Air flow grading device for nanoscale aluminum hydroxide micro powder
By utilizing a nano-level aluminum hydroxide micro-powder airflow classifier, which combines a carrier gas inlet, a classifier motor, and a make-up air valve, the problem of achieving nano-level precision in traditional mechanical classification is solved, thus realizing efficient nano-level classification and precise separation of fine materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2026-04-14
AI Technical Summary
Traditional mechanical classification methods are insufficient to meet the classification accuracy requirements of nano-sized aluminum hydroxide powder, and they are prone to forming secondary large particles, resulting in low classification efficiency.
A nano-level aluminum hydroxide micro powder airflow classifier is adopted. Through precise flow control and reliable sealing, nano-level screening is achieved by coordinating the carrier gas inlet, the classifier motor and the make-up air valve. A flow stabilizing ring is set on the classifier wheel to suppress turbulence and ensure effective separation of fine and coarse materials.
It achieves nanometer-level classification accuracy and efficiency, avoids powder leakage and airflow leakage, and ensures the reliability and accuracy of classification.
Smart Images
Figure CN224114566U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of aluminum hydroxide flame retardant production equipment, specifically a nano-scale aluminum hydroxide micro powder airflow classification device. Background Technology
[0002] Aluminum hydroxide micropowder, used as a flame retardant, catalyst carrier, and composite material additive, has its particle size distribution directly affecting its specific surface area, dispersibility, and functionality. However, during production, the particle size distribution is often wide, including some coarse particles larger than the standard range. It needs to be graded before packaging; micropowder within the specified size range enters the packaging process, while coarse particles are returned to the production process until they meet the standard range. Nanoscale aluminum hydroxide micropowder, due to its high surface energy, easily agglomerates through hydrogen bonds or van der Waals forces, forming secondary large particles. Traditional mechanical grading methods are insufficient to meet nanoscale precision requirements or have low grading efficiency. Therefore, a highly efficient grading equipment is urgently needed. Utility Model Content
[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a nano-scale aluminum hydroxide micro powder airflow classification device, which can effectively improve the classification accuracy and achieve nano-scale screening through precise flow control and reliable sealing.
[0004] To address the problems of existing technologies, this utility model discloses an airflow classification device for nano-sized aluminum hydroxide powder, including a classification chamber. A classification wheel is installed in the classification chamber and is driven to rotate by a classification motor. A carrier gas inlet and a fine material outlet are provided on the side wall of the classification chamber. The horizontal position of the carrier gas inlet corresponds to the classification wheel and is located below the middle of the classification wheel. The horizontal position of the fine material outlet corresponds to the position above the top of the classification wheel.
[0005] A sidewall seal is provided between the top surface of the classifying wheel and the sidewall of the classifying chamber. A ring-shaped array of make-up air valves is provided at the hopper-shaped position of the classifying chamber. A coarse material outlet is connected to the bottom of the classifying chamber. The fine material outlet is a negative pressure airflow suction. The carrier gas inlet is filled with material by high pressure airflow.
[0006] Preferably, a shaft seal is provided between the grading motor and the top wall of the grading chamber.
[0007] Preferably, the shaft seal is a packing seal.
[0008] Preferably, the shaft seal adopts a composite structure of mechanical seal and gas seal.
[0009] Preferably, an air-closing valve is installed between the grading chamber and the coarse material outlet.
[0010] Preferably, the sidewall seal adopts an air-sealed structure.
[0011] Preferably, the sidewall seal adopts a mechanical seal structure, a sealing ring is provided on the side of the top surface of the classifying wheel, and a sealing ring extending inward is provided on the top sidewall of the classifying chamber. A fixing groove is provided on the side of the sealing ring facing the classifying wheel, and the sealing ring on the classifying wheel rotates in the fixing groove on the sealing ring.
[0012] Preferably, the horizontal position of the carrier gas inlet corresponds to the height of the lower part of the classifier wheel.
[0013] Preferably, the fine material outlet is located directly above the classifying wheel, and its height is higher than that of the classifying wheel.
[0014] Preferably, a flow stabilizing ring is also provided above the grading wheel. The flow stabilizing ring has a Venturi contraction structure, including a contraction section, a throat, and a diffusion section. The height of the flow stabilizing ring is lower than the fine material outlet.
[0015] Preferably, the bottom of the grading wheel has a sealed structure.
[0016] The beneficial effects of this invention are as follows: The device is reliably sealed and can achieve precise flow control to ultimately achieve nanoscale screening. Specifically, it includes: 1. By adjusting the airflow speed at the carrier gas inlet, the rotation speed of the classifying motor, and the opening of the make-up air valve, the classification requirements for different particle sizes are met. Fine particles enter the classifying wheel through the gaps between the blades and enter the stabilizing ring from the top of the classifying wheel. They are then drawn into the packaging process from the fine particle outlet. Coarse particles are thrown onto the side wall of the classification chamber under centrifugal force and gradually fall into the coarse particle outlet at the bottom of the classification chamber, returning to the production process. 2. A stabilizing ring is set above the classifying wheel. The stabilizing ring adopts a Venturi contraction structure, which can effectively guide the airflow of the classifying wheel to carry the fine particles into the upper part of the classification chamber, effectively suppress turbulence, establish a laminar flow field, and avoid the mixing of fine particles with coarse particles. 3. Sealing structures are installed between the classifier wheel shaft and the top wall of the classifier chamber, and between the top side of the classifier wheel and the side wall of the classifier chamber. An air-closing valve is installed at the coarse material outlet to effectively prevent powder leakage and airflow leakage. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of this utility model;
[0018] Figure 2 This is a top view of the grader wheel in this utility model;
[0019] Figure 3 yes Figure 1 Enlarged structural diagram at point A;
[0020] Figure 4 This is a structural schematic diagram of Embodiment 2;
[0021] Figure 5 This is a schematic diagram of the current stabilizing ring in Example 2.
[0022] Figure label:
[0023] 1. Grading chamber; 2. Grading wheel; 3. Grading motor; 4. Carrier gas inlet; 5. Fine material outlet; 6. Side wall seal; 7. Make-up air valve; 8. Coarse material outlet; 9. Shaft seal; 10. Air shut-off valve; 11. Sealing ring; 12. Sealing ring; 13. Fixing groove; 14. Flow stabilizing ring; 15. Contraction section; 16. Throat; 17. Diffusion section. Detailed Implementation
[0024] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the structure of the present invention more clearly.
[0025] In an air classifier, particles are subjected to both inward airflow drag and outward centrifugal force in the horizontal direction. The airflow drag is provided by the negative pressure suction device at the fine material outlet, while the centrifugal force is provided by the vortex generated by the continuous rotation of the classifying wheel. The relative magnitudes of these two forces can be adjusted by regulating the airflow velocity at the carrier gas inlet, the speed of the classifying motor, and whether the make-up air valve is open. When the centrifugal force on coarse particles is greater than the airflow drag, they are eventually thrown against the side wall of the classification chamber and fall to the coarse material outlet under gravity. Conversely, when the centrifugal force on fine particles is less than the airflow drag, they are adsorbed into the classifying wheel and eventually drawn to the fine material outlet.
[0026] Example 1: As per the attached instruction manual Figure 1-3 As shown, an airflow classification device for nano-sized aluminum hydroxide powder includes a classification chamber 1, within which a classification wheel 2 is installed. The classification wheel 2 is driven to rotate by a classification motor 3. A carrier gas inlet 4 and a fine material outlet 5 are located on the side wall of the classification chamber 1. The horizontal position of the carrier gas inlet 4 corresponds to the classification wheel 2, specifically below the middle of the classification wheel 2. The horizontal position of the fine material outlet 5 corresponds to the position above the top of the classification wheel 2. A side wall seal 6 is installed between the top surface of the classification wheel 2 and the side wall of the classification chamber 1. A ring-shaped array of make-up air valves 7 is installed at the bucket-shaped position of the classification chamber 1. A coarse material outlet 8 is connected to the bottom of the classification chamber 1. The fine material outlet 5 is supplied by negative pressure airflow suction, and the carrier gas inlet 4 is supplied with material by high-pressure airflow.
[0027] The horizontal position of the carrier gas inlet 4 corresponds to the lower part of the classifier wheel 2. The fine material outlet 5 is located directly above the classifier wheel 2 and is higher than the classifier wheel 2. The bottom of the classifier wheel 2 is a sealed structure.
[0028] A shaft seal 9 is provided between the grading motor 3 and the top wall of the grading chamber 1. The shaft seal 9 adopts a packing seal and a composite structure of mechanical seal and gas seal.
[0029] An air-closing valve 10 is installed between the classification chamber 1 and the coarse material outlet 8.
[0030] The side wall seal 6 can be an air seal structure or a mechanical seal structure. Specifically, a sealing ring 11 is provided on the side of the top surface of the classifying wheel 2, and a sealing ring 12 extending inward is provided on the top side wall of the classifying chamber. A fixing groove 13 is provided on the side of the sealing ring 12 facing the classifying wheel 2, and the sealing ring 11 on the classifying wheel 2 rotates in the fixing groove 13 on the sealing ring 12.
[0031] In this embodiment, a high-pressure airflow carries the powder into the classification chamber 1 through the carrier gas inlet 4. Within the classification chamber 1, a negative pressure suction system is set at the fine material outlet 5. A sidewall seal 6 or a mechanical seal structure consisting of a sealing ring 11 and a sealing ring 12 is installed between the top surface of the classifying wheel 2 and the side wall of the classification chamber 1. This ensures that the fine material can only enter unidirectionally through the gaps between the blades of the classifying wheel 2, and will not diffuse into the classification chamber 1 at the top of the classifying wheel 2 through the gap between the classifying wheel 2 and the classification chamber 1. Simultaneously, the classification motor 3 drives the classifying wheel 2 to rotate continuously, generating vortices. The powder follows the rotation under the influence of these vortices and, driven by centrifugal force, continuously moves towards the side wall of the classification chamber 1. The fine material is drawn into the classifier wheel 2 by the airflow drag force that is greater than the centrifugal force it experiences, and leaves from the top of the classifier wheel 2. Under the negative pressure of the fine material outlet 5, it enters the fine material outlet 5. The coarse material is thrown onto the side wall of the classifier chamber 1 by the airflow drag force that is less than the centrifugal force it experiences, and then falls to the coarse material outlet 8 under the action of gravity.
[0032] The horizontal position of the carrier gas inlet 4 corresponds to the classifier wheel 2, and its horizontal position corresponds to the height below the middle of the classifier wheel 2. The horizontal position of the fine material outlet 5 corresponds to the position above the top of the classifier wheel 2. Thus, after the powder enters, it is directly driven by the classifier wheel 2 and easily enters the interior of the classifier wheel 2. The fine material outlet 5, being located above the top of the classifier wheel 2, ensures the extraction of the powder.
[0033] A ring-shaped array of make-up air valves 7 is installed at the hopper-shaped position of the grading chamber 1. These valves can introduce external air to compensate for the system's airflow, ensuring airflow stability, thereby controlling airflow speed and optimizing grading accuracy. To further improve grading accuracy, automatic make-up air valves 7 can also be used, with the number of open make-up air valves 7 adjusted in real time by a PLC based on feedback from a pressure sensor.
[0034] An air-closing valve 10 is installed between the classification chamber 1 and the coarse material outlet 8. On the one hand, it prevents the intake of external air and the leakage of internal air through the mechanical seal of the rotating valve plate, thereby achieving a seal at the coarse material outlet 8 and ensuring a negative pressure state in the classification chamber 1. On the other hand, it also continuously and quantitatively discharges the coarse material, preventing material accumulation or blockage of the pipeline. It can also prevent the airflow from carrying the separated coarse powder back into the classification zone, ensuring classification accuracy.
[0035] In this invention, the top of the grading wheel 2 is open and the bottom is sealed. Obviously, depending on the setting of parameters such as airflow, the bottom of the grading wheel 2 can also be designed as a semi-closed structure.
[0036] Example 2: Figure 4 As shown, a flow stabilizing ring 14 is also provided above the classifier wheel 2. The flow stabilizing ring 14 has a Venturi contraction structure, including a contraction section 15, a throat 16, and a diffuser section 17. The height of the flow stabilizing ring 14 is lower than the fine material outlet 5. According to the Venturi effect, when fluid flows through a narrow section of a pipe, i.e. Figure 4 At the throat 16, the flow rate increases and the pressure decreases. As the pipe gradually expands, the flow rate gradually decreases and the pressure increases. This ensures both rapid suction of fine materials and stable flow in the classification chamber 1 at the top of the classification wheel 2, thereby improving the suction efficiency of fine materials.
[0037] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.
Claims
1. A nano-scale aluminum hydroxide micropowder airflow classification device, comprising a classification chamber, wherein a classification wheel is disposed within the classification chamber, and the classification wheel is driven to rotate by a classification motor, characterized in that: The side wall of the classification chamber is provided with a carrier gas inlet and a fine material outlet. The horizontal position of the carrier gas inlet corresponds to the classification wheel, and its horizontal position corresponds to the height below the middle of the classification wheel. The horizontal position of the fine material outlet corresponds to the height above the top of the classification wheel. A sidewall seal is provided between the top surface of the classifying wheel and the sidewall of the classifying chamber. A ring-shaped array of make-up air valves is provided at the bucket-shaped position of the classifying chamber. A coarse material outlet is connected to the bottom of the classifying chamber. The fine material outlet is a negative pressure airflow suction. The carrier gas inlet is filled with material by high pressure airflow.
2. The airflow classification device for nano-sized aluminum hydroxide powder according to claim 1, characterized in that: A shaft seal is provided between the grading motor and the top wall of the grading chamber.
3. The airflow classification device for nano-sized aluminum hydroxide powder according to claim 2, characterized in that: The shaft seal is a packing seal.
4. The airflow classification device for nano-sized aluminum hydroxide powder according to claim 2, characterized in that: An air-closing valve is installed between the grading chamber and the coarse material outlet.
5. The airflow classification device for nano-sized aluminum hydroxide powder according to claim 1, characterized in that: The sidewall seal adopts an air-sealed structure.
6. The airflow classification device for nano-sized aluminum hydroxide powder according to claim 1, characterized in that: The sidewall seal adopts a mechanical seal structure. A sealing ring is provided on the side of the top surface of the classifying wheel, and a sealing ring extending inward is provided on the top sidewall of the classifying chamber. A fixing groove is provided on the side of the sealing ring facing the classifying wheel, and the sealing ring on the classifying wheel rotates in the fixing groove on the sealing ring.
7. The airflow classification device for nano-sized aluminum hydroxide powder according to claim 1, characterized in that: The horizontal position of the carrier gas inlet corresponds to the height of the lower part of the classifier wheel.
8. The airflow classification device for nano-sized aluminum hydroxide powder according to claim 1, characterized in that: The fine material outlet is located directly above the classifying wheel, and its height is higher than that of the classifying wheel.
9. The airflow classification device for nano-sized aluminum hydroxide powder according to claim 1, characterized in that: A flow stabilizing ring is also provided above the classifier wheel. The flow stabilizing ring has a Venturi contraction structure, including a contraction section, a throat, and a diffusion section. The height of the flow stabilizing ring is lower than the fine material outlet.
10. The airflow classification device for nano-sized aluminum hydroxide powder according to claim 1, characterized in that: The bottom of the grading wheel has a sealed structure.