A lye filtration control method and system

Abstract

The present application relates to the technical field of filtration control, and particularly relates to a lye filtration control method and system. The method comprises: obtaining pressure difference data of a filter inlet and outlet of a lye high pressure collected by a differential pressure sensor for online filtration in a period of time; determining a pressure difference growth acceleration of the pressure difference data based on the pressure difference data; comparing the pressure difference growth acceleration with a pre-warning acceleration threshold to obtain a gel comparison result of whether the filter has gel dirt inside; and obtaining a control result of online filtration and cleaning of the filter based on the gel comparison result and a preset cleaning scheme. The present application aims to solve the problem that backwashing by the existing control method cannot effectively remove gel dirt in the filter, resulting in reduced permeability of the filter.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of filtration control, in particular to a lye filtration control method and system. BACKGROUND

[0002] In a manufacturing plant, alkaline solutions are used as a key reaction medium or cleaning agent in a continuous cycle, and suspended solid impurities are mixed in the alkaline solution. At present, an online high-pressure filtration system is used to continuously purify the lye. The filtration system pushes the alkaline solution to a filter element such as a filter screen through a pump at high pressure, and solid particles are intercepted to form a filter cake, and the purified lye continues to flow to the next stage. The system is managed by monitoring the pressure difference between the inlet and outlet of the filter element. When the pressure difference reaches the preset upper limit, the system starts a backwashing program, and the filter cake is flushed by reverse fluid to restore the pressure difference to the initial low level, and then the normal filtration is resumed.

[0003] However, the alkaline solution contains precursor substances in low concentration, fine dispersion or dissolved state, such as organic macromolecules, silicates or hydrated metal oxides. In the high-pressure online filtration system, when the fluid passes through the micro-pores of the filter element, it will experience extremely high shear rate and rapid pressure drop. The precursor substances form a gel dirt that is viscous, tough and usually in a gel state. The gel dirt strongly adheres to the inside of the filter pores, effectively reducing the pore diameter, and even forming a bridge. Although some loose adhered surface particles or gel outer layer can be removed by backwashing, most of the tough substances are still firmly embedded in the filter pore structure. The control system observes a local decrease in pressure difference after backwashing, which is easily misinterpreted as a successful cleaning operation, causing the system to believe that the filter permeability has been fully restored and quickly terminates the backwashing. The gel dirt on the filter screen cannot be effectively removed by backwashing, the permeability of the filter is reduced, and further situations such as ineffective backwashing frequency escalation, increased operation cost, limited production efficiency and system failure are caused. SUMMARY

[0004] The purpose of the present application is to provide a lye filtration control method and system to solve the problem that the gel dirt in the filter cannot be effectively removed by backwashing using the existing control method, resulting in reduced filter permeability.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is as follows: a lye filtration control method, comprising:

[0006] acquiring pressure difference data of two places, i.e. the inlet and outlet of a filter for online filtration of lye high pressure, collected by a differential pressure sensor within a period of time;

[0007] determining the pressure difference growth acceleration of the pressure difference data based on the pressure difference data;

[0008] comparing the pressure difference growth acceleration with a warning acceleration threshold to obtain a gel comparison result of whether the filter has gel dirt inside;

[0009] obtaining a control result of performing online filter cleaning based on the gel comparison result and a preset cleaning scheme.

[0010] Preferably, based on the pressure difference data, the step of determining the pressure difference growth acceleration of the pressure difference data comprises:

[0011] Based on the pressure difference data, confirming a plurality of continuous sampling points in the pressure difference data;

[0012] Filtering the plurality of continuous sampling points to obtain a plurality of filtered sampling points;

[0013] Based on a plurality of the filtered sampling points, determining the growth rate of the pressure difference with time;

[0014] Based on the growth rate of the pressure difference with time, determining the pressure difference growth acceleration of the pressure difference data.

[0015] Preferably, the step of filtering the plurality of continuous sampling points to obtain a plurality of filtered sampling points comprises:

[0016] Performing frequency spectrum analysis on the plurality of continuous sampling points to obtain frequency characteristics of high-frequency background noise;

[0017] Based on the frequency characteristics of the high-frequency background noise, filtering the plurality of continuous sampling points to obtain a plurality of filtered sampling points.

[0018] Preferably, the step of obtaining a control result of performing online filter cleaning based on the gel comparison result and a preset cleaning scheme comprises:

[0019] Based on the gel comparison result, obtaining detection response data collected by the differential pressure sensor on both sides of the filter after driving a detection backwash pulse signal of a detection fluid pre-applied with a preset basic backwash pressure to the filter within a detection time period;

[0020] Analyzing the detection response data to obtain a pressure parameter representing the internal state of the filter;

[0021] Based on the pressure parameter and a preset cleaning scheme, obtaining a control result of performing online filter cleaning.

[0022] Preferably, the step of analyzing the detection response data to obtain a pressure parameter representing the internal state of the filter comprises:

[0023] performing frequency domain transformation on the probe response data to obtain frequency domain information of the probe response data;

[0024] identifying interference frequency component information related to non-gel factors in the frequency domain information;

[0025] removing the interference frequency component information in the frequency domain information to obtain a frequency domain signal after interference processing;

[0026] obtaining a pressure parameter representing an internal state of the filter based on the frequency domain signal after interference processing.

[0027] Preferably, the step of obtaining a control result of online filter cleaning based on the pressure parameter and a preset cleaning scheme comprises:

[0028] determining a physical property of the gel based on the pressure parameter;

[0029] matching a cleaning scheme corresponding to the physical property of the gel in the preset cleaning scheme to obtain a control result of online filter cleaning.

[0030] Preferably, the step of obtaining a control result of online filter cleaning based on the gel comparison result and the preset cleaning scheme further comprises:

[0031] acquiring detection response data collected by a differential pressure sensor on both sides of the filter inlet and outlet after driving a diagnostic backwash pulse signal of a probe fluid to apply a preset basic backwash pressure to the filter for a probe time;

[0032] analyzing the detection response data to obtain a pressure build-up rate of a pressure difference rise curve representing an internal state of the filter;

[0033] comparing the pressure build-up rate with a preset pressure build-up rate to confirm a rate comparison result representing a physical property of the gel;

[0034] obtaining an adjustment result of online filter cleaning based on the rate comparison result and a preset adjustment cleaning strategy.

[0035] Preferably, the step of analyzing the detection response data to obtain a pressure build-up rate of a pressure difference rise curve representing an internal state of the filter comprises:

[0036] performing time domain dynamic analysis on the detection response data to obtain a pressure difference rise curve of the detection response data;

[0037] extracting a pressure build-up rate of the pressure difference rise curve representing an internal state of the filter based on the pressure difference rise curve.

[0038] Preferably, after the step of obtaining the adjustment result of the online filter cleaning of the filter based on the rate comparison result and the preset adjustment cleaning strategy, the method further comprises:

[0039] judging the clean state information of the filter based on the adjustment result of the online filter cleaning of the filter;

[0040] obtaining a clean result of the online filter cleaning of the filter based on the clean state information and a clean state threshold;

[0041] determining online early warning information based on the clean result and a warning threshold.

[0042] The application also provides a lye filter control system, which comprises:

[0043] an acquisition module, configured to acquire pressure difference data of a pressure difference sensor collected at two positions of an inlet and an outlet of a filter for online filtering of lye high pressure within a period of time;

[0044] a determination module, configured to determine a pressure difference growth acceleration of the pressure difference data based on the pressure difference data;

[0045] a comparison module, configured to compare the pressure difference growth acceleration with a warning acceleration threshold to obtain a gel comparison result of whether the filter has gel dirt inside;

[0046] a control module, configured to obtain a control result of the online filter cleaning of the filter based on the gel comparison result and a preset cleaning scheme.

[0047] Compared with the prior art, the lye filter control method and system have the following advantages:

[0048] The application acquires the pressure difference data of the filter at the inlet and the outlet, and determines the pressure difference growth acceleration based on the data. By comparing the pressure difference growth acceleration with the warning acceleration threshold, whether the filter has gel dirt inside can be effectively identified. By combining the gel comparison result with the preset cleaning scheme, the control result of the online filter cleaning of the filter is obtained. The application can realize early warning and accurate cleaning of gel dirt in the lye high pressure online filter system, thereby effectively solving the problems of continuous reduction of filter permeability, escalation of invalid backwashing frequency, limited production efficiency and final system failure caused by accumulation of gel dirt. By effectively removing the gel dirt, the effective permeability of the filter element can be maintained, the passing capacity of the main alkaline solution flow is ensured, the production efficiency of the entire production line is ensured, the service life of the filter is significantly prolonged, and unplanned downtime in the production process is avoided, thereby improving the operation efficiency and reliability of the lye high pressure online filter system. BRIEF DESCRIPTION OF DRAWINGS

[0049] In order to more clearly illustrate the specific embodiments of the present application, the following will briefly introduce the drawings needed to be used in the specific embodiments. In all the drawings, the elements or parts are not necessarily drawn according to the actual proportion.

[0050] Figure 1 The flow chart of the lye filtering control method of the present application.

[0051] Figure 2 The structure block diagram of the lye filtering control system of the present application.

[0052] In the figure: 210, acquisition module; 220, determination module; 230, comparison module; 240, control module.

[0053] The implementation of the functions of the present application and the advantages will be further illustrated with reference to the embodiments and the drawings. DETAILED DESCRIPTION

[0054] The following will disclose multiple embodiments of the present application with the drawings. For the purpose of clear illustration, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit the present application. That is, in some embodiments of the present application, these practical details are not necessary. In addition, for the purpose of simplifying the drawings, some conventional structures and components will be drawn in a simple schematic manner in the drawings.

[0055] It should be noted that all the directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0056] In addition, the descriptions such as "first", "second" and the like in the present application are only for the purpose of description, and do not mean to specially indicate the order or sequence, nor to limit the present application. They are only used to distinguish the components or operations described with the same technical terms, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art. When the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0057] The existing lye high-pressure online filtration system mainly relies on monitoring the pressure difference between the inlet and outlet of the filter to manage system operation when dealing with high-temperature and high-concentration alkaline solutions. When the pressure difference reaches the preset upper limit, the system starts the backwashing program. However, when facing gel dirt caused by high shear rate and rapid pressure drop, the effect is often not good. Gel dirt can firmly embed in the pore structure of the filter, causing traditional backwashing to be ineffective in removing it, which in turn leads to an increase in the frequency of ineffective backwashing, increased operating costs, limited production efficiency, and system failure. This further leads to a continuous decrease in filter permeability, which may eventually require chemical dissolution treatment or replacement of the filter element, resulting in unplanned downtime and high maintenance costs.

[0058] To further understand the content, characteristics and effects of the present application, the following examples are given, and are described in detail as follows with reference to the accompanying drawings:

[0059] Please refer to Figure 1 The present application provides a lye filtration control method, comprising the following steps:

[0060] S100, acquiring pressure difference data of the inlet and outlet of the filter for online filtration of lye high pressure within a period of time. In this embodiment, the lye high-pressure online filtration is a process of continuously purifying high-temperature and high-concentration alkaline solutions without interrupting the production process. This process usually involves removing solid impurities or gel dirt from the alkaline solution under high pressure through a filter. The differential pressure sensor is a device for measuring the pressure difference between two points of a fluid in a pipeline or equipment. Specifically, the differential pressure sensor is used to monitor the pressure difference data of the inlet and outlet of the filter in real time. In this application, the filter is used for online filtration of lye.

[0061] S200, determining the pressure difference growth acceleration of the pressure difference data based on the pressure difference data. Specifically, the pressure difference growth rate can be calculated by numerically differentiating the continuous pressure difference data points, and then the growth rate is numerically differentiated again to obtain the pressure difference growth acceleration. Specifically, the finite difference method can be used, that is, the difference value of the pressure difference of adjacent time points is calculated, and then the rate is obtained by dividing the time interval, and then the same operation is performed on the rate to obtain the acceleration.

[0062] S300, comparing the pressure difference growth acceleration with the early warning acceleration threshold to obtain a gel comparison result of whether the filter has gel dirt inside. The early warning acceleration threshold can be pre-stored in the parameter configuration of the control system. When the calculated pressure difference growth acceleration exceeds the threshold, it is determined that there may be gel dirt inside the filter, and the gel comparison result is that there is gel dirt; otherwise, the gel comparison result is that there is no gel dirt.

[0063] S400, obtaining a control result of performing online filter cleaning based on the gel comparison result and a preset cleaning scheme. The preset cleaning scheme is a cleaning strategy and parameter set preset for different types and degrees of dirt, especially gel dirt. The scheme can include backwash pressure, backwash time, and cleaning medium type, etc. Specifically, if the gel comparison result shows that there is gel dirt, the control system can select a cleaning program specially for gel dirt from the preset cleaning scheme, for example, a cleaning scheme that uses higher pressure backflushing, longer backflushing time, or adds a specific cleaning agent. The control result can be an operation instruction to start the backflushing pump, adjust the valve opening, and control the cleaning agent injection amount, etc.

[0064] In this embodiment, by obtaining the pressure difference data of the filter inlet and outlet collected by the differential pressure sensor within a period of time, real-time and accurate basic information is provided for subsequent analysis. The pressure difference data can reflect the degree of blockage inside the filter, and is a key indicator for judging the running state of the filter. By determining the pressure difference growth acceleration, the signs of gel dirt can be found more sensitively and earlier, because the accumulation of gel dirt will cause the filter pores to shrink rapidly, thereby accelerating the pressure difference rise. The gel comparison result can distinguish whether the pressure difference rise is caused by the accumulation of conventional filter cake or the accelerated rise of pressure difference caused by gel dirt. When the pressure difference growth acceleration exceeds the preset threshold, it can be accurately judged that there may be gel dirt inside the filter, thereby avoiding the situation that gel dirt is misjudged as ordinary filter cake in the traditional method. When gel dirt is confirmed, the traditional backflushing is no longer blindly performed, but the corresponding control instruction is generated according to the preset cleaning scheme specially for gel dirt. For example, higher pressure backflushing can be started, the backflushing time can be extended, or a chemical cleaning agent can be introduced, so as to more effectively remove stubborn gel dirt.

[0065] The present application can realize early warning and accurate cleaning of gel dirt. The frequent occurrence of invalid backflushing in the traditional method is avoided, the waste of backflushing fluid and pumping energy is reduced, and the burden of wastewater treatment is reduced. By effectively removing gel dirt, the effective permeability of the filter screen can be maintained, the passing capacity of the main alkaline solution flow can be ensured, thereby ensuring the production efficiency of the entire production line, significantly prolonging the service life of the filter element, and avoiding unplanned shutdown and high maintenance costs caused by the accumulation of gel dirt.

[0066] In some embodiments of the present application described above, the step of determining the pressure difference growth acceleration of the pressure difference data based on the pressure difference data includes:

[0067] Based on the pressure difference data, a plurality of continuous sampling points in the pressure difference data are confirmed. The plurality of continuous sampling points in the pressure difference data are selected from the pressure difference data collected in a period of time to have a time continuity for subsequent processing. The data for calculation has good time correlation, avoiding the influence of data interruption or abnormal jump on the accuracy of calculation.

[0068] The plurality of continuous sampling points are filtered to obtain a plurality of filtered sampling points. The filtering can use a low-pass filter, a moving average filter, or a Kalman filter, etc. The filtering can smooth the data curve, so that the data more clearly reflects the real change trend of the pressure difference, and eliminates random noise, high-frequency interference or instantaneous fluctuations in the original pressure difference data. A more reliable basis is provided for subsequent rate and acceleration calculation.

[0069] Based on the plurality of filtered sampling points, the growth rate of the pressure difference with time is determined. The growth rate represents the change amount of the pressure difference per unit time, which can be obtained by numerical differentiation or curve fitting of the filtered sampling points. For example, the instantaneous growth rate can be approximated by calculating the ratio of the difference between adjacent filtered sampling points to the corresponding time interval.

[0070] Based on the growth rate of the pressure difference with time, the pressure difference growth acceleration of the pressure difference data is determined. Specifically, the pressure difference growth acceleration is the change of the growth rate with time, reflecting the speed of the change trend of the pressure difference. By further numerical differentiation or trend analysis of the determined growth rate, the pressure difference growth acceleration can be obtained, so that the formation and development speed of the gel dirt inside the filter can be more sensitively captured.

[0071] In this embodiment, by introducing the continuous sampling point confirmation and filtering of the original pressure difference data, the influence of noise and fluctuations in the original data on the accuracy of the pressure difference growth acceleration calculation is effectively avoided. The confirmation of the continuous sampling points ensures the integrity and time correlation of the data sequence, laying a foundation for subsequent analysis. Secondly, the filtering can remove the non-trend interference components in the data, so that the real change trend of the pressure difference can be revealed. Since the data is preprocessed and smoothed, the pressure difference growth rate and the pressure difference growth acceleration calculated based on the processed data can more accurately and stably reflect the actual accumulation speed of the gel dirt inside the filter, thereby avoiding false judgments caused by noise in the original data and improving the sensitivity and reliability of the system for early warning of the gel dirt.

[0072] In some embodiments of the application described above, the step of filtering the plurality of continuous sampling points to obtain a plurality of filtered sampling points comprises:

[0073] The multiple continuous sampling points are subjected to spectral analysis to obtain the frequency characteristics of the high-frequency background noise. Specifically, spectral analysis is a process of converting time-domain signals (i.e., the multiple continuous sampling points in the pressure difference data) into frequency-domain signals to reveal the distribution of different frequency components in the signals. Algorithms such as Fast Fourier Transform can be used to process the continuous sampling points to obtain their frequency spectra. Through analysis of the frequency spectra, various noise components present in the signals, particularly the high-frequency background noise, can be identified. The frequency characteristics of the high-frequency background noise can be understood as the manifestations of these noises in the frequency domain, such as their main frequency range and amplitude distribution, etc.

[0074] Based on the frequency characteristics of the high-frequency background noise, the multiple continuous sampling points are subjected to filtering processing to obtain multiple filtered sampling points. Among them, filtering processing based on the frequency characteristics of the high-frequency background noise is to design and apply corresponding filters according to the frequency characteristics of the identified high-frequency background noise to selectively attenuate or eliminate these noise components. For example, a low-pass filter or a band-stop filter can be used to remove the high-frequency background noise from the original sampling point data, thereby obtaining more pure and accurate filtered sampling points.

[0075] Specifically, when processing the pressure difference data collected by the differential pressure sensor, the multiple continuous sampling point data collected continuously within a period of time are first input into a digital signal processor. The processor performs Fast Fourier Transform on the multiple continuous sampling points to obtain their frequency-domain spectra. By analyzing the frequency-domain spectra, it can be observed that there are obvious energy peaks in a specific high-frequency region, which are identified as the frequency characteristics of the high-frequency background noise. For example, it is identified that the high-frequency background noise is mainly concentrated in the frequency range of 500Hz to 1000Hz. Based on this frequency characteristic, the processor will apply a digital low-pass filter with a cutoff frequency set slightly higher than the effective signal frequency but lower than the starting frequency of the high-frequency background noise, such as 400Hz, or apply a band-stop filter to precisely suppress the frequency components in the range of 500Hz to 1000Hz. After filtering processing, the multiple filtered sampling points will significantly reduce the interference of high-frequency noise, thereby more accurately reflecting the actual pressure difference changes and providing high-quality input data for the subsequent determination of the growth rate of the pressure difference over time and the pressure difference growth acceleration.

[0076] The present application can accurately identify and obtain the frequency characteristics of high-frequency background noise in the pressure difference data by introducing spectrum analysis. Due to the accurate understanding of the noise characteristics, the subsequent filtering process can be more targeted. By filtering based on these frequency characteristics, high-frequency background noise can be effectively separated and removed from the original sampling point data, thereby avoiding the problems of excessive filtering or incomplete filtering that may exist in traditional general filtering methods. Through accurate noise removal, the sampling point data after filtering can more truly reflect the actual pressure difference changes in the caustic lye high-pressure online filtering process, laying a foundation for the accurate calculation of the growth rate and acceleration of the pressure difference over time.

[0077] In some embodiments of the present application, the step of obtaining the control result of the online filter cleaning based on the gel contrast result and the preset cleaning scheme includes:

[0078] Based on the gel contrast result, after driving a detection backwash pulse signal of a detection fluid with a preset basic backwash pressure to the filter for a detection time, the detection response data collected by the differential pressure sensor on both sides of the filter inlet and outlet is obtained. Specifically, when the gel contrast result indicates that there may be gel dirt inside the filter, a detection backwash process is started. The process generates a detection backwash pulse signal by driving a detection fluid with a preset basic backwash pressure to the filter. The detection fluid can be a cleaning fluid compatible with the caustic lye to be filtered, such as pure water, dilute caustic lye or other cleaning agents. The preset basic backwash pressure is an initial backwash pressure applied in the detection phase to cause changes in the internal state of the filter, which is usually lower than the complete backwash pressure required for actual cleaning, and is intended to gently detect the characteristics of the gel without immediately performing a strong cleaning. During the detection backwash pulse signal, the differential pressure sensor on both sides of the filter inlet and outlet continuously collects detection response data. The detection response data contains dynamic response information of the gel dirt inside the filter to the backwash pulse, such as pressure fluctuation and pressure recovery rate, etc.

[0079] The detection response data is analyzed to obtain pressure parameters representing the internal state of the filter. The analysis of the detection response data to obtain pressure parameters representing the internal state of the filter is to process and analyze the collected detection response data to extract quantitative indicators that can reflect the specific physical properties or blockage degree of the gel dirt. The pressure parameters can include but are not limited to the slope of the pressure decay curve, the pressure peak, the pressure recovery time or the pressure response amplitude at a specific frequency, etc. The characteristics of the gel such as viscosity, elasticity or adhesion can be more finely described.

[0080] Based on the pressure parameter and the preset cleaning scheme, a control result of online filter cleaning is obtained. Specifically, based on the pressure parameter and the preset cleaning scheme, the control result of online filter cleaning is obtained by matching the cleaning strategy most suitable for the current gel dirt characteristics in the preset cleaning scheme library according to the specific pressure parameter obtained by analysis. The preset cleaning scheme can be a database containing multiple cleaning modes, different backwashing pressures, backwashing times, or cleaning agent types, etc. Through accurate pressure parameters, the most optimized and most economical cleaning scheme can be selected to avoid excessive cleaning or insufficient cleaning.

[0081] Specifically, when it is confirmed that there is a risk of gel dirt inside the filter through the differential pressure growth acceleration comparison, a detection backwashing process will be immediately started. For example, a pure water detection backwashing pulse signal with a duration of 5 seconds and a preset basic backwashing pressure of 0.5 MPa can be driven. During this period, the differential pressure sensor collects the pressure difference data of the filter inlet and outlet at a sampling frequency of 100 Hz to form detection response data. Subsequently, the detection response data is subjected to Fourier transform to analyze its frequency domain characteristics and identify the amplitude of the specific frequency component related to the gel viscosity, which is taken as the pressure parameter representing the internal state of the filter. If the analysis result shows that the gel has high viscosity, a high-pressure and long-time backwashing scheme will be matched in the preset cleaning scheme library, and the injection of a specific cleaning agent can be combined to ensure efficient removal of stubborn gel. On the contrary, if the pressure parameter indicates that the gel viscosity is low, a relatively mild and short-time backwashing scheme will be selected to avoid excessive cleaning.

[0082] In this embodiment, by introducing the detection backwashing pulse signal and analyzing the detection response data, the problem of being unable to accurately identify the characteristics of the gel dirt by only judging the presence or absence of the gel dirt based on the differential pressure growth acceleration is solved. When it is initially judged that there is gel dirt, a general cleaning scheme is no longer directly executed, but a mild detection backwashing pulse signal is first applied. This detection backwashing pulse signal can interact with the gel dirt inside the filter to produce a unique pressure response. By collecting the detection response data through the differential pressure sensor and conducting in-depth analysis, pressure parameters representing the physical characteristics of the gel dirt can be extracted. For example, gels with different viscosities or adhesion forces will have significant differences in the shape, peak value, or decay rate of their pressure response curves when subjected to backwashing pulses. Fine pressure parameters provide more abundant and accurate basis for subsequent cleaning scheme selection, so that the cleaning control result can more accurately match the actual situation of the current gel dirt.

[0083] In some embodiments of the application described above, the step of analyzing the detection response data to obtain the pressure parameter representing the internal state of the filter comprises:

[0084] The probe response data is subjected to frequency domain transformation to obtain frequency domain information of the probe response data. Specifically, the probe response data is the data of the pressure difference between the inlet and outlet of the filter collected by the differential pressure sensor over time after the probe reverse washing pulse signal is applied. Frequency domain transformation is a process of converting time domain signals into frequency domain signals, which separates different frequency components for identification and processing. In practical applications, frequency domain transformation can be fast Fourier transform or wavelet transform, etc., which decomposes complex time domain signals into superposition of different frequency components, thereby revealing the periodicity or transient characteristics hidden in the signal. The frequency domain information of the probe response data is the distribution of the signal on the frequency axis after frequency domain transformation, which reflects the various frequency components contained in the signal and their corresponding energy or amplitude.

[0085] The frequency domain information related to non-gel factors is identified. Specifically, by pre-calibrating the system or by analyzing historical data, a frequency characteristic library of known interference sources is established, so as to match and identify these interference components in the frequency domain information of the current probe response data. In order to accurately locate and distinguish the non-target signals that affect the judgment of gel dirt.

[0086] The interference frequency component information is removed from the frequency domain information to obtain a frequency domain signal after interference processing. Specifically, by using digital filtering technology such as band-stop filter or notch filter, the identified interference frequency component is filtered out from the frequency domain information. In order to eliminate the influence of interference signals on subsequent pressure parameter calculation, and to ensure that the analyzed signal more purely reflects the gel state inside the filter.

[0087] Based on the frequency domain signal after interference processing, a pressure parameter representing the internal state of the filter is obtained. Specifically, by performing inverse frequency domain transformation on the frequency domain signal after interference processing, it is converted back to a time domain signal, and then the pressure parameter such as pressure decay rate, pressure recovery time or pressure peak value is extracted from the time domain signal. In order to obtain more accurate and reliable pressure parameters for subsequent cleaning control decisions.

[0088] Specifically, in the alkali liquor high-pressure online filtration system, in addition to the signal reflecting the characteristics of the gel dirt, the detection response data collected by the differential pressure sensor also superimposes the vibration noise of a fixed frequency (for example, 50Hz or 60Hz) generated by the operation of the circulating pump and the low-frequency noise generated by the pipeline fluid pulsation. Fast Fourier transform is performed on the collected detection response data to convert it into frequency domain information. In the obtained frequency domain information, it can be observed that there is an obvious energy peak at 50Hz or 60Hz, and a broadband noise in a lower frequency range, which are identified as interference frequency component information related to non-gel factors. In order to remove these interferences, a digital band-stop filter can be designed, the center frequency of which is set to 50Hz or 60Hz, and the bandwidth covers the frequency range of the pump vibration noise; at the same time, a high-pass filter can be designed to filter out the low-frequency fluid pulsation noise. The filters are applied to the frequency domain information of the detection response data, so as to remove the interference frequency component information in the frequency domain information and obtain a frequency domain signal after interference processing. The frequency domain signal after interference processing is inverse Fourier transformed to convert it back to the time domain, and a pressure parameter representing the internal state of the filter is extracted from the time domain signal after interference removal, for example, the slope of the pressure decay curve or the characteristic time of the pressure recovery. In this way, the obtained pressure parameter will more accurately reflect the real situation of the gel dirt inside the filter, providing a reliable basis for subsequent cleaning decisions.

[0089] In this embodiment, the time domain signal is converted into frequency domain information by frequency domain transformation of the detection response data, so that various frequency components contained in the signal can be clearly identified. Since the signal is decomposed into the frequency domain, the interference frequency component information related to non-gel factors is revealed. Through pre-established interference frequency feature library or real-time analysis, the interference components can be accurately identified. Subsequently, by removing these interference frequency component information in the frequency domain, for example, using band-stop filtering technology, the influence of these non-gel factors on the detection response data can be effectively eliminated, so as to obtain a frequency domain signal after interference processing which is more pure and more accurately reflects the state of the gel dirt inside the filter. Finally, based on the frequency domain signal after interference processing, a pressure parameter representing the internal state of the filter is obtained, ensuring that the obtained pressure parameter can more truly reflect the physical characteristics of the gel dirt and avoiding misjudgment caused by interference signals.

[0090] In some embodiments of the above-mentioned embodiments of the present application, the step of obtaining a control result of online filtration and cleaning of the filter based on the pressure parameter and the preset cleaning scheme includes:

[0091] Based on the pressure parameter, the physical characteristics of the gel are determined.

[0092] The cleaning scheme matched with the physical properties of the gel in the preset cleaning scheme is obtained, and a control result of online filter cleaning is obtained.

[0093] Specifically, after obtaining the pressure parameter representing the internal state of the filter, the pressure parameter is used to analyze and infer the physical properties of the gel dirt inside the filter. For example, the amplitude, decay rate, and frequency response of the pressure parameter can be correlated with the viscosity, density, adhesion, and elasticity of the gel. By further analyzing the pressure parameter, it can be determined whether the gel is in a loose, viscous, or hardened state, or other states. The preset cleaning scheme can be understood as a set of pre-set cleaning strategies for different gel physical properties. Once the physical properties of the gel are determined, the cleaning scheme that best matches the current gel physical properties can be selected or generated from the set of preset cleaning schemes. For example, for a gel with high viscosity, a cleaning scheme with higher backwash pressure or longer backwash time can be matched; for a gel with strong adhesion, a cleaning scheme with a specific pulse frequency or fluid composition can be matched. The purpose is to ensure that the selected cleaning scheme can most effectively remove the gel dirt inside the current filter.

[0094] In this embodiment, the pressure parameter obtained by analyzing the detection response data indicates that the gel dirt inside the filter has low viscosity and weak adhesion, which may correspond to a newly formed gel that has not yet fully solidified. At this time, based on this physical property, a relatively mild but high-flow backwash scheme is matched in the preset cleaning scheme, for example, a lower backwash pressure but a shorter pulse duration is used to quickly flush away the loose gel. Conversely, if the pressure parameter analysis result shows that the gel has high viscosity and strong adhesion, it may mean that the gel has been formed for a long time or has stubborn properties. A more powerful cleaning scheme is matched, for example, a higher backwash pressure, a longer backwash duration, and possibly combined with specific cleaning agent injection to effectively dissolve and remove stubborn gel. By deeply analyzing the pressure parameter obtained from the detection response data, the specific physical properties of the gel dirt inside the filter can be identified. Since the physical properties of the gel are accurately determined, a cleaning strategy that matches the gel properties can be selected or generated in the preset cleaning scheme. The cleaning scheme matching method based on the physical properties of the gel avoids the one-size-fits-all problem that may exist in traditional general cleaning schemes, thereby ensuring the accuracy and efficiency of the cleaning process.

[0095] In some embodiments of the above-mentioned embodiments of the present application, after the step of obtaining a control result of online filter cleaning based on the gel comparison result and the preset cleaning scheme, the following steps are further included:

[0096] After driving a diagnostic backwash pulse signal of a probing fluid to the filter to apply a preset basic backwash pressure for a probing time, detection response data collected by the differential pressure sensor between the inlet and outlet of the filter is obtained. Specifically, after the preliminary cleaning control result is implemented, in order to further evaluate the actual cleanliness and the characteristics of the residual gel inside the filter, a short-time low-intensity reverse fluid pulse is applied to the filter. The diagnostic backwash pulse signal is different from the conventional cleaning pulse, and the main purpose is to detect rather than thoroughly clean, so the preset basic backwash pressure and the probing fluid are usually used to avoid unnecessary impact or consumption on the filter. During this process, the detection response data is continuously collected by the differential pressure sensor between the inlet and outlet of the filter, which reflects the transient pressure response of the filter when it is affected by the diagnostic backwash pulse signal, and can indirectly reflect the resistance condition and the adhesion characteristics of the gel inside the filter.

[0097] The pressure build-up rate of the pressure difference rise curve representing the internal state of the filter is obtained by analyzing the detection response data. Specifically, the pressure difference rise curve is the curve of the pressure difference between the inlet and outlet of the filter changing with time under the action of the diagnostic backwash pulse signal. The shape and slope of the curve can reflect the degree of blockage and the physical properties of the gel inside the filter. The pressure build-up rate is the slope of the pressure difference rise curve at a certain stage, and the greater the value, the greater the resistance inside the filter, and there may be more residual gel or the adhesion of the gel is stronger. The purpose is to quantify the resistance change inside the filter and provide a basis for subsequent cleaning adjustment.

[0098] The rate comparison result representing the physical properties of the gel is confirmed by comparing the pressure build-up rate with a preset pressure build-up rate. Specifically, the rate comparison result representing the physical properties of the gel is confirmed by comparing the current pressure build-up rate obtained by analysis with a preset pressure build-up rate. The preset pressure build-up rate can be calibrated based on the response of the filter in a completely clean state or the typical response of a specific gel type. For example, whether the current rate is higher than the preset rate. The comparison result can represent the physical properties of the gel. If the pressure build-up rate is significantly higher than the preset value, it may indicate that there is a large amount of viscous gel inside the filter, or the gel has become more dense.

[0099] Based on the rate comparison result and the preset adjustment cleaning strategy, an adjustment result of online filter cleaning of the filter is obtained. Specifically, based on the rate comparison result and the preset adjustment cleaning strategy, the adjustment result of online filter cleaning of the filter is obtained according to the rate comparison result, and the adjustment measures of the current online filter cleaning scheme are determined by referring to the preset adjustment cleaning strategy. The preset adjustment cleaning strategy can be a series of rules or a lookup table. If the rate comparison result shows that the gel adhesion is strong, the adjustment result can be to increase the backwashing pressure or prolong the backwashing time; if the gel amount is large, the backwashing frequency can be increased. In this way, the intelligent and adaptive adjustment of the cleaning scheme is realized, and the best cleaning effect is achieved to avoid under-cleaning or over-cleaning.

[0100] Specifically, after the filter is subjected to a preliminary backwashing cleaning based on the gel comparison result, it is necessary to further confirm the cleaning effect. At this time, the control system drives to apply a diagnostic backwashing pulse signal with a duration of 5 seconds and a pressure of 0.5 MPa to the filter, and the pressure difference data of the inlet and outlet are collected in real time by the differential pressure sensor. Subsequently, the collected detection response data are analyzed, for example, by fitting the initial slope of the pressure difference rising curve, to obtain the current pressure build-up rate of 0.2 MPa / s. If the preset pressure build-up rate threshold in the preset clean state is 0.1 MPa / s, the current 0.2 MPa / s indicates that there is still a certain amount of gel or the adhesion of the gel is strong inside the filter. Based on this rate comparison result, if the rate is higher than the threshold 100%, the backwashing pressure is increased by 20% and the backwashing time is prolonged by 10 seconds according to the preset adjustment cleaning strategy. In this way, the cleaning scheme can be dynamically adjusted to ensure that the gel is completely removed, thereby achieving the best filtering effect and equipment operating state.

[0101] In this embodiment, by introducing the diagnostic backwashing pulse signal and analyzing the detection response data, the adaptability problem that may exist in the traditional cleaning scheme is effectively solved. Specifically, after the preliminary cleaning control result is implemented, the actual clean state inside the filter and the physical properties of the residual gel can be dynamically evaluated in real time by applying the diagnostic backwashing pulse signal and obtaining the detection response data. The pressure build-up rate as a key indicator can quantitatively reflect the resistance change inside the filter, so that the adhesion degree and properties of the gel can be more accurately judged. Due to the fine diagnostic capability, the subsequent cleaning adjustment can be based on the actual situation, avoiding the under-cleaning or over-cleaning caused by relying only on the preset scheme, thereby improving the pertinence and efficiency of the cleaning.

[0102] In some embodiments of the application described above, the step of analyzing the detection response data to obtain the pressure build-up rate of the pressure difference rising curve representing the internal state of the filter comprises:

[0103] performing time-domain dynamic analysis on the detection response data to obtain a pressure difference rise curve of the detection response data, wherein the detection response data is data of pressure difference between the inlet and outlet of the filter collected by the differential pressure sensor over time after the diagnostic backwashing pulse signal is applied, and the time-domain dynamic analysis on the detection response data is detailed observation and processing of the pressure difference data in the time dimension, specifically including drawing the collected pressure difference data into a time sequence graph, or using signal processing techniques such as moving average, exponential smoothing, etc. to smooth the data and highlight its dynamic trend.

[0104] extracting, based on the pressure difference rise curve, a pressure build-up rate of the pressure difference rise curve that characterizes the internal state of the filter, wherein the pressure build-up rate is a key characteristic parameter of the curve, quantifying the speed of change of the pressure difference over time, and the pressure build-up rate can be obtained by calculating the slope of the pressure difference rise curve within a certain time period, or by fitting a curve model (such as linear fitting, exponential fitting, etc.) to determine its growth parameter. The pressure build-up rate can effectively represent the fluid resistance characteristics inside the filter, especially when there is gel dirt inside the filter, the physical properties of the gel will directly affect the resistance when the fluid passes through, such as viscosity, elasticity and thickness, etc., thereby changing the rate of pressure build-up.

[0105] In this embodiment, by performing time-domain dynamic analysis on the detection response data, the dynamic change process of the pressure difference of the filter under the action of the diagnostic backwashing pulse can be captured in detail, thereby obtaining a pressure difference rise curve with rich information. Since the curve contains dynamic response information of the gel dirt on the fluid resistance, the subsequent pressure build-up rate can be accurately extracted based on the curve. As a dynamic indicator, the rate can more sensitively and accurately reflect the physical properties of the gel dirt inside the filter than the static pressure value, providing a more reliable basis for subsequent cleaning strategy adjustment.

[0106] In some embodiments of the application described above, after the step of comparing the rate with the preset adjustment cleaning strategy to obtain an adjustment result of online filter cleaning of the filter, the method further comprises:

[0107] judging, based on the adjustment result of online filter cleaning of the filter, the clean state information of the filter for filter cleaning, specifically, judging the clean state information of the filter for filter cleaning according to the adjustment result of online filter cleaning, to evaluate the current cleanliness of the filter. For example, the residual dirt inside the filter can be comprehensively judged according to the adjusted cleaning parameters, cleaning duration or differential pressure change before and after cleaning, etc. to obtain a quantitative or qualitative index to reflect the actual cleanliness of the filter after adjustment and cleaning.

[0108] Based on the cleanliness information and the cleanliness threshold, a cleanliness result of the filter performing online filtration cleaning is obtained. The cleanliness threshold can be understood as a standard value preset for measuring the cleanliness degree of the filter. When the obtained cleanliness information is compared with the threshold, it can be determined whether the filter has reached the expected cleanliness level. For example, the cleanliness threshold can be a minimum allowed differential pressure value, a maximum allowed residual amount of dirt, or a specific cleaning efficiency percentage. The purpose of the cleanliness result of the filter performing online filtration cleaning is to determine whether the filter has been successfully cleaned to an acceptable cleanliness level.

[0109] Based on the cleanliness result and the early warning threshold, online early warning information is determined. Specifically, the early warning threshold is a critical value for triggering online early warning. When the cleanliness result indicates that the filter fails to reach the expected cleanliness level, and the degree of uncleanliness exceeds the early warning threshold, online early warning information is determined and issued. For example, the early warning threshold can be set when the cleanliness result indicates that the filter cleanliness is lower than a certain percentage, or when the filter differential pressure is higher than a certain specific value after cleaning. The online early warning information is determined to timely inform the operator or the automatic control system that the filter may have a persistent gel dirt problem or poor cleaning effect, and further manual intervention or more powerful cleaning measures are needed.

[0110] Specifically, after a diagnostic backwash pulse signal, the pressure build-up rate is analyzed based on the detection response data, and compared with the preset pressure build-up rate, the rate comparison result is confirmed, and then based on the preset adjustment cleaning strategy, the adjustment result of the filter performing online filtration cleaning is obtained, such as increasing the backwash pressure by 10% and prolonging the backwash time by 5 seconds. After the adjustment cleaning is performed, the cleanliness information of the filter performing filtration cleaning is immediately determined. Specifically, a cleanliness index can be calculated by measuring the differential pressure of the filter inlet and outlet again and combining the flow data after cleaning. For example, if the differential pressure after cleaning is 0.05 MPa, and the preset cleanliness threshold is 0.03 MPa, it indicates that the filter has not reached the ideal cleanliness state. At this time, based on the cleanliness information and the cleanliness threshold, the cleanliness result of the filter performing online filtration cleaning is unclean. Further, if the degree of uncleanliness (for example, the differential pressure is higher than the threshold value 0.02 MPa) exceeds the preset early warning threshold (for example, the differential pressure is higher than the threshold value 0.01 MPa, which is early warning), online early warning information is immediately determined and issued, such as through audible and visual alarm, sending a message to the control room, or automatically triggering a higher level cleaning program, to remind the operator to perform manual inspection or take more powerful cleaning measures, thereby ensuring the normal operation of the filter.

[0111] In this embodiment, by introducing the judgment and early warning mechanism of the filter cleaning state after obtaining the cleaning adjustment result, the deficiencies of the existing scheme in cleaning effect evaluation and risk warning are effectively made up. Specifically, by judging the cleaning state information, the actual running condition of the filter after adjustment and cleaning can be mastered in real time, and the problem that the actual effect cannot be confirmed only by relying on the cleaning adjustment result is avoided. Further, by comparing the cleaning state information with the preset cleaning state threshold, the system can objectively evaluate whether the cleaning is successful, so as to obtain a clear cleaning result. It is just because of this quantitative evaluation of the cleaning effect that when the cleaning result fails to meet the expectation and exceeds the early warning threshold, the system can timely and accurately determine the online early warning information, so as to prompt the operator or the automatic system to take further intervention measures, and avoid the performance degradation or potential failure of the equipment caused by incomplete cleaning.

[0112] Based on the alkali liquor filtration control method in any one of the above embodiments, please refer to Figure 2 The application also provides an alkali liquor filtration control system, which comprises an acquisition module 210, a determination module 220, a comparison module 230 and a control module 240.

[0113] The acquisition module 210 is used for acquiring pressure difference data of the pressure difference sensor collected from the inlet and outlet of the filter for online filtration of the alkali liquor high pressure in a period of time.

[0114] The determination module 220 is used for determining the pressure difference growth acceleration of the pressure difference data based on the pressure difference data.

[0115] The comparison module 230 is used for comparing the pressure difference growth acceleration with a warning acceleration threshold to obtain a gel comparison result of whether the filter has gel dirt inside.

[0116] The control module 240 is used for obtaining a control result of online filtration and cleaning of the filter based on the gel comparison result and a preset cleaning scheme.

[0117] In this embodiment, the pressure difference data of the filter inlet and outlet collected by the pressure difference sensor within a period of time is acquired by the acquisition module 210, providing real-time and accurate basic information for subsequent analysis. The pressure difference data can reflect the degree of internal filter blockage and is a key indicator for determining the running state of the filter. The determination module 220 determines the pressure difference growth acceleration of the pressure difference data. By monitoring the acceleration, signs of gel dirt can be detected more sensitively and earlier, because the accumulation of gel dirt will cause the filter pores to shrink rapidly, thereby accelerating the pressure difference rise. The comparison module 230 compares the pressure difference growth acceleration with the early warning acceleration threshold to obtain the gel comparison result of whether the filter has gel dirt inside. This allows the system to distinguish between the pressure difference rise caused by conventional filter cake accumulation and the accelerated pressure difference rise caused by gel dirt. When the pressure difference growth acceleration exceeds the preset threshold, the system can accurately determine that there may be gel dirt inside the filter, thereby avoiding the situation in the traditional method where gel dirt is misjudged as ordinary filter cake. Finally, the control module 240 obtains the control result of online filter cleaning of the filter based on the gel comparison result and the preset cleaning scheme, ensuring the pertinence and effectiveness of the cleaning strategy. Once gel dirt is confirmed, the system no longer blindly performs traditional backwashing, but generates corresponding control instructions according to the preset cleaning scheme specifically designed for gel dirt. For example, higher pressure backwashing, longer backwashing time, or the introduction of chemical cleaning agents can be started to more effectively remove stubborn gel dirt. The present application can achieve early warning and accurate cleaning of gel dirt in the caustic lye high-pressure online filtration system. It avoids the frequent occurrence of ineffective backwashing in traditional methods, reduces the waste of backwashing fluid and pumping energy, and reduces the burden of wastewater treatment. More importantly, by effectively removing gel dirt, the present application can maintain the effective permeability of the filter element, ensure the flow capacity of the main alkaline solution, and thus ensure the production efficiency of the entire production line, significantly prolong the service life of the filter element, and avoid unplanned downtime and high maintenance costs caused by gel dirt accumulation.

[0118] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the present application.

Claims

1. A caustic filtration control method characterized by, The method comprises the following steps: acquiring pressure difference data of a filter inlet and outlet of an alkali lye high-pressure online filter collected by a differential pressure sensor within a period of time; determining a pressure difference growth acceleration of the pressure difference data based on the pressure difference data; comparing the pressure difference growth acceleration with a pre-warning acceleration threshold to obtain a gel comparison result of whether the filter has gel dirt inside; obtaining a control result of online filter cleaning of the filter based on the gel comparison result and a preset cleaning scheme; the step of obtaining the control result of online filter cleaning of the filter based on the gel comparison result and the preset cleaning scheme comprises the following steps: acquiring detection response data collected by a differential pressure sensor on both sides of the filter inlet and outlet after driving a detection reverse washing pulse signal of a detection fluid pre-applied to the filter with a preset basic reverse washing pressure within a detection time; analyzing the detection response data to obtain a pressure parameter representing an internal state of the filter; obtaining the control result of online filter cleaning of the filter based on the pressure parameter and the preset cleaning scheme.

2. The caustic filtration control method of claim 1, wherein, The step of determining the pressure difference growth acceleration of the pressure difference data based on the pressure difference data comprises the following steps: confirming a plurality of continuous sampling points in the pressure difference data based on the pressure difference data; filtering the plurality of continuous sampling points to obtain a plurality of filtered sampling points; determining a growth rate of the pressure difference with time based on the plurality of filtered sampling points; determining the pressure difference growth acceleration of the pressure difference data based on the growth rate of the pressure difference with time.

3. The caustic filtration control method of claim 2, wherein, The step of filtering the plurality of continuous sampling points to obtain a plurality of filtered sampling points comprises the following steps: performing frequency spectrum analysis on the plurality of continuous sampling points to obtain frequency characteristics of high-frequency background noise; filtering the plurality of continuous sampling points based on the frequency characteristics of the high-frequency background noise to obtain a plurality of filtered sampling points.

4. The caustic filtration control method of claim 1, wherein, The step of analyzing the detection response data to obtain a pressure parameter representing an internal state of the filter comprises the following steps: performing frequency domain transformation on the detection response data to obtain frequency domain information of the detection response data; identifying interference frequency component information related to non-gel factors in the frequency domain information; removing the interference frequency component information in the frequency domain information to obtain a processed interference frequency domain signal; obtaining the pressure parameter representing the internal state of the filter based on the processed interference frequency domain signal.

5. The caustic filtration control method of claim 1, wherein, The step of obtaining the control result of online filter cleaning of the filter based on the pressure parameter and the preset cleaning scheme comprises the following steps: determining physical characteristics of the gel based on the pressure parameter; matching a cleaning scheme corresponding to the physical characteristics of the gel in the preset cleaning scheme to obtain the control result of online filter cleaning of the filter.

6. The caustic filtration control method of claim 1, wherein, The step of obtaining the control result of online filter cleaning of the filter based on the gel comparison result and the preset cleaning scheme further comprises the following steps: acquiring detection response data collected by a differential pressure sensor on both sides of the filter inlet and outlet after driving a diagnostic reverse washing pulse signal of a detection fluid applied to the filter with a preset basic reverse washing pressure within a detection time; analyzing the detection response data to obtain a pressure build-up rate of a pressure difference rise curve representing an internal state of the filter; comparing the pressure build-up rate with a preset pressure build-up rate to obtain a rate comparison result representing a physical property of the gel; based on the rate comparison result and a preset adjustment cleaning strategy, obtaining an adjustment result of online filter cleaning of the filter.

7. The caustic filtration control method of claim 6, wherein, The step of analyzing the detection response data to obtain a pressure build-up rate of a pressure difference rise curve representing an internal state of the filter includes: performing time-domain dynamic analysis on the detection response data to obtain a pressure difference rise curve of the detection response data; based on the pressure difference rise curve, extracting a pressure build-up rate of a pressure difference rise curve representing an internal state of the filter.

8. The caustic filtration control method of claim 6, wherein, After the step of obtaining an adjustment result of online filter cleaning of the filter based on the rate comparison result and a preset adjustment cleaning strategy, the method further includes: based on the adjustment result of online filter cleaning of the filter, determining clean state information of the filter during filter cleaning; based on the clean state information and a clean state threshold, obtaining a clean result of online filter cleaning of the filter; based on the clean result and a warning threshold, determining online warning information.

9. A caustic filtration control system, characterized by, The system includes: an acquisition module configured to acquire pressure difference data of a filter inlet and outlet of lye high pressure online filtering collected by a differential pressure sensor within a period of time; a determination module configured to determine a pressure difference growth acceleration of the pressure difference data based on the pressure difference data; a comparison module configured to compare the pressure difference growth acceleration with a warning acceleration threshold to obtain a gel comparison result of whether the filter has gel dirt inside; a control module configured to obtain a control result of online filter cleaning of the filter based on the gel comparison result and a preset cleaning scheme; further configured to, based on the gel comparison result, after driving a detection backwash pulse signal of a detection fluid pre-applied to the filter with a preset basic backwash pressure within a detection time, acquire detection response data collected by the differential pressure sensor on both sides of the filter; analyze the detection response data to obtain a pressure parameter representing an internal state of the filter; based on the pressure parameter and a preset cleaning scheme, obtain a control result of online filter cleaning of the filter.

Images