Coupling measurement device and method for solubility in crystallization process

Abstract

The invention discloses a coupling measurement device and method for solubility in the crystallization process, and relates to the field of solubility measurement in the crystallization process, and the device comprises an upper computer, a coupling measurement module, a stirrer and a crystallizer; the upper computer is connected with one end of the stirrer; the other end of the stirrer is arranged at the bottom of the crystallizer; the crystallizer is used for containing liquid and a to-be-detected substance; the coupling measurement module comprises an online infrared analyzer, a temperature detector and a sound rod variable amplitude ultrasonic reactor; the online infrared analyzer comprises a probe sensor, and the probe sensor is used for monitoring an infrared spectrogram of a to-be-detected substance; the temperature detector is used for measuring the temperature of liquid; the sound rod variable-amplitude ultrasonic reactor is used for strengthening the reaction process; and the upper computer is used for determining the solubility of the substance to be detected based on the infrared spectrogram and the temperature. According to the invention, the measurement precision of the substance solubility in the crystallization process is improved.

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 basic chemical process and an important unit operation of manufacturing, separation and purification in chemical production. In the industrial crystallization process, the production capacity of the crystallization process depends on its solid-liquid phase equilibrium relationship. The realization of the industrial crystallization process is mainly through the process design and optimization methods based on the thermodynamic data of the material to be crystallized, that is, the solubility, supersolubility and other properties. Therefore, in order to make the solute crystallize better and faster, it is necessary to master the solid-liquid equilibrium parameters of the solid solute and the solution, and solubility is the basis. The solubility curve is a curve of the solubility of a solid substance as a function of temperature, indicating the solid-liquid thermodynamic equilibrium state of the system. In addition, solubility is inseparable from supersaturation. Supersaturation is the driving force for nucleation and crystal growth during the crystallization process, and has a significant impact on the quality of the crystal product. The so-called supersaturation is the difference between the concentration of the solute in the system and the solubility of the system at that temperature. Therefore, solubility is an important basic data for understanding the solubility characteristics between the components of the crystal system and grasping its crystallization law.

[0003] There are many methods for measuring the solubility of existing substances, including gravimetric method, turbidity method, conductivity method and laser method. The gravimetric method is to weigh the saturated supernatant of the solution that has reached solid-liquid equilibrium, dry it until the solvent is completely volatilized, measure the mass of the solute after drying, calculate the mass of the volatilized solvent, and obtain the solution concentration. This method has a long measurement cycle, and the sampling process and external environment will affect its results.

[0004] The solubility of the substance to be tested can be measured based on turbidity, which can be divided into offline measurement and online measurement. Offline measurement is suitable for systems where turbidity does not change with time, temperature and other environmental conditions, while online measurement can be used for systems where turbidity changes with environmental conditions. For example, there is a method in the related art that measures the data of turbidity and temperature changes of the 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 substance to be tested, and determines the solubility of the substance to be tested. This method requires a long period of time to measure the turbidity data and temperature data of the suspension, and has low monitoring accuracy in complex systems.

[0005] The conductivity method is one of the more popular methods for determining solubility, which is based on the relationship between conductivity and the concentration of the substance to be measured. For example, there is a method in the related art that determines the solubility of the substance to be measured based on the mutation point in the conductivity-temperature relationship curve during the heating process. This method has strong practicality, but it is mainly suitable for measuring substances with strong conductivity. It is difficult to accurately measure the solubility of weak electrolyte and non-electrolyte solution systems.

[0006] The laser method determines the solubility of the substance to be tested 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 methods for measuring solubility in the crystallization process mainly estimate the solubility by analyzing and measuring the physical and chemical properties of the liquid phase, such as weight, turbidity, conductivity, and refractive index. In practical applications, there are still many problems such as low measurement accuracy, long cycle, and overly complex measurement. Therefore, it is necessary to develop a fast, simple, effective, and widely applicable process analysis tool to online monitor the changes in solution concentration during the crystallization process. Summary of the invention

[0008] The purpose of the present 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 and a crystallizer; 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;

[0012] The coupling measurement module is used to measure the infrared spectrum of the substance to be tested, the temperature of the liquid and the enhanced reaction process under ultrasound; the coupling measurement module includes 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 includes a probe sensor, and the probe sensor 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 variable amplitude ultrasonic reactor is used to enhance 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 acoustic rod variable amplitude ultrasonic reactor is arranged between the second baffle and the side wall of the crystallizer.

[0017] Optionally, the crystallizer is a double-jacketed container, comprising an inner container and an outer container, the inner container being arranged inside the outer container, and a cavity being 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, and the outer container is provided with a circulating water inlet and a circulating water outlet; the cavity is used to hold a fluid, and the fluid flows in from the circulating water inlet and flows out from the circulating water outlet to perform water bath heating on the crystallizer.

[0018] Optionally, 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.

[0019] Optionally, the temperature detector is arranged on the inner side of the shell.

[0020] 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;

[0021] The amplifier is used for amplifying the infrared spectrum and the temperature.

[0022] Optionally, the host computer is also used to display the infrared spectrum of the substance to be tested and the temperature.

[0023] In a second aspect, the present application further provides a coupled measurement method for solubility in a crystallization process, wherein the coupled measurement method for solubility in a crystallization process is applied to the coupled measurement device for solubility in a crystallization process, and the coupled measurement method for solubility in a crystallization process comprises:

[0024] Configure the installation locations of the agitator, online infrared analyzer and program temperature controller;

[0025] Weigh a certain amount of liquid and add it into the inner container;

[0026] 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;

[0027] Add the substance to be tested, weigh and record the mass of the substance to be tested each time;

[0028] 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;

[0029] The host computer records the infrared spectrum trend graph, and after each added test substance is completely dissolved, records the characteristic peak height corresponding to the infrared spectrum graph, and establishes a function model based on the characteristic peak height to two-point baseline height type to obtain the solubility of the test substance in the liquid at the set temperature.

[0030] According to the specific embodiments provided in this application, this application has the following technical effects:

[0031] The present application provides a coupled measurement device and method for solubility in a crystallization process, comprising: a host computer, a coupled measurement module, a stirrer and a crystallizer; 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 contain liquid and a substance to be tested; the coupled measurement module is used to measure the infrared spectrum of the substance to be tested, 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, and the probe sensor is used to monitor the infrared spectrum of the substance to be tested 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 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. 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 paying creative work.

[0033] Figure 1 A schematic diagram of the structure of a coupled measurement device for solubility in a crystallization process provided in one embodiment of the present application;

[0034] Figure 2 A schematic diagram of the structure of the probe sensor provided for this application;

[0035] Figure 3 A flow chart of the coupled measurement method for solubility in the crystallization process provided in this application;

[0036] Figure 4 293.15K, 100g CO3 in water 2- Ion online monitoring infrared spectrum.

[0037] Figure markings: 1-crystallizer, 2-controller, 3-motor, 4-online infrared analyzer socket, 5-sound rod amplitude ultrasonic reactor socket, 6-online infrared analyzer, 7-sound rod amplitude 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

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] In order to make the above-mentioned objects, 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.

[0040] 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.

[0041] This application aims at the industrial crystallization process, and has developed a fast and accurate coupling measurement device and method to realize 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 also can be used for the determination of the solubility of insoluble substances and mixed systems. This application can not only be used for online monitoring of the solubility of the crystallization process, but also can monitor the changes in intermediate products in 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 operation instruments, strong practicality, and can realize online measurement.

[0042] 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 and a crystallizer 1; 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.

[0043] The crystallizer 1 is used to hold liquid and test substances; a circulating water inlet 10, a circulating water outlet 11, a first feed inlet 13 and a second feed inlet 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.

[0044] The coupling measurement module is used to measure the infrared spectrum of the substance to be tested, the temperature of the liquid and the ultrasonic enhanced reaction process; the coupling measurement module includes an online infrared analyzer 6, a temperature detector 17 and a sonic rod variable amplitude ultrasonic reactor 7; the online infrared analyzer 6, the temperature detector 17 and the sonic rod variable amplitude ultrasonic reactor 7 are all connected to the host computer; the online infrared analyzer 6 includes a probe sensor 12, and the probe sensor 12 is used to monitor the infrared spectrum of the substance to be tested in real time; the temperature detector 12 is arranged on the inner side of the probe sensor 17, and the temperature detector 12 is used to measure the temperature of the liquid; the sonic rod variable amplitude 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 variable amplitude ultrasonic reactor 7 is inserted into the interior of the crystallizer 1 through the sonic rod variable amplitude ultrasonic reactor socket 5.

[0045] The host computer is used to determine the solubility of the substance to be tested based on the infrared spectrum and the temperature.

[0046] 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 the reaction process under ultrasound. 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 inlet 13, a second feed inlet 14 and a discharge port 15; the coupled measurement device includes an online infrared analyzer 6 and a sound 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, and the temperature detector 17 is arranged inside the probe sensor 12; the sound rod variable amplitude ultrasonic reactor 7 is configured to strengthen the reaction process.

[0047] As an optional embodiment, the stirrer 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; the stirring blade 8 is arranged on the stirring shaft 9. The stirring blade 8 is arranged below the liquid surface of the substance to be tested, and the stirring shaft 9 of the stirrer is configured to be arranged vertically to the liquid surface of the substance to be tested.

[0048] As an optional embodiment, 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 rotate synchronously with the stirring shaft. In practical applications, baffles 24 (first baffle and second baffle) are arranged on both sides of the stirrer, and the baffles 24 can rotate synchronously with the stirring shaft 9 around the stirring shaft 9 to enhance uniform mixing of the solution.

[0049] As an optional implementation, the online infrared analyzer is arranged between the first baffle and the side wall of the crystallizer, and the sound rod variable amplitude 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 sound rod variable amplitude ultrasonic reactor 7 with the inner wall of the crystallizer 1.

[0050] As an optional embodiment, the crystallizer 1 is a double-layer 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 the fluid, and the fluid flows in from the circulating water inlet 10 and flows out from the circulating water outlet 11, so that the temperature of the system such as the solution to be tested placed in the inner container can be accurately controlled to heat the crystallizer in a water bath.

[0051] 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 a columnar structure; the optical system 20, the detector 21 and the infrared beam 19 are all arranged inside the housing 18; the infrared beam 19 irradiates the detector 21 through the optical system 20. The optical system 20 is made of silicon material, and the temperature detector 17 is arranged on the inner wall of the housing 18 of the probe sensor.

[0052] 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 and the temperature.

[0053] The host computer is also used to display the infrared spectrum of the substance to be tested and the temperature.

[0054] In an exemplary embodiment, Figure 3 As shown, the present application also provides a coupled measurement method for solubility in a crystallization process, the coupled measurement method for solubility in a crystallization process is applied to the coupled measurement device for solubility in a crystallization process, and the coupled measurement method for solubility in a crystallization process includes:

[0055] The installation positions of the stirrer, the online infrared analyzer and the program temperature controller are configured, including setting the stirrer in a vertical state in the crystallizer and setting the online infrared analyzer between the baffle and the inner wall of the crystallizer.

[0056] Prepare the solution of the system to be tested, weigh a certain amount of liquid (solution) and add it into the inner container.

[0057] 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.

[0058] Add the substance to be tested, weigh and record the mass of the substance to be tested each time.

[0059] 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.

[0060] The host computer records the infrared spectrum trend graph, and after each added test substance is completely dissolved, records the characteristic peak height corresponding to the infrared spectrum graph, and establishes a function model based on the characteristic peak height to two-point baseline height type to obtain the solubility of the test substance in the liquid at the set temperature.

[0061] The coupled measurement device and method for solubility in a crystallization process provided in the present application can realize accurate and efficient measurement of the solubility of solid substances, which is explained below through three specific embodiments.

[0062] Example 1: 100 g of water is placed in an inner container, and the temperature is controlled by controlling a programmable temperature controller to fill the jacket with fluid, and the agitator is controlled to stir the solution.

[0063] 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.

[0064] 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 increases accordingly. As lithium carbonate dissolves, CO3 2- The characteristic peak intensity tends to balance, 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 peak height of the spectrum 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 changing with the amount of lithium carbonate added, Figure 4 (c) 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.

[0065] 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 It 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 a crystallization process solubility measurement device and method provided in the present application.

[0066] Using the same method, the solubility of lithium carbonate in water at 303.15K is 1.2324g / 100g, the solubility of lithium carbonate in water at 313.15K is 1.0933g / 100g, the solubility of lithium carbonate in water at 323.15K is 0.9985g / 100g, the solubility of lithium carbonate in water at 333.15K is 0.9369g / 100g, the solubility of lithium carbonate in water at 343.15K is 0.8170g / 100g, the solubility of lithium carbonate in water at 353.15K is 0.7549g / 100g, the solubility of lithium carbonate in water at 363.15K is 0.6770g / 100g, and the solubility of lithium carbonate in water at 368.15K is 0.6089g / 100g.

[0067] 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 the gravimetric method and compared with the literature. The results are shown in Table 1.

[0068] Table 1 Comparison of measurement results of different measurement methods

[0069]

[0070] As can be seen from Table 1, the solubility of lithium carbonate in water measured by gravimetric method and infrared analysis method is very close to the results measured in the literature. The main reason for the difference in results is that when the solubility of lithium carbonate is measured by gravimetric method, the solvent will evaporate as the temperature rises, causing experimental errors; in addition, the external environment such as the temperature of the pipette during sampling will also affect the measurement results. However, the solubility of lithium carbonate is monitored online in real time using an infrared probe, and the temperature control is more precise. There is no need to separate lithium carbonate for separate analysis, which minimizes the impact of the external environment on the measurement results, indicating that the solubility data measured by infrared analysis method is credible.

[0071] Embodiment 2: This embodiment is the same as the device of the above embodiment 1, and a 0.4374 mol / L sodium chloride solution is prepared, and 100 g is weighed and placed in an inner container, the temperature is controlled by controlling the program temperature controller to fill the jacket with fluid, and the sodium chloride 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 increases accordingly. As lithium carbonate dissolves, CO3 2- The characteristic peak intensity tends to balance, 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.

[0074] Embodiment 3: This embodiment is the same as the device of the above-mentioned embodiment 1, and 0.4374mol / L sodium chloride solution, 0.0013mol / L sodium sulfate solution and 0.06mol / L potassium chloride solution are respectively configured, and 100g of the mixed solution is weighed and placed in the inner container, and the temperature is controlled by controlling the program temperature controller to fill the jacket with fluid, and the sodium chloride solution is stirred by controlling the agitator.

[0075] 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.

[0076] 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 increases accordingly. As lithium carbonate dissolves, CO3 2- The characteristic peak intensity tends to balance, 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.

[0077] The present application can monitor the dissolution state of the substance to be tested in the solution in real time by immersing the probe sensor into the solution, which can reduce the interference of temperature and external environment on the solubility measurement of the substance to be tested, and has a wide measurement temperature range, can obtain the measurement results synchronously, and can also obtain the instantaneous concentration of the system to be tested, and has a simple structure. Because the probe sensor is sensitive to the concentration of the solution, it is not limited by temperature, and the measurement response time is short, synchronous measurement can be achieved. Compared with other solubility measurement methods, this online monitoring method is more convenient and more accurate.

[0078] The technical features of the above embodiments may be arbitrarily combined. 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.

[0079] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will 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: A host computer, a coupling measurement module, a stirrer and a crystallizer; 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 coupling measurement module is used to measure the infrared spectrum of the substance to be tested, the temperature of the liquid and the enhanced reaction process under ultrasound; the coupling measurement module includes 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 includes a probe sensor, and the probe sensor 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 variable amplitude ultrasonic reactor is used to enhance 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 plate and the second baffle plate 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 acoustic 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 crystallizer is a double-layer jacketed container, comprising an inner container and an outer container, wherein 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, and the outer container is provided with a circulating water inlet and a circulating water outlet; the cavity is used to hold a fluid, and the fluid flows in from the circulating water inlet and flows out from the circulating water outlet, so as to perform water bath heating on the crystallizer.

6. The coupled measurement device for solubility in a crystallization process according to claim 1, characterized in that: The probe sensor comprises 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.

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

8. 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 for amplifying the infrared spectrum and the temperature.

9. 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.

10. A coupled measurement method for solubility in a crystallization process, characterized in that: The coupled measurement method of the solubility in the crystallization process is applied to the coupled measurement device of the solubility in the crystallization process according to any one of claims 1 to 9, and the coupled measurement method of the solubility in the crystallization process 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; 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; 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, and after each added test substance is completely dissolved, records the characteristic peak height corresponding to the infrared spectrum graph, and establishes a function model based on the characteristic peak height to two-point baseline height type to obtain the solubility of the test substance in the liquid at the set temperature.

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