Control method, device and system of flat bed filtration system

Abstract

The application provides a control method, device and system of a flat bed filtration system, relates to the technical field of dirty liquid filtration, and through real-time liquid level monitoring on a target filtration system, analyzes a liquid level change trend to determine a cooperative adjustment strategy of a paper running speed and a negative pressure parameter, can actively adapt to complex working conditions such as feed flow fluctuation and filter cake resistance change, effectively avoids problems such as material running caused by too high liquid level, slurry overflow caused by too low liquid level, negative pressure leakage and reduced filtration efficiency. At the same time, the control logic of the liquid level monitoring-trend analysis-parameter linkage regulation is constructed, the negative pressure start-stop and paper running triggering do not need manual intervention, the complexity and misoperation risk of manual operation are avoided, and the energy consumption of the constant operation of the negative pressure system is reduced. At the same time, the use state of the filter paper can be adapted to the filtration demand, the filtration precision fluctuation is reduced, the service life of the core component of the equipment is prolonged, and the filtration efficiency, water quality stability and operation economy are considered.

Description

Technical Field

[0001] This invention relates to the field of wastewater filtration technology, and in particular to a control method, apparatus and system for a flat bed filtration system. Background Technology

[0002] In industrial wastewater discharge and environmental sludge purification scenarios, it is necessary to retain solid impurities in the sludge and separate clean water. Existing technologies employ flat-bed filtration systems for sludge filtration. Their core principle relies on negative pressure to drive the sludge through the filter layer to achieve solid-liquid separation. Furthermore, filtration control utilizes three relatively independent modes: level control, paper feeding control, and negative pressure control. For example, a simple timer or differential pressure sensor triggers the paper feeding action. When the sludge reaches a set level, paper feeding begins to continuously keep clean filter paper in contact with the sludge. An alarm is triggered when the level is too high. The negative pressure system operates continuously at a fixed power.

[0003] However, existing liquid level control solutions exhibit a passive response characteristic. Fluctuations in feed flow or changes in filter cake resistance can easily lead to excessively high liquid levels in the filter bed, causing material leakage and slurry overflow, or excessively low liquid levels, resulting in negative pressure leakage and decreased filtration efficiency, demonstrating significant control lag. Furthermore, existing negative pressure systems are typically either always open or rely on manual start-stop operation based on operator experience. The constant power operation of the vacuum pump results in significant energy consumption, and manual start-stop operations are cumbersome and prone to errors, also exhibiting control lag.

[0004] Furthermore, because the filter paper precision is fixed, a high proportion of new filter paper results in fast filtration speed but poor precision, while a high proportion of old filter paper results in high precision but slow speed. This leads to frequent fluctuations in filtration precision within a short period, affecting water quality stability. Moreover, in conventional solutions, the filter paper moves and stops intermittently, especially in large equipment under high liquid levels and high negative pressure conditions. This puts enormous pressure on the mesh chain, idler rollers, and bearings, and frequent starts and stops accelerate the wear of related components, shortening the equipment's lifespan. Summary of the Invention

[0005] The purpose of this invention is to provide a control method, device, and system for a flat bed filtration system, which can reduce operating costs, ensure stable effluent quality, and improve the stability and reliability of the filtration system.

[0006] In a first aspect, the present invention provides a control method for a flatbed filtration system, wherein the method includes: acquiring a real-time liquid level monitoring signal of a target filtration system; determining an adjustment strategy for the paper feed speed parameter and negative pressure parameter of the target filtration system based on the liquid level change trend indicated by the real-time liquid level monitoring signal; and controlling the increase or decrease of the paper feed speed parameter and negative pressure parameter based on the adjustment strategy, so as to perform flatbed filtration treatment on the target material in the target filtration system.

[0007] In conjunction with the first aspect, the present invention provides a first implementation of the first aspect, wherein the step of determining the adjustment strategy of the paper feed speed parameter and negative pressure parameter of the target filtration system based on the liquid level change trend indicated by the real-time liquid level monitoring signal includes: determining the liquid level range to which the real-time liquid level monitoring signal belongs based on the actual liquid level value corresponding to the real-time liquid level monitoring signal; determining the control requirements of the target filtration system based on the liquid level range; determining the parameter adjustment requirements of the target filtration system for the paper feed speed parameter and negative pressure parameter respectively under the control requirements based on the liquid level change trend corresponding to the real-time liquid level monitoring signal; and determining the adjustment strategy of the paper feed speed parameter and negative pressure parameter based on the parameter adjustment requirements.

[0008] In conjunction with the first aspect, this invention provides a second implementation of the first aspect, wherein the liquid level range includes an optimal working range, a high-level warning range, a high-level danger range, and a low-level danger range; each liquid level range does not overlap; wherein the control requirements of the optimal working range include saving filter paper; the control requirements of the high-level warning range include preventing overflow; the control requirements of the high-level danger range include emergency liquid level control; and the control requirements of the low-level danger range include preventing dry-running; the step of determining the parameter adjustment requirements of the target filtration system for the paper feed speed parameter and the negative pressure parameter under the control requirements based on the liquid level change trend corresponding to the real-time liquid level monitoring signal includes: when the real-time liquid level monitoring signal... If the liquid level is in the optimal operating range and the liquid level trend is upward, the parameter adjustment requirement is: prioritize adjusting the negative pressure parameter; if the liquid level trend is downward, prioritize adjusting the paper feed speed parameter; when the real-time liquid level monitoring signal is in the high-level warning range, adjust the negative pressure parameter to the preset maximum negative pressure and adjust the paper feed speed parameter according to the liquid level trend; when the real-time liquid level monitoring signal is in the high-level danger range, adjust the paper feed speed parameter to the preset maximum speed; when the real-time liquid level monitoring signal is in the low-level danger range, turn off the negative pressure parameter control.

[0009] In conjunction with the first aspect, this embodiment of the invention provides a third implementation of the first aspect, wherein the step of prioritizing the adjustment of the negative pressure parameter when the real-time liquid level monitoring signal is in the optimal working range includes: prioritizing the pressurization control of the negative pressure parameter; if the negative pressure parameter is adjusted to a preset upper limit value and the real-time liquid level monitoring signal does not meet the preset liquid level threshold, adjusting the paper feed speed parameter to increase the speed; the step of prioritizing the adjustment of the paper feed speed parameter includes: prioritizing the deceleration adjustment of the paper feed speed parameter; if the paper feed speed parameter is adjusted to a preset lower limit value and the real-time liquid level monitoring signal does not meet the preset liquid level threshold, adjusting the negative pressure parameter to decrease the speed.

[0010] In conjunction with the first aspect, this embodiment of the invention provides a fourth implementation of the first aspect, wherein the step of determining the liquid level interval to which the real-time liquid level monitoring signal belongs based on the actual liquid level value corresponding to the real-time liquid level monitoring signal includes: determining the target liquid level interval that the real-time liquid level monitoring signal is about to enter based on the actual liquid level value; determining whether the actual liquid level value exceeds a preset threshold of the target liquid level interval, and if so, entering the target liquid level interval; wherein the preset threshold exceeds the boundary threshold of the target liquid level interval.

[0011] In conjunction with the first aspect, this invention provides a fifth implementation of the first aspect, wherein the step of increasing or decreasing the paper feed speed parameter and the negative pressure parameter based on an adjustment strategy to perform flatbed filtration treatment on the target material in the target filtration system includes: obtaining the total solid load of the target filtration system; determining the target parameters corresponding to the current paper feed speed parameter and the current negative pressure parameter of the target filtration system based on the total solid load using a preset control strategy; and increasing or decreasing the current paper feed speed parameter and the current negative pressure parameter based on the target parameters.

[0012] In conjunction with the first aspect, the present invention provides a sixth implementation of the first aspect, wherein the method further includes: monitoring the feed pipeline of the target filtration system to determine the feed flow rate and feed suspended solids concentration of the target filtration system; and determining the total solids load of the target filtration system based on the feed flow rate and feed suspended solids concentration.

[0013] In conjunction with the first aspect, this invention provides a seventh implementation of the first aspect, wherein the method further includes: acquiring a first rate of change of the real-time liquid level monitoring signal under the adjustment strategy, and a second rate of change of the negative pressure parameter under the adjustment strategy; and determining the total solid load of the target filtration system based on the first rate of change and the second rate of change.

[0014] Secondly, embodiments of the present invention provide a control device for a flatbed filtration system, wherein the device includes: a data acquisition module for acquiring real-time liquid level monitoring signals of a target filtration system; an execution module for determining adjustment strategies for paper feed speed parameters and negative pressure parameters of the target filtration system based on the liquid level change trend indicated by the real-time liquid level monitoring signals; and a control module for increasing or decreasing the paper feed speed parameters and negative pressure parameters based on the adjustment strategies, so as to perform flatbed filtration treatment on the target material in the target filtration system.

[0015] Thirdly, embodiments of the present invention provide a control system for a flat bed filtration system, wherein the system is equipped with the above-described device for performing the method of any of the above embodiments.

[0016] The embodiments of this invention bring the following beneficial effects: This invention provides a control method, device, and system for a flat-bed filtration system. By real-time monitoring of the target filtration system's liquid level and analyzing the liquid level change trend, a coordinated adjustment strategy for the paper feed speed and negative pressure parameters is determined. This proactively adapts to complex operating conditions such as fluctuations in feed flow rate and changes in filter cake resistance, effectively avoiding problems such as material runoff and slurry overflow caused by excessively high liquid levels, and negative pressure leakage and decreased filtration efficiency caused by excessively low liquid levels. Simultaneously, a control logic of liquid level monitoring, trend analysis, and parameter linkage regulation is constructed, eliminating the need for manual intervention in negative pressure start / stop and paper feed triggering. This avoids the cumbersome nature and risk of misoperation of manual operation, while also reducing energy consumption during constant operation of the negative pressure system. Furthermore, it ensures that the filter paper's usage status adapts to filtration requirements, reduces fluctuations in filtration accuracy, extends the service life of core equipment components, and balances filtration efficiency, water quality stability, and operational economy.

[0017] Other features and advantages of the invention will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A flowchart illustrating a control method for a flatbed filtration system provided in an embodiment of the present invention;

[0021] Figure 2 A flowchart illustrating another control method for a flatbed filtration system provided in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of a control device for a flat bed filtration system provided in an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0026] In industrial wastewater discharge and environmental sludge purification scenarios, it is necessary to retain solid impurities in the sludge and separate clean water. Existing technologies use flat-bed filtration systems for sludge filtration. The core principle relies on negative pressure to drive the sludge through the filter layer to achieve solid-liquid separation: after the sludge enters the filter, negative pressure serves as the core driving force for filtration. A vacuum pump creates a pressure difference under the filter bed, causing the clean liquid to pass through the filter paper and filter cake, while solid impurities are retained in the filter layer. The control system employs three relatively independent modes: liquid level control, paper feeding control, and negative pressure control. Specifically, the paper feeding action is triggered by a simple timer or differential pressure sensor. When the sludge reaches the set liquid level, paper feeding starts to continuously keep the clean filter paper in contact with the sludge. An alarm is triggered when the liquid level is too high. The negative pressure system operates continuously at a fixed power.

[0027] However, the existing technical solution has several shortcomings that urgently need to be addressed: First, the liquid level control exhibits a passive response characteristic. When the feed flow rate fluctuates or the filter cake resistance changes, the liquid level in the filter bed is easily too high, causing material leakage and slurry overflow, or the liquid level is too low, resulting in negative pressure leakage and decreased filtration efficiency, with significant control lag. Second, the negative pressure system control method is unreasonable, usually remaining in a state of constant operation or relying on the operator's experience for manual start-stop. The constant power operation of the vacuum pump results in significant energy consumption, and manual start-stop operation is cumbersome and prone to errors, also exhibiting control lag. For example, if the increase in feed causes the liquid level to rise, and the negative pressure remains unchanged, it will further exacerbate the rise in liquid level. Third, the filtration precision... The first problem is poor filtration stability. Because the filter paper precision is fixed, when the proportion of new filter paper in the vacuum filter is too high, although the filtration speed is faster, the filtration precision is severely damaged. When the proportion of old filter paper is too high, although the filter cake improves the filtration precision, it greatly reduces the filtration speed. This leads to frequent changes in the filtration precision of the filtration system in a short period of time, affecting the stability of the filtered water quality. The second problem is insufficient equipment reliability. In the existing conventional solutions, the filter paper exhibits a stop-and-go phenomenon. Especially in large vacuum filters, when the internal liquid level and negative pressure are high, it will put enormous pressure on the filter's mesh chain, rollers, and bearings at both ends. The frequent start-and-stop of the mesh chain and filter paper will also cause the related drive and load-bearing components to wear out too quickly, shortening the service life of the equipment.

[0028] To address the aforementioned problems, embodiments of the present invention provide a control method, apparatus, and system for a flat bed filtration system, which can reduce operating costs, ensure stable effluent water quality, and improve the stability and reliability of the filtration system.

[0029] To facilitate understanding, the control method of a flat-bed filtration system provided in an embodiment of the present invention will be described first. Figure 1 A flowchart of an embodiment of the present invention is shown, with reference to Figure 1 The method includes the following steps:

[0030] Step S102: Obtain the real-time liquid level monitoring signal of the target filtration system.

[0031] The target filtration system of this invention is used to indicate a flat-bed filtration device applied in industrial wastewater discharge and environmental sewage purification scenarios. Its core function is to drive the sewage through the filter paper (filter layer) by negative pressure, thereby achieving the interception of solid impurities and the separation of clean water. The corresponding real-time liquid level monitoring signal can be collected by a liquid level sensor (such as an ultrasonic sensor, a float sensor, etc.) to reflect the continuous electrical signal of the sewage level height in the filter bed, including data dimensions such as instantaneous liquid level value and liquid level change rate.

[0032] Step S104: Based on the liquid level change trend indicated by the real-time liquid level monitoring signal, determine the adjustment strategy for the paper feeding speed parameter and negative pressure parameter of the target filtration system.

[0033] The liquid level change trend is used to indicate the operating state of the above real-time monitoring signals. For example, the liquid level rises rapidly (rate > preset threshold), the liquid level drops slowly (rate < preset threshold), and the liquid level is stable (fluctuation amplitude ≤ ±5%). The paper feeding speed parameter is used to control the rate of movement of the filter paper in the filtration system, and can directly determine the proportion of new filter paper (fast filtration speed, low precision) and old filter paper (high filtration precision, slow speed) in the filter bed. The negative pressure parameter is used to indicate the operating power of the vacuum pump or the pressure value in the negative pressure chamber, determines the driving force for the waste liquid to pass through the filter layer, and directly affects the filtration efficiency and energy consumption. In the embodiments of the present invention, the paper feeding speed and the negative pressure parameter are adjusted联动 based on the liquid level trend, so that the parameter adjustment is accurately matched with the operating conditions requirements.

[0034] Step S106, based on the adjustment strategy, increase or decrease the paper feeding speed parameter and the negative pressure parameter to perform flat bed filtration on the target material in the target filtration system.

[0035] Based on the determined above adjustment strategy, the paper feeding speed and the negative pressure parameter can be continuously and gradually adjusted through an actuator (such as a variable frequency motor, a solenoid valve), so that the waste liquid is evenly distributed on the filter bed, and passes through the filter paper driven by negative pressure. The solid impurities are intercepted to form a filter cake, and the clear water enters the subsequent treatment link. Different from the passive mode of reprocessing after high liquid level alarm in the prior art, it fundamentally prevents material leakage and slurry overflow.

[0036] Further, based on the above embodiments, the embodiments of the present invention provide another control method for a flat bed filtration system. Figure 2 shows the flowchart of the embodiments of the present invention. Refer to Figure 2 and this method includes the following steps:

[0037] Step S202, obtain the real-time monitoring signal of the liquid level of the target filtration system.

[0038] Step S204, according to the actual liquid level value corresponding to the real-time monitoring signal of the liquid level, determine the liquid level interval to which the real-time monitoring signal of the liquid level belongs.

[0039] Among them, multiple liquid level intervals can be preset according to requirements, and each liquid level interval does not overlap. For example, the liquid level intervals include the optimal working interval, the high level warning interval, the high level danger interval, and the low level danger interval. The corresponding interval thresholds can be the optimal working area (30mm < H ≤ 150mm), the high level warning area (150mm < H ≤ 190mm), the high level danger area (H > 190mm), and the low level danger area (H ≤ 30mm). The basic liquid level interval corresponding to the current working condition can be determined in advance according to the actual liquid level value, and adjusted according to the parameter adjustment strategy corresponding to the corresponding liquid level interval.

[0040] Further, the liquid level may be in a fluctuating state. In the embodiments of the present invention, different thresholds are also set for the entry and exit of the gear positions, forming corresponding buffer zones or hysteresis zones, fundamentally solving the problem of frequent switching jitter of the equipment. In specific implementation, in the embodiments of the present invention, according to the actual liquid level value, the target liquid level range that the real-time liquid level monitoring signal is about to enter is determined. It is judged whether the actual liquid level value exceeds the preset threshold of the target liquid level range. If so, it enters the target liquid level range. Among them, the preset threshold exceeds the boundary threshold of the target liquid level range. Taking the entry of the liquid level into the high gear as an example, in the traditional method, based on the corresponding threshold comparison, for example, when the liquid level > 190 mm, it enters the high gear threshold, and when the liquid level <= 190 mm, it exits the high gear threshold. In this way, when the liquid level fluctuates by 1 mm around 190 mm, the system will switch crazily between the high gear and the intermediate gear.

[0041] The present invention adopts a hysteresis control method and sets preset thresholds for different liquid level ranges respectively. The preset threshold in the embodiments of the present invention exceeds the set threshold of the corresponding target liquid level range. For example, the threshold of the optimal working area is 30 mm < H ≤ 150 mm, the threshold of the high-level warning area is 150 mm < H ≤ xxxx mm, and the threshold of the high-level dangerous area is H > xxxx mm. When the liquid level is about to enter the high-level dangerous area from the high-level warning area, the actual liquid level value needs to be higher than the corresponding lowest boundary value (for example, for 190 mm, the preset threshold is 195 mm) to enter the high-level dangerous area; similarly, the actual liquid level value needs to be lower than the highest boundary value of the original liquid level range (that is, the high-level warning area) (for example, for 190 mm, the corresponding preset threshold is 180 mm) to exit the entered high-level dangerous area. In addition, if the liquid level is about to enter the optimal working area from the high-level warning area, the actual liquid level value needs to be lower than the highest boundary value of the optimal working area to exit the high-level warning area and enter the optimal working area. To sum up, once the liquid level exceeds 195 mm, the system enters the high gear. Subsequently, even if the liquid level immediately starts to drop and is quickly lower than 190 mm, as long as the liquid level does not exceed another preset threshold (that is, it is still above 180 mm), the liquid level is maintained to operate in the high gear. It is not until the liquid level is completely pressed below 180 mm that the system judges to exit the high gear. To sum up, the thresholds for each liquid level range form a liquid level safety buffer zone (such as 180 mm to 195 mm). Within this range, the system switching control is not performed, and it can be maintained to operate stably according to the original control mode, avoiding frequent actions. In addition, by setting the buffer zone, it is ensured that the system must completely control the liquid level to an absolutely safe level (180 mm) before解除高档位状态 is lifted, effectively preventing the recurrence of problems. Moreover, in the embodiments of the present invention, the switching adjustment of the control strategy is determined based on the liquid level state, without relying on time mechanical control, and the parameter adjustment response is more reasonable.

[0042] It should be noted that there is an unclear "xxxx" in the original text which needs to be further clarified for a more accurate translation.In one embodiment, for the working area switching between the low-risk area (H ≤ 30 mm) and the optimal working area (30 mm < H ≤ 150 mm), the corresponding buffer liquid level can be set in the range of 25 - 60 mm. Among them, since the range of the optimal working area is relatively large, the upper limit of the buffer in the low-risk area can be placed within the optimal working area (for example, the buffer gear is set to 40 mm or 60 mm). Taking 60 mm as an example, before the liquid level rises from 0 to 60 mm, it can be defaulted that the system is still in the low-risk area (the corresponding filter paper and negative pressure fan can both be turned off). When the liquid level exceeds 60 mm, the negative pressure fan starts to work. When the liquid level drops below the original working area threshold of 30 mm (such as H ≤ 25 mm), the negative pressure is cancelled to avoid frequent start and stop of the negative pressure fan.

[0043] For the working area gear switching between the optimal working area (30 mm < H ≤ 150 mm) and the high-level warning area (150 mm < H ≤ 190 mm), the corresponding buffer liquid level can be in the range of 120 - 160 mm (that is, the upper and lower limits respectively fall into the respective threshold intervals of the two working areas). For example, when H ≥ 160, it exits the optimal working area; when H ≤ 140, it enters the optimal working area. Since the range of the optimal working area is relatively large, the lower limit of the buffer can be placed as much as possible within the optimal working area; however, due to the control of paper feeding, there is no sudden large increase in speed. For this buffer area, the main purpose is to prevent the negative pressure of the fan from oscillating frequently between the two intervals of 0.15 - 0.2 bar. For example, when the liquid level exceeds 150 mm, the paper feeding is controlled according to PID, and the paper feeding speed is changed according to the change of the liquid level; when the liquid level exceeds 160 mm, the negative pressure increases from 0.15 bar to 0.2 bar. If the liquid level continues to increase, the negative pressure maintains 0.2 bar and the paper feeding speed is further increased; when the liquid level drops to 150 mm or less, the paper feeding runs at the lowest speed. When the liquid level drops to 120 mm or less, the negative pressure drops below 0.15 bar. Avoid non-linear switching of the negative pressure fan.

[0044] For the working area gear switching between the high-level warning area (150 mm < H ≤ 190 mm) and the high-risk area (H > 190 mm), the corresponding buffer liquid level can be set to 180 - 195 mm. This interval is the same as the above example and will not be elaborated here.

[0045] Step S206, determine the control requirements of the target filtration system according to the liquid level interval.

[0046] Step S208, according to the liquid level change trend corresponding to the real-time liquid level monitoring signal, determine the parameter adjustment requirements corresponding to the paper feeding speed parameter and the negative pressure parameter of the target filtration system under the control requirements.

[0047] Among them, the control requirements for the optimal working range include saving filter paper; the control requirements for the high-level warning range include preventing overflow; the control requirements for the high-level danger range include emergency liquid level control; and the control requirements for the low-level danger range include preventing dry-running.

[0048] When the real-time liquid level monitoring signal is within the optimal operating range, and the liquid level change trend is upward, the parameter adjustment target is to prioritize saving filter paper. The corresponding parameter adjustment requirement is to prioritize adjusting the negative pressure parameter. The paper feed speed is maintained at a very low base speed, mainly relying on adjusting the negative pressure (0.05~0.15 bar) to maintain a stable liquid level. In specific implementation, the negative pressure parameter can be prioritized for pressurization control. If the negative pressure parameter is adjusted to the preset upper limit value, and the real-time liquid level monitoring signal does not meet the preset liquid level threshold, the paper feed speed parameter is adjusted to increase its speed. Under this operating condition, this embodiment of the invention uses negative pressure for fine adjustment, and in special cases, it is used in conjunction with coarse adjustment of the paper feed speed. Correspondingly, this embodiment prioritizes adjusting the negative pressure to respond to liquid level changes. When the liquid level rises slowly, the negative pressure is first increased (within the range of 0~0.2 bar) to increase the filtration driving force and lower the liquid level. This increases energy consumption but does not consume filter paper. Furthermore, the system only activates the paper feed motor when the negative pressure has reached its upper limit (e.g., 0.2 bar) and negative pressure alone is insufficient to suppress the rise in liquid level (or the rate of liquid level rise is too fast). This accelerates the paper feed, removes the clogged filter cake, and fundamentally restores filtration capacity. This process consumes filter paper.

[0049] If the liquid level trend indicates a decrease, the parameter adjustment requirement is to prioritize adjusting the paper feed speed parameter. In practice, the paper feed speed parameter can be adjusted by slowing it down first. If the paper feed speed parameter is adjusted to a preset lower limit, and the real-time liquid level monitoring signal does not meet the preset liquid level threshold, the negative pressure parameter is adjusted by reducing it. In practice, when the liquid level decreases, the system prioritizes reducing the paper feed speed (up to the minimum safe speed) to save filter paper. If the liquid level continues to decrease, the negative pressure is further reduced to reduce fan energy consumption, achieving dual energy savings.

[0050] When the real-time liquid level monitoring signal is in the high-level warning zone, the parameter adjustment requirement is to adjust the negative pressure parameter to the preset maximum negative pressure and adjust the paper feed speed parameter according to the liquid level change trend. When the real-time liquid level monitoring signal is in the high-level danger zone, the parameter adjustment requirement is to adjust the paper feed speed parameter to the preset maximum speed. When the real-time liquid level monitoring signal is in the low-level danger zone, the parameter adjustment requirement is to turn off the negative pressure parameter control.

[0051] In specific implementation, the present invention divides the liquid level into multiple regions and adopts different control strategies in different regions: Optimal working area (30mm < H ≤ 150mm): In this region, saving filter paper is the highest priority. The paper feeding speed is maintained at a very low basic speed, and the liquid level is mainly stabilized by adjusting the negative pressure (0.05 - 0.15 bar). High-level warning area (150mm < H ≤ 190mm): In this region, preventing overflow is the highest priority. The control system applies the maximum negative pressure (0.2 bar) and starts to linearly increase the paper feeding speed to quickly reduce the liquid level. High-level dangerous area (H > 190mm): The system triggers an alarm and forces the paper feeding speed to run at the maximum speed (5 m / min) until the liquid level drops back to the safe area. Low-level dangerous area (H ≤ 30mm): The system determines that the liquid level is too low, and there is a risk of "dry pumping" resulting in a decrease in filtration accuracy and damage to the filter paper, and automatically turns off the negative pressure fan.

[0052] Step S210, according to the parameter adjustment requirements, determine the adjustment strategies for the paper feeding speed parameter and the negative pressure parameter.

[0053] Step S212, based on the adjustment strategies, perform increase and decrease control on the paper feeding speed parameter and the negative pressure parameter to perform flat bed filtration on the target material in the target filtration system.

[0054] In specific implementation, the total solid load of the target filtration system can be obtained. Based on the total solid load, the target parameters corresponding to the current paper feeding speed parameter and the current negative pressure parameter of the target filtration system are determined using a preset control strategy. Based on the target parameters, increase and decrease control is respectively performed on the current paper feeding speed parameter and the current negative pressure parameter.

[0055] Specifically, the feed pipeline of the target filtration system can be monitored for incoming material to determine the incoming material flow rate and the incoming material suspended solid concentration of the target filtration system; based on the incoming material flow rate and the incoming material suspended solid concentration, the total solid load of the target filtration system is determined. Among them, the suspended solid content fluctuates between 0.1% - 0.3%, which is the main interference source. Simple feedback control (acting after the liquid level changes) has hysteresis. The embodiment of the present invention performs feedforward parameter control based on the "reasons" causing the liquid level fluctuation. For example, by detecting the interference entering the system in real time (i.e., total solid load = flow rate × suspended solid concentration), before they really affect the controlled variable (liquid level), the required control quantities (paper feeding speed, negative pressure) are calculated in advance and executed. Among them, a flow meter can be installed on the liquid inlet pipeline of the filter to detect the incoming material flow rate Q (m³ / h) in real time. And, an on-line suspended solid concentration meter (a sensor based on optical (laser scattering) or ultrasonic principle) is also installed on the liquid inlet pipeline to detect the concentration C (% or mg / L) in real time.

[0056] Alternatively, control can also be based on the "results". When the liquid level deviates from the set value due to various reasons (such as detection errors, unknown disturbances), the control results of parameter adjustment are corrected. Among them, feedforward can be used to quickly suppress the main disturbance, and feedback control can be used to perform the final precise calibration. The two can be combined for application to obtain a higher control effect. In specific implementation, the first change rate of the real-time liquid level monitoring signal under the adjustment strategy and the second change rate of the negative pressure parameter under the adjustment strategy can be obtained; based on the first change rate and the second change rate, the total solid load of the target filtration system can be determined. In specific implementation, the liquid level (H) and negative pressure (P) values can be read in real time through a controller (such as a PLC or an industrial IPC). The observer inside the controller calculates the change rate based on the historical data of H and P to estimate the current load.

[0057] Among them, according to the preset non-linear control strategy (such as PID) and the above load (such as the estimated load of feedback control or the total solid load of feedforward control), the current optimal negative pressure set value (Pset) and paper feed speed set value (Vset) can be calculated. The controller sends the set values to the fan frequency converter (for adjusting the negative pressure) and the paper feed motor frequency converter (for adjusting the paper feed speed) through analog output or communication to perform control actions. In specific implementation, corresponding to the above optimal working area, the process variable of the non-linear control strategy is the liquid level height H of the sewage in the filter (which can be measured by a liquid level sensor), and a preset optimal liquid level H_setpoint is set (for example, 30mm < H ≤ 150mm of the filter bed depth). Correspondingly, the negative pressure set value P_setpoint in the filter chamber can be output. In one implementation manner, when the liquid level H is within the set range and the liquid level rises slowly, it indicates that the filtration speed cannot keep up with the feeding speed, and the main PID output increases, that is, P_setpoint is increased, and the negative pressure increases, so as to accelerate the filtration speed and make the liquid level drop. When the liquid level H is within the set range and the liquid level drops slowly, it indicates that the filtration speed is faster than the feeding speed, and the main PID output decreases, that is, P_setpoint is decreased, and the negative pressure decreases, so as to reduce the filtration speed and make the liquid level rise.

[0058] For the high-level warning area, the process variable of the above non-linear control strategy is the liquid level height H of the sewage in the filter (which can be measured by a liquid level sensor). Similarly, an optimal liquid level H_setpoint is preset (for example, 150 mm < H ≤ 190 mm of the filter bed depth). The corresponding output is the set value V_setpoint of the paper feeding speed. In one implementation, when the liquid level H is within the set range and the liquid level is rising slowly, it means that the filtration speed cannot keep up with the feeding speed, and the main PID output increases, that is, V_setpoint is increased, the paper feeding speed increases, so as to accelerate the filtration speed and make the liquid level drop. When the liquid level H is within the set range and the liquid level is dropping slowly, it means that the filtration speed is faster than the feeding speed, and the main PID output decreases, that is, V_setpoint is decreased, the paper feeding speed decreases, so as to reduce the filtration speed and make the liquid level rise.

[0059] The embodiments of the present invention have the following great advantages:

[0060] Extreme speed and preventive ability: The control system can start to act before the liquid level has time to change. For a sudden spike in the suspended solid concentration (e.g., instantaneously jumping from 0.1% to 0.3%), the system can "anticipate" the upcoming sharp rise in the liquid level and increase the paper feeding and negative pressure in advance, almost completely eliminating the risk of overflow.

[0061] Greatly improve stability: The fluctuation curve of the liquid level will become very stable, which provides a stable process environment for high-quality filtration.

[0062] Further optimize energy conservation: When it is detected that the inlet load continues to decrease, the system can more "confidently" and quickly reduce the paper feeding speed and negative pressure to the lowest level, because the feed-forward channel has confirmed the reduction of the interference, and there is no need for the feedback control to slowly confirm.

[0063] Furthermore, based on the above embodiments, the embodiments of the present invention also provide a control device for a flat-bed filtration system. Figure 3 The structural schematic diagram of the embodiments of the present invention is shown. Referring to Figure 3 , the device includes: a data acquisition module 100, configured to acquire a real-time monitoring signal of the liquid level of the target filtration system; an execution module 200, configured to determine an adjustment strategy for the paper feeding speed parameter and the negative pressure parameter of the target filtration system based on the liquid level change trend indicated by the real-time monitoring signal of the liquid level; and a control module 300, configured to increase or decrease the paper feeding speed parameter and the negative pressure parameter based on the adjustment strategy, so as to perform flat-bed filtration processing on the target material in the target filtration system.

[0064] The control device for the flat bed filtration system provided in this embodiment of the invention has the same implementation principle and technical effect as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0065] This invention also provides a control system for a flat bed filtration system, which is equipped with the above-described device for executing the methods of any of the above embodiments.

[0066] This invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described... Figures 1 to 2 The steps of any of the methods shown. Embodiments of the present invention also provide a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the above-described steps. Figures 1 to 2 The steps of any of the methods shown. Embodiments of the present invention also provide a structural schematic diagram of an electronic device, such as... Figure 4 The diagram shows the structure of the electronic device, which includes a processor 101 and a memory 100. The memory 100 stores computer-executable instructions that can be executed by the processor 101. The processor 101 executes the computer-executable instructions to implement the above-mentioned... Figures 1 to 2 Any of the methods shown.

[0067] exist Figure 4In the illustrated embodiment, the electronic device further includes a bus 102 and a communication interface 103, wherein the processor 101, the communication interface 103, and the memory 100 are connected via the bus 102. The memory 100 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk drive. Communication between this system network element and at least one other network element is achieved through at least one communication interface 103 (which can be wired or wireless), using the Internet, wide area network, local area network, metropolitan area network, etc. Bus 102 can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, or an AMBA (Advanced Microcontroller Bus Architecture) bus. AMBA defines three types of buses: APB (Advanced Peripheral Bus), AHB (Advanced High-performance Bus), and AXI (Advanced eXtensible Interface). Bus 102 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 4The diagram uses only a single double-headed arrow, but this does not imply a single bus or a single type of bus. Processor 101 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 101 or by instructions in software form. Processor 101 can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of this application can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a mature storage medium in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor 101 reads information from the memory and, in conjunction with its hardware, completes the aforementioned tasks. Figures 1 to 2 any to Figure 2 Any of the methods shown.

[0068] The computer program product of the control method, apparatus, and system of a flat bed filtration system provided in this invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the preceding method embodiments. Specific implementations can be found in the method embodiments and will not be repeated here. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system described above can be referred to the corresponding process in the preceding method embodiments, and will not be repeated here. Furthermore, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0069] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Finally, it should be noted that the above embodiments are merely specific implementations of the invention, used to illustrate the technical solutions of the invention, and not to limit it. The scope of protection of the invention is not limited thereto. Although the invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in this invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, 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 this invention, and should all be covered within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. A control method for a flat-bed filtration system, characterized in that, The method includes: Acquire real-time liquid level monitoring signals from the target filtration system; Based on the liquid level change trend indicated by the real-time liquid level monitoring signal, the adjustment strategies for the paper feeding speed parameters and negative pressure parameters of the target filtration system are determined. Based on the adjustment strategy, the paper feed speed parameter and the negative pressure parameter are increased or decreased to perform flat bed filtration treatment on the target material in the target filtration system. The step of determining the adjustment strategy for the paper feed speed parameters and negative pressure parameters of the target filtration system based on the liquid level change trend indicated by the real-time liquid level monitoring signal includes: Based on the actual liquid level value corresponding to the real-time liquid level monitoring signal, the liquid level range to which the real-time liquid level monitoring signal belongs is determined; wherein, the liquid level range includes the optimal working range, the high-level warning range, the high-level danger range, and the low-level danger range; each of the liquid level ranges does not overlap with the others; Based on the liquid level range, determine the control requirements of the target filtration system; Based on the liquid level change trend corresponding to the real-time liquid level monitoring signal, determine the parameter adjustment requirements of the target filtration system for the paper feed speed parameter and the negative pressure parameter under the control requirements; Based on the parameter adjustment requirements, determine the adjustment strategies for the paper feed speed parameter and the negative pressure parameter; The control requirements for the optimal working zone include saving filter paper; the control requirements for the high-level warning zone include preventing overflow; the control requirements for the high-level danger zone include emergency liquid level control; and the control requirements for the low-level danger zone include preventing dry-running. The steps for determining the parameter adjustment requirements of the target filtration system for the paper feed speed parameter and the negative pressure parameter under the control requirements, based on the liquid level change trend corresponding to the real-time liquid level monitoring signal, include: When the real-time liquid level monitoring signal is within the optimal working range, and the liquid level change trend is characterized by an upward trend, the parameter adjustment requirement is: to prioritize the adjustment of the negative pressure parameter; if the liquid level change trend is characterized by a downward trend, the parameter adjustment requirement is: to prioritize the adjustment of the paper feed speed parameter. When the real-time liquid level monitoring signal is in the high-level warning range, the parameter adjustment requirement is to adjust the negative pressure parameter to the preset maximum negative pressure and adjust the paper feed speed parameter according to the liquid level change trend. When the real-time liquid level monitoring signal is in the high-danger zone, the parameter adjustment requirement is to adjust the paper feed speed parameter to the preset maximum speed. When the real-time liquid level monitoring signal is in the low-risk range, the parameter adjustment requirement is to shut down the negative pressure parameter.

2. The method according to claim 1, characterized in that, When the real-time liquid level monitoring signal is within the optimal operating range, the step of prioritizing the adjustment of the negative pressure parameter includes: The negative pressure parameter is preferentially pressurized. If the negative pressure parameter is adjusted to a preset upper limit value and the real-time liquid level monitoring signal does not meet the preset liquid level threshold, the paper feed speed parameter is adjusted to increase the speed. The steps for prioritizing the adjustment of the paper feed speed parameter include: The paper feed speed parameter is adjusted to slow down first. If the paper feed speed parameter is adjusted to a preset lower limit value and the real-time liquid level monitoring signal does not meet the preset liquid level threshold, the negative pressure parameter is adjusted to reduce pressure.

3. The method according to claim 1, characterized in that, The step of determining the liquid level range to which the real-time liquid level monitoring signal belongs based on the actual liquid level value corresponding to the real-time liquid level monitoring signal includes: Based on the actual liquid level value, determine the target liquid level range that the real-time liquid level monitoring signal is about to enter; Determine whether the actual liquid level value exceeds a preset threshold of the target liquid level range. If so, enter the target liquid level range; wherein the preset threshold exceeds the boundary threshold of the target liquid level range.

4. The method according to claim 1, characterized in that, Based on the adjustment strategy, the steps of increasing or decreasing the paper feed speed parameter and the negative pressure parameter to perform flatbed filtration treatment on the target material in the target filtration system include: Obtain the total solids load of the target filtration system; Based on the total solid load, the target parameters corresponding to the current paper feed speed parameter and the current negative pressure parameter of the target filtration system are determined by using a preset control strategy. Based on the target parameters, the current paper feed speed parameter and the current negative pressure parameter are respectively increased or decreased.

5. The method according to claim 4, characterized in that, The method further includes: The feed pipeline of the target filtration system is monitored to determine the feed flow rate and feed suspended solids concentration of the target filtration system. The total solids load of the target filtration system is determined based on the feed flow rate and the feed suspended solids concentration.

6. The method according to claim 4, characterized in that, The method further includes: The first rate of change of the real-time liquid level monitoring signal under the adjustment strategy is obtained, as well as the second rate of change of the negative pressure parameter under the adjustment strategy; The total solids load of the target filtration system is determined based on the first rate of change and the second rate of change.

7. A control device for a flat bed filtration system, characterized in that, The device includes: The data acquisition module is used to acquire real-time monitoring signals of the liquid level in the target filtration system; The execution module is used to determine the adjustment strategy of the paper feeding speed parameter and negative pressure parameter of the target filtration system based on the liquid level change trend indicated by the real-time liquid level monitoring signal. The control module is used to increase or decrease the paper feed speed parameter and the negative pressure parameter based on the adjustment strategy, so as to perform flat bed filtration treatment on the target material in the target filtration system. The execution module is further configured to: determine the liquid level range to which the real-time liquid level monitoring signal belongs based on the actual liquid level value corresponding to the real-time liquid level monitoring signal; wherein the liquid level range includes an optimal working range, a high-level warning range, a high-level danger range, and a low-level danger range; each of the liquid level ranges is non-overlapping; determine the control requirements of the target filtration system based on the liquid level range; determine the parameter adjustment requirements of the target filtration system for the paper feed speed parameter and the negative pressure parameter respectively under the control requirements based on the liquid level change trend corresponding to the real-time liquid level monitoring signal; and determine the adjustment strategies for the paper feed speed parameter and the negative pressure parameter based on the parameter adjustment requirements. The control requirements for the optimal operating range include saving filter paper; the control requirements for the high-level warning range include preventing overflow; the control requirements for the high-level danger range include emergency liquid level control; and the control requirements for the low-level danger range include preventing dry-running. The execution module is further configured to: When the real-time liquid level monitoring signal is within the optimal working range, and the liquid level change trend is characterized by an upward trend, the parameter adjustment requirement is: to prioritize the adjustment of the negative pressure parameter; if the liquid level change trend is characterized by a downward trend, the parameter adjustment requirement is: to prioritize the adjustment of the paper feed speed parameter. When the real-time liquid level monitoring signal is in the high-level warning range, the parameter adjustment requirement is to adjust the negative pressure parameter to the preset maximum negative pressure and adjust the paper feed speed parameter according to the liquid level change trend. When the real-time liquid level monitoring signal is in the high-danger zone, the parameter adjustment requirement is to adjust the paper feed speed parameter to the preset maximum speed. When the real-time liquid level monitoring signal is in the low-risk range, the parameter adjustment requirement is to shut down the negative pressure parameter.

8. A control system for a flat-bed filtration system, characterized in that, The system is configured with the apparatus of claim 7 for performing the method of any one of claims 1-6.

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