Micro liquid adding device and control method thereof

Abstract

The invention relates to the technical field of liquid adding, the liquid adding device comprises a shell, a weighing device and a spraying device, the weighing device comprises a weighing table and a weighing tank, the weighing table is arranged in the shell, the weighing tank is arranged on the weighing table, the spraying device comprises a nozzle, a spraying pipeline and a spraying pump, the nozzle is arranged on the shell, the spraying pipeline is communicated with the nozzle and the weighing tank, and the spraying pump is arranged on the weighing table. The injection pump is arranged on the injection pipeline, high-precision weight data are provided through the weighing device, on one hand, the actual total injection amount can be directly reflected without depending on instantaneous flow measurement on the pipeline, and therefore accumulative errors caused by pressure fluctuation, liquid viscosity changes or equipment aging can be reduced; the liquid adding amount monitoring device can be combined with a weighing device to monitor and control the liquid adding amount, so that the influence of the external environment on internal parts is reduced, a reliable basis is provided for subsequent accurate control, and the final product quality and the stability of the production process are guaranteed.

Description

Technical Field

[0001] This application relates to the technical field of micro-liquid addition, and in particular to a micro-liquid addition device and its control method. Background Technology

[0002] Micro-liquid addition systems are widely used in chemical, food, and biopharmaceutical industries. Their core lies in the precise control of liquid flow rate to ensure consistent coating quality and efficiency. In these systems, the accuracy of liquid addition directly affects the quality of the final product, the conversion rate of chemical reactions, and the stability of the production process. Therefore, how to accurately measure and control the amount of micro-liquid added is a core issue that continues to be a focus of research in this field.

[0003] Currently, in mainstream micro-liquid dosing systems, the most common flow measurement method is to install flow meters, such as turbine flow meters, Coriolis mass flow meters, or electromagnetic flow meters, in the injection line. By reading the instantaneous flow data measured by the flow meter in real time and integrating it over time, the total amount of liquid injected over a period of time can be estimated. The control system compares this estimated total amount with a preset target value and adjusts the pump valve through closed-loop or open-loop methods to achieve precise control of the total dosing amount. This control logic based on instantaneous flow measurement is currently a common technical solution for achieving automated liquid dosing.

[0004] However, relying solely on a single flow meter makes the measurement results susceptible to fluctuations in pipeline pressure, changes in liquid viscosity, or equipment aging, leading to increased cumulative errors and insufficient control accuracy. This is particularly problematic in micro-volume spraying scenarios, where even minute errors can severely impact the coating effect. Furthermore, the lack of an effective calibration mechanism prevents real-time verification of the flow meter's accuracy, resulting in unstable flow control and poor repeatability. More importantly, the flow meter itself suffers from manufacturing tolerances and accuracy drift due to wear and aging over long-term use, requiring periodic and complex offline calibrations. This not only increases maintenance costs but also fails to guarantee consistent measurement values. Summary of the Invention

[0005] To address the issues of low control accuracy and insufficient reliability of the total amount of liquid injected in existing micro-liquid addition systems, this application provides a micro-liquid addition device and its control method.

[0006] Firstly, the micro-liquid addition device provided in this application adopts the following technical solution: A micro-liquid addition device includes a housing, a weighing device, and a spraying device. The weighing device includes a weighing platform and a weighing tank. The weighing platform is disposed inside the housing, and the weighing tank is disposed on the weighing platform. The spraying device includes a nozzle, a spraying pipeline, and a spraying pump. The nozzle is disposed in the housing, the spraying pipeline connects the nozzle and the weighing tank, and the spraying pump is disposed in the spraying pipeline to control the nozzle to spray liquid.

[0007] By adopting the above technical solution, the weighing device provides high-precision weight data, which can directly reflect the actual total spray volume without relying on the instantaneous flow measurement on the pipeline. This reduces the cumulative errors caused by pressure fluctuations, changes in liquid viscosity, or equipment aging. Furthermore, by setting up the spraying device, it can be combined with the weighing device to monitor and control the amount of liquid added, thereby reducing the impact of the external environment on internal components. This ensures that even small changes in flow rate can be captured in time during micro-spraying, providing a reliable basis for subsequent precise control, and thus helping to ensure the quality of the final product and the stability of the production process.

[0008] Optionally, the injection device further includes a flow meter disposed in the injection pipeline, the flow meter being disposed on the outlet side of the injection pump; and / or, the injection pump includes a servo pump.

[0009] By adopting the above technical solutions, the flow rate of the pumped liquid can be monitored more accurately, enabling the control system to respond quickly and adjust the working state of the injection pump to maintain the set instantaneous flow rate, thereby ensuring the stability of the injection process. At the same time, the use of a servo pump can significantly improve the accuracy and stability of liquid delivery, ensuring a high degree of consistency in the amount of liquid injected each time, effectively reducing flow fluctuations during the injection process. This not only allows for precise control of the total amount of liquid injected but also optimizes the dynamic process of injection, making the liquid injection more uniform and stable, thus helping to improve product quality and production efficiency.

[0010] Optionally, the injection device further includes a pressure sensor disposed in the injection pipeline, the pressure sensor being located between the injection pump and the flow meter.

[0011] By adopting the above technical solution, the pressure of the injection pipeline can be monitored in real time, enabling the control device to predict the flow rate change trend in advance. This allows for proactive adjustment of the working status of the injection pump or subsequent pressure regulating components, offsetting errors caused by pressure fluctuations. This not only improves the stability of instantaneous flow rate but also reduces the cumulative error caused by sudden pressure changes, making the injection process of trace liquids smoother and effectively improving the consistency of the injection effect.

[0012] Optionally, the injection device further includes an overflow valve and a return pipeline. The overflow valve is located in the injection pipeline and between the pressure sensor and the injection pump. The return pipeline connects the overflow valve and the weighing tank.

[0013] By adopting the above technical solution, the system can self-regulate pipeline pressure, reducing flow fluctuations and uneven spraying caused by unstable pressure. This not only helps extend the service life of the jet pump and flow meter, but also provides a constant driving force for the nozzle, making the jetted liquid stream or atomized particles more uniform, thereby ensuring the accuracy of micro-liquid addition.

[0014] Optionally, the injection device further includes a three-way valve, a bypass line, and a pressure gauge. The three-way valve is located in the injection line, one end of the bypass line is connected to the three-way valve, and the other end is connected to external air. The pressure gauge is located in the bypass line.

[0015] By adopting the above technical solution, operators can perform pressure tests or calibrations on the flow meter without complicated disassembly steps, which can greatly reduce maintenance difficulty and time costs.

[0016] Optionally, the weighing device and the spraying device are configured as spray groups in a one-to-one correspondence, and two spray groups are provided, with the two spray groups spaced apart.

[0017] By adopting the above technical solution to achieve parallel processing, each group has its own weighing and spraying unit, allowing liquid to be added simultaneously or alternately, so that the micro-liquid addition device can add two different liquids at the same time, or when one spraying group fails, another spraying group can immediately take over the work, ensuring the continuity of production and thus helping to improve the reliability of the system.

[0018] Optionally, the micro-liquid addition device further includes a feeding device, which includes a feeding pipe and a feeding pump. The inlet of the feeding pipe is connected to the raw material tank, and the outlet is connected to the weighing tank. The feeding pump is located in the feeding pipe.

[0019] By adopting the above technical solution, liquid can be automatically replenished from the raw material tank according to the consumption of liquid in the weighing tank, thereby reducing the frequency of manual intervention and labor intensity. This can improve production efficiency and avoid pollution or errors that may be caused by manual feeding, thus ensuring a smooth and clean production process.

[0020] Secondly, the liquid spraying control method provided in this application adopts the following technical solution: A liquid spraying control method, based on the aforementioned micro-liquid adding device, the micro-liquid adding device comprising a housing, a weighing device, and a spraying device, the weighing device comprising a weighing platform and a weighing tank, the weighing platform being disposed within the housing, the weighing tank being disposed within the weighing platform, the spraying device comprising a nozzle, a spraying pipeline, and a spraying pump, the nozzle being disposed within the housing, the spraying pipeline connecting the nozzle and the weighing tank, and the spraying pump being disposed within the spraying pipeline for controlling the nozzle to spray liquid, the liquid spraying control method comprising: S10: Obtain the actual flow velocity of the liquid in the injection pipeline and determine the first injection flow rate of the nozzle; S20: Control the operation of the injection pump according to the first injection flow rate and the preset injection flow rate; S30: Determine the second injection flow rate of the nozzle based on the actual weight, and determine the injection flow rate difference of the nozzle based on the first injection flow rate and the second injection flow rate; S40: Determine the actual jet flow rate of the nozzle based on the jet flow rate difference and the preset flow rate threshold.

[0021] By adopting the above technical solution, the weighing data can directly reflect the actual total amount of liquid sprayed, effectively correcting the error of the flow meter. The instantaneous flow data of the flow meter can ensure the real-time control. Through the verification and screening of dual flow data, the measurement accuracy of the spray flow rate is greatly improved, making the spray flow rate of trace liquids more precise, thereby significantly improving the consistency of spray quality and the stability of the production process.

[0022] Optionally, the step of determining the actual jet flow rate of the nozzle based on the jet flow rate difference and a preset flow rate threshold includes: S41: When the difference in injection flow rate is greater than a preset flow rate threshold, the second injection flow rate is taken as the actual injection flow rate; S42: When the difference in injection flow rate is less than a preset flow rate threshold, the first injection flow rate is taken as the actual injection flow rate.

[0023] By adopting the above technical solution, the system can automatically identify possible errors or abnormalities in the flow meter and switch to the more reliable actual flow rate provided by the weighing data in a timely manner. This allows the system to fully utilize the real-time advantage of the flow meter while ensuring high precision, thereby ensuring that the system can maintain stable high-precision injection under different operating conditions.

[0024] Optionally, after the steps of determining the second injection flow rate of the nozzle based on the actual weight and determining the difference in injection flow rate of the nozzle based on the first injection flow rate and the second injection flow rate, the method further includes: S50: At each interval, a preset frequency parameter is used to determine the first jet flow rate, and anomaly counting is performed based on the determination result; S60: Repeat step 50 to determine the cumulative abnormal count of the jet flow rate. When the cumulative abnormal count is greater than the preset count threshold, decrease the preset frequency parameter.

[0025] By adopting the above technical solution, through cumulative anomaly counting and dynamic adjustment of the judgment interval, it is beneficial to quickly detect changes in the performance of the flow meter and avoid the expansion of cumulative errors caused by the decrease in flow accuracy. On the other hand, it avoids over-adjustment caused by a single accidental fluctuation, which helps to improve the stability of the system. It can maintain high control accuracy for a long time, reduce the impact of factors such as equipment aging and environmental changes, and improve the operational reliability and service life of the system. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the liquid adding device provided in this application; Figure 2 yes Figure 1 A three-dimensional structural diagram of the liquid addition device (hidden feeding device); Figure 3 yes Figure 1 A three-dimensional structural diagram of the central injection device at one angle; Figure 4 yes Figure 1 A three-dimensional structural diagram of the central injection device from another angle; Figure 5 yes Figure 1 A side view of the central injection device; Figure 6 This is a schematic diagram of the structure of the control device for the hardware operating environment involved in the embodiments of this application; Figure 7 This is a schematic flowchart of the liquid spraying control method provided in this application.

[0027] Explanation of reference numerals in the attached figures: 100. Micro-liquid addition device; 1. Shell; 11. Shell body; 12. Fixing plate; 2. Weighing device; 21. Weighing platform; 22. Weighing tank; 3. Spraying device; 31. Nozzle; 32. Spraying pipeline; 33. Spray pump; 34. Flow meter; 35. Pressure sensor; 361. Overflow valve; 362. Return pipeline; 371. Three-way valve; 372. Bypass pipeline; 373. Pressure gauge; 38. Pressure regulating valve; 4. Feeding device; 41. Feeding pipe; 42. Feeding pump; 5. Raw material tank. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1 -Appendix Figure 5 This application will be described in further detail below.

[0029] In one embodiment of this application, please refer to Figures 1 to 3 The micro-liquid addition device 100 includes a housing 1, a weighing device 2, and a spraying device. The weighing device 2 includes a weighing platform 21 and a weighing tank 22. The weighing platform 21 is disposed inside the housing 1, and the weighing tank 22 is disposed on the weighing platform 21. The spraying device includes a nozzle 31, a spraying pipe 32, and a spraying pump 33. The nozzle 31 is disposed in the housing 1, the spraying pipe 32 connects the nozzle 31 and the weighing tank 22, and the spraying pump 33 is disposed in the spraying pipe 32 to control the nozzle 31 to spray liquid.

[0030] Understandably, the housing 1 provides mounting support for the internal components, the weighing platform 21 of the weighing device 2 is fixed inside the housing 1, the weighing tank 22 is placed on the weighing platform 21 to monitor the change in the weight of the liquid in the tank in real time, the nozzle 31 of the spraying device is used for liquid spraying, the spraying pipe 32 connects the weighing tank 22 and the nozzle 31 to form a liquid flow channel, and the spraying pump 33 is set on the spraying pipe 32 to drive the liquid flow and control the spraying process.

[0031] In the technical solution of this application, the weighing device 2 provides high-precision weight data, which can directly reflect the actual total amount of spraying without relying on the instantaneous flow measurement on the pipeline. This reduces the cumulative error caused by pressure fluctuations, changes in liquid viscosity, or equipment aging. By setting up a spraying device to be combined with the weighing device 2, the amount of liquid added can be monitored and controlled, so as to reduce the influence of the external environment on internal components. This ensures that even small changes in flow rate can be captured in time during micro-spraying, providing a reliable basis for subsequent precise control, thereby helping to ensure the quality of the final product and the stability of the production process.

[0032] In order for nozzle 31 to stably spray liquid, in this embodiment, please refer to... Figures 3 to 5 The injection device also includes a flow meter 34 located in the injection pipeline 32, which is located at the outlet side of the injection pump 33.

[0033] Since the flow at the pump outlet is relatively stable and less affected by pump fluctuations, the flow meter 34 is positioned downstream of the pump to more accurately monitor the pumped liquid flow rate. This allows the control system to quickly respond and adjust the operating state of the jet pump 33 to maintain the set instantaneous flow rate, thus ensuring the smoothness of the jetting process. Simultaneously, the flow meter 34 data and weighing data can be cross-referenced and calibrated. This reduces the potential accumulation of errors from a single flow meter 34 and provides a reliable reference for the online calibration of the flow meter 34 itself, effectively improving the overall measurement accuracy and reliability. This significantly enhances the system's operational stability and long-term accuracy maintenance capabilities.

[0034] In one embodiment of this application, the jet pump 33 includes a servo pump. Since servo pumps are typically driven by servo motors, they can achieve precise speed and displacement control, thereby directly controlling the volume or mass of the pumped liquid. The principle is that the servo motor can adjust the speed and angle of the output shaft in real time according to the received command signal, thereby precisely controlling the piston displacement or rotor speed of the pump. This ensures that a preset amount of liquid is delivered in each cycle, and the response speed is fast, quickly reaching or changing the target flow rate. Therefore, using a servo pump can significantly improve the accuracy and stability of liquid delivery, ensuring a highly consistent liquid volume in each jet, effectively reducing flow fluctuations during the jetting process. It can precisely control the total amount of liquid jetted and optimize the dynamic process of jetting, making the liquid jetting more uniform and stable, thereby helping to improve product quality and production efficiency.

[0035] In one embodiment of this application, please refer to Figure 5 The spraying device also includes a pressure sensor 35 located in the spraying pipeline 32. The pressure sensor 35 is located between the spraying pump 33 and the flow meter 34. This allows for real-time monitoring of the pressure in the spraying pipeline 32, enabling the control device to predict flow rate changes in advance and proactively adjust the working state of the spraying pump 33 or subsequent pressure regulating components to offset errors caused by pressure fluctuations. This not only improves the stability of instantaneous flow rate but also reduces the cumulative error caused by sudden pressure changes, making the spraying process of micro-liquids smoother and effectively improving the consistency of the spraying effect.

[0036] In one embodiment of this application, please refer to Figures 3 to 5 The spraying device also includes an overflow valve 361 and a return pipe 362. The overflow valve 361 is located in the spraying pipe 32 and between the pressure sensor 35 and the spraying pump 33. The return pipe 362 connects the overflow valve 361 and the weighing tank 22. When the pressure in the spraying pipe 32 exceeds the preset value, the overflow valve 361 will automatically open, allowing some liquid to flow back to the weighing tank 22 through the return pipe 362, thereby stabilizing the pipe pressure. In this way, by setting the overflow valve 361 and the return pipe 362, the system can self-regulate the pipe pressure, reducing flow fluctuations and uneven spraying caused by unstable pressure. This not only helps to extend the service life of the spraying pump 33 and the flow meter 34, but also provides a constant driving force for the nozzle 31, making the sprayed liquid stream or atomized particles more uniform, thereby ensuring the accuracy of micro-liquid addition.

[0037] For ease of calibration of flow meter 34, please refer to one embodiment of this application. Figure 5The injection device also includes a three-way valve 371, a bypass line 372, and a pressure gauge 373. The three-way valve 371 is located in the injection line 32. One end of the bypass line 372 is connected to the three-way valve 371, and the other end is connected to external air. The pressure gauge 373 is located in the bypass line 372. When the flow meter 34 needs to be calibrated, the three-way valve 371 is switched so that the liquid can flow out through the bypass line 372. The pressure gauge 373 is used to monitor the line pressure for calibrating or purging the flow meter 34. In this way, through the three-way valve 371 and the bypass line 372, operators can perform pressure tests or calibrations on the flow meter 34 without complicated disassembly steps, which can greatly reduce maintenance difficulty and time costs.

[0038] In one embodiment of this application, please refer to Figures 3 to 5 The weighing device 2 and the spraying device are configured as spraying groups in a one-to-one correspondence. There are two spraying groups, which are set at intervals. In this way, by setting two independent spraying groups, parallel processing can be achieved. Each group has its own weighing and spraying unit, which allows liquid to be added simultaneously or alternately. This enables the micro-liquid adding device 100 to add two different liquids at the same time, or if one spraying group fails, the other spraying group can immediately take over the work, ensuring the continuity of production and thus helping to improve the reliability of the system.

[0039] It is understood that the liquids in the weighing tanks 22 of the two spray groups may be the same or different, and the embodiments of this application do not limit this.

[0040] In one embodiment of this application, please refer to Figures 3 to 5 The spraying device also includes a pressure regulating valve 38 located in the spraying pipeline 32. The pressure regulating valve 38 is located between the flow meter and the nozzle 31. Thus, by setting the pressure regulating valve 38 between the flow meter 34 and the nozzle 31, the pressure in front of the nozzle 31 can be controlled independently, so that it is not affected by upstream pressure fluctuations, which helps to improve the accuracy, repeatability and consistency of spraying effect.

[0041] In one embodiment of this application, please refer to Figure 1 and Figure 3 The micro-liquid addition device 100 also includes a feeding device 4, which includes a feeding pipe 41 and a feeding pump 42. The inlet of the feeding pipe 41 is connected to the raw material tank 5, and the outlet is connected to the weighing tank 22. The feeding pump 42 is located in the feeding pipe 41. In this way, by setting up the feeding device 4, the liquid can be automatically replenished from the raw material tank 5 according to the consumption of liquid in the weighing tank 22, thereby reducing the frequency of manual intervention and labor intensity, improving production efficiency, and avoiding pollution or errors that may be caused by manual feeding, thus ensuring the smoothness and cleanliness of the production process.

[0042] In one embodiment of this application, please refer to Figures 1 to 3 The housing 1 includes a housing body 11 and a fixing plate 12. The fixing plate 12 is disposed inside the housing 1 and extends vertically for mounting the injection pipe 32. Thus, by setting the fixing plate 12, the injection pipe 32 and its related components are supported and fixed, preventing the pipe from vibrating or shifting during operation, thereby ensuring the stability and sealing of the pipe connection. At the same time, the fixing part extends vertically so that the pipe system can be arranged vertically, which helps to optimize the internal space layout of the housing body 11, thereby helping to improve the space utilization of the housing body 11.

[0043] In one embodiment of this application, in order to control the liquid ejection from the nozzle 31, the micro-liquid addition device 100 further includes a control device, such as... Figure 6 As shown, the control device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen or an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wireless-Fidelity (Wi-Fi) interface). The memory 1005 may be high-speed random access memory (RAM) or stable non-volatile memory (NVM), such as a disk storage device. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0044] like Figure 6 As shown, the memory 1005, which serves as a storage medium, may include an operating system, a network communication module, a user interface module, and a control program for a control device.

[0045] exist Figure 6 In the control device shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the control device of this application can be set in the control device. The control device calls the control program of the control device stored in the memory 1005 through the processor 1001 and executes the control method of the control device provided in the embodiment of this application.

[0046] Those skilled in the art will understand that Figure 6 The structure shown does not constitute a limitation on the control device and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0047] Based on the above hardware structure, this application also provides a liquid spraying control method. Please refer to [link to relevant documentation]. Figure 7 , Figure 7 This is a schematic flowchart of the liquid spraying control method provided in this application.

[0048] The liquid spraying control method includes: S10: Obtain the actual flow velocity of the liquid in the injection pipeline and determine the first injection flow rate of nozzle 31; S20: Control the operation of the injection pump 33 according to the first injection flow rate and the preset injection flow rate; It should be noted that when the first jet flow rate is greater than the preset jet flow rate, it indicates that the jet flow rate of the nozzle 31 is too large. At this time, the rotation speed of the jet pump 33 is controlled to decrease in order to reduce the first jet flow rate until the first jet flow rate is equal to the preset jet flow rate. When the first jet flow rate is less than the preset jet flow rate, it indicates that the jet flow rate of the nozzle 31 is too small. At this time, the rotation speed of the jet pump 33 is controlled to increase in order to increase the first jet flow rate until the first jet flow rate is equal to the preset jet flow rate. In this way, the nozzle 31 can stably jet liquid at the preset jet flow rate.

[0049] S30: Determine the second injection flow rate of nozzle 31 based on the actual weight, and determine the injection flow rate difference of nozzle 31 based on the first injection flow rate and the second injection flow rate; S40: Determine the actual jet flow rate of nozzle 31 based on the jet flow rate difference and the preset flow rate threshold.

[0050] In this embodiment, the actual flow velocity of the liquid in the pipeline is obtained by the flow meter 34 to determine the first injection flow rate. The control device compares this flow rate with the preset injection flow rate and adjusts the operation of the injection pump 33 to reduce the deviation, so that the nozzle 31 can stably spray liquid at the preset injection flow rate. At the same time, the weighing device 2 monitors the actual weight change of the liquid in the weighing tank 22 and calculates the second injection flow rate. Then, the difference between the first injection flow rate and the second injection flow rate is combined with the preset flow rate threshold to determine the actual injection flow rate. When the difference is large, the second injection flow rate obtained from the weighing data is used; when the difference is small, the first injection flow rate of the flow meter 34 is used. This achieves the complementary advantages of the two measurement data. In this way, the weighing data can directly reflect the actual total amount of liquid injected and can effectively correct the error of the flow meter 34, while the instantaneous flow rate data of the flow meter 34 can ensure the real-time control. Through the verification and screening of dual flow data, the measurement accuracy of the injection flow rate is greatly improved, making the injection flow rate of trace liquids more precise, thereby significantly improving the consistency of injection quality and the stability of the production process.

[0051] In one embodiment of this application, step S40 includes: S41: When the difference in injection flow rate is greater than a preset flow rate threshold, the second injection flow rate is taken as the actual injection flow rate; S42: When the difference in injection flow rate is less than a preset flow rate threshold, the first injection flow rate is taken as the actual injection flow rate.

[0052] In this embodiment, when there is a significant difference (greater than the preset flow threshold) between the first jet flow rate measured by the flow meter 34 and the second jet flow rate calculated by the weighing device 2, it indicates that the flow meter 34 may have a large error or drift. In this case, the system prioritizes the more accurate and fundamental weighing data (second jet flow rate). Conversely, when the difference is small (less than the preset flow threshold), the data from the flow meter 34 is considered relatively reliable, and the more real-time first jet flow rate data it provides can continue to be used for control. Thus, by setting a flow difference threshold, the system can automatically identify possible errors or abnormalities in the flow meter 34 and promptly switch to the more reliable actual flow rate provided by the weighing data. This allows the system to maintain high precision while fully utilizing the real-time advantage of the flow meter 34, thereby ensuring that the system can maintain stable high-precision jetting under different operating conditions.

[0053] It should also be noted that when the difference in the injection flow rate is greater than the preset flow rate threshold, it indicates that the difference between the first injection flow rate and the second injection flow rate is too large. In this case, the rotation speed of the injection pump 33 needs to be adjusted to compensate for the first injection flow rate, thereby helping to accurately control the injection amount of the nozzle 31 and reduce injection error.

[0054] In one embodiment of this application, after step S40, the method further includes: S50: At each interval, a preset frequency parameter is used to determine the first jet flow rate, and anomaly counting is performed based on the determination result; It should be noted that the preset frequency parameter can be of various types, such as a time parameter, for example, 5s or 10s, or a weight parameter, for example, 5ml or 10ml. The specific parameters can be adjusted as needed, and the embodiments of this application do not limit them.

[0055] S60: Repeat step 50 to determine the cumulative abnormal count of the injection flow rate. When the cumulative abnormal count is greater than a preset count threshold, decrease the preset frequency parameter. Further, when the injection flow rate difference is greater than a preset flow rate threshold, increment the cumulative abnormal count by one; when the injection flow rate difference is less than or equal to the preset flow rate threshold, decrement the cumulative abnormal count by one. Thus, by adding and subtracting the cumulative abnormal count, abnormal situations can be statistically analyzed, interference from accidental factors can be eliminated, frequent adjustments to the injection volume of nozzle 31 can be avoided, and system oscillations can be reduced.

[0056] It is understood that the preset counting threshold can be of various types, such as 2, 3, 4 or 5, and can be adjusted as needed. The embodiments of this application do not limit this.

[0057] In this embodiment, when the cumulative number of abnormalities of the flow meter 34 exceeds a certain threshold, it indicates that the flow meter 34 may have long-term drift or performance degradation. At this time, the system will shorten the calibration cycle (reduce the preset frequency parameter) to make judgments and corrections more frequently, ensuring that potential problems of the flow meter 34 are detected and corrected in a timely manner. In this way, by accumulating abnormality counts and dynamically adjusting the judgment interval, it is beneficial to quickly detect performance changes of the flow meter 34 and avoid the expansion of cumulative errors caused by the decrease in the accuracy of the flow meter 34. On the other hand, it avoids over-adjustment caused by a single accidental fluctuation, which helps to improve the stability of the system. It can maintain high control accuracy for a long time, reduce the impact of factors such as equipment aging and environmental changes, and improve the operational reliability and service life of the system.

[0058] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A micro-liquid addition device, characterized in that, The micro-liquid addition device includes: Shell (1); The weighing device (2) includes a weighing platform (21) and a weighing tank (22), wherein the weighing platform (21) is disposed inside the housing (1) and the weighing tank (22) is disposed on the weighing platform (21); The spraying device includes a nozzle (31), a spraying pipeline (32), and a spraying pump (33). The nozzle (31) is located in the housing (1). The spraying pipeline (32) connects the nozzle (31) to the weighing tank (22). The spraying pump (33) is located in the spraying pipeline (32) and is used to control the nozzle (31) to spray liquid.

2. The micro-liquid addition device according to claim 1, characterized in that, The injection device further includes a flow meter (34) disposed in the injection pipeline (32), the flow meter (34) being located on the outlet side of the injection pump (33); and / or, The jet pump (33) includes a servo pump.

3. The micro-liquid addition device according to claim 2, characterized in that, The injection device also includes a pressure sensor (35) disposed in the injection pipeline (32), the pressure sensor (35) being located between the injection pump (33) and the flow meter (34).

4. The micro-liquid addition device according to claim 3, characterized in that, The injection device also includes an overflow valve (361) and a return pipe (362). The overflow valve (361) is located in the injection pipe (32) and between the pressure sensor (35) and the injection pump (33). The return pipe (362) connects the overflow valve (361) and the weighing tank (22).

5. The micro-liquid addition device according to claim 2, characterized in that, The injection device also includes a three-way valve (371), a bypass line (372), and a pressure gauge (373). The three-way valve (371) is located in the injection line (32) and between the flow meter (34) and the nozzle (31). One end of the bypass line (372) is connected to the three-way valve (371), and the other end is connected to the outside air. The pressure gauge (373) is located in the bypass line (372).

6. The micro-liquid addition device according to claim 1, characterized in that, The weighing device (2) and the spraying device are configured as spraying groups in a one-to-one correspondence. Two spraying groups are configured with an interval between them.

7. The micro-liquid addition device according to claim 1, characterized in that, The micro-liquid addition device also includes a feeding device (4), which includes a feeding pipe (41) and a feeding pump (42). The inlet of the feeding pipe (41) is connected to the raw material tank (5), and the outlet is connected to the weighing tank (22). The feeding pump (42) is located in the feeding pipe (41).

8. A liquid spraying control method, based on the micro-liquid addition device according to any one of claims 1 to 7, characterized in that, The liquid spraying control method includes: S10: Obtain the actual flow rate of the liquid in the spray pipeline and determine the first spray flow rate of the nozzle (31); S20: Control the operation of the injection pump (33) according to the first injection flow rate and the preset injection flow rate; S30: Obtain the actual weight of the liquid in the weighing tank (22), determine the second injection flow rate of the nozzle (31), and determine the difference in injection flow rate of the nozzle (31) based on the first injection flow rate and the second injection flow rate; S40: Determine the actual jet flow rate of the nozzle (31) based on the jet flow rate difference and the preset flow rate threshold.

9. The micro-liquid addition device according to claim 1, characterized in that, The step of determining the actual jet flow rate of the nozzle (31) based on the jet flow rate difference and the preset flow rate threshold includes: S41: When the difference in injection flow rate is greater than a preset flow rate threshold, the second injection flow rate is taken as the actual injection flow rate; S42: When the difference in injection flow rate is less than a preset flow rate threshold, the first injection flow rate is taken as the actual injection flow rate.

10. The micro-liquid addition device according to claim 1, characterized in that, After the steps of determining the second injection flow rate of the nozzle (31) based on the actual weight, and determining the difference in injection flow rate of the nozzle (31) based on the first injection flow rate and the second injection flow rate, the method further includes: S50: At each interval, a preset frequency parameter is used to determine the first jet flow rate, and anomaly counting is performed based on the determination result; S60: Repeat step 50 to determine the cumulative abnormal count of the jet flow rate. When the cumulative abnormal count is greater than the preset count threshold, decrease the preset frequency parameter.

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