Photocatalytic material preparation device

Abstract

The application belongs to the technical field of gas deposition coating, and particularly relates to a photocatalytic material preparation device. The following scheme is provided, which comprises a heating tank, a reaction tank and a plurality of substrates arranged in the reaction tank. The end of the reaction tank is provided with a rotating plate capable of reciprocating deflection. The plurality of substrates are installed on the rotating plate. One end of the rotating plate is drivingly connected with a driving motor. The bottom of the reaction tank is provided with a reaction gas pipe between adjacent two substrates. A swing mechanism is arranged below the adjacent two substrates. One end of the swing mechanism is connected with a limiting assembly. The swing mechanism is freely movable in the horizontal direction along the limiting assembly. The application further comprises a pressure detection module, a temperature detection module and an airflow detection module. The application comprehensively controls and adjusts the rotating speed of the driving motor through pressure detection, temperature detection and airflow detection, so as to ensure the uniformity of film generation and improve the intelligentization, integration and high performance of coating operation.

Description

Technical Field

[0001] The invention relates to the technical field of vapor deposition coatings, in particular to a device for preparing photocatalytic materials. Background Art

[0002] Coating of photocatalytic materials based on chemical vapor deposition (CVD) is an important material preparation technology.

[0003] Referring to the Chinese patent with patent publication number CN102953049B, a chemical vapor deposition coating device is disclosed, and the technical solution adopted is: it includes a reactor, there is no support tube in the reactor, an exhaust cap is provided at the upper end of the support tube, an exhaust gas channel is between the reactor and the support tube, and the support tube is divided into a deposition area, a gas distribution area and a preheating area from top to bottom.

[0004] In existing processes, a precursor is generally heated to its evaporation temperature to form a gas, which is then transported to a reaction chamber via a carrier gas. In the reaction chamber, the precursor and the reaction gas undergo a chemical reaction to form a solid film on the surface of the substrate. However, in the actual coating process for flat substrates, the thickness difference caused by the direction of airflow movement will affect the film preparation effect. Summary of the Invention

[0005] Based on the technical problems of the background technology, the present invention proposes a device for preparing photocatalytic materials.

[0006] A photocatalytic material preparation device proposed in the present invention includes a heating tank, a reaction tank, and multiple substrates arranged in the reaction tank. The end of the reaction tank is provided with a reciprocating rotating plate, and the multiple substrates are mounted on the rotating plate. One end of the rotating plate is connected to a drive motor. A reaction gas pipe is provided at the bottom of the reaction tank between two adjacent substrates. A swing mechanism is provided below the two adjacent substrates. One end of the swing mechanism is connected to a limit assembly, and the swing mechanism moves freely in the horizontal direction along the limit assembly. A central processing unit is provided outside the reaction tank. The device also includes: a pressure detection module, provided on the limit assembly, for detecting the impact force of the swing mechanism toward one end and generating a pressure deviation coefficient through the central processing unit; a temperature detection module, provided on the rotating plate, for detecting the ambient temperature of the substrate and generating a temperature variation coefficient through the central processing unit; and an airflow detection module, provided at the top of the substrate, for detecting the airflow intensity at the top of the substrate and generating an airflow fluctuation coefficient through the central processing unit. The central processing unit performs a comprehensive analysis of the pressure deviation coefficient, the temperature variation coefficient, and the airflow fluctuation coefficient to calculate a speed control coefficient. The speed control coefficient is compared with a preset value to control and adjust the reciprocating speed of the drive motor.

[0007] Preferably, the limiting component is provided with a limiting frame, a slide groove is provided in the limiting frame, both ends of the slide groove are penetrated, and limiting grooves are provided on the top and bottom of the slide groove.

[0008] Preferably, the swing mechanism is provided with a movable rod, the outer wall of one end of the movable rod is in sliding contact with the inner wall of the slide groove, the top and bottom of the movable rod are fixed with limit blocks that are in sliding contact with the inner wall of the limit groove, and a plurality of vertically extending swing leaves are fixed on the movable rod.

[0009] Preferably, a top frame is installed at the end of the rotating plate located above the substrate, a bottom frame is installed at the end of the rotating plate located below the substrate, and the substrate is installed between the top frame and the bottom frame.

[0010] Preferably, a tank door is provided at a position at the end of the reaction tank corresponding to the rotating plate, and a stop bar is installed at a position of the tank door facing the substrate.

[0011] Preferably, the pressure detection module is provided with pressure sensors installed at both ends of the limit frame, one end of the pressure sensor extends into the slide groove, and a pressure deviation coefficient is generated by the central processing unit; when the pressure deviation coefficient decreases, it means that the impact force decreases and the bottom airflow resistance increases, and the drive motor needs to be driven to slow down; when the pressure deviation coefficient increases, it means that the impact force increases and the bottom airflow resistance decreases, and the drive motor needs to be driven to speed up.

[0012] Preferably, the temperature detection module is provided with a plurality of temperature sensors installed on the rotating plate, and temperature sensors are vertically distributed on both sides of the substrate, and a temperature variation coefficient is generated by the central processing unit; when the temperature variation coefficient decreases, it means that the temperature difference above is small, that is, the vertical upward flow rate of the bottom airflow is high, and the motor needs to be driven to increase the speed; when the temperature variation coefficient increases, it means that the temperature difference above is large, that is, the vertical upward flow rate of the bottom airflow is low, and the motor needs to be driven to decelerate.

[0013] Preferably, the airflow detection module is provided with a plurality of airflow intensity detectors installed on both sides of the top frame, and generates an airflow fluctuation coefficient through the central processing unit; when the airflow fluctuation coefficient decreases, it means that the top airflow intensity decreases, and the drive motor needs to be decelerated; when the airflow fluctuation coefficient increases, it means that the top airflow intensity increases, and the drive motor needs to be increased.

[0014] Preferably, the lower limit threshold and the upper limit threshold of the speed control coefficient are set in advance, and the speed of the drive motor is controlled and adjusted by comparing the calculated speed control coefficient with the lower limit threshold and the upper limit threshold; when the speed control coefficient is less than the lower limit threshold, the deceleration operation of the drive motor is executed; when the speed control coefficient is greater than the upper limit threshold, the speed increase operation of the drive motor is executed.

[0015] The beneficial effects of the present invention are:

[0016] 1. In the present invention, the dispersion effect of the bottom airflow is improved by the reciprocating deflection of the substrate along with the rotating plate and the movement of the swing mechanism relative to the substrate, thereby making the reaction dispersion between the reaction gas and the precursor uniform, thereby improving the uniformity of the thin film generated on the surface of the substrate. The central processing unit comprehensively analyzes the pressure deviation coefficient generated by the swing mechanism, the temperature variation coefficient around the substrate, and the airflow fluctuation coefficient at the top of the substrate to generate a speed control coefficient, thereby comprehensively controlling and adjusting the reciprocating rotation speed of the drive motor to ensure the uniformity of the thin film generation and improve the intelligence, integration and high performance of the coating operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the overall structure of a photocatalytic material preparation device proposed in the present invention;

[0018] Figure 2 This is a schematic diagram of the reaction tank structure of a photocatalytic material preparation device proposed in the present invention;

[0019] Figure 3 This is a schematic diagram of the internal structure of a reaction tank of a photocatalytic material preparation device proposed in the present invention;

[0020] Figure 4 This is a schematic diagram of the rotating plate structure of a photocatalytic material preparation device proposed by the present invention;

[0021] Figure 5 This is a schematic structural diagram of a limiting component and a swing mechanism of a photocatalytic material preparation device proposed in the present invention;

[0022] Figure 6 This is a schematic structural diagram of a limiting component of a photocatalytic material preparation device proposed in the present invention.

[0023] In the figure: 1 heating tank, 101 carrier gas pipe, 102 gas outlet pipe, 2 reaction tank, 201 gas inlet pipe, 202 reaction gas pipe, 203 exhaust pipe, 204 tank door, 3 substrate, 4 heating element, 5 rotating plate, 501 top frame, 502 bottom frame, 6 rotating shaft, 7 driving motor, 8 limit assembly, 801 limit frame, 802 limit slot, 9 swing mechanism, 901 movable rod, 902 swing leaf, 903 limit block, 904 limit plate, 10 temperature sensor, 11 airflow intensity detector, 12 pressure sensor. DETAILED DESCRIPTION

[0024] Example 1: Reference Figures 1-6, a photocatalytic material preparation device, comprising a heating tank 1, a reaction tank 2 and a plurality of plate-shaped substrates 3 arranged in the reaction tank 2, a gaseous precursor generated in the heating tank 1 is sent into the reaction tank 2, the heating tank 1 is filled with the precursor and is provided with a heating unit to vaporize the precursor, a carrier gas pipe 101 is connected to the bottom of one side of the heating tank 1 for sending out the vaporized precursor, an outlet pipe 102 is connected to the top of the heating tank 1, an inlet pipe 201 is connected to the bottom of one end of the reaction tank 2, the inlet pipe 201 and the outlet pipe 102 are connected, the top of the reaction tank 2 is connected to the exhaust pipe 203, the carrier gas pipe 101, the outlet pipe 102, the inlet pipe 201 and the exhaust pipe 203 are all provided with electric control valves, a reciprocatingly deflectable rotating plate 5 is provided at the end of the reaction tank 2, and a plurality of substrates 3 are installed on the rotating plate 5, one end of the rotating plate 5 away from the substrate 3 is transmission-connected to the driving motor 7, a rotating shaft 6 is installed between the output shaft of the driving motor 7 and the rotating plate 5, and the rotating shaft 6 is rotatably arranged on the shell of the reaction tank 2, and a reaction gas pipe 202 is provided at the bottom of the reaction tank 2 between two adjacent substrates 3. The reaction gas pipe 202 introduces reaction gas into the reaction tank 2, and an electric control valve is provided on the reaction gas pipe 202. A heating element 4 is installed below the reaction tank 2, and the heating element 4 is arranged below the substrate 3 and distributed on both sides of the rotating plate 5. A swing mechanism 9 is provided below between the two adjacent substrates 3, and one end of the swing mechanism 9 is connected to a limiting component 8. The limiting component 8 is fixedly installed on the inner wall of the reaction tank 2, and the swing mechanism 9 is free to move in the horizontal direction along the limiting component 8. A central processing unit is provided outside the reaction tank 2;

[0025] Also included are:

[0026] The pressure detection module is provided on the limit assembly 8 and is used to obtain the impact force of the swing mechanism 9 moving toward one end of the limit assembly 8 and generate a pressure deviation coefficient through the central processing unit;

[0027] The temperature detection module is located above the center of the rotating plate 5 and is used to obtain the temperature of the two sides of the substrate 3 and generate a temperature variation coefficient through the central processing unit;

[0028] The airflow detection module is provided on both sides of the top of the substrate 3, and is used to obtain the airflow intensity on both sides of the top of the substrate 3 and generate the airflow fluctuation coefficient through the central processing unit;

[0029] The central processing unit performs a comprehensive analysis of the pressure deviation coefficient, the temperature variation coefficient and the airflow fluctuation coefficient to calculate the speed control coefficient. By comparing the speed control coefficient with a preset reference value, the reciprocating speed of the drive motor 7 is controlled and adjusted.

[0030] During operation, the heating tank 1 is filled with a precursor and then heated and vaporized in the heating tank 1. The carrier gas introduced through the carrier gas pipe 101 delivers the gaseous precursor along the outlet pipe 102 and the inlet pipe 201 to the bottom position of the reaction tank 2, and the reaction gas is introduced upward from the bottom of the reaction tank 2, so that the reaction gas and the precursor react to form a thin film on the surface of the substrate 3; during the generation process, the driving motor 7 drives the rotating plate 5 to deflect back and forth. Under normal conditions, the substrate is placed vertically, and the reaction gas pipe 202 is in the middle position of the adjacent substrate 3. As the substrate 3 is When the rotating plate 5 deflects to the maximum left and right angle, it will stay above the reaction gas pipe 202. During the deflection of the substrate 3, the bottom end of the substrate 3 will hit the swing mechanism 9. When the substrate 3 deflects to the maximum angle, the swing mechanism 9 will continue to slide forward and hit the pressure detection module at the end of the limit assembly 8. Therefore, the reciprocating deflection of the substrate 3 with the rotating plate 5 and the movement of the swing mechanism 9 relative to the substrate 3 improve the dispersion effect of the bottom airflow, thereby ensuring the uniformity of the reaction dispersion between the reaction gas and the precursor, thereby improving the uniformity of the thin film formation on the surface of the substrate 3.

[0031] At the same time, the impact force of the swing mechanism 9 is detected by the pressure detection module, and a pressure deviation coefficient is generated. When the substrate 3 swings too fast, the bottom airflow accumulates, which increases the bottom airflow resistance and reduces the impact force of the swing mechanism 9. That is, the pressure deviation coefficient is too small, indicating that the bottom airflow resistance is too large, and the rotation speed of the substrate 3 needs to be reduced to ensure the smoothness of the airflow. On the contrary, the pressure deviation coefficient is too large, indicating that the bottom airflow resistance is too small, and the rotation speed of the substrate 3 needs to be increased. The temperature change of the overall area position is detected by the temperature detection module, and the corresponding temperature change coefficient is calculated. When the temperature change coefficient is too high, it means that the temperature difference above is large, that is, the heat below is too high. The vertical upward flow rate of the airflow is too low, so the rotation speed of the substrate 3 needs to be reduced; the airflow intensity at the top position of the substrate 3 is detected by the airflow detection module, and the airflow fluctuation coefficient is generated. When the airflow fluctuation coefficient is too small, that is, the top airflow intensity is too low, the rotation speed of the substrate 3 needs to be reduced to increase the vertical upward airflow; the central processing unit comprehensively analyzes the pressure deviation coefficient, temperature variation coefficient and airflow fluctuation coefficient to generate a speed control coefficient, thereby comprehensively controlling and adjusting the reciprocating rotation speed of the drive motor 7 to ensure the uniformity of film generation and improve the intelligence, integration and high performance of the coating operation.

[0032] In the present invention, the limiting component 8 is provided with a limiting frame 801 installed with the inner wall of the reaction tank 2, a slide is provided in the limiting frame 801, the two ends of the slide are penetrated, and the top and bottom of the slide are provided with limiting grooves 802. The swing mechanism 9 is provided with a horizontally extending movable rod 901, the movable rod 901 is located below the substrate 3, and the outer wall of one end of the movable rod 901 is in sliding contact with the inner wall of the slide, and the top and bottom of the movable rod 901 are fixed with limiting blocks 903 in sliding contact with the inner wall of the limiting groove 802. The movable rod 901 is close to the limiting frame 801. A limiting plate 904 is installed at one end, and the limiting plate 904 is in sliding contact with the outer wall of the limiting frame 801 away from the substrate 3. A plurality of vertically extending swing leaves 902 are fixed on the movable rod 901, so that the movable rod 901 can slide horizontally along the slide groove through the limiting block 903 and the limiting plate 904. When the bottom end of the substrate 3 hits the swing leaf 902 and the substrate 3 stops deflecting, the movable rod 901 may slide forward with the swing leaf 902, so that the swing leaf 902 and the substrate 3 move relative to each other to disperse the airflow movement, so as to improve the coating effect.

[0033] In the present invention, a horizontally extending top frame 501 is installed at the end of the rotating plate 5 located above the substrate 3, and a horizontally extending bottom frame 502 is installed at the end of the rotating plate 5 located below the substrate 3. The substrate 3 is installed between the top frame 501 and the bottom frame 502. A tank door 204 is provided at the position of the end of the reaction tank 2 corresponding to the rotating plate 5. A resist is installed at the position of the tank door 204 facing the substrate 3. The substrate 3 can be placed or removed by opening the tank door 204, and when the tank door 204 is closed, the resist is brought into sliding contact with the end of the substrate 3 to prevent the substrate 3 from detaching and ensure the effectiveness of the substrate 3 rotating with the rotating plate 5.

[0034] In the present invention, the pressure detection module is provided with a pressure sensor 12 installed at both ends of the limit frame 801. One end of the pressure sensor 12 extends into the slide groove, and a pressure deviation coefficient is generated by the central processing unit; when the pressure deviation coefficient decreases, it means that the impact force decreases and the bottom airflow resistance increases, and the drive motor 7 needs to be decelerated to reduce the bottom airflow resistance; when the pressure deviation coefficient increases, it means that the impact force increases and the bottom airflow resistance decreases, and the drive motor 7 needs to be accelerated.

[0035] In the present invention, the temperature detection module is provided with a plurality of temperature sensors 10 mounted on the rotating plate 5, and the temperature sensors 10 are vertically distributed on both sides of the substrate 3, and the temperature variation coefficient is generated by the central processing unit; when the temperature variation coefficient decreases, it means that the temperature difference above is small, that is, the vertical upward flow rate of the bottom airflow is high, and the driving motor 7 needs to be increased; when the temperature variation coefficient increases, it means that the temperature difference above is large, that is, the vertical upward flow rate of the bottom airflow is low, and the driving motor 7 needs to be decelerated to speed up the vertical upward flow rate between adjacent substrates 3.

[0036] In the present invention, the airflow detection module is provided with a plurality of airflow intensity detectors 11 installed on both sides of the top frame 501. The airflow intensity detector 11 can optionally use a pressure differential flow sensor to generate an airflow fluctuation coefficient through the central processing unit; when the airflow fluctuation coefficient decreases, it means that the top airflow intensity decreases, and the drive motor 7 needs to be decelerated to increase the vertical upward airflow; when the airflow fluctuation coefficient increases, it means that the top airflow intensity increases, and the drive motor 7 needs to be increased.

[0037] In the present invention, the lower limit threshold and the upper limit threshold of the speed control coefficient are set in advance, and the speed of the drive motor 7 is controlled and adjusted by comparing the calculated speed control coefficient with the lower limit threshold and the upper limit threshold; when the speed control coefficient is less than the lower limit threshold, the deceleration operation of the drive motor 7 is executed; when the speed control coefficient is greater than the upper limit threshold, the speed increase operation of the drive motor 7 is executed.

[0038] Example 2: A device for preparing a photocatalytic material, based on Example 1:

[0039] Assume there are a total of The pressure values ​​detected by the pressure sensors 12 at both ends of each group of limit components 8 are recorded as and , ;

[0040] The calculation formula of pressure deviation coefficient is:

[0041]

[0042] in It is a predetermined ideal average pressure; the ideal average pressure is the average pressure applied to both ends of the limit assembly 8 when the system is in optimal working condition. This value can be determined by experimental testing, theoretical calculation or empirical value.

[0043] Example 3: A device for preparing a photocatalytic material, based on Example 1:

[0044] Assume that in the reaction environment A vertical array of temperature sensors 10, The temperature value measured by the sensor is recorded as , ; Generally speaking, sensors are numbered from bottom to top and from left to right;

[0045] Calculate the average temperature gradient: ;

[0046] Predetermine the ideal temperature gradient The ideal temperature gradient is the temperature gradient corresponding to the system being in optimal working condition and the vertical upward flow velocity of the bottom airflow being appropriate. This value can be determined through multiple experimental measurements and combined with process requirements, and is a reference standard.

[0047] Calculate the temperature coefficient of variation: .

[0048] Example 4: A device for preparing a photocatalytic material, based on Example 1:

[0049] Assume that there are a total of The air flow intensity detectors 11 are arranged in a horizontal array. The flow rate value measured by the air flow intensity detector 11 is recorded as , ;

[0050] Calculate the average flow rate: ;

[0051] The standard deviation of the flow rate reflects the degree of dispersion of the measured values ​​of each airflow intensity detector 11 relative to the average value, and the calculation formula is: ;

[0052] Determine the ideal standard deviation in advance The ideal standard deviation is the flow standard deviation corresponding to when the system is in optimal working condition and the top airflow intensity is appropriate and evenly distributed. It can be obtained by taking the average value of multiple experimental measurements or based on theoretical analysis.

[0053] Calculate the airflow fluctuation coefficient: .

[0054] Example 5: A device for preparing a photocatalytic material, based on the above examples:

[0055] The weighted average method is used to synthesize the pressure deviation coefficient , Temperature variation coefficient and airflow fluctuation coefficient Calculate the speed control coefficient ;set up 、 、 are the weights of pressure deviation coefficient, temperature variation coefficient and airflow fluctuation coefficient respectively, and , then the calculation formula of the speed control coefficient is:

[0056] .

[0057] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A device for preparing a photocatalytic material, comprising a heating tank (1), a reaction tank (2), and a plurality of substrates (3) arranged in the reaction tank (2), characterized in that: The end of the reaction tank (2) is provided with a rotating plate (5) that can be reciprocated and deflected, and a plurality of substrates (3) are mounted on the rotating plate (5). One end of the rotating plate (5) is connected to a driving motor (7). A reaction gas pipe (202) is provided at the bottom of the reaction tank (2) between two adjacent substrates (3). A swing mechanism (9) is provided below between the two adjacent substrates (3). One end of the swing mechanism (9) is connected to a limiting assembly (8). The swing mechanism (9) moves freely in the horizontal direction along the limiting assembly (8). A central processing unit is provided outside the reaction tank (2); Also included are: A pressure detection module is provided on the limit assembly (8) and is used to obtain the impact force of the swing mechanism (9) toward one end and generate a pressure deviation coefficient through a central processing unit; A temperature detection module is provided on the rotating plate (5) and is used to obtain the ambient temperature of the substrate (3) and generate a temperature variation coefficient through a central processing unit; An airflow detection module is provided at the top of the substrate (3) and is used to obtain the airflow intensity at the top of the substrate (3) and generate an airflow fluctuation coefficient through a central processing unit; The central processing unit performs a comprehensive analysis of the pressure deviation coefficient, the temperature variation coefficient and the air flow fluctuation coefficient to calculate the speed control coefficient. The speed control coefficient is compared with a preset value to control and adjust the reciprocating speed of the drive motor (7).

2. The device for preparing a photocatalytic material according to claim 1, characterized in that: The limiting assembly (8) is provided with a limiting frame (801), a slide groove is provided in the limiting frame (801), both ends of the slide groove are penetrated, and the top and bottom of the slide groove are provided with limiting grooves (802).

3. The device for preparing a photocatalytic material according to claim 2, characterized in that: The swing mechanism (9) is provided with a movable rod (901), the outer wall of one end of the movable rod (901) is in sliding contact with the inner wall of the slide groove, and the top and bottom of the movable rod (901) are fixed with limit blocks (903) in sliding contact with the inner wall of the limit groove (802), and a plurality of vertically extending swing leaves (902) are fixed on the movable rod (901).

4. A device for preparing a photocatalytic material according to any one of claims 1 to 3, characterized in that: The end of the rotating plate (5) is located above the substrate (3) and is installed with a top frame (501); the end of the rotating plate (5) is located below the substrate (3) and is installed with a bottom frame (502); the substrate (3) is installed between the top frame (501) and the bottom frame (502).

5. The device for preparing a photocatalytic material according to claim 4, characterized in that: A tank door (204) is provided at a position of the end of the reaction tank (2) corresponding to the rotating plate (5), and a stop bar is installed at a position of the tank door (204) facing the substrate (3).

6. The device for preparing a photocatalytic material according to claim 3, characterized in that: The pressure detection module is provided with a pressure sensor (12) installed at both ends of the limit frame (801), one end of the pressure sensor (12) extends into the slide groove, and a pressure deviation coefficient is generated by the central processing unit; When the pressure deviation coefficient decreases, it means that the impact force decreases and the bottom airflow resistance increases, and the drive motor (7) needs to be decelerated; When the pressure deviation coefficient increases, it means that the impact force increases and the bottom air flow resistance decreases, and the driving motor (7) needs to be increased.

7. The device for preparing a photocatalytic material according to claim 3, characterized in that: The temperature detection module is provided with a plurality of temperature sensors (10) mounted on the rotating plate (5), and temperature sensors (10) are vertically distributed on both sides of the substrate (3), and a temperature variation coefficient is generated by a central processing unit; When the temperature variation coefficient decreases, it means that the temperature difference at the top is small, that is, the vertical upward flow velocity of the bottom airflow is high, and the motor (7) needs to be driven to increase the speed; When the temperature variation coefficient increases, it means that the temperature difference at the top is large, that is, the vertical upward flow velocity of the bottom airflow is low, and the drive motor (7) needs to be decelerated.

8. The device for preparing a photocatalytic material according to claim 3, characterized in that: The airflow detection module is provided with a plurality of airflow intensity detectors (11) installed on both sides of the top frame (501), and generates an airflow fluctuation coefficient through a central processing unit; When the airflow fluctuation coefficient decreases, it means that the top airflow intensity decreases, and the drive motor (7) needs to be decelerated; When the airflow fluctuation coefficient increases, it means that the top airflow intensity increases, and the driving motor (7) needs to increase the speed.

9. A device for preparing a photocatalytic material according to any one of claims 1 to 3, characterized in that: Presetting a lower threshold and an upper threshold of a speed control coefficient, and comparing the calculated speed control coefficient with the lower threshold and the upper threshold to control and adjust the speed of the drive motor (7); When the speed control coefficient is less than the lower limit threshold, a deceleration operation of the drive motor (7) is executed; When the speed control coefficient is greater than the upper limit threshold, the speed increasing operation of the drive motor (7) is executed.

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