Quality inspection early warning system for impregnated paper production

Abstract

The invention discloses a quality inspection and early warning system for impregnated paper production, and relates to the field of quality inspection and early warning for impregnated paper production, and the method comprises the steps: directly measuring the real liquid pressure intensity of a paper immersion area through an impregnation parameter collection module, and generating a dynamic pressure intensity deviation in combination with the theoretical pressure intensity calculated by a dynamic pressure intensity calibration module; the valve opening reference value is matched based on the dynamic pressure deviation, the solvent flow is corrected in real time in combination with the liquid level change rate, and the precipitation risk is evaluated by analyzing the concentration reduction amplitude after solvent supplementation and the duration required by solution stabilization; when the risk reaches an activation condition, triggering an anti-precipitation instruction, according to the anti-precipitation instruction, linking a stirrer to stir in a production intermittent period, and injecting a solute to ensure that the concentration reaches the standard; and recording the water level adjusting time length, the concentration compensation time length and the instruction response time length, triggering graded alarm when time is out, and outputting an interrupt reset instruction to a corresponding adjusting module. And the quality control level in the impregnated paper production process is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of quality inspection and early warning for impregnated paper production, and relates to a quality inspection and early warning system for impregnated paper production. Background Art

[0002] Impregnated paper is a specialty paper made by impregnating base paper in a synthetic resin solution, followed by drying and curing. Due to its enhanced physical properties, such as water resistance, abrasion resistance, and tear strength, this paper is widely used in applications such as wood-based panel veneer, laminate flooring, furniture edge banding, and fireproof board substrates. Because the quality of impregnated paper is directly linked to its application and the quality of the final product, strict quality inspections and early warnings throughout the production process are crucial.

[0003] Currently, quality control for impregnated paper production primarily relies on a series of tests on the finished paper after processing. These tests include thickness measurement, water resistance testing, peel strength testing, and other physical and chemical property tests. These tests are then used to retrospectively analyze potential issues that may have occurred during the impregnation process. However, quality risks caused by fluctuations in production parameters are not discovered until the finished product is formed. This not only wastes raw materials such as base paper and impregnation solution, but can also lead to batches of substandard products due to accumulated problems, increasing production costs.

[0004] However, as the impregnation step is a crucial step in the production of impregnated paper, its quality inspection has become a key indicator of impregnated paper production quality inspection. Although existing technologies have attempted to monitor and adjust impregnation process parameters, the following key issues remain: First, existing technologies mainly rely on liquid level sensors to monitor static liquid height, which makes it difficult to reflect the local liquid pressure in the actual immersed area of ​​the paper in real time. When the paper's running speed changes, its position shifts, or the liquid level fluctuates, the liquid level alone cannot accurately assess the paper's actual loading state and impregnation uniformity.

[0005] Secondly, existing rehydration or concentration adjustment is usually triggered based on a simple deviation threshold between the parameter setting value and the detection value. Although adding solvent can restore the liquid level, it will cause the solution concentration to drop instantaneously. The lack of scientific assessment and preventive measures for the risk of solute precipitation increases the risk of solute precipitation, causing the precipitate to adhere to the paper surface to form spots, particles, foreign matter and other appearance defects.

[0006] In addition, the existing technology is relatively independent of each control link and lacks time-sensitive monitoring of adjustment behavior. It is difficult to diagnose specific fault points in a timely manner and trigger targeted closed-loop reset measures, which leads to the expansion of local problems and affects the overall process stability and quality controllability. Summary of the Invention

[0007] In view of this, in order to solve the problems raised in the above background technology, the present invention provides a quality inspection and early warning system for the production of impregnated paper.

[0008] The purpose of the present invention can be achieved through the following technical solutions: A quality inspection and early warning system for impregnated paper production includes: an impregnation parameter acquisition module for real-time acquisition of the liquid level height of the impregnation tank and the liquid pressure of the paper immersion area.

[0009] The dynamic pressure calibration module is used to calculate the theoretical pressure of the current immersion depth of the paper based on the real-time liquid level height and the density of the immersion liquid, and generate the dynamic pressure deviation between the liquid pressure and the theoretical pressure.

[0010] The water level intelligent adjustment module is used to drive the liquid filling valve opening adjustment through a dynamic mechanism when the dynamic pressure deviation exceeds the tolerance range, and to correct the solvent flow rate according to the rate of change of the liquid level.

[0011] The concentration-precipitation linkage module is used to detect the concentration drop after solvent replenishment, evaluate the precipitation risk by analyzing the concentration drop and the solution stability time, and trigger the anti-precipitation instruction when the risk reaches the activation condition.

[0012] The concentration dynamic compensation module is used to control the agitator to stir during the production interval according to the anti-sedimentation instruction, and to inject solute synchronously until the concentration of the impregnation liquid reaches the standard.

[0013] The quality inspection early warning intervention module is used to record the water level adjustment time, concentration compensation time and instruction response time. When any time exceeds the corresponding process time window, an abnormal alarm of the immersion process is triggered and an interrupt reset instruction is output to the corresponding step.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) The present invention directly measures the actual liquid pressure of the paper immersion area through the immersion parameter acquisition module, and generates a dynamic pressure deviation based on the theoretical pressure calculated by the dynamic pressure calibration module. This breaks through the limitation of relying solely on indirect estimation of the liquid level height, captures the paper position changes and immersion status in real time, provides a direct and accurate basis for water level adjustment, and significantly improves the perception accuracy of the controlled state of the immersion process.

[0016] (2) The present invention matches the valve opening reference value based on the dynamic pressure deviation, and corrects the solvent flow in real time in combination with the liquid level change rate. It analyzes the concentration drop after the solvent is added and the time required for the solution to stabilize to evaluate the precipitation risk, achieves accurate liquid level recovery, reduces overshoot oscillation, improves the regulation efficiency, and judges the precipitation risk level to achieve graded treatment of abnormal immersion liquid status, ensuring timely response when the risk really poses a threat.

[0017] (3) The present invention triggers the anti-precipitation instruction when the risk reaches the activation condition. According to the anti-precipitation instruction, the agitator is linked to stir during the production interval and solute is injected to ensure that the concentration meets the standard, thereby achieving high-precision dynamic and stable control of the concentration of the impregnation liquid and blocking the occurrence of solute precipitation defects from the root.

[0018] (4) The present invention records the water level adjustment time, concentration compensation time and instruction response time, triggers a graded alarm when the timeout occurs, and outputs an interrupt reset instruction to the corresponding adjustment module, quickly locates the faulty module and performs closed-loop recovery, preventing the expansion of local abnormalities and significantly improving process controllability and system robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 This is a schematic diagram of the connection of various modules of the system of the present invention.

[0021] Figure 2 This is a flow chart of the water level intelligent regulation module of the present invention.

[0022] Figure 3 This is a flow chart of the agitator linkage control of the present invention. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] See also Figure 1 As shown, the present invention provides a quality inspection and early warning system for impregnated paper production, comprising: an impregnation parameter acquisition module, a dynamic pressure calibration module, an intelligent water level adjustment module, a concentration-precipitation linkage module, a concentration dynamic compensation module, and a quality inspection and early warning intervention module. All modules are connected in the order described above.

[0025] The immersion parameter acquisition module is used to acquire the liquid level of the immersion tank and the liquid pressure of the paper immersion area in real time.

[0026] A specific implementation process for collecting the liquid level height of the immersion tank and the liquid pressure in the paper immersion area is as follows: multiple groups of miniature ultrasonic liquid level sensors are embedded along the length of the pool wall on the top of the two sides of the immersion tank parallel to the paper running track. The transmitting ends of all sensors are covered with a layer of hydrophobic ultrasonic transmitting material and are installed downward perpendicular to the liquid surface.

[0027] It's important to note that miniature ultrasonic level sensors reduce the adhesion of immersion liquid to the sensor surface, preventing residual liquid from interfering with ultrasonic transmission and ensuring accurate level measurement. Multiple groups of miniature ultrasonic level sensors are distributed along the track, dynamically switching their active areas as the paper shifts, accurately covering the current submerged area and resolving the issue of single-point sensors being unable to adapt to changes in paper position.

[0028] According to the preset width of the paper immersion area, the ultrasonic liquid level sensor at the corresponding position in the area is activated to output the measured value of the immersion tank liquid level in real time.

[0029] Specifically, the sensor emits ultrasonic pulses, which propagate vertically downward until they encounter the liquid surface. Once the ultrasonic pulses reach the liquid surface, some of the energy is reflected back to the sensor. Because the ultrasonic waves reflect at the interface between air and liquid, the sensor receives the return echo signal. The time difference between transmitting the ultrasonic wave and receiving the echo is recorded. This time difference is multiplied by the speed of the ultrasonic wave and divided by two, taking into account the round-trip path, to calculate the distance from the sensor to the liquid surface. Since the sensor is mounted in a fixed position, the actual liquid level can be calculated using a pre-set reference point.

[0030] A distributed pressure-sensitive film sensor array is embedded on a plane at the bottom of the immersion tank corresponding to the paper immersion area.

[0031] It should be noted that the distributed pressure-sensitive film sensor array can cover the entire plane of the paper immersion area and can simultaneously detect the liquid pressure at different positions in the area, avoiding measurement deviations caused by missed detection by single-point sensors or local pressure anomalies, and providing continuous raw data for subsequent calculation of dynamic pressure deviations.

[0032] The paper immersion area is the core area of ​​the impregnation process. The liquid pressure in this area directly affects the impregnation effect of the paper, such as the impregnation amount and uniformity. By placing sensors here, pressure data related to the paper impregnation status can be directly obtained.

[0033] The pressure data detected by the pressure-sensitive film sensor array is read in real time, and the original value of the liquid pressure in the paper immersion area is output after denoising.

[0034] Specifically, the thin film material of the distributed pressure-sensitive thin film sensor will change its electrical properties, such as resistance, under the pressure of the liquid, and the change is corresponding to the pressure, and the sensor converts the change into an electrical signal that can be collected, thereby obtaining the pressure data.

[0035] When the paper running position is offset, the pressure-sensitive thin film sensors outside the original immersion area are turned off, and the corresponding sensors of the new covered area are activated.

[0036] It should be noted that by real-time adapting the offset of the paper running position, it is ensured that the pressure-sensitive thin film sensor array always detects only the liquid pressure of the actual immersion area of the current paper, avoiding invalid data collection by the sensors outside the original immersion area, and activating the sensors of the new covered area to fill the detection range, thereby ensuring that the output liquid pressure original value can accurately correspond to the current immersion position of the paper, providing effective data for subsequent dynamic pressure deviation calculation, reducing the interference of irrelevant data on system analysis, and improving the dynamic response capability of the entire quality inspection and early warning system to the change of the paper position and the accuracy of data collection.

[0037] The dynamic pressure calibration module calculates the theoretical pressure of the current immersion depth of the paper according to the real-time liquid level height and the density of the immersion liquid, and generates the dynamic pressure deviation of the liquid pressure and the theoretical pressure.

[0038] The specific steps for obtaining the above-mentioned theoretical pressure are as follows: taking the liquid level height in the empty state of the immersion tank as the zero point reference, an absolute coordinate system of the liquid level height is established.

[0039] According to the real-time liquid level height and the fixed installation height of the paper in the immersion tank, the vertical distance between the lower surface of the paper and the current liquid level is dynamically calculated as the real-time immersion depth.

[0040] Specifically, the fixed installation height of the paper in the immersion tank is obtained from the pre-stored process parameters, the current immersion tank liquid level height measurement value output by the ultrasonic liquid level sensor in real time is read, and the fixed installation height of the lower surface of the paper is subtracted from the current real-time liquid level height. The difference obtained is the vertical distance between the lower surface of the paper and the current liquid level, which is the real-time immersion depth.

[0041] The calibration density value corresponding to the current immersion liquid is called from the pre-stored process parameter library.

[0042] The real-time immersion depth and the calibration density value are input into the hydrostatic relationship formula, and the theoretical pressure value corresponding to the current immersion depth of the paper is output.

[0043] The above-mentioned hydrostatic relationship formula refers to the liquid static pressure calculation formula , wherein, is the theoretical pressure corresponding to the current immersion depth of the paper, is the acceleration due to gravity, which is usually a constant, is the real-time immersion depth, is the calibrated density value.

[0044] The liquid pressure is instantaneously compared with the theoretical pressure value to generate a dynamic pressure deviation signal of the difference between the two.

[0045] The dynamic pressure calibration module not only ensures the quality and stability of the impregnation process by providing pressure comparison data, but also provides an important basis for subsequent automatic adjustment and process optimization.

[0046] The water level intelligent adjustment module is used to drive the liquid replenishment valve opening adjustment through a dynamic mechanism when the dynamic pressure deviation exceeds the tolerance range, and to correct the solvent flow rate according to the liquid level height change rate.

[0047] See also Figure 2 As shown, when a dynamic pressure deviation signal is received, it is verified that the duration of the signal exceeding the tolerance range within a predetermined time step reaches a minimum response threshold.

[0048] It should be noted that the predetermined time step is set to avoid misjudgment caused by instantaneous fluctuations. It is usually based on the short-term pressure fluctuation duration allowed in the impregnation process, calling the empirical value of the fluctuation period in the historical normal production data from the pre-stored process parameter library, or determining the time interval that can effectively distinguish between instantaneous interference and continuous anomalies through experiments.

[0049] The tolerance range is the maximum deviation range between the actual pressure and the theoretical pressure allowed by the process. It is determined based on the quality requirements of the impregnation process on the paper impregnation effect, such as impregnation uniformity and impregnation amount. The upper limit value of the pressure deviation that ensures qualified impregnation quality is retrieved from the process parameter library.

[0050] The minimum response threshold is the shortest duration of time required to trigger adjustment after the deviation exceeds the tolerance range. It is used to filter out short-term deviations, such as instantaneous fluctuations caused by liquid disturbances, to prevent frequent adjustments from affecting system stability.

[0051] During the period of out-of-tolerance, the polarity change of the dynamic pressure deviation for several consecutive sampling cycles is detected in real time. If the polarity is consistent, a unidirectional evolution flag is output; if the polarity is alternating, an oscillating evolution flag is output.

[0052] It should be noted that several sampling cycles are based on the sampling frequency and stability judgment requirements pre-stored in the process parameter library, such as 5 consecutive sampling cycles.

[0053] Polarity consistency means that the deviation polarity of several consecutive sampling periods is positive or negative, and the output unidirectional evolution flag corresponds to code X.

[0054] Polarity alternation means that the deviation polarity of several consecutive sampling periods alternates between positive and negative, such as positive, negative, positive or negative, positive, negative, etc. The output oscillation evolution mark corresponds to code Y.

[0055] Calculate the ratio of the range of dynamic pressure deviation to the time span in the current time window, map it to the predefined rate level table and output the rate level code.

[0056] A specific embodiment of the above mapping to the predefined rate level table output rate level code is as follows: in the predefined rate level table, a number of ranges of the ratio of the extreme difference to the time span, i.e., the deviation change rate range, are pre-divided. Each range corresponds to a unique rate level and code. For example: when the ratio is less than or equal to 0.3Pa / s, the corresponding low-speed change level output code is 01. When the ratio is between When the ratio is greater than 1.0Pa / s, it corresponds to the medium-speed change level output code 02, and when the ratio is greater than 1.0Pa / s, it corresponds to the high-speed change level output code 03.

[0057] The above ratio ranges, grade names and codes are all pre-stored in the process parameter library and are determined based on the matching experiments of the deviation change rate and the adjustment response in the historical process. During actual mapping, it is only necessary to classify the calculated ratio into the corresponding range to output the corresponding rate grade code.

[0058] The unidirectional evolution sign or the oscillatory evolution sign is combined with the rate level encoding to form the deviation evolution feature value.

[0059] Specifically, according to a preset combination rule, such as the format of flag code + rate level code, the two are concatenated into a string to form the deviation evolution feature value. For example, if the evolution is unidirectional and the rate level code is 02, the combination is X02; if the evolution is oscillatory and the rate level code is 03, the combination is Y03.

[0060] The corresponding reference valve opening value is matched from a preset opening adjustment mapping table according to the deviation evolution characteristic value.

[0061] A specific implementation example of the aforementioned valve opening value is as follows: Unidirectional evolution characteristic values ​​generally correspond to larger openings than oscillatory evolution characteristic values ​​at the same rate level. Furthermore, within the same evolution trend, higher rate levels correspond to larger opening values. For example, when the deviation evolution characteristic value is X01, it corresponds to a baseline valve opening value of 15%. Because the deviation changes slowly in one direction, small adjustments are required to avoid overshoot.

[0062] When the deviation evolution characteristic value is X02, the corresponding reference valve opening value is 40%. The deviation changes at a medium rate in one direction, and a medium amplitude adjustment is required to quickly correct the deviation.

[0063] When the deviation evolution characteristic value is X03, the corresponding reference valve opening value is 70%. The deviation changes rapidly in one direction and requires a large adjustment to curb the deviation expansion trend.

[0064] When the deviation evolution characteristic value is Y01, the corresponding reference valve opening value is 10%. The low-speed oscillation of the deviation requires very small adjustments to stabilize the system and avoid exacerbating the oscillation.

[0065] When the deviation evolution characteristic value is Y02, the corresponding reference valve opening value is 25%. The deviation medium-speed oscillation requires conservative adjustment to gradually converge the fluctuation.

[0066] When the deviation evolution characteristic value is Y03, the corresponding reference valve opening value is 50%. The deviation oscillates at high speed, and the adjustment range needs to be appropriately increased to quickly suppress the oscillation trend, but it must be lower than the unidirectional high-speed opening to avoid system instability.

[0067] If the liquid level height change rate is positive and exceeds the threshold reference opening value, the fixed compensation amount is lowered; if the liquid level height change rate is negative and exceeds the threshold reference opening value, the fixed compensation amount is increased.

[0068] Convert the compensated opening value into the valve opening instruction.

[0069] When the dynamic pressure deviation exceeds the tolerance range, the opening of the refill valve is dynamically adjusted and the solvent flow rate is corrected in combination with the rate of change of the liquid level height. The deviation between the actual liquid pressure and the theoretical pressure in the paper immersion area is quickly controlled within the tolerance range to ensure that the liquid level and the corresponding liquid pressure meet the process requirements, thereby stabilizing the impregnation effect of the paper and providing qualified impregnation basic conditions for subsequent process links.

[0070] The concentration-precipitation linkage module detects the concentration drop after solvent is added, evaluates the precipitation risk by analyzing the concentration drop and the solution stability time, and triggers the anti-precipitation instruction when the risk reaches the activation condition.

[0071] The specific steps for obtaining the concentration drop are as follows: when the valve opening instruction changes from zero to non-zero, the immersion liquid concentration at this moment is recorded as the reference concentration value.

[0072] After the opening of the monitoring refill valve returns to zero, the first delay timing is started and when the delay ends, the current concentration is recorded as the end concentration value.

[0073] The absolute concentration difference is obtained by subtracting the baseline concentration value from the end concentration value.

[0074] If the absolute concentration difference exceeds the preset minimum effective drop threshold, an effective drop signal is marked.

[0075] It should be noted that the preset minimum effective reduction threshold is determined by analyzing the correlation data between concentration changes and precipitation risks after solvent addition in historical normal production, so as to determine the minimum concentration difference that can reflect the actual impact of concentration reduction on solution stability.

[0076] If the duration of the concentration monitoring interruption is less than the maximum allowed interruption threshold, mark the data integrity signal.

[0077] It should be noted that the maximum allowed interruption threshold is determined by analyzing the correlation data between the duration of concentration monitoring interruption and the accuracy of the calculated concentration drop, and determining the maximum interruption duration that can still reliably reflect the concentration change even if the interruption occurs.

[0078] When the effective drop signal and the data integrity signal are received simultaneously, output the absolute concentration difference as the concentration drop.

[0079] The above-mentioned sedimentation risk obtaining step is as follows: based on historical normal production data, a concentration drop and stable duration relationship curve is established, and the dynamic qualified domain boundary of the current production cycle is output.

[0080] The above-mentioned qualified domain boundary refers to the concentration drop and stable duration combination interval that is free of sedimentation risk in the current production cycle.

[0081] The concentration drop and the measured solution stable duration form a two-dimensional coordinate point.

[0082] If the coordinate point is within the dynamic qualified domain boundary, output the no-risk identification, and if the coordinate point is outside the dynamic qualified domain boundary, output the sedimentation risk identification.

[0083] The minimum geometric distance value of the coordinate point deviating from the dynamic qualified domain boundary is obtained, and if the distance value does not exceed the preset near-end reference distance, the observation level response is triggered.

[0084] It should be noted that the preset near-end reference distance is usually based on statistical analysis of the risk-free and risky boundaries in historical normal production data, or by experiment to determine a critical distance value that can effectively distinguish between slight deviation and intervention deviation as the threshold for determining whether to trigger the observation level response.

[0085] If the distance value exceeds the preset near-end reference distance but does not exceed the preset far-end reference distance, the intervention level response is triggered.

[0086] It should be noted that the preset far-end reference distance is determined by statistically analyzing the combination data of concentration drop and solution stable duration in historical production, and determining the risk critical distance that can effectively distinguish between intervention and emergency treatment.

[0087] If the distance value exceeds the preset far-end reference distance, the emergency level response is triggered.

[0088] The intervention level response and the emergency level response are mapped to the sedimentation risk assessment result.

[0089] The reason for monitoring the decrease in concentration after solvent replenishment is that adding solvent increases the total amount of solvent in the immersion solution. If the solute is not replenished simultaneously during the solvent replenishment process, the solute content per unit volume or mass of the immersion solution will decrease, resulting in a decrease in concentration. By recording the concentration before and after solvent replenishment and calculating the difference between the two, we can quantify the absolute concentration difference, which provides a basis for subsequent assessment of precipitation risk.

[0090] The concentration dynamic compensation module is linked to the stirrer for stirring during the production interval according to the anti-precipitation instruction, and solute is injected synchronously until the concentration of the impregnation liquid reaches the standard.

[0091] join Figure 3 As shown, the specific steps of linking the agitator to stir during the production interval according to the anti-sedimentation instruction are as follows: real-time monitoring of the paper running position sensor signal, and generating a production interval mark when it is detected that the paper is completely out of the dipping tank.

[0092] Specifically, position sensors, such as photoelectric sensors or infrared sensors, are installed at the paper entrance and exit of the immersion tank to monitor the running position of the paper in real time. The sensors continuously collect paper position signals. When it is detected that the end of the paper has completely passed through the exit sensor, it is determined that the paper is completely out of the immersion tank. Once it is confirmed that the paper is completely out of the tank, a production break mark is immediately generated.

[0093] Receive the sedimentation risk assessment result, activate the enhanced stirring mode if it is an emergency level response, and activate the standard stirring mode if it is an intervention level response.

[0094] The stirring enable command is output only when the production break mark and the stirring mode activation signal exist at the same time.

[0095] When the stirring enable instruction is the enhanced stirring mode, the stirrer is driven to run at a preset maximum speed; when the stirring enable instruction is the standard stirring mode, the stirrer is driven to run at a preset reference speed.

[0096] It should be noted that the preset maximum speed is to deal with emergency-level precipitation risks and is usually determined based on the equipment's rated speed range and the critical speed for quickly eliminating precipitation during process verification.

[0097] The preset benchmark speed is aimed at intervention-level precipitation risks. It is based on the conventional effective stirring speed that can maintain solution stability and avoid precipitation formation in normal historical production. The benchmark value is determined after long-term process data statistics and experimental optimization to balance the stirring effect and energy consumption.

[0098] The specific steps of injecting solute until the concentration of the immersion liquid meets the standard are as follows: when the stirring mode is the enhanced stirring mode, the solute injection flow rate is set to the preset high speed gear; when the stirring mode is the standard stirring mode, the solute injection flow rate is set to the preset base gear.

[0099] It should be noted that the preset high speed and the preset reference are usually determined based on the process data of the solute injection effect under different stirring modes in historical production. The influence of different flow rates on the concentration compensation efficiency and stability is verified by experiments, and finally the flow rate value that can quickly reach the standard and does not cause over-compensation is pre-stored in the system as the solute injection flow rate standard corresponding to the stirring mode. For example, if the preset reference is 5L / min, the concentration can be smoothly compensated to the target value, and the preset high speed can be set to 15L / min to increase the concentration to match the mixing efficiency of high-intensity stirring at a faster speed.

[0100] The current concentration value is compared with the target concentration threshold in real time. If the current concentration continues to be lower than the target concentration threshold, the injection is maintained. If the current concentration first reaches the target concentration threshold, the standard reaching and stabilizing timing is started.

[0101] It should be noted that the target concentration threshold is determined based on the quality requirements of the impregnation paper production process on the concentration of the impregnation liquid, and is usually retrieved from the pre-stored process parameter library to ensure that the impregnation effect of the paper, such as impregnation uniformity and impregnation amount, meets the standard.

[0102] When the current concentration exceeds the target concentration threshold and the standard reaching and stabilizing timing exceeds the preset holding time length at the same time, the injection valve is closed.

[0103] Specifically, the actual stabilizing time length after each concentration reaches the standard is recorded, and the optimal holding time length under different working conditions is dynamically updated, so that the preset value gradually approaches the real demand for concentration stabilization in actual production.

[0104] If the injection duration exceeds the maximum allowed injection time length, the injection is immediately terminated and an over-injection alarm is triggered.

[0105] The above-mentioned maximum allowed injection time length is usually determined based on process parameters such as solubility of the solute of the impregnation liquid, target concentration threshold, and solute injection flow rate, combined with safe and effective injection time length data in historical production, and pre-stored in the process parameter library after experimental verification.

[0106] The quality inspection early warning intervention module records the water level adjustment time length, the concentration compensation time length, and the instruction response time length. When any of the time lengths exceeds the corresponding process window, an impregnation process abnormality alarm is triggered, and a reset instruction is output to the corresponding adjustment module.

[0107] It should be noted that the above-mentioned water level adjustment time length refers to starting the timing when the dynamic pressure deviation exceeds the tolerance, and stopping the timing when the liquid level change rate is stable.

[0108] The concentration compensation time length refers to starting the timing when the anti-deposition instruction is triggered, and stopping the timing when the solute injection is stopped and the concentration reaches the standard.

[0109] The instruction response duration refers to starting the corresponding timing when the liquid supplement valve adjustment, anti-precipitation or solute injection instruction is issued, and stopping the timing when the execution completion feedback is received.

[0110] The specific content of the trigger immersion process abnormality alarm is as follows: when a single duration timeout and no associated abnormality is triggered, a blue warning light is constantly driven, and a buzzer performs low-frequency intermittent buzzing.

[0111] It should be noted that the water level adjustment duration exceeding the maximum duration for completing a water level calibration is recorded as water level adjustment duration timeout, the concentration compensation duration exceeding the maximum duration for completing a concentration calibration is recorded as concentration compensation duration timeout, and the instruction response duration exceeding the maximum duration from the issuance of the instruction to the execution of the instruction by the corresponding module and the feedback of the result is recorded as instruction response duration timeout.

[0112] The single duration timeout can be any one of the above water level adjustment duration timeout, concentration compensation duration timeout and instruction response duration timeout.

[0113] When two durations timeout at the same time or a single module timeout triggers concentration precipitation linkage module risk escalation, a yellow warning light is driven to flash, and a buzzer is switched to continuous buzzing.

[0114] When three durations timeout at the same time or trigger concentration precipitation linkage module emergency level response, a red warning light is driven to flash at high speed, and a buzzer continuously buzzes.

[0115] The specific content of the output interrupt reset instruction to the corresponding adjustment module is as follows: when the water level adjustment duration timeout triggers the reset, a liquid supplement valve forced zero reset instruction is sent to the water level adjustment module, a dynamic pressure calibration module is activated to perform a liquid level reference zero point verification, and the reset is released after the pressure sensitive film sensor array feedback pressure stability signal.

[0116] When the concentration compensation duration timeout triggers the reset, a solute injection valve emergency closing instruction is sent to the concentration dynamic compensation module, and the concentration precipitation linkage module re-evaluates the precipitation risk level, and the reset is released after the solution stability duration returns to the dynamic qualified domain boundary.

[0117] When the instruction response duration timeout triggers the reset, a parameter initialization instruction is sent to the dynamic pressure calibration module and the water level adjustment step, the data synchronization protocol of the pressure sensitive film sensor array and the ultrasonic liquid level sensor is restarted, and the reset is released after the dynamic pressure deviation is within the tolerance range for a plurality of consecutive sampling periods.

[0118] The above embodiments can be realized all or partially by software, hardware, firmware or any other combination. When realized by software, the above embodiments can be realized all or partially in the form of a computer program product.

[0119] Those skilled in the art can understand that the modules and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0120] In addition, each functional module in each embodiment of the present application can be integrated in one processing module, or each module can exist physically alone, or two or more modules can be integrated in one module.

[0121] The above is merely specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any skilled in the art within the technical scope disclosed in the present application can easily think of changes or replacements, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0122] Finally, the above is only the preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A quality inspection and early warning system for impregnated paper production, characterized by: include: The immersion parameter acquisition module is used to collect the liquid level of the immersion tank and the liquid pressure of the paper immersion area in real time; Dynamic pressure calibration module, used to calculate the theoretical pressure of the paper at the current immersion depth based on the real-time liquid level height and the density of the immersion liquid, and generate the dynamic pressure deviation between the liquid pressure and the theoretical pressure; The water level intelligent adjustment module is used to drive the opening adjustment of the liquid filling valve through a dynamic mechanism when the dynamic pressure deviation exceeds the tolerance range, and to correct the solvent flow rate according to the rate of change of the liquid level; The concentration-precipitation linkage module is used to detect the concentration drop after solvent replenishment, evaluate the precipitation risk by analyzing the concentration drop and the solution stability time, and trigger the anti-precipitation instruction when the risk reaches the activation condition; The concentration dynamic compensation module is used to control the agitator during production intervals according to the anti-sedimentation instruction and to inject solutes synchronously until the concentration of the impregnation liquid reaches the standard; The quality inspection early warning intervention module is used to record the water level adjustment time, concentration compensation time and instruction response time. When any time exceeds the corresponding process time window, an abnormal alarm of the immersion process is triggered and an interrupt reset instruction is output to the corresponding adjustment module.

2. A quality inspection and early warning system for impregnated paper production according to claim 1, characterized in that: The specific contents of the impregnation parameter acquisition module are as follows: In the immersion tank, multiple sets of miniature ultrasonic level sensors are embedded along the length of the tank wall on the top of both sides of the tank, which are parallel to the paper running track. The transmitting ends of all sensors are covered with a layer of hydrophobic ultrasonic transmitting material and are installed downward perpendicular to the liquid surface. According to the preset width of the paper immersion area, the ultrasonic liquid level sensor at the corresponding position in the area is activated to output the measured value of the immersion tank liquid level in real time; A distributed pressure-sensitive film sensor array is embedded on a plane at the bottom of the immersion tank corresponding to the area where the paper is immersed; Read the pressure data detected by the pressure-sensitive film sensor array in real time, and output the original value of the liquid pressure in the paper immersion area after denoising; When the paper running position deviates, the pressure-sensitive film sensors outside the original immersed area are turned off, and the corresponding sensors in the new covered area are activated.

3. The quality inspection and early warning system for impregnated paper production according to claim 1, characterized in that: The specific contents of calculating the theoretical pressure of the current immersion depth of the paper based on the real-time liquid level height and the density of the immersion liquid are as follows: Taking the liquid level height in the immersion tank under no-load condition as the zero point reference, establish the absolute coordinate system of liquid level height; According to the real-time liquid level height and the fixed installation height of the paper in the immersion tank, the vertical distance between the lower surface of the paper and the current liquid surface is dynamically calculated as the real-time immersion depth; Calling the calibrated density value corresponding to the current impregnation liquid from the pre-stored process parameter library; Input the real-time immersion depth and the calibrated density value into the fluid statics relationship and output the theoretical pressure value corresponding to the current immersion depth of the paper; The liquid pressure is instantaneously compared with the theoretical pressure value to generate a dynamic pressure deviation signal of the difference between the two.

4. The quality inspection and early warning system for impregnated paper production according to claim 1, characterized in that: The specific steps of the water level intelligent adjustment module are as follows: When a dynamic pressure deviation signal is received, verifying that the signal exceeds a tolerance range for a predetermined time step and reaches a minimum response threshold; During the period of out-of-tolerance, the polarity change of the dynamic pressure deviation for several consecutive sampling cycles is detected in real time. If the polarity is consistent, a unidirectional evolution flag is output; if the polarity is alternating, an oscillating evolution flag is output; Calculate the ratio of the range of dynamic pressure deviation to the time span in the current time window, map it to the predefined rate level table and output the rate level code; Combining the unidirectional evolution sign or the oscillatory evolution sign with the rate level code into the deviation evolution characteristic value; Matching the corresponding reference valve opening value from a preset opening adjustment mapping table according to the deviation evolution characteristic value; If the liquid level height change rate is positive and exceeds the threshold reference opening value, the fixed compensation amount is adjusted downward; if the liquid level height change rate is negative and exceeds the threshold reference opening value, the fixed compensation amount is adjusted upward; Convert the compensated opening value into the valve opening instruction.

5. The quality inspection and early warning system for impregnated paper production according to claim 1, characterized in that: The specific steps of detecting the concentration drop after the solvent is added are as follows: When the valve opening instruction changes from zero to non-zero, the concentration of the immersion liquid at this moment is recorded as the reference concentration value; After monitoring the opening of the refill valve and returning to zero, the first delay timing is started and the current concentration is recorded as the end concentration value at the end of the delay; The absolute concentration difference is obtained by subtracting the reference concentration value from the end concentration value; If the absolute concentration difference exceeds the preset minimum effective drop threshold, an effective drop signal is marked; If the concentration monitoring interruption duration during the rehydration period is less than the maximum permissible interruption threshold, the data complete signal is marked; When both the effective decrease signal and the data complete signal are received, the absolute concentration difference is output as the concentration decrease amplitude.

6. The quality inspection and early warning system for impregnated paper production according to claim 1, characterized in that: The specific contents of analyzing the concentration drop and solution stability time to evaluate the precipitation risk are as follows: Based on historical normal production data, a curve showing the relationship between concentration reduction and stable duration is established, and the dynamic qualified domain boundary of the current production cycle is output; The concentration drop and the measured solution stability time are combined into a two-dimensional coordinate point; If the coordinate point is within the boundary of the dynamic qualified domain, a risk-free indicator is output; if the coordinate point is outside the boundary of the dynamic qualified domain, a sedimentation risk indicator is output; Obtain the minimum geometric distance value of the coordinate point deviating from the boundary of the dynamic qualified domain. If the distance value does not exceed the preset proximal reference distance, an observation-level response is triggered. If the distance value exceeds the preset near-end reference distance but does not exceed the preset far-end reference distance, an intervention-level response is triggered; If the distance value exceeds the preset remote reference distance, an emergency response is triggered; Map intervention-level responses and emergency-level responses to sedimentation risk assessment results.

7. A quality inspection and early warning system for impregnated paper production according to claim 6, characterized in that: The specific contents of the said stirring by the agitator during the production interval according to the anti-sedimentation instruction are as follows: Real-time monitoring of the paper running position sensor signal, when it is detected that the paper is completely out of the impregnation tank, a production break mark is generated; Receive sedimentation risk assessment results, activate enhanced stirring mode if the response is emergency level, and activate standard stirring mode if the response is intervention level; The stirring enable command is output only when both the production break mark and the stirring mode activation signal are present; When the stirring enable instruction is the enhanced stirring mode, the stirrer is driven to run at a preset maximum speed; when the stirring enable instruction is the standard stirring mode, the stirrer is driven to run at a preset reference speed.

8. The quality inspection and early warning system for impregnated paper production according to claim 7, characterized in that: The specific steps of injecting solute until the concentration of the impregnation solution reaches the standard are as follows: When the stirring mode is the enhanced stirring mode, the solute injection flow rate is set to the preset high speed gear; when the stirring mode is the standard stirring mode, the solute injection flow rate is set to the preset base gear; Compare the current concentration value with the target concentration threshold in real time. If the current concentration continues to be lower than the target concentration threshold, the injection is maintained. If the current concentration reaches the target concentration threshold for the first time, the target stabilization timer is started. When the current concentration exceeds the target concentration threshold and the target stability timer exceeds the preset holding time, the injection valve is closed; If the injection duration exceeds the maximum allowable injection time, the injection will be terminated immediately and an over-injection alarm will be triggered.

9. The quality inspection and early warning system for impregnated paper production according to claim 1, characterized in that: The specific contents of triggering the abnormal alarm of the dipping process are as follows: When a single time duration times out and no associated exception is caused, the blue warning light will be on and the buzzer will sound intermittently at a low frequency. When both time periods expire at the same time or a single module times out, causing the concentration precipitation linkage module risk to escalate, the yellow warning light will flash and the buzzer will switch to continuous sounding; When the three time periods expire at the same time or the concentration precipitation linkage module triggers an emergency response, the red warning light will flash at high speed and the buzzer will sound continuously.

10. The quality inspection and early warning system for impregnated paper production according to claim 1, characterized in that: The specific content of outputting the interrupt reset instruction to the corresponding adjustment module is as follows: When the water level adjustment time is exceeded and a reset is triggered, a forced zero return instruction of the liquid filling valve is sent to the water level adjustment module, and the dynamic pressure calibration module is activated to perform a liquid level reference zero point calibration. The reset is released after the pressure sensitive film sensor array feedbacks a pressure stabilization signal. When the concentration compensation timeout triggers a reset, a solute injection valve emergency closure instruction is sent to the concentration dynamic compensation module, and the concentration precipitation linkage module is linked to re-evaluate the precipitation risk level. The reset is released after the solution stabilization time returns to the dynamic qualified domain boundary; When the command response timeout triggers a reset, a parameter initialization command is sent to the dynamic pressure calibration module and the water level adjustment step, and the data synchronization protocol between the pressure-sensitive film sensor array and the ultrasonic liquid level sensor is restarted. The reset is released after the dynamic pressure deviation is within the tolerance range for several consecutive sampling cycles.

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