Inorganic salt solid particle spheroidizing device and using method thereof

Abstract

The invention provides an inorganic salt solid particle spheroidizing device. The inorganic salt solid particle spheroidizing device comprises a signal generation system, a vibration system, a stirring system and a dissolving system which are connected in sequence, the signal generation system is used for providing a vibration signal; the vibration system comprises a vibration exciter, a lower liquid storage tank, an upper liquid storage tank and a particle vibration plate arranged between the lower liquid storage tank and the upper liquid storage tank; the stirring system is arranged in the upper liquid storage tank; the dissolving system comprises a solvent inlet formed in the side face of the upper liquid storage tank and a solvent outlet formed in the bottom face of the lower liquid storage tank. The device is simple in structure, firm and durable, convenient to observe particle change and excellent in practicability; according to the invention, environmental protection can be realized, resources can be saved, and pollution-free continuous preparation of the spherical inorganic salt particles can be realized; the operation safety is high, the flexibility is high, and potential risks caused by liquid accumulation can be avoided through timely removal of the saturated solution.

Description

Technical Field

[0001] This invention belongs to the fields of materials science and chemical engineering, and specifically relates to a device for spheroidizing inorganic salt solid particles and its usage method. Background Technology

[0002] The study of spheroidization of inorganic salt particles is an important topic in materials science and chemical engineering. Compared with other materials, spherical or near-spherical inorganic salt particles have advantages such as high strength, high hardness, good particle flowability, high bulk density, and low coefficient of thermal expansion. These advantages play a crucial role in improving product performance. Spheroidized inorganic salt particles have a wide range of applications. Currently, the most common spherical particles on the market and their applications include: improving propellant performance requires the preparation of spherical ammonium perchlorate (AP) particles; near-spherical zinc oxide can be used in ceramic materials, varistors, cosmetics, antibacterial materials, photocatalytic materials, etc.; spherical silica is used in electronic packaging, biomedicine, mechanical polishing, and fluid transportation; spherical tungsten powder is used in the preparation of porous materials, sheet metal industry, thermal spraying, electronic information, military industry, automotive, powder metallurgy, etc.

[0003] With the rapid development of the global economy, my country's particle industry is booming, especially the technology and equipment for spheroidizing and shaping inorganic salt particles. Spherical particles, due to their high tap density and good flowability, are gradually becoming irreplaceable new materials. The preparation of high-quality inorganic salt spherical particles has always been a key focus and challenge in the industry. Particularly in the preparation of perchlorates, spheroidization can improve their thermal decomposition performance, hygroscopic properties, and dispersion performance of nano-combustion catalysts.

[0004] Currently, there are various methods for preparing spherical inorganic salt particles. Based on different preparation principles, they are mainly divided into three categories: physical methods, chemical methods, and high-temperature melting methods. Physical methods mainly include mechanical grinding and plasma methods, while chemical methods mainly include chemical precipitation, sol-gel methods, spray drying, and microwave synthesis. However, these methods for preparing spherical particles also have a series of drawbacks. For example, chemical precipitation may produce spherical particles with relatively low purity and large particle radii, making it unsuitable for fine particles, and may result in poor sintering between particles, affecting the performance of the final product. Mechanical grinding has disadvantages such as low purity, uneven particle size distribution, and high energy consumption, which may be even higher for some hard raw materials.

[0005] When a solvent is added to a saturated solution, the saturated solution becomes an unsaturated solution. To reach saturation, the solid particles will dissolve again. By incorporating a vibration and stirring system, the edges and corners of the inorganic salt solid particles can be controlled to dissolve first, thereby improving the sphericity of the particles. The factors influencing the preferential dissolution of the edges and corners of solid particles include four aspects: geometric structure and atomic arrangement, kinetic factors, and the symmetry of crystal growth and dissolution. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a device and method for spheroidizing inorganic salt solid particles, thereby overcoming a series of shortcomings in existing methods for producing spherical inorganic salt particles, such as: potentially low sphericity of the particles, relatively complex processes, potentially long preparation cycles, unfavorable for large-scale production, high heat consumption leading to low thermal efficiency, and high power consumption.

[0007] The specific plan is as follows: An inorganic salt solid particle spheroidization device includes a signal generation system, a vibration system, a stirring system, and a dissolving system connected in sequence. The signal generation system is used to provide vibration signals; The vibration system includes a vibrator, a lower liquid storage tank, an upper liquid storage tank, and a particle vibration plate disposed between the lower and upper liquid storage tanks; the vibrator receives vibration signals from the signal generation system and drives the entire vibration system to vibrate; the particle vibration plate is provided with micropores that allow solution flow but block solid particles. The stirring system is installed in the upper liquid storage tank to promote fluid flow in the upper liquid storage tank and promote preferential dissolution in areas with larger specific surface areas; The dissolving system includes a solvent inlet located on the side of the upper storage tank and a solvent outlet located on the bottom of the lower storage tank, for adding solvent to the stirring system and discharging solution.

[0008] Furthermore, the signal generation system includes a signal generator, a power amplifier, and an oscilloscope; the signal generator generates a vibration signal, which is amplified by the power amplifier to drive the exciter; the oscilloscope is used to detect the vibration waveform.

[0009] Furthermore, the vibration system also includes a connecting plate and a support device; the vibrator is located at the center of the support device; the connecting plate is fixed to the lower liquid storage tank and connected to the vibration position of the vibrator; the particle vibration plate is installed on the top of the lower liquid storage tank; and the upper liquid storage tank is placed on the particle vibration plate.

[0010] Furthermore, the stirring system includes a stirring shaft and a stirring blade installed therewith; the stirring shaft corresponds to the position of the vibrator; the stirring blade is one of a double-bladed integrated blade or a turbine blade.

[0011] Furthermore, the solvent inlet is connected to an injection pump via an inlet pipe; the distance between the inlet pipe and the central axis of the upper storage tank is 5 cm; and a valve is also installed at the solvent outlet.

[0012] Furthermore, it also includes an image analysis system; the image analysis system includes an industrial camera for capturing images of solid particles, a panel light source for providing illumination, and a data processing unit for analyzing the images to obtain particle sphericity.

[0013] Furthermore, the method of using this device is as follows: S1. Prepare a saturated solution and place it together with the inorganic salt solid particles to be spherized in the upper storage tank, and close the valve at the bottom of the lower storage tank so that the saturated solution completely submerges the inorganic salt solid particles. S2. Connect the injection pump to the inlet pipe, turn on the oscilloscope, signal generator and power amplifier in sequence, set the required vibration frequency and amplitude parameters, and drive the vibration system to start working, so that the inorganic salt solid particles generate regular vibration and mutual friction on the particle vibration plate. At the same time, turn on the stirring paddle switch, start the stirring system, set the stirring speed, so that the saturated solution in the upper storage tank will flow, disturb the inorganic salt solid particles and promote fluid mixing; S3. Solvent is added to the saturated solution system in the upper storage tank through an injection pump to turn the saturated solution into an unsaturated solution. This causes the edges and corners of the inorganic salt solid particles to dissolve first, thereby increasing the sphericity of the particles. The unsaturated solution then becomes a saturated solution again. At the same time, the enriched solution produced during the dissolution process flows into the lower storage tank through the particle vibration plate. S4. After stirring for 3-4 minutes, stop feeding and stirring. Use an image analysis system to obtain images of inorganic salt solid particles, analyze changes in particle size and sphericity, and monitor the sphericification process. Adjust the solvent addition rate of the injection pump, the vibration parameters of the vibration system, and the stirring speed of the stirring system according to the monitoring results to control the dissolution rate and the spheroidization effect; S5. When the sphericity of the particles reaches the preset target value, remove the inorganic salt solid particles, stop the liquid feeding, turn off the stirring system and vibration system in sequence, open the valve at the bottom of the lower storage tank, drain the solution and clean the entire device.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention has a simple structure, is sturdy and durable, facilitates observation of particle changes, and has excellent practicality; 2. This invention is environmentally friendly, resource-saving, and enables continuous preparation of inorganic salt spherical particles without pollution; 3. By using a stirring system and a vibration system, the sphericity of the particles can be controlled by adjusting the stirring and vibration parameters; by controlling the parameters of the injection pump, the inlet flow rate can be strictly controlled, thereby controlling the concentration field of particle dissolution and achieving accurate control of the particle size and sphericity of inorganic salt spherical particles. 4. It offers high operational safety and flexibility. By promptly removing saturated solutions, potential hazards caused by liquid accumulation can be avoided. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a top view of the present invention.

[0016] Explanation of reference numerals in the attached drawings: 1. Vibrator; 2. Lower liquid storage tank; 3. Upper liquid storage tank; 4. Particle vibration plate; 5. Connecting plate; 6. Support device; 7. Stirring shaft; 8. Stirring paddle; 9. Inlet pipe; 10. Injection pump; 11. Valve; 12. Aluminum profile frame; 13. Pulley; 14. Micropore. Detailed Implementation

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The specific implementation methods of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Example 1;

[0019] like Figure 1 As shown, this embodiment provides an inorganic salt solid particle spheroidization device, which includes a signal generation system, a vibration system, a stirring system, a dissolving system and an image analysis system connected in sequence.

[0020] The signal generation system is used to provide vibration signals, including a signal generator, a power amplifier, and an oscilloscope; the signal generator generates vibration signals, which are amplified by the power amplifier to drive the exciter; the oscilloscope is used to detect the vibration waveform.

[0021] The vibration system includes a vibrator 1, a lower liquid storage tank 2, an upper liquid storage tank 3, and a particle vibration plate 4 positioned between the lower and upper liquid storage tanks 2 and 3. The vibrator 1 receives vibration signals from the signal generation system and drives the entire vibration system to vibrate. The particle vibration plate 4 has micropores 14 that allow solution flow but block solid particles. The micropores 14 are 1 mm in size, ensuring that particles do not fall out while allowing a portion of the saturated solution to continuously flow out to the lower liquid storage tank 2 through the micropores 14. The vibration system also includes a connecting plate 5 and a support device 6. The vibrator 1 is positioned at the center of the support device 6. The connecting plate 5 is fixed to the lower liquid storage tank 2 and connected to the vibration position of the vibrator 1. The connecting plate 5 is also equipped with pulleys 13 via an aluminum profile frame 12, allowing it to move in sync with the vibration frequency of the vibrating device. The particle vibration plate 4 is mounted on top of the lower liquid storage tank 2; the upper liquid storage tank 3 is placed on the particle vibration plate 4.

[0022] The stirring system is installed in the upper liquid storage tank 3 to promote the flow of fluid in the upper liquid storage tank 3 and promote preferential dissolution in areas with larger specific surface areas. It includes a stirring shaft 7 and a stirring paddle 8 installed therewith. The stirring shaft 7 is positioned corresponding to the vibrator 1. The stirring paddle 8 is either a double-bladed integrated paddle or a turbine paddle.

[0023] The vibration system and the stirring system work together to turn the saturated solution into an unsaturated solution by adding a small amount of solvent. By adding external forces (stirring and convection), the velocity field and concentration field of the fluid flow are affected, which in turn affects the fluid concentration near the particle surface and thus affects the dissolution location and rate of the inorganic salt solid particles.

[0024] The dissolving system includes a solvent inlet located on the side of the upper storage tank 3 and a solvent outlet located on the bottom of the lower storage tank 2, used for adding solvent to the stirring system and discharging the solution. The solvent inlet is connected to an injection pump 10 via an inlet pipe 9; the distance between the inlet pipe 9 and the central axis of the upper storage tank 3 is 5 cm; a valve 11 is also installed at the solvent outlet.

[0025] The image analysis system includes an industrial camera for capturing images of solid particles, a panel light source for providing illumination, and a data processing unit for analyzing the images to obtain particle sphericity.

[0026] Example 2;

[0027] This embodiment is based on the inorganic salt solid particle spheroidizing device described in Embodiment 1, and its usage method is as follows: S1. Prepare a saturated solution and place it together with the inorganic salt solid particles to be spherized in the upper storage tank, and close the valve at the bottom of the lower storage tank so that the saturated solution completely submerges the inorganic salt solid particles. S2. Connect the injection pump to the inlet pipe, turn on the oscilloscope, signal generator and power amplifier in sequence, set the required vibration frequency and amplitude parameters, and drive the vibration system to start working, so that the inorganic salt solid particles generate regular vibration and mutual friction on the particle vibration plate. At the same time, turn on the stirring paddle switch, start the stirring system, set the stirring speed, so that the saturated solution in the upper storage tank will flow, disturb the inorganic salt solid particles and promote fluid mixing; S3. Solvent is added to the saturated solution system in the upper storage tank through an injection pump to turn the saturated solution into an unsaturated solution. This causes the edges and corners of the inorganic salt solid particles to dissolve first, thereby increasing the sphericity of the particles. The unsaturated solution then becomes a saturated solution again. At the same time, the enriched solution produced during the dissolution process flows into the lower storage tank through the particle vibration plate. S4. After stirring for 3-4 minutes, stop feeding and stirring. Use an image analysis system to obtain images of inorganic salt solid particles, analyze changes in particle size and sphericity, and monitor the sphericification process. Adjust the solvent addition rate of the injection pump, the vibration parameters of the vibration system, and the stirring speed of the stirring system according to the monitoring results to control the dissolution rate and the spheroidization effect; S5. When the sphericity of the particles reaches the preset target value, remove the inorganic salt solid particles, stop the liquid feeding, turn off the stirring system and vibration system in sequence, open the valve at the bottom of the lower storage tank, drain the solution and clean the entire device.

[0028] The dissolution rate of inorganic salt solid particles is related to the concentration field and velocity field near the inorganic salt particles in the saturated solution. The dissolution rate of inorganic salt particles is: ; Where R is the dissolution rate (mol / s); k is the mass transfer coefficient (m / s); A is the particle surface area (m²); Cs is the particle surface saturation concentration (mol / m³); and Cb is the bulk fluid concentration (mol / m³).

[0029] The mass transfer coefficient k is coupled to the velocity field and the concentration field, and is represented by the Sherwood number. ; Where Re is the Reynolds number; Sc is the Schmidt number; d is the characteristic length (e.g., particle diameter, m); and D is the solute diffusion coefficient (m² / s).

[0030] Example 3:

[0031] This embodiment is a further supplement to the previous embodiment. The industrial camera in the image analysis system uses a 2000w pixel lens as an example. It divides the image frame into 5472x3648 grids, and each grid corresponds to one pixel. The higher the pixel count of the image captured by the same size particle, the higher the recognition of image details.

[0032] Furthermore, the image analysis system includes a lens with a specific focal length. The lens determines the camera's image size and depth of field. During focusing, only one plane is truly in focus. In the out-of-focus state, the object plane is either in front of or behind the focal plane. Light emitted from a point on the object at different angles falls on the image plane, forming a blurred circle called the circle of confusion. If the diameter of the circle of confusion is smaller than the sensor pixel size, this circle of confusion is called the permissible circle of confusion. There is a distance in front of, behind, and in the depth of the focal plane, and the image falls within the permissible range of the circle of confusion; this distance is called the depth of field. When photographing solid particles, the shooting distance is 22cm, and the lens depth of field is controlled to be less than 2mm. After adjusting the specific position of the particles, the image acquisition requirements for all six sides of the inorganic salt solid particles can be met during shooting.

[0033] The captured images of inorganic salt solid particles are transmitted to a computer via an HDMI interface and saved to the hard drive. The data processing unit opens the image, calibrates the pixels corresponding to the smallest division value of 0.1mm on the rectangular micrometer, thereby realizing the conversion between image pixels and actual particle size, measuring parameters such as particle size, isotropic diameter, perimeter, and area, and then calculating the sphericity of the particles.

[0034] The above embodiments are for illustrative purposes only and are not intended to limit the scope of this invention. Although this invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of this invention do not depart from the spirit and scope of the technical solutions of this invention and should be covered within the scope of the claims of this invention.

Claims

1. A device for spheroidizing inorganic salt solid particles, characterized in that, It includes a signal generation system, a vibration system, a stirring system, and a dissolving system connected in sequence; The signal generation system is used to provide vibration signals; The vibration system includes a vibrator, a lower liquid storage tank, an upper liquid storage tank, and a particle vibration plate disposed between the lower and upper liquid storage tanks; the vibrator receives vibration signals from the signal generation system and drives the entire vibration system to vibrate; the particle vibration plate is provided with micropores that allow solution flow but block solid particles. The stirring system is installed in the upper liquid storage tank to promote fluid flow in the upper liquid storage tank and promote preferential dissolution in areas with larger specific surface areas; The dissolving system includes a solvent inlet located on the side of the upper storage tank and a solvent outlet located on the bottom of the lower storage tank, for adding solvent to the stirring system and discharging solution.

2. The device for spheroidizing inorganic salt solid particles according to claim 1, characterized in that, The signal generation system includes a signal generator, a power amplifier, and an oscilloscope; the signal generator generates a vibration signal, which is amplified by the power amplifier and then drives the exciter; the oscilloscope is used to detect the vibration waveform.

3. The inorganic salt solid particle spheroidization device according to claim 2, characterized in that, The vibration system also includes a connecting plate and a support device; the vibrator is located at the center of the support device; the connecting plate is fixed to the lower liquid storage tank and connected to the vibration position of the vibrator; the particle vibration plate is installed on the top of the lower liquid storage tank; the upper liquid storage tank is placed on the particle vibration plate.

4. The device for spheroidizing inorganic salt solid particles according to claim 3, characterized in that, The stirring system includes a stirring shaft and a stirring blade installed therewith; the stirring shaft is positioned corresponding to the vibrator; the stirring blade is either a double-bladed integrated blade or a turbine blade.

5. The device for spheroidizing inorganic salt solid particles according to claim 4, characterized in that, The solvent inlet is connected to an injection pump via an inlet pipe; the distance between the inlet pipe and the central axis of the upper storage tank is 5 cm; and a valve is also installed at the solvent outlet.

6. The device for spheroidizing inorganic salt solid particles according to claim 5, characterized in that, It also includes an image analysis system; the image analysis system includes an industrial camera for capturing images of solid particles, a panel light source for providing illumination, and a data processing unit for analyzing the images to obtain particle sphericity.

7. The device for spheroidizing inorganic salt solid particles according to claim 6, characterized in that, Its usage method is as follows: S1. Prepare a saturated solution and place it together with the inorganic salt solid particles to be spherized in the upper storage tank, and close the valve at the bottom of the lower storage tank so that the saturated solution completely submerges the inorganic salt solid particles. S2. Connect the injection pump to the inlet pipe, turn on the oscilloscope, signal generator and power amplifier in sequence, set the required vibration frequency and amplitude parameters, and drive the vibration system to start working, so that the inorganic salt solid particles generate regular vibration and mutual friction on the particle vibration plate. At the same time, turn on the stirring paddle switch, start the stirring system, set the stirring speed, so that the saturated solution in the upper storage tank will flow, disturb the inorganic salt solid particles and promote fluid mixing; S3. Solvent is added to the saturated solution system in the upper storage tank through an injection pump to turn the saturated solution into an unsaturated solution. This causes the edges and corners of the inorganic salt solid particles to dissolve first, thereby increasing the sphericity of the particles. The unsaturated solution then becomes a saturated solution again. At the same time, the enriched solution produced during the dissolution process flows into the lower storage tank through the particle vibration plate. S4. After stirring for 3-4 minutes, stop feeding and stirring. Use an image analysis system to obtain images of inorganic salt solid particles, analyze changes in particle size and sphericity, and monitor the sphericification process. Adjust the solvent addition rate of the injection pump, the vibration parameters of the vibration system, and the stirring speed of the stirring system according to the monitoring results to control the dissolution rate and the spheroidization effect; S5. When the sphericity of the particles reaches the preset target value, remove the inorganic salt solid particles, stop the liquid feeding, turn off the stirring system and vibration system in sequence, open the valve at the bottom of the lower storage tank, drain the solution and clean the entire device.

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