements; 3. Generating a prompt and entering the third sequence of control modes, opening the corresponding valves and water pumps, and executing the third sequence of control modes to meet the process requirements; 4. Generating a prompt and entering the fourth sequence of control modes, opening the corresponding valves and water pumps, and executing the fourth sequence of control modes to meet the process requirements. The prompts include an alarm sound and an alarm flashing light.

[0034] Examples of mixed cleaning modes: First cycle (number of cycles): Acid washing mode (number of cycles + duration) - Alkaline washing mode (number of cycles + duration) - Rinsing mode (number of cycles + duration) - Draining mode (number of cycles + duration); b. Second cycle (number of times): Alkaline washing mode (number of times + duration) - Acid washing mode (number of times + duration) - Rinsing mode (number of times + duration) - Draining mode (number of times + duration); c. Third cycle (number of times): Acid washing mode (number of times + duration) - Alkali washing mode (number of times + duration) - Drain mode (number of times + duration) - Rinse mode (number of times + duration).

[0035] In the mixed cleaning mode, the number of cycles can be set for each cycle. Once the required number of cycles is reached, the system will enter a shutdown procedure. Each cleaning cycle must include a purging process; otherwise, the setting will be invalid. Testing has shown that the mixed cleaning mode significantly improves membrane flux recovery, with each cycle including a 3-minute purging step.

[0036] In this embodiment, the method for implementing automated control equipment for membrane filtration also includes an alarm mechanism: (I) If any control component in the membrane filtration automated control equipment malfunctions, an alarm sound and an alarm flash will be emitted; (II) If any component in the membrane filtration unit malfunctions, an alarm sound and an alarm flash will be emitted; (III) If the membrane filter unit stops suddenly, an alarm sound and an alarm flash will be emitted.

[0037] Based on the method provided in this embodiment, the start-up / stop mechanism of the membrane filtration automated control equipment can be set as follows: Start-up sequence: valves related to each mode → detection that all valves are fully open → feed pump → reaching set speed → high-pressure pump → reaching set speed → circulation pump → reaching set speed → start-up complete; Shutdown sequence: Circulation pump → Speed ​​zero → High pressure pump → Speed ​​zero → Feed pump → Speed ​​zero → Close relevant valves → Detect all valves are closed → Delay → Time expires → Shutdown ends.

[0038] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An automated control device for membrane filtration, characterized in that, The system includes a programmable logic controller (PLC) that communicates with a host computer, and a feed pump (1), a circulation pump (2), a dosing pump (4), a proportional valve (16), and a pneumatic diaphragm valve controlled by the PLC. The pneumatic diaphragm valve includes a first pneumatic diaphragm valve (F1), a second pneumatic diaphragm valve (F2), a third pneumatic diaphragm valve (F3), a fourth pneumatic diaphragm valve (F4), a fifth pneumatic diaphragm valve (F5), a sixth pneumatic diaphragm valve (F6), a seventh pneumatic diaphragm valve (F7), an eighth pneumatic diaphragm valve (F8), a ninth pneumatic diaphragm valve (F9), a tenth pneumatic diaphragm valve (F10), an eleventh pneumatic diaphragm valve (F11), and a twelfth pneumatic diaphragm valve (F12). The second pneumatic diaphragm valve (F2) is installed on the pipeline connecting the circulating tank (7) and the membrane system (11). The twelfth pneumatic diaphragm valve (F12) is installed on the cleaning fluid delivery pipeline (9) of the circulating tank (7). The first pneumatic diaphragm valve (F1) and the tenth pneumatic diaphragm valve (F10) are installed on the outlet pipeline of the circulating tank (7). The dosing pump (4) is installed on the dosing device (12). The fifth pneumatic diaphragm valve (F5) is installed on the dosing delivery pipeline (13). The feed pump (1) and the circulating pump (F10) are installed on the dosing device (12). 2) The fifth pneumatic diaphragm valve (F5) is sequentially installed at the outlet end of the fifth pneumatic diaphragm valve (F5). A pipeline is connected between the feed pump (1) and the circulation pump (2) and the fourth pneumatic diaphragm valve (F4) is installed on it. The proportional valve (16), the seventh pneumatic diaphragm valve (F7), the eighth pneumatic diaphragm valve (F8), the ninth pneumatic diaphragm valve (F9) and the eleventh pneumatic diaphragm valve (F11) are used to regulate the membrane system (11). The third pneumatic diaphragm valve (F3) and the sixth pneumatic diaphragm valve (F6) are installed on the feed pipeline of the filtrate tank (15).

2. The method for implementing the automated control equipment for membrane filtration according to claim 1, characterized in that, Includes the following steps: Step S1: Selecting the control mode based on the host computer and sending it to the programmable logic controller; Step S2: The programmable logic controller (PLC) performs logical operations according to the control mode and then generates control instructions for each control component. Step S3: The steps by which the control unit operates according to the control instructions; In step S1, the control modes include production mode, pickling mode, alkaline washing mode, rinsing mode, top washing mode, mixed cleaning mode, and evacuation mode; wherein, the mixed cleaning mode includes any combination of pickling mode, alkaline washing mode, rinsing mode, and evacuation mode in any order. The control components in step S2 include a feed pump, a circulation pump, a dosing pump, a pneumatic diaphragm valve, a proportional valve, and a dosing pump.

3. The method for implementing the automated control equipment for membrane filtration according to claim 2, characterized in that: When the control mode is selected as production mode in step S1, the control command in step S2 includes: opening the first pneumatic diaphragm valve (F1), the second pneumatic diaphragm valve (F2), the third pneumatic diaphragm valve (F3), the fourth pneumatic diaphragm valve (F4) and the proportional valve (16), and then starting the feed pump and the circulation pump in sequence. The opening degree of the proportional valve (16) is controlled by PID, that is, the difference between the current concentrate flow rate and the set flow rate is negatively fed back to control the opening degree of the proportional valve (16); the speed of the feed pump is controlled by PID, that is, the difference between the current filtrate flow rate and the set flow rate is negatively fed back to control the speed of the feed pump.

4. The method for implementing the automated control equipment for membrane filtration according to claim 3, characterized in that: When the control mode is selected as cleaning mode in step S1, the control commands in step S2 include: opening the corresponding valves and water pumps, and automatically stopping the machine after the process requirements are met, as detailed below: The cleaning mode opens the valves and water pumps: the first pneumatic diaphragm valve (F1), the second pneumatic diaphragm valve (F2), the fourth pneumatic diaphragm valve (F4), the sixth pneumatic diaphragm valve (F6), the twelfth pneumatic diaphragm valve (F12), the proportional valve (16), the water supply pump, the feed pump, the circulation pump, and the dosing pump; among them, the opening and closing of the twelfth pneumatic diaphragm valve (F12) is controlled by the liquid level of the circulation tank, that is, when the current liquid level is lower than the low liquid level, the twelfth pneumatic diaphragm valve (F12) opens, and when it is higher than the high liquid level, the twelfth pneumatic diaphragm valve (F12) closes; the opening and closing of the dosing pump is controlled by the pH value of the cleaning solution, that is, in the acid washing mode, when the current pH value is greater than the set value, the dosing pump opens to add acid, and when the current pH value is less than the set value, the dosing pump closes; in the alkaline washing mode, when the current pH value is less than the set value, the dosing pump opens to add alkali, and when the current pH value is greater than or equal to the set value, the dosing pump closes.

5. The method for implementing the automated control equipment for membrane filtration according to claim 3, characterized in that: When the control mode is selected as flushing mode in step S1, the control commands in step S2 include: opening the corresponding valves and water pumps, and automatically stopping the machine after the process requirements are met, as detailed below: Flushing mode opens valves and water pumps: opens the first pneumatic diaphragm valve (F1), the seventh pneumatic diaphragm valve (F7), the eighth pneumatic diaphragm valve (F8), the ninth pneumatic diaphragm valve (F9), the proportional valve (16), the feed pump, and the circulation pump.

6. The method for implementing the automated control device for membrane filtration according to claim 3, characterized in that: When the control mode is selected as top-wash mode in step S1, the control commands in step S2 include: opening the corresponding valves and water pumps, and automatically stopping the machine after the process requirements are met, as detailed below: Top washing mode opens valves and water pumps: opens the first pneumatic diaphragm valve (F1), the second pneumatic diaphragm valve (F2), the fourth pneumatic diaphragm valve (F4), the sixth pneumatic diaphragm valve (F6), the proportional valve (16), the feed pump and the circulation pump.

7. The method for implementing the automated control equipment for membrane filtration according to claim 3, characterized in that: When the control mode is selected as the venting mode in step S1, the control commands in step S2 include: opening the corresponding valves and water pumps, and automatically stopping the machine after the process requirements are met, as detailed below: Vacuum mode valve opening: Open the first pneumatic diaphragm valve (F1), the second pneumatic diaphragm valve (F2), the fourth pneumatic diaphragm valve (F4), the sixth pneumatic diaphragm valve (F6), the seventh pneumatic diaphragm valve (F7), the eighth pneumatic diaphragm valve (F8), the ninth pneumatic diaphragm valve (F9), the tenth pneumatic diaphragm valve (F10), the eleventh pneumatic diaphragm valve (F11) and the proportional valve (16).

8. The method for implementing the automated control device for membrane filtration according to any one of claims 4 to 7, characterized in that: The process requirements include the number of runs and the duration.

9. The method for implementing the automated control device for membrane filtration according to claim 8, characterized in that, It also includes the alarm procedure: (I) If any control component in the membrane filtration automated control equipment malfunctions, an alarm sound and an alarm flash will be emitted; (II) If any component in the membrane filtration unit malfunctions, an alarm sound and an alarm flash will be emitted; (III) If the membrane filter unit stops suddenly, an alarm sound and an alarm flash will be emitted.

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