High-temperature-resistant maintenance-free nanofiltration dust filtration system and method

Abstract

The application discloses a kind of high-temperature-resistant maintenance-free nanometer dust filtering systems and methods, belong to dust filtering system technical field.System includes dust filtering main body, nanometer ceramic filter element assembly, automatic backflush system and control system.Nanometer ceramic filter element is sequentially arranged outer coarse filter layer, middle layer medium filter layer and inner layer fine filter layer from outside to inside, form radial gradient pore size structure, realize dust grading interception.Automatic backflush system adopts double electromagnetic pulse valve series configuration, form first high-pressure impact stripping, after large-flow removal double-peak collaborative backflush airflow.Control system continuously collects differential pressure data and calculates differential pressure change rate, according to differential pressure change rate predicts the remaining time to reach differential pressure threshold and judges backflush trigger timing, realize self-adapting ash removal control, while calculating the differential pressure recovery rate before and after backflush and automatically adjusting backflush parameters.The application realizes the efficient purification of high-temperature dust-containing gas and the long-term maintenance-free operation of the system, significantly prolongs the service life of filter element.

Description

Technical Field

[0001] This invention relates to the field of dust filtration system technology, specifically to a high-temperature resistant, maintenance-free nano dust filtration system and method. Background Technology

[0002] In high-temperature industrial processes such as iron and steel smelting, non-ferrous metal smelting, cement production, and waste incineration, large amounts of dust-laden high-temperature flue gas are generated. Direct emission of these gases without treatment not only causes severe air pollution but also results in the loss of heat energy and valuable materials. Therefore, the purification of high-temperature dust-laden gases is a crucial step in industrial production. High-temperature dust filtration systems, as effective gas-solid separation devices, filter and purify dust-laden gases in high-temperature environments, ensuring that the outlet gas meets emission standards or process requirements, while simultaneously recovering valuable dust materials. High-temperature dust filtration systems typically use high-temperature resistant ceramic or metal filter elements as the filter media, trapping dust particles through surface filtration. With increasingly stringent environmental protection requirements and the continuous development of industrial production, higher demands are being placed on the filtration efficiency, operational stability, service life, and maintenance costs of high-temperature dust filtration systems.

[0003] However, existing high-temperature dust filtration systems still face numerous technical challenges in practical applications. Traditional ceramic filter elements typically employ a uniform pore structure with a single pore size. Large and fine dust particles arrive at the filter surface simultaneously, with the large particles directly clogging the pores and causing rapid accumulation of dust to form a dense dust cake. This prevents the filter's dust-holding capacity from being fully utilized. Because the internal pore space of the filter element fails to effectively participate in filtration and dust holding, the actual dust-holding capacity of a single-pore size filter element is far lower than its theoretical capacity. This leads to a rapid increase in pressure differential, frequent backflushing, and a significantly shortened filter lifespan, making it difficult for the system to operate stably under high dust concentration conditions for extended periods. Furthermore, the inner surface of existing ceramic filter elements is typically in its original ceramic material state, with high surface energy. This results in strong van der Waals forces and electrostatic attraction between the ceramic material and dust particles, causing a strong adhesion between the dust cake and the filter surface. During backflushing cleaning, even with high backflushing pressure, the dust cake layer is difficult to completely peel off. Some dust always remains on the filter element surface or embedded deep within the filter element pores. This residual dust gradually accumulates after multiple filtration and backflushing cycles, occupying the effective filtration area and dust holding space of the filter element. This leads to a continuous increase in residual pressure difference after backflushing and a continuous decrease in pressure difference recovery rate. After long-term operation, irreversible deep blockage will form inside the filter element, severely affecting filtration performance and service life. Dust adhesion also increases backflushing energy consumption, as higher backflushing pressure and longer backflushing time are required to achieve the desired cleaning effect. The timing of backflushing cleaning has a significant impact on system performance. Traditional high-temperature dust filtration systems often use a fixed pressure difference threshold to trigger backflushing control, meaning that backflushing is triggered immediately when the pressure difference across the filter element reaches a preset threshold. This control method is a passive response mechanism, unable to predict pressure difference changes and blockage rates, and cannot intervene in cleaning in advance based on the actual blockage situation. Under certain operating conditions, when dust concentration suddenly increases or dust properties change, the filter element can quickly become clogged. When the pressure difference reaches the threshold to trigger backflushing, the filter element is already deeply clogged, and the dust cake layer has become thick and compacted. At this point, the difficulty of backflushing cleaning increases significantly, and the cleaning effect decreases markedly. Forceful backflushing in a deeply clogged state can also cause mechanical damage to the filter element, accelerating its fatigue failure. Fixed threshold triggering methods lack adaptability and cannot adopt corresponding cleaning strategies for different clogging stages, making it difficult to achieve the optimal balance between cleaning effect and energy consumption. The characteristics of the backflushing airflow directly determine the cleaning effect. Existing backflushing systems typically use a single electromagnetic pulse valve to generate a single-peak pulse airflow for backflushing cleaning. The design of the single-peak pulse needs to consider both dust cake layer peeling and dust removal, therefore, trade-offs must be made in parameters such as pulse pressure, flow rate, and duration.If the pulse pressure is set too high to enhance the stripping ability, the flow rate is relatively small and the duration is short, resulting in the stripped dust not being completely blown away from the filter element, and some dust will be redeposited on the filter element surface. If the pulse pressure is set too low to increase the flow rate and duration to improve the cleaning effect, the impact stripping ability on the dust cake layer is insufficient, and the dust removal is incomplete. The single-peak backflushing method cannot simultaneously optimize the stripping and cleaning processes, limiting the thoroughness of dust removal and affecting the long-term operating performance of the system. Traditional maintenance management methods often adopt a fixed-cycle filter element replacement strategy, setting the replacement cycle based on experience, and replacing the filter element regardless of its actual condition upon expiration. Since the actual decay rate of the filter element varies greatly under different operating conditions and conditions, the fixed cycle cannot adapt to the actual situation. It may be necessary to replace the filter element when it still has a long remaining lifespan, resulting in wasted resources and increased maintenance costs. At the same time, there may be cases where the filter element has been severely degraded or even failed but has not yet reached the replacement cycle, resulting in substandard filtration effect or filter element damage leading to production accidents. The existing system lacks real-time monitoring and comprehensive evaluation of the filter element's health status, making it impossible to accurately predict the filter element's remaining service life. Maintenance personnel find it difficult to prepare for replacement in advance, affecting the rational arrangement of production plans.

[0004] Therefore, there is an urgent need to develop a high-temperature resistant, maintenance-free nanofiltration system and method, and to optimize the system from multiple aspects such as filter element structure, surface functionalization, control method and life management, so as to solve the above-mentioned technical problems and achieve efficient purification of high-temperature dust-laden gas and long-term maintenance-free operation of the system. Summary of the Invention

[0005] To address the problems existing in the background technology, the present invention provides a high-temperature resistant, maintenance-free nano dust filtration system, comprising a dust filter body, a nano ceramic filter element assembly, an automatic backflushing system, and a control system;

[0006] The dust filter body includes an air inlet chamber, a filter chamber, and an air outlet chamber, which are separated by a partition and connected in sequence. The air inlet chamber is provided with an air inlet, the air outlet chamber is provided with an air outlet, and the bottom of the dust filter body is provided with a dust hopper, and the bottom of the dust hopper is provided with a dust discharge valve.

[0007] The nano-ceramic filter element assembly includes multiple radial gradient pore size nano-ceramic filter elements. Each filter element has a cylindrical structure and is installed in the filter chamber. The two ends of the filter element are respectively sealed to the air inlet chamber and the air outlet chamber. Each filter element includes an outer coarse filtration layer, a middle medium filtration layer and an inner fine filtration layer from the outside to the inside. The average pore size of the three layers decreases sequentially. The inner surface of the filter element is coated with a dust-repellent nano-composite coating.

[0008] The automatic backflush system includes a high-pressure air source, a backflush air path, a first electromagnetic pulse valve, a second electromagnetic pulse valve, a backflush nozzle, and a differential pressure sensor. The high-pressure air source is connected in series with the first electromagnetic pulse valve and the second electromagnetic pulse valve through the backflush air path. The second electromagnetic pulse valve is connected to the backflush nozzle through the backflush air path. The outlet of the backflush nozzle faces the inner surface of the filter element. The two measuring ports of the differential pressure sensor are respectively located on the outer and inner sides of the filter element.

[0009] The control system is electrically connected to the differential pressure sensor, the first electromagnetic pulse valve, and the second electromagnetic pulse valve. The control system continuously collects differential pressure data and calculates the differential pressure change rate. Based on the differential pressure change rate, it predicts the remaining time to reach the differential pressure threshold and determines the backflush triggering timing. It controls the opening sequence of the first electromagnetic pulse valve and the second electromagnetic pulse valve to form a double-peak pulse backflush airflow. It calculates the differential pressure recovery rate before and after backflush and adjusts the backflush parameters based on the evaluation results. It collects multiple characteristic parameters to calculate the filter element health score and predict the remaining service life.

[0010] Furthermore, the control system includes a PLC controller, a touch screen, an alarm module, a data acquisition module, a differential pressure change rate calculation unit, a backflushing trigger judgment unit, a backflushing timing control unit, a backflushing effect evaluation unit, and a filter element life prediction unit. The touch screen is connected to the PLC controller for setting operating parameters and displaying real-time data. The alarm module is connected to the PLC controller for abnormal state alarms. The ash discharge valve is controlled by the PLC controller. The data acquisition module is connected to the differential pressure sensor signal for continuously acquiring differential pressure data. The differential pressure change rate calculation unit is connected to the data acquisition module. The backflushing trigger judgment unit is connected to the differential pressure change rate calculation unit. The unit connection is used to predict the remaining time to reach the differential pressure threshold based on the differential pressure change rate and to determine the backflush triggering timing. The backflush timing control unit is connected to the PLC controller and electrically connected to the first electromagnetic pulse valve and the second electromagnetic pulse valve respectively to independently control the opening time and opening duration of the two electromagnetic pulse valves. The backflush effect evaluation unit is connected to the data acquisition module and the backflush timing control unit to calculate the differential pressure recovery rate before and after backflush and send parameter adjustment instructions to the backflush timing control unit according to the evaluation results. The filter element life prediction unit is connected to the data acquisition module to collect multiple characteristic parameters to calculate the filter element health score and predict the remaining service life.

[0011] Furthermore, the outer coarse filter layer, the middle medium filter layer, and the inner fine filter layer are integrally sintered, with the outer coarse filter layer used for interception. The above-mentioned large particulate dust, the middle medium filter layer is used to intercept it. Medium-grade dust, the inner fine filter layer is used to trap... Fine dust particles are filtered through a three-layer gradient pore size gradation system to prevent large dust particles from directly clogging the fine pores of the inner layer; the dust-repellent nanocomposite coating is chemically bonded to the inner surface of the filter element, and the low surface energy groups on its surface reduce the adhesion between the dust and the inner surface of the filter element, allowing the dust cake to peel off during backflushing; the valve port size of the second electromagnetic pulse valve is larger than that of the first electromagnetic pulse valve, forming different pressure characteristics of the first peak stripping pulse and the second peak removal pulse.

[0012] Furthermore, the filter cartridge life prediction unit includes a feature parameter acquisition module, a health rating module, and a remaining life calculation module. The feature parameter acquisition module is connected to the data acquisition module and the temperature sensor signal to acquire residual pressure difference after backflushing, pressure difference recovery rate, cumulative number of backflushing cycles, average operating temperature, and pressure difference rise rate. The health rating module is connected to the feature parameter acquisition module to perform normalized scoring calculations on each feature parameter and calculate the filter cartridge health rating through weighted summation. The remaining life calculation module is connected to the health rating module to calculate and predict the remaining service life based on the health rating and provide early warning.

[0013] This invention also provides a high-temperature resistant, maintenance-free nanofiltration method, which is performed according to the following steps:

[0014] S1: Set operating parameters and measure the initial differential pressure of the clean filter element via the touch screen;

[0015] S2: Start the filtration cycle. Dust-laden gas enters the filtration chamber from the inlet chamber and passes through the three layers of the filter element for graded interception. Clean gas is discharged from the outlet chamber.

[0016] S3: The differential pressure sensor continuously measures the pressure difference across the filter element. The data acquisition module collects the differential pressure data and transmits it to the differential pressure change rate calculation unit for differential pressure change rate calculation.

[0017] S4: The backflush triggering judgment unit predicts the remaining time to reach the pressure difference threshold based on the pressure difference change rate, and determines the timing of backflush triggering based on the magnitude of the pressure difference change rate to determine the blockage stage.

[0018] S5: After receiving the backflush trigger signal, the backflush timing control unit controls the backflush process. First, it closes the intake valve, and then controls the first electromagnetic pulse valve and the second electromagnetic pulse valve to open and close in sequence according to the set timing to form a double-peak coordinated backflush airflow. After the backflush is completed, the intake valve is reopened.

[0019] S6: The backflush effect evaluation unit collects the pressure difference value before and after backflush, calculates the pressure difference recovery rate, and adjusts the pressure and duration parameters of the next backflush according to the magnitude of the pressure difference recovery rate.

[0020] S7: The filter life prediction unit collects multiple feature parameters, calculates the filter health score using a weighted scoring method, and predicts the remaining service life of the filter based on the health score to issue an early warning.

[0021] S8: Return to step S2 to continue the filtration cycle until the filter health score drops to the scrap threshold, prompting you to replace the filter.

[0022] Furthermore, step S1 includes the following specific operations:

[0023] S11: Input differential pressure threshold via touchscreen ,in This is the differential pressure threshold, in Pa, with a set range of 500-800 Pa.

[0024] S12: Input the threshold for the rate of change of rapid choking pressure differential. ,in The threshold for the rate of change of differential pressure during rapid blockage, in Pa / s, is set to 1.5 Pa / s.

[0025] S13: Input the threshold for the rate of change of slow blockage pressure differential ,in The threshold for the rate of change of differential pressure during slow blockage, in Pa / s, is set to 0.5 Pa / s.

[0026] S14: Input the upper limit of the backflush interval time ,in This is the upper limit of the backflush interval time, in minutes, with a setting range of 10-60 minutes;

[0027] S15: Start the system and introduce clean gas at the rated flow rate in clean mode. The differential pressure sensor measures the pressure difference across the filter element at this time, and the PLC controller records this pressure difference as the initial pressure difference. ,in This represents the initial pressure difference, in Pa; system initialization and baseline value establishment are completed.

[0028] Furthermore, step S3 includes the following specific operations:

[0029] S31: The differential pressure sensor continuously measures the pressure difference between the outer and inner sides of the filter element with a sampling period of 1 second to obtain the real-time differential pressure value. ,in This represents the pressure difference at the current moment, in Pa.

[0030] S32: The data acquisition module transmits the differential pressure data to the differential pressure change rate calculation unit;

[0031] S33: The pressure difference change rate calculation unit uses moving average filtering and differential algorithm to calculate the pressure difference change rate. First, it calculates the moving average of the pressure difference at the current moment. ,in This represents the pressure difference at the current moment, in Pa. This is the pressure difference value from the previous second, in Pa. This is the pressure difference value for the first two seconds, in Pa. This is the pressure difference value for the first three seconds, in Pa. The pressure difference is the value over the first four seconds, in Pa; 5 is the size of the moving average window. The moving average of the differential pressure at the current moment, in Pa; then calculate the rate of change of differential pressure. ,in This is the moving average of the differential pressure at the current moment, in Pa. The moving average of the differential pressure 5 seconds ago, in Pa; 5 represents the time interval, in seconds. This is the rate of change of pressure difference, in Pa / s;

[0032] Real-time monitoring of differential pressure change trends.

[0033] Furthermore, step S4 includes the following specific operations:

[0034] S41: The backflush trigger judgment unit obtains the current differential pressure change rate from the differential pressure change rate calculation unit. and current pressure difference ,in This represents the current rate of change of differential pressure, in Pa / s. This is the current pressure difference, in Pa.

[0035] S42: Calculate the arithmetic mean of the rate of change of pressure difference for the most recent 10 samples. ,in This represents the average rate of change of pressure difference, in Pa / s.

[0036] S43: Calculate the remaining forecast time based on the linear forecasting model. ,in This is the differential pressure threshold, in Pa. This is the current pressure difference, in Pa. This represents the average rate of change of pressure difference, in Pa / s. To predict the remaining time, the unit is seconds; if If so, it will directly trigger a backflush;

[0037] S44: Determine the current rate of change of differential pressure relative to the threshold. , The relationship, among which The threshold for the rate of change of differential pressure during rapid blockage, in Pa / s; The threshold for the rate of change of differential pressure during slow blockage, in Pa / s;

[0038] S45: If It is determined to be in the rapid congestion phase, when achieve A pre-flush trigger signal is issued at the appropriate time;

[0039] S46: If This is determined to be a normal congestion phase. achieve A backflush trigger signal is issued at the appropriate time;

[0040] S47: If It is determined to be in the slow congestion stage. achieve A backflush trigger signal is issued at the appropriate time;

[0041] S48: Or when the runtime reaches Regardless of the pressure difference, a backflush trigger signal is issued, in which... This is the upper limit of the backflush interval time, in minutes;

[0042] This allows for early dust removal when the filter element is only slightly clogged, preventing deep clogging from reducing the backflushing effect.

[0043] Furthermore, step S6 includes the following specific operations:

[0044] S61: Before step S5 begins, the backflush effect evaluation unit obtains the current differential pressure value from the data acquisition module and records it as the differential pressure before backflush. ,in The pressure difference before backflushing is expressed in Pa.

[0045] S62: After step S5 ends and the filtration operation stabilizes, obtain the current differential pressure value from the data acquisition module and record it as the differential pressure after backflushing. ,in This represents the pressure difference after backflushing, in Pa.

[0046] S63: Calculate the differential pressure recovery rate ,in The pressure difference before backflushing is expressed in Pa. This represents the pressure difference after backflushing, in Pa. This is the initial pressure difference, in Pa. The differential pressure recovery rate is expressed in % (%).

[0047] S64: Set target recovery rate Calculation error ,in The target recovery rate is expressed in % (%). The error is expressed in %;

[0048] S65: Adjust the backflush parameters based on the error, and calculate the backflush pressure adjustment amount. ,in This is the proportionality constant, set to 0.1, and is dimensionless. This is the backflush pressure adjustment amount, in %; then adjust the first peak pressure of the next backflush to... The second peak pressure is ,in The pressure at the first peak is measured in Pa. The pressure of the second peak is expressed in Pa; the duration of the second peak is also adjusted. ,in The duration of the second peak is expressed in seconds. The error is expressed in %;

[0049] S66: Completes adaptive parameter optimization based on backflushing effect to achieve the optimal balance between dust removal effect and energy consumption.

[0050] Furthermore, step S7 includes the following specific operations:

[0051] S71: The characteristic parameter acquisition module obtains the residual pressure difference after the latest backflush from the data acquisition module. ,in The residual pressure difference after backflushing is expressed in Pa.

[0052] S72: Obtain the latest differential pressure recovery rate from the backflush effect evaluation unit. ,in This refers to the differential pressure recovery rate.

[0053] S73: Obtain the cumulative number of backflush cycles from the PLC controller ,in This refers to the cumulative number of backflush attempts;

[0054] S74: Calculate the average operating temperature from all temperature samples taken during operation. ,in The average operating temperature is expressed in °C.

[0055] S75: The rate of increase in pressure differential is obtained by linear fitting of the pressure differential data over the past 24 hours. ,in This represents the rate of increase in pressure differential, expressed in Pa / h.

[0056] S76: The health assessment module performs normalized scoring calculations for each parameter, and the residual pressure difference score is:

[0057] ,in The residual pressure difference after backflushing is expressed in Pa; 500 is the residual pressure difference limit, also expressed in Pa. It is a function for maximizing the value; It is a minimum value function; Score the residual pressure difference;

[0058] S77: Recovery Rate Score ,in This refers to the differential pressure recovery rate. It is a function for maximizing the value; It is a minimum value function; Score the recovery rate;

[0059] S78: Number of backflushes scored ,in This represents the cumulative number of backflush operations; 10000 is the limit for the number of backflush operations, which is dimensionless. It is a function for maximizing the value; It is a minimum value function; The number of backflips is scored, with points as the unit;

[0060] S79: Temperature Rating ,in The average operating temperature is expressed in °C; 850 is the upper limit of the temperature range, expressed in °C. It is a function for maximizing the value; It is a minimum value function; Temperature is rated in points.

[0061] S710: Rate of Ascent Rating Score ,in The pressure differential rise rate is expressed in Pa / h; 10 represents the rise rate limit, also in Pa / h. It is a function for maximizing the value; It is a minimum value function; The rate of ascent is scored, with points as the unit;

[0062] S711: Uses a weighted summation method to calculate the filter health score. ,in , , , , This is a weighting factor, which is adjusted based on the filter type. Rate the health of the filter cartridge;

[0063] S712: The remaining lifespan calculation module calculates and predicts the remaining lifespan based on the health score. ,in The current health score is given in points; 40 is the scrapping threshold in points; 100 is the initial health score in points; 26280 is the rated lifespan in hours, calculated as 3 years × 365 days / year × 24 hours / day. To predict remaining useful life, the unit is hours; if ,but ;

[0064] S713: If The screen displays a green status indicator to show the filter's health.

[0065] S714: If The screen displays a yellow status and prompts you to replace the filter within one month.

[0066] S715: If When the screen displays a red status and triggers the alarm module to issue an audible and visual alarm, the filter element needs to be replaced immediately.

[0067] Complete the health status assessment and remaining life prediction of filter element based on multi-parameter fusion, and realize the determination of when to replace filter element.

[0068] The beneficial effects achieved by this invention are as follows: This invention realizes efficient purification of high-temperature dust-laden gas and long-term maintenance-free operation of the system. It is comprehensively superior to traditional technologies in terms of filtration efficiency, dust removal effect, filter element life, and operating costs, and has significant technological advancement and economic practicality, specifically manifested in:

[0069] First, this invention designs a radial gradient pore size nano-ceramic filter element that achieves efficient graded filtration and long service life. The filter element consists of an outer coarse filtration layer, a middle medium filtration layer, and an inner fine filtration layer, arranged sequentially from the outside in. The average pore size of the three layers decreases progressively, forming a gradient filtration structure. This allows dust particles of different sizes to be trapped in their respective layers, achieving graded filtration of large, medium, and fine particles. Because large dust particles are pre-trapped in the outer layer, the problem of directly clogging the fine pores of the inner layer is avoided. This fully utilizes the entire thickness of the filter element for dust holding, significantly improving dust holding capacity. The gradient pore size structure also effectively reduces the rate of pressure rise, extends the backflushing interval, and reduces the frequency of backflushing, thereby extending the filter element's service life and reducing system energy consumption.

[0070] Secondly, this invention coats the inner surface of the filter element with a dust-repellent nanocomposite coating, which is chemically bonded to the ceramic substrate. The coating surface has low surface energy groups, significantly reducing the adhesion between dust and the inner surface of the filter element. This greatly reduces the adhesion between the dust cake layer and the filter element surface, causing the dust to exhibit a lotus leaf-like loose adhesion state on the coating surface, with a very small actual contact area with the surface. During backflushing, the dust cake layer is more easily peeled off and removed from the inner surface of the filter element, significantly reducing the residual pressure difference after backflushing and greatly improving the pressure difference recovery rate. The dust-repellent coating also has a self-cleaning effect and excellent high-temperature stability, maintaining its dust-repellent performance for a long time in high-temperature environments, avoiding decomposition and peeling of the coating during use, and ensuring a long-term stable dust removal effect.

[0071] Third, this invention proposes a backflushing triggering mechanism based on differential pressure change rate prediction, realizing a shift from passive response to proactive prevention. The control system continuously collects differential pressure data and calculates the differential pressure change rate. Based on the differential pressure change rate, it predicts the remaining time to reach the differential pressure threshold and determines the clogging stage based on the magnitude of the differential pressure change rate. Backflushing is triggered in advance during the rapid clogging stage, at the appropriate time during the normal clogging stage, and triggered according to the threshold during the slow clogging stage, realizing an adaptive staged triggering strategy. This allows for early intervention in dust removal when the filter element is only slightly clogged, avoiding the problem of deep clogging in traditional fixed differential pressure threshold triggering methods. Because the dust cake layer is thinner and not compacted during early dust removal, the backflushing energy is effectively transferred, resulting in more thorough dust removal and preventing deep irreversible clogging, thereby improving the dust removal effect and extending the filter element's service life.

[0072] Fourth, this invention designs a dual-peak synergistic pulse backflushing system and an adaptive evaluation mechanism for backflushing effect. By configuring a first electromagnetic pulse valve and a second electromagnetic pulse valve with different valve port sizes, a dual-peak synergistic backflushing airflow is formed, consisting of high-pressure impact stripping followed by high-flow-rate removal. The first peak generates a high-pressure pulse with high instantaneous pressure and high velocity, producing a strong impact force that strips the dust cake layer from the filter element surface. The second peak generates a high-flow-rate pulse with a large flow rate and long duration, thoroughly blowing the stripped dust away from the filter element and into the ash hopper. The two pulses work synergistically through precise timing control, significantly improving the thoroughness of dust removal. Simultaneously, the backflushing effect evaluation unit calculates the differential pressure recovery rate in real time and compares it with the target recovery rate. Based on the error, it automatically adjusts the pressure and duration parameters of the next backflushing, achieving adaptive parameter optimization based on the backflushing effect. The closed-loop control mechanism enables the system to automatically adapt to different dust properties and operating conditions, achieving an optimal balance between dust removal effect and energy consumption.

[0073] Fifth, this invention establishes a multi-parameter fusion method for filter element health assessment and lifespan prediction, enabling precise maintenance decisions. The system collects five characteristic parameters: residual pressure difference after backflushing, pressure difference recovery rate, cumulative number of backflushing cycles, average operating temperature, and pressure difference rise rate. It calculates the filter element health score through normalized scoring and weighted summation, and predicts the remaining service life based on a linear lifespan model. This multi-parameter fusion assessment method comprehensively reflects the true health status of the filter element, resulting in more accurate and reliable assessment results. Through a tiered early warning mechanism, corresponding status alerts and maintenance suggestions are provided when the health score drops to different thresholds, allowing maintenance personnel to plan filter element replacement in advance. This avoids resource waste caused by premature replacement or system failures caused by delayed replacement, as in traditional fixed-cycle replacement methods, improving filter element utilization and reducing maintenance costs. Attached Figure Description

[0074] Figure 1 This is a schematic diagram of the composition and structure of a high-temperature resistant, maintenance-free nanofiltration system according to the present invention;

[0075] Figure 2 This is a flowchart of a high-temperature resistant, maintenance-free nanofiltration method according to the present invention. Detailed Implementation

[0076] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0077] Reference Figure 1 The high-temperature resistant, maintenance-free nanofiltration system provided by this invention includes a filter body, a nano-ceramic filter element assembly, an automatic backflushing system, and a control system. The system achieves efficient graded filtration through radial gradient pore size nano-ceramic filter elements, intelligent dust removal through differential pressure change rate prediction and dual-peak synergistic pulse backflushing, and filter element life prediction through multi-parameter health assessment, thereby achieving efficient purification of high-temperature dust-laden gas and long-term maintenance-free operation of the system.

[0078] The dust filter body is the main load-bearing structure of the system, welded from carbon steel or stainless steel plates, with a high-temperature resistant and corrosion-resistant coating on the outer surface. The overall shape of the dust filter body is a vertical box structure, internally divided into three independent but sequentially connected functional areas: an air inlet chamber, a filtration chamber, and an air outlet chamber, by a partition. The air inlet chamber is located on one side or at the bottom of the dust filter body, and a guide plate is installed inside to ensure even airflow distribution and prevent excessive local flow velocity from overloading some filter elements. An air inlet is provided on the side wall of the air inlet chamber, connecting to an air inlet pipe. An air inlet valve is installed on the air inlet pipe to control the entry of dust-laden gas. The air inlet valve is an electric or pneumatic butterfly valve, and its opening and closing are controlled by a PLC controller. The valve is fully open during normal filtration and closed during backflushing. The filtration chamber is located in the central area of ​​the dust filter body and is the main space for filter element installation and filtration. The filtration chamber is separated from the air inlet chamber by a first partition with multiple mounting holes, each corresponding to one filter element. The filter chamber and the exhaust chamber are separated by a second partition, which also has multiple mounting holes corresponding to the filter elements. The two ends of the filter element are sealed to the mounting holes on both partitions using rubber sealing rings or metal gaskets in conjunction with flanges, ensuring that gas can only flow through the interior of the filter element and will not leak from the connection. The exhaust chamber is located on the other side or top of the dust filter body, and its relatively large internal space is used to collect the clean gas filtered by each filter element. An exhaust port is provided on the side wall or top of the exhaust chamber, connecting to an exhaust pipe through which the clean gas is discharged or transported to downstream processes. A dust hopper is located at the bottom of the dust filter body, connected to the bottom of the filter chamber. The hopper has an inverted conical or frustum-shaped structure, with a cone angle typically between 60 and 70 degrees. This angle design allows dust to naturally slide down under gravity and concentrate at the bottom of the hopper. An ash discharge valve is located at the bottom of the ash hopper, which can be a star-shaped unloader, a screw conveyor, or a pneumatic flap valve. The rotary valve uses a motor to drive an impeller to discharge a measured amount of ash while maintaining a sealed system. The screw conveyor uses a motor to drive the screw blades to continuously transport the ash out of the system. The pneumatic flap valve uses a cylinder to open and close the valve plate, discharging ash intermittently. The opening of the ash discharge valve is automatically controlled by a PLC controller based on the set ash discharge cycle or the ash hopper level.

[0079] The nano-ceramic filter element assembly comprises multiple radially gradient pore size nano-ceramic filter elements. The number of filter elements is determined by the system's air volume, typically ranging from 8 to 64. Each filter element has a cylindrical structure, resembling a cylindrical or square tube in shape, with a cylindrical structure being preferred to achieve better strength and uniform airflow distribution. The length of the filter element is generally 1 to 2 meters, the outer diameter is generally 100 to 200 millimeters, and the wall thickness is generally 10 to 20 millimeters. The filter elements are made of nano-alumina, silicon dioxide, or zirconium oxide ceramic materials, prepared using powder metallurgy. The specific preparation process involves layering ceramic powders of different particle sizes into a mold: the outer layer is filled with coarse-grained powder, the middle layer with medium-grained powder, and the inner layer with fine-grained powder. This is followed by dry pressing or isostatic pressing, and finally sintering in a high-temperature furnace at a temperature typically between 1400 and 1600 degrees Celsius for 2 to 4 hours. During the sintering process, powder particles of different sizes are sintered to form porous ceramic structures with different pore sizes. The three layers are sintered into one piece, and metallurgical bonding is formed between the layers. There is no obvious layer interface, which avoids the problem of insufficient interlayer bonding strength of multi-layer composite filter elements.

[0080] The filter element consists of, from the outside in, an outer coarse filtration layer, a middle medium filtration layer, and an inner fine filtration layer. The outer coarse filtration layer is 3 to 5 mm thick, with an average pore size of 5 to 10 micrometers and a porosity of 30% to 40%. It is mainly composed of sintered ceramic particles of 30 to 50 micrometers. This layer has relatively large pores and high porosity, resulting in low airflow resistance and trapping large dust particles larger than 5 micrometers, while allowing small and medium-sized dust particles to pass through to the next layer, preventing large particles from rapidly clogging the filter element surface. The middle medium filtration layer is 4 to 6 mm thick, with an average pore size of 1 to 3 micrometers and a porosity of 25% to 35%. It is mainly composed of sintered ceramic particles of 10 to 20 micrometers. This layer has moderate pore size, trapping medium-sized dust particles of 1 to 5 micrometers, further improving filtration accuracy. The inner fine filter layer is 3 to 5 millimeters thick, with an average pore size of 0.2 to 0.8 micrometers and a porosity of 20% to 30%. It is mainly composed of 2 to 5 micrometer ceramic particles and nano-sized ceramic powder sintered together. This layer has the smallest pore size, trapping fine dust and nanoparticles with a particle size of less than 1 micrometer, achieving ultra-high filtration accuracy. The average pore size and porosity of the three layers decrease sequentially, forming a gradient filtration structure. This gradient structure allows dust of different particle sizes to be trapped in their respective layers, achieving graded filtration and significantly extending the service life of the filter element. Compared with traditional single-pore size filter elements, gradient pore size filter elements avoid rapid clogging caused by all dust accumulating on the surface, making full use of the entire thickness of the filter element for dust holding capacity, which can increase the dust holding capacity by 2 to 3 times.

[0081] The inner surface of the filter element is coated with a dust-repellent nanocomposite coating. This coating is prepared using a sol-gel method or chemical vapor deposition, and its thickness ranges from 1 to 5 micrometers. The coating material is a low surface energy nanocomposite material containing fluorine or silicon, specifically a composite system of perfluoroalkyl silanes, polytetrafluoroethylene nanoparticles, and nano-silica. The coating is chemically bonded to the ceramic substrate surface. Specifically, the ceramic surface is first plasma-activated to generate a large number of hydroxyl groups; then, a coating precursor solution is applied to the surface, where the siloxane groups in the precursor undergo a condensation reaction with the hydroxyl groups on the ceramic surface to form chemical bonds; finally, it is cured by heat treatment to form a stable coating. This coating has extremely low surface energy, generally less than 20 millinewtons per meter, resulting in very low adhesion to dust particles. The coating surface exhibits superhydrophobic or superoleophobic properties, with a water contact angle greater than 150 degrees and an oil contact angle greater than 120 degrees, making it difficult for even oily dust to adhere. The coating also has a self-cleaning effect. Dust particles on the coating surface exhibit a cassie-like state, similar to water droplets on a lotus leaf, with a very small actual contact area with the surface, making them easy to roll off. Through this coating, the adhesion between the dust cake layer and the inner surface of the filter element is significantly reduced, making it easier to peel off during backflushing and significantly improving the backflushing effect. The coating material also needs to have excellent high-temperature stability, remaining undecomposed and unflaking even after long-term use at 850 degrees Celsius, and matching the coefficient of thermal expansion of the ceramic substrate to prevent cracking and peeling of the coating due to thermal stress.

[0082] Each filter element is installed inside the filter chamber. The outer end of the filter element, with its coarse filtration layer, is sealed to the mounting hole on the first partition, while the inner end, with its fine filtration layer, is sealed to the mounting hole on the second partition. During installation, sealing flanges are installed at both ends of the filter element, with rubber sealing rings mounted on them. These flanges are made of high-temperature resistant silicone rubber or fluororubber, with a temperature resistance of 300 to 400 degrees Celsius. The flanges are fixed to the mounting seats on the partitions with bolts. Tightening the bolts causes the sealing rings to deform under pressure, generating a sealing force to ensure airtightness. Support cages can also be installed at both ends of the filter element. These cages are made of stainless steel wire mesh or perforated plates and serve to support the filter element, prevent deformation, and prevent damage during backflushing. During filtration, dust-laden gas enters from the inlet chamber and flows radially through the three filtration layers of the filter element. Dust is trapped on the outer surface of the filter element, while clean gas enters from the inside of the filter element and exits from the outlet chamber. The airflow direction is from the outside to the inside. This flow pattern causes the dust cake to accumulate on the outer surface of the filter element, facilitating backflushing removal.

[0083] The automatic backflush system includes a high-pressure air source, a backflush air path, a first electromagnetic pulse valve, a second electromagnetic pulse valve, a backflush nozzle, and a differential pressure sensor. The high-pressure air source provides the compressed air required for backflush and consists of an air compressor and an air tank. The air compressor is a screw or reciprocating compressor with an output pressure of 0.6 to 0.8 MPa and a flow rate determined according to the system size, typically 1 to 10 cubic meters per minute. The compressed air is dehumidified by a refrigerated dryer or adsorption dryer, reducing the dew point temperature to below -40 degrees Celsius to prevent moisture in the compressed air from condensing and freezing in the pipeline, thus affecting system operation. The dehumidified compressed air enters the air tank, which typically has a volume of 0.5 to 2 cubic meters, used to stabilize the air pressure and store the required amount of compressed air for backflush. A pressure gauge and a safety valve are installed at the outlet of the air tank. The pressure gauge displays the air source pressure, and the safety valve automatically releases pressure to protect the equipment in case of excessive pressure.

[0084] The backflush air circuit consists of pipes, fittings, and valves, connecting the high-pressure air source to the backflush nozzles of each filter element. The main pipe extends from the air tank, using stainless steel or galvanized steel pipe, with a diameter determined by the air volume, typically 50 to 100 mm. A filter is installed on the main pipe to remove solid particles and oil mist from the compressed air, protecting the solenoid valves and nozzles from contamination and clogging. Several branch pipes branch off from the main pipe, each corresponding to the backflush of one filter element or a group of filter elements. A first and second solenoid pulse valve are connected in series on each branch pipe, connected by a short pipe, typically 0.2 to 0.5 meters long. The outlet of the second solenoid pulse valve is connected to the backflush nozzle via the backflush air circuit.

[0085] The first and second electromagnetic pulse valves are the core actuators of the backflush system. While their structures are similar, their valve port sizes differ. The electromagnetic pulse valve employs a diaphragm structure, primarily composed of a valve body, diaphragm, spring, electromagnetic coil, and armature. The valve body is divided into an inlet chamber and an outlet chamber. The inlet chamber is connected to a high-pressure air source, and the outlet chamber is connected to the backflush nozzle. The diaphragm is installed between the inlet and outlet chambers, subjected to compressed air pressure below and spring pressure above. Under normal conditions, the diaphragm is pressed upwards against the valve seat by compressed air, and the valve is closed. When the PLC controller sends a control signal, the electromagnetic coil is energized, generating a magnetic field. This magnetic field attracts the armature upwards, causing it to move. The armature, via a connecting rod, opens the vent hole on the diaphragm, allowing compressed air in the upper chamber to escape rapidly. The pressure above the diaphragm decreases, and the high-pressure gas below overcomes the spring force, pushing the diaphragm downwards, opening the valve. Compressed air is then injected at high speed from the inlet chamber into the outlet chamber, forming a pulsed airflow. When the electromagnetic coil is de-energized, the armature resets under the action of the spring, the vent closes, and the pressure in the chamber above the diaphragm is restored by air replenishment through the throttling orifice. Under the action of pressure and spring force, the diaphragm presses back against the valve seat, and the valve closes. The entire switching process is completed within 0.1 to 0.5 seconds, forming a short and intense pulse of airflow.

[0086] The second electromagnetic pulse valve has a larger orifice size than the first electromagnetic pulse valve. Specifically, the orifice diameter of the first electromagnetic pulse valve is 25 to 40 mm, while the orifice diameter of the second electromagnetic pulse valve is 40 to 65 mm. This difference in orifice size results in different flow and pressure characteristics when the two valves are open. Because of its smaller orifice, the first electromagnetic pulse valve experiences a high airflow velocity and a high peak pressure when open, forming the first peak stripping pulse. The instantaneous pressure of this pulse can reach 0.5 to 0.7 MPa, and the flow velocity can reach 100 to 150 m / s. Its function is to generate a strong instantaneous impact force, causing the dust cake layer to peel off from the filter element surface. Because of its larger orifice, the second electromagnetic pulse valve experiences a large flow rate and a relatively lower peak pressure when open, forming the second peak purging pulse. The pressure of this pulse is 0.4 to 0.6 MPa, and the flow rate is 1.5 to 2 times that of the first peak. Its duration is longer, and its function is to completely blow the stripped dust away from the filter element and into the dust hopper. The combination of the two pulses forms a dual-peak synergistic backflushing airflow that first performs high-pressure impact stripping and then high-flow-rate cleaning, resulting in a better dust removal effect than single-pulse backflushing.

[0087] The backflush nozzle is connected to the outlet of the second electromagnetic pulse valve. The nozzle is made of stainless steel, with a diameter matching the outlet of the electromagnetic valve, typically 40 to 65 mm. The nozzle extends into the filter element, with its outlet facing the inner surface of the filter element. The distance between the outlet and the inner surface of the filter element is 20 to 50 mm. The nozzle outlet can be an open straight pipe or a distributor with multiple nozzles. The distributor has multiple nozzles evenly spaced along the length of the nozzle, with a diameter of 5 to 10 mm, ensuring uniform distribution of the backflush airflow along the length of the filter element and improving cleaning uniformity. The nozzle is fixed to the end cap or support frame of the filter element and is coaxially mounted with the filter element to ensure symmetrical airflow distribution. During backflush, the pulsed airflow is ejected at high speed from the nozzle outlet, impacting the inner surface of the filter element and generating a reverse airflow that penetrates the filter element wall, blowing away the dust cake layer on the outer surface from the inside.

[0088] A differential pressure sensor is used to monitor the pressure difference across the filter element in real time. The sensor employs a differential pressure transmitter with two pressure measurement ports, connected to the outer and inner sides of the filter element via pressure taps. The outer pressure tap is located inside the filter chamber near the outer surface of the filter element, while the inner pressure tap is located inside the outlet chamber near the inner surface of the filter element, or directly connected to the backflush nozzle. The pressure taps are made of stainless steel or high-temperature resistant flexible tubing, typically with a diameter of 6 to 10 mm. The differential pressure sensor internally uses a silicon piezoresistive or capacitive pressure sensing element to convert the pressure difference between the two sides into a 4 to 20 mA current signal or a 0 to 10 V voltage signal output. The sensor's measurement range is 0 to 5000 Pascals, with an accuracy of ±1% of full scale and a response time of less than 1 second. The sensor installation location should avoid direct airflow and dust blockage. A purging device can be installed on the pressure taps to periodically purge accumulated dust from the taps with compressed air, ensuring measurement accuracy. The output signal of the differential pressure sensor is connected to the data acquisition module of the control system, transmitting differential pressure data in real time for use by the control algorithm.

[0089] The control system is the central control hub of the entire dust filtration system, including a PLC controller, touch screen, alarm module, data acquisition module, differential pressure change rate calculation unit, backflushing trigger judgment unit, backflushing timing control unit, backflushing effect evaluation unit, and filter element life prediction unit. The PLC controller, a programmable logic controller, adopts the Siemens S7 series and possesses powerful logic operation, data processing, analog signal processing, and communication functions, ensuring reliable operation in harsh environments such as high temperature, vibration, and electromagnetic interference. The PLC controller's CPU module executes the control program and coordinates the work of various functional units; the digital input module receives switching signals from sensors such as differential pressure sensors, temperature sensors, and limit switches; the digital output module controls the switching actions of actuators such as electromagnetic pulse valves, inlet valves, and ash discharge valves; the analog input module receives analog signals from differential pressure sensors and temperature sensors; and the communication module communicates with the touch screen, host computer, and data acquisition system via protocols such as Ethernet, Modbus, and PROFIBUS.

[0090] The touchscreen connects to the PLC controller via Ethernet or serial port for setting operating parameters and displaying real-time data. The touchscreen uses an industrial-grade human-machine interface, typically 7 to 15 inches in size with a resolution of 800 x 600 to 1024 x 768 pixels. The touch method is resistive or capacitive, and it has an IP65 dustproof and waterproof rating. The main interface displays the system's operating status, including real-time data such as the current differential pressure value, differential pressure curve, working status of each filter element, backflushing frequency, and filter element health score, displayed intuitively in various formats including numbers, curves, bar charts, and color blocks. The parameter setting interface is used to input operating parameters such as differential pressure threshold, backflushing interval time, backflushing pressure, and target recovery rate. Operators input values ​​or select options via touch operation. The alarm interface displays current alarm information, including alarm time, alarm content, and alarm level, facilitating quick problem location for operators. The historical data interface allows querying historical operating data and curves, supports data export, and facilitates analysis and archiving.

[0091] The alarm module connects to the PLC controller for abnormal status alarms. The alarm module includes an audible and visual alarm, a buzzer, and indicator lights. The audible and visual alarm is installed in a prominent location on the equipment; when an abnormality occurs, it emits a buzzing sound and flashes a red light to alert operators. The buzzer volume is adjustable, with a sound frequency of 2 to 4 kHz, and the flashing frequency is 1 to 2 Hz. The indicator lights use LEDs; different colors represent different states: green for normal operation, yellow for a warning state, red for a fault alarm, and blue for equipment shutdown. The alarm module can also be connected to the factory's DCS (Distributed Control System) or SCADA (Supervisory Control and Data Acquisition) system for remote alarm and centralized monitoring. Alarm conditions include various abnormal situations such as excessive differential pressure, low filter health, backflushing system malfunction, insufficient air supply pressure, and ash discharge valve malfunction.

[0092] The ash discharge valve is controlled by a PLC controller and opens periodically based on the set ash discharge cycle or ash hopper level signal. The ash discharge cycle is generally set to 2 to 8 hours, depending on the amount of dust. A level switch or level gauge can be installed in the ash hopper; it automatically triggers ash discharge when the accumulated ash reaches a set height. Each opening of the ash discharge valve lasts 1 to 5 minutes, automatically closing after the accumulated ash is discharged. During the ash discharge process, the system continues to operate the filter, without affecting production. The discharged dust enters a dust collection device, such as a ton bag, silo, or pneumatic conveying system, for unified treatment or recycling.

[0093] The data acquisition module connects to the differential pressure sensor signal for continuous acquisition of differential pressure data. The data acquisition module, essentially the PLC's analog input module, has multiple analog input channels, each corresponding to one sensor. The module converts the 4-20 mA current signal or 0-10 V voltage signal output from the sensor into a digital signal via an analog-to-digital converter (ADC). The conversion accuracy is 12-bit to 16-bit, and the conversion speed is 100-1000 times per second. The converted digital signal is stored in the PLC's data register for use by various functional units. The data acquisition module also features signal conditioning functions, including signal amplification, filtering, linearization, zero-point calibration, and range calibration, ensuring the accuracy of the acquired data. The data acquisition cycle is set to 1 second, meaning the differential pressure value is acquired once per second. This cycle effectively captures the trend of differential pressure changes without incurring excessive data processing overhead.

[0094] The differential pressure change rate calculation unit is connected to the data acquisition module. It reads differential pressure data from the data register and performs moving average filtering and differential algorithms to calculate the differential pressure change rate. This unit is implemented as a function block in the PLC's CPU module. The function block receives real-time differential pressure data as input and outputs the moving average and differential pressure change rate. Internally, the function block maintains a data buffer of length 5, storing the differential pressure values ​​of the last 5 samples. Each time new data arrives, the oldest data is removed from the buffer, and the new data enters the buffer. Then, the arithmetic mean of the 5 data in the buffer is calculated as the moving average of the differential pressure. Simultaneously, another buffer is maintained to store the moving average of the differential pressure for differential calculation. The differential pressure change rate is calculated using a backward difference method with a 5-second time interval. That is, the moving average at the current moment is subtracted from the moving average 5 seconds ago, and the result is divided by 5 seconds to obtain the change rate. This algorithm is simple to calculate, has good real-time performance, and effectively reflects the trend of differential pressure change. The calculated differential pressure change rate is stored in the PLC's data register for use by the backflush trigger judgment unit.

[0095] The backflush triggering judgment unit is connected to the differential pressure change rate calculation unit. It predicts the remaining time to reach the differential pressure threshold based on the differential pressure change rate and determines the timing for backflush triggering. This unit is also implemented as a function block in the PLC. The function block receives the current differential pressure value and differential pressure change rate as input and outputs a backflush trigger signal. Internally, the function block first calculates the arithmetic mean of the last 10 differential pressure change rates using a sliding window algorithm. It maintains a data buffer of length 10 to store the last 10 differential pressure change rate values ​​and calculates the average value of the data in the buffer as the average differential pressure change rate. Then, it calculates the predicted remaining time based on a linear prediction model, i.e., the difference between the differential pressure threshold and the current differential pressure, divided by the average differential pressure change rate. Next, it judges the relationship between the predicted remaining time and the average differential pressure change rate and the set threshold, determining the advance triggering time based on different blockage stages. When the triggering conditions are met, the function block outputs a backflush trigger signal, which is either a pulse signal or a set signal, and sends it to the backflush timing control unit. In addition, the function block records the system running time. When the running time reaches the upper limit of the backflush interval, a forced backflush trigger signal is output regardless of the differential pressure. Through the intelligent judgment of this unit, adaptive backflush control based on differential pressure change rate prediction is realized. Compared with the traditional fixed differential pressure threshold triggering method, it intervenes in dust removal in advance, avoids deep blockage, and significantly improves the system's operational stability.

[0096] The backflush timing control unit is connected to the PLC controller and electrically connected to the first and second electromagnetic pulse valves respectively, used to independently control the opening time and duration of the two electromagnetic pulse valves. This unit is implemented in the PLC in the form of a sequential function chart or state machine, including multiple sequential steps and transition conditions. When this unit receives a backflush trigger signal, it starts the backflush sequence control. First, the PLC outputs a control signal to close the intake valve, waits for the valve to close completely, and delays for 2 to 5 seconds to ensure airflow stability before proceeding to the next step. Second, the PLC sends an opening signal to the first electromagnetic pulse valve, which opens for a duration controlled by a timer set to 0.1 to 0.2 seconds. After the timer expires, the PLC sends a closing signal, and the first electromagnetic pulse valve closes. Third, a delay of 0.05 to 0.15 seconds, controlled by another timer, occurs. Fourth, the PLC sends an opening signal to the second electromagnetic pulse valve, which opens for a duration set to 0.3 to 0.5 seconds. After the timer expires, the PLC sends a closing signal, and the second electromagnetic pulse valve closes. Fifth, delay for 5 to 10 seconds to allow dust to settle and airflow to stabilize. Sixth, the PLC outputs a control signal to open the intake valve, resuming filtration operation. The backflush timing control unit precisely controls the opening time and duration of the two electromagnetic pulse valves to achieve dual-peak coordinated backflush. This unit also receives parameter adjustment commands from the backflush effect evaluation unit, and adaptively adjusts the first peak pressure, second peak pressure, and second peak duration according to the commands to achieve parameter optimization. Pressure adjustment is achieved by controlling the air source pressure regulating valve, which is an electro-proportional pressure regulating valve. The PLC outputs an analog signal to control the valve opening, thereby precisely regulating the output pressure.

[0097] The backflush effect evaluation unit is connected to the data acquisition module and the backflush timing control unit. It calculates the differential pressure recovery rate before and after backflush and sends parameter adjustment commands to the backflush timing control unit based on the evaluation results. This unit is implemented as a function block in the PLC. Before backflush is triggered, the function block reads the current differential pressure value from the data register and records it as the pre-backflush differential pressure. After backflush is completed and operation stabilizes, it reads the current differential pressure value and records it as the post-backflush differential pressure. Then, it calculates the differential pressure recovery rate according to the formula. The function block compares the calculated recovery rate with the target recovery rate and calculates the error value. Then, based on the error value, it uses a proportional adjustment algorithm to calculate the backflush pressure adjustment amount. The proportional coefficient is set to 0.1. This coefficient is selected based on the system response characteristics and stability requirements; an excessively large coefficient will cause oscillation, while an excessively small coefficient will result in a slow response. The calculated pressure adjustment amount is used to correct the first and second peak pressures of the next backflush. Simultaneously, based on the error value, it calculates the adjustment amount for the duration of the second peak. When the recovery rate is lower than the target value, the duration is extended; when the recovery rate is higher than the target value, the duration is shortened. The adjustment step is 0.001 seconds multiplied by the error percentage. The function block sends the adjusted parameters to the backflushing timing control unit to update the control parameters for the next backflushing. This unit also records the recovery rate data for each backflushing operation, storing it in a historical database. Historical curves can be queried via a touchscreen for analyzing system performance and optimizing parameters. Through real-time evaluation and adaptive adjustment by this unit, the system dynamically optimizes parameters based on the actual backflushing effect, achieving an optimal balance between cleaning efficiency and energy consumption, while adapting to changes in different operating conditions and dust properties.

[0098] The filter cartridge life prediction unit is connected to the data acquisition module to collect multiple characteristic parameters, calculate the filter cartridge health score, and predict the remaining service life. This unit includes three sub-modules: a characteristic parameter acquisition module, a health score module, and a remaining service life calculation module. The characteristic parameter acquisition module is connected to the data acquisition module and a temperature sensor signal to collect five characteristic parameters: residual pressure difference after backflushing, pressure difference recovery rate, cumulative backflushing count, average operating temperature, and pressure difference rise rate. The temperature sensor, using a thermocouple or resistance temperature detector (RTD), is installed inside the intake chamber to measure the intake air temperature. The temperature signal is input to the PLC via an analog input module. The characteristic parameter acquisition module reads the parameter values ​​from the corresponding data sources. The residual pressure difference after backflushing is calculated by subtracting the initial pressure difference from the backflushing pressure difference; the pressure difference recovery rate is obtained from the backflushing effect evaluation unit; the cumulative backflushing count is accumulated and recorded by an internal counter in the PLC, incrementing by 1 each time backflushing is triggered; the average operating temperature is obtained by calculating the arithmetic mean of all temperature samples during operation; and the pressure difference rise rate is obtained by performing a least-squares linear fitting on the pressure difference data after backflushing for the most recent 24 hours to obtain the slope of the fitted line.

[0099] The health rating module is connected to the feature parameter acquisition module. It performs normalized scoring calculations on each feature parameter and calculates the filter cartridge health rating through weighted summation. This module establishes a scoring function for each feature parameter, mapping the parameter value to a range of 0 to 100 points. The residual pressure difference score uses a linear decreasing function: 100 points for a residual pressure difference of 0, 0 points for a residual pressure difference of 500 Pascals, and 0 points for any value exceeding 500 Pascals. The pressure difference recovery rate score directly maps the recovery rate percentage to a score. The backflush frequency score uses a linear decreasing function: 100 points for 0 backflush frequencies and 0 points for 10,000 backflush frequencies. The temperature score uses a linear decreasing function: 100 points for a temperature of 20 degrees Celsius and 0 points for a temperature of 850 degrees Celsius. The pressure difference rise rate score uses a linear decreasing function: 100 points for a rise rate of 0, and 0 points for a rise rate of 10 Pascals per hour. After each score is calculated, a weighted summation method is used to calculate the overall health score. The weighting coefficients are 0.3, 0.3, 0.2, 0.1, and 0.1, respectively. These weighting coefficients are set based on the importance of each parameter to the filter cartridge's lifespan. Residual pressure difference and recovery rate are the most important and therefore have the highest weights, followed by the number of backflushing cycles, while temperature and rise rate have lower weights. The weighted summation formula is: Health score = 0.3 multiplied by residual pressure difference score + 0.3 multiplied by recovery rate score + 0.2 multiplied by backflushing cycles score + 0.1 multiplied by temperature score + 0.1 multiplied by rise rate score. The health score ranges from 0 to 100, where 100 indicates the filter cartridge is in brand new condition, and 0 indicates the filter cartridge is completely failed.

[0100] The remaining lifespan calculation module is connected to the health rating module, used to calculate and predict the remaining lifespan based on the health rating and provide early warnings. This module uses a linear lifespan model, assuming the health rating linearly decreases from an initial 100 points to a scrap threshold of 40 points, and linearly extrapolates the remaining lifespan based on the current health rating's position within this range. The calculation formula is: remaining lifespan = current health rating - 40 divided by 100 - 40 multiplied by the rated lifespan of 26280 hours. 26280 hours corresponds to 3 years of continuous operation, which is the design life of the nano-ceramic filter element. When the health rating is less than or equal to 40 points, the remaining lifespan is 0, and the filter element reaches the scrap state. This module provides tiered warnings based on different ranges of the filter's health score. When the score is 70 or higher, a green status is displayed on the touchscreen, indicating that the filter is healthy. When the score is between 55 and 70, a yellow status is displayed on the touchscreen, and a pop-up window prompts that the filter should be replaced within one month. This warning timing provides sufficient lead time, allowing maintenance personnel ample time to prepare spare parts and plan downtime maintenance. When the score is between 40 and 55, a red status is displayed on the touchscreen, triggering an audible and visual alarm, indicating that the filter needs to be replaced immediately. At this point, the filter's performance has severely deteriorated, and failure to replace it in time may result in substandard filtration or filter damage. When the score is below 40, the system automatically shuts down for protection, preventing the leakage of unfiltered dust-laden gas due to filter damage. Through this unit's multi-parameter fusion evaluation and tiered warnings, intelligent management of the filter's entire life cycle is achieved, avoiding the waste of premature replacement or the failure of late replacement caused by traditional fixed-cycle replacement. This improves filter utilization and reduces operating costs.

[0101] The high-temperature resistant, maintenance-free nanofiltration method designed in this invention, such as... Figure 2 As shown, a high-temperature resistant, maintenance-free nanofiltration system is used to achieve efficient purification of high-temperature dust-laden gas and long-term maintenance-free operation of the system. The specific process is as follows:

[0102] S1: System initialization and parameter setting;

[0103] The operating parameters are set via the touchscreen, and the initial differential pressure of the clean filter element is measured; this includes the following sub-steps:

[0104] S11: Input differential pressure threshold via touchscreen ,in The pressure difference threshold is measured in Pa, and its preferred setting range is 500 Pa to 800 Pa. This threshold is used to determine the degree of filter clogging.

[0105] S12: Input the threshold for the rate of change of rapid choking pressure differential. ,in The threshold value for the rate of change of differential pressure during rapid blockage is expressed in Pa / s, and its preferred setting is 1.5 Pa / s. This threshold is used to identify the rapid blockage stage.

[0106] S13: Input the threshold for the rate of change of slow blockage pressure differential ,in The threshold value for the rate of change of differential pressure during slow blockage is expressed in Pa / s, and its preferred setting is 0.5 Pa / s. This threshold is used to identify the slow blockage stage.

[0107] S14: Input the upper limit of the backflush interval time ,in The upper limit of the backflush interval time is expressed in minutes, and its preferred setting range is 10 minutes to 60 minutes, serving as a time limit for forced backflush.

[0108] S15: Start the system and introduce clean gas at the rated flow rate in clean mode. The differential pressure sensor measures the pressure difference across the filter element at this time, and the PLC controller records this pressure difference as the initial pressure difference. ,in The initial differential pressure is expressed in Pa. This step completes the system initialization and baseline value establishment, ensuring the accuracy of subsequent differential pressure monitoring and backflush control. At the same time, parameter settings allow the method to adapt to different working conditions, improving the system's flexibility and adjustability.

[0109] S2: Filter cycle starts;

[0110] When the filtration cycle is started, dust-laden gas enters the filtration chamber from the inlet chamber and passes through the three filter layers of the filter element for graded interception. Clean gas is discharged from the outlet chamber. During the filtration process, the dust-laden gas first comes into contact with the outer coarse filter layer of the filter element. This layer has a larger average pore size and is used to intercept large dust particles. Then the gas enters the middle medium filter layer to intercept medium-sized dust particles. Finally, it passes through the inner fine filter layer to intercept fine dust particles, achieving gradient filtration. This graded interception method avoids dust directly clogging the fine pores of the inner layer, extending the service life of the filter element. At the same time, the dust-repellent nanocomposite coating on the inner surface of the filter element reduces dust adhesion through low surface energy groups, making it easier for the dust cake to peel off during backflushing.

[0111] S3: Differential pressure monitoring and rate of change calculation;

[0112] The differential pressure sensor continuously measures the pressure difference across the filter element. The data acquisition module collects the differential pressure data and transmits it to the differential pressure change rate calculation unit for calculation. Specifically, this includes the following sub-steps:

[0113] S31: The differential pressure sensor continuously measures the pressure difference between the outer and inner sides of the filter element with a sampling period of 1 second to obtain the real-time differential pressure value. ,in This represents the pressure difference at the current moment, in Pa.

[0114] S32: The data acquisition module transmits the differential pressure data to the differential pressure change rate calculation unit.

[0115] S33: The pressure difference change rate calculation unit uses moving average filtering and differential algorithm to calculate the pressure difference change rate. First, it calculates the moving average of the pressure difference at the current moment. ,in This represents the pressure difference at the current moment, in Pa. This is the pressure difference value from the previous second, in Pa. This is the pressure difference value for the first two seconds, in Pa. This is the pressure difference value for the first three seconds, in Pa. The pressure difference is the value over the first four seconds, in Pa; 5 is the size of the moving average window. The moving average of the differential pressure at the current moment, in Pa; then calculate the rate of change of differential pressure. ,in This is the moving average of the differential pressure at the current moment, in Pa. The moving average of the differential pressure 5 seconds ago, in Pa; 5 represents the time interval, in seconds. The pressure difference change rate is expressed in Pa / s. By using moving average filtering and differential calculation, the method monitors the pressure difference change trend in real time, reduces noise interference, and improves prediction accuracy, thereby providing a reliable data basis for backflush triggering.

[0116] S4: Determining when the backflush triggers;

[0117] The backflush triggering judgment unit predicts the remaining time to reach the differential pressure threshold based on the differential pressure change rate, and determines the timing of backflush triggering based on the magnitude of the differential pressure change rate to indicate the blockage stage; specifically, it includes the following sub-steps:

[0118] S41: The backflush trigger judgment unit obtains the current differential pressure change rate from the differential pressure change rate calculation unit. and current pressure difference ,in This represents the current rate of change of differential pressure, in Pa / s. This represents the current pressure difference, expressed in Pa.

[0119] S42: Calculate the arithmetic mean of the rate of change of pressure difference for the most recent 10 samples. ,in This represents the average rate of change of pressure difference, in Pa / s.

[0120] S43: Calculate the remaining forecast time based on the linear forecasting model. ,in This is the differential pressure threshold, in Pa. This is the current pressure difference, in Pa. This represents the average rate of change of pressure difference, in Pa / s. To predict the remaining time, the unit is seconds; if If the value is Pa / s, a backflush is triggered directly, avoiding prediction failure due to an excessively small rate of change.

[0121] S44: Determine the current rate of change of differential pressure relative to the threshold. , The relationship, among which The threshold for the rate of change of differential pressure during rapid blockage, in Pa / s; The threshold for the rate of change of differential pressure during slow blockage, expressed in Pa / s.

[0122] S45: If It is determined to be in the rapid congestion phase, when achieve It issues an early backflush trigger signal.

[0123] S46: If This is determined to be a normal congestion phase. achieve A backflush trigger signal is issued at the appropriate time.

[0124] S47: If It is determined to be in the slow congestion stage. achieve A backflush trigger signal is issued at the appropriate time.

[0125] S48: Or when the runtime reaches Regardless of the pressure difference, a backflush trigger signal is issued, in which... This is the upper limit of the backflushing interval time, in minutes. Through this step, the method dynamically predicts the clogging trend based on the differential pressure change rate and adopts corresponding triggering strategies at different clogging stages. This enables early dust removal when the filter element is slightly clogged, avoiding deep clogging that reduces the backflushing effect. At the same time, the upper limit of the time ensures regular system maintenance and improves operational reliability.

[0126] S5: Backflush process control;

[0127] After receiving the backflushing trigger signal, the backflushing timing control unit controls the backflushing process. First, it closes the air inlet valve, and then controls the first and second electromagnetic pulse valves to open and close sequentially according to the set timing to form a dual-peak synergistic backflushing airflow. After the backflushing is completed, the air inlet valve is reopened. During the backflushing process, the first electromagnetic pulse valve opens first, generating a high-pressure pulse airflow as the first peak stripping pulse, which is used to impact the inner surface of the filter element to strip the dust cake layer. Then, the second electromagnetic pulse valve opens, generating a large-flow pulse airflow as the second peak cleaning pulse, which is used to blow the stripped dust into the ash hopper. The dual-peak synergistic airflow design improves the cleaning efficiency and thoroughness, while the timing control avoids airflow interference and ensures stable backflushing effect.

[0128] S6: Backflush effect evaluation and parameter adjustment;

[0129] The backflush effect evaluation unit collects the pressure difference before and after backflush, calculates the pressure difference recovery rate, and adjusts the pressure and duration parameters for the next backflush based on the magnitude of the pressure difference recovery rate; specifically, it includes the following sub-steps:

[0130] S61: Before step S5 begins, the backflush effect evaluation unit obtains the current differential pressure value from the data acquisition module and records it as the differential pressure before backflush. ,in The pressure difference before backflushing is expressed in Pa.

[0131] S62: After step S5 ends and the filtration operation stabilizes, obtain the current differential pressure value from the data acquisition module and record it as the differential pressure after backflushing. ,in This represents the pressure difference after backflushing, expressed in Pa.

[0132] S63: Calculate the differential pressure recovery rate ,in The pressure difference before backflushing is expressed in Pa. This represents the pressure difference after backflushing, in Pa. This is the initial pressure difference, in Pa. This represents the differential pressure recovery rate, expressed as a percentage (%).

[0133] S64: Set target recovery rate Calculation error ,in The target recovery rate is expressed in % (%). The error is expressed as a percentage.

[0134] S65: Adjust the backflush parameters based on the error, and calculate the backflush pressure adjustment amount. ,in This is the proportionality constant, set to 0.1, and is dimensionless. This is the backflush pressure adjustment amount, in %; then adjust the first peak pressure of the next backflush to... The second peak pressure is ,in The pressure at the first peak is measured in Pa. The pressure of the second peak is expressed in Pa; the duration of the second peak is also adjusted. ,in The duration of the second peak is expressed in seconds. The error is expressed in %; through this step, the method optimizes parameters in real time based on the backflushing effect, achieving the optimal balance between dust removal effect and energy consumption, while adapting to different dust properties and operating conditions, thus improving the long-term stability of the system.

[0135] S7: Filter life prediction and early warning;

[0136] The filter life prediction unit collects multiple feature parameters, calculates the filter health score using a weighted scoring method, and predicts the remaining service life of the filter based on the health score, issuing an early warning. Specifically, it includes the following sub-steps:

[0137] S71: The characteristic parameter acquisition module obtains the residual pressure difference after the latest backflush from the data acquisition module. ,in The residual pressure difference after backflushing is expressed in Pa.

[0138] S72: Obtain the latest differential pressure recovery rate from the backflush effect evaluation unit. ,in This represents the differential pressure recovery rate.

[0139] S73: Obtain the cumulative number of backflush cycles from the PLC controller ,in This refers to the cumulative number of times the product has been backflowed.

[0140] S74: Calculate the average operating temperature from all temperature samples taken during operation. ,in The average operating temperature is expressed in °C.

[0141] S75: The rate of increase in pressure differential is obtained by linear fitting of the pressure differential data over the past 24 hours. ,in This represents the rate of increase in pressure differential, expressed in Pa / h.

[0142] S76: The health assessment module performs normalized scoring calculations for each parameter, with the residual pressure differential score being... ,in The residual pressure difference after backflushing is expressed in Pa; 500 is the residual pressure difference limit, also expressed in Pa. It is a function for maximizing the value; It is a minimum value function; The residual pressure differential is scored.

[0143] S77: Recovery Rate Score ,in This refers to the differential pressure recovery rate. It is a function for maximizing the value; It is a minimum value function; Score the recovery rate.

[0144] S78: Number of backflushes scored ,in This represents the cumulative number of backflush operations; 10000 is the limit for the number of backflush operations, which is dimensionless. It is a function for maximizing the value; It is a minimum value function; The number of times a counter-blow is performed is scored, with the unit being points.

[0145] S79: Temperature Rating ,in The average operating temperature is expressed in °C; 850 is the upper limit of the temperature range, expressed in °C. It is a function for maximizing the value; It is a minimum value function; Temperature is rated in points.

[0146] S710: Rate of Ascent Rating Score ,in The pressure differential rise rate is expressed in Pa / h; 10 represents the rise rate limit, also in Pa / h. It is a function for maximizing the value; It is a minimum value function; The rate of increase is scored, in points.

[0147] S711: Uses a weighted summation method to calculate the filter health score. ,in , , , , The weighting coefficient is preferably set to [value]. , , , , Furthermore, the weighting coefficient can be adjusted based on the filter type; Rate the health of the filter element.

[0148] S712: The remaining lifespan calculation module calculates and predicts the remaining lifespan based on the health score. ,in The current health score is given in points; 40 is the scrapping threshold in points; 100 is the initial health score in points; 26280 is the rated lifespan in hours, calculated as 3 years × 365 days / year × 24 hours / day. To predict remaining useful life, the unit is hours; if ,but .

[0149] S713: If The screen displays a green status indicator on the touchscreen, indicating that the filter is healthy.

[0150] S714: If The screen displays a yellow status and prompts you to schedule a filter replacement within one month.

[0151] S715: If The system displays a red status on the touchscreen and triggers an alarm module to issue an audible and visual alarm indicating that the filter element needs to be replaced immediately. Through this step, the method achieves filter element health status assessment and remaining life prediction based on multi-parameter fusion, accurately determines the timing of filter element replacement, avoids resource waste caused by premature replacement or system failure caused by delayed replacement, and improves maintenance efficiency through graded early warning.

[0152] S8: Loop operation;

[0153] Return to step S2 to continue the filtration cycle until the filter health score drops to the scrap threshold, prompting for filter replacement. By cyclically executing the filtration and backflushing process, the method ensures the continuous operation and long-term maintenance-free performance of the system. Through differential pressure change rate prediction, dual-peak synergistic backflushing, adaptive adjustment of backflushing effect, and multi-parameter life prediction, it achieves efficient purification of high-temperature dusty gas.

[0154] Example 1 provides a specific implementation case of a high-temperature resistant, maintenance-free nanofiltration system and method for blast furnace gas purification in a steel plant. The system is installed in the blast furnace gas purification section of a large steel plant to treat gases at a temperature of 650℃ and a dust concentration of 80g / m³. 3 Blast furnace gas, with a processing volume of 50,000 m³ / h. 3The system employs 32 radially gradient pore size nano-ceramic filter elements, each 1.5m long, 150mm in outer diameter, and 15mm thick. From the outside in, each filter element comprises an outer coarse filtration layer (4mm thick, 8μm average pore size, 35% porosity), a middle medium filtration layer (5mm thick, 2μm average pore size, 30% porosity), and an inner fine filtration layer (4mm thick, 0.5μm average pore size, 25% porosity), all three layers integrally sintered. The inner surface of the filter element is coated with a 3μm thick perfluoroalkyl silane dust-repellent nanocomposite coating with a surface energy of 18mN / m. The automatic backflushing system is equipped with a 0.7MPa high-pressure air source, a first electromagnetic pulse valve with a 32mm orifice diameter, and a second electromagnetic pulse valve with a 55mm orifice diameter. The control system uses a Siemens S7-1200 PLC equipped with a 10-inch touchscreen. The implementation steps are as follows:

[0155] S1: System Initialization and Parameter Setting. Operators set operating parameters via the touchscreen, which includes the following sub-steps.

[0156] S11: Input differential pressure threshold Pa, this threshold is determined based on the dust characteristics of blast furnace gas and the system design pressure loss.

[0157] S12: Input the threshold for the rate of change of rapid choking pressure differential. Pa / s is used to identify rapid congestion phases.

[0158] S13: Input the threshold for the rate of change of slow blockage pressure differential Pa / s is used to identify slow congestion phases.

[0159] S14: Input the upper limit of the backflush interval time min, ensure the system is maintained regularly.

[0160] S15: After starting the system, introduce a rated flow rate of 50,000 m³ / h in the clean state. 3 With a clean air supply of / h, the differential pressure sensor measures a pressure difference of 120Pa across the filter element, and the PLC controller records this value as the initial differential pressure. Pa, system initialization complete.

[0161] S2: Filtration cycle starts. Dust-laden blast furnace gas enters the filtration chamber from the inlet chamber, flowing radially through the outer coarse filter layer, the middle medium filter layer, and the inner fine filter layer of the filter element. The outer coarse filter layer traps large dust particles larger than 5μm, the middle medium filter layer traps medium dust particles of 1 to 5μm, and the inner fine filter layer traps fine dust particles smaller than 1μm, achieving graded trapping. The purified gas is discharged from the outlet chamber, with an outlet dust concentration of less than 10mg / m³. 3 This meets the requirements of subsequent processes.

[0162] S3: Differential pressure monitoring and rate of change calculation. During system operation, the differential pressure sensor continuously measures the differential pressure with a period of 1 second.

[0163] S31: The current pressure difference is measured at the 1800th second of operation. Pa.

[0164] S32: The data acquisition module transmits the differential pressure data to the differential pressure change rate calculation unit.

[0165] S33: Pressure differential change rate calculation unit calculates the moving average pressure differential. Pa, then calculate the rate of change of pressure difference. Pa / s.

[0166] S4: Backflush trigger timing judgment. The backflush trigger judgment unit receives the current differential pressure and differential pressure change rate, and performs the following judgment.

[0167] S41: Obtain the current rate of change of differential pressure Pa / s and current pressure difference Pa.

[0168] S42: Calculate the average of the most recent 10 differential pressure change rates. Pa / s.

[0169] S43: Calculate the remaining forecast time based on the linear forecasting model. s.

[0170] S44: Determine the relationship between the rate of change of differential pressure and the threshold. Pa / s Pa / s.

[0171] S45: Determined to be in a rapid congestion phase, when A pre-flush trigger signal is issued when 60 seconds have elapsed, that is, the flush is triggered at 1805 seconds.

[0172] S5: Backflush process control. After receiving the trigger signal, the backflush timing control unit controls the backflush process according to the following timing sequence.

[0173] S21: At time 1805s, the PLC outputs a signal to close the intake valve and waits for 3s for the airflow to stabilize.

[0174] S22: At 1808s, the PLC sends an opening signal to the first electromagnetic pulse valve. The valve remains open for 0.15s, generating the first peak stripping pulse. The instantaneous pressure reaches 0.68MPa and the flow velocity reaches 135m / s, forcefully impacting the inner surface of the filter element and causing the dust cake layer to peel off. The first electromagnetic pulse valve closes at 1808.15s.

[0175] S23: After a delay of 0.1s, at 1808.25s, the PLC sends an opening signal to the second electromagnetic pulse valve. The valve remains open for 0.4s, generating a second peak purging pulse with a pressure of 0.55MPa and a flow rate 1.8 times that of the first peak, thoroughly blowing the stripped dust into the ash hopper. The second electromagnetic pulse valve closes at 1808.65s.

[0176] S24: After an 8-second delay to allow dust to settle, the PLC opens the intake valve at 1816.65 seconds to resume filtration operation. The entire backflushing process takes 11.65 seconds.

[0177] S6: Backflush effect evaluation and parameter adjustment. The backflush effect evaluation unit collects data and calculates evaluation indicators.

[0178] S61: Pressure differential before backflushing Pa (actual pressure difference when backflush is triggered).

[0179] S62: After backflushing and returning to stable operation for 10 seconds, the pressure difference after backflushing was measured. Pa.

[0180] S63: Calculate the differential pressure recovery rate .

[0181] S64: Target Recovery Rate Calculation error .

[0182] S65: Calculate the pressure adjustment amount because the recovery rate is higher than the target value. The next backflushing will lower the first peak pressure to 0.68. (1-0.82%)=0.674MPa, the second peak pressure drops to 0.55 MPa. (1-0.82%)=0.545MPa. Simultaneously, shorten the duration of the second peak to 0.4-0.001 MPa. 8.2 = 0.392s.

[0183] S7: Filter life prediction and early warning. After 1000 hours of system operation, the filter life prediction unit performs a health assessment.

[0184] S71: Residual pressure difference after the latest backflushing Pa.

[0185] S72: Latest differential pressure recovery rate .

[0186] S73: Cumulative Number of Backflush Attempts Second-rate.

[0187] S74: Average operating temperature during operation ℃.

[0188] S75: Rate of increase in differential pressure over the past 24 hours Pa / h.

[0189] S76: Residual Pressure Differential Rating point.

[0190] S77: Recovery Rate Score point.

[0191] S78: Number of backflushes scored point.

[0192] S79: Temperature Rating point.

[0193] S710: Rate of Ascent Rating Score point.

[0194] S711: Filter Cartridge Health Rating point.

[0195] S712: Predicting Remaining Service Hour.

[0196] S713: Due to a health score of 80.9. 70 points. The touchscreen displays a green status, indicating that the filter is healthy and its estimated remaining lifespan is approximately 2.05 years.

[0197] S8: The system returns to step S2 to continue the filtration cycle, continuously monitors the pressure difference change, dynamically triggers backflushing, adaptively adjusts parameters, periodically assesses the health of the filter element, and achieves long-term maintenance-free operation.

[0198] Comparative Example 1 uses a traditional single-pore ceramic filter element, with other structures and control methods identical to Example 1. The difference lies in the ceramic filter element used in this system, which has a single-layer uniform pore structure. The entire 15mm thick filter element is sintered from ceramic material with an average pore size of 2μm, resulting in a porosity of 28%. The filter element lacks the gradient design of an outer coarse filtration layer and an inner fine filtration layer; all dust directly contacts the 2μm pore size filtration layer. The inner surface of the filter element is also coated with a dust-repellent nanocomposite coating. The automatic backflushing system employs a dual-peak synergistic pulse backflushing mechanism, and the control system utilizes differential pressure change rate prediction for intelligent backflushing triggering and multi-parameter lifespan prediction.

[0199] This comparative example lacks the pre-retention effect of an outer coarse filtration layer, allowing large dust particles to directly clog the 2μm pores on the filter element surface, resulting in a significantly faster rate of pressure differential increase compared to Example 1. The initial pressure differential change rate reached 2.5 Pa / s, far exceeding the 1.88 Pa / s of Example 1. Backflush triggering was more frequent, with an average backflush interval of only 12 minutes, compared to 25 minutes in Example 1. The single-pore structure significantly reduced the filter element's dust holding capacity; after 1000 hours of operation, the filter element health score was only 62.5 points, the pressure differential recovery rate dropped to 73.8%, and the predicted remaining lifespan was 8520 hours.

[0200] Comparative Example 2 uses a radial gradient pore size ceramic filter element, but the inner surface is not coated with a dust-repellent nanocomposite coating. Other structures and control methods are the same as in Example 1. The ceramic filter element used in Comparative Example 2 has the same three-layer gradient pore size structure as in Example 1, but the inner surface of the filter element is untreated, maintaining the original surface state of the ceramic with a surface energy of approximately 45 mN / m, much higher than the 18 mN / m after coating with the dust-repellent coating. The automatic backflushing system uses a dual-peak synergistic pulse backflushing, and the control system uses pressure difference change rate prediction for intelligent backflushing triggering and multi-parameter life prediction. This comparative example lacks the low surface energy effect of the dust-repellent coating, resulting in greater adhesion between the dust cake layer and the inner surface of the filter element. During backflushing, the dust cake layer is difficult to completely peel off, and the residual pressure difference increases significantly after backflushing. After 1000 hours of operation, the residual pressure difference after backflushing was measured to be 95 Pa, while in Example 1 it was only 35 Pa. The pressure difference recovery rate was 76.2%, lower than the 91.5% of Example 1. Due to incomplete backflushing cleaning, the pressure differential accumulates more rapidly, resulting in a filter health score of 68.3 and a predicted remaining lifespan of 13,140 hours. Backflushing energy consumption increases by approximately 18% because higher backflushing pressure and longer pulse times are required to overcome adhesion.

[0201] Comparative Example 3 uses a traditional fixed differential pressure threshold triggered backflushing control method, without using differential pressure change rate prediction. Other structures are the same as in Example 1. The system uses the same radial gradient pore size ceramic filter element and dust-repellent nanocomposite coating as in Example 1. The automatic backflushing system uses a dual-peak synergistic pulse backflushing method. However, the control system uses a traditional fixed differential pressure threshold triggering method, that is, backflushing is triggered immediately when the differential pressure reaches the set threshold of 600 Pa, without considering the differential pressure change rate or clogging stage. The system does not predict the remaining time to reach the threshold, nor does it distinguish between rapid clogging, normal clogging, and slow clogging stages, relying solely on the absolute value of the differential pressure. This comparative example does not have an advance prediction and staged triggering mechanism; the system only triggers backflushing when the differential pressure reaches the threshold. At this time, the filter element is already in a deep clogging state, with a thick and compacted dust cake layer. More energy is required during backflushing to remove deeply embedded dust, reducing the cleaning effect. After 1000 hours of operation, the differential pressure recovery rate was measured to be 82.7%, and the residual differential pressure after backflushing was 52 Pa. The fixed threshold method resulted in some backflushing occurring too late, causing irreversible blockage of the filter's micropores, resulting in a health score of 73.5 and a predicted remaining lifespan of 15,480 hours. Compared to the intelligent predictive triggering in Example 1, this method resulted in less regular backflushing frequency, with some backflushing intervals being too long, leading to deep blockage, while others were too short, causing unnecessary energy waste.

[0202] Comparative Example 4 uses a traditional single-peak pulse backflushing method, without employing dual-peak synergistic pulse backflushing; other structures are the same as in Example 1. The system uses the same radial gradient pore size ceramic filter element and dust-repellent nanocomposite coating as in Example 1, and the control system employs intelligent backflushing triggering based on differential pressure change rate prediction. However, the automatic backflushing system is only equipped with one electromagnetic pulse valve with a valve orifice diameter of 40 mm, generating a single pulse airflow for backflushing. The pulse pressure is 0.6 MPa, and the duration is 0.3 s. This single-peak pulse is responsible for both dust cake layer stripping and dust removal, lacking the synergistic effect of the first peak high-pressure impact stripping and the second peak high-flow removal in Example 1. During backflushing in Comparative Example 4, the dust cake layer stripping is not thorough enough; some of the stripped dust is not completely blown into the ash hopper and remains on the filter element surface or redeposits. After 1000 hours of operation, the differential pressure recovery rate was measured to be 84.3%, and the residual differential pressure after backflushing was 48 Pa. Incomplete dust removal led to a gradual reduction in the filter's dust-holding capacity, resulting in a health score of 74.8 and a predicted remaining lifespan of 16,320 hours. Although backflushing energy consumption was about 12% lower than the dual-peak method, the poor dust removal effect required more frequent backflushing, actually increasing the total energy consumption by about 8%.

[0203] Comparative Experiment: The following comparative experiments were designed to test and compare the system performance of Example 1 with Comparative Examples 1 to 4. Experimental Conditions: All experiments were conducted under the same simulated blast furnace gas purification conditions: inlet gas temperature 650±5℃, dust concentration 80±3g / m³. 3Handling air volume of 50000±200m³ 3 The runtime is 1000 hours. Each experiment uses 3 parallel samples, and the average value is taken as the test result.

[0204] Experimental Methods and Standards: Experiment 1, Filtration Efficiency Test: The dust concentration at the system outlet was tested according to the methods specified in GB / T6719-2009 "Technical Requirements for Bag Filters". Under stable system operation, isokinetic sampling was used to uniformly sample the cross-section of the outlet duct for at least 30 minutes. The collected gas was weighed and analyzed after passing through the filter membrane to determine the dust concentration. The formula for calculating the filtration efficiency is: ,in The concentration of dust at the inlet. This refers to the dust concentration at the outlet.

[0205] Experiment 2, Differential Pressure Characteristic Test: A differential pressure sensor with an accuracy of 0.5 grade was used to continuously monitor the differential pressure across the filter element. The differential pressure rise curve was recorded from the system's operation in a clean state to the first backflushing trigger, and the average differential pressure rise rate was calculated. Simultaneously, all backflushing events during 1000 hours of operation were recorded, and the average backflushing interval and total number of backflushing events were calculated.

[0206] Experiment 3, Backflushing Cleaning Efficiency Test: The pressure difference was measured before and after each backflushing, and the pressure difference recovery rate was calculated. Five backflushing events were selected at the 200th, 400th, 600th, 800th, and 1000th hours of operation. The pressure difference before backflushing, the pressure difference after backflushing, and the pressure difference recovery rate were recorded, and the trend of the cleaning effect with the operating time was analyzed.

[0207] Experiment 4, Filter Cartridge Lifespan Test: Following the filter media lifespan test method specified in ISO 11057:2011 "Air quality - Test methods for filtration properties of washable filter media", the filter cartridge health status was evaluated after 1000 hours of continuous operation. Characteristic parameters such as residual pressure difference after backflushing, pressure recovery rate, and cumulative number of backflushing cycles were measured. The multi-parameter health scoring method of this invention was used to calculate the filter cartridge health score, and the remaining lifespan was predicted based on the linear lifespan model.

[0208] Experiment 5, Energy Consumption Test: Install a flow meter and pressure gauge on the backflushing air line. Record the amount of compressed air used for each backflushing operation according to the measurement methods in GB / T13277-2015 "Compressed Air Part 1: Pollutant Purification Grades". Calculate the total energy consumption of backflushing during 1000 hours of operation, determine the energy consumption per unit volume of air processed, and conduct an economic comparative analysis.

[0209] Table 1. Filtration efficiency comparison test results

[0210]

[0211] As shown in Table 1, the outlet dust concentration in Example 1 was 8.5 mg / m³. 3 The filtration efficiency reached 99.989%, and the removal rate of 0.3μm ultrafine particles reached 99.95%, indicating that the three-layer gradient pore size filter cartridge achieved efficient graded filtration. Comparative Example 1 used a single pore size filter cartridge, and the outlet dust concentration was 9.8mg / m³. 3 Although the overall filtration efficiency was similar, the removal rate of 0.3μm ultrafine particles was only 99.82%, lower than that of Example 1. This is because a single 2μm pore size filter element lacks an inner 0.5μm fine filtration layer, resulting in insufficient capture capacity for ultrafine particles. The filtration efficiencies of Comparative Examples 2 and 3 were close to those of Example 1, indicating that the differences in dust-repellent coating and backflushing control methods mainly affect the dust removal effect and service life, with a smaller impact on the initial filtration efficiency. The gradient pore size design of Example 1, through a graded interception mechanism of outer coarse filtration, middle medium filtration, and inner fine filtration, ensured high filtration efficiency while preventing large dust particles from directly clogging the inner fine pores, laying the foundation for long-term stable operation.

[0212] Table 2 Comparison of Pressure Difference Characteristics Test Results

[0213]

[0214] As shown in Table 2, the average pressure rise rate of Example 1 was 0.28 Pa / min, significantly lower than that of Comparative Example 1 (0.52 Pa / min) and Comparative Example 2 (0.35 Pa / min). This difference is mainly due to the synergistic effect of the gradient pore size filter element and the dust-repellent nano-coating in Example 1. The gradient pore size structure traps large dust particles in the outer layer, preventing direct blockage of the fine pores in the inner layer and reducing the pressure rise rate. The dust-repellent nano-coating reduces dust adhesion, making the dust cake layer loose and porous rather than compacted and dense, further slowing down the pressure rise. Comparative Example 1 used a single-pore size filter element, where all dust directly blocked the 2μm pores, resulting in a rapid increase in pressure. The average backflushing interval was only 15.6 minutes, and the number of backflushing cycles reached 3850 during 1000 hours of operation, which is 1.69 times that of Example 1. Frequent backflushing not only increases energy consumption but also accelerates the mechanical fatigue of the filter element. Comparative Example 2 lacked a dust-repellent coating, resulting in a tightly adhered dust cake layer. The pressure differential rise rate was 0.35 Pa / min, and the number of backflushing cycles was 2920, both higher than in Example 1. Comparative Example 3 used a fixed pressure differential threshold of 600 Pa to trigger backflushing, failing to intervene in dust removal in advance. This led to some filter elements being deeply clogged during backflushing. Although the number of backflushing cycles was lower, the dust removal effect was reduced, which is detrimental to the filter element's lifespan in the long run. Example 1, through intelligent prediction, triggered backflushing in advance when the pressure differential reached approximately 490 Pa, achieving dust removal even with slight clogging, balancing the backflushing frequency and dust removal effect. The pressure differential characteristics of Comparative Example 4 were similar to those of Example 1, indicating that the dual-peak backflushing method had little impact on the pressure differential rise rate, mainly affecting the dust removal effect.

[0215] Table 3 Comparison Test Results of Backflushing Cleaning Efficiency

[0216]

[0217] As shown in Table 3, the backflushing cleaning effect of Example 1 remained stable at different operating time points. After 200 hours of operation, the pressure difference before backflushing was 485 Pa, and after backflushing, it was 138 Pa, with a pressure recovery rate of 94.5%. After 1000 hours of operation, the pressure difference before backflushing was 490 Pa, and after backflushing, it was 155 Pa, with a pressure recovery rate of 90.5%, indicating minimal attenuation of the cleaning effect. This is attributed to the low surface energy of the dust-repellent nanocomposite coating and the efficient cleaning mechanism of the dual-peak synergistic pulse backflushing. Comparative Example 2 lacked a dust-repellent coating, resulting in a high adhesion force of the dust cake layer. After 200 hours of operation, the pressure difference was 172 Pa, rising to 230 Pa after 1000 hours, with the pressure recovery rate decreasing from 86.5% to 74.2%, indicating a significant deterioration in the cleaning effect. This is because dust gradually forms a firm adhesion on the original ceramic surface, making it difficult to completely peel off during backflushing. The residual dust gradually accumulates, leading to a reduction in the effective filtration area of ​​the filter element. Comparative Example 3 used a fixed differential pressure threshold of 600 Pa to trigger backflushing. During backflushing, the filter element was already deeply clogged, with a thick and compacted dust cake layer, making it difficult for backflushing energy to effectively transfer to the bottom of the dust cake. After 200 hours of backflushing, the differential pressure was 155 Pa, rising to 208 Pa after 1000 hours, indicating incomplete dust removal and a gradual increase in the base differential pressure. Comparative Example 4 used a single-peak pulse backflushing method, lacking the synergistic effect of the first peak high-pressure impact stripping and the second peak high-flow removal. Its backflushing effect was between that of Example 1 and Comparative Examples 2 and 3. Example 1's dual-peak synergistic backflushing used a first peak 0.68 MPa high-pressure pulse to generate a strong impact that stripped the dust cake, followed by a second peak 0.55 MPa high-flow pulse lasting 0.4 seconds to completely remove the stripped dust. The two pulses were spaced 0.1 seconds apart, creating a timing sequence that significantly improved the dust removal efficiency compared to the single-peak method. The synergistic effect of the dust-repellent coating and dual-peak backflushing is the key technical means for Example 1 to maintain a long-term stable dust removal effect.

[0218] Table 4. Filter Cartridge Health Assessment Results After 1000 Hours of Operation

[0219]

[0220] As shown in Table 4, after 1000 hours of operation, the filter element health score of Example 1 reached 80.9 points, with a predicted remaining service life of 17914 hours and a total service life of approximately 18914 hours, equivalent to 2.16 years of continuous operation, significantly better than the comparative examples. Comparative Example 1, using a single-pore size filter element, had a residual pressure difference as high as 82 Pa after backflushing, a pressure recovery rate of only 73.8%, a cumulative backflushing count of 3320 times, a health score of only 62.5 points, and a predicted total service life of 10870 hours, only 57.5% of Example 1. The fundamental reason for this difference is that the single-pore size filter element lacks a gradient filtration structure, allowing large dust particles to directly clog the 2μm pores, causing irreversible deep clogging, a continuously decreasing pressure recovery rate, and frequent backflushing exacerbating filter element mechanical fatigue, significantly shortening its service life. Comparative Example 2, lacking a dust-repellent coating, had a residual pressure difference of 110 Pa after backflushing, a pressure recovery rate of 76.2%, a health score of 68.3 points, and a predicted total service life of 14140 hours, which is 74.8% of Example 1. Strong dust adhesion to the ceramic surface leads to incomplete cleaning, and residual dust accumulation occupies the dust-holding space of the filter element, accelerating performance degradation. Comparative Example 3 uses a fixed differential pressure threshold for triggering; backflushing after deep clogging causes significant mechanical stress on the filter element, and cleaning is incomplete, resulting in a health score of 73.5 and a predicted total lifespan of 16480 hours, which is 87.1% of Example 1. Comparative Example 4 uses single-peak backflushing, which has a weaker cleaning effect than the dual-peak method, resulting in a health score of 74.8 and a predicted total lifespan of 17320 hours, which is 91.6% of Example 1. Example 1 fully utilizes the filter element thickness for dust holding through a graded retention mechanism of gradient pore size filter elements; the dust-repellent coating reduces adhesion and facilitates cleaning; differential pressure change rate prediction enables early cleaning in cases of mild clogging to avoid deep clogging; dual-peak synergistic backflushing ensures thorough cleaning; and the multi-parameter fusion health assessment accurately reflects the true state of the filter element.

[0221] Table 5. Energy Consumption Comparison Test Results After 1000 Hours of Operation

[0222]

[0223] As shown in Table 5, the backflushing energy consumption per unit processing gas volume in Example 1 is 38.8 m³. 3 / 10 6 m 3 This is significantly lower than the 63.1m of Comparative Example 1. 3 / 10 6 m 3 Comparative Example 2: 55.5m 3 / 10 6 m 3 Compared to Comparative Example 3, 54.1m 3 / 10 6 m 3Comparative Example 1, due to the use of a single-pore size filter element, experienced a rapid increase in pressure differential, leading to frequent backflushing. It underwent 3850 backflushing cycles within 1000 hours, although the air consumption per cycle was relatively low (0.82m³). 3 However, the total air consumption for backflushing reached 3157 m³. 3 The energy consumption is 62.6% higher than that of Example 1. Based on the industrial compressed air cost of 0.24 yuan / m³... 3 Calculations show that Comparative Example 1 incurs approximately 58,000 yuan in additional energy costs annually (8760 hours). Comparative Example 2 lacks a dust-repellent coating, making dust removal difficult and requiring higher backflushing pressure and longer pulse times, with a single air consumption of 0.95 m³ / h. 3 Furthermore, due to the increased number of backflushing cycles, the total energy consumption was 43.0% higher. Comparative Example 3, using a fixed threshold trigger, required even more energy to overcome adhesion during backflushing in a deeply clogged state, resulting in a single air consumption of 1.02 m³. 3 The total energy consumption was 39.4% higher. Comparative Example 4 used single-peak backflushing, although the single-cycle gas consumption was lower (0.75m³). 3 However, incomplete dust removal leads to increased backflushing frequency, and the actual total energy consumption is only 4.1% lower than that of Example 1. Considering the increased replacement cost due to the shorter filter life, the overall economic efficiency is not superior to Example 1. Example 1 achieves dual optimization of backflushing frequency and energy consumption per cycle through multiple technologies, including gradient pore size filter elements to reduce the rate of pressure rise, pressure change rate prediction for timely backflushing, dust-repellent coating to improve dust removal efficiency, and dual-peak synergistic backflushing to optimize energy utilization. Experimental data shows that Example 1 achieves the lowest backflushing energy consumption and the best overall economic benefits while ensuring excellent filtration effect and ultra-long filter life, fully verifying the advanced nature of the technical solution of this invention.

[0224] The three-layer gradient pore structure of this invention—an outer coarse filtration layer, a middle medium filtration layer, and an inner fine filtration layer—achieves graded retention of large, medium, and fine particles, avoiding the problem of large particles directly clogging the fine pores in a single-pore filter element. Experimental data shows that the pressure difference rise rate (0.28 Pa / min) of Example 1 is only 53.8% of that of the single-pore comparative example 1 (0.52 Pa / min), the backflushing interval is extended by 68.6%, and the filter element life is increased by 73.9%. The gradient pore structure fully utilizes the entire thickness of the filter element for dust holding, significantly improving dust holding capacity, which is a key factor in achieving a long lifespan.

[0225] The dust-repellent nanocomposite coating significantly improves the backflushing cleaning effect by reducing dust adhesion through lower surface energy. Experimental data show that the residual pressure difference (35 Pa) after backflushing in Example 1 with the coating is much lower than that in Comparative Example 2 without the coating (110 Pa), with a pressure difference recovery rate 20.1 percentage points higher. The coating reduces the adhesion force between the dust cake layer and the filter element surface from 45 mN / m to 18 mN / m, a reduction of 60%, making it easier for dust to peel off and be removed during backflushing, avoiding performance degradation caused by residual dust accumulation. The low surface energy characteristics of the coating and the hierarchical filtration of the gradient pore structure work synergistically to ensure efficient capture of fine particles while facilitating backflushing cleaning, achieving an optimal balance between filtration and cleaning.

[0226] The intelligent backflush triggering mechanism based on differential pressure change rate prediction achieves adaptive dust removal control. Experimental data shows that Example 1, which uses differential pressure change rate prediction, dynamically adjusts the backflush timing according to the clogging rate, intervening in dust removal in advance during the rapid clogging stage, avoiding the problem of deep filter clogging in the fixed threshold triggering method. Compared with Comparative Example 3, which uses fixed threshold triggering, Example 1's dust removal is more timely, avoiding deep irreversible clogging, and increasing filter life by 14.8%. Differential pressure change rate prediction not only monitors the absolute value of differential pressure but also focuses on the trend of differential pressure change. By using a linear prediction model to calculate the remaining time to reach the threshold in advance, it realizes the transformation from passive response to proactive prevention.

[0227] The dual-peak synergistic pulse backflushing method significantly improves the thoroughness of dust removal by coordinating the timing of the first peak's high-pressure impact stripping and the second peak's high-flow-rate removal. Experimental data shows that the differential pressure recovery rate of Example 1 (91.5%) of the dual-peak synergistic backflushing method is higher than that of Comparative Example 4 (84.3%) of the single-peak backflushing method, and the residual differential pressure is reduced by 38.2% after backflushing. The first electromagnetic pulse valve generates a high-pressure pulse (0.68MPa, 135m / s) at its small valve port, which instantly impacts and strips the dust cake. The second electromagnetic pulse valve generates a high-flow-rate pulse (0.55MPa, 1.8 times the flow rate) at its large valve port for continuous removal. The two pulses are spaced 0.1 seconds apart, forming a synergistic effect. The stripping and removal processes each have their own focus and are closely linked, resulting in a dust removal effect that is superior to the pressure and flow rate compromise design of the single-peak method. The combination of dual-peak synergistic backflushing and the low adhesion characteristics of the dust-repellent coating further amplifies the dust removal advantages.

[0228] A multi-parameter fusion method for filter element health assessment and lifespan prediction enables precise maintenance decision support. Experimental verification shows that a weighted scoring model using five characteristic parameters—residual pressure difference after backflushing, pressure recovery rate, cumulative number of backflushing cycles, average operating temperature, and pressure rise rate—comprehensively reflects the true health status of the filter element. The health score is highly correlated with the remaining lifespan of the filter element, demonstrating high predictive accuracy. A tiered early warning mechanism notifies maintenance personnel to arrange replacement when the health score drops below 70, avoiding resource waste caused by premature replacement and preventing production accidents due to filter element failure.

[0229] From a comprehensive economic perspective, although the manufacturing cost of gradient pore size ceramic filter elements and dust-repellent nano-coatings is slightly higher than that of traditional filter elements, the operating cost is significantly reduced by extending service life and lowering backflushing energy consumption. Experimental data shows that the filter element life of Example 1 is approximately 18,914 hours, which is 1.74 times that of Comparative Example 1, equivalent to a 42.5% reduction in filter element cost per unit time. Backflushing energy consumption is reduced by 37.7% compared to Comparative Example 1.

[0230] It can be seen that the system of the present invention is superior to traditional technologies in terms of filtration efficiency, pressure difference characteristics, dust removal effect, filter life and energy consumption. It achieves efficient purification of high-temperature dust-laden gas and long-term maintenance-free operation of the system, and has significant technological advancement and economic practicality, providing an excellent solution for the field of high-temperature dust removal.

[0231] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-temperature resistant, maintenance-free nanofiltration system, comprising a filter body and a control system, characterized in that, It also includes nano-ceramic filter cartridges and an automatic backflush system, wherein: The dust filter body includes an air inlet chamber, a filter chamber, and an air outlet chamber, which are separated by a partition and connected in sequence. The air inlet chamber is provided with an air inlet, the air outlet chamber is provided with an air outlet, and the bottom of the dust filter body is provided with a dust hopper, and the bottom of the dust hopper is provided with a dust discharge valve. The nano-ceramic filter element assembly includes multiple radial gradient pore size nano-ceramic filter elements. Each filter element has a cylindrical structure and is installed in the filter chamber. The two ends of the filter element are respectively sealed to the air inlet chamber and the air outlet chamber. Each filter element includes an outer coarse filtration layer, a middle medium filtration layer and an inner fine filtration layer from the outside to the inside. The average pore size of the three layers decreases sequentially. The inner surface of the filter element is coated with a dust-repellent nano-composite coating. The automatic backflush system includes a high-pressure air source, a backflush air path, a first electromagnetic pulse valve, a second electromagnetic pulse valve, a backflush nozzle, and a differential pressure sensor. The high-pressure air source is connected in series with the first electromagnetic pulse valve and the second electromagnetic pulse valve through the backflush air path. The second electromagnetic pulse valve is connected to the backflush nozzle through the backflush air path. The outlet of the backflush nozzle faces the inner surface of the filter element. The two measuring ports of the differential pressure sensor are respectively located on the outer and inner sides of the filter element. The control system is electrically connected to the differential pressure sensor, the first electromagnetic pulse valve, and the second electromagnetic pulse valve. The control system continuously collects differential pressure data and calculates the differential pressure change rate. Based on the differential pressure change rate, it predicts the remaining time to reach the differential pressure threshold and determines the backflush triggering time. It controls the opening sequence of the first electromagnetic pulse valve and the second electromagnetic pulse valve to form a double-peak pulse backflush airflow. It calculates the differential pressure recovery rate before and after backflush and adjusts the backflush parameters based on the evaluation results. It collects multiple characteristic parameters to calculate the filter element health score and predict the remaining service life. The outer coarse filtration layer, the middle medium filtration layer, and the inner fine filtration layer are integrally sintered, with the outer coarse filtration layer used for interception. The above-mentioned large particulate dust, the middle medium filter layer is used to intercept it. Medium-grade dust, the inner fine filter layer is used to trap... Fine dust particles are filtered through a three-layer gradient pore size gradation system to prevent large dust particles from directly clogging the fine pores of the inner layer; the dust-repellent nanocomposite coating is chemically bonded to the inner surface of the filter element, and the low surface energy groups on its surface reduce the adhesion between the dust and the inner surface of the filter element, allowing the dust cake to peel off during backflushing; the valve port size of the second electromagnetic pulse valve is larger than that of the first electromagnetic pulse valve, forming different pressure characteristics of the first peak stripping pulse and the second peak removal pulse.

2. The high-temperature resistant, maintenance-free nanofiltration system according to claim 1, characterized in that, The control system includes a PLC controller, a touch screen, an alarm module, a data acquisition module, a differential pressure change rate calculation unit, a backflushing trigger judgment unit, a backflushing timing control unit, a backflushing effect evaluation unit, and a filter cartridge life prediction unit. The touch screen is connected to the PLC controller for setting operating parameters and displaying real-time data. The alarm module is connected to the PLC controller for abnormal status alarms. The ash discharge valve is controlled by the PLC controller. The data acquisition module is connected to the differential pressure sensor signal for continuous differential pressure data acquisition. The differential pressure change rate calculation unit is connected to the data acquisition module. The backflushing trigger judgment unit is connected to the differential pressure change rate calculation unit. The connection is used to predict the remaining time to reach the differential pressure threshold based on the differential pressure change rate and to determine the backflush triggering timing. The backflush timing control unit is connected to the PLC controller and electrically connected to the first and second electromagnetic pulse valves respectively to independently control the opening time and opening duration of the two electromagnetic pulse valves. The backflush effect evaluation unit is connected to the data acquisition module and the backflush timing control unit to calculate the differential pressure recovery rate before and after backflush and send parameter adjustment instructions to the backflush timing control unit according to the evaluation results. The filter element life prediction unit is connected to the data acquisition module to collect multiple characteristic parameters to calculate the filter element health score and predict the remaining service life.

3. The high-temperature resistant, maintenance-free nanofiltration system according to claim 2, characterized in that, The filter cartridge life prediction unit includes a feature parameter acquisition module, a health rating module, and a remaining life calculation module. The feature parameter acquisition module is connected to the data acquisition module and the temperature sensor signal to acquire residual pressure difference after backflushing, pressure difference recovery rate, cumulative number of backflushing cycles, average operating temperature, and pressure difference rise rate. The health rating module is connected to the feature parameter acquisition module to perform normalized scoring calculations on each feature parameter and calculate the filter cartridge health rating by weighted summation. The remaining life calculation module is connected to the health rating module to calculate and predict the remaining service life based on the health rating and provide early warning.

4. A high-temperature resistant, maintenance-free nanofiltration method, characterized in that, The high-temperature resistant, maintenance-free nanofiltration system according to any one of claims 1-3 shall be implemented according to the following steps: S1: Set operating parameters and measure the initial differential pressure of the clean filter element via the touch screen; S2: Start the filtration cycle. Dust-laden gas enters the filtration chamber from the inlet chamber and passes through the three layers of the filter element for graded interception. Clean gas is discharged from the outlet chamber. S3: The differential pressure sensor continuously measures the pressure difference across the filter element. The data acquisition module collects the differential pressure data and transmits it to the differential pressure change rate calculation unit for differential pressure change rate calculation. S4: The backflush triggering judgment unit predicts the remaining time to reach the pressure difference threshold based on the pressure difference change rate, and determines the timing of backflush triggering based on the magnitude of the pressure difference change rate to determine the blockage stage. S5: After receiving the backflush trigger signal, the backflush timing control unit controls the backflush process. First, it closes the intake valve, and then controls the first electromagnetic pulse valve and the second electromagnetic pulse valve to open and close in sequence according to the set timing to form a double-peak coordinated backflush airflow. After the backflush is completed, the intake valve is reopened. S6: The backflush effect evaluation unit collects the pressure difference value before and after backflush, calculates the pressure difference recovery rate, and adjusts the pressure and duration parameters of the next backflush according to the magnitude of the pressure difference recovery rate. S7: The filter life prediction unit collects multiple feature parameters, calculates the filter health score using a weighted scoring method, and predicts the remaining service life of the filter based on the health score to issue an early warning. S8: Return to step S2 to continue the filtration cycle until the filter health score drops to the scrap threshold, prompting you to replace the filter.

5. The high-temperature resistant, maintenance-free nanofiltration method according to claim 4, characterized in that, Step S1 includes the following specific operations: S11: Input differential pressure threshold via touchscreen ,in This is the differential pressure threshold, in Pa, with a set range of 500-800 Pa. S12: Input the threshold for the rate of change of rapid choking pressure differential. ,in The threshold for the rate of change of differential pressure during rapid blockage, in Pa / s, is set to 1.5 Pa / s. S13: Input the threshold for the rate of change of slow blockage pressure differential ,in The threshold for the rate of change of differential pressure during slow blockage, in Pa / s, is set to 0.5 Pa / s. S14: Input the upper limit of the backflush interval time ,in This is the upper limit of the backflush interval time, in minutes, with a setting range of 10-60 minutes; S15: Start the system and introduce clean gas at the rated flow rate in clean mode. The differential pressure sensor measures the pressure difference across the filter element at this time, and the PLC controller records this pressure difference as the initial pressure difference. ,in This represents the initial pressure difference, in Pa; this completes system initialization and baseline value establishment.

6. The high-temperature resistant, maintenance-free nanofiltration method according to claim 4, characterized in that, Step S3 includes the following specific operations: S31: The differential pressure sensor continuously measures the pressure difference between the outer and inner sides of the filter element with a sampling period of 1 second to obtain the real-time differential pressure value. ,in This represents the pressure difference at the current moment, in Pa. S32: The data acquisition module transmits the differential pressure data to the differential pressure change rate calculation unit; S33: The pressure difference change rate calculation unit uses moving average filtering and differential algorithm to calculate the pressure difference change rate. First, it calculates the moving average of the pressure difference at the current moment. ,in This represents the pressure difference at the current moment, in Pa. This is the pressure difference value from the previous second, in Pa. This is the pressure difference value for the first two seconds, in Pa. This is the pressure difference value for the first three seconds, in Pa. The pressure difference is the value over the first four seconds, in Pa; 5 is the size of the moving average window. The moving average of the differential pressure at the current moment, in Pa; then calculate the rate of change of differential pressure. ,in This is the moving average of the differential pressure at the current moment, in Pa. The moving average of the differential pressure 5 seconds ago, in Pa; 5 represents the time interval, in seconds. This is the rate of change of pressure difference, in Pa / s; Real-time monitoring of differential pressure change trends.

7. The high-temperature resistant, maintenance-free nanofiltration method according to claim 4, characterized in that, Step S4 includes the following specific operations: S41: The backflush trigger judgment unit obtains the current differential pressure change rate from the differential pressure change rate calculation unit. and current pressure difference ,in This represents the current rate of change of differential pressure, in Pa / s. This is the current pressure difference, in Pa. S42: Calculate the arithmetic mean of the rate of change of pressure difference for the most recent 10 samples. ,in This represents the average rate of change of pressure difference, in Pa / s. S43: Calculate the remaining forecast time based on the linear forecasting model. ,in This is the differential pressure threshold, in Pa. This is the current pressure difference, in Pa. This represents the average rate of change of pressure difference, in Pa / s. To predict the remaining time, the unit is seconds; if If so, it will directly trigger a backflush; S44: Determine the current rate of change of differential pressure relative to the threshold. , The relationship, among which The threshold for the rate of change of differential pressure during rapid blockage, in Pa / s; The threshold for the rate of change of differential pressure during slow blockage, in Pa / s; S45: If It is determined to be in the rapid congestion phase, when achieve A pre-flush trigger signal is issued at the appropriate time; S46: If This is determined to be a normal congestion phase. achieve A backflush trigger signal is issued at the appropriate time; S47: If It is determined to be in the slow congestion stage. achieve A backflush trigger signal is issued at the appropriate time; S48: Or when the runtime reaches Regardless of the pressure difference, a backflush trigger signal is issued, in which... This is the upper limit of the backflush interval time, in minutes; This allows for early dust removal when the filter element is only slightly clogged, preventing deep clogging from reducing the backflushing effect.

8. The high-temperature resistant, maintenance-free nanofiltration method according to claim 4, characterized in that, Step S6 includes the following specific operations: S61: Before step S5 begins, the backflush effect evaluation unit obtains the current differential pressure value from the data acquisition module and records it as the differential pressure before backflush. ,in The pressure difference before backflushing is expressed in Pa. S62: After step S5 ends and the filtration operation stabilizes, obtain the current differential pressure value from the data acquisition module and record it as the differential pressure after backflushing. ,in This represents the pressure difference after backflushing, in Pa. S63: Calculate the differential pressure recovery rate ,in The pressure difference before backflushing is expressed in Pa. This represents the pressure difference after backflushing, in Pa. This is the initial pressure difference, in Pa. The differential pressure recovery rate is expressed in % (%). S64: Set target recovery rate Calculation error ,in The target recovery rate is expressed as % . The error is expressed in %; S65: Adjust the backflush parameters based on the error, and calculate the backflush pressure adjustment amount. ,in This is the proportionality coefficient; This is the backflush pressure adjustment amount, in %; then adjust the first peak pressure of the next backflush to... The second peak pressure is ,in The pressure at the first peak is measured in Pa. The pressure of the second peak is expressed in Pa; the duration of the second peak is also adjusted. ,in The duration of the second peak, in seconds; The error is expressed in %; S66: Completes adaptive parameter optimization based on backflushing effect to achieve the optimal balance between dust removal effect and energy consumption.

9. The high-temperature resistant, maintenance-free nanofiltration method according to claim 4, characterized in that, Step S7 includes the following specific operations: S71: The characteristic parameter acquisition module obtains the residual pressure difference after the latest backflush from the data acquisition module. ,in The residual pressure difference after backflushing is expressed in Pa. S72: Obtain the latest differential pressure recovery rate from the backflush effect evaluation unit. ,in This refers to the differential pressure recovery rate. S73: Obtain the cumulative number of backflush cycles from the PLC controller ,in This refers to the cumulative number of backflush attempts; S74: Calculate the average operating temperature from all temperature samples taken during operation. ,in The average operating temperature is expressed in °C. S75: The rate of increase in pressure differential is obtained by linear fitting of the pressure differential data over the past 24 hours. ,in This represents the rate of increase in pressure differential, expressed in Pa / h. S76: The health assessment module performs normalized scoring calculations for each parameter, and the residual pressure difference score is: ,in The residual pressure difference after backflushing is expressed in Pa; 500 is the residual pressure difference limit, also expressed in Pa. It is a function for maximizing the value; It is a minimum value function; Score the residual pressure difference; S77: Recovery Rate Score ,in This refers to the differential pressure recovery rate. It is a function for maximizing the value; It is a minimum value function; Score the recovery rate; S78: Number of backflushes scored ,in This represents the cumulative number of backflush operations; 10000 is the limit for the number of backflush operations, which is dimensionless. It is a function for maximizing the value; It is a minimum value function; The number of backflips is scored, with points as the unit; S79: Temperature Rating ,in The average operating temperature is expressed in °C; 850 is the upper limit of the temperature range, expressed in °C. It is a function for maximizing the value; It is a minimum value function; Temperature is rated in points. S710: Rate of Ascent Rating Score ,in The pressure differential rise rate is expressed in Pa / h; 10 represents the rise rate limit, also in Pa / h. It is a function for maximizing the value; It is a minimum value function; The rate of ascent is scored, with points as the unit; S711: Uses a weighted summation method to calculate the filter health score. ,in , , , , This is a weighting factor, which is adjusted based on the filter type. Rate the health of the filter cartridge; S712: The remaining lifespan calculation module calculates and predicts the remaining lifespan based on the health score. ,in Rate your current health status in points; 40 is the scrapping threshold, in cents; 100 represents the initial health level, expressed in points. 26280 is the rated lifespan, in hours, calculated as 3 years × 365 days / year × 24 hours / day; To predict remaining useful life, the unit is hours; if ,but ; S713: If The screen displays a green status indicator to show the filter's health. S714: If The screen displays a yellow status and prompts you to replace the filter within one month. S715: If When the screen displays a red status and triggers the alarm module to issue an audible and visual alarm, the filter element needs to be replaced immediately. Complete the health status assessment and remaining life prediction of filter element based on multi-parameter fusion, and realize the determination of when to replace filter element.

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