A device and method for preparing magnesium oxide nanoparticles

Abstract

The application relates to a preparation device and method of magnesium oxide nanoparticles, and belongs to the technical field of magnesium oxide preparation, which comprises a screening bin, two screen mesh pieces capable of deflecting around horizontal shafts are arranged in the screening bin in a vertical direction, upper and lower discharge ports are respectively arranged in the two side walls of the screening bin and correspond to the two screen mesh pieces, movable flaps are movably arranged in each discharge port, a follow-up opening and closing assembly and a synchronous driving piece are further arranged, the follow-up opening and closing assembly comprises a hinged piece and a follow-up transmission piece, the linkage design of the follow-up opening and closing assembly and the screen mesh piece enables the corresponding side discharge port to be automatically opened when the screen mesh is deflected to discharge, and the discharge port is quickly closed under the action of a torsional spring when the screen mesh is reset, so that the impurities and coarse particles are automatically discharged, manual operation of the flap is not needed, the labor intensity of workers is effectively reduced, material leakage in the screening process is avoided, and the accuracy and continuity of the grading and screening are ensured.

Description

Technical Field

[0001] This invention belongs to the field of magnesium oxide preparation technology, specifically relating to an apparatus and method for preparing magnesium oxide nanoparticles. Background Technology

[0002] Magnesium oxide nanoparticles exhibit excellent application performance in multiple fields such as catalysis, ceramics, electronics, and environmental protection due to their unique nanoscale effects. The refinement and efficiency of their preparation process have become the focus of industry research. Among them, sieving and separation is an important step in the preparation process of magnesium oxide nanoparticles, which directly determines the particle size uniformity, purity, and subsequent application effects of the finished particles. Therefore, high requirements are placed on the classification accuracy, sieving efficiency, and automation level of sieving devices.

[0003] Existing magnesium oxide nanoparticle sieving devices mostly adopt single-layer or fixed double-layer screen structures, which not only have poor grading effect and make it difficult to achieve accurate separation of particles of different sizes, but also generally suffer from problems such as easy screen clogging and the need for manual cleaning and removal of impurities and coarse particles. This leads to frequent interruptions in sieving operations, low automation levels, and high labor intensity for workers. At the same time, traditional devices lack a linkage deflection and synchronous discharge design for the screen, making it impossible to coordinate the sieving and discharge processes, which reduces overall production efficiency and makes it difficult to meet the needs of continuous industrial production. Therefore, there is a need for a magnesium oxide nanoparticle preparation device and method. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for preparing magnesium oxide nanoparticles that can continuously screen and discharge materials and are not prone to clogging, in order to solve the above-mentioned problems.

[0005] The present invention achieves the above objectives through the following technical solutions:

[0006] An apparatus for preparing magnesium oxide nanoparticles includes a sieving chamber, wherein two screens rotatable about a horizontal axis are arranged vertically at intervals within the sieving chamber, and two discharge ports are respectively opened on both side walls of the sieving chamber corresponding to the two screens. A movable baffle is movably embedded in each discharge port. The apparatus further includes:

[0007] The follow-up opening and closing assembly includes a hinge and a follow-up transmission component. The upper end of the movable baffle is hinged to the side wall of the screening chamber through the hinge. The two ends of the follow-up transmission component are respectively connected to the movable baffle and the screen component. When one end of the screen component deflects downward, the follow-up transmission component synchronously drives the movable baffle on the corresponding side to open.

[0008] A synchronous drive unit is connected to both screen components and is used to drive the same end of the two screen components to deflect synchronously in opposite directions, so as to realize the alternating tilting and screening of the screen components.

[0009] As a further optimization of the present invention, the two screen components are a first screen and a second screen, the first screen is located above the second screen, and the aperture of the first screen is larger than that of the second screen.

[0010] As a further optimization of the present invention, the hinge includes a protrusion fixed to the side wall of the screening chamber, a first connecting rod fixedly connected between two adjacent protrusions, a sleeve rotatably sleeved on the outside of the first connecting rod, and a connecting plate connected between the outer wall of the sleeve and the movable baffle.

[0011] As a further optimization of the present invention, a torsion spring is also provided on the outside of the first connecting rod, one end of the torsion spring abutting against the protrusion and the other end abutting against the sleeve.

[0012] As a further optimization of the present invention, the follower transmission component includes:

[0013] The first protrusion is fixed to the outer wall of the screening chamber, and a guide rod is provided at the end of the first protrusion;

[0014] The second protrusion is fixed to the lower end of the outer wall of the movable baffle. A pull rope is connected between the second protrusion and the frame of the screen, and the pull rope is arranged to pass around the guide rod.

[0015] As a further optimization of the present invention, a vertical clearance groove is provided at the side wall where the pull rope passes through the screening chamber.

[0016] As a further optimization of the present invention, the synchronous drive component includes a drive motor and a second connecting rod. A second connecting rod is connected to the middle of the side of both the first screen and the second screen. The output end of the drive motor is installed at the end of one of the second connecting rods, and gears are installed on the outside of each of the second connecting rods. A rack is meshed between the two gears to realize the opposite synchronous rotation of the two second connecting rods.

[0017] As a further optimization of the present invention, the synchronous drive component further includes a guide frame fixed to the outer wall of the screening chamber, and the rack slides through the guide frame.

[0018] As a further optimization of the present invention, it also includes an upper top assembly, which is symmetrically installed on both sides of the upper end face of the second screen. Each side of the upper top assembly includes a plurality of top rods spaced apart along the length direction of the second screen. From the end to the middle of the second screen, the height of each top rod increases in a gradient. Each top rod includes a connecting strip, and a plurality of top rods are fixed at equal intervals along the length direction of the upper end face of the connecting strip.

[0019] A method for preparing magnesium oxide nanoparticles, using the magnesium oxide nanoparticle preparation apparatus described above, includes the following steps:

[0020] S1. The magnesium oxide nanoparticle raw material to be graded and screened is fed into the top feed port of the screening chamber. The raw material first falls onto the upper surface of the first screen located above. After preliminary screening by the first screen, the particles that meet the pore size requirements fall onto the second screen below for secondary fine screening.

[0021] S2. During the screening process, the drive motor is periodically started and its forward and reverse rotation is controlled. The output end of the drive motor drives one of the second connecting rods to rotate. Through the meshing transmission of gears and racks, the other second connecting rod is driven to rotate synchronously in the opposite direction. This drives the same end of the first screen and the second screen to deflect downward in opposite directions. When one end of the screen deflects downward, the pull rope pulls the second protrusion on the corresponding side, causing the movable baffle to flip outward around the first connecting rod, opening the discharge port at the corresponding position, and discharging impurities or coarse particles that cannot pass through the screen holes. When the drive motor reverses, the screen deflects in the opposite direction, and the torsion spring drives the movable baffle to quickly reset and close the discharge port. This cycle is repeated to achieve continuous grading and screening and automatic discharge of impurities.

[0022] S3. When the same end of the first screen and the second screen approaches each other, the anti-clogging top component at the upper end of the second screen rises synchronously, and the top rod presses against the lower end face of the first screen, causing the first screen to vibrate slightly, effectively reducing the probability of screen hole clogging and ensuring screening efficiency.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. In this invention, by setting two layers of deflectable screens with different apertures in the screening chamber and cooperating with a synchronous drive to achieve reverse synchronous deflection of the same end of the two screens, a two-stage precise classification and screening of magnesium oxide nanoparticles is achieved. This effectively separates coarse impurities, medium and coarse particles, and nanoparticles that meet the particle size requirements, thereby improving the classification accuracy and purity of the finished particles and meeting the differentiated particle size requirements of magnesium oxide nanoparticles in different application scenarios.

[0025] 2. In this invention, the follow-up opening and closing component is linked with the screen component, so that the corresponding discharge port automatically opens when the screen deflects to discharge material, and the discharge port quickly closes under the action of the torsion spring when the screen resets. This realizes the automatic discharge of impurities and coarse particles without the need for manual operation of the baffle, effectively reducing the labor intensity of the workers, while avoiding material leakage during the screening process, and ensuring the accuracy and continuity of the grading screening.

[0026] 3. In this invention, the gradient-type top component set on the second screen can form a uniform and suitable top pressure vibration on the lower end face of the first screen during the screen deflection process. This effectively breaks the adsorption balance of material particles at the screen holes, shakes off the particles blocked in the screen holes, reduces the probability of screen blockage, ensures that the screen remains unobstructed, maintains the stable screening efficiency of the device, and at the same time, the smooth design of the top rod can avoid scratching the screen surface and wearing the screen holes, thus extending the service life of the screen. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the overall appearance and structure of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of the follow-up opening and closing component, the synchronous driving component, the first screen, the second screen and the upper top component of the present invention;

[0030] Figure 4 This is a front view of the follow-up opening and closing component, the first screen, the second screen, and the top component of the present invention;

[0031] Figure 5 This is a schematic diagram of the structure of the follow-up opening and closing component and the first screen of the present invention;

[0032] Figure 6 This is a schematic diagram of the opening and closing components and the movable baffle of the present invention;

[0033] Figure 7 This is the present invention. Figure 6 Enlarged diagram of point A in the diagram;

[0034] Figure 8 This is the present invention. Figure 1 Enlarged diagram of point B in the image.

[0035] In the diagram: 1. Screening bin; 2. Feed hopper;

[0036] 3. Discharge port; 31. Movable baffle;

[0037] 4. Follow-up opening and closing assembly; 41. Hinge; 411. Protrusion; 412. First connecting rod; 413. Sleeve; 414. Torsion spring; 415. Connecting plate; 42. Pull rope; 43. First protrusion; 44. Second protrusion; 45. Clearance groove;

[0038] 5. Synchronous drive component; 51. Drive motor; 52. Second connecting rod; 53. Gear; 54. Guide frame; 55. Rack;

[0039] 6. First screen; 7. Second screen;

[0040] 8. Top assembly; 81. Connecting strip; 82. Top rod. Detailed Implementation

[0041] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0042] Example: Figures 1 to 8 As shown, a device for preparing magnesium oxide nanoparticles includes a screening chamber 1 with a box structure. A feeding hopper 2 is installed at the top of the screening chamber 1, positioned near the center. The feeding hopper 2 has a funnel-shaped inlet design, facilitating quick and stable feeding of raw materials to be screened while preventing spillage onto the outside of the screening chamber 1. Inside the screening chamber 1, two screens are vertically spaced and can rotate around a horizontal axis. The two screens are arranged in parallel, with the spacing determined according to the grading requirements of the magnesium oxide nanoparticles to ensure proper screening of the upper screen. The selected material falls precisely onto the lower screen, preventing material accumulation or leakage. Both sides of the screening chamber 1 have two discharge ports 3 corresponding to the two screen components. These discharge ports 3 correspond to the inclined ends of the two screen components. Each discharge port 3 has a movable baffle 31 embedded within it. The movable baffle 31 fits tightly against the inner wall of the discharge port 3 and is made of wear-resistant sealing material, effectively preventing unscreened raw materials from overflowing from the discharge port 3, ensuring the continuity of the screening process. Additionally, a follow-up opening and closing assembly is included. The component 4 and the synchronous drive component 5, the follow-up opening and closing assembly 4 includes a hinge component 41 and a follow-up transmission component. The upper end of the movable baffle 31 is hinged to the side wall of the screening chamber 1 through the hinge component 41. The two ends of the follow-up transmission component are respectively connected to the movable baffle 31 and the screen component. When one end of the screen component deflects downward, the follow-up transmission component synchronously drives the movable baffle 31 on the corresponding side to open, so that the screened material on the screen component can be smoothly discharged through the discharge port 3. When the screen component returns to the horizontal position, the follow-up transmission component drives the movable baffle 31 to close synchronously, preventing subsequent unscreened materials from being discharged. The material is discharged in advance, and the discharge port 3 is opened and closed synchronously to ensure the accuracy of grading and screening. The synchronous drive component 5 is connected to both screen components and is used to drive the same end of the two screen components to deflect synchronously in opposite directions. That is, when the left end of the upper screen component deflects downward, the left end of the lower screen component deflects upward, and vice versa. Through this alternating tilting method, the two screen components are in an alternating state of screening and discharge, which not only improves the screening efficiency, but also enables the graded collection of particles of different sizes and avoids the mixing of particles of different sizes.

[0043] Among them, see Figure 1 and Figure 3As shown, the two screen components are a first screen 6 and a second screen 7. Both the first screen 6 and the second screen 7 consist of a screen and a mounting frame. The mounting frame is made of high-strength metal and serves to fix and support the screen, preventing deformation or damage during deflection. The screen is made of corrosion-resistant and wear-resistant precision filter. The first screen 6 is located above the second screen 7, and the aperture of the first screen 6 is larger than that of the second screen 7, which is used to achieve the classification and sieving of magnesium oxide nanoparticles.

[0044] See Figures 5-7 As shown, the hinge 41 includes a protrusion 411 fixed to the side wall of the screening chamber 1. A first connecting rod 412 is fixedly connected between two adjacent protrusions 411. A sleeve 413 is rotatably sleeved on the outside of the first connecting rod 412. The sleeve 413 can rotate flexibly around the first connecting rod 412 to provide support for the rotation of the movable baffle 31. A connecting plate 415 is connected between the outer wall of the sleeve 413 and the movable baffle 31. A torsion spring 414 is also provided on the outside of the first connecting rod 412. The torsion spring 414 is sleeved on the first connecting rod 412. One end of the torsion spring 414 abuts against the protrusion 411, and the other end abuts against the sleeve 413. The torsion spring 414 is always in a charged state. When the screen is reset and the tension of the follower transmission component disappears, the torsion spring 414 can quickly drive the sleeve 413 to rotate in the opposite direction, and then drive the movable baffle 31 to reset and close through the connecting plate 415, so as to realize the rapid reset of the movable baffle 31 and ensure the continuity of the screening process.

[0045] See Figures 4-6 as well as Figure 8 As shown, the follower transmission component includes a first protrusion 43 and a second protrusion 44. The first protrusion 43 is fixed to the outer wall of the screening chamber 1. A guide rod is provided at the end of the first protrusion 43. The guide rod is rotatable and its surface is smoothed to reduce friction between the pull rope 42 and the guide rod, thus extending the service life of the pull rope 42. The second protrusion 44 is fixed to the lower end of the outer wall of the movable baffle 31. A pull rope 42 connects the second protrusion 44 and the mounting frame of the screen component. The pull rope 42 is made of high-strength, corrosion-resistant material. The nylon rope ensures that it will not break during long-term use. The pull rope 42 is set around the guide rod, which changes the transmission direction of the pull rope 42 so that the tension generated when the screen part deflects can be transmitted to the movable baffle 31. The pull rope 42 has a vertical avoidance groove 45 at the side wall of the screening chamber 1 to avoid the displacement of the pull rope 42 when the screen part deflects. When the end of the screen part moves down, the pull rope 42 can be used to pull the second protrusion 44. When the end of the screen part moves up, the pull rope 42 does not pull the second protrusion 44.

[0046] See Figures 1-3As shown, the synchronous drive component 5 includes a drive motor 51 and a second connecting rod 52. The drive motor 51 is a reversible motor with adjustable speed and stable power. It can flexibly adjust the deflection frequency and amplitude of the screen components according to the screening requirements. A second connecting rod 52 is connected to the middle of the side of the first screen 6 and the second screen 7. The output end of the drive motor 51 is installed at the end of one of the second connecting rods 52 through a coupling to provide power for the deflection of the screen components. Gears 53 are installed on the outside of the second connecting rods 52. A rack 55 is meshed between the two gears 53. The rack 55 has protruding teeth on both sides near the end. Each protruding tooth corresponds to the opposite gear 53 to realize the reverse synchronous deflection of the two second connecting rods 52.

[0047] The synchronous drive component 5 also includes a guide frame 54 fixed to the outer wall of the screening chamber 1. The guide frame 54 can be a metal frame structure. The rack 55 is slidably inserted through the guide frame 54. The guide frame 54 plays a limiting and guiding role in the movement direction of the rack 55, preventing the rack 55 from deviating or jamming during the meshing transmission process, ensuring the accuracy of the reverse synchronous rotation of the two gears 53, and thus ensuring the alternating tilting screening effect of the screen component.

[0048] As described above, in practical use, the staff first put the magnesium oxide nanoparticle raw material to be graded into the screening chamber 1 from the feeding hopper 2. The raw material falls smoothly under the action of gravity and initially falls on the first screen 6 above. At this time, both screens are in a horizontal state. The movable baffle 31 is kept closed under the action of the torsion spring 414 to prevent the raw material from being discharged directly from the discharge port 3. Then, the staff starts the drive motor 51 in the synchronous drive component 5. The drive motor 51 drives the second connecting rod 52 connected to it to rotate. The second connecting rod 52 drives the gear 53 outside it to rotate synchronously. Through the meshing transmission of the rack 55, the other gear 53 rotates in the opposite direction, which in turn drives the other second connecting rod 52 to rotate synchronously in the opposite direction, so that the same end of the first screen 6 and the second screen 7 deflects in opposite directions. Assuming that the left end of the first screen 6 deflects downward and the right end lifts upward, then the left end of the second screen 7 lifts upward and the right end deflects downward.

[0049] When the left end of the first screen 6 deflects downward, its mounting frame simultaneously pulls the connected pull rope 42. After the pull rope 42 passes around the guide rod and changes the transmission direction, it pulls the second protrusion 44 downward, thereby causing the movable baffle 31 to rotate around the first connecting rod 412 of the hinge 41, opening the discharge port 3 on the upper left side of the screening chamber 1. At this time, the magnesium oxide nanoparticle raw material falling on the first screen 6, under the action of the tilt angle of the first screen 6, the coarse particles or impurities with a particle size larger than the screen holes of the first screen 6 slide along the inclined surface and are discharged through the discharge port 3 opened on the upper left side, completing the coarse screening; while the magnesium oxide particles with a particle size smaller than the screen holes of the first screen 6 pass smoothly through the screen holes of the first screen 6 and fall onto the second screen 7 below. Meanwhile, the second screen 7 is in a downward tilted state at the right end. Its mounting frame pulls the corresponding pull rope 42, which, through the guide rod transmission, pulls the movable baffle 31 on the lower right side to open. The particles falling on the second screen 7, under the tilting action, the medium and coarse particles with a particle size larger than the screen holes of the second screen 7 slide along the inclined surface and are discharged through the discharge port 3 on the lower right side; while the magnesium oxide nanoparticles with the required particle size pass through the screen holes of the second screen 7 and fall to the bottom of the screening chamber 1. The workers can collect the purified nanoparticles through the discharge port (not shown) set at the bottom of the screening chamber 1. The mounting base can be set on both sides of the bottom of the screening chamber 1 to raise the bottom of the screening chamber 1 to facilitate the collection of magnesium oxide nanoparticles.

[0050] When the output of the drive motor 51 rotates, causing the two second connecting rods 52 to rotate in opposite directions to a certain angle, the deflection directions of the first screen 6 and the second screen 7 switch. The right end of the first screen 6 deflects downward and the left end lifts upward, while the right end of the second screen 7 lifts upward and the left end deflects downward. At this time, the tension of the pull rope 42 at the left end of the first screen 6 disappears, and the torsion spring 414 quickly resets, causing the movable baffle 31 on the upper left side to close. Meanwhile, the pull rope 42 at the right end of the first screen 6 is pulled, causing the movable baffle 31 on the upper right side to open. The coarse particles remaining on the first screen 6 are discharged along the inclined surface on the right end through the discharge port 3 on the upper right side. Similarly, the pull rope 42 at the right end of the second screen 7... 2. When the pulling force disappears, the movable baffle 31 on the lower right side closes under the action of the torsion spring 414, and the movable baffle 31 on the lower left side is pulled open. The medium and coarse particles remaining on the second screen 7 are discharged through the discharge port 3 on the lower left side along the inclined surface on the left end. This cycle repeats, and the synchronous drive component 5 drives the two screen components to tilt alternately. The follow-up opening and closing component 4 synchronously controls the opening and closing of the corresponding discharge port 3 to realize the continuous classification and screening of magnesium oxide nanoparticles. This not only improves the screening efficiency, but also accurately separates particles of different sizes, ensuring the purity and classification effect of magnesium oxide nanoparticles. The whole process does not require frequent manual operation of the movable baffle 31, and has a high degree of automation, effectively reducing the labor intensity of the staff.

[0051] See Figure 1 as well as Figures 3-4As shown, the preparation device for magnesium oxide nanoparticles also includes an upper top assembly 8, which is symmetrically installed on both sides of the upper end face of the second screen 7. Each upper top assembly 8 includes multiple top rods spaced apart along the length of the second screen 7. From the end to the middle of the second screen 7, the height of each top rod increases in a gradient. This gradient design is highly compatible with the deflection trajectory of the second screen 7: when the second screen 7 deflects under the drive mechanism, the deflection amplitude in the middle is usually smaller than that at the end. The gradient-increasing top rods can make the pressure on each part of the lower end face of the first screen 6 match the deflection amplitude, ensuring that the pressure action is more in line with the actual working state and avoiding damage to the screen due to insufficient or excessive local pressure. The top rods include connecting strips 81, which are made of high strength. Made of corrosion-resistant material, the upper end face of the connecting bar 81 is fixed with multiple push rods 82 at equal intervals along its length. The push rods 82 are made of hard and wear-resistant material with rounded ends to avoid scratching the screen surface of the first screen 6 during the pressing process, and to reduce wear on the edges of the screen holes. During the screen deflection process, the push rods 82 press against the lower end face of the first screen 6, causing the first screen 6 to vibrate slightly up and down. This can effectively break the adsorption balance of material particles at the screen holes, prevent magnesium oxide nanoparticles and a small amount of impurities generated during the preparation process from clogging the screen holes, and avoid affecting the material screening efficiency and preparation quality. The periodic pressing vibration of the push rods 82 can shake off the particles adsorbed in the screen holes, ensuring that the screen holes are always unobstructed and ensuring the continuous and stable operation of the entire screening device.

[0052] This invention also proposes a method for preparing magnesium oxide nanoparticles, using the aforementioned magnesium oxide nanoparticle preparation apparatus, comprising the following steps:

[0053] S1. The magnesium oxide nanoparticle raw material to be graded and screened is fed into the top feed port of the screening chamber 1. The raw material first falls onto the upper surface of the first screen 6 located above. After preliminary screening by the first screen 6, the particles that meet the pore size requirements fall onto the second screen 7 below for secondary fine screening.

[0054] S2. During the screening process, the drive motor 51 is periodically started and its forward and reverse rotation is controlled. The output end of the drive motor 51 drives one of the second connecting rods 52 to rotate. Through the meshing transmission of the gear 53 and the rack 55, the other second connecting rod 52 is driven to rotate synchronously in the opposite direction, thereby driving the same end of the first screen 6 and the second screen 7 to deflect downward in opposite directions. When one end of the screen is deflected downward, the pull rope 42 pulls the second protrusion 44 on the corresponding side, causing the movable baffle 31 to flip outward around the first connecting rod 412, opening the discharge port 3 at the corresponding position, and discharging impurities or coarse particles that cannot pass through the screen holes on the screen. When the drive motor 51 reverses, the screen is deflected in the opposite direction, and the torsion spring 414 drives the movable baffle 31 to quickly reset and close the discharge port 3. This cycle is repeated to achieve continuous grading screening and automatic discharge of impurities.

[0055] S3. When the same end of the first screen 6 and the second screen 7 approaches each other, the anti-clogging top component 8 at the upper end of the second screen 7 rises synchronously, and the top rod 82 presses against the lower end face of the first screen 6, causing the first screen 6 to vibrate slightly, effectively reducing the probability of screen hole clogging and ensuring screening efficiency.

[0056] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. An apparatus for preparing magnesium oxide nanoparticles, comprising a sieving chamber (1), characterized in that, The screening chamber (1) is equipped with two screens that can rotate around a horizontal axis, arranged vertically at intervals. Each side wall of the screening chamber (1) has two discharge ports (3) corresponding to the two screens, one above the other. Each discharge port (3) has a movable baffle (31) movably embedded within it. The chamber also includes: Follow-up opening and closing assembly (4), the follow-up opening and closing assembly (4) includes a hinge (41) and a follow-up transmission component. The upper end of the movable baffle (31) is hinged to the side wall of the screening chamber (1) through the hinge (41). The two ends of the follow-up transmission component are respectively connected to the movable baffle (31) and the screen component. When one end of the screen component deflects downward, the follow-up transmission component synchronously drives the movable baffle (31) on the corresponding side to open. Synchronous drive (5) is connected to both screens and is used to drive the same end of the two screens to rotate synchronously in opposite directions so as to achieve alternating tilting and screening of the screens.

2. The apparatus for preparing magnesium oxide nanoparticles according to claim 1, characterized in that: The two screens are a first screen (6) and a second screen (7), with the first screen (6) located above the second screen (7) and the aperture of the first screen (6) being larger than that of the second screen (7).

3. The apparatus for preparing magnesium oxide nanoparticles according to claim 2, characterized in that: The hinge (41) includes a protrusion (411) fixed to the side wall of the screening chamber (1), a first connecting rod (412) is fixedly connected between two adjacent protrusions (411), a sleeve (413) is rotatably sleeved on the outside of the first connecting rod (412), and a connecting plate (415) is connected between the outer wall of the sleeve (413) and the movable baffle (31).

4. The apparatus for preparing magnesium oxide nanoparticles according to claim 3, characterized in that: The first connecting rod (412) is also provided with a torsion spring (414) on its outside. One end of the torsion spring (414) abuts against the protrusion (411), and the other end abuts against the sleeve (413).

5. The apparatus for preparing magnesium oxide nanoparticles according to claim 3, characterized in that: The follower transmission component includes: The first protrusion (43) is fixed to the outer wall of the screening chamber (1), and the end of the first protrusion (43) is provided with a guide rod; The second protrusion (44) is fixed to the lower end of the outer wall of the movable baffle (31). A pull rope (42) is connected between the second protrusion (44) and the frame of the screen. The pull rope (42) is arranged to pass around the guide rod.

6. The apparatus for preparing magnesium oxide nanoparticles according to claim 5, characterized in that: The pull rope (42) has a vertical clearance groove (45) at the side wall of the screening chamber (1).

7. The apparatus for preparing magnesium oxide nanoparticles according to claim 2, characterized in that: The synchronous drive component (5) includes a drive motor (51) and a second connecting rod (52). A second connecting rod (52) is connected to the middle of the side of the first screen (6) and the second screen (7). The output end of the drive motor (51) is installed at the end of one of the second connecting rods (52). Gears (53) are installed on the outside of the second connecting rods (52). A rack (55) meshes between the two gears (53) to realize the opposite synchronous rotation of the two second connecting rods (52).

8. The apparatus for preparing magnesium oxide nanoparticles according to claim 7, characterized in that: The synchronous drive component (5) also includes a guide frame (54) fixed to the outer wall of the screening chamber (1), and the rack (55) is slidably inserted through the guide frame (54).

9. The apparatus for preparing magnesium oxide nanoparticles according to claim 2, characterized in that: It also includes an upper top assembly (8), which is symmetrically installed on both sides of the upper end face of the second screen (7). Each side of the upper top assembly (8) includes multiple top rods spaced apart along the length direction of the second screen (7). From the end to the middle of the second screen (7), the height of each top rod increases in a gradient. Each top rod includes a connecting strip (81), and multiple top rods (82) are fixed at equal intervals along the length direction of the upper end face of the connecting strip (81).

10. A method for preparing magnesium oxide nanoparticles, using the apparatus for preparing magnesium oxide nanoparticles as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. The magnesium oxide nanoparticle raw material to be graded and screened is fed into the top feed port of the screening chamber (1). The raw material first falls onto the upper surface of the first screen (6) located above. After preliminary screening by the first screen (6), the particles that meet the pore size requirements fall onto the second screen (7) below for secondary fine screening. S2. During the screening process, the drive motor (51) is periodically started and its forward and reverse rotation is controlled. The output end of the drive motor (51) drives one of the second connecting rods (52) to rotate. Through the meshing transmission of the gear (53) and the rack (55), the other second connecting rod (52) is driven to rotate synchronously in the opposite direction, thereby driving the same end of the first screen (6) and the second screen (7) to deflect downward in opposite directions. When one end of the screen is deflected downward, the second protrusion (44) on the corresponding side is pulled by the pull rope (42), which drives the movable baffle (31) to flip outward around the first connecting rod (412), opening the discharge port (3) at the corresponding position, and discharging the impurities or coarse particles that cannot pass through the screen holes on the screen. When the drive motor (51) reverses, the screen is deflected in the opposite direction, and the torsion spring (414) drives the movable baffle (31) to quickly reset and close the discharge port (3). This cycle is repeated to achieve continuous grading screening and automatic discharge of impurities. S3. When the same end of the first screen (6) and the second screen (7) approaches each other, the anti-clogging top component (8) at the upper end of the second screen (7) rises synchronously, and the top rod (82) presses against the lower end face of the first screen (6), causing the first screen (6) to vibrate slightly, effectively reducing the probability of screen hole blockage and ensuring screening efficiency.

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