An intelligent control method and system for plate-and-frame filter press

Abstract

The application discloses a kind of plate and frame filter press intelligent control method and system, the method includes: collecting material concentration and liquid level;Control filter press start-stop;Collect feed flow and feed pressure;When feed flow exceeds normal flow, and feed pressure cannot rise after a period of time, determine that pipeline or filter plate leaks, automatically stop feeding and alarm;Calculate the longest filter pressing time required for filter press, predict moisture content;Collect filtrate turbidity and filtrate flow;When filtrate turbidity exceeds rated turbidity, determine as liquid leakage;Difference between filtrate flow and feed flow exceeds rated value, determine as liquid leakage;Collect filter cloth surface image when cleaning each time, automatically determine whether to carry out secondary cleaning, turn into filter pressing, stop and prompt filter cloth replacement;Sensing positioning each filter plate position, and automatically correct filter plate pull skew;Establish plate and frame filter press intelligent analysis and decision model.The application can realize the autonomous control of plate and frame filter press, and completely intelligent operation.

Description

Technical Field

[0001] This invention belongs to the field of automation control, specifically relating to an intelligent control method and system for plate and frame filter presses. Background Technology

[0002] Plate and frame filter press dewatering equipment, also known as plate and frame filter press, is widely used in food, medicine, mining, metallurgy and other industries due to its advantages such as large filtration driving force, high solid content of filter cake, clear filtrate, high solid recovery rate and low consumption of sludge conditioning chemicals. At present, the automatic operation function of the plate and frame filter press body has been realized. Most of the automatic actions are based on the limit switches installed on the body to collect digital signals and output control steps, such as: (1) triggering the plate pulling action according to the limit switch of the main push plate backward stroke; (2) triggering the liquid receiving plate closing action according to the limit switch of the pull plate backward stroke; (3) triggering the filter pressing / rinsing action according to the upper limit switch of the liquid receiving plate; (4) triggering the main push plate depressurization and backward action according to the lower limit switch of the liquid receiving plate; (5) triggering the rinsing rod downward / lifting action according to the upper / lower limit switch of the rinsing rod, etc. In addition, a very small number of actions are output by comparing analog signals such as pressure and time. For example: (1) collecting the pressure of the feed pipe and comparing it with the internal value to trigger the stop feeding action; (2) counting the duration of each step of the plate pulling process to trigger the plate pulling forward / backward action, etc. The above automatic actions only belong to the category of basic automation and are far from intelligent and smart.

[0003] As the main dewatering equipment, plate and frame filter presses still have many problems in actual operation: 1. Low level of automation, incomplete sludge unloading, high labor intensity, and hindering labor efficiency improvement; 2. Frequent leakage and slurry spraying, easily causing pollution to the equipment and workshop environment, which is difficult to improve on-site and poses significant environmental risks; 3. High failure rate of cleaning devices, excessive cleaning water volume, and poor cleaning effect; 4. Few data acquisition points and insufficient dynamic parameters, resulting in basic automation based on simple signal feedback during daily operation, lacking fault diagnosis, status analysis, automatic selection of working mode, and automatic troubleshooting capabilities. Furthermore, due to high working pressure, rapid wear of pipes / filter cloth, easy blockage of the slurry inlet, incomplete filter cloth cleaning, or high water consumption, the failure rate is high, and the sludge moisture content is unstable, making it difficult to achieve fully unattended operation. Summary of the Invention

[0004] The purpose of this invention is to provide an intelligent control method and system for plate and frame filter presses, thereby solving the problem of low automation levels in current plate and frame filter presses.

[0005] The present invention adopts the following technical solution:

[0006] A method for intelligent control of a plate and frame filter press includes the following steps:

[0007] The filter press collects material concentration and liquid level data. When the material concentration and liquid level exceed the set upper limit, the filter press automatically enters the feeding and filtration stage. When the material concentration and liquid level are below the set lower limit, the filter press automatically stops after completing this filtration cycle. When the material concentration and liquid level are between the upper and lower limits, the filter press automatically cycles through feeding and filtration.

[0008] Collect feed flow rate and feed pressure; when the feed flow rate exceeds the normal flow rate and the feed pressure fails to rise after a certain delay, it is determined that there is a leak in the pipeline or filter plate, and the feed is automatically stopped and an alarm is triggered.

[0009] Collect the material concentration c and feed flow rate Q, and combine them with the filter chamber volume V, moisture content m and specific gravity sg of the filter press to calculate the maximum required filtration time t = [V*(1-m)*sg] / c*Q, and set it automatically;

[0010] By collecting the material concentration c and feed flow rate Q, and combining them with the filter chamber volume V and specific gravity sg of the filter press, the moisture content m is predicted as: m = [1 - (c * Q) / sg / V] * 100%;

[0011] Collect the turbidity and flow rate of the filtrate; if the turbidity of the filtrate exceeds the rated turbidity, it is judged as leakage; if the difference between the filtrate flow rate and the feed flow rate exceeds the rated value, it is judged as leakage.

[0012] Each time the filter cloth is cleaned, an image of the filter cloth surface is captured. The image analysis automatically determines whether to perform a second cleaning, switch to filter press, stop the machine, and prompt for filter cloth replacement.

[0013] The sensor locates the position of each filter plate and automatically corrects the tilt of the filter plates by clamping the cleaning trolley and releasing and then pressing the main push plate.

[0014] Establish an intelligent analysis and decision-making model for plate and frame filter presses:

[0015] Based on the changing trends of feed flow rate, feed pressure, and filtrate flow rate, the system determines whether the feed pipe, feed pump, and filter cloth are blocked or damaged, and intelligently selects to flush the pipe and filter cloth. If the flushing is ineffective, the system prompts for maintenance.

[0016] Based on the trends of filtration count, filtrate turbidity, filtrate flow rate, and changes in filter cloth surface images, the service life of the filter cloth is analyzed, and replacement is recommended.

[0017] Based on the magnetic positioning data of the filter plates and the statistics of grating anomalies, the system analyzes the offset and misalignment of the filter plates, intelligently selects to loosen or tighten, and adjusts autonomously. If the adjustment is ineffective, it indicates that the filter press frame is deformed or twisted, indicating a structural safety risk.

[0018] Furthermore, the predicted moisture content is used to optimize and adjust the filter press time.

[0019] Furthermore, the predicted moisture content is used to calculate the amount of oven-dry filter media.

[0020] An intelligent control system for a plate and frame filter press, used to implement the above-described intelligent control method, comprises:

[0021] Material concentration sensor and water level sensor are installed in the thickening tank to collect material concentration and liquid level data;

[0022] The first flow sensor and pressure sensor are installed in the feed pipe to collect the feed flow rate and feed pressure;

[0023] A turbidity sensor and a second flow sensor are installed at the filtrate outlet to collect the turbidity and flow rate of the filtrate.

[0024] A vision sensor, mounted on the cleaning cart, is used to collect images of the filter cloth surface;

[0025] Magnetic and optical grating sensors are installed on the filter plates, frames, and pull-plate trolleys to sense and locate the position of each filter plate.

[0026] The intelligent analysis and decision-making model for plate and frame filter presses is used to receive the collected data and control the filter press according to any one of the intelligent control methods for plate and frame filter presses described above.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] This invention enables autonomous control and fully intelligent operation of plate and frame filter presses. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the input acquisition of the present invention;

[0030] Figure 2 This is a schematic diagram of the intelligent analysis and decision-making model of the present invention;

[0031] Figure 3 This is a schematic diagram of the output execution of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0033] This invention relates to all places where dehydration processes are required to extract materials with high solid content, and more specifically to the need for plate and frame filter press dehydration equipment to achieve fully automated operation and intelligent control and adjustment of each stage.

[0034] This invention targets an integrated intelligent dewatering system. It expands the filter press's external sensing capabilities by adding sensors for flow rate, pressure, and turbidity to the filter press's feed and discharge pipes, sensors for sludge concentration and liquid level to the thickener, and image, magnetic, and grating sensors to the cleaning trolley, filter plates, frame, and pull-plate trolley. The invention also performs correlation analysis between the collected data and the dewatering steps to explore the data's application scope and function. Furthermore, it establishes an intelligent analysis model for the control output of different steps in the plate and frame filter press under multi-parameter conditions. Combining the model analysis results with practical application, corresponding strategies are generated and implemented. Finally, it conducts reliability analysis, develops the integration method, and establishes an intelligent operation control program.

[0035] The technical solution of the present invention is as follows:

[0036] (1) Expand the sensing capabilities at the feed end. Make the feedback of the sludge pretreatment (sludge thickening, which can collect feed concentration and thickening tank level) process before the feed pump digital.

[0037] (2) Filtration process control, intelligent positioning and correction of filter plates, intelligent response to filtrate turbidity, and intelligent judgment and implementation of filter cloth cleaning.

[0038] (3) Intelligent control optimization of the entire dewatering system centered on the filter press. This involves establishing an intelligent analysis model under multiple parameter conditions through comprehensive data collection, analysis, and algorithm optimization. Then, combined with empirical data values ​​from the database, corresponding strategies are generated and implemented, such as... Figure 1 , Figure 2 and Figure 3 As shown, this enables the entire automatic control system of the filter press to possess a higher level of intelligent control capabilities of "intelligent analysis - decision-making - implementation - feedback learning - adjustment - re-implementation", and to achieve the overall integration of the auxiliary facilities around the filter press to form an intelligent dewatering system.

[0039] The embodiments of the present invention are as follows:

[0040] 1. By setting material concentration sensors and water level sensors in the previous process, when the material concentration and liquid level exceed the set upper limit, the filter press automatically enters the feeding and filtration stage; when the material concentration and liquid level are lower than the set lower limit, the filter press automatically stops after completing this filtration; when the material concentration and liquid level are between the upper and lower limits, the filter press automatically cycles through feeding and filtration (the set values ​​are different for different material properties and different tank types).

[0041] 2. By installing flow sensors and pressure sensors in the feed pipe, the feed flow rate is collected and the feed pressure changes are combined to determine whether the feed is normal. If the flow rate exceeds the normal range and the feed pressure fails to rise after a certain delay, it is determined that there is a leak in the pipe or filter plate, and the feed is automatically stopped and an alarm is triggered.

[0042] 3. By collecting material concentration c and feed flow rate Q, combined with filter chamber volume V of the filter press and moisture content m and specific gravity sg of the dewatered sludge, the required maximum filtration time t is calculated and set automatically.

[0043] Calculation formula: [V*(1-m)*sg] / c*Q=t

[0044] 4. The moisture content m is predicted by combining the feed flow rate Q, feed concentration c, and filter chamber volume V of the filter press. If the feed flow rate and filtrate flow rate continuously decrease, the moisture content of the dewatered sludge can be predicted by combining the feed concentration (functions: ① to count the amount of oven-dry sludge; ② to optimize and adjust the filter press time; ③ to provide suggestions for improving the moisture content).

[0045] Calculation formula: [1 - (c*Q) / sg / V] * 100% = m

[0046] 5. By installing turbidity and flow sensors at the filtrate outlet, the turbidity index of the filtrate is detected. If the turbidity exceeds the rated value, it is judged as leakage. If the difference between the filtrate flow rate and the feed flow rate Q exceeds the rated value, it is judged as leakage.

[0047] 6. By installing a vision sensor on the cleaning trolley, images of the filter plate surface are collected each time the machine is cleaned. The image analysis software automatically determines whether to perform a second cleaning, switch to filter press, stop the machine, and prompt for filter cloth replacement.

[0048] Table 1. Logic Analysis Method for Filter Cloth Cleaning

[0049]

[0050] 7. By installing magnetic and optical sensors on the filter plates, frame, and pull plate trolley to locate the position of each filter plate, and by using a trolley clamping and main push plate release and re-clamping method to automatically correct the filter plate tilting problem.

[0051] 8. Establish an intelligent analysis and decision-making model for plate and frame filter press operation modes under multiple parameter conditions based on artificial intelligence technology.

[0052] 8.1 Based on the changing trends of feed flow rate Q, feed pressure P, and filtrate flow rate q each time, analyze the possibility of blockage or damage to the feed pipe, feed pump, and filter cloth, intelligently select pipeline and filter cloth flushing, and prompt maintenance if ineffective;

[0053] Table 2. Blocking Logic Analysis Methods

[0054]

[0055] 8.2 Based on the changing trends of filtration times N, filtrate turbidity NTU, filtrate flow rate q, and changes in the filter cloth visual sensor images, analyze the service life of the filter cloth and suggest replacement.

[0056] Table 3 Logic Analysis Method for Filter Cloth Replacement

[0057]

[0058] 8.3 Based on the magnetic positioning data of the filter plates and the statistics of grating anomalies, analyze the offset and misalignment of the filter plates, intelligently select loosening-tightening, and adjust autonomously. If the adjustment is ineffective, it indicates that the filter press frame may be deformed or twisted, indicating a structural safety risk.

[0059] Table 4 Filter Plate Logic Analysis Method

[0060]

[0061] Those skilled in the art will readily understand that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for intelligent control of a plate and frame filter press, characterized in that, Includes the following steps: The filter press collects material concentration and liquid level data. When the material concentration and liquid level exceed the set upper limit, the filter press automatically enters the feeding and filtration stage. When the material concentration and liquid level are below the set lower limit, the filter press automatically stops after completing this filtration cycle. When the material concentration and liquid level are between the upper and lower limits, the filter press automatically cycles through feeding and filtration. Collect feed flow rate and feed pressure; when the feed flow rate exceeds the normal flow rate and the feed pressure fails to rise after a certain delay, it is determined that there is a leak in the pipeline or filter plate, and the feed is automatically stopped and an alarm is triggered. Collect the material concentration c and feed flow rate Q, and combine them with the filter chamber volume V, moisture content m and specific gravity sg of the filter press to calculate the maximum required filtration time t = [V*(1-m)*sg] / c*Q, and set it automatically; Collect the material concentration c and feed flow rate Q, and combine them with the filter chamber volume V and specific gravity sg of the filter press to predict the moisture content m = [1-(c*Q) / sg / V]*100%; Collect the turbidity and flow rate of the filtrate; if the turbidity of the filtrate exceeds the rated turbidity, it is judged as leakage; if the difference between the filtrate flow rate and the feed flow rate exceeds the rated value, it is judged as leakage. Each time the filter cloth is cleaned, an image of the filter cloth surface is captured. The image analysis automatically determines whether to perform a second cleaning, switch to filter press, stop the machine, and prompt for filter cloth replacement. The sensor locates the position of each filter plate and automatically corrects the tilt of the filter plates by clamping the cleaning trolley and releasing and then pressing the main push plate. Establish an intelligent analysis and decision-making model for plate and frame filter presses: Based on the changing trends of feed flow rate, feed pressure, and filtrate flow rate, the system determines whether the feed pipe, feed pump, and filter cloth are blocked or damaged, and intelligently selects to flush the pipe and filter cloth. If the flushing is ineffective, the system prompts for maintenance. Based on the trends of filtration count, filtrate turbidity, filtrate flow rate, and changes in filter cloth surface images, the service life of the filter cloth is analyzed, and replacement is recommended. Based on the magnetic positioning data of the filter plates and the statistics of grating anomalies, the system analyzes the offset and misalignment of the filter plates, intelligently selects to loosen or tighten, and adjusts autonomously. If the adjustment is ineffective, it indicates that the filter press frame is deformed or twisted, indicating a structural safety risk.

2. The intelligent control method for a plate and frame filter press according to claim 1, characterized in that, Predicted moisture content is used to optimize and adjust filter press time.

3. The intelligent control method for a plate and frame filter press according to claim 1, characterized in that, Predicted moisture content is used to calculate the amount of oven-dry filter media.

4. An intelligent control system for a plate and frame filter press for implementing the intelligent control method for a plate and frame filter press according to any one of claims 1 to 3, characterized in that, The system includes: Material concentration sensor and water level sensor are installed in the thickening tank to collect material concentration and liquid level data; The first flow sensor and pressure sensor are installed in the feed pipe to collect the feed flow rate and feed pressure; A turbidity sensor and a second flow sensor are installed at the filtrate outlet to collect the turbidity and flow rate of the filtrate. A vision sensor, mounted on the cleaning cart, is used to collect images of the filter cloth surface; Magnetic and optical grating sensors are installed on the filter plates, frames, and pull-plate trolleys to sense and locate the position of each filter plate. A plate and frame filter press intelligent analysis and decision model is used to receive collected data and control the filter press according to any one of claims 1 to 3.

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