Variable-frequency chemical dosing equipment and control method for fluorine-containing waste acid recycling agent

Abstract

The present invention discloses a variable-frequency chemical dosing device and a control method for recycled medicament of fluorine-containing waste acid, belonging to the technical field of water treatment. The device includes a spiral metering feeder, a reaction kettle, a sewage monitoring device, an image monitoring device, a PLC controller and a data analysis and management platform. The spiral metering feeder includes a variable-frequency motor, a spiral conveying shaft, a feed bin and a discharge port. The discharge port is connected to the reaction kettle. The image monitoring device is installed at the discharge port, and the sewage monitoring device is installed inside the reaction kettle. The data analysis and management platform is connected to the chemical dosing device and the PLC controller through the Internet of Things. The PLC controller controls the operation of the spiral metering feeder according to the control instructions. The present invention analyzes the information such as the images obtained by the image monitoring device, can automatically judge the feeding situation of the spiral metering feeder, can verify whether the medicament flows uniformly during the conveying process, and once an abnormality occurs, an alarm is given in time, which can prevent blockage or caking from affecting the chemical dosing accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of water treatment, and particularly relates to a variable-frequency dosing device and a control method for a reagent for recycling fluorine-containing waste acid. Background Art

[0002] As the core hazardous waste in high-end manufacturing industries such as photovoltaic and semiconductor, the fluorine ion concentration in fluorine-containing waste acid is as high as 5%-12%. Therefore, it is necessary to treat the fluorine-containing waste acid to meet the standards before discharging. Although the traditional lime neutralization method can achieve discharge up to the standard (F⁻ < 10 ppm), it produces low-purity calcium fluoride sludge (CaF₂ content < 65%), resulting in a low resource utilization benefit per ton of fluorine-containing waste acid. Directly preparing high-value-added fluorides (such as cryolite and fluorosilicate) or removing impurities and recycling hydrofluoric acid can effectively improve the resource utilization benefit of fluorine-containing waste acid. However, this recycling method requires the addition of solid reagents during treatment to ensure the treatment efficiency.

[0003] Traditional dosing mostly relies on manual operation. Workers adjust the rotation speed of the screw feeder according to experience. Manual operation is not only inefficient but also has a large lag in large-scale scenarios of recycling treatment of fluorine-containing waste acid, making it difficult to meet the real-time and continuous dosing requirements. At the same time, manual operation is easily affected by subjective factors of operators (such as experience, fatigue level, and sense of responsibility), resulting in an unstable dosing process, prone to product deviation, and ultimately affecting the treatment effect. In addition, due to the volatility of the composition and concentration of fluorine-containing waste acid, it is required that the dosing process can be accurately adjusted according to the real-time situation of the waste acid. However, the traditional dosing method lacks an effective real-time monitoring and feedback mechanism, cannot timely sense the change of the waste acid properties, and is difficult to timely adjust the dosing amount, resulting in inaccurate dosing and thus wasting reagents. Summary of the Invention

[0004] The purpose of the present invention is to provide a variable-frequency dosing device and a control method for a reagent for recycling fluorine-containing waste acid to solve the problems faced in the above background art.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A variable-frequency dosing device for a reagent for recycling fluorine-containing waste acid, the device includes a screw metering feeder, a reaction kettle, a sewage monitoring device, an image monitoring device, a PLC controller, and a data analysis and management platform;

[0007] The screw metering feeder includes a variable-frequency motor, a screw conveyor shaft, a feed bin, and a discharge port. The discharge port is connected to the reaction kettle. The image monitoring device is installed at the discharge port, and the sewage monitoring device is installed inside the reaction kettle. A stirring device is also installed inside the reaction kettle. The data analysis and management platform is connected to the chemical dosing equipment and the PLC controller through the Internet of Things. The PLC controller is used to control the operation of the screw metering feeder according to the control instructions.

[0008] A control method for a variable-frequency chemical dosing equipment for recycling medicaments for fluorine-containing waste acid. The control method is implemented by the variable-frequency chemical dosing equipment for recycling medicaments for fluorine-containing waste acid, and the control method includes:

[0009] Step 1: Pump the fluorine-containing waste acid into the reaction kettle, stop when the set liquid level is reached, and obtain various parameter information of the waste acid through the sewage monitoring device.

[0010] Step 2: Upload the obtained various parameter information to the data analysis and management platform for processing and analysis to determine the required dosage of solid medicament.

[0011] Step 3: According to the required dosage of solid medicament, the PLC controller controls the feeding time of the screw metering feeder to perform the feeding operation.

[0012] Step 4: During the chemical dosing process, the PLC controller controls the operation of the stirring device in the reaction kettle. After the required dosage of solid medicament is added, continue to detect the fluorine ion parameter in the waste acid. If it does not meet the standard, continue to add the dosage of medicament. Otherwise, discharge the wastewater to the next process.

[0013] Step 5: The data analysis and management platform analyzes the data information obtained by the image monitoring device to judge whether the feeding of the screw metering feeder is normal.

[0014] Further, the method for determining the required dosage of solid medicament in Step 2 is:

[0015] Obtain the fluorine ion concentration in the waste acid , pH value , calcium ion concentration , interfering ion concentration and the waste acid temperature value , and calculate the required dosage of solid medicament through the formula ; ;

[0016] where is the basic addition amount, is the optimal pH value, is the theoretical calcium ion requirement value, is the optimal temperature value, , is the total number of detected interfering ions, is the concentration of the i-th interfering ion, is the weight coefficient of the i-th interfering ion, and , is the reference value of the interfering ion concentration, is the pH deviation penalty coefficient, is the interfering ion influence coefficient, is the calcium ion saving coefficient, is the temperature compensation coefficient.

[0017] Furthermore, the method for determining the feeding time of the screw metering feeder in step three is as follows:

[0018] The feeding time is obtained through the formula ;

[0019] where is the calibration coefficient, is the pipe diameter of the feeder, is the current operating frequency of the variable frequency motor, is the bulk density of the chemical agent to be dispensed.

[0020] Furthermore, the workflow of step four is as follows:

[0021] Detect the fluoride ion concentration in the waste acid , and determine whether it reaches the target threshold concentration :

[0022] When the detected fluoride ion concentration in the waste acid reaches the target threshold concentration , it indicates that the treatment is up to standard, and the wastewater is discharged to the next process. If the detected fluoride ion concentration in the waste acid does not reach the target threshold concentration , then the secondary dosing amount is determined through the formula , and continuous dosing is carried out;

[0023] where is the chemical agent reaction efficiency coefficient, is the waste acid viscosity attenuation factor, is the stirring duration, is the error compensation amount.

[0024] Furthermore, the method for determining whether the feeding of the screw metering feeder is normal in step five is as follows:

[0025] Obtain an image information of the material every time, and perform grayscale conversion, noise reduction, and binarization processing on the image to extract the material transmission area in the image;

[0026] Divide the material transmission area into n sub - areas and obtain the gray - scale values of each sub - area , and at the same time, through the formula obtain the overall average gray - scale value ;

[0027] Through the formula obtain the coherence index of the feeding ;

[0028] When , it is determined that the feeding of the screw constant - quantity feeder is abnormal;

[0029] At the same time, when the screw constant - quantity feeder is operating normally, continuously obtain the coherence indices of N pieces of image information, so as to formulate a curve function of the coherence index changing with the number of image sheets x ;

[0030] Through the formula obtain the abnormal feeding value ;

[0031] When , it is determined that the feeding of the screw constant - quantity feeder is abnormal;

[0032] Among them, is the set coherence - index judgment threshold value, is the set abnormal - feeding judgment threshold value, is the maximum slope of is the minimum slope of is the slope reference value, is the last image obtained.

[0033] Furthermore, the data analysis and management platform is also used to monitor the operation status of the chemical - adding equipment, and the monitoring method is as follows:

[0034] During the period, obtain the number of times of abnormal feeding in each waste - acid treatment batch of the chemical - adding equipment ;

[0035] Through the formula obtain the status value ;

[0036] When , it is determined that the operation status of the chemical - adding equipment is abnormal;

[0037] Among them, is the set status - judgment threshold value, is the total number of waste - acid treatment batches carried out during the is is the number of batches in all processing batches where the number of abnormal feeding occurrences is greater than the average value.

[0038] Advantages of the present invention:

[0039] The present invention can perform comprehensive analysis based on parameters such as the fluoride ion concentration, pH value, temperature, and interfering ion concentration in the fluorine-containing waste acid to accurately obtain the required dosage of solid medicine. It can achieve precise dosing without manual operation, thereby reducing the waste of medicine dosage. At the same time, by detecting the fluoride ion concentration in the waste acid after adding the medicine, it can be used to detect in real time whether the waste acid treatment meets the standard. When it does not meet the standard, it combines parameters such as the medicine reaction efficiency coefficient and stirring duration for analysis to continue adding medicine dosage to the waste acid, ensuring the treatment effect while reducing the medicine dosage.

[0040] The present invention analyzes information such as images obtained by the image monitoring device, can automatically judge the feeding situation of the screw metering feeder, and can verify whether the flow of the medicine is uniform during transportation. Once an abnormality occurs, it will alarm in time to prevent blockage or caking from affecting the dosing accuracy.

[0041] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. Brief Description of the Drawings

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0043] Figure 1 is the structural diagram of the medicine adding device of the present invention;

[0044] Figure 2 is the control flow chart of the medicine adding device in the present invention.

[0045] Explanation of the accompanying drawings in the figure:

[0046] 1. Screw metering feeder; 2. Reaction kettle; 3. Sewage monitoring device; 4. Image monitoring device; 11. Variable frequency motor; 12. Screw conveyor shaft; 13. Silo; 14. Discharge port; 21. Stirring device. Detailed Embodiments

[0047] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0048] In one embodiment, a variable-frequency dosing device for a fluorine-containing waste acid recycling agent is disclosed. As Figure 1 shown, the device includes a screw metering feeder 1, a reaction kettle 2, a sewage monitoring device 3, an image monitoring device 4, a PLC controller, and a data analysis and management platform; the screw metering feeder 1 includes a variable-frequency motor 11, a screw conveyor shaft 12, a feed bin 13, and a discharge port 14. The discharge port 14 is connected to the reaction kettle 2. The image monitoring device 4 is installed at the discharge port 14. The image monitoring device 4 can be a high-definition camera probe. The sewage monitoring device 3 is installed inside the reaction kettle 2. The sewage monitoring device can be various monitoring devices, including but not limited to a fluoride ion concentration monitoring sensor, a temperature sensor, a pH monitor, etc. A stirring device 21 is also installed inside the reaction kettle 2; the data analysis and management platform is connected to the dosing device and the PLC controller through the Internet of Things. The data analysis and management platform obtains various parameter information in the waste acid, analyzes it to obtain the required dosage of the solid medicine, and then transmits it to the PLC controller. The PLC controller controls the feeding time of the screw metering feeder according to the required dosage of the solid medicine to perform the feeding operation. At the same time, the data analysis and management platform analyzes the image information obtained by the image monitoring device 4 to judge whether the screw metering feeder is abnormal and the operating condition of the entire dosing device, so as to ensure the efficiency of the entire treatment process.

[0049] In one embodiment, a control method for a variable-frequency dosing device for a fluorine-containing waste acid recycling agent is also disclosed. As Figure 2 shown, the control method includes:

[0050] Step 1: Pump the fluorine-containing waste acid into the reaction kettle, stop when the set liquid level is reached, and obtain various parameter information of the waste acid through the sewage monitoring device;

[0051] Step 2: Upload the obtained various parameter information to the data analysis and management platform for processing and analysis to determine the required dosage of the solid medicine;

[0052] Step 3: According to the required dosage of the solid medicine, the PLC controller controls the feeding time of the screw metering feeder to perform the feeding operation;

[0053] Step 4: During the chemical dosing process, the PLC controller controls the operation of the stirring device in the reactor. After the required amount of solid chemical has been added, continue to detect the fluoride ion parameter in the waste acid. If it does not meet the standard, continue to add the chemical dosage; otherwise, discharge the wastewater to the next process.

[0054] Step 5: The data analysis and management platform analyzes the data information obtained by the image monitoring device to determine whether the feeding of the screw metering feeder is normal.

[0055] The above solution provides a control method for the chemical dosing equipment. First, open the inlet electric valve and pump the fluorine-containing waste acid to be recycled from the production line into the reactor. Stop when the set liquid level is reached. Then, the sewage monitoring device uploads various parameter information of the waste acid to the data analysis and management platform for processing and analysis to determine the required amount of solid chemical to be added. Then, the PLC controller controls the feeding time of the screw metering feeder according to the required amount of solid chemical to carry out the feeding operation. During the entire chemical dosing process, the PLC controller controls the operation of the stirring device in the reactor to evenly mix the chemical and the waste acid. After the required amount of solid chemical has been added, continue to detect the fluoride ion parameter in the waste acid. If it does not meet the standard, continue to add the chemical dosage; otherwise, discharge the wastewater to the next process. Finally, the data analysis and management platform analyzes the data information obtained by the image monitoring device to determine whether the feeding of the screw metering feeder is normal. Through this operation, comprehensive analysis can be carried out based on parameters such as fluoride ion concentration, pH value, temperature, and interference ion concentration in the waste acid to accurately obtain the required amount of solid chemical to be added. It can achieve precise dosing without manual operation, reducing the waste of chemical dosage. At the same time, by detecting the fluoride ion concentration in the waste acid after adding the chemical, it can be detected in real time whether the treatment of the waste acid meets the standard. When it does not meet the standard, combined with parameters such as the chemical reaction efficiency coefficient and stirring duration, continue to add the chemical dosage to the waste acid, ensuring the treatment effect while reducing the chemical dosage. In addition, by analyzing the images and other information obtained by the image monitoring device, it can automatically judge the feeding situation of the screw metering feeder, verify whether the flow of the chemical is uniform during the conveying process, and once abnormal, give an alarm in time to prevent blockage or caking from affecting the dosing accuracy.

[0056] The method for determining the required amount of solid chemical to be added in Step 2 is: obtain the fluoride ion concentration in the waste acid , pH value , calcium ion concentration , interference ion concentration and the waste acid temperature value , and calculate the required amount of solid chemical through the formula ; ;

[0057] Among them, is the basic addition amount, is the optimal pH value, is the theoretical calcium ion requirement value, is the optimal temperature value, , is the total number of detected interfering ions, is the concentration of the i-th interfering ion, is the weight coefficient of the i-th interfering ion, and , is the reference value of the interfering ion concentration, is the pH deviation penalty coefficient, is the interfering ion influence coefficient, is the calcium ion saving coefficient, is the temperature compensation coefficient.

[0058] The above scheme provides a specific method for determining the required dosage of solid medicine. Generally speaking, the dosage of medicine to be put in is related to the concentration of fluoride ions contained. The greater the concentration, the more medicine dosage is required. And the dosage of medicine in the treatment process is related not only to the fluoride ion concentration but also to other parameters, such as the pH value and the size of the wastewater temperature. During the treatment process, the pH value and the wastewater temperature should be within a suitable range. If they are too large or too small, they will affect the dosage of medicine. Generally, in the treatment of fluoride-containing wastewater, the solid medicine will contain calcium ions to promote the treatment. If there are already calcium ions in the wastewater, the amount of externally added calcium salt can be reduced. When the calcium ions are insufficient, additional supplementation is required. At the same time, the more the concentration of other interfering ions that affect the treatment (such as , , etc.), the more solid medicine dosage needs to be increased to ensure the treatment efficiency. Therefore, obtaining the fluoride ion concentration , pH value , calcium ion concentration , interfering ion concentration and the wastewater temperature value , through the formula calculate the required dosage of solid medicine ; among them, is the basic addition amount, which is determined according to the minimum amount of medicine required to treat a unit concentration of fluoride, is the optimal pH value, is the theoretical calcium ion requirement value, is the optimal temperature value, is the reference value of the interfering ion concentration, all of which can be determined according to historical data and empirical data. The weight coefficient of each interfering ion is determined according to the severity of interference of each interfering ion, is the pH deviation penalty coefficient, is the interfering ion influence coefficient, is the calcium ion saving coefficient, is the temperature compensation coefficient, both of which can be determined according to the experimental comparison data; it can be known from the formula that the greater the difference between the obtained pH value and the optimal pH value, the greater the difference between the obtained temperature value and the optimal temperature, and the higher the concentration of interfering ions, the more the dosage of the medicine to be added needs to be increased. And the smaller the calcium ion concentration in the wastewater, the more the dosage of the medicine to be added needs to be increased correspondingly; in this way, the fluoride ion concentration, pH value, calcium ion concentration, interfering ion concentration and temperature value in the wastewater can be comprehensively analyzed to determine the final dosage of the medicine to be added, so as to achieve accurate dosing and avoid waste of the medicine.

[0059] In step three, the method for determining the feeding time of the screw metering feeder is: through the formula to obtain the feeding time ;

[0060] wherein, is the calibration coefficient, is the diameter of the feeder pipe, is the current operating frequency of the variable frequency motor, is the bulk density of the medicine to be added.

[0061] The above scheme provides a method for determining the feeding time of the screw metering feeder. By combining the diameter of the feeder pipe, the current operating frequency of the variable frequency motor, the bulk density of the medicine to be added, the calibration coefficient, etc., the feeding time can be calculated more accurately to achieve accurate feeding. And the calibration coefficient is calibrated through experiments, which takes into account the influence of factors such as pitch, filling efficiency, and mechanical friction on the feeding time, ensuring the accuracy and efficiency of medicine addition during the sewage treatment process.

[0062] The work process of step four is: detecting the fluoride ion concentration in the waste acid , and judging whether it reaches the target threshold concentration :

[0063] When the detected fluoride ion concentration in the waste acid reaches the target threshold concentration , it indicates that the treatment is up to standard, and the wastewater is discharged to the next process. If the detected fluoride ion concentration in the waste acid does not reach the target threshold concentration , then the secondary dosage of the medicine to be added is determined through the formula , and continuous dosing is carried out; wherein,

[0064] is the medicine reaction efficiency coefficient, is the waste acid viscosity attenuation factor, is the stirring duration, is the error compensation amount.

[0065] The above solution provides a method for adding the dosage of medicine for the second time when the treatment of fluorine-containing wastewater fails to meet the standard. First, detect the concentration of fluoride ions in the waste acid , and determine whether it reaches the target threshold concentration : When the concentration of fluoride ions in the detected waste acid reaches the target threshold concentration , it indicates that the treatment meets the standard, and the wastewater is discharged to the next process. If the concentration of fluoride ions in the detected waste acid does not reach the target threshold concentration , then determine the dosage of the second addition of medicine through the formula , and continue to add medicine; where is the medicine reaction efficiency coefficient, is the waste acid viscosity attenuation factor, is the error compensation amount, all of which can be determined according to the experimental comparison data , and is the stirring duration. In this way, comprehensive analysis can be carried out in combination with the medicine reaction efficiency, waste acid viscosity attenuation factor, etc., and the required dosage of medicine can be estimated more accurately, which can effectively improve the treatment effect of fluorine-containing wastewater

[0066] The method for judging whether the feeding of the screw metering feeder is normal in step five is as follows: Obtain an image information of the material every time, and perform graying, noise reduction, and binarization processing on the image to extract the material transmission area in the image

[0067] Divide the material transmission area into n sub-areas, and obtain the gray values of each sub-area , and at the same time, obtain the overall gray average value through the formula ;

[0068] Obtain the feeding coherence index through the formula ;

[0069] When , it is determined that the feeding of the screw metering feeder is abnormal

[0070] At the same time, when the screw metering feeder is operating normally, continuously obtain the coherence index of N pieces of image information, so as to formulate a curve function of the coherence index changing with the number of image sheets x ;

[0071] Obtain the feeding abnormality value through the formula ;

[0072] When , it is determined that the feeding of the screw metering feeder is abnormal​​​

[0073] Among them, is the set judgment threshold of the coherence index, is the set judgment threshold of abnormal feeding, is the maximum slope of is the minimum slope of is the slope reference value, which can be determined by experimental data, is the last obtained image.

[0074] The above solution provides a specific method for monitoring the feeding situation of the screw quantitative feeder. First, an image information of the material is obtained every time, and the image is grayscaled, denoised, and binarized to extract the material transmission area in the image. Then, the material transmission area is divided into n sub-areas, and the gray values of each sub-area are obtained , and at the same time, the overall gray average value is obtained through the formula , and finally, the feeding coherence index is obtained through the formula ; the gray value can represent the density situation of the material in each sub-area, and the coherence index represents a fluctuation situation of the material in the transmission area. Obviously, the smaller its value, the more uniform the distribution, indicating that the flow uniformity of the medicament during transportation is better. On the contrary, it indicates that the flow uniformity of the medicament during transportation is worse. Therefore, it is compared with the coherence index judgment threshold set according to experience. When , it indicates that the flow uniformity of the medicament during transportation is poor, then it is judged that the feeding of the screw quantitative feeder is abnormal, and an alarm is given in time. Although it is monitored that the screw quantitative feeder is operating normally, if the coherence index obtained under normal conditions is slowly increasing, or has been near the threshold all the time, it indicates that there is a potential abnormal situation. Therefore, in order to more accurately understand the feeding situation of the screw quantitative feeder, when the screw quantitative feeder is operating normally, the coherence indexes of N image information are continuously obtained to draw the curve function of the coherence index varying with the number of image sheets x, and the abnormal feeding value is obtained through the formula ; the formula represents the cumulative situation of the coherence index, while represents the change situation of the coherence index. Obviously, the larger the abnormal feeding value , the greater the possibility of potential abnormal phenomena existing in the feeding of the screw quantitative feeder. Therefore, it is compared with the preset abnormal feeding judgment threshold according to experience. When When it is like this, it indicates that there is a high possibility of abnormal phenomena during the feeding process of the screw metering feeder. To avoid the occurrence of subsequent abnormal phenomena, it is also determined that the feeding of the screw metering feeder is abnormal, and an alarm is given and adjusted in a timely manner to ensure the efficiency of the entire treatment process. Through this method, the image information obtained by the screw metering feeder during the transportation of the medicament can be analyzed to detect abnormal feeding phenomena or potential abnormal phenomena during the transportation process, and the uniformity of the flow of the medicament during the transportation can be verified. Once an abnormality occurs, an alarm is given in a timely manner to prevent blockage or caking from affecting the dosing accuracy.

[0075] The data analysis and management platform is also used to monitor the operating status of the dosing equipment. The monitoring method is as follows: During the cycle, obtain the number of times of abnormal feeding in each waste acid treatment batch of the dosing equipment ;

[0076] Through the formula obtain the status value ;

[0077] When it is determined that the operating status of the dosing equipment is abnormal;

[0078] Among them, is the set status judgment threshold, is the total number of waste acid treatment batches carried out during the cycle, and is the number of batches in which the number of abnormal feeding times in all treatment batches is greater than the average value.

[0079] The above technical solution provides a method for monitoring the operating status of the dosing equipment. First, during the formulated cycle, obtain the number of times of abnormal feeding in each waste acid treatment batch of the dosing equipment . Generally, the more the number of abnormal times, the worse the operating status of the equipment. Therefore, through the formula obtain the status value . The formula represents the fluctuation of the number of abnormal times of the dosing equipment under M treatment batches. The larger its value, the more unstable it is, and represents the proportion of the treatment batches in which the number of abnormal feeding times in M treatment batches is greater than the average value. Obviously, the larger its value, the greater the possibility of abnormal operating status of the dosing equipment. Therefore, compare it with the status judgment threshold set according to experience. When If so, it is determined that the operation status of the chemical dosing equipment is abnormal. In this way, the operation status of the chemical dosing equipment can be monitored, so as to perform maintenance in a timely manner, ensure the perfection of the chemical dosing equipment, and thus guarantee the continuity of the entire treatment process and the stability of the reuse efficiency.

[0080] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar ways to replace them. As long as they do not deviate from the concept of the invention or exceed the scope defined by this claims, they should all fall within the protection scope of the present invention.

Claims

1. Control method for variable-frequency dosing equipment of medicament for recycling fluorine-containing waste acid, including variable-frequency dosing equipment of medicament for recycling fluorine-containing waste acid, characterized in that, The device includes a screw metering feeder (1), a reaction kettle (2), a sewage monitoring device (3), an image monitoring device (4), a PLC controller, and a data analysis and management platform; The screw metering feeder (1) includes a variable-frequency motor (11), a screw conveyor shaft (12), a storage bin (13), and a discharge port (14). The discharge port (14) is connected to the reaction kettle (2). The image monitoring device (4) is installed at the discharge port (14). The sewage monitoring device (3) is installed inside the reaction kettle (2). A stirring device (21) is also installed inside the reaction kettle (2). The data analysis and management platform is connected to the chemical dosing equipment and the PLC controller through the Internet of Things. The PLC controller is used to control the operation of the screw metering feeder (1) according to the control instructions; The control method of the variable-frequency chemical dosing equipment for recycled medicament of fluorine-containing waste acid includes: Step 1, pump the fluorine-containing waste acid into the reaction kettle, stop when the set liquid level is reached, and obtain various parameter information of the waste acid through the sewage monitoring device; Step 2, upload the obtained various parameter information to the data analysis and management platform for processing and analysis to determine the required dosage of solid medicament; Step 3, according to the required dosage of solid medicament, the PLC controller controls the feeding time of the screw metering feeder to perform the feeding operation; Step 4, during the chemical dosing process, the PLC controller controls the operation of the stirring device in the reaction kettle. After the required dosage of solid medicament is added, continue to detect the fluorine ion parameter in the waste acid. If it does not meet the standard, continue to add the dosage of medicament. Otherwise, discharge the wastewater to the next process; Step 5, the data analysis and management platform analyzes the data information obtained by the image monitoring device to judge whether the feeding of the screw metering feeder is normal; The method for determining the required dosage of solid medicine in the second step is as follows: Obtain the fluoride ion concentration in the waste acid , pH value , calcium ion concentration , interfering ion concentration and the waste acid temperature value , and calculate the required dosage of solid medicine through the formula ; wherein, is the basic addition amount, is the optimal pH value, is the theoretical calcium ion demand value, is the optimal temperature value, , is the total number of detected interfering ions, is the concentration of the i-th interfering ion, is the weight coefficient of the i-th interfering ion, and , is the reference value of the interfering ion concentration, is the pH deviation penalty coefficient, is the interfering ion influence coefficient, is the calcium ion saving coefficient, is the temperature compensation coefficient.

2. The control method of the variable-frequency dosing equipment for the fluorine-containing waste acid recycling agent according to claim 1, characterized in that, The method for determining the feeding time of the screw metering feeder in Step 3 is: Obtained by the formula to obtain the feeding time ; Among them, is the calibration coefficient, is the pipe diameter of the feeder, is the current operating frequency of the variable-frequency motor, is the bulk density of the chemical agent being dispensed.

3. The control method of the variable-frequency dosing equipment for the fluorine-containing waste acid recycling agent according to claim 2, characterized in that, The workflow of Step 4 is: Detect the fluoride ion concentration in waste acid , and determine whether it reaches the target threshold concentration :[[]]END]] When the fluoride ion concentration in the detected waste acid reaches the target threshold concentration , it indicates that the treatment meets the standard, and the wastewater is discharged to the next process. If the fluoride ion concentration in the detected waste acid does not reach the target threshold concentration , then the secondary dosing amount is determined through the formula and continuous dosing is carried out; ​ Among them, is the reagent reaction efficiency coefficient, is the waste acid viscosity attenuation factor, is the stirring duration, is the error compensation amount.

4. The control method of the variable-frequency dosing equipment for the medicament for recycling fluorine-containing waste acid according to claim 3, characterized in that, The method for judging whether the feeding of the screw metering feeder is normal in Step 5 is: Every time, obtain the image information of a material, and perform grayscale conversion, noise reduction, and binarization on the image to extract the material transmission area in the image; Divide the material transmission area into n sub - areas and obtain the grayscale values of each sub - area , and at the same time through the formula obtain the overall average grayscale value ; Through the formula the coherence index of the feed is obtained ; When it is determined that the feeding of the spiral metering feeder is abnormal; Meanwhile, when the spiral quantitative feeder is operating normally, continuously obtain the coherence index of N pieces of image information, so as to formulate the curve function of the coherence index varying with the number of images x ; Through the formula the abnormal value of material feeding is obtained ; When it is determined that the feeding of the screw metering feeder is abnormal; Among them, is the set coherence index judgment threshold value, is the set abnormal feeding judgment threshold value, is the maximum slope of, is the minimum slope of, is the slope reference value, is the last obtained image.

5. The control method of the variable-frequency dosing device for the fluorine-containing waste acid recycling agent according to claim 4, characterized in that The data analysis and management platform is also used to monitor the operating status of the chemical dosing equipment. The monitoring method is: During the cycle, obtain the number of times of abnormal feeding under each waste acid treatment batch of the chemical dosing equipment ; Obtain the situation value through the formula to obtain the situation value ; When occurs, it is determined that the operation status of the chemical dosing equipment is abnormal; Wherein, is the set condition judgment threshold value, is the total number of batches of waste acid treatment carried out within a cycle, and is the number of batches in which the number of abnormal feeding times in all treatment batches is greater than the average value.

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