A spiral falling film photocatalytic sewage treatment experimental device

Abstract

The invention relates to a spiral falling film photocatalytic sewage treatment experimental device, comprising a reactor, an illumination unit and a spiral falling film oxygenation component. The side wall of the reactor is made of a light-transmitting material. The illumination unit comprises a plurality of LED light sheets, each of which is evenly distributed with a plurality of LED lamp beads. The LED light sheets are closely attached to the outer side wall of at least one side of the reactor, and the lamp beads face the inside of the reactor to provide close-range uniform illumination for the reactor. The spiral falling film oxygenation component is arranged at the upper part of the reactor and comprises a plurality of vertical spiral liquid columns. Sewage inlet water forms a falling film along the outer side surface of the spiral liquid column and flows into the reactor. A heat dissipation device is arranged on one side or both sides of the LED light sheet to dissipate heat for the light sheet in time, so as to ensure that the LED lamp beads can work at a higher power and provide illumination for the reactor.

Description

Technical Field

[0001] The invention belongs to the technical field of photocatalytic sewage treatment, and in particular relates to a spiral falling film photocatalytic sewage treatment experimental device. Background Art

[0002] In the field of sewage treatment, photocatalytic degradation technology has high treatment efficiency and is environmentally friendly. It uses solar energy to degrade organic pollutants into harmless small molecules. Photocatalytic degradation performance is the most basic and important indicator for evaluating the overall performance of photocatalysts. Existing photocatalytic degradation performance evaluation devices mostly use artificial light sources. Due to the characteristics of the artificial light source itself, it needs to be separated from the reactor by a certain distance, resulting in a large attenuation of the actual light intensity reaching the reaction system, resulting in low overall photocatalytic degradation efficiency. Moreover, the illumination of the artificial light source is not uniform. If the distance between the artificial light source and the reactor is shortened, the temperature of the reactor will rise, affecting the efficiency of the photocatalyst.

[0003] In addition, the structure of the photocatalytic reactor is relatively primitive, generally in the form of a reaction vessel combined with stirring, which to a certain extent restricts the overall performance improvement of the photocatalytic degradation technology. For example, the uniformity and intensity of the light in the reactor, the material mixing efficiency, and the oxygen mass transfer efficiency during the degradation process all need to be further improved. In particular, the oxygen mass transfer efficiency, because the oxygen content in the system is directly related to the generation of photocatalytic active oxygen species, and active oxygen species are the key to the continuous degradation of target pollutants. Summary of the invention

[0004] In view of the above problems, the present invention provides a spiral falling film photocatalytic sewage treatment experimental device, comprising a reactor, an illumination unit and a spiral falling film oxygenation component, the side wall of the reactor is made of a light-transmitting material, the illumination unit comprises a plurality of LED light sheets, each of which is evenly distributed with a plurality of LED lamp beads, the LED light sheets are closely attached to the outer wall of at least one side of the reactor, the lamp beads face the interior of the reactor, and provide close-range uniform illumination for the reactor;

[0005] The spiral falling film oxygenation assembly is arranged at the upper part of the reactor and includes a plurality of vertical spiral liquid columns. The sewage inlet forms a falling film along the outer side of the spiral liquid column and flows into the reactor.

[0006] A heat dissipation device is provided on one or both sides of the LED lamp sheet to dissipate heat for the lamp sheet in time, thereby ensuring that the LED lamp beads can work at a higher power and provide illumination for the reactor.

[0007] The present invention abandons the traditional artificial single bulb light source, which has strong central light energy, high temperature, uneven light energy distribution, and cannot be too close to the reactor. The present invention adopts LED lamp sheets and LED lamp beads. The lamp beads are small in size and can flexibly adjust the distribution on the lamp sheet. The lamp sheet is in sheet form and simple in form. It can be directly attached to the outer surface of the reactor. When in use, the temperature of the LED lamp beads is not high, and does not affect the temperature of the sewage inside the reactor. It can also provide uniform lighting for the reactor and improve the reaction efficiency. The heat dissipation device can dissipate heat for the lamp sheet in time. The sewage inlet water enters the reactor through the spiral falling film oxygenation component, and the sewage forms a spiral falling film flow on the surface of the spiral liquid column, which increases the gas-liquid effective mass transfer area, strengthens the oxygen mass transfer and the formation of active oxygen species during the degradation process, thereby improving the photocatalytic degradation efficiency.

[0008] Optionally, the reactor is a cube, the LED light sheet is attached to the outer surface of at least one side of the reactor, and the LED lamp beads face the inside of the reactor; the top cover of the reactor is detachable, which is convenient for cleaning the inside of the reactor;

[0009] The top cover is evenly provided with a plurality of water inlet interfaces, which penetrate the top cover, the top of the spiral liquid column is connected to the bottom of the water inlet interface, and the top of the water inlet interface is connected to an external sewage source to input sewage into the spiral liquid column.

[0010] Further optionally, the water inlet interface is a sleeve structure, including an internal lamp-through tube and an external water-through tube, the lamp-through tube and the water-through tube are concentrically arranged, the lamp-through tube and the water-through tube are not connected to each other, and the side of the water-through tube is connected to an external sewage water source or a heat dissipation water pipe; the top opening of the spiral liquid column is connected to the bottom of the lamp-through tube;

[0011] A conical side wall is provided at the bottom of the water pipe, so that the bottom of the water pipe forms a closing end, thereby allowing the sewage in the water pipe to flow down along the outer surface of the spiral liquid column in the form of a falling film.

[0012] Optionally, the spiral liquid column is wound in a clockwise or counterclockwise spiral. The interior of the spiral liquid column is hollow and is used to place an LED light bar. The bottom of the LED light bar is at the bottom of the spiral liquid column, and the top of the LED light bar passes through the spiral liquid column and then extends out from the lamp tube to connect to an external power supply. The bottom of the spiral liquid column is above the liquid surface of the reactor.

[0013] Optionally, the LED lamp beads are evenly distributed in a matrix shape on the front of the LED light sheet, and the LED light sheet is of a conventional structure and is provided with an aluminum sheet for heat dissipation;

[0014] The heat dissipation device includes a first heat dissipation water pipe and a second heat dissipation water pipe. The first heat dissipation water pipe is arranged on the front side of the LED lamp sheet, and the second heat dissipation water pipe is arranged on the back side. The first heat dissipation water pipe and the second heat dissipation water pipe are respectively coiled around the front side and the back side of the LED lamp sheet in a serpentine shape. The water inlet end of the second heat dissipation water pipe is connected to an external sewage water source, and the water outlet end is connected to the water inlet end of the first heat dissipation water pipe; the water outlet end of the first heat dissipation water pipe is connected to the top of the spiral liquid column, and the sewage flows along the second heat dissipation water pipe and the first heat dissipation water pipe in sequence, which can absorb the heat of the LED lamp sheet and cool the lamp sheet, while the sewage is preheated and heated.

[0015] Optionally, two adjacent sides of the reactor are respectively paved with LED light sheets;

[0016] Reflective sheets are attached to the outer surfaces of the other two sides of the reactor. The front side of the reflective sheet is a bright mirror surface facing the inside of the reactor, reflecting the received light back to the reactor. The back side of the reflective sheet is a light-isolating material to prevent light from passing through.

[0017] Optionally, LED light sheets are laid on the four sides of the reactor, so that light can propagate, reflect, re-propagate, and re-reflect in all directions in the reactor, thereby improving light energy utilization.

[0018] Optionally, a reflective sheet is attached to the outer surface of the bottom surface of the reactor, the front side of the reflective sheet faces the inside of the reactor and reflects the received light back to the reactor, and the back side of the reflective sheet is made of light-isolating material to prevent light from passing through.

[0019] Optionally, a plurality of stirring shafts are evenly arranged inside the reactor, and a plurality of stirring paddles are evenly arranged on the portion of the stirring shaft below the liquid level in the reactor. The stirring paddles are plate-shaped and have reflective sheets on both sides so that the stirring paddles can reflect the received light while rotating.

[0020] Further optionally, the stirring paddle is inclined, and the central axis of the stirring paddle remains vertical;

[0021] A plurality of protruding edges are evenly arranged on both sides of the stirring paddle. The protruding edges are horizontal or vertical, and the protruding edges protrude in a direction away from the side where they are located. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the spiral falling film photocatalytic sewage treatment experimental device;

[0023] Figure 2 is a schematic diagram of the water inlet interface;

[0024] Figure 3 is a schematic diagram of an LED light sheet;

[0025] Figure 4 Schematic diagram of the stirring shaft.

[0026] In the accompanying drawings, 1-reactor, 2-LED lamp sheet, 3-LED lamp bead, 4-protruding edge, 5-spiral liquid column, 6-water inlet interface, 7-lamp tube, 8-water pipe, 9-first heat dissipation water pipe, 10-second heat dissipation water pipe, 11-reflecting sheet, 12-stirring shaft, 13-stirring paddle. DETAILED DESCRIPTION

[0027] This embodiment provides a spiral falling film photocatalytic sewage treatment experimental device, such as Figure 1-Figure 4 As shown, it includes a reactor 1, an illumination unit and a spiral falling film oxygenation component. The side wall of the reactor is made of a light-transmitting material. The illumination unit includes a plurality of LED light sheets 2. A plurality of LED lamp beads 3 are evenly distributed on each LED light sheet 2. The LED light sheet 2 is closely attached to the outer wall of at least one side of the reactor, and the lamp beads face the inside of the reactor, so as to provide close-range uniform illumination for the reactor.

[0028] The spiral falling film oxygenation assembly is arranged at the upper part of the reactor and comprises a plurality of vertical stainless steel spiral liquid columns 5. The sewage inlet forms a falling film along the outer side of the spiral liquid column 5 and flows into the reactor.

[0029] A heat dissipation device is provided on one or both sides of the LED lamp sheet 2 to dissipate heat for the lamp sheet in time, thereby ensuring that the LED lamp beads 3 can work at a higher power and provide illumination for the reactor.

[0030] Optionally, the reactor is a cube, the LED light sheet 2 is attached to the outer surface of at least one side of the reactor, and the LED lamp beads 3 face the inside of the reactor; the top cover of the reactor is detachable to facilitate cleaning of the inside of the reactor;

[0031] The top cover is evenly provided with a plurality of water inlet interfaces 6, which penetrate the top cover, the top of the spiral liquid column 5 is connected to the bottom of the water inlet interface 6, and the top of the water inlet interface 6 is connected to an external sewage source, and sewage is input into the spiral liquid column 5. Granular photocatalysts are added into the reactor, and existing photocatalysts can be applied to the reactor of the present invention.

[0032] Further optionally, the water inlet interface 6 is a sleeve structure, including an internal light tube 7 and an external water pipe 8, the light tube 7 and the water pipe 8 are concentrically arranged, the light tube 7 and the water pipe 8 are not connected to each other, and the side of the water pipe 8 is connected to an external sewage water source or a heat dissipation water pipe; the top opening of the spiral liquid column 5 is connected to the bottom of the light tube 7, and waterproof treatment is performed to prevent sewage from flowing into the spiral liquid column 5;

[0033] A conical side wall is provided at the bottom of the water pipe 8 , so that the bottom of the water pipe 8 forms a closed end, thereby allowing the sewage in the water pipe 8 to flow down along the outer surface of the spiral liquid column 5 .

[0034] Further optionally, an air inlet is provided on the side of the water pipe 8 for introducing air into the water pipe to enhance gas-liquid mass transfer through falling film and increase the oxygen content of the photocatalytic degradation system.

[0035] Optionally, the spiral liquid column 5 is wound in a clockwise or counterclockwise spiral. The interior of the spiral liquid column 5 is hollow and is used to place an LED light bar. The bottom of the LED light bar is at the bottom of the spiral liquid column 5, and the top of the LED light bar passes through the spiral liquid column 5 and then extends out from the lamp tube 7 to connect to an external power supply. The bottom of the spiral liquid column 5 is above the liquid surface of the reactor.

[0036] The sewage flows down through several spiral liquid columns 5, and can evenly enter the top of the reactor. The sewage flows down along the outer side of the spiral liquid column 5 to form a spiral falling film. The thickness of the liquid film is not large, which is conducive to enhancing gas-liquid mass transfer and increasing the oxygen content in the sewage. An LED light bar can be set inside the spiral lamp column to preheat the sewage water. At the same time, the sewage dissipates heat and cools the LED light bar to prevent the LED light bar from overheating. At the same time, it provides top light energy for the water body below. The above method is simple and convenient. The light bar is isolated from the sewage to avoid leakage and short circuit. The top of the light bar passes through the lamp tube 7, which is convenient for connecting an external power supply.

[0037] Optionally, the LED lamp beads 3 are evenly distributed in a matrix on the front of the LED lamp sheet 2, and the LED lamp sheet 2 is of a conventional structure and is provided with an aluminum sheet for heat dissipation;

[0038] The heat dissipation device includes a first heat dissipation water pipe 9 and a second heat dissipation water pipe 10. The first heat dissipation water pipe 9 is arranged on the front side of the LED light sheet 2, and the second heat dissipation water pipe 10 is arranged on the back side. The first heat dissipation water pipe 9 and the second heat dissipation water pipe 10 are respectively coiled around the front side and the back side of the LED light sheet 2 in a serpentine shape. The water inlet end of the second heat dissipation water pipe 10 is connected to an external sewage water source, and the water outlet end is connected to the water inlet end of the first heat dissipation water pipe 9; the water outlet end of the first heat dissipation water pipe 9 is connected to the top of the spiral liquid column 5, and the sewage flows along the second heat dissipation water pipe 10 and the first heat dissipation water pipe 9 in sequence, which can absorb the heat of the LED light sheet 2, cool the light sheet, ensure that the light sheet can work at a higher power, provide greater light energy, and at the same time the sewage is preheated and heated.

[0039] Optionally, two adjacent sides of the reactor are respectively paved with LED light sheets 2, for example, one side is paved with one or more LED light sheets 2, so that the light sheets can completely cover the corresponding side of the reactor, and adjacent light sheets do not overlap;

[0040] Reflective sheets 11 are attached to the outer surfaces of the other two sides of the reactor. The front side of the reflective sheet 11 is a bright mirror surface facing the inside of the reactor, reflecting the received light back to the reactor. The back side of the reflective sheet 11 is made of light-isolating material to prevent light from passing through.

[0041] The light emitted by the lamp on one side of the reactor shines into the interior of the reactor, and the light shines on the front of the reflector on the opposite side or the adjacent side, and the light is reflected back into the reactor. The back of the reflector prevents the light from passing through, and tries to keep most of the light in the reactor, so that the light energy can be fully utilized in the reactor.

[0042] Optionally, LED light sheets 2 are laid on all four sides of the reactor, for example, one side is laid with one or several LED light sheets 2, so that the light sheets can completely cover the corresponding side of the reactor, and adjacent light sheets do not overlap, so that light can propagate, reflect, re-propagate, and re-reflect in all directions within the reactor, thereby improving light energy utilization.

[0043] Optionally, a reflective sheet is attached to the outer surface of the bottom surface of the reactor, the front side of the reflective sheet faces the inside of the reactor and reflects the received light back to the reactor, and the back side of the reflective sheet is made of light-isolating material to prevent light from passing through. A reflective sheet can also be provided on the upper surface of the reactor top cover to reflect light back to the inside of the reactor.

[0044] The water inlet end of the second heat dissipation water pipe 10 of each side LED lamp piece 2 can be connected to an external sewage water source, or can be connected to the water inlet end of the second heat dissipation water pipe 10 of other lamp pieces, so that the sewage water passes through the heat dissipation water pipes on different sides in turn for heat exchange.

[0045] Optionally, the heat dissipation device further includes a fan, which is arranged outside the LED light sheet 2. One fan can be corresponding to one side for heat dissipation, or one fan can be corresponding to two adjacent sides for heat dissipation of the light sheets on the two adjacent sides. The fan is used as a supplementary heat dissipation means. When there are many LED light sheets 2 arranged on the side of the reactor, and the sewage cooling effect cannot keep up with the heat dissipation of the light sheets, the fan is arranged to assist in heat dissipation.

[0046] The present invention arranges an LED light sheet 2 on the side of the reactor, and arranges an LED light bar inside the spiral liquid column 5 on the upper part of the reactor, which can provide light energy from all directions, and the reflective sheets on the side and bottom of the reactor can reflect light, retain the light energy inside the reactor, and make full use of the light energy. Since the heat dissipation problem of the LED lamp beads 3 cannot be ignored, long-term operation will significantly increase the temperature of the reaction system and affect the catalytic efficiency, but the reaction system still requires a certain temperature to cooperate with the catalyst to exert the maximum efficiency. The present invention arranges a heat dissipation water pipe on the front and back sides of the LED light sheet 2, and passes sewage. The sewage takes away the heat of the light sheet, and at the same time, the sewage itself heats up to complete the heat exchange process. Similarly, the sewage flowing down the outer surface of the spiral liquid column 5 forms a film and exchanges heat with the internal LED light bar to cool the light bar. According to the reaction temperature required for the actual photocatalytic reaction, the number of light sheets through which the sewage enters is adjusted so that the sewage is heated to an appropriate temperature.

[0047] Since the LED light sheet 2 is attached to the side of the reactor, the water area closer to the side gets more light energy, and the water area closer to the center of the reactor gets less light energy. The traditional reactor is equipped with a stirring device to simply stir the water body to promote the uniform distribution of pollutants and catalysts and maintain the catalytic reaction. However, for a reactor with a larger volume, the difference in light energy in different water areas will drag down the efficiency of the entire reactor. In view of the above problems, the present invention provides the following solutions.

[0048] Optionally, a plurality of stirring shafts 12 are evenly arranged inside the reactor, and the top of the stirring shaft 12 passes through the top cover and is connected to an external motor to drive the stirring shaft 12 to rotate;

[0049] A plurality of stirring paddles 13 are evenly arranged on the stirring shaft 12 below the liquid level in the reactor. The stirring paddles 13 are plate-shaped and have reflective sheets attached to both sides so that the stirring paddles 13 can reflect the received light while rotating.

[0050] Further optionally, the stirring paddle 13 is inclined, and the central axis of the stirring paddle 13 remains vertical, that is, the stirring paddle 13 takes the stirring shaft 12 as the central axis, the top edge and the bottom edge of the stirring paddle 13 are not on the same vertical plane, and the two sides of the stirring paddle 13 can receive light from the horizontal and vertical directions;

[0051] A plurality of protruding edges 4 are evenly arranged on both sides of the stirring paddle 13. The protruding edges 4 are horizontal or vertical. The protruding edges 4 on the same side of the same stirring paddle 13 are parallel to each other. The protruding edges 4 on different sides of the same stirring paddle 13 may be parallel or non-parallel. The protruding edges 4 of different stirring paddles 13 may be parallel or non-parallel. The protruding edges 4 protrude in a direction away from the side where they are located. The surface of the protruding edges is arc-shaped.

[0052] The surface of the stirring paddle 13 designed by the present invention is affixed with a reflective sheet, the mirror surface of the reflective sheet faces outward, and the stirring paddle 13 is inclined. The stirring paddle 13 can receive light from the side of the reactor, light from the spiral liquid column 5 above, reflected light from other stirring paddles 13 of the same stirring shaft 12, and reflected light from stirring paddles 13 of other stirring shafts 12, that is, the stirring paddle 13 can receive light from all directions and then reflect the light out. At the same time, since the stirring paddle 13 is in a rotating state, the facing direction of the stirring paddle 13 changes at any time, so that the direction of the light received and reflected by the stirring paddle 13 also changes at any time, making the light propagation trajectory inside the reactor rich and varied, which helps to make full use of light energy. Moreover, the protruding edges 4 on the surface of the stirring paddle 13 can prevent photocatalyst particles from depositing on the surface of the stirring paddle 13 and shielding the mirror surface, and can also increase the direction difference of the light reflected from the side of the stirring paddle 13. The stirring paddle 13 near the side of the reactor reflects the light to the stirring paddle 13 closer to the inside of the reactor. After the step-by-step reflection between different stirring shafts 12, the water area near the center of the reactor can also obtain light energy, thereby improving the overall reaction efficiency of the reactor.

Claims

1. A spiral falling film photocatalytic sewage treatment experimental device, characterized in that: It includes a reactor, an illumination unit and a spiral falling film oxygenation component. The side wall of the reactor is made of a light-transmitting material. The illumination unit includes a plurality of LED light sheets. A plurality of LED lamp beads are evenly distributed on each LED light sheet. The LED light sheet is closely attached to the outer wall of at least one side of the reactor. The lamp beads face the inside of the reactor to provide close-range uniform illumination for the reactor. The spiral falling film oxygenation assembly is arranged at the upper part of the reactor and includes a plurality of vertical spiral liquid columns. The sewage inlet forms a falling film along the outer side of the spiral liquid column and flows into the reactor. A heat dissipation device is provided on one or both sides of the LED lamp sheet to dissipate heat in time for the lamp sheet, so as to ensure that the LED lamp beads can work at a higher power and provide illumination for the reactor; The top cover of the reactor is evenly provided with a plurality of water inlet interfaces, and the water inlet interfaces penetrate the top cover; The water inlet interface is a sleeve structure, including an internal lamp-through tube and an external water-through tube, the lamp-through tube and the water-through tube are concentrically arranged, the lamp-through tube and the water-through tube are not connected to each other, and the top opening of the spiral liquid column is connected to the bottom of the lamp-through tube; The spiral liquid column is wound in a clockwise or counterclockwise spiral. The interior of the spiral liquid column is hollow and is used to place an LED light bar. The bottom of the LED light bar is at the bottom of the spiral liquid column, and the top of the LED light bar passes through the spiral liquid column and then extends out from the lamp tube to connect to an external power supply. The bottom of the spiral liquid column is above the liquid surface of the reactor.

2. The spiral falling film photocatalytic sewage treatment experimental device according to claim 1 is characterized in that: The reactor is a cube, and the LED light sheet is attached to the outer surface of at least one side of the reactor, and the LED lamp beads face the inside of the reactor; the top cover of the reactor is detachable, which is convenient for cleaning the inside of the reactor; The top of the water inlet interface is connected to an external sewage source to input sewage into the spiral liquid column.

3. The spiral falling film photocatalytic sewage treatment experimental device according to claim 2 is characterized in that: The side of the water pipe is connected to an external sewage water source or a heat dissipation water pipe; A conical side wall is provided at the bottom of the water pipe, so that the bottom of the water pipe forms a closing end, thereby allowing the sewage in the water pipe to flow down along the outer surface of the spiral liquid column in the form of a falling film.

4. The spiral falling film photocatalytic sewage treatment experimental device according to claim 1 is characterized in that: The LED lamp beads are evenly distributed on the front of the LED light sheet in a matrix shape; The heat dissipation device comprises a first heat dissipation water pipe and a second heat dissipation water pipe. The first heat dissipation water pipe is arranged on the front side of the LED light sheet, and the second heat dissipation water pipe is arranged on the back side. The first heat dissipation water pipe and the second heat dissipation water pipe are respectively coiled around the front side and the back side of the LED light sheet in a serpentine shape. The water inlet of the second heat dissipation water pipe is connected to an external sewage water source, and the water outlet is connected to the water inlet of the first heat dissipation water pipe; the water outlet of the first heat dissipation water pipe is connected to the top of the spiral liquid column, and the sewage flows along the second heat dissipation water pipe and the first heat dissipation water pipe in sequence, which can absorb the heat of the LED lamp sheet to cool the lamp sheet, and at the same time the sewage is preheated and heated.

5. The spiral falling film photocatalytic sewage treatment experimental device according to claim 2 is characterized in that: Two adjacent sides of the reactor are respectively provided with LED light sheets; Reflective sheets are attached to the outer surfaces of the other two sides of the reactor. The front side of the reflective sheet is a bright mirror surface facing the inside of the reactor, reflecting the received light back to the reactor. The back side of the reflective sheet is a light-isolating material to prevent light from passing through.

6. The spiral falling film photocatalytic sewage treatment experimental device according to claim 2 is characterized in that: LED light sheets are laid on the four sides of the reactor, so that light can be propagated, reflected, re-propagated, and re-reflected in all directions in the reactor, thereby improving light energy utilization.

7. The spiral falling film photocatalytic sewage treatment experimental device according to claim 2 is characterized in that: A reflective sheet is attached to the outer surface of the bottom of the reactor, the front side of the reflective sheet faces the inside of the reactor and reflects the received light back to the reactor, and the back side of the reflective sheet is made of light-isolating material to prevent light from passing through.

8. The spiral falling film photocatalytic sewage treatment experimental device according to claim 1 is characterized in that: Several stirring shafts are evenly arranged inside the reactor, and several stirring paddles are evenly arranged on the part of the stirring shaft below the liquid level in the reactor. The stirring paddles are plate-shaped and have reflective sheets on both sides so that the stirring paddles can reflect the received light while rotating.

9. The spiral falling film photocatalytic sewage treatment experimental device according to claim 8 is characterized in that: The stirring paddle is inclined, and the central axis of the stirring paddle is kept vertical; A plurality of protruding edges are evenly arranged on both sides of the stirring paddle. The protruding edges are horizontal or vertical, and the protruding edges protrude in a direction away from the side where they are located.

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