A coupled measurement device and method for solubility in a crystallization process

Abstract

This application discloses a coupled measurement device and method for solubility in a crystallization process, relating to the field of solubility measurement in crystallization processes. The device comprises a host computer, a coupled measurement module, an agitator, and a crystallizer; the host computer is connected to one end of the agitator; the other end of the agitator is placed at the bottom of the crystallizer; the crystallizer is used to hold liquid and a substance to be measured; the coupled measurement module comprises an online infrared analyzer, a temperature detector, and a sonic boom variable amplitude ultrasonic reactor; the online infrared analyzer comprises a probe sensor for monitoring the infrared spectrum of the substance to be measured; the temperature detector is used to measure the temperature of the liquid; the sonic boom variable amplitude ultrasonic reactor is used to intensify the reaction process; and the host computer is used to determine the solubility of the substance to be measured based on the infrared spectrum and temperature. This application improves the measurement accuracy of the solubility of substances in the crystallization process.

Description

Technical Field

[0001] The present application relates to the field of solubility measurement in a crystallization process, and in particular to a coupled measurement device and method for solubility in a crystallization process. Background Art

[0002] Crystallization is a fundamental chemical process and a crucial unit operation for manufacturing, separation, and purification in chemical production. In industrial crystallization, the process's production capacity depends on its solid-liquid equilibrium. Industrial crystallization processes are primarily implemented through process design and optimization based on thermodynamic data of the substance to be crystallized, specifically properties such as solubility and supersolubility. Therefore, to achieve optimal and rapid crystallization of the solute, it is essential to understand the solid-liquid equilibrium parameters between the solid solute and the solution, with solubility being the foundation. A solubility curve plots the solubility of a solid substance versus temperature, indicating the system's solid-liquid thermodynamic equilibrium state. Furthermore, solubility is closely linked to supersaturation, which drives nucleation and crystal growth during crystallization and significantly impacts the quality of the resulting crystal. Supersaturation is the difference between the solute concentration in a system and its solubility at that temperature. Therefore, solubility is a crucial fundamental data point for understanding the solubility characteristics of the components in a crystalline system and for understanding the underlying crystallization laws.

[0003] Existing methods for measuring the solubility of substances include gravimetric, turbidometric, conductivity, and laser methods. The gravimetric method involves weighing the saturated supernatant of a solution that has reached solid-liquid equilibrium, drying it until the solvent is completely evaporated, measuring the mass of the dried solute, and calculating the mass of the evaporated solvent to obtain the solution concentration. This method has a long measurement cycle, and the sampling process and external environment can affect the results.

[0004] Turbidity-based solubility measurements of test substances can be divided into offline and online measurements. Offline measurements are suitable for systems where turbidity does not change with time, temperature, or other environmental factors, while online measurements can be used for systems where turbidity changes with environmental conditions. For example, one method in the related art measures the turbidity and temperature of a suspension online over time, and uses the point where the mean or standard deviation of the turbidity data changes significantly over time as the solubility point of the test substance to determine the solubility of the test substance. However, this method requires a long cycle to measure the turbidity and temperature data of the suspension, and has low monitoring accuracy in complex systems.

[0005] Conductivity is a popular method for determining solubility, based on the relationship between conductivity and the concentration of the substance being measured. For example, one method in the related art determines the solubility of a substance based on the breakpoint in the conductivity-temperature curve during a heating process. While this method is highly practical, it is primarily suitable for measuring highly conductive substances and has difficulty accurately measuring the solubility of weak electrolyte and non-electrolyte solutions.

[0006] The laser method determines the solubility of the substance to be measured based on the light intensity mutation point. It can realize online measurement, but it is easily affected by small crystal particles or impurities.

[0007] The above-mentioned methods for measuring solubility during crystallization primarily rely on analyzing and measuring the liquid phase's physicochemical properties, such as weight, turbidity, conductivity, and refractive index, to estimate solubility. However, in practical applications, these methods suffer from numerous issues, including low measurement accuracy, long cycle times, and excessive measurement complexity. Therefore, a fast, simple, effective, and widely applicable process analysis tool is needed to online monitor changes in solution concentration during crystallization. Summary of the Invention

[0008] The purpose of this application is to provide a coupled measurement device and method for solubility in a crystallization process, so as to improve the measurement accuracy of the solubility of a substance in the crystallization process.

[0009] To achieve the above objectives, this application provides the following solutions:

[0010] In a first aspect, the present application provides a coupled measurement device for solubility in a crystallization process, comprising: a host computer, a coupled measurement module, a stirrer, a crystallizer, and a programmable temperature controller; the host computer is connected to one end of the stirrer; the other end of the stirrer is placed at the bottom of the crystallizer;

[0011] The crystallizer is used to hold liquid and a substance to be tested; a circulating water inlet, a circulating water outlet, a first feed inlet and a second feed inlet are provided on the side wall of the crystallizer; the height of the circulating water outlet is higher than the height of the circulating water inlet; a discharge port is provided at the bottom of the crystallizer; the crystallizer is a double-jacketed container, the crystallizer comprises an inner container and an outer container, the inner container is arranged inside the outer container, and a cavity is formed between the outer wall of the inner container and the inner wall of the outer container; the inner container is used to hold the liquid and the substance to be tested, the outer container is provided with a circulating water inlet and a circulating water outlet; the cavity is used to hold a fluid, the fluid flows in from the circulating water inlet and flows out from the circulating water outlet to heat the liquid in a water bath; the program temperature controller heats the liquid in a water bath by filling the crystallizer cavity with circulating water;

[0012] The coupled measurement module is used to measure the infrared spectrum of the substance to be tested, the temperature of the liquid, and to strengthen the reaction process; the coupled measurement module includes an online infrared analyzer, a temperature detector, and a sonic rod amplitude-variable ultrasonic reactor; the online infrared analyzer, the temperature detector, and the sonic rod amplitude-variable ultrasonic reactor are all connected to the host computer; the online infrared analyzer includes a probe sensor, which is used to monitor the infrared spectrum of the substance to be tested in real time; the temperature detector is arranged on the inner side of the probe sensor, and the temperature detector is used to measure the temperature of the liquid; the sonic rod amplitude-variable ultrasonic reactor is used to strengthen the reaction process;

[0013] The host computer is used to determine the solubility of the substance to be tested based on the infrared spectrum and the temperature.

[0014] Optionally, the agitator includes a controller, a motor, a stirring shaft and a stirring blade; the controller is connected to the host computer and the motor respectively; the motor is connected to one end of the stirring shaft; the other end of the stirring shaft is placed at the bottom of the crystallizer; the stirring shaft is coaxially arranged with the crystallizer; and the stirring blade is arranged on the stirring shaft.

[0015] Optionally, it further includes: a first baffle and a second baffle; the first baffle and the second baffle are respectively arranged on both sides of the stirring shaft; the first baffle and the second baffle both rotate synchronously with the stirring shaft.

[0016] Optionally, the online infrared analyzer is arranged between the first baffle and the side wall of the crystallizer; the sonic rod variable amplitude ultrasonic reactor is arranged between the second baffle and the side wall of the crystallizer.

[0017] Optionally, the probe sensor includes a housing, an optical system, a detector and an infrared beam; the housing is a columnar structure; the optical system, the detector and the infrared beam are all arranged inside the housing; the infrared beam is irradiated onto the detector through the optical system.

[0018] Optionally, the temperature detector is arranged on the inner side of the shell.

[0019] Optionally, an amplifier is further included; one end of the amplifier is connected to the probe sensor and the temperature detector respectively; the other end of the amplifier is connected to the host computer;

[0020] The amplifier is used to amplify the infrared spectrum signal and the temperature signal.

[0021] Optionally, the host computer is further configured to display the infrared spectrum of the substance to be tested and the temperature.

[0022] In a second aspect, the present application further provides a coupled measurement method for solubility during a crystallization process. The coupled measurement method for solubility during a crystallization process is applied to the coupled measurement device for solubility during a crystallization process. The coupled measurement method for solubility during a crystallization process includes:

[0023] Configure the installation locations of the agitator, online infrared analyzer and program temperature controller;

[0024] Weigh a certain amount of liquid and add it into the inner container;

[0025] controlling the stirrer to stir the liquid, and the programmable temperature controller to heat the liquid in a water bath by filling the crystallizer cavity with circulating water;

[0026] Add the substance to be tested, weigh and record the mass of the substance to be tested each time;

[0027] Measuring the infrared spectrum of the substance to be tested in the liquid by a probe sensor, and measuring the temperature of the liquid by a temperature detector;

[0028] The host computer records the infrared spectrum trend graph. After the added test substance is completely dissolved each time, the peak height of the characteristic peak corresponding to the infrared spectrum graph is recorded. A function model is established based on the height from the characteristic peak height to the two-point baseline to obtain the solubility of the test substance at the set temperature.

[0029] According to the specific embodiments provided in this application, this application has the following technical effects:

[0030] The present application provides a coupled measurement device and method for solubility in a crystallization process, comprising: a host computer, a coupled measurement module, an agitator, and a crystallizer; the host computer is connected to one end of the agitator; the other end of the agitator is placed at the bottom of the crystallizer; the crystallizer is used to hold a liquid and a substance to be measured; the coupled measurement module is used to measure the infrared spectrum of the substance to be measured, the temperature of the liquid, and monitor the reaction state of the system under ultrasound; the coupled measurement module comprises an online infrared analyzer, a temperature detector, and a sonic rod variable amplitude ultrasonic reactor; the online infrared analyzer, the temperature detector, and the sonic rod variable amplitude ultrasonic reactor are all connected to the host computer; the online infrared analyzer comprises a probe sensor, the probe sensor is used to monitor the infrared spectrum of the substance to be measured in real time; the temperature detector is used to measure the temperature of the liquid; the sonic rod variable amplitude ultrasonic reactor is used to intensify the reaction process; and the host computer is used to determine the solubility of the substance to be measured based on the infrared spectrum and the temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A schematic structural diagram of a coupled measurement device for solubility in a crystallization process provided in one embodiment of the present application;

[0033] Figure 2 A schematic diagram of the structure of the probe sensor provided in this application;

[0034] Figure 3 A flow chart of the coupled measurement method for solubility in the crystallization process provided in this application;

[0035] Figure 4 293.15K, 100g CO3 in water 2- Infrared spectrum of ion online monitoring.

[0036] Figure markings: 1-crystallizer, 2-controller, 3-motor, 4-online infrared analyzer socket, 5-sound rod amplitude variable ultrasonic reactor socket, 6-online infrared analyzer, 7-sound rod amplitude variable ultrasonic reactor, 8-stirring blade, 9-stirring shaft, 10-circulating water inlet, 11-circulating water outlet, 12-probe sensor, 13-first feed inlet, 14-second feed inlet, 15-discharge port, 16-display, 17-temperature detector, 18-probe housing, 19-infrared beam, 20-optical system, 21-detector, 22-inner container, 23-outer container, 24-baffle. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0039] In recent years, infrared spectroscopy has been mainly used to analyze all physical properties of samples such as gases, liquids and solids, and can monitor changes in solution concentration during reaction crystallization in real time.

[0040] This application is aimed at industrial crystallization processes and has developed a fast and accurate coupling measurement device and method to achieve online monitoring of the solubility of the substance to be measured. This device and method can not only accurately and quickly measure the solubility of the substance to be measured, but can also be used to determine the solubility of insoluble substances and solutes in mixed systems. This application can not only be used for online monitoring of the solubility of the crystallization process, but also monitor the changes in intermediate products during the chemical reaction process and the reaction state of the system under ultrasound. There is no need to separate the substances and analyze them separately, and it can minimize the impact of the external environment on the measurement results, improve the measurement accuracy and efficiency of the solubility, and has a wide measurement temperature range, simple operating instruments, strong practicality, and can achieve online measurement.

[0041] In an exemplary embodiment, Figure 1 As shown, a coupled measurement device for solubility in a crystallization process is provided, comprising: a host computer (i.e., a display 16), a coupled measurement module, a stirrer, a crystallizer 1, and a programmable temperature controller; the host computer is connected to one end of the stirrer; and the other end of the stirrer is placed at the bottom of the crystallizer 1.

[0042] The crystallizer 1 is used to hold liquid and test substances; a circulating water inlet 10, a circulating water outlet 11, a first feed port 13 and a second feed port 14 are provided on the side wall of the crystallizer 1; the height of the circulating water outlet 11 is higher than the height of the circulating water inlet 10; a discharge port 15 is provided at the bottom of the crystallizer 1.

[0043] The coupled measurement module is used to measure the infrared spectrum of the substance to be tested, the temperature of the liquid, and the ultrasonic enhancement reaction process; the coupled measurement module includes an online infrared analyzer 6, a temperature detector 17, and a sonic rod amplitude-variable ultrasonic reactor 7; the online infrared analyzer 6, the temperature detector 17, and the sonic rod amplitude-variable ultrasonic reactor 7 are all connected to the host computer; the online infrared analyzer 6 includes a probe sensor 12, which is used to monitor the infrared spectrum of the substance to be tested in real time; the temperature detector 17 is arranged on the inner side of the probe sensor 12, and the temperature detector 17 is used to measure the temperature of the liquid; the sonic rod amplitude-variable ultrasonic reactor 7 is used to enhance the reaction process. In actual application, the online infrared analyzer 6 is inserted into the interior of the crystallizer 1 through the online infrared analyzer socket 4; the sonic rod amplitude-variable ultrasonic reactor 7 is inserted into the interior of the crystallizer 1 through the sonic rod amplitude-variable ultrasonic reactor socket 5.

[0044] The host computer is used to determine the solubility of the substance to be tested based on the infrared spectrum and the temperature.

[0045] In practical applications, the coupled measurement device for the solubility of the crystallization process in the present application includes an agitator, a crystallizer 1 for placing the substance to be tested, and a coupled measurement module configured to simultaneously measure the solubility of the substance to be tested and strengthen the reaction process. The agitator includes a stirring shaft 9 coaxial with the crystallizer 1 and a stirring blade 8 arranged on the stirring shaft 9, and the crystallizer 1 is provided with a circulating water inlet 10 and a circulating water outlet 11 and a first feed port 13, a second feed port 14 and a discharge port 15; the coupled measurement device includes an online infrared analyzer 6 and a sonic rod variable amplitude ultrasonic reactor 7, the online infrared analyzer 6 includes a probe sensor 12, the probe sensor 12 is configured to monitor the solubility of the substance to be tested in real time, and also includes a temperature detector 17 configured to simultaneously measure the temperature of the substance to be tested, the temperature detector 17 is arranged inside the probe sensor 12; the sonic rod variable amplitude ultrasonic reactor 7 is configured to strengthen the reaction process.

[0046] As an optional embodiment, the agitator includes a controller 2, a motor 3, a stirring shaft 9, and a stirring blade 8; the controller 2 is connected to the host computer and the motor 3 respectively; the controller 2 is configured to control the rotation of the motor 3, the rotating shaft of the motor 3 is connected to one end of the stirring shaft 9, and is configured to drive the stirring shaft 9 to rotate, thereby driving the stirring blade 8 to rotate; the other end of the stirring shaft 9 is placed at the bottom of the crystallizer 1; the stirring shaft 9 is coaxially arranged with the crystallizer 1; and the stirring blade 8 is arranged on the stirring shaft 9. The stirring blade 8 is arranged below the liquid level of the substance to be tested, and the stirring shaft 9 of the agitator is configured to be arranged perpendicular to the liquid level of the substance to be tested.

[0047] As an optional embodiment, the stirrer further includes: a first baffle and a second baffle; the first baffle and the second baffle are respectively disposed on either side of the stirring shaft; and both the first baffle and the second baffle rotate synchronously with the stirring shaft. In actual application, baffles 24 (first baffle and second baffle) are provided on both sides of the stirrer. Baffles 24 can rotate synchronously with the stirring shaft 9 around the stirring shaft 9 to enhance uniform mixing of the solution.

[0048] As an optional embodiment, the online infrared analyzer is arranged between the first baffle and the side wall of the crystallizer, and the acoustic rod amplitude variable ultrasonic reactor is arranged between the second baffle and the side wall of the crystallizer, which can avoid the collision of the online infrared analyzer 6 and the acoustic rod amplitude variable ultrasonic reactor 7 with the inner wall of the crystallizer 1.

[0049] As an optional embodiment, the crystallizer 1 is a double-jacketed container made of glass. The crystallizer 1 includes an inner container 22 and an outer container 23. The inner container 22 is arranged inside the outer container 23, and a cavity is formed between the outer wall of the inner container 22 and the inner wall of the outer container 23; the inner container 22 is used to hold the liquid and the substance to be tested, and the outer container 23 is provided with a circulating water inlet 10 and a circulating water outlet 11; the cavity is used to hold fluid, and the fluid flows into the circulating water inlet 10 and flows out of the circulating water outlet 11, which can accurately control the temperature of the system such as the solution to be tested placed in the inner container to heat the liquid in a water bath.

[0050] As an optional implementation, Figure 2 As shown, the probe sensor 12 includes a housing 18, an optical system 20, a detector 21, and an infrared beam 19. The housing 18 is cylindrical; the optical system 20, the detector 21, and the infrared beam 19 are all disposed within the housing 18; the infrared beam 19 is irradiated onto the detector 21 through the optical system 20. The optical system 20 is made of silicon, and the temperature detector 17 is disposed on the inner wall of the housing 18 of the probe sensor.

[0051] As an optional implementation, it also includes an amplifier; one end of the amplifier is connected to the probe sensor and the temperature detector respectively; the other end of the amplifier is connected to the host computer; the amplifier is used to sample and amplify the infrared spectrum signal and the temperature signal.

[0052] The host computer is also used to display the infrared spectrum of the substance to be tested and the temperature.

[0053] In an exemplary embodiment, Figure 3 As shown, the present application also provides a coupled measurement method for solubility during a crystallization process. The coupled measurement method for solubility during a crystallization process is applied to the coupled measurement device for solubility during a crystallization process. The coupled measurement method for solubility during a crystallization process includes:

[0054] The installation positions of the stirrer, online infrared analyzer, and programmable temperature controller are configured, including setting the stirrer in a vertical position in the crystallizer and setting the online infrared analyzer between the baffle and the inner wall of the crystallizer.

[0055] Prepare the solution of the system to be measured, weigh a certain amount of liquid (solution) and add it into the inner container.

[0056] The stirrer is controlled to stir the liquid, and the programmable temperature controller heats the liquid in a water bath by filling the crystallizer cavity with circulating water.

[0057] Add the substance to be tested, weigh and record the mass of the substance to be tested each time.

[0058] The infrared spectrum of the substance to be tested in the liquid is measured by the probe sensor, and the temperature of the liquid is measured by the temperature detector.

[0059] The host computer records the infrared spectrum trend graph. After the added test substance is completely dissolved each time, the peak height of the characteristic peak corresponding to the infrared spectrum graph is recorded. A function model is established based on the height from the characteristic peak height to the two-point baseline to obtain the solubility of the test substance at the set temperature.

[0060] The coupled measurement device and method for solubility in a crystallization process provided in this application can achieve accurate and efficient measurement of the solubility of solid substances, which is described below through three specific embodiments.

[0061] Example 1: 100 g of water was placed in an inner container, and the temperature was controlled by controlling a programmable temperature controller to fill the jacket with fluid, and the stirrer was controlled to stir the solution.

[0062] When the temperature reaches the set temperature, the background spectrum of the probe sensor 12 in the air is established, and then the probe sensor 12 is immersed in the solution.

[0063] Accurately weigh and record a certain amount of lithium carbonate and add it to the inner container. Before the lithium carbonate solution reaches saturation, each time a certain amount of solid lithium carbonate is added, CO3 2- The characteristic peak height of CO3 increases with the dissolution of lithium carbonate. 2- The characteristic peak intensity tends to be balanced, and lithium carbonate and CO3 are added continuously. 2- The peak intensity of the characteristic peak no longer increases, indicating that lithium carbonate has reached saturation in water, and the solubility is 1.3159g / 100g. Figure 4 As shown in (a), (b), and (c). Figure 4 (a) is the mass of lithium carbonate and CO3 2- The spectrum of the peak height changes with the amount of lithium carbonate added, Figure 4 (b) is the mass of lithium carbonate and CO3 2- The three-dimensional spectrum of the peak height changes with the amount of lithium carbonate added, Figure 4 (c) in the equation is CO3 2- The trend graph of the peak height changing with time, Figure 4 (d) in the equation is CO3 2- Function model diagram of the relationship between peak height and concentration.

[0064] According to the amount of lithium carbonate added each time and CO3 2- Characteristic peak height establishment Figure 4The function model diagram shown in (d) in the figure is used to obtain the amount of lithium carbonate added and CO3 2- The characteristic peak is proportional to the peak height, which conforms to the Lambert-Beer law. The function model has a good fit and the correlation coefficient R 2 The value is 0.9943, indicating that the correlation of the established model is very good, indicating that the solubility of lithium carbonate can be accurately and quickly determined using the device and method for measuring the solubility of the crystallization process provided by the present application.

[0065] Using the same method, the solubility of lithium carbonate in water at 303.15 K was 1.2324 g / 100 g, the solubility of lithium carbonate in water at 313.15 K was 1.0933 g / 100 g, the solubility of lithium carbonate in water at 323.15 K was 0.9985 g / 100 g, the solubility of lithium carbonate in water at 333.15 K was 0.9369 g / 100 g, the solubility of lithium carbonate in water at 343.15 K was 0.8170 g / 100 g, the solubility of lithium carbonate in water at 353.15 K was 0.7549 g / 100 g, the solubility of lithium carbonate in water at 363.15 K was 0.6770 g / 100 g, and the solubility of lithium carbonate in water at 368.15 K was 0.6089 g / 100 g.

[0066] In order to verify the reliability of the solubility measurement method provided in this application for the measured lithium carbonate solubility data, the measurement results were verified by gravimetric method and compared with the literature. The results are shown in Table 1.

[0067] Table 1 shows that the solubility of lithium carbonate in water measured by gravimetric and infrared analysis methods closely matches the results reported in the literature. The main reason for the discrepancy is that when measuring lithium carbonate solubility by gravimetric analysis, the solvent evaporates with increasing temperature, resulting in experimental error. Furthermore, the external environment during sampling, such as the temperature of the pipette, can also affect the results. However, real-time online monitoring of lithium carbonate solubility using an infrared probe allows for more precise temperature control, eliminating the need for separate analysis of the lithium carbonate, and minimizing the impact of the external environment on the results. This demonstrates the reliability of the solubility data obtained by infrared analysis.

[0068] Example 2: This embodiment has the same apparatus as that of Example 1 above, wherein a 0.4374 mol / L sodium chloride solution is prepared and 100 g of the solution is weighed and placed in an inner container. The temperature is controlled by filling the jacket with fluid using a programmable temperature controller, and the sodium chloride solution is stirred by controlling a stirrer.

[0069] When the temperature reaches the set temperature, the background spectrum of the probe sensor in the air is established, and then the probe sensor is immersed in the solution.

[0070] Accurately weigh and record a certain amount of lithium carbonate and add it to the inner container. Before the lithium carbonate solution reaches saturation, each time a certain amount of solid lithium carbonate is added, CO3 2- The characteristic peak height of CO3 increases with the dissolution of lithium carbonate. 2- The characteristic peak intensity tends to be balanced, and lithium carbonate and CO3 are added continuously. 2- The peak intensity of the characteristic peak no longer increases, indicating that lithium carbonate has reached saturation in the sodium chloride solution. The amount of lithium carbonate added before reaching saturation is calculated as its solubility at this temperature.

[0071] Example 3: This embodiment is the same as the apparatus of Example 1 above, and 0.4374 mol / L sodium chloride solution, 0.0013 mol / L sodium sulfate solution and 0.06 mol / L potassium chloride solution are respectively configured, and 100 g of the mixed solution is weighed and placed in the inner container. The temperature is controlled by controlling the program temperature controller so that the jacket is filled with fluid, and the mixed solution is stirred by controlling the agitator.

[0072] When the temperature reaches the set temperature, the background spectrum of the probe sensor in the air is established, and then the probe sensor is immersed in the solution.

[0073] Accurately weigh and record a certain amount of lithium carbonate and add it to the inner container. Before the lithium carbonate solution reaches saturation, each time a certain amount of solid lithium carbonate is added, CO3 2- The characteristic peak height of CO3 increases with the dissolution of lithium carbonate. 2- The characteristic peak intensity tends to be balanced, and lithium carbonate and CO3 are added continuously. 2- The characteristic peak intensity no longer increases, indicating that lithium carbonate has reached saturation in the mixed solution. The amount of lithium carbonate added before reaching saturation is calculated as its solubility at this temperature.

[0074] This application monitors the dissolution state of a substance to be measured in real time by immersing a probe sensor in a solution, reducing interference from temperature and the external environment on the solubility measurement of the substance to be measured. Furthermore, the measurement temperature range is wide, allowing for simultaneous measurement results and the instantaneous concentration of the system to be measured. The structure is simple. Because the probe sensor is sensitive to solution concentration and is not limited by temperature, and has a short measurement response time, synchronous measurement is possible. Compared to other solubility measurement methods, this online monitoring method is more convenient and accurate.

[0075] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A coupled measurement device for solubility in a crystallization process, characterized in that: include: Host computer, coupled measurement module, stirrer, crystallizer and program temperature controller; The host computer is connected to one end of the stirrer; the other end of the stirrer is placed at the bottom of the crystallizer; The crystallizer is used to hold liquid and a substance to be tested; a circulating water inlet, a circulating water outlet, a first feed inlet and a second feed inlet are provided on the side wall of the crystallizer; the height of the circulating water outlet is higher than the height of the circulating water inlet; a discharge port is provided at the bottom of the crystallizer; the crystallizer is a double-jacketed container, the crystallizer comprises an inner container and an outer container, the inner container is arranged inside the outer container, and a cavity is formed between the outer wall of the inner container and the inner wall of the outer container; the inner container is used to hold the liquid and the substance to be tested, the outer container is provided with a circulating water inlet and a circulating water outlet; the cavity is used to hold a fluid, the fluid flows in from the circulating water inlet and flows out from the circulating water outlet to heat the liquid in a water bath; the program temperature controller heats the liquid in a water bath by filling the crystallizer cavity with circulating water; The coupled measurement module is used to measure the infrared spectrum of the substance to be tested, the temperature of the liquid, and to strengthen the reaction process; the coupled measurement module includes an online infrared analyzer, a temperature detector, and a sonic rod amplitude-variable ultrasonic reactor; the online infrared analyzer, the temperature detector, and the sonic rod amplitude-variable ultrasonic reactor are all connected to the host computer; the online infrared analyzer includes a probe sensor, which is used to monitor the infrared spectrum of the substance to be tested in real time; the temperature detector is arranged on the inner side of the probe sensor, and the temperature detector is used to measure the temperature of the liquid; the sonic rod amplitude-variable ultrasonic reactor is used to strengthen the reaction process; The host computer is used to determine the solubility of the substance to be tested based on the infrared spectrum and the temperature.

2. The coupled measurement device for solubility in a crystallization process according to claim 1, characterized in that: The agitator includes a controller, a motor, a stirring shaft and a stirring blade; the controller is connected to the host computer and the motor respectively; the motor is connected to one end of the stirring shaft; the other end of the stirring shaft is placed at the bottom of the crystallizer; the stirring shaft is coaxially arranged with the crystallizer; and the stirring blade is arranged on the stirring shaft.

3. The coupled measurement device for solubility in a crystallization process according to claim 2, characterized in that: Also includes: A first baffle and a second baffle; the first baffle and the second baffle are respectively arranged on both sides of the stirring shaft; The first baffle and the second baffle both rotate synchronously with the stirring shaft.

4. The coupled measurement device for solubility in a crystallization process according to claim 3, characterized in that: The online infrared analyzer is arranged between the first baffle and the side wall of the crystallizer; the sonic rod variable amplitude ultrasonic reactor is arranged between the second baffle and the side wall of the crystallizer.

5. The coupled measurement device for solubility in a crystallization process according to claim 1, characterized in that: The probe sensor includes a shell, an optical system, a detector and an infrared beam; the shell is a columnar structure; the optical system, the detector and the infrared beam are all arranged inside the shell; the infrared beam is irradiated onto the detector through the optical system.

6. The coupled measurement device for solubility in a crystallization process according to claim 5, characterized in that: The temperature detector is arranged on the inner side of the shell.

7. The coupled measurement device for solubility in a crystallization process according to claim 1, characterized in that: It also includes an amplifier; one end of the amplifier is connected to the probe sensor and the temperature detector respectively; the other end of the amplifier is connected to the host computer; The amplifier is used to amplify the infrared spectrum signal and the temperature signal.

8. The coupled measurement device for solubility in a crystallization process according to claim 1, characterized in that: The host computer is also used to display the infrared spectrum of the substance to be tested and the temperature.

9. A coupled measurement method for solubility in a crystallization process, characterized in that: The coupled measurement method for solubility during crystallization is applied to the coupled measurement device for solubility during crystallization according to any one of claims 1 to 8, and the coupled measurement method for solubility during crystallization comprises: Configure the installation locations of the agitator, online infrared analyzer and program temperature controller; Weigh a certain amount of liquid and add it into the inner container; controlling the stirrer to stir the liquid, and the programmable temperature controller to heat the liquid in a water bath by filling the crystallizer cavity with circulating water; Add the substance to be tested, weigh and record the mass of the substance to be tested each time; Measuring the infrared spectrum of the substance to be tested in the liquid by a probe sensor, and measuring the temperature of the liquid by a temperature detector; The host computer records the infrared spectrum trend graph. After the added test substance is completely dissolved each time, the peak height of the characteristic peak corresponding to the infrared spectrum graph is recorded. A function model is established based on the height from the characteristic peak height to the two-point baseline to obtain the solubility of the test substance at the set temperature.

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