Sinusoidal wall-surface annular photocatalytic reactor and application thereof in degradation of gaseous pollutants

Abstract

The invention discloses a sine-type wall surface annular photocatalytic reactor and application thereof in degradation of gaseous pollutants, the sine-type wall surface annular photocatalytic reactor comprises a reactor main body, a light source is arranged on the central axis of the reactor main body, the inner side wall of the reactor main body is a sine-type wall surface, and a photocatalyst layer is arranged on the inner side wall. One end of the reactor main body is provided with an air inlet, and the other end is provided with an air outlet. The airflow directly impacts the wall surface of the air inlet, so that damage to the lamp source caused by direct impact of the airflow is avoided; the sinusoidal wall surface is used as a carrier of a photocatalyst, and the amplitude A and the angular frequency omega are adjusted, so that the photocatalytic reactor has larger reaction area and low pressure drop, the collision between pollutants and active sites of the photocatalyst is increased, and meanwhile, the fluid viscosity is adjusted, so that an internal flow field of the photocatalytic reactor is more stable. Compared with an annular photocatalytic device with a smooth wall surface, the trichloroethylene degradation efficiency of the annular photocatalytic device with the sinusoidal wall surface is improved by 5.13%.

Description

Technical Field

[0001] The invention belongs to the technical field of photocatalytic reactors and pollutant degradation, and in particular relates to a sinusoidal wall-surface annular photocatalytic reactor and application thereof in degrading gaseous pollutants. Background Art

[0002] Trichloroethylene is a colorless, transparent and volatile liquid, which is a typical volatile organic pollutant (VOCs). Trichloroethylene is widely used as a solvent to clean metals and chemical synthesis; in life, it is also used as a refrigerant, dry cleaning agent for clothing, bactericide, printing ink adhesive, detergent, cleaning liquid for cosmetics, etc. In addition, trichloroethylene is also a solvent of toxicity level, a Class I human carcinogen, with carcinogenic, teratogenic and reproductive toxic effects. Photocatalytic oxidation technology is considered to be one of the effective technologies for degrading trichloroethylene. Photocatalytic oxidation technology can decompose trichloroethylene gas in the air into inorganic small molecules such as CO2 and HCl, and has the advantages of environmental friendliness, low energy consumption and high efficiency. As the place where the photocatalytic reaction occurs, the photocatalytic reactor must have high conversion efficiency and be easy to use. In order to improve the interaction between trichloroethylene molecules-catalyst (surface mass transfer) and light-photocatalyst (photon transfer), researchers have been committed to developing new photocatalytic reactors, such as fluidized bed photocatalytic reactors and fixed bed photocatalytic reactors.

[0003] The invention patent with application number CN201710459128.8 discloses a multi-tray internal diffusion vertical plug flow photocatalytic reactor, which includes a lamp tube, a quartz sleeve, a spiral ascending tray, a catalyst tray and a photocatalytic reactor inlet and outlet. When pollutants enter the photocatalytic reactor, no backflow and vortex will appear in the flow direction of the pollutants, so that the normal catalytic reaction will not be interrupted and the reaction will be more complete; and the maximum degree of mixing is achieved on the plane perpendicular to the flow direction, further improving the photocatalytic reaction efficiency of each layer of catalyst. However, the structure of the photocatalytic reactor is relatively complex, which greatly increases the difficulty of processing. On the other hand, due to the arrangement of the spiral tray, the airflow will lose a large amount of kinetic energy when flowing inside the reactor, which will cause a large pressure drop, thereby increasing energy consumption.

[0004] The invention patent with application number CN201810643919.0 discloses a wave plate photocatalytic reactor, which is equipped with an ultraviolet light component, a wave plate quartz glass slide, and a quartz cover plate. The photocatalytic reactor uses a V-shaped groove to increase the contact area between the reactant and the photocatalyst, prolong the residence time of the pollutants in the reactor, increase the frequency of collision between the reactant and the active points on the surface of the photocatalyst, and can significantly improve the photocatalytic efficiency. However, the structure of the V-shaped groove will cause uneven distribution of pollutants in the airflow of the groove, and more pollutants will accumulate in some grooves, which is not conducive to the photocatalytic reaction.

[0005] In summary, the prior art has the following problems:

[0006] (1) The specific surface area of ​​photocatalysts loaded in existing photocatalytic reactors is small, which limits the contact area between pollutants and photocatalysts, resulting in low photocatalytic reaction efficiency;

[0007] (2) The airflow distribution inside the existing photocatalytic reactor is uneven, which will cause the accumulation of pollutants at certain locations, limiting the light-photocatalyst (photon transfer), which is not conducive to the efficient photocatalytic reaction;

[0008] (3) The residence time of pollutants in existing photocatalytic reactors is too short, which greatly limits the mass transfer between pollutants and photocatalysts and reduces the photocatalytic degradation efficiency. Summary of the invention

[0009] Technical problem to be solved: In response to the above technical problems, the present invention provides a sinusoidal wall-annular photocatalytic reactor and its application in degrading gaseous pollutants, which can effectively solve the shortcomings of the above-mentioned photocatalytic reactor, such as the small specific surface area of ​​the photocatalyst loaded in the photocatalytic reactor, the uneven distribution of the air flow velocity in the photocatalytic reactor, and the too short residence time of the pollutants.

[0010] Technical solution: In the first aspect, the present invention provides a sinusoidal wall annular photocatalytic reactor, comprising a reactor body, a light source is provided on the central axis of the reactor body, the inner wall of the reactor body is a sinusoidal wall, and a photocatalyst layer is provided on the inner wall, an air inlet is provided at one end of the reactor body, and an air outlet is provided at the other end.

[0011] Preferably, the sinusoidal wall surface conforms to the |Asin(ωx)| function, wherein A is the amplitude and ω is the angular frequency.

[0012] Furthermore, the amplitude A has a value of 1≤A≤7.

[0013] Furthermore, the value of the angular frequency ω is 0.15≤ω≤2.

[0014] Preferably, the gas inlet and the gas outlet are both cylindrical and perpendicular to the central axis of the reactor body.

[0015] Furthermore, the height H of the air inlet and the air outlet is in the range of 10 mm ≤ H ≤ 100 mm, and the diameter D1 is in the range of 5 mm ≤ D1 ≤ 25 mm.

[0016] Preferably, rubber sealing rings are provided between the air inlet and the air outlet and the reactor body.

[0017] Preferably, the reactor body is tubular, the tube length L has a value range of 100mm≤L≤1000mm, and the diameter is 25mm≤D2≤200mm.

[0018] Preferably, the light source is arranged inside the reactor body via a bracket.

[0019] In a second aspect, the present invention provides the use of the sinusoidal wall-surface annular photocatalytic reactor described in the first aspect in degrading gaseous pollutants.

[0020] The working principle of the photocatalytic reactor of the present invention:

[0021] First, turn on the light source. When trichloroethylene enters the photocatalytic reactor, it first diffuses fully at the air inlet, and the airflow directly hits the air inlet wall, and then flows into the main body of the sinusoidal wall annular reactor. When the trichloroethylene airflow passes through the main body of the sinusoidal wall annular reactor, it reacts with the photocatalyst coated on the sinusoidal wall to generate HCl and H2O, which are finally discharged from the air outlet.

[0022] Computational fluid dynamics (CFD) numerical simulation is used to guide the structural design and optimization of the photocatalyst.

[0023] The chemical reaction kinetic equation is as follows:

[0024]

[0025] Where, K0: intrinsic rate constant, which reflects the speed of the reaction;

[0026] I: radiation intensity on the photocatalyst surface;

[0027] K1, K2, K3, K4: Langmuir adsorption equilibrium constants, whose values ​​are 0.1074, 0.0005, 0.2281, 0.3955 μmol / L, respectively;

[0028] R: chemical reaction rate;

[0029] α: Photogenerated electron-hole efficiency, its value is 0.61;

[0030] CR : Trichloroethylene gas concentration;

[0031] C W : water vapor concentration;

[0032] The governing equations of the standard k–ε model are as follows:

[0033]

[0034] Where: G k : turbulent kinetic energy caused by the mean velocity gradient;

[0035] G b : turbulent kinetic energy generated by buoyancy;

[0036] Y M : Contribution of wave expansion to the total dissipation rate in compressible turbulence;

[0037] G 1ε , C 2ε , C 3ε : Their values ​​are 1.44, 1.92, and 1.3 respectively;

[0038] σ k : The value is 1.0;

[0039] C μ : The value is 0.09;

[0040] σ ε : represents the turbulent Prandtl number;

[0041] ρ: density of the fluid;

[0042] k: turbulent kinetic energy;

[0043] ε: turbulent kinetic energy dissipation rate;

[0044] S k : diffusion term of turbulent kinetic energy;

[0045] S ε : diffusion term of turbulent kinetic energy dissipation rate;

[0046] Beneficial effects: 1) Trichloroethylene gas enters from the air inlet, and the air inlet direction is perpendicular to the axis direction of the main structure of the sinusoidal wall annular reactor. The airflow directly impacts the air inlet wall, passes through the main structure of the sinusoidal wall annular reactor and is discharged from the air outlet. This structure effectively avoids damage to the lamp source caused by direct impact of the airflow;

[0047] 2) The sinusoidal structure wall is used as a carrier of the photocatalyst. By adjusting the amplitude A and angular frequency ω, the photocatalytic reactor has a larger reaction area and a lower pressure drop, which increases the collision between pollutants and the active sites of the photocatalyst. At the same time, the viscosity of the fluid is adjusted to make the flow field inside the photocatalyst more stable. Compared with the annular photocatalyst with a smooth wall, the degradation efficiency of trichloroethylene in the annular photocatalyst with an amplitude A=6 sinusoidal wall is increased by 5.13%. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Schematic diagram of the structure of a sinusoidal wall-surface annular photocatalytic reactor of the present invention, wherein (a) is a cross-sectional schematic diagram of a smooth wall-surface annular photocatalytic reactor (Comparative Example 1), (b) is a schematic diagram of the dimensions of the photocatalyst, and (c) is a cross-sectional and structural schematic diagram of a sinusoidal wall-surface annular photocatalytic reactor (Example 6);

[0049] Sequence numbers in the figure: 1, air inlet, 2, light source bracket, 3, catalyst coating layer, 4, light source, 5, air outlet, 6, reactor body;

[0050] Figure 2 Schematic diagram of the structural comparison of the main body of the sinusoidal wall annular reactor with different amplitudes;

[0051] Figure 3 Schematic diagram of the structural comparison of the main body of the sinusoidal wall-surface annular reactor with different angular frequencies;

[0052] Figure 4 It is a solid diagram of an annular photocatalytic reactor with 6sin(x) type wall in equal proportion;

[0053] Figure 5 It is a diagram of the experimental device for photocatalytic degradation of trichloroethylene gas in a ring-shaped photocatalytic reactor with 6sin(x)-shaped walls in equal proportion;

[0054] Figure 6 Schematic diagram of the radiation intensity distribution of the sinusoidal wall-surface annular photocatalytic reactor with different amplitudes at the XY center plane;

[0055] Figure 7 Schematic diagram of velocity distribution of sinusoidal wall-surface annular photocatalytic reactor with different amplitudes at the XY center plane;

[0056] Figure 8 is the average velocity of the sinusoidal wall-surface annular photocatalytic reactor with different amplitudes distributed along the X-axis direction;

[0057] Fig. 9 Schematic diagram of turbulent viscosity distribution at the XY center plane of a sinusoidal wall-surface annular photocatalytic reactor with different amplitudes;

[0058] Fig.10The turbulent viscosity along the X-axis direction of the sinusoidal wall-surface annular photocatalytic reactor with different amplitudes;

[0059] Fig.11 Schematic diagram of concentration distribution at the XY center plane of a sinusoidal wall-surface annular photocatalytic reactor with different amplitudes;

[0060] Fig.12 is the concentration distribution along the X-axis direction of the sinusoidal wall-surface annular photocatalytic reactor with different amplitudes;

[0061] Fig.13 Schematic diagram of the radiation intensity distribution at the XY center plane of a sinusoidal wall-surface annular photocatalytic reactor with different angular frequencies;

[0062] Fig.14 Schematic diagram of turbulent viscosity distribution at the XY center plane of a sinusoidal wall-surface annular photocatalytic reactor with different angular frequencies;

[0063] Fig.15 Schematic diagram of concentration distribution at the XY center plane of a sinusoidal wall-shaped annular photocatalytic reactor with different angular frequencies.

[0064] Fig.16 Schematic diagram of the comparison between the experimental and simulation results of a 6sin(x) type wall-surface annular photocatalytic reactor at different inlet velocities. DETAILED DESCRIPTION

[0065] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0066] Example 1

[0067] like Figure 1 As shown, a sinusoidal wall-shaped annular photocatalytic reactor, such as Figure 1 As shown in (a), it comprises a reactor body 6, a light source 4 is arranged on the central axis of the reactor body 6 through a bracket 2, the bracket 2 and the reactor body 6 are integrally formed, the light source 4 is coaxial with the reactor body 6, and the inner side wall of the reactor body 6 is a sinusoidal wall surface (such as Figure 1 (c)), and a catalyst TiO2 is provided on the inner wall, one end of the reactor body 6 is connected to the air inlet 1 by bolts, and the other end is connected to the air outlet 5 by bolts, and rubber sealing rings are provided between the air inlet and the air outlet and the reactor body.

[0068] like Figure 1 (b) shows: the air inlet and the air outlet are both cylindrical and perpendicular to the central axis of the reactor body. The height H of the air inlet and the air outlet is: H = 20 mm, and the diameter D1 is: D1 = 12 mm; the reactor body is tubular, and the tube length L is in the range of: L = 250 mm, and the diameter is D2 = 44 mm;

[0069] The above-mentioned sinusoidal wall surface is sin(x) (denoted as A-1).

[0070] Embodiment 2:

[0071] Similar to Example 1, the difference is that the sinusoidal wall surface is 2sin(x) (denoted as A-2).

[0072] Embodiment 3:

[0073] Similar to Example 1, the difference is that the sinusoidal wall surface is 3sin(x) (denoted as A-3).

[0074] Embodiment 4:

[0075] Similar to Example 1, the difference is that the sinusoidal wall surface is 4sin(x) (denoted as A-4).

[0076] Embodiment 5:

[0077] Similar to Example 1, the difference is that the sinusoidal wall surface is 5sin(x) (denoted as A-5).

[0078] Embodiment 6:

[0079] Similar to Example 1, the difference is that the sinusoidal wall surface is 6sin(x) (denoted as A-6).

[0080] Embodiment 7:

[0081] Similar to Example 1, the difference is that the sinusoidal wall surface is 7sin(x) (denoted as A-7).

[0082] Embodiment 8:

[0083] Similar to Example 1, the difference is that the sinusoidal wall surface is sin(0.15x) (denoted as ω-0.15).

[0084] Embodiment 9:

[0085] Similar to Example 1, the difference is that the sinusoidal wall surface is sin(0.25x) (denoted as ω-0.25).

[0086] Embodiment 10:

[0087] Similar to Example 1, the difference is that the sinusoidal wall surface is sin(0.5x) (denoted as ω-0.5).

[0088] Embodiment 11:

[0089] Similar to Example 1, the difference is that the sinusoidal wall surface is sin(1.5x) (denoted as ω-1.5).

[0090] Embodiment 12:

[0091] Similar to Example 1, the difference is that the sinusoidal wall surface is sin(2x) (denoted as ω-2).

[0092] Embodiment 13:

[0093] In order to verify the FLUENT calculation results, a circular photocatalytic reactor with a 6sin(x) wall of equal proportion was designed and manufactured to perform a trichloroethylene gas degradation experiment (the experimental device is shown in Figure 5 shown), i.e. Figure 4 As shown (recorded as A-6 experimental data).

[0094] Comparative Example 1:

[0095] Similar to Example 1, the difference is that no sinusoidal wall surface is used, that is, a smooth wall surface (denoted as A-0).

[0096] Performance Testing:

[0097] 1. Sinusoidal wall-surface annular photocatalytic reactors with different amplitudes (such as Figure 2 Effect of (as shown) on the degradation efficiency of trichloroethylene gas

[0098] 1.1 Radiation intensity: At the entrance speed of 1.5m / s, the radiation intensity of the light source is 75W / m 2 , the photocatalytic degradation of trichloroethylene with an initial concentration of 400 ppm was investigated when the amplitude ranged from 1 to 7 and the angular frequency was 1. Figure 6 is the radiation intensity distribution at the XY center plane, from Figure 6 It can be seen that the surface of the photocatalyst coated in the smooth wall model has a higher radiation intensity, and as the amplitude increases, the radiation intensity at the catalyst surface becomes lower and lower. The radiation intensity at the photocatalyst surface of each reactor is 73.21, 68.52, 65.03, 62.57, 60.97, 60.64, 60.52 and 60.48 W / m 2 .

[0099] 1.2 Fluid velocity: Figure 7 The velocity distribution cloud diagram of the reactors with different structures at the inlet velocity of 1.5m / s at the XY center plane. It can be seen from the figure that the maximum velocity appears at the outlet. At the same time, with the increase of amplitude, the maximum velocity in each reactor decreases first and then increases, and is lower than the smooth wall model. When the amplitude is 6 (that is, the sinusoidal wall is 6sin(x) type), the maximum velocity is 1.883m / s, which is 0.05m / s less than the original model. Figure 8 is the average velocity distribution along the X-axis, Figure 8It can be seen that as the amplitude increases, the average speed along the X-axis direction also increases. When the amplitude A=6, the average speed in the X-axis direction is the most uniform.

[0100] 1.3 Turbulent viscosity: Due to the existence of turbulent viscosity, the fluid will randomly pulsate to produce eddy diffusion, resulting in different fluid velocities at the flow interface. Fig. 9 The turbulent viscosity distribution of the reactor with different amplitudes in the XY plane. Regardless of the amplitude, the turbulent viscosity reaches the maximum value near the inlet, and there is also a significant change near the outlet. As the amplitude increases, the turbulent viscosity decreases. The decrease in turbulent viscosity will prolong the residence time of trichloroethylene at this location, increase the contact time between trichloroethylene and the photocatalyst surface, and is conducive to the photocatalytic reaction. Fig.10 The turbulent viscosity of the sinusoidal wall-shaped annular photocatalytic reactor with different amplitudes distributed along the X-axis direction shows that the change of turbulent viscosity is inversely proportional to the amplitude. As the amplitude increases, the turbulent viscosity decreases, and the change is more obvious 100mm in front of the catalyst.

[0101] 1.4 Trichloroethylene gas concentration: The trichloroethylene concentration distribution at the XY center plane of different reactors is as follows Fig.11 As shown, the photocatalytic conversion rates of trichloroethylene in each reactor are 58.07%, 58.17%, 59.33%, 60.36%, 61.47%, 62.18%, 63.2% and 62.8% respectively. With the increase of amplitude, the photocatalytic conversion of trichloroethylene first increases and then decreases. When the amplitude A=6, the photocatalytic conversion rate of trichloroethylene is the highest. Fig.12 The concentrations of the sinusoidal wall-surface annular photocatalytic reactors with different amplitudes along the X-axis are shown in Figure 2. This indicates that as the amplitude increases, the concentration distribution becomes more uniform and the degradation effect becomes higher. Among them, model A-6 has the highest degradation efficiency.

[0102] Among them, in the model with amplitude changing from 1 to 4, the radiation intensity on the sinusoidal wall surface decreases greatly, and in the model with amplitude changing from 5 to 7, the radiation intensity on the sinusoidal wall surface decreases less. The model with the largest wall radiation intensity is the non-sinusoidal wall photocatalytic reactor, while the conversion rate of trichloroethylene increases in the model with amplitude changing from 1 to 6. Combining the fluid velocity and turbulent viscosity, the fluid velocity of model A-6 is the most uniform and the turbulent viscosity is also very low, indicating that the degree of radiation intensity reduction caused by the increase in amplitude of the present invention will not affect the photocatalytic conversion rate of trichloroethylene. The main reasons for improving the photocatalytic conversion rate of trichloroethylene are high uniformity of airflow, low turbulent viscosity and large contact area between trichloroethylene gas and photocatalyst.

[0103] 2. Sinusoidal wall-surface annular photocatalytic reactors with different angular frequencies (such as Figure 3 Effect of (as shown) on the degradation efficiency of trichloroethylene gas

[0104] 2.1 Radiation intensity: At the inlet velocity of 1.5m / s, the radiation intensity is 75W / m 2 When the initial concentration of trichloroethylene is 400 ppm, the effect of the sinusoidal wall-shaped annular photocatalytic reactor with angular frequencies of 0.15, 0.25, 0.5, 1.5, 2 and amplitude of 1 on turbulent viscosity is investigated respectively. Fig.13 The radiation intensity distribution of the sinusoidal wall-surface annular photocatalytic reactor with different angular frequencies on the XY plane. The radiation intensity at the wall of the photocatalytic reaction is 65.52, 65.03, 63.67 and 61.97 W / m 2 It can be seen that as the angular frequency gradually increases, the radiation intensity gradually decreases.

[0105] 2.2 Turbulent viscosity: Fig.14 The turbulent viscosity distribution of the sinusoidal wall-surface annular photocatalytic reactor with different angular frequencies on the XY plane. When the angular frequency changes from 0.25 to 0.5, the maximum value of the turbulent viscosity changes very little, increasing by 0.000001Pa·s; when the angular frequency changes to 1.5, the maximum value of the turbulent viscosity decreases by 0.00001Pa·s, which is 10 times the previous change.

[0106] 2.3 Trichloroethylene gas concentration: Fig.15 The concentration distribution of trichloroethylene in different reactors on the XY plane. It can be seen from the figure that the degradation trend of trichloroethylene is consistent in each reactor. With the increase of angular frequency, the concentration of trichloroethylene at the reactor wall is getting lower and lower. However, the photocatalytic trichloroethylene conversion rate of each reactor is not very significant, which is 58.13%, 58.95%, 59.06% and 58.78% respectively.

[0107] Among them, as the angular frequency increases, the turbulent viscosity can be reduced and the residence time of trichloroethylene in the reactor can be prolonged. However, the increase in angular frequency will also reduce the radiation intensity on the catalyst surface, which also explains why the photocatalytic conversion of trichloroethylene first increases and then decreases with the increase in angular frequency. Compared with the amplitude, the angular frequency has little effect on the degradation efficiency of trichloroethylene.

[0108] Experimental and simulation results

[0109] Fig.16The figure shows a comparison between the experimental and simulation results of the photocatalytic conversion rate of trichloroethylene at different inlet velocities in a 6sin(x) type annular photocatalytic reactor. It can be seen from the figure that the simulation results of A-6 are higher than the experimental results. The main reasons for this phenomenon may be two aspects: (1) the air tightness of the device is poor and there is leakage; (2) compared with the simulation model, the roughness of the physical model is larger, which will cause the trichloroethylene gas to mix in the pipe, causing the trichloroethylene concentration in the reactor to increase. At the same time, the error between the simulation results and the experimental results is within 5%. Therefore, the fluid simulation model used in the present invention is correct and the simulation results are accurate and reliable.

[0110] The photocatalytic reactor models A-1 to A-6 prepared by the present invention have a degradation efficiency of 0.1% higher than that of the conventional smooth wall reactor model A-0, 1.26% higher than that of the conventional smooth wall reactor model A-2, 2.29% higher than that of the conventional smooth wall reactor model A-3, 3.4% higher than that of the conventional smooth wall reactor model A-4, 4.11% higher than that of the conventional smooth wall reactor model A-6, and 4.73% higher than that of the conventional smooth wall reactor model A-7. In general, the prepared models have better degradation effects than the conventional reactor models.

[0111] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sinusoidal wall-surface annular photocatalytic reactor, characterized in that: The invention comprises a reactor body (1), wherein a light source (2) is arranged on the central axis of the reactor body (1), the inner wall of the reactor body (1) is a sinusoidal wall surface, and a photocatalyst layer (3) is arranged on the inner wall, and an air inlet (4) is arranged at one end of the reactor body (1), and an air outlet (5) is arranged at the other end.

2. The sinusoidal wall-surface annular photocatalytic reactor according to claim 1, characterized in that: The sinusoidal wall conforms to |Asin(ω x )│function, where A is the amplitude and ω is the angular frequency.

3. A sinusoidal wall-surface annular photocatalytic reactor according to claim 2, characterized in that: The amplitude A has a value of 1 ≤ A ≤ 7.

4. The sinusoidal wall-surface annular photocatalytic reactor according to claim 2, characterized in that: The angular frequency ω - The value of is 0.15 ≤ ω≤ 2.

5. The sinusoidal wall-surface annular photocatalytic reactor according to claim 1, characterized in that: The gas inlet and the gas outlet are both cylindrical and perpendicular to the central axis of the reactor body.

6. The sinusoidal wall-surface annular photocatalytic reactor according to claim 5, characterized in that: The height H of the air inlet and the air outlet is in the range of 10 mm ≤ H ≤ 100 mm, and the diameter D1 is in the range of 5 mm ≤ D1≤ 25 mm.

7. The sinusoidal wall-surface annular photocatalytic reactor according to claim 1, characterized in that: Rubber sealing rings are arranged between the air inlet and the air outlet and the reactor body.

8. The sinusoidal wall-surface annular photocatalytic reactor according to claim 1, characterized in that: The reactor body is tubular, the tube length L is in the range of 100 mm ≤ L ≤ 1000 mm, and the diameter is 25 mm ≤ D2 ≤ 200 mm.

9. The sinusoidal wall-surface annular photocatalytic reactor according to claim 1, characterized in that: The light source is arranged inside the reactor body via a bracket (6).

10. Use of the sinusoidal wall-surface annular photocatalytic reactor according to any one of claims 1 to 9 in the degradation of gaseous pollutants.

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