Superfine magnesium hydroxide dispersing device with magnetic stirring function

Abstract

The superfine magnesium hydroxide dispersing device comprises a stock bin (2), a motor (3), a driving magnetic stirring rotor (4), a driven magnetic stirring rotor (5), an air compressor (6), a dryer (7), a flow valve (8), a nozzle (9) and a storage container (10). A feeding hole (1) is formed in the top of the stock bin; the driven magnetic stirring rotor is mounted at the bottom of the stock bin; the driving magnetic stirring rotor is mounted on a motor shaft extension; the lower part of the stock bin is connected with a dryer through a pipeline with a flow valve; the input end of the dryer is connected with an air compressor; the upper part of the stock bin is connected with a nozzle through a pipeline and extends into the storage container; a discharge hole (11) is formed in the bottom of the storage container. Compressed air provided by the air compressor is dried by the dryer and then enters the stock bin filled with superfine magnesium hydroxide powder through the flow valve, and the stirred powder floats, flows out of the stock bin along with gas flow, enters the storage container through the nozzle and acts on dispersion of nano-particles.

Description

Technical Field

[0001] This utility model relates to an ultrafine magnesium hydroxide dispersion device with magnetic stirring, belonging to the field of powder dispersion technology. Background Technology

[0002] Magnesium hydroxide is a recognized excellent flame retardant in the rubber and plastics industry, possessing the triple functions of flame retardancy, smoke suppression, and filling. It is a white powder, non-toxic, odorless, highly stable, non-volatile, with a high decomposition temperature, and does not corrode equipment. It is the preferred material for achieving halogen-free flame retardancy in organic polymers and can be widely used in plastics and rubbers such as PP, PE, PVC, EVA, PS, HIPS, and ABS as a flame retardant or flame-retardant filler.

[0003] Compared to coarse-grained magnesium hydroxide powder, ultrafine magnesium hydroxide exhibits superior flame retardant and smoke-suppressing effects, effectively improving the mechanical properties of plastics. However, the large specific surface area and high specific surface energy of ultrafine magnesium hydroxide make its thermodynamic properties highly unstable. Therefore, particle agglomeration is highly likely during preparation and application, leading to increased particle size and the loss of its unique properties. The size of ultrafine particles significantly impacts their performance; therefore, before using ultrafine magnesium hydroxide, it should be dispersed back to its original particle size to fully utilize its advantages of large specific surface area and high activity at the ultrafine scale. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that ultrafine magnesium hydroxide is prone to particle agglomeration during preparation and application, which causes the ultrafine particles to lose their unique properties. This invention proposes an ultrafine magnesium hydroxide dispersion device with magnetic stirring.

[0005] The technical solution of this utility model is as follows: an ultrafine magnesium hydroxide dispersion device with magnetic stirring, comprising a silo, a motor, an active magnetic stirring rotor, a driven magnetic stirring rotor, an air compressor, a dryer, a flow valve, a nozzle, and a storage container.

[0006] The silo is a vertical cylindrical structure with a feed inlet at the top. The driven magnetic stirring rotor is installed at the bottom of the silo. The active magnetic stirring rotor is installed on the motor shaft extension below the driven magnetic stirring rotor. The lower part of the silo is connected to the output end of the dryer through a pipe with a flow valve, and the input end of the dryer is connected to an air compressor. The upper part of the silo is connected to a nozzle that extends into a storage container through a pipe, and the storage container has a discharge port at the bottom. The compressed air provided by the air compressor is dried by the dryer and then enters the silo containing ultrafine magnesium hydroxide powder through the flow valve. The powder is stirred up and floats up, flowing out of the silo with the gas flow and entering the storage container through the nozzle.

[0007] The driven magnetic stirring rotor is installed at the bottom center of the silo; the axis of the active magnetic stirring rotor located below the driven magnetic stirring rotor coincides with the axis of the driven magnetic stirring rotor on the same vertical line.

[0008] The storage container is a sealed horizontal cylindrical tank. The nozzle extending into the storage container can disperse the agglomerates of ultrafine magnesium hydroxide powder particles after they are sprayed out.

[0009] The nozzle has a microporous structure, and the powder agglomerates are dispersed by the high-speed airflow through the nozzle.

[0010] The working principle of this device is as follows: the dispersion principle of ultrafine magnesium hydroxide powder agglomerates mainly utilizes the shear force generated by the release of high-pressure gas through micropores to break down the powder particle agglomerate structure; the pressure difference across the micropore nozzle is key to dispersion. The airflow forms a jet as it passes through the nozzle, and the velocity gradient between the axis and the wall surface, as well as the velocity change of the high-speed airflow after exiting the nozzle, both contribute to the dispersion of the nanoparticles. The storage container provides sufficient space for the release of the high-pressure airflow from the nozzle, allowing the gas pressure to decrease rapidly and providing conditions for generating shear force.

[0011] The beneficial effects of this invention are as follows: the device uses a dried airflow to spray ultrafine magnesium hydroxide powder through a nozzle into a storage container. The airflow forms a jet as it passes through the nozzle. The velocity gradient between the axis and the wall surface, as well as the velocity change of the high-speed airflow after exiting the nozzle, all contribute to the dispersion of the nanoparticles. This effectively disperses agglomerates of ultrafine magnesium hydroxide powder particles, ensuring the advantage of the powder's small size. Furthermore, the magnetic stirring rotor causes the ultrafine powder to float, allowing the airflow to better carry and disperse the powder. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the device of this utility model;

[0013] In the diagram, 1 is the feed inlet; 2 is the hopper; 3 is the motor; 4 is the active magnetic stirring rotor; 5 is the driven magnetic stirring rotor; 6 is the air compressor; 7 is the dryer; 8 is the flow valve; 9 is the nozzle; 10 is the storage container; and 11 is the discharge outlet. Detailed Implementation

[0014] The specific embodiments of this utility model are as follows: Figure 1 As shown.

[0015] like Figure 1 As shown, this embodiment of an ultrafine magnesium hydroxide dispersion device with magnetic stirring includes a silo 2, a motor 3, an active magnetic stirring rotor 4, a driven magnetic stirring rotor 5, an air compressor 6, a dryer 7, a flow valve 8, a nozzle 9, and a storage container 10.

[0016] After the ultrafine magnesium hydroxide enters the silo 2 through the feed inlet 1, the motor 3 starts and drives the main magnetic stirring rotor 4 to rotate. Under the drive of the active magnetic stirring rotor 4, the driven magnetic stirring rotor 5 rotates and stirs the nanoparticles in the container, causing the stirred powder to float. At the same time, the compressed air provided by the air compressor 6 is dried by the dryer 7 and then enters the silo 2 containing the ultrafine magnesium hydroxide powder through the flow valve 8. The stirred powder floats up and flows out of the silo 2 with the gas flow, passing through the nozzle 9 and entering the storage container 10. The airflow carrying the ultrafine powder is under high pressure before the nozzle 9 outlet. The high-pressure airflow expands and decelerates at the outlet after leaving the nozzle 9. After leaving the nozzle 9, the airflow pressure drops sharply. This rapid change in pressure causes a similarly drastic change in the airflow at the outlet. The powder particles in the flow field are also subject to the force caused by the change in gas velocity. When the magnitude of the force reaches a level comparable to the van der Waals force of the nanoparticles, it can disperse the agglomerates of ultrafine magnesium hydroxide particles. The well dispersed ultrafine magnesium hydroxide powder is discharged through the discharge port 11 at the bottom of the storage container 10 and enters the packaging stage.

[0017] The dispersion principle of ultrafine magnesium hydroxide powder agglomerates mainly utilizes the shear force generated by the release of high-pressure gas through micropores. The pressure difference across the micropore nozzle is crucial for dispersion. The airflow through nozzle 9 forms a jet, and the velocity gradient between the axis and the wall, as well as the velocity change of the high-speed airflow after exiting the nozzle, both contribute to the dispersion of the nanoparticles. The storage container 10 provides sufficient space for the release of the high-pressure gas from the nozzle, allowing the gas pressure to decrease rapidly and creating conditions for shear force generation.

Claims

1. An ultrafine magnesium hydroxide dispersing apparatus with magnetic stirring, characterized by, The device comprises a bin, a motor, a driving magnetic stirring rotor, a driven magnetic stirring rotor, an air compressor, a dryer, a flow valve, a nozzle and a storage container. The bin is a vertical cylindrical structure with a feeding port at the top, and the driven magnetic stirring rotor is installed at the bottom of the bin; the driving magnetic stirring rotor is installed on the motor shaft extending from the lower part of the driven magnetic stirring rotor; the lower part of the bin is connected to the output end of the dryer through a pipeline with a flow valve, and the input end of the dryer is connected to the air compressor; the upper part of the bin is connected to the nozzle extending into the storage container through a pipeline, and the bottom of the storage container is provided with a discharging port; the compressed air provided by the air compressor is dried by the dryer, then passes through the flow valve and enters the bin containing superfine magnesium hydroxide powder, the agitated powder floats up and flows out of the bin along with the gas, and then passes through the nozzle and enters the storage container.

2. The superfine magnesium hydroxide dispersing device with magnetic stirring according to claim 1, characterized in that, The driven magnetic stirring rotor is installed at the center of the bottom of the bin; the axis of the driving magnetic stirring rotor below the driven magnetic stirring rotor is on the same vertical line with the axis of the driven magnetic stirring rotor.

3. The superfine magnesium hydroxide dispersing device with magnetic stirring according to claim 1, characterized in that, The storage container is a sealed horizontal cylindrical tank, and the nozzle extending into the storage container can disperse the agglomerates of superfine magnesium hydroxide particles after spraying the superfine magnesium hydroxide particles.

4. The superfine magnesium hydroxide dispersing device with magnetic stirring according to claim 1, characterized in that, The nozzle has a microporous structure, and the high-speed airflow passing through the nozzle can disperse the powder agglomerates.

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