Method and system for eggshell washing control based on multi-source perception

Abstract

The application discloses a method and system for eggshell washing control based on multi-source sensing, and belongs to the field of intelligent process control of food processing. Multi-source sensing data of temperature, spraying liquid force, spiral load, liquid discharge solid, and circulating water quality are collected to complete time sequence correlation and effectiveness test; the cumulative thermal effect of eggshell membrane is calculated in combination with material residence time to constrain the liquid force mechanical regulation in the membrane softening state; eggshell membrane fragments and calcium particles are identified and distinguished to establish a loss risk model to limit the spraying and spiral regulation range; a control domain is constructed according to the multi-state priority to output heating, spraying, conveying, and water supplement and discharge control amounts, and the parameters are corrected in a feedback closed loop relying on execution. The system comprises a spiral washing device, a gradient backwater device, a cyclone recovery device, and a multi-sensing controller. The application adopts hierarchical constraint process control, takes into account the membrane shell separation efficiency and calcium particle recovery, realizes hot water gradient reuse and equipment fault interlocking, and solves the problems of poor stripping effect and large calcium loss amount in traditional regulation and control.

Description

Technical Field

[0001] This invention relates to the field of food processing control technology, specifically to a method and system for controlling eggshell washing based on multi-source sensing. Background Technology

[0002] The eggshells produced during poultry egg processing contain calcium components that can be used for the preparation of bio-calcium in food, and the inner surface of the eggshell is covered with an organic membrane. Before the membrane-covered eggshell material enters the drying, crushing, or refining processes, it is necessary to reduce the content of the eggshell membrane and residual egg liquid.

[0003] Existing batch soaking, stirring, or manual rinsing processes are difficult to reliably integrate with continuous shell-breaking production lines. Insufficient mechanical action makes it difficult for the eggshell membrane to detach, while excessive mechanical action can lead to over-crushing of calcareous eggshell particles, which are then lost with the draining liquid. When using fixed water temperature, fixed spray flow rate, and fixed screw speed, changes in feed particle size, feed load, degree of slippage, and eggshell membrane adhesion state will alter the actual residence time and heating process of the membrane-coated eggshell material.

[0004] Increasing the spray pressure alone can enhance fluid shear, but it also increases the discharge carrying capacity; decreasing the screw speed alone can prolong the heating time, but it increases material accumulation and the risk of drive overload. The discharge contains both desired eggshell membrane fragments and recoverable calcium-rich eggshell particles; relying solely on the total solids content of the discharge cannot accurately reflect the loss of these particles. Fluctuations in circulating hot water quality, changes in pipe resistance caused by water path switching, and sensor malfunctions in high-humidity and vibration environments can also lead to spray instability and erroneous control. Therefore, a continuous washing collaborative control method and system is needed that can link the thermal effects of eggshell membranes, hydraulic-mechanical effects, calcium-rich eggshell particle loss, and circulating hot water status according to a causal relationship, and correct these factors through a closed-loop response. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-source sensing-based eggshell washing control method and system, which solves the technical problems in the continuous hot water spray washing process of membrane-coated eggshell materials, such as: single-point temperature cannot represent the actual cumulative heat effect; independent adjustment of spray shearing and spiral mechanical action can easily lead to insufficient membrane peeling or excessive breakage of calcium eggshell particles; total solids in the drain cannot distinguish between eggshell membrane fragments and calcium eggshell particles; and changes in the state of circulating hot water and abnormal sensor data can cause erroneous control.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A multi-source sensing-based eggshell washing control method is applied to the hot water spray washing and membrane separation process of membrane-coated eggshell materials, including the following steps:

[0008] Collect zoned hot water temperature data, spray hydraulic status data, screw drive load data, discharged solids status data, and circulating hot water status data; perform time correlation and validity verification on the multi-source sensing data to form effective multi-source sensing data.

[0009] The effective thermal state of the eggshell membrane is determined based on the effective zone hot water temperature data and the actual residence time of the membrane-covered eggshell material in each spray zone.

[0010] After the eggshell membrane reaches the softening condition under effective thermal action, the hydraulic-mechanical coordination state is determined based on the effective spray hydraulic state data and the effective screw drive load data.

[0011] Identify calcium-rich eggshell particles from effective drainage solid state data, determine the risk of calcium-rich eggshell particle loss based on the state of the calcium-rich eggshell particles and the drainage flow rate, and determine the availability of circulating hot water based on effective circulating hot water state data.

[0012] The adjustment range of spray control and spiral conveying control is limited by the risk of calcium eggshell particle loss, and the direction of hydraulic-mechanical coordinated adjustment is limited by the effective thermal effect state of the eggshell membrane. The control quantities of heating, spraying, spiral conveying, water replenishment and drainage are generated in combination with the availability of circulating hot water. After the control quantities are executed, execution feedback and new multi-source sensing data are collected, and the control quantities are corrected according to the direction of change of the target state until the target state is continuously in the target range or the abnormal termination condition is triggered.

[0013] In addition, the present invention also discloses an eggshell washing control system based on multi-source sensing, which is used to execute the eggshell washing control method based on multi-source sensing as described above, including an inclined spiral conveying mechanism, a hot water spraying mechanism, a circulating hot water mechanism, a draining and sewage discharge mechanism, a cascaded recycling tank, a multi-source sensing module, a controller, and an actuator.

[0014] The inclined screw conveyor has a feed inlet, a top discharge outlet, and a drain outlet, with the drain outlet located at the lower end of the inclined screw conveyor.

[0015] The hot water spraying mechanism is arranged above the inclined spiral conveying mechanism along its axial direction, and includes a membrane softening spraying area, a peeling spraying area, and an end rinsing spraying area. Each spraying area is equipped with a nozzle and an independent regulating valve.

[0016] The circulating hot water mechanism includes a circulating water tank, a heater, a circulating water pump, and a filter. The circulating water pump delivers the hot water from the circulating water tank to each spray area of ​​the hot water spray mechanism after passing through the filter and the heater.

[0017] The liquid discharge and sewage discharge mechanism is located downstream of the liquid discharge and sewage discharge port, and the cascade recovery tank is located downstream of the liquid discharge and sewage discharge mechanism, used to receive the discharged liquid and separate and recover the solids;

[0018] The multi-source sensing module includes temperature sensors, pressure sensors, flow sensors, current detection units, torque detection units, speed detection units, drainage flow detection units, solid particle detection units, liquid level sensors, turbidity sensors, and conductivity sensors installed on various devices.

[0019] The actuator includes a heater, a circulating water pump, independent regulating valves for each spray zone, a screw drive motor, a water supply valve, and a drain valve.

[0020] The controller includes a processor and a memory. The memory stores a data validity verification program, a state determination program, an allowable control domain generation program, an execution control program, and a feedback correction program. The controller is communicatively connected to the multi-source sensing module and each actuator.

[0021] When the processor executes the program, the data validity verification program receives the output from the multi-source sensing module and outputs valid multi-source sensing data to the state determination program. The state determination program outputs the effective thermal state of the eggshell membrane, the hydraulic-mechanical coordination state, the risk of calcium eggshell particle loss, and the availability of circulating hot water. The allowable control domain generation program receives each state and outputs control quantities for heating, spraying, spiral conveying, water replenishment, and drainage. The execution control program sends the control quantities to the corresponding actuators. The feedback correction program receives feedback from the actuators and new multi-source sensing data and updates the data validity state and control quantities until the critical state is continuously within the target range or an abnormal termination condition is triggered.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] This invention determines the effective thermal state of the eggshell membrane based on the zoned hot water temperature and actual residence time. It incorporates the influence of actual screw speed, feed load, material slippage, and spray zone length on the actual heating process, reducing the softening judgment bias caused by relying solely on single-point temperature. The effective thermal state of the eggshell membrane participates in control before the hydraulic-mechanical coordination state, ensuring that temperature or residence time is adjusted preferentially when membrane softening is insufficient, avoiding replacing thermal softening with increased spray shear. After classification and identification, the loss risk of discharged solids is only assessed based on the state of calcium eggshell particles, preventing the increase of eggshell membrane fragments from being misjudged as calcium eggshell particle loss. The risk of calcium eggshell particle loss limits the adjustment range of spray and screw conveying, coordinating membrane peeling and calcium eggshell particle recovery within the same permissible control domain. The results of the execution feedback and physical response correlation are re-entered into data validity verification and the next washing control cycle, distinguishing between actuator malfunctions, sensor channel abnormalities, and process disturbances. Before switching the hot water cascade reuse path, the pumps and valves are pre-adjusted. After the switch, the hydraulic status is confirmed based on the pressure and flow rate, which helps to reduce spray fluctuations and reduce the consumption of fresh water per unit mass. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is the main flowchart of the eggshell washing control method based on multi-source sensing of the present invention.

[0026] Figure 2 This is a detailed flowchart of the multi-source sensing data acquisition and validity verification process of the present invention.

[0027] Figure 3 This is a flowchart illustrating the determination of the effective thermal state of the eggshell membrane in this invention.

[0028] Figure 4 This is a block diagram of the architecture of the eggshell washing control system based on multi-source sensing of the present invention. Detailed Implementation

[0029] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0030] The following is in conjunction with the appendix Figures 1-4 The embodiments of the present invention will be described in detail below.

[0031] In this invention, the membrane-covered eggshell material is the membrane-covered shell formed after the egg is cracked and liquid is extracted, or membrane-covered shell flakes formed after preliminary crushing. Before entering the inclined screw conveyor mechanism, the membrane-covered eggshell material can undergo dewatering, foreign matter removal, and particle size control. The inclined screw conveyor mechanism uses screw blades to push the membrane-covered eggshell material axially upwards along the outer cylinder, while the inclined setting of the outer cylinder causes the washing water to flow downwards under the action of gravity.

[0032] The hot water spraying mechanism is arranged axially along the inclined spiral conveyor. The hot water spraying mechanism includes a membrane softening spraying area, a peeling spraying area, and a final rinsing spraying area. The membrane softening spraying area provides uniform heat to the membrane-coated eggshell material; the peeling spraying area provides fluid shear after the eggshell membrane has softened; and the final rinsing spraying area reduces eggshell membrane fragments and residual washing liquid on the surface of the calcareous eggshell particles.

[0033] As the spiral blades propel the membrane-covered eggshell material towards the upper end, the material tumbles, slides, and rubs against each other between adjacent blades. Hot water is sprayed and converged from the upper end to the lower end, causing the conveying direction of the membrane-covered eggshell material to be opposite to the overall flow direction of the hot water. The resulting eggshell membrane fragments are discharged towards the lower end with the washing water, while the calcareous eggshell particles continue to move towards the top discharge port, propelled by the spiral blades.

[0034] The controller integrates sensor data processing, state determination, permissible control domain generation, execution control, and feedback correction into a closed loop. The effective thermal state of the eggshell membrane is not an independent output, but rather a prerequisite constraint for determining the hydraulic-mechanical coordinated state and generating control quantities. The risk of calcium eggshell particle loss is not simply an alarm result, but is transformed into the upper limit of the spray control quantity and the permissible range of the spiral conveyor control quantity. The actuator response is not merely for recording, but is fed back to verify the validity of multi-source sensor data and for the next washing control cycle.

[0035] The specific steps are as follows:

[0036] Step S1: Equipment startup, material conveying, and multi-source sensing data acquisition;

[0037] The inclined screw conveyor mechanism includes an outer cylinder, screw blades, a screw drive motor, a feed inlet, a top discharge outlet, and a drain outlet. The outer cylinder is inclined relative to the horizontal plane. The screw blades can be continuous, segmented, or have a smooth turning mechanism. A rotation gap is maintained between the outer edge of the screw blades and the inner wall of the outer cylinder, and the rotation gap is determined according to the particle size of the calcium-rich eggshell particles to be recovered.

[0038] When the controller starts, it checks the circulating water tank level, circulating water pump status, heater status, independent regulating valve position, screw drive motor status, drain channel status, and sensor communication status. If the circulating water tank level is lower than the starting level, the water supply valve opens. Once the circulating water tank level reaches the starting condition, the controller starts the circulating water pump, allowing the circulating hot water to pass through the filter and heater before entering the hot water spray mechanism.

[0039] Once the temperatures in multiple spray zones reach the allowable starting range, the controller initiates no-load operation of the inclined screw conveyor. During no-load operation, the screw drive current, screw drive output torque, and actual screw speed are collected. Feeding of eggshell material with film is permitted when the no-load data is within the equipment's allowable range.

[0040] The multi-source sensing module collects the following data: temperature of the circulating water tank, heater outlet, membrane softening spray area, stripping spray area, end rinsing spray area, and return water pipeline; spray pressure and spray flow rate of the circulating water pump outlet, main water supply pipe, and zoned water supply branches; screw drive current, screw drive output torque, screw set speed, and actual screw speed; discharge flow rate and images or online screening detection results of solid particles in the discharge; circulating water tank level, circulating water turbidity, circulating water conductivity, and circulating water temperature; feed load, feed particle size distribution, and continuous discharge status of calcium eggshell particles.

[0041] The sampling period is determined based on the response speed of the physical object. Temperature data changes less rapidly than pressure, flow rate, and drive load data; therefore, a 1-second sampling period can be used for temperature sensors, while a 0.2-second sampling period can be used for pressure sensors, flow sensors, current detection units, torque detection units, and speed detection units. A 0.5-second sampling period can be used for liquid solid state data, and a 5-second sampling period can be used for turbidity and conductivity data. The actual sampling period is calibrated based on the sensor response time and the equipment control cycle.

[0042] For example, when the washing control cycle is set to 1 second, five sets of spray pressure data are obtained within one washing control cycle. The five sets of spray pressures are 0.24 MPa, 0.25 MPa, 0.26 MPa, 0.25 MPa, and 0.25 MPa, respectively. After all five sets of data pass the validity test, the cycle-averaged spray pressure is 0.25 MPa. The cycle-averaged spray pressure is then used to determine the subsequent spray hydraulic action state.

[0043] Step S2: Verification of the validity of time-related and multi-source sensing data;

[0044] The controller unifies multi-source sensing data from different sampling periods into a single washing control cycle. Rapidly changing data is represented by periodic averages, periodic peak values, or periodic trend data, while slowly changing data is represented by the most recent valid value. The discharged solids image uses statistical results of particle number, particle size distribution, and category within the washing control cycle.

[0045] Range testing is used to determine whether the sensor data is within the sensor's range and the physical limits allowed by the equipment. For temperature sensors with a range of 0℃ to 100℃, temperature data exceeding this range will not be included in the calculation. When pressure data exceeds the rated pressure of the water supply pipeline, not only is the pressure data flagged as abnormal, but pressure protection is also triggered.

[0046] The rate of change test is used to determine whether the data change in adjacent washing control cycles exceeds the maximum change the equipment can produce. The allowable rate of change is determined by the heater's rated power, circulating water volume, circulating water pump acceleration capability, valve action time, and screw drive motor acceleration and deceleration time. The continuous invariance test is used to identify sensor jamming or communication freeze. If, after an actuator performs an action that causes a change in a physical quantity, the corresponding sensor data remains completely unchanged within the allowable response time, the controller marks the corresponding data channel as continuously invariant. The allowable response time is preset based on the dynamic characteristics of the actuator and sensor.

[0047] The physical response correlation consistency test links control commands, execution feedback, and physical quantity responses. When heater power increases, the circulating water tank temperature or heater outlet temperature should rise within the allowable time of thermal inertia. When the circulating water pump output increases, the spray pressure or spray flow rate should change. When the opening of the independent regulating valve increases, the flow rate in the corresponding spray area should increase. When the set screw speed changes, the actual screw speed and screw drive current should produce corresponding responses.

[0048] For example, if the actual speed of the circulating water pump increases from 60% to 70% of the rated speed, the flow rate of the main water supply pipe increases from 1.62 m³ / h to 1.75 m³ / h, and the pressure of the main water supply pipe increases from 0.23 MPa to 0.25 MPa, and both the flow rate and pressure change in the expected direction within the set hydraulic response time, the controller will determine that the circulating water pump execution feedback, pressure data, and flow rate data are consistent with each other.

[0049] If the actual speed of the circulating water pump has increased while the pressure and flow rate remain unchanged, the controller will not immediately continue to increase the pump output. Instead, it will check the pump feedback, valve status, pipeline blockage, and sensor status. If the actual speed of the circulating water pump has not increased, the controller determines that the actuator is not responding. If the actual speed of the circulating water pump has increased while the pressure data changes but the flow data remains unchanged, the controller will list the flow sensor or flow channel as an anomaly candidate.

[0050] When a single non-critical data point is invalid, the controller can maintain a limited cycle using the most recent valid value, or freeze the state dependent on the corresponding data and limit the range of control variable changes. When both critical temperature data and actual rotational speed data are invalid, the controller stops feeding the membrane-coated eggshell material and enters a limited operating state. When the low liquid level data in the circulating water tank is invalid and the water supply condition cannot be confirmed through redundant signals, the controller stops the heater and circulating water pump.

[0051] Step S3: Determine the effective thermal state of the eggshell membrane;

[0052] The effective thermal effect state of the eggshell membrane reflects the cumulative degree to which the membrane-covered eggshell material receives hot water treatment in multiple spray zones. Inputs to the effective thermal effect state include the effective spray temperature of each spray zone, the axial length of each spray zone, the actual screw speed, the current feed load, and the feed particle size distribution. The particle size distribution is pre-defined based on the crushing and screening specifications of the membrane-covered eggshell raw material.

[0053] The actual axial conveying speed is not directly calculated as the theoretical product of the screw pitch and the screw speed. Due to slippage, tumbling, and falling of the eggshell material with film between the screw blades, the actual axial conveying speed needs to be obtained through calibration. During calibration, calcium-based eggshell particles with identification tags are introduced under no-load and different feed loads. The time it takes for the identification tags to pass through adjacent detection positions is recorded, forming a calibration data table relating the actual screw speed, feed load, and actual axial conveying speed.

[0054] The controller queries the calibration data table based on the current actual screw speed and current feed load to obtain the actual axial conveying speed corresponding to each spray zone. The axial length of the spray zone and the actual axial conveying speed together determine the actual residence time of the eggshell material with film within the spray zone. The effective heat transfer of the eggshell film is determined according to the following formula:

[0055]

[0056] in, The effective heat transfer of the eggshell membrane is expressed in °C·s. This represents the number of spray areas, and its value is a positive integer. This is the spray zone number, with values ​​ranging from 1 to... Positive integers; For the first The effective spray temperature of each spray zone is expressed in °C. The reference temperature for softening the eggshell membrane is given in °C. For membrane-bound eggshell material in the first The actual residence time within each spray zone is expressed in seconds.

[0057] When the effective spray temperature in the spraying area is lower than the eggshell membrane softening reference temperature, the corresponding temperature difference is treated as zero, and no negative heat contribution is generated. The eggshell membrane softening reference temperature is determined through heat treatment calibration of the same batch of membrane-bearing eggshell material. The calibration process involves treating membrane-bearing eggshell material at different water temperatures and treatment times, and detecting the residual eggshell membrane per unit area, peeling resistance, and the breakage state of calcareous eggshell particles. The lowest temperature corresponding to a continuous decrease in residual eggshell membrane and calcareous eggshell particle breakage within the allowable range can be used as the eggshell membrane softening reference temperature.

[0058] The target heat treatment zone is jointly defined based on the eggshell membrane residue rate and the calcium-rich eggshell particle recovery rate. Heat treatment conditions that only meet the eggshell membrane residue rate requirement but not the calcium-rich eggshell particle recovery rate requirement will not be included in the target heat treatment zone.

[0059] For example, the effective axial lengths of the membrane softening spray zone, the peeling spray zone, and the final rinsing spray zone are 1.2 m, 1.4 m, and 0.8 m, respectively. The actual axial conveying speeds given in the calibration data sheet are 0.015 m / s, 0.018 m / s, and 0.02 m / s, respectively, corresponding to actual residence times of 80 s, approximately 77.8 s, and 40 s. The effective spray temperatures of the three spray zones are 62℃, 63℃, and 61.5℃, respectively. When the eggshell membrane softening reference temperature is 55℃, the thermal contributions of the three zones are 560 ℃·s, 622.4 ℃·s, and 260 ℃·s, respectively, and the effective thermal effect of the eggshell membrane is 1442.2 ℃·s. When the effective thermal effect of the eggshell membrane is lower than the lower limit of the target thermal effect range, the controller enters a state of insufficient thermal effect.

[0060] When thermal effect is insufficient, the controller prioritizes checking the heater's allowable power and the circulating hot water temperature. If there is still room for temperature increase, the heater power is increased; if the temperature approaches the equipment's upper limit, the actual screw speed or feed rate is reduced. When the risk of calcium-rich eggshell particle loss is close to the upper limit, insufficient thermal effect is not compensated for by increasing the spray flow rate near the drainage and sludge discharge mechanism.

[0061] When the effective heat output of the eggshell membrane is within the target heat output range, the controller establishes a normal heat output state. When the effective heat output of the eggshell membrane exceeds the upper limit of the target heat output range, the controller establishes an excessive heat output state and, without causing material accumulation, increases the actual screw speed, reduces the heater power, or reduces the flow rate in the membrane softening spray zone.

[0062] Changes in feed particle size are corrected by the target thermal effect range, not by amplifying the current thermal effect evaluation value. When the average particle size and the highest quantile particle size increase, the controller activates a higher target thermal effect range or a longer allowable residence time; when the average particle size and the highest quantile particle size decrease, the controller activates a lower target thermal effect range. The aforementioned processing maintains consistency between the evaluation direction and the control direction.

[0063] Step S4: Identification of the type of excreted solids and determination of the risk of loss of calcium-rich eggshell particles;

[0064] The solids in the drained liquid include at least eggshell membrane fragments and calcareous eggshell particles. Eggshell membrane fragments are the materials that need to be discharged during the membrane-shell separation process, while calcareous eggshell particles are materials that need to be recovered. The controller does not use the total solids concentration of the drained liquid, directly creating a risk of loss. The solid particle detection unit can employ an image detection structure or an online sieving and weighing structure. The image detection structure is positioned above a transparent drain pipe section or an open drain tank, acquiring images of the drained solids and extracting the particle's projected area, equivalent diameter, aspect ratio, edge thickness, and velocity. Eggshell membrane fragments are typically thin sheets with a large aspect ratio and small edge thickness, moving at a velocity close to that of water flow. Calcium-rich eggshell particles have a large edge thickness and a high tendency to settle.

[0065] The online sieving and weighing system retains solids from the liquid discharge according to different pore sizes, recording the retained mass of each particle size range per unit time. The sieving results can be used in conjunction with image recognition results to determine the concentration and particle size distribution of calcium-rich eggshell particles. The solid category threshold is calibrated by samples of eggshell membrane fragments and calcium-rich eggshell particles after manual sorting.

[0066] The risk of calcium loss from eggshell particles is determined using the following formula:

[0067]

[0068] in, Risk value for calcium loss from eggshell particles; Weighted by the concentration of calcium-rich eggshell particles; Weight of calcium-rich eggshell particle size; The weights are for the drainage flow rate, and the sum of the three weights is 1. Each weight has a value between 0 and 1. The concentration of calcium-rich eggshell particles identified in the current discharge is expressed in g / L. The values ​​are reference values ​​for the concentration of calcium-rich eggshell particles, in g / L. The particle size corresponds to 90% of the cumulative particle size distribution of the currently discharged liquid that is identified as calcium-rich eggshell particles, in mm; The allowable particle size of calcium-rich eggshell particles is given in mm. This represents the current drainage flow rate, in m³ / h. This is a reference value for the drainage flow rate, in m³ / h.

[0069] Weights and reference values ​​are determined through drainage collection calibration. During calibration, drainage solids are collected within a set time window to separate eggshell membrane fragments and calcium-rich eggshell particles. The calcium-rich eggshell particles are dried and weighed, and compared with the corresponding dry mass of calcium-rich eggshell particles in the feed. The concentration, particle size, and drainage flow rate at which calcium-rich eggshell particle loss reaches the upper limit are used to determine reference values ​​and risk ranges.

[0070] For example, if the concentration of calcium-containing eggshell particles is 0.32 g / L, the reference value for calcium-containing eggshell particle concentration is 0.5 g / L, the high-resolution particle size of calcium-containing eggshell particles is 1.8 mm, the reference particle size is 2.5 mm, the current drainage flow rate is 1.7 m³ / h, and the reference drainage flow rate is 1.8 m³ / h, with the three weights being 0.45, 0.35, and 0.2 respectively, the three risk contributions are 0.288, 0.252, and approximately 0.189 respectively, and the risk value for calcium-containing eggshell particle loss is approximately 0.729.

[0071] When the risk of calcium eggshell particle loss enters the normal range, the hydraulic-mechanical coordination is allowed to adjust the spray and screw conveyor within the equipment's permissible range. When the risk of calcium eggshell particle loss enters the warning range, the controller limits the rate of increase of the spray control volume near the drainage and sewage discharge mechanism and increases the processing capacity of the solid recovery path. When the risk of calcium eggshell particle loss exceeds the limit, the controller prohibits further increasing the spray pressure or spray flow rate near the drainage and sewage discharge mechanism.

[0072] If the risk of calcium-rich eggshell particle loss exceeds the limit, the controller checks the effective thermal effect of the eggshell membrane. If the effective thermal effect of the eggshell membrane is insufficient, the controller prioritizes restoring softening conditions by increasing the allowable temperature or extending the residence time. If the effective thermal effect of the eggshell membrane is normal, the controller reduces the low-level spray flow rate or spray pressure and adjusts the upward conveying capacity within the allowable range of the screw drive load. If the risk continues to exceed the limit, the feed rate is reduced.

[0073] Step S5: Hydraulic-mechanical cooperative state and algorithm interaction;

[0074] The hydraulic-mechanical coordination state does not use a single linear summation of spray pressure, spray flow rate, and screw drive output torque. The controller separately determines the spray hydraulic action state and the screw mechanical action state.

[0075] The spray hydraulic operation state is determined based on the spray pressure, spray flow rate, actual circulating water pump speed, and actual opening degree of the independent regulating valve. Normal spray hydraulic operation occurs when both spray pressure and flow rate are within their respective target ranges. If the spray pressure is below the target range but the spray flow rate is normal, the controller checks for nozzle leakage, pipeline resistance, and pressure sensor issues. If the spray pressure is normal but the spray flow rate is insufficient, the controller checks for nozzle blockage and flow sensor issues.

[0076] The mechanical action state of the screw conveyor is determined based on the screw drive output torque, screw drive current, screw set speed, screw actual speed, and the continuity of calcium eggshell particle discharge. When the screw drive output torque increases, the actual screw speed stabilizes, and discharge is continuous, a state of enhanced mechanical action can be formed. When the screw drive output torque increases, the actual screw speed decreases, and the discharge rate decreases, a state of eggshell material accumulation with film or a state of mechanical stagnation of the inclined screw conveyor mechanism are candidate states. The algorithm for the effective thermal effect of the eggshell film and the algorithm for the hydraulic-mechanical cooperative state interact sequentially.

[0077] When the effective thermal effect on the eggshell membrane has not reached the softening condition, the hydraulic-mechanical cooperative state algorithm does not output the control direction for increasing the spray pressure in the peeling spray area. Only after the effective thermal effect on the eggshell membrane reaches the softening condition does the hydraulic-mechanical cooperative state algorithm determine the peeling control direction based on the spray hydraulic effect and the helical mechanical effect. The calcium eggshell particle loss risk algorithm interacts with the hydraulic-mechanical cooperative state algorithm according to a constraint relationship. The calcium eggshell particle loss risk algorithm outputs the upper limit of the spray control quantity and the allowable range of the helical conveying control quantity. The adjustment direction generated by the hydraulic-mechanical cooperative state algorithm must fall within the aforementioned range. When the hydraulic effect is insufficient but the calcium eggshell particle loss risk exceeds the limit, it is not allowed to continue increasing the low-level spray control quantity. The state combinations and control directions are shown in Table 1 below:

[0078] Table 1:

[0079] insufficient normal normal normal Increase the control level of the stripping spray area within the acceptable risk range. normal insufficient normal normal Reduce the actual screw speed or adjust the feed load within the allowable range of the drive load. insufficient insufficient insufficient normal Prioritize restoring the effective thermal state of the eggshell membrane, without directly enhancing the peeling spray. normal normal normal normal Maintain the current control level and proceed to feedback verification. Too high Normal or slightly elevated normal Warning or exceeding limits Reduce the low-level spray control volume and activate the solids recovery path. normal Torque increases and speed decreases any any Transition to identification of eggshell material accumulation state or mechanical hindrance state. insufficient normal insufficient Exceeding limits Increasing the allowable temperature or extending the residence time is prohibited; increasing the low-level spray flow rate is also prohibited.

[0080] For example, if the pressure in the peeling spray zone is below the target range, the spray flow rate is below the target range, the screw drive output torque is within the normal range, the eggshell membrane's effective thermal action has reached the softening condition, and the risk of calcium eggshell particle loss is within the normal range, the controller allows increasing the circulating water pump output or the opening of the independent regulating valve in the peeling spray zone. Under the same hydraulic conditions, if the risk of calcium eggshell particle loss exceeds the limit, the controller does not increase the spray control amount, but instead checks the nozzle direction, membrane softening condition, and feed load.

[0081] Step S6: Circulating hot water availability status and permissible control domain;

[0082] The circulating hot water system includes a circulating water tank, a heater, a circulating water pump, a filter, a water supply valve, and a drain valve. The availability of circulating hot water is determined based on the circulating water tank level, circulating water turbidity, circulating water conductivity, circulating water temperature, and the current water circuit connection status. The inlet water quality requirements include upper limits for turbidity and conductivity, which are determined by process water standards.

[0083] The heater must not operate when the circulating water tank level is lower than the heater's allowable operating level. The circulating water pump must be stopped if the inlet water supply conditions are insufficient. The water supply valve must be opened when the circulating water tank level is lower than the makeup water lower limit but higher than the safe shutdown level. The filter's operating intensity must be increased when the circulating water turbidity enters the filtration enhancement zone. Partial drainage and equal-volume makeup water must be performed when the circulating water turbidity exceeds the drainage threshold or the circulating water conductivity exceeds the soluble matter accumulation threshold.

[0084] For example, when the circulating water tank level is 68% of the effective volume, the circulating water turbidity is 110 NTU, the circulating water conductivity is 1.8 mS / cm, the level is within the normal range, the turbidity is within the enhanced filtration range, and the conductivity is below a certain drainage threshold, the controller keeps the water supply valve and drainage valve closed to increase the filter's operating intensity and continue to monitor changes in circulating water turbidity.

[0085] The controller forms an allowable control domain based on all states. Safety protection states have the highest priority. The effective status of multi-source sensing data determines whether each state can be updated. The state of eggshell material accumulation with membrane and the mechanical resistance state of the inclined screw conveyor take precedence over normal washing control. The risk of calcium eggshell particle loss limits the adjustment boundaries of spraying and screw conveying. The effective thermal effect status of the eggshell membrane limits the processing capacity and the direction of hydromechanical adjustment. The availability of circulating hot water determines the water source path and water replenishment / drainage control.

[0086] The heater power, circulating water pump output, independent regulating valve opening, and actual screw speed are all subject to rate-of-change limits. These rates are calibrated based on equipment rated parameters, circulating water thermal inertia, pipeline water hammer limits, and the accumulation state of the eggshell material with film. The permissible control domain provides not only the target control variable but also its upper and lower limits, permissible direction of change, and maximum change per cycle.

[0087] Step S7: Perform response, fault differentiation, and loop closure termination;

[0088] The controller sends hot water heating control signals to the heater, spray control signals to the circulating water pump and independent regulating valve, screw conveyor control signals to the screw drive motor, water replenishment control signals to the water replenishment valve, and drainage control signals to the drainage valve. After executing the control, the controller reads the heater's operating status, the actual speed of the circulating water pump, the actual opening degree of the independent regulating valve, the actual speed of the screw drive motor, the actual position of the water replenishment valve, and the actual position of the drainage valve. The controller also reads the corresponding temperature, pressure, flow rate, drive load, liquid level, and water quality response.

[0089] When the actuator has received the control command and completed its action, and the corresponding physical quantity changes in the expected direction within the allowed response time, the controller determines the actuator and data channel to be reliable. If the actuator has completed its action but the physical quantity has not changed, the controller checks for sensor and pipeline blockages and process load. If the actuator has not completed its action, the controller outputs actuator fault information and freezes the control quantities dependent on the corresponding actuator.

[0090] The accumulation state of eggshell material with film and the mechanical stagnation state of the inclined screw conveyor are distinguished by multiple signals. When the screw drive output torque increases, the actual screw speed remains basically constant, and the top discharge rate decreases but does not stop, the state of eggshell material accumulation with film is prioritized. The controller stops feeding, reduces the spray flow rate, and increases the screw conveying capacity within the allowable range of the equipment.

[0091] When the output torque and current of the screw drive increase simultaneously, the actual screw speed decreases significantly relative to the set screw speed, and the top discharge is interrupted, the inclined screw conveyor is determined to be in a mechanically stalled state. The controller stops the feeding of eggshell material with film and the hot water spraying, and controls the inclined screw conveyor to perform a stop, a short-term reverse, a stop again, and a resumption of forward rotation. The duration and speed of the short-term reverse are preset according to the characteristics of the screw drive motor and the material characteristics. After resuming forward rotation, the screw drive load data and the continuity of discharge are re-detected.

[0092] For example, if the screw speed is set to 12 r / min, and the actual screw speed drops to 8.5 r / min, the drive current rises to 13 A, the output torque enters the overload warning range, and the top discharge is interrupted, the controller enters the mechanical stagnation recovery process. After completing one short-term reverse rotation, when the actual screw speed recovers to 11.8 r / min, the drive current drops to the normal range, and the top discharge resumes, the controller gradually resumes spraying and feeding.

[0093] After each round of control quantity correction, the controller recalculates the effective thermal state of the eggshell membrane, the hydraulic-mechanical coordination state, the risk of calcium eggshell particle loss, and the availability of circulating hot water. If the critical state remains within the target range for three consecutive washing control cycles and the actuator responds normally, these three washing control cycles can be set as the normal stable termination condition. The number of consecutive cycles is calibrated based on process fluctuations and the control cycle. If the target state is not restored after three control quantity corrections, three corrections can be set as the maximum correction count, and the feed rate can be reduced. The controller terminates abnormally if the critical data combination is invalid, the actuator does not respond, mechanical blockage reaches the allowed number of recovery attempts but is not resolved, or safety protection is triggered. The aforementioned number of cycles and correction counts are equipment calibration parameters and are not limited to fixed values.

[0094] Step S8: Delay quality feedback and bounded parameter update;

[0095] Downstream of the top discharge port, there are detectors for eggshell membrane residue rate and calcium-rich eggshell particle recovery rate. The discharge quality detection has a conveying delay. The controller establishes a material time window mark for the membrane-covered eggshell material entering the inclined screw conveyor mechanism, and determines the time when the corresponding material reaches the top discharge port based on the actual axial conveying speed.

[0096] The output test results are correlated with the zoned hot water temperature, actual residence time, effective thermal effect state of the eggshell membrane, hydraulic-mechanical coordination state, and risk of calcium eggshell particle loss within the corresponding historical material time window. The current output quality does not directly correct the material parameters currently entering the equipment. The controller allows updates to the target thermal effect range only if both the eggshell membrane residue rate and the calcium eggshell particle recovery rate pass effectiveness testing, the deviation direction is consistent across multiple consecutive testing cycles, and no equipment malfunction occurs. The lower limit of the target thermal effect range is updated boundedly according to the following formula:

[0097]

[0098] in, The lower limit of the effective heat transfer of the updated eggshell membrane is given in °C·s. The lower limit of the effective heat transfer of the eggshell membrane before the update is given in °C·s. This is the calibration coefficient, with a value ranging from 0 to 1; The target is the eggshell membrane peeling rate; This represents the actual eggshell membrane peeling rate.

[0099] The calibration coefficient and the upper limit of a single update are determined through equipment commissioning. The updated target lower limit of thermal action needs to be verified against the allowable heater temperature, screw speed range, feed load range, and calcium eggshell particle recovery requirements. When the actual eggshell membrane peeling rate is lower than the target value, the target lower limit of thermal action is increased; when the actual eggshell membrane peeling rate is higher than the target value and the calcium eggshell particle recovery rate meets the requirements, the target lower limit of thermal action is allowed to be decreased; when the calcium eggshell particle recovery rate does not meet the requirements, it is prohibited to continue increasing the thermal or hydraulic mechanical action solely based on a higher eggshell membrane peeling rate. For example, if the target lower limit of thermal action before the update is 1350 ℃·s, the target eggshell membrane peeling rate is 93%, the actual eggshell membrane peeling rate is 89%, and the calibration coefficient is 0.3, the update ratio is approximately 1.29%, and the updated target lower limit of thermal action is approximately 1367.4 ℃·s. When the updated result is lower than the equipment's allowable upper limit and the calcium eggshell particle recovery rate meets the requirements, the updated result is used for subsequent material time windows.

[0100] To facilitate a better understanding of the present invention by those skilled in the art, the present invention will be further described below with reference to specific embodiments.

[0101] Example 1: In this example, the axial length of the outer cylinder of the inclined screw conveyor is 4.2 m, the inner diameter of the outer cylinder is 0.55 m, the inclination angle is 18°, and the screw blade pitch is 0.35 m. The screw drive motor adopts frequency conversion speed regulation, and the normal speed range is 8 r / min to 18 r / min. The processing capacity of eggshell material with membrane is set at 240 kg / h.

[0102] The hot water spray system has 12 nozzles, with 4 nozzles each for the membrane softening spray area, the peeling spray area, and the final rinsing spray area. The water supply temperature is set at 62.5℃, with an allowable control range of 60℃ to 65℃. The spray water supply pressure is set at 0.26 MPa, and the total spray flow rate is set at 1.8 m³ / h.

[0103] The temperature sensor uses a 1-second sampling period, the pressure, flow rate, current, torque, and speed use a 0.2-second sampling period, the discharged solid state data use a 0.5-second sampling period, and the circulating water turbidity and conductivity use a 5-second sampling period. The controller uses a 1-second washing control cycle.

[0104] The controller performs time correlation and validity checks on multi-source sensing data. The effective thermal state of the eggshell membrane is determined by verifying the zoned hot water temperature and actual residence time. The effective axial lengths of the membrane softening spray zone, peeling spray zone, and final rinsing spray zone are 1.2 m, 1.4 m, and 0.8 m, respectively. The calibration data table gives actual axial conveying speeds of 0.015 m / s, 0.018 m / s, and 0.02 m / s, corresponding to actual residence times of 80 s, approximately 77.8 s, and 40 s, respectively.

[0105] The effective spray temperatures in the three spray zones are 62℃, 63℃, and 61.5℃, respectively. The reference temperature for softening the eggshell membrane is 55℃, and the effective heat transfer to the eggshell membrane is 1442.2 ℃·s. When the target heat transfer range established by the equipment calibration is 1350 ℃·s to 1550 ℃·s, the controller achieves normal heat transfer status.

[0106] The solids detection system identified a calcium-rich eggshell particle concentration of 0.32 g / L, a high-resolution particle size of 1.8 mm, and a discharge flow rate of 1.7 m³ / h. Using corresponding reference values ​​and weights, the calculated risk value for calcium-rich eggshell particle loss was approximately 0.729, which is within the normal control range.

[0107] The eggshell membrane has reached the softening condition due to effective heat treatment, the risk of calcium loss from eggshell particles is within limits, the spray pressure and flow rate are within the target range, the screw drive output torque and actual screw speed are stable, and the controller has achieved a normal state of hydraulic-mechanical coordination. The controller maintains the control values ​​for heating, spraying, and screw conveying, and enters the execution response verification stage.

[0108] In a subsequent washing control cycle, the increased feed load led to a rise in the actual axial conveying speed, causing the effective heat transfer of the eggshell membrane to drop below the lower limit of the target heat transfer range. The circulating hot water temperature was 61℃, still with room for improvement. The controller prioritized increasing the heater power, without increasing the spray flow rate near the drain and sludge discharge mechanism. The heater was operating normally, and the heater outlet temperature rose as expected, returning the effective heat transfer of the eggshell membrane to the target range.

[0109] In another washing control cycle, the risk of calcium eggshell particle loss enters the warning range, and the hydraulic action in the stripping spray area is simultaneously low. The controller does not allow the hydraulic-mechanical coordination state to directly increase the low-level spray control quantity; instead, it reduces the feed rate, checks the nozzle direction, and increases the solid recovery path processing capacity. Only after the risk of calcium eggshell particle loss returns to the normal range does the controller allow spray adjustment to resume within a limited range. This embodiment forms a sequential interaction of the thermal action state algorithm, the calcium eggshell particle loss risk algorithm, and the hydraulic-mechanical coordination state algorithm.

[0110] Example 2: This example is a further optimization based on Example 1. The controller uses a combination of an industrial computer and a programmable logic controller (PLC). The industrial computer processes images of the discharged solids and records material time windows, while the PLC performs rapid data acquisition, interlock protection, and actuator control. The industrial computer and the PLC exchange calcium-containing eggshell particle identification results, status data, control limits, and fault information via an industrial communication network.

[0111] The solid image detection structure for the drained liquid is installed in the transparent drain pipe section. The structure acquires the projected area, equivalent diameter, aspect ratio, and edge thickness of the particles. Calibration samples include manually sorted eggshell membrane fragments and calcareous eggshell particles. The controller cross-validates the identification results with the retention quality of the online sieving structure. When the deviation between the two detection results exceeds the allowable range, the risk of frozen calcareous eggshell particle loss is updated and enters restricted control.

[0112] A particle size detection device is installed at the feed inlet. The average particle size and high-resolution particle size enter the preset particle size class. Larger particle size classes correspond to higher target thermal action ranges, and smaller particle size classes correspond to lower target thermal action ranges. A hysteresis condition is set for switching between target thermal action ranges to avoid frequent switching when particle size data fluctuates at adjacent class boundaries. The controller saves each control command and execution feedback. The heater power command corresponds to the heater's operating status, the circulating water pump speed command corresponds to the actual circulating water pump speed, the independent regulating valve opening command corresponds to the valve position feedback, and the screw speed command corresponds to the actual screw speed. If the actuator feedback is normal but the associated physical quantity does not change, the controller lists process blockage or sensor channel abnormality as candidate causes.

[0113] For example, the controller increases the opening of the independent regulating valve for the stripped-off sprinkler area from 45% to 52%. The valve actually opens to 52%, but the flow rate in the stripped-off sprinkler area remains unchanged, while the pressure in the main water supply pipe increases. The controller determines that the valve has responded, and the lack of flow increase may be caused by nozzle blockage or abnormal flow detection. The controller stops further increasing the valve opening and outputs inspection information.

[0114] When eggshell material with membrane is piled up, the controller stops feeding, reduces spray flow, and slowly increases screw conveyor capacity. When the inclined screw conveyor is mechanically blocked, the controller stops feeding and spraying, and performs a short-term reverse recovery. After the short-term reverse, when the load decreases and discharge resumes, the controller gradually resumes forward rotation, spraying, and feeding. If recovery is not achieved after the allowed number of recovery cycles, the machine stops. The material time window is established based on the time of entry into the equipment and the feed rate. The top discharge detection result is correlated to the historical material time window according to the actual conveying delay. An upper limit is set for the single update amplitude of the target thermal effect range, and the update result must simultaneously meet the constraints of eggshell membrane residue rate and calcium eggshell particle recovery rate.

[0115] Example 3: This example is based on the same principle as Example 1, except that the continuous washing and co-control system for eggshells with membranes is set between the shell breaking and liquid extraction process and the subsequent dehydration, drying and pulverization process in the food bio-calcium production line.

[0116] The membrane softening spray area, stripping spray area, and end-rinse spray area are each equipped with independent water supply branches, independent regulating valves, flow sensors, and temperature sensors. The end-rinse spray area uses hot water with high cleanliness requirements, the stripping spray area uses hot water with medium cleanliness requirements, and the membrane softening spray area is allowed to use filtered return water that meets the softening process requirements.

[0117] The controller detects the turbidity and conductivity of the return water from the end-rinse spray zone. If the return water from the end-rinse spray zone meets the influent water quality requirements of the stripping spray zone, it is redirected to the supply branch of the stripping spray zone. If the return water from the stripping spray zone meets the influent water quality requirements of the membrane softening spray zone, it is redirected to the supply branch of the membrane softening spray zone.

[0118] Before switching water paths, the controller pre-adjusts the output of the circulating water pump and the opening of the independent regulating valve based on the calibrated resistance of the target water path. After switching water paths, the controller re-collects the pressure and flow rate of each spray area. Successful path switching is confirmed when the pressure and flow rate enter the target range within the allowable time. If the pressure or flow rate does not recover, the controller returns to the pre-switching spray hot water cascade reuse path. A hydrocyclone grading and recovery device is installed downstream of the drainage and sewage discharge mechanism. The calcium eggshell particle identification results and particle size distribution are input into the flow ratio control of the hydrocyclone grading and recovery device. When the cumulative mass of calcium eggshell particles increases within the time window, the underflow recovery ratio is increased. The underflow enters the solid recovery zone of the cascade recovery tank, and the overflow enters the settling zone. The calcium eggshell particles in the solid recovery zone enter the subsequent dewatering treatment process. In this embodiment, the risk output of calcium eggshell particle loss is used as the control input of the hydrocyclone grading and recovery device, forming a continuous data chain between upstream online identification, loss risk, and downstream recovery path.

[0119] In one specific implementation case, the membrane-coated eggshell material enters the inclined screw conveyor at a feed rate of 240 kg / h. The axial lengths of the membrane softening spray zone, the peeling spray zone, and the final rinsing spray zone are 1.2 m, 1.4 m, and 0.8 m, respectively. The actual screw rotation speed and the actual axial conveying speed corresponding to the feed load are 0.015 m / s, 0.018 m / s, and 0.02 m / s, respectively. Therefore, the actual residence times in the three spray zones are 80 s, approximately 77.8 s, and 40 s, respectively.

[0120] The effective spray temperatures in the three spray zones were 62℃, 63℃, and 61.5℃, respectively, with a reference temperature of 55℃ for eggshell membrane softening. According to the formula for effective heat transfer from the eggshell membrane, the heat contributions from the three zones were 560 ℃·s, 622.4 ℃·s, and 260 ℃·s, respectively, with a cumulative effective heat transfer from the eggshell membrane of 1442.2 ℃·s. The effective heat transfer from the eggshell membrane is considered normal when the target heat transfer range is 1350 ℃·s to 1550 ℃·s.

[0121] The drainage image detection structure identified a calcium eggshell particle concentration of 0.32 g / L, compared to a reference value of 0.5 g / L. The high-resolution particle size was 1.8 mm, with a reference size of 2.5 mm. The current drainage flow rate was 1.7 m³ / h, compared to a reference value of 1.8 m³ / h. With weights of 0.45, 0.35, and 0.2 respectively, the risk value for calcium eggshell particle loss was approximately 0.729.

[0122] The spray pressure, spray flow rate, screw drive output torque, and actual screw speed are all within the corresponding target ranges. The eggshell membrane has reached the softening condition due to effective thermal action. The risk of calcium eggshell particle loss has not entered the warning range. The controller has formed a normal state of hydraulic-mechanical coordination and maintains the control values ​​of heating, spraying, and screw conveying.

[0123] The circulating water tank level is 68% of its effective volume, the circulating water turbidity is 110 NTU, and the circulating water conductivity is 1.8 mS / cm. The water level meets the operating conditions of the heater and circulating water pump. The turbidity has entered the filtration enhancement range, and the conductivity has not reached the partial drainage threshold. The controller increases the filter operation intensity and keeps the water supply valve and drain valve closed.

[0124] Historical material time windows corresponding to the output quality inspection show that the target eggshell membrane peeling rate was 93%, the actual eggshell membrane peeling rate was 89%, and the recovery rate of calcium eggshell particles met the target requirements. The previous target lower limit of thermal action was 1350℃·s with a calibration coefficient of 0.3; the updated target lower limit of thermal action is approximately 1367.4℃·s. The updated results were used for subsequent material time windows after being verified within the equipment's allowable range.

[0125] The controller executes the updated control parameters and re-acquires multi-source sensing data. The heater's operating status, the actual speed of the circulating water pump, the actual opening degree of the independent regulating valve, and the actual speed of the screw all match the control commands, and the temperature, pressure, and flow rate change in the expected direction. After the eggshell membrane's effective thermal effect, the hydraulic-mechanical coordination status, and the risk of calcium eggshell particle loss are within the target range for three consecutive washing control cycles, the controller ends the current correction cycle and maintains the control quantity.

[0126] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0127] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-source sensing-based eggshell washing control method, applied to the hot water spray washing and membrane-shell separation process of eggshell materials with membranes, characterized in that, Includes the following steps: Collect zoned hot water temperature data, spray hydraulic status data, screw drive load data, discharged solids status data, and circulating hot water status data; perform time correlation and validity verification on the multi-source sensing data to form effective multi-source sensing data. The effective thermal state of the eggshell membrane is determined based on the effective zone hot water temperature data and the actual residence time of the membrane-covered eggshell material in each spray zone. After the eggshell membrane reaches the softening condition under effective thermal action, the hydraulic-mechanical coordination state is determined based on the effective spray hydraulic state data and the effective screw drive load data. Identify calcium-rich eggshell particles from effective drainage solid state data, determine the risk of calcium-rich eggshell particle loss based on the state of the calcium-rich eggshell particles and the drainage flow rate, and determine the availability of circulating hot water based on effective circulating hot water state data. The adjustment range of spray control and spiral conveying control is limited by the risk of calcium eggshell particle loss, and the direction of hydraulic-mechanical coordinated adjustment is limited by the effective thermal effect state of the eggshell membrane. The control quantities of heating, spraying, spiral conveying, water replenishment and drainage are generated in combination with the availability of circulating hot water. After the control quantities are executed, execution feedback and new multi-source sensing data are collected, and the control quantities are corrected according to the direction of change of the target state until the target state is continuously in the target range or the abnormal termination condition is triggered.

2. The eggshell washing control method based on multi-source sensing according to claim 1, characterized in that: The zoned hot water temperature data includes the circulating water tank temperature, heater outlet temperature, spray temperature and return water temperature of each spray zone; the spray hydraulic status data includes the spray pressure and spray flow rate of the main water supply pipe and zoned water supply branches; the screw drive load data includes the screw drive current, screw drive output torque, screw set speed and screw actual speed; the drained solid status data includes the drained flow rate, drained solid image or online screening detection results; the circulating hot water status data includes the circulating water tank level, circulating water turbidity and circulating water conductivity; data from different sampling periods are processed according to the washing control cycle, using the most recent effective value retention, periodic averaging or periodic statistics, to form time-aligned multi-source sensing data.

3. The eggshell washing control method based on multi-source sensing according to claim 2, characterized in that: The validity verification of multi-source sensing data includes range verification, rate of change verification, continuous invariance verification, and physical response correlation consistency verification. The physical response correlation consistency verification is used to compare the heater power change with temperature response, the circulating water pump output change with spray pressure and spray flow response, the independent regulating valve opening change with the corresponding spray area flow response, and the screw set speed change with the actual screw speed and screw drive current response. When a single non-critical data is invalid, the most recent valid value is maintained, the state is frozen, or the control range is limited. When a combination of critical data is invalid, the feeding of the eggshell material with film is stopped and the machine enters a restricted operation state or a venting shutdown state.

4. The eggshell washing control method based on multi-source sensing according to claim 1, characterized in that: The actual axial conveying speed of the eggshell material with film is determined from the axial conveying speed calibration data table based on the actual screw speed and the current feed load. The actual residence time is determined based on the axial length of each spray zone and the actual axial conveying speed. The effective heat effect of the eggshell film is determined based on the effective spraying temperature and actual residence time of each spray zone. Spray zones with spraying temperatures lower than the eggshell film softening reference temperature do not contribute negative heat effects. The state of insufficient heat treatment, normal heat treatment, or excessive heat treatment is determined based on the position of the effective heat treatment amount of the eggshell membrane relative to the target heat treatment range.

5. The eggshell washing control method based on multi-source sensing according to claim 1, characterized in that: The spray hydraulic action state is determined based on the spray pressure and spray flow rate, and the screw mechanical action state is determined based on the screw drive output torque, screw set speed, screw actual speed, and the continuity of calcium eggshell particle discharge. After the eggshell membrane reaches the softening condition under effective thermal action, the combination of the spray hydraulic action state and the screw mechanical action state determines whether the hydraulic action is insufficient, the mechanical tumbling is insufficient, the hydraulic-mechanical coordination is normal, the risk of calcium eggshell particle breakage is high, the state of eggshell material accumulation with membrane is high, or the mechanical resistance state of the inclined screw conveyor is high. The allowable adjustment direction of the spray control quantity and the screw conveyor control quantity is determined according to the state category.

6. The eggshell washing control method based on multi-source sensing according to claim 1, characterized in that: Extract particle projected area, equivalent diameter, aspect ratio, edge thickness, and movement velocity from the solid images of the drained liquid, or obtain the retention mass of different particle size ranges through an online sieving structure. Differentiate eggshell membrane fragments from calcareous eggshell particles based on solid morphology characteristics or sieving results. Determine the risk of calcareous eggshell particle loss based on the concentration, particle size distribution, and drain flow rate of the identified calcareous eggshell particles, and convert the risk of calcareous eggshell particle loss into upper limits for spray control near the drain and sewage discharge mechanism, allowable ranges for spiral conveyor control, and solid recovery path switching instructions.

7. The eggshell washing control method based on multi-source sensing according to claim 1, characterized in that: The permissible control domain is formed according to the priority order of safety protection status, effective status of multi-source sensing data, accumulation status of membrane-coated eggshell material, mechanical obstruction status of inclined screw conveyor, risk of calcium eggshell particle loss, effective thermal effect status of eggshell membrane, hydraulic-mechanical coordination status, and availability of circulating hot water. When the risk of calcium eggshell particle loss exceeds the limit, it is prohibited to continue to increase the spray control quantity near the drainage and sewage discharge mechanism; when the effective thermal effect status of eggshell membrane is insufficient, it is prohibited to increase the processing capacity; when the screw drive load is close to the permissible upper limit, it is prohibited to continue to reduce the actual screw speed. When the number of consecutive washing control cycles in a critical state is within the target range, the control quantity is maintained until the maximum number of corrections is reached or the safety protection is triggered, at which point the control quantity correction ends.

8. The eggshell washing control method based on multi-source sensing according to claim 3, characterized in that: The control commands are compared with the heater's operating status, the actual speed of the circulating water pump, the actual opening degree of the independent regulating valve, the actual speed of the screw drive motor, the actual position of the water supply valve, and the actual position of the drain valve. The execution feedback is also compared with the direction of change of the corresponding physical quantity within the allowable response time. If the actuator has responded and the target state has improved, the verification continues until stability is achieved. If the actuator has responded but the target state has not improved, the control quantity is further corrected or the feed rate is reduced within the allowable control domain. If the actuator does not respond, the corresponding control quantity is frozen and the operation enters a restricted state. The accumulation state of the membrane-coated eggshell material and the mechanical stagnation state of the inclined screw conveyor are distinguished based on the screw drive current, screw drive output torque, speed deviation, and the continuous discharge status of the calcium eggshell particles. In the mechanical stagnation state, the controls are stopped, briefly reversed, stopped again, and resumed forward rotation.

9. The eggshell washing control method based on multi-source sensing according to claim 4, characterized in that: Collect the feed particle size distribution, and divide the membrane-covered eggshell material into different feed particle size grades according to the average particle size and high percentile particle size, and call the corresponding target thermal action range for different feed particle size grades. When the feed particle size increases, the target thermal effect range should be increased or the allowable residence time should be extended. When the feed particle size decreases, the target thermal effect range should be reduced or the allowable residence time should be shortened. Furthermore, when the risk of calcium eggshell particle loss exceeds the limit, it is prohibited to compensate for insufficient thermal effect by increasing the low-level spray flow rate.

10. A multi-source sensing-based eggshell washing control system, used to execute the multi-source sensing-based eggshell washing control method according to any one of claims 1-9, characterized in that: It includes an inclined screw conveyor mechanism, a hot water spray mechanism, a circulating hot water mechanism, a liquid and sewage discharge mechanism, a cascaded recycling tank, a multi-source sensing module, a controller, and an actuator; The inclined screw conveyor has a feed inlet, a top discharge outlet, and a drain outlet, with the drain outlet located at the lower end of the inclined screw conveyor. The hot water spraying mechanism is arranged above the inclined spiral conveying mechanism along its axial direction, and includes a membrane softening spraying area, a peeling spraying area, and an end rinsing spraying area. Each spraying area is equipped with a nozzle and an independent regulating valve. The circulating hot water mechanism includes a circulating water tank, a heater, a circulating water pump, and a filter. The circulating water pump delivers the hot water from the circulating water tank to each spray area of ​​the hot water spray mechanism after passing through the filter and the heater. The liquid discharge and sewage discharge mechanism is located downstream of the liquid discharge and sewage discharge port, and the cascade recovery tank is located downstream of the liquid discharge and sewage discharge mechanism, used to receive the discharged liquid and separate and recover the solids; The multi-source sensing module includes temperature sensors, pressure sensors, flow sensors, current detection units, torque detection units, speed detection units, drainage flow detection units, solid particle detection units, liquid level sensors, turbidity sensors, and conductivity sensors installed on various devices. The actuator includes a heater, a circulating water pump, independent regulating valves for each spray zone, a screw drive motor, a water supply valve, and a drain valve. The controller includes a processor and a memory. The memory stores a data validity verification program, a state determination program, an allowable control domain generation program, an execution control program, and a feedback correction program. The controller is communicatively connected to the multi-source sensing module and each actuator. When the processor executes the program, the data validity verification program receives the output from the multi-source sensing module and outputs valid multi-source sensing data to the state determination program. The state determination program outputs the effective thermal state of the eggshell membrane, the hydraulic-mechanical coordination state, the risk of calcium eggshell particle loss, and the availability of circulating hot water. The allowable control domain generation program receives each state and outputs control quantities for heating, spraying, spiral conveying, water replenishment, and drainage. The execution control program sends the control quantities to the corresponding actuators. The feedback correction program receives feedback from the actuators and new multi-source sensing data and updates the data validity state and control quantities until the critical state is continuously within the target range or an abnormal termination condition is triggered.

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