Integrated equipment for preparing sodium fluosilicate by resource utilization of photovoltaic wastewater

Abstract

The invention discloses integrated equipment for preparing sodium fluosilicate through photovoltaic wastewater resource utilization, and particularly relates to the field of photovoltaic wastewater, the integrated equipment comprises a filtering unit, a chemical adding unit, a reaction unit, a centrifugal unit and an online detection system, the filtering unit comprises a raw water tank and a precision filter, the raw water tank is connected with the precision filter through a pipeline, and the chemical adding unit is connected with the reaction unit through a pipeline; an online hydrofluoric acid concentration detector is arranged at the water outlet end of the precision filter; the online detection system comprises a fluorine ion detector, a pH meter module and a PLC (Programmable Logic Controller) control unit, and the PLC control unit is used for quantitatively conveying filtered wastewater to a reaction tank in the reaction unit through a water pump according to the detected hydrofluoric acid concentration. According to the equipment, efficient resource utilization of photovoltaic wastewater is realized through precise filtration, dosing and reaction control, and a sodium fluosilicate product is generated.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic wastewater, and more specifically, to an integrated device for preparing sodium fluorosilicate by resource utilization of photovoltaic wastewater. Background Art

[0002] Solar energy is the most abundant and widely distributed renewable resource on earth. With the advancement of technology and the reduction of costs, photovoltaic power generation has become the fastest-growing and largest renewable energy in China in recent years after wind power generation. China's photovoltaic industry scale, manufacturing and technology level are ranked first in the world. The production of photovoltaic cells and modules in the photovoltaic industry chain is an important component of the transformation from crystalline silicon raw materials to photovoltaic products.

[0003] As the photovoltaic industry grows and develops, the generation of three wastes also arises. Among them, the pollution control of high-concentration fluoride-containing wastewater is a persistent problem that the photovoltaic industry needs to solve. Fluorine is a trace element necessary for the human body, but long-term excessive intake of high-fluoride water will have serious adverse effects on the gastrointestinal tract, liver, kidneys, nervous system, muscles, reproductive and immune systems, and DNA structure, and even cause bone sclerosis, permanent disability and cancer. In addition to threatening human health, fluoride pollution also has serious harm to the ecological environment. Excessive fluoride content will inhibit soil nitrification and acid phosphatase activity, change the structure and pH of soil protozoan communities, and affect the normal growth of plants;

[0004] The treatment methods for fluoride-containing wastewater mainly include chemical precipitation, coagulation precipitation, adsorption and crystallization. In addition, there are membrane separation, ion exchange and electrocoagulation. At present, domestic photovoltaic cell manufacturers often use chemical precipitation and coagulation precipitation to purify water quality after mixing fluoride-containing wastewater from different sources. The most commonly used precipitant in the chemical precipitation method is calcium salt, such as lime, calcium chloride, calcium carbonate and carbide slag. Calcium salt has a good effect in removing fluoride, but the disadvantage in actual engineering is that the calcium fluoride formed by calcium salt and fluorine will be wrapped on the surface of calcium hydroxide, which is not conducive to the reaction. Completely carried out, resulting in a large amount of calcium salt addition (the amount is often 3 to 4 times the theoretical value), high sludge yield and complex composition, low calcium fluoride content, low reuse value, and simple chemical precipitation The effluent cannot meet the discharge standard, and generally requires a coagulant for deep defluorination. Commonly used inorganic coagulants are iron salts and aluminum salts, and organic flocculants are mostly polyacrylamide (PAM). The disadvantage of using aluminum salts is that it will introduce aluminum elements that are harmful to the human body and cause excessive chloride ions, while iron salts can only be carried out smoothly under higher pH conditions, resulting in increased water treatment costs;

[0005] In summary, fluorine-containing wastewater from photovoltaic cell production seriously threatens the lives of humans, animals, and aquatic organisms, and damages the ecological environment. It must be strictly controlled in accordance with national standards before being discharged into the water environment. The current method of combining chemical precipitation and coagulation precipitation is commonly used for fluorine-containing wastewater produced by photovoltaic cell production enterprises, but the sludge yield is high and the composition is complex, the calcium fluoride content is low, and it is difficult to reuse. It still cannot solve the problem of fluorine-containing sludge treatment and disposal, resulting in high operating costs. Summary of the invention

[0006] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides an integrated device for preparing sodium fluorosilicate by resource utilization of photovoltaic wastewater. Through precise filtration, dosing and reaction control, efficient resource utilization of photovoltaic wastewater is achieved to generate sodium fluorosilicate products. The online detection system ensures accurate monitoring of the concentrations of hydrofluoric acid and fluoride, making the dosing process more accurate and avoiding excessive or insufficient dosing, so as to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: an integrated device for preparing sodium fluorosilicate by resource utilization of photovoltaic wastewater, comprising a filtering unit, a dosing unit, a reaction unit, a centrifugal unit, and an online detection system.

[0008] The filtration unit includes a raw water tank and a precision filter, the raw water tank is connected to the precision filter through a pipeline, and an online hydrofluoric acid concentration detector is provided at the water outlet of the precision filter; the online detection system includes a fluoride ion detector, a pH meter module and a PLC control unit, and the PLC control unit quantitatively transports the filtered wastewater to the reaction tank in the reaction unit through a water pump according to the detected hydrofluoric acid concentration;

[0009] The dosing unit comprises a liquid silicon dioxide dosing box, a sodium chloride soaking tank and a sodium chloride solution dosing box, wherein the liquid silicon dioxide dosing box and the sodium chloride solution dosing box are respectively connected to the reaction tank through dosing metering pumps; the PLC control unit calculates the dosage of the liquid silicon dioxide and the sodium chloride solution according to the detected hydrofluoric acid concentration, and controls the dosing rate of the agent through the dosing metering pump;

[0010] The reaction unit comprises a reaction tank and a stirrer, and the wastewater containing hydrofluoric acid, liquid silicon dioxide and sodium chloride aqueous solution are sequentially transported to the reaction tank through pipelines and stirred by the stirrer;

[0011] The centrifugal unit comprises a centrifuge and a mother liquor tank. The centrifuge is connected to the reaction tank through a pipeline and is used for centrifugally separating the mixture after the reaction is completed. The obtained solid sodium fluorosilicate is collected as a product. The mother liquor after centrifugation is transported to the mother liquor tank through a pipeline. The mother liquor tank is provided with an online fluoride ion concentration detector. When the fluoride concentration in the mother liquor is ≤1000ppm, the mother liquor is transported to the fluoride-containing wastewater treatment system for further treatment. When the fluoride concentration in the mother liquor is greater than 1000ppm, the mother liquor is returned to the raw water tank for re-treatment.

[0012] In a preferred embodiment, it also includes an optimization system for reducing the probability of the mother liquor being returned to the raw water tank for reprocessing, and the optimization system includes a data acquisition module, a state determination module, an optimization control module and a feedback learning module;

[0013] The data acquisition module is used to monitor various parameters in the system in real time and provide data support for subsequent status judgment and optimization control;

[0014] The state identification module determines the current state of the system based on the collected data and triggers the corresponding control strategy. The states include normal state, warning state and overload protection state.

[0015] The optimization control module transmits corresponding signals to the online detection system according to different states, and the PLC control unit of the online detection system automatically adjusts the dosage, dosage rate, and reaction time parameters to reduce the probability of reprocessing;

[0016] The feedback learning module is used to record and analyze historical data, and continuously optimize the system's judgment logic and control strategy through machine learning.

[0017] In a preferred embodiment, the preset value 1 is set as P1: used to determine the lower limit of the hydrofluoric acid concentration;

[0018] The second preset value is proposed to be P2: used to determine the upper limit of hydrofluoric acid concentration;

[0019] The proposed preset value three is P3: used to determine the lower limit of the ambient temperature;

[0020] The proposed preset value 4 is P4: used to determine the upper limit of the wastewater flow rate;

[0021] The fourth preset value is proposed to be P5: used to determine the upper limit or variation range of the ambient humidity;

[0022] The proposed reaction temperature is T: represents the temperature in the reaction tank;

[0023] The proposed threshold value 1 is T1: used to determine the warning value of fluoride concentration;

[0024] The proposed threshold value 2 is T2: used to determine the upper limit of fluoride concentration;

[0025] The proposed threshold value three is T3: used to determine the safe upper limit of the device temperature;

[0026] The proposed threshold value four is T4: used to determine the safe upper limit of current consumption;

[0027] The proposed preset range 1 is R1: used to determine the safe range of the liquid level in the reaction tank;

[0028] The proposed preset range 2 is R2: the stable range of stirring speed;

[0029] The proposed standard deviation threshold is σ1: used to determine the standard deviation range of the dosing rate;

[0030] The proposed standard deviation threshold σ2 of the stirring speed: represents the allowable fluctuation range of the stirring speed;

[0031] The proposed maximum threshold value 1 is M1: used to determine the maximum limit of the dosing rate;

[0032] The proposed fluctuation threshold is δ1: it indicates the fluctuation range of fluoride concentration allowed by the system. If it is less than this value, it means that the system is running smoothly;

[0033] In normal state, including the judgment of dosage and dosage rate:

[0034] If the hydrofluoric acid concentration C HF The wastewater flow rate V w Within the preset range R1, and the dosing rate Standard Deviation If the value is less than the standard deviation threshold -σ1, the system maintains the current dosage and dosage rate and remains in the normal state;

[0035] If the hydrofluoric acid concentration C HF Exceeds the preset value P2, or the wastewater flow V w Exceeds the preset value R4, or the dosing rate The maximum value of If it exceeds the maximum threshold value M1, it switches to the alert state;

[0036] In the general state, there are checks on parameter stability:

[0037] If the fluoride concentration fluctuates ΔC F The mean is less than the set fluctuation threshold δ1, and the reaction tank level L tank Within the preset range R1, and the stirring speed R stir Within the stable range R2, the system continues to operate according to the current parameters and remains in a normal state;

[0038] If the stirring speed R stir Variance Exceeds the set standard deviation threshold σ2, or the stirring speed R stir If the reaction temperature exceeds the stable range R2 and approaches the upper temperature limit T3 of the equipment, the system needs to reduce the stirring speed or extend the reaction time and switch to the alert state.

[0039] In normal state, the prediction of effluent quality includes:

[0040] If the effluent fluoride concentration predicted by historical data and current input parameters is Approaching the warning threshold T1, and the actual deviation ΔC F If it is within the normal range, the system will pre-adjust the dosage or reaction time to continue to maintain the normal state;

[0041] If the predicted value of effluent fluoride concentration is Below the warning threshold T1, and the uniformity of the drug delivery H stir Keep stable, reduce the dosage of the system and maintain it in normal state.

[0042] In a preferred embodiment, in the alert state, the dosage adjustment is included:

[0043] If the current fluoride concentration C F Exceeds the warning threshold T1 but is lower than the upper threshold T2, and the dosage The coefficient of variation If it is within the normal range, the system needs to adjust the dosage to maintain the reaction effect and continue to remain in the alert state;

[0044] If the fluoride concentration C F Exceeds the upper threshold T2, or the ambient temperature T env Or humidity H env Changes occur and the system enters the overload protection state;

[0045] In the alert state, the environmental parameters are linked to control:

[0046] If the pH value and temperature T deviate from the optimal operating range at the same time, and the ambient temperature T env Or humidity H env If there is a fluctuation, the system starts linkage control, adjusts the amount of acid and alkali added or the temperature control measures, and maintains it in an alert state;

[0047] If the environmental parameter fluctuation exceeds the set threshold value P3 or P5 and causes the system to operate abnormally, the system switches to the overload protection state;

[0048] In the alert state, including real-time monitoring and feedback:

[0049] If the stirring speed R is monitored in real time stir Fluctuations occur, and the dosing rate If the control accuracy decreases, or the stirring speed exceeds the stable range R2, the system needs to dynamically adjust the stirring speed or dosing rate to continue to maintain the alert state;

[0050] If the fluoride concentration in the effluent is The real-time detection value is close to the upper threshold T2, and the reaction time T r It is close to the maximum allowable value. The system prolongs the reaction time or slows down the dosing rate to avoid the water quality not meeting the standard and switches to the overload protection state.

[0051] In a preferred embodiment, in the overload protection state, load distribution and relief are included:

[0052] If the current wastewater flow V w Exceeds the preset value P4, and the reaction tank liquid level L tank If the safety range R1 is exceeded, the system needs to automatically adjust the water inlet flow and divert part of the wastewater to the backup treatment unit, and the system remains in an overload protection state;

[0053] If the device temperature T aevice and current consumption I device At the same time, the safety thresholds T3 and T4 are exceeded, and the device vibrates V vibration Display abnormality, that is, exceeding the vibration standard, the system needs to immediately reduce the load or suspend some operations and continue to maintain the overload protection state;

[0054] In the overload protection state, it includes equipment protection and fault prevention:

[0055] If the equipment running time T runtime Exceeding the preset time P runtime , and the equipment wear state W is detected wear Increase, the system starts the equipment maintenance program to prevent the equipment from continuing to run under high load, causing failures;

[0056] If the device's self-test result is D diagnosis Indicates that there is a potential failure risk and the failure probability P fault Increase, the system arranges preventive maintenance or repair, and continues to maintain the overload protection state;

[0057] In the overload protection state, it includes self-checking and repairing:

[0058] If the device health status is H device Decreasing, and the self-check program detects an abnormality, the system needs to immediately trigger the self-check and repair program and continue to maintain the overload protection state;

[0059] If the fluctuation range of the equipment's operating parameters is ΔP device If it exceeds the normal range and the operation history shows that similar fluctuations have caused faults, the system needs to issue early warnings and adjust parameters to prevent the fault from recurring and continue to maintain the overload protection state.

[0060] Technical effects and advantages of the present invention:

[0061] 1. The equipment realizes efficient resource utilization of photovoltaic wastewater and generates sodium fluorosilicate products through precise filtration, dosing and reaction control. The online detection system ensures accurate monitoring of hydrofluoric acid and fluoride concentrations, making the dosing process more accurate, avoiding excessive or insufficient dosing, and improving reaction efficiency. Through centrifugal separation technology, solid sodium fluorosilicate can be effectively separated to ensure product quality. The mother liquor recycling treatment mechanism reduces resource waste, further improves wastewater treatment efficiency, and realizes the optimization of clean production and resource recycling;

[0062] 2. Through the state judgment logic of the state judgment module, the preset values ​​and thresholds are clarified to monitor the key parameters such as hydrofluoric acid concentration, flow, temperature, humidity, etc. in real time to ensure that the system can accurately judge the current state (normal, warning, overload); when it is detected that the parameters are out of the set range, the system can automatically switch the state and make fine adjustments such as dosing rate, stirring speed, load distribution, etc. to ensure stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 The figure is a flow chart of the fluorine recovery process of the present invention.

[0064] Figure 2 For the present invention Figure 1 Enlarged view of the left half of the structure.

[0065] Figure 3 For the present invention Figure 1 Enlarged view of the right half of the structure.

[0066] Figure 4 It is a schematic diagram of the plan layout of fluorine recovery of the present invention.

[0067] Figure 5 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] Refer to the instruction manual Figure 1-5 An integrated device for preparing sodium fluorosilicate by resource utilization of photovoltaic wastewater according to an embodiment of the present invention comprises a filtering unit, a dosing unit, a reaction unit, a centrifugal unit, and an online detection system.

[0070] The filtration unit includes a raw water tank and a precision filter. The raw water tank is connected to the precision filter through a pipeline. The water outlet of the precision filter is provided with an online hydrofluoric acid concentration detector. The online detection system includes a fluoride ion detector, a pH meter module and a PLC control unit. The PLC control unit automatically transports the filtered wastewater to the reaction tank in the reaction unit in a quantitative manner through a water pump according to the detected hydrofluoric acid concentration.

[0071] The dosing unit includes a liquid silica dosing box, a sodium chloride soaking tank and a sodium chloride solution dosing box. The liquid silica dosing box and the sodium chloride solution dosing box are connected to the reaction tank through dosing metering pumps respectively; the PLC control unit automatically calculates the dosage of liquid silica and sodium chloride solution according to the detected hydrofluoric acid concentration, and controls the dosing rate of the agent through the dosing metering pump;

[0072] The reaction unit includes a reaction tank and a stirrer. The wastewater containing hydrofluoric acid, liquid silicon dioxide and sodium chloride aqueous solution are sequentially transported to the reaction tank through pipelines and stirred and reacted under the action of the stirrer.

[0073] The centrifugal unit includes a centrifuge and a mother liquor tank. The centrifuge is connected to the reaction tank through a pipeline and is used to centrifugally separate the mixture after the reaction is completed. The obtained solid sodium fluorosilicate is collected as a product. The mother liquor after centrifugation is transported to the mother liquor tank through a pipeline. The mother liquor tank is provided with an online fluoride ion concentration detector. When the fluoride concentration in the mother liquor is ≤1000ppm, the mother liquor is transported to the fluoride-containing wastewater treatment system for further treatment. When the fluoride concentration in the mother liquor is >1000ppm, the mother liquor is returned to the raw water tank for re-treatment.

[0074] It also includes an optimization system for reducing the probability of the mother liquor being returned to the raw water tank for reprocessing, the optimization system including a data acquisition module, a state determination module, an optimization control module and a feedback learning module;

[0075] The data acquisition module is used to monitor the key parameters of the system in real time and provide data support for subsequent status judgment and optimization control;

[0076] The state identification module determines the current state of the system based on the collected data and triggers the corresponding control strategy. The states include normal state, warning state and overload protection state.

[0077] The optimization control module transmits corresponding signals to the online detection system according to different states. The PLC control unit of the online detection system automatically adjusts the parameters such as the dosage, dosage rate, reaction time, etc. to optimize the treatment effect and reduce the probability of re-treatment.

[0078] The feedback learning module is used to record and analyze historical data, and continuously optimize the system's judgment logic and control strategy through machine learning.

[0079] The proposed preset value 1 is P1: used to determine the lower limit of hydrofluoric acid concentration;

[0080] The second preset value is proposed to be P2: used to determine the upper limit of hydrofluoric acid concentration;

[0081] The proposed preset value three is P3: used to determine the lower limit of the ambient temperature;

[0082] The proposed preset value 4 is P4: used to determine the upper limit of the wastewater flow rate;

[0083] The fourth preset value is proposed to be P5: used to determine the upper limit or variation range of the ambient humidity;

[0084] The proposed reaction temperature is T: represents the temperature in the reaction tank;

[0085] The proposed threshold value 1 is T1: used to determine the warning value of fluoride concentration;

[0086] The proposed threshold value 2 is T2: used to determine the upper limit of fluoride concentration;

[0087] The proposed threshold value three is T3: used to determine the safe upper limit of the device temperature;

[0088] The proposed threshold value four is T4: used to determine the safe upper limit of current consumption;

[0089] The proposed preset range 1 is R1: used to determine the safe range of the liquid level in the reaction tank;

[0090] The proposed preset range 2 is R2: the stable range of stirring speed;

[0091] The proposed standard deviation threshold is σ1: used to determine the standard deviation range of the dosing rate;

[0092] The proposed standard deviation threshold σ2 of the stirring speed: represents the allowable fluctuation range of the stirring speed;

[0093] The proposed maximum threshold value 1 is M1: used to determine the maximum limit of the dosing rate;

[0094] The proposed fluctuation threshold is δ1: it indicates the fluctuation range of fluoride concentration allowed by the system. If it is less than this value, it means that the system is running smoothly;

[0095] In normal state, including the judgment of dosage and dosage rate:

[0096] If the hydrofluoric acid concentration C HF The wastewater flow rate V w Stable within the preset range R1, and the dosing rate Standard Deviation When the standard deviation is less than the threshold value of -σ1, the system maintains the current dosage and dosage rate and remains in a normal state; stability means that the wastewater flow has no obvious fluctuations and the standard deviation of the dosage rate is within an acceptable range, indicating that the dosage process is stable;

[0097] If the hydrofluoric acid concentration C HF Exceeds the preset value P2, or the wastewater flow V w Exceeds the preset value P4, or the dosing rate The maximum value of If the maximum value threshold M1 is exceeded, the system switches to the alert state. Exceeding the upper limit means that the hydrofluoric acid concentration and flow rate are higher than the maximum value of the process design, indicating that the system is in a high-load state. At this time, the dosage needs to be increased to ensure the treatment effect.

[0098] In the general state, there are checks on parameter stability:

[0099] If the fluoride concentration fluctuates ΔC F The mean is less than the set fluctuation threshold δ1, and the reaction tank level L tank Within the preset range R1, it means that the liquid level has not changed significantly and is maintained at the designed level, and the stirring speed R stir Within the stable range R2, the system continues to operate according to the current parameters and remains in a normal state; the fluctuation threshold is the range of fluoride concentration variation allowed by the system. If it is less than this range, it means that the system is running smoothly, and the liquid level is within the design range, which indicates that the reaction conditions are stable;

[0100] If the stirring speed R stir Variance Exceeds the set standard deviation threshold σ2, or the stirring speed R stir If the reaction temperature exceeds the stable range R2 and approaches the upper temperature limit T3 of the equipment, the system needs to lower the stirring speed or extend the reaction time and switch to the warning state to prevent overreaction or overheating of the equipment. If the variance exceeds the standard deviation threshold, it means that the fluctuation of the stirring speed exceeds the allowable range, which may cause uneven reaction. If the temperature approaches the upper limit, it is necessary to prevent the equipment from overloading.

[0101] In normal state, the prediction of effluent quality includes:

[0102] If the effluent fluoride concentration predicted by historical data and current input parameters is Approaching the warning threshold T1, and the actual deviation ΔC F If it is within the normal range, the system will pre-adjust the dosage or reaction time to continue to maintain the normal state; the approaching warning threshold means that the fluoride concentration in the effluent is close to the maximum allowable value set by the process. The small deviation between the predicted and actual data indicates that the prediction is reliable;

[0103] If the predicted value of effluent fluoride concentration is Far below the warning threshold T1, and the uniformity of the drug delivery H stir If it remains stable, it means there is no significant fluctuation. The system can appropriately reduce the dosage to save resources and maintain it in a normal state. If it is far below the warning value, it means that the effluent quality is good. If the uniformity of the reagent is stable, it means that the reaction is uniform and it is suitable to reduce the dosage.

[0104] The switching logic in the normal state includes:

[0105] Switching from normal state to alert state: When the system detects that parameters such as hydrofluoric acid concentration, wastewater flow, stirring speed or effluent quality exceed the set safety range, the system immediately enters the alert state and starts more precise control and monitoring;

[0106] Maintain normal state: If all parameters are within the normal range and do not exceed the set fluctuation threshold, the system remains in the normal state without switching;

[0107] Buffer status:

[0108] If it is detected that the parameter is near the boundary value and it is difficult to clearly determine whether the state needs to be switched, the system enters the buffer state, further collects and analyzes data before deciding to switch.

[0109] In the alert state, including fine dosing adjustments:

[0110] If the current fluoride concentration C F Exceeds the warning threshold T1 but is lower than the upper threshold T2, and the dosage The coefficient of variation If it is within the normal range, it means that the dosing process is consistent. The system needs to make fine dosing adjustments to maintain the reaction effect and continue to remain in a state of alert to ensure sufficient reaction. If the coefficient of variation is within the normal range, it means that the fluctuation of the dosing amount is within the controllable range. Although the fluoride concentration is close to the upper limit, the reaction can still be controlled by finely adjusting the dosing amount. The coefficient of variation is used to measure the stability of the dosing process, especially for liquid silica. The coefficient of variation is used to evaluate the fluctuation of the dosing process by calculating the ratio of the standard deviation of the dosing amount to its mean. This indicator is dimensionless and can reflect the relative fluctuation range of the dosing amount. In the operation of the system, if the coefficient of variation is Being within the preset normal range means that the fluctuation of the dosing process is small, the dosage is kept consistent in each reaction, and the stability of the system reaction is high. At this time, although the fluoride concentration C F It may be close to the set upper threshold T2, but because the dosage is stable, the reaction can still be kept fully carried out through fine adjustment, and the system can continue to operate according to the current parameters. However, if the coefficient of variation If the value is beyond the normal range, it indicates that the dosage fluctuates greatly, and there may be large differences between different batches, resulting in insufficient reaction or inconsistent effect. Especially when the fluoride concentration is close to the upper threshold T2, the instability of the dosage may cause the treatment effect to decline or fail. Therefore, the system needs to make fine adjustments to the dosage according to the change of the coefficient of variation to ensure that the reaction can continue to maintain the best state and avoid the risk of treatment failure. In summary, the coefficient of variation It is a key control indicator in the system. By monitoring the consistency of the dosing process, it can help the system adjust the operation strategy in time under high load or high risk conditions to maintain the stability and effect of the reaction process. The coefficient of variation is equal to the standard deviation divided by the mean. The standard deviation reflects the degree of dispersion of the data, and the mean reflects the central position of the data.

[0111] If the fluoride concentration C F Exceeds the upper threshold T2, or the ambient temperature T env Or humidity H env The system enters the overload protection state; in addition, the ambient temperature T env Significant changes: When the temperature T env A certain percentage of the operating range is exceeded, such as more than 5% or a set temperature change threshold ΔT is exceeded env , which is defined as a significant change. For example, if the normal operating temperature range of the system is 20℃ to 30℃, then a temperature change of more than 1.5℃ can be considered a significant change; ambient humidity H env Significant changes: When the humidity H env A certain percentage outside the normal operating range, such as more than 10% or humidity changes exceeding the set humidity change threshold ΔH ∈nv , which is defined as a significant change. For example, if the normal range of humidity is 50% to 70%, a humidity change of more than 5% can be considered a significant change;

[0112] In the alert state, the environmental parameters are linked to control:

[0113] If the pH value and temperature T deviate from the optimal operating range at the same time, and the ambient temperature T env Or humidity H env If there are fluctuations, the system will start linkage control, adjust the amount of acid and alkali added or the temperature control measures, and maintain an alert state to ensure that the reaction conditions return to normal; deviation from the optimal operating range means that multiple key parameters have problems at the same time, and fluctuations in environmental conditions may aggravate these problems, so linkage adjustments are required to restore normal operating conditions;

[0114] If the environmental parameter fluctuation exceeds the set threshold value P3 or P5 and causes the system to operate abnormally, the system switches to the overload protection state;

[0115] Alternatively, if dissolved oxygen O diss The level is below the standard and the wastewater flow V w The flow rate fluctuates and is obviously unstable, which means that the flow rate fluctuates greatly. The system needs to adjust the ventilation device or ventilation equipment to ensure the stability of the reaction environment. Below the standard means insufficient dissolved oxygen, which may affect the reaction. Unstable flow indicates that the processing conditions fluctuate. At this time, the ventilation needs to be adjusted to ensure oxygen supply and smooth reaction.

[0116] In the alert state, including real-time monitoring and feedback:

[0117] If the stirring speed R is monitored in real time stir Fluctuations occur, that is, exceeding the preset stability standard, and the dosing rate If the control accuracy decreases, or the stirring speed exceeds the stable range R2, the system needs to dynamically adjust the stirring speed or dosing rate and continue to maintain the alert state to ensure that the treatment effect is not affected; fluctuations exceeding the standard indicate that there is a problem in the stirring process, and a decrease in control accuracy means that the dosing is not accurate enough, which may affect the consistency of the reaction;

[0118] If the fluoride concentration in the effluent is The real-time detection value is close to the upper threshold T2, and the reaction time T r It is close to the maximum allowable value. The system prolongs the reaction time or slows down the dosing rate to avoid the effluent quality not meeting the standard and switches to the overload protection state. Approaching the upper limit threshold means that the treatment process is close to failure. Prolonging the reaction time or slowing down the dosing rate can ensure the completion of the reaction and improve the effluent quality.

[0119] The state switching logic in the alert state includes:

[0120] Switching from the warning state to the overload protection state: When the system detects that the fluoride concentration or environmental parameters exceed the warning range in the warning state and may cause system failure, the system immediately switches to the overload protection state.

[0121] Switching from the alert state back to the normal state: If the fluoride concentration is reduced to below the alert threshold through adjustment and control, and the environmental conditions return to normal, the system can switch back to the normal state.

[0122] Buffer state: If the system detects that the parameters are close to the upper and lower limits and is unsure whether further switching is required, the system enters the buffer state and continues to collect and analyze data before deciding whether to continue the alert state or switch back to the normal state.

[0123] In the overload protection state, load distribution and relief are included:

[0124] If the current wastewater flow V w Exceeds the preset value P4, and the reaction tank liquid level L tank If the safety range R1 is exceeded, the system needs to automatically adjust the water inlet flow rate and divert part of the wastewater to the backup treatment unit, and the system remains in an overload protection state; if the system design load is exceeded, it means that the system's processing capacity exceeds its capacity, and the liquid level exceeds the safety range, it means that the reaction tank may not be able to accommodate more wastewater and needs to be diverted for treatment;

[0125] If the device temperature T device and current consumption I device At the same time, the safety thresholds T3 and T4 are exceeded, and the device vibrates V vibration If the display is abnormal, that is, it exceeds the vibration standard, the system needs to immediately reduce the load or suspend some operations and continue to maintain the overload protection state to prevent equipment damage or failure; exceeding the safety threshold means that the equipment is in a dangerous state, and abnormal vibration may indicate equipment failure, and immediate measures must be taken to avoid further damage;

[0126] In the overload protection state, it includes equipment protection and fault prevention:

[0127] If the equipment running time T runtime Exceeding the preset time P runtime , and the equipment wear state W is detected wear If the load increases significantly, the system starts the equipment maintenance procedure to prevent the equipment from continuing to run under high load, which may cause failures. If the preset time is exceeded, it means that the equipment has been running for a long time and may be in a fatigue state. Increased wear further increases the risk of failure and requires timely maintenance.

[0128] If the device's self-test result is D diagnosis Indicates that there is a potential failure risk and the failure probability P fault If the failure probability increases, the system will arrange preventive maintenance or repair in advance and continue to maintain the overload protection state to prevent equipment failure from affecting production; the existence of potential failure risk means that there may be problems with the equipment, and the increased failure probability indicates that the problem may be about to occur and needs to be handled in advance;

[0129] In the overload protection state, it includes self-checking and repairing:

[0130] If the device health status is H device If the health status decreases and the self-check program detects an abnormality, the system needs to immediately trigger the self-check and repair program and continue to maintain the overload protection state to prevent the expansion of potential faults and affect system operation. The decline in health status means that the device function may be degraded, and the self-check detection abnormality needs to be repaired immediately to prevent the problem from worsening;

[0131] If the fluctuation range of the equipment's operating parameters is ΔP device If the fluctuation is beyond the normal range and the operation history shows that similar fluctuations have caused faults before, the system needs to issue early warning and adjust parameters to prevent the fault from recurring and continue to maintain the overload protection state; if the fluctuation is beyond the normal range, it means that the equipment is unstable. Historical data supports that such fluctuations may cause faults and require early intervention;

[0132] In the overload protection state, dynamic learning and parameter updating are also included:

[0133] If the overload status data D overload The system performance degrades under high load and the model accuracy is A accuracy If the performance is lower than expected, the system needs to update parameter settings by learning historical data, optimize future load management strategies, and continue to maintain the overload protection state; performance degradation indicates that the system does not operate well under overload, and the model accuracy that is lower than expected needs to be optimized by updating parameters;

[0134] If the data update frequency F update If the update frequency is too low, the system will be delayed in response. The system needs to increase the frequency of data collection and model updates to improve the timeliness of prediction and adjustment and continue to maintain the overload protection state. If the update frequency is too low, the system cannot adapt to new data in time, resulting in delayed response. The data processing frequency needs to be accelerated.

[0135] The state switching logic of the overload protection state includes:

[0136] Switching from overload protection state to warning state: When the system is in overload protection state, after reducing load, diverting or suspending some operations, the system can gradually switch back to the warning state after detecting that the device temperature, current consumption and flow rate have returned to a safe range;

[0137] Recovering from overload protection state to normal state: If the system is in overload protection state, after a series of adjustments, all parameters (such as wastewater flow, temperature, current, etc.) are restored to the normal range and remain stable, the system can be switched back to normal state;

[0138] Fail-safe mode: If the system is detected to be unable to recover in the overload protection state and there is a risk of potential equipment failure, the system enters fail-safe mode, giving priority to equipment and system safety, which may trigger an emergency shutdown or manual intervention.

[0139] The following further explanations are needed for the plan:

[0140] The filtration unit includes a raw water tank and a precision filter. The raw water tank is connected to the precision filter. An online hydrofluoric acid concentration detector is provided for the outlet water of the precision filtration unit. The PLC control unit automatically transports the outlet water of the precision filter to the reaction tank of the reaction unit in a quantitative manner through a water pump.

[0141] The dosing unit includes a liquid silica dosing box, a sodium chloride soaking tank and a sodium chloride solution dosing box. The raw liquid silica is stored in the dosing box, equipped with a dosing metering pump, and connected to the reaction unit. According to the results of the online hydrofluoric acid concentration detector of the filtration unit, the online detection system automatically calculates the dosage of liquid silica, and the liquid silica is quantitatively and flow-rately added into the reaction tank of the reaction unit through the dosing metering pump.

[0142] Solid sodium chloride is prepared into sodium chloride aqueous solution in the medicine soaking tank in advance according to the proportion, and stored in the sodium chloride aqueous solution dosing box, equipped with a dosing metering pump, and connected to the reaction unit. According to the results of the online hydrofluoric acid concentration detector of the filtration unit, the online detection system automatically calculates the dosage of liquid silica, and the sodium chloride aqueous solution is quantitatively and flow-rately fed into the reaction tank of the reaction unit through the dosing metering pump.

[0143] The reaction unit comprises a reaction tank and a stirrer. Wastewater containing hydrofluoric acid, liquid silicon dioxide and sodium chloride aqueous solution are sequentially put into the reaction tank while being stirred.

[0144] The centrifugal unit includes a centrifuge and a mother liquor tank, which are connected to the reaction unit. The reaction completed liquid is transported from the reaction unit to the centrifuge through a pump for centrifugal drying. The solid is packaged as the product sodium fluorosilicate. The centrifuged mother liquor is transported to the mother liquor tank. The mother liquor tank is equipped with an online fluoride ion concentration detector. The fluoride concentration of the mother liquor is ≤1000ppm. It enters the subsequent fluoride wastewater treatment system as fluoride-containing wastewater. The mother liquor with a fluoride concentration greater than 1000ppm is transported back to the original water tank for further treatment.

[0145] Among them, the integrated equipment for resource utilization of 10 tons / day hydrofluoric acid wastewater to prepare sodium fluorosilicate, refer to the process flow chart and the internal layout of the integrated equipment attached to the specification, that is, Figure 1-4 ,in Figure 2 and Figure 3 yes Figure 1 The left and right parts of the enlarged picture are to prevent unclear reading;

[0146] The advantages of the present invention are:

[0147] When treating low concentration of hydrofluoric acid, sodium fluorosilicate can be recycled as long as the concentration of hydrofluoric acid is 1%; the integrated equipment occupies a small area and has a short treatment process; the number and quantity of reagents added are small, the operating cost is low, and the overall efficiency is high; PLC automatic control is easy to operate;

[0148] In the present invention, the process of recovering sodium fluorosilicate from hydrofluoric acid wastewater is concentrated in an integrated device, which occupies a small area and recovers more than 90% of fluorine, thereby achieving efficient fluorine removal, energy saving and cost reduction;

[0149] Through the PLC control unit and the online hydrofluoric acid detector and fluoride ion detector, the system can be fully automatically controlled, accurately calculate and control the feeding, and greatly reduce operating manpower.

[0150] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An integrated device for preparing sodium fluorosilicate by resource utilization of photovoltaic wastewater, comprising a filtration unit, a dosing unit, a reaction unit, a centrifugal unit, and an online detection system, characterized in that: The filtration unit includes a raw water tank and a precision filter, the raw water tank is connected to the precision filter through a pipeline, and an online hydrofluoric acid concentration detector is provided at the water outlet of the precision filter; the online detection system includes a fluoride ion detector, a pH meter module and a PLC control unit, and the PLC control unit quantitatively transports the filtered wastewater to the reaction tank in the reaction unit through a water pump according to the detected hydrofluoric acid concentration; The dosing unit comprises a liquid silicon dioxide dosing box, a sodium chloride soaking tank and a sodium chloride solution dosing box, wherein the liquid silicon dioxide dosing box and the sodium chloride solution dosing box are respectively connected to the reaction tank through dosing metering pumps; the PLC control unit calculates the dosage of the liquid silicon dioxide and the sodium chloride solution according to the detected hydrofluoric acid concentration, and controls the dosing rate of the agent through the dosing metering pump; The reaction unit comprises a reaction tank and a stirrer, and the wastewater containing hydrofluoric acid, liquid silicon dioxide and sodium chloride aqueous solution are sequentially transported to the reaction tank through pipelines and stirred by the stirrer; The centrifugal unit comprises a centrifuge and a mother liquor tank. The centrifuge is connected to the reaction tank through a pipeline and is used for centrifugally separating the mixture after the reaction is completed. The obtained solid sodium fluorosilicate is collected as a product. The mother liquor after centrifugation is transported to the mother liquor tank through a pipeline. The mother liquor tank is provided with an online fluoride ion concentration detector. When the fluoride concentration in the mother liquor is ≤1000ppm, the mother liquor is transported to the fluoride-containing wastewater treatment system for further treatment. When the fluoride concentration in the mother liquor is greater than 1000ppm, the mother liquor is returned to the raw water tank for re-treatment.

2. The integrated equipment for preparing sodium fluorosilicate by resource utilization of photovoltaic wastewater according to claim 1, characterized in that: It also includes an optimization system for reducing the probability of the mother liquor being returned to the raw water tank for reprocessing, the optimization system including a data acquisition module, a state determination module, an optimization control module and a feedback learning module; The data acquisition module is used to monitor various parameters in the system in real time and provide data support for subsequent status judgment and optimization control; The state identification module determines the current state of the system based on the collected data and triggers the corresponding control strategy. The states include normal state, warning state and overload protection state. The optimization control module transmits corresponding signals to the online detection system according to different states, and the PLC control unit of the online detection system automatically adjusts the dosage, dosage rate, and reaction time parameters to reduce the probability of reprocessing; The feedback learning module is used to record and analyze historical data, and continuously optimize the system's judgment logic and control strategy through machine learning.

3. The integrated equipment for preparing sodium fluorosilicate by resource utilization of photovoltaic wastewater according to claim 2, characterized in that: The proposed preset value 1 is P1: used to determine the lower limit of hydrofluoric acid concentration; The second preset value is proposed to be P2: used to determine the upper limit of hydrofluoric acid concentration; The proposed preset value three is P3: used to determine the lower limit of the ambient temperature; The proposed preset value 4 is P4: used to determine the upper limit of the wastewater flow rate; The fourth preset value is proposed to be P5: used to determine the upper limit or variation range of the ambient humidity; The proposed reaction temperature is T: represents the temperature in the reaction tank; The proposed threshold value 1 is T1: used to determine the warning value of fluoride concentration; The proposed threshold value 2 is T2: used to determine the upper limit of fluoride concentration; The proposed threshold value three is T3: used to determine the safe upper limit of the device temperature; The proposed threshold value four is T4: used to determine the safe upper limit of current consumption; The proposed preset range 1 is R1: used to determine the safe range of the liquid level in the reaction tank; The proposed preset range 2 is R2: the stable range of stirring speed; The proposed standard deviation threshold is σ1: used to determine the standard deviation range of the dosing rate; The proposed standard deviation threshold σ2 of the stirring speed: represents the allowable fluctuation range of the stirring speed; The maximum threshold value 1 is proposed to be M1: used to determine the maximum limit of the dosing rate; The proposed fluctuation threshold is δ1: it indicates the fluctuation range of fluoride concentration allowed by the system. If it is less than this value, it means that the system is running smoothly; In normal state, including the judgment of dosage and dosage rate: If the hydrofluoric acid concentration C HF The wastewater flow rate V w Within the preset range R1, and the dosing rate Standard Deviation If the value is less than the standard deviation threshold -σ1, the system maintains the current dosage and dosage rate and remains in the normal state; If the hydrofluoric acid concentration C HF Exceeds the preset value P2, or the wastewater flow V w Exceeds the preset value P4, or the dosing rate The maximum value of If it exceeds the maximum threshold value M1, it switches to the alert state; In the general state, checks on parameter stability are included: If the fluoride concentration fluctuates ΔC F The mean is less than the set fluctuation threshold δ1, and the reaction tank level L tank Within the preset range R1, and the stirring speed R stir Within the stable range R2, the system continues to operate according to the current parameters and remains in a normal state; If the stirring speed R stir Variance Exceeds the set standard deviation threshold σ2, or the stirring speed R stir If the stable range R2 is exceeded and the reaction temperature T approaches the upper temperature limit T3 of the equipment, the system needs to reduce the stirring speed or extend the reaction time and switch to the alert state; In normal state, the prediction of effluent quality includes: If the effluent fluoride concentration predicted by historical data and current input parameters is Approaching the warning threshold T1, and the actual deviation ΔC F If it is within the normal range, the system will pre-adjust the dosage or reaction time to continue to maintain the normal state; If the predicted value of effluent fluoride concentration is Below the warning threshold T1, and the uniformity of the drug delivery H stir Keep stable, reduce the dosage of the system and maintain it in normal state.

4. The integrated equipment for preparing sodium fluorosilicate by resource utilization of photovoltaic wastewater according to claim 3, characterized in that: In the alert state, including dosing adjustments: If the current fluoride concentration C F Exceeds the warning threshold T1 but is lower than the upper threshold T2, and the dosage The coefficient of variation If it is within the normal range, the system needs to adjust the dosage to maintain the reaction effect and continue to remain in the alert state; If the fluoride concentration C F Exceeds the upper threshold T2, or the ambient temperature T env Or humidity H env Changes occur and the system enters the overload protection state; In the alert state, the environmental parameters are linked to control: If the pH value and temperature T deviate from the optimal operating range at the same time, and the ambient temperature T env Or humidity H env If there is a fluctuation, the system starts linkage control, adjusts the amount of acid and alkali added or the temperature control measures, and maintains it in an alert state; If the environmental parameter fluctuation exceeds the set threshold value P3 or P5 and causes the system to operate abnormally, the system switches to the overload protection state; In the alert state, including real-time monitoring and feedback: If the stirring speed R is monitored in real time stir Fluctuations occur, and the dosing rate If the control accuracy decreases, or the stirring speed exceeds the stable range R2, the system needs to dynamically adjust the stirring speed or dosing rate to continue to maintain the alert state; If the effluent fluoride concentration The real-time detection value is close to the upper threshold T2, and the reaction time T r It is close to the maximum allowable value. The system prolongs the reaction time or slows down the dosing rate to avoid the water quality not meeting the standard and switches to the overload protection state.

5. The integrated equipment for preparing sodium fluorosilicate by resource utilization of photovoltaic wastewater according to claim 4, characterized in that: In the overload protection state, load distribution and relief are included: If the current wastewater flow V w Exceeds the preset value P4, and the reaction tank liquid level L tank If the safety range R1 is exceeded, the system needs to automatically adjust the water inlet flow and divert part of the wastewater to the backup treatment unit, and the system remains in an overload protection state; If the device temperature T device and current consumption I device At the same time, the safety thresholds T3 and T4 are exceeded, and the device vibrates V vibration Display abnormality, that is, exceeding the vibration standard, the system needs to immediately reduce the load or suspend some operations and continue to maintain the overload protection state; In the overload protection state, it includes equipment protection and fault prevention: If the equipment running time T runtime Exceeding the preset time P runtime , and the equipment wear state W is detected wear Increase, the system starts the equipment maintenance program to prevent the equipment from continuing to run under high load, causing failure occur; If the device's self-test result is D diagnosis Indicates that there is a potential failure risk and the failure probability P fault Increase, the system arranges preventive maintenance or repair, and continues to maintain the overload protection state; In the overload protection state, it includes self-checking and repairing: If the device health status is H device Decreasing, and the self-check program detects an abnormality, the system needs to immediately trigger the self-check and repair program and continue to maintain the overload protection state; If the fluctuation range of the equipment's operating parameters is ΔP device If it exceeds the normal range and the operation history shows that similar fluctuations have caused faults, the system needs to issue early warnings and adjust parameters to prevent the fault from recurring and continue to maintain the overload protection state.

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