An ultraviolet catalytic oxidation device

Abstract

The utility model discloses a kind of ultraviolet catalytic oxidation devices, the device is equipped with helical flow guide plate extending along the axial direction of device, helical flow guide plate is equipped with the flow guide hole for water to pass through and the hole for ultraviolet lamp tube to pass through, ultraviolet lamp tube passes through the hole of flow guide plate, the hole inner wall is equipped with the reflection layer for reflecting ultraviolet;TiO2 photocatalyst coating is equipped on the flow guide plate.Compared with the ultraviolet catalytic oxidation device (only including multiple ultraviolet lamp tubes extending along the axial direction of cylinder in reaction cavity) in the prior art, the utility model can effectively increase the turbulence degree of water in reaction cavity and most of water flow can flow from the surface of ultraviolet lamp tube, so that the mixing degree of strong oxidizing free radicals and water body increases in short time, most of organic matter in water body can contact strong oxidizing free radicals, so as to improve the degradation effect of free radicals on organic matter.

Description

Technical Field

[0001] This utility model relates to an ultraviolet catalytic oxidation device. Background Technology

[0002] Currently, ultrapure water preparation systems often rely on TOC-UV devices to degrade organic matter in reclaimed water. Conventional low-pressure mercury amalgam lamps can release dual-wavelength ultraviolet light (also known as VUV / UV) at 185nm (VUV) and 254nm (UV), with VUV accounting for approximately 5-10% of the UV light intensity emitted by the low-pressure mercury lamp. Ultraviolet light can activate water molecules to generate strong oxidizing free radicals and the secondary oxidant H2O2. However, existing ultraviolet oxidation devices have low utilization rates of the more energetic 185nm wavelength ultraviolet light during the treatment of reclaimed water. This is because the effective working distance of this wavelength of ultraviolet light is only about 5.6mm, and it is easily absorbed and attenuated by the air and water environment. Therefore, most of the liquid being treated does not come into contact with this wavelength of ultraviolet light. In addition, during the reaction, hydroxyl free radicals are confined to the water flow area near the lamp tube, without sufficient mixing, thus limiting the reaction area for the oxidation of organic matter by free radicals. Therefore, using existing VUV / UV devices to degrade organic matter in reclaimed water presents the problem of excessive energy consumption in order to achieve good removal results (extremely high power is required to remove TOC from 10 μg / L to 1 μg / L). On the other hand, if energy consumption is to be reduced, the degradation effect is not good. Utility Model Content

[0003] Purpose of the utility model: The purpose of this utility model is to provide an ultraviolet catalytic oxidation device that can effectively improve the utilization rate of 185nm wavelength ultraviolet light.

[0004] Technical solution: The ultraviolet catalytic oxidation device of this utility model has a spiral guide plate extending along the axial direction of the device. The spiral guide plate has a guide hole for water supply and a channel for ultraviolet lamp tube to pass through. The ultraviolet lamp tube passes through the channel of the guide plate. The inner wall of the channel is provided with a reflective layer for reflecting ultraviolet rays. The guide plate is provided with a photocatalyst coating.

[0005] The photocatalyst coating is a TiO2 photocatalyst coating. TiO2 photocatalysts can significantly enhance the activity of free radicals in water, thereby improving the degradation capacity and efficiency of organic matter.

[0006] The TiO2 photocatalyst coating on the flow guide plate was prepared by the following method, specifically including the following steps:

[0007] (1) Preparation of TiO2 photocatalyst: 150 parts by mass of nano-anatase phase TiO2 were thoroughly ground to obtain the photocatalyst;

[0008] (2) Preparation of coating solution: The photocatalyst powder is dissolved in the film-forming solution to prepare the coating solution. Polyvinyl alcohol (PVA) is dissolved in a 1% (w / w) aqueous glycerol solution to make the polyvinyl alcohol content 10%. The solution is continuously stirred and heated at 90°C for 1.5 hours to obtain the film-forming solution. 3 parts by weight of photocatalyst powder are added to 100 parts by weight of the film-forming solution. After mixing, the solution is stirred at 1000 r / min for 1 hour to obtain the coating solution.

[0009] (3) Slowly lower the guide plate at a speed of 3 mm / s and immerse it in the coating solution. After it is fully immersed, lift it up at a speed of 6 mm / s. After leaving the coating solution, dry it at 120°C for 40 minutes. After it is fully dried, treat it at 500°C for 3 minutes to complete the coating of the guide plate and the guide plate coated with a photocatalyst coating.

[0010] The reflective layer is a VUV reflective film fixed to the inner wall of the channel, used to reflect ultraviolet light in the wavelength range of 150-200nm; the VUV reflective film includes a metal film and a dielectric film, preferably a hardened coating (hardened aluminum film). The reflective lamp holes effectively enhance ultraviolet light (enhancing VUV illumination through the principle of reflection), significantly improving the utilization efficiency of ultraviolet light and increasing the irradiance in the water.

[0011] The diameter of the channel is slightly larger than the outer diameter of the lamp tube, and the diameter is 2.8 to 3 cm. The channel includes a through hole set on the guide plate, and also includes a channel area extending outward along both sides of the through hole. The length of the channel is 2.8 to 4 cm. The guide holes and channels on the guide plate are arranged in a crisscross pattern, or rather, multiple guide holes are evenly distributed around the periphery of each channel, with a distance of 3-4 mm between the guide holes and adjacent channels. The diameter of the guide holes is 1-1.5 cm, and the shape of the guide holes is circular, fan-shaped, semi-circular, or gourd-shaped. The spiral structure of the guide holes and the guide plate helps to increase the turbulence of the water flowing inside the device (forming eddies, increasing turbulence). This increases the contact between the water flow inside the cavity and the lamp tube and the guide plate, because VUV ultraviolet light in ultraviolet catalytic oxidation is easily attenuated in water, with an effective distance of only 5.6 mm. By setting the distance between the guide holes and adjacent channels to 3-4 mm, most of the water flow can be guided to flow over the surface of the ultraviolet lamp tube, increasing the effective contact between ultraviolet light and the water. On the other hand, it helps the strong oxidizing free radicals generated by ultraviolet activation to mix evenly inside the cavity and fully contact the organic matter in the water, thereby increasing the oxidation effect and improving the oxidation efficiency.

[0012] The baffle is made of stainless steel and is used to change the flow pattern of the water in the reaction chamber.

[0013] The pitch of the spiral guide plate is 16.8 cm, and the height of the spiral guide plate is consistent with the inner diameter of the device.

[0014] Beneficial Effects: Compared with the prior art, this utility model has the following advantages: Compared with the existing ultraviolet catalytic oxidation device (which only includes multiple ultraviolet lamps extending along the cylinder axis in the reaction chamber), this utility model adds a spiral guide plate with a photocatalyst coating in the device, and the ultraviolet lamps pass through the guide plate. The guide holes for water flow are arranged close to the periphery of the ultraviolet lamps. This structure can effectively increase the turbulence of water in the reaction chamber and allow most of the water to flow over the surface of the ultraviolet lamps, thereby increasing the mixing degree of strong oxidizing free radicals with the water in a short time. Most of the organic matter in the water can come into contact with the strong oxidizing free radicals, thereby improving the degradation effect of free radicals on organic matter. At the same time, the lamp holes with reflective function effectively enhance ultraviolet light (enhancing VUV light through the principle of reflection), greatly improving the utilization efficiency of ultraviolet light and increasing the irradiance in the water. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the spiral guide vane.

[0016] Figure 2 A schematic diagram of the structure of an ultraviolet lamp passing through a spiral guide plate;

[0017] Figure 3 This is a schematic diagram of the external structure of the device of this utility model;

[0018] Figure 4 This is a side view of the device of this utility model. Detailed Implementation

[0019] like Figures 1-4 As shown, the ultraviolet catalytic oxidation device of this invention includes a reaction chamber 7 and an inlet 5 and an outlet 6 disposed on the reaction chamber 7. A spiral guide plate 1 extending axially along the reaction chamber is provided inside the reaction chamber 7 (the guide plate is parallel to the axial direction of the reaction chamber cylinder). The total length of the reaction chamber cylinder is 151 cm, and its inner diameter is 36 cm. The pitch of the guide plate 1 is 16.8 cm, and the radius of the spiral blades in the guide plate 1 is the same as the inner radius of the reaction chamber cylinder, which is 18 cm. The spiral guide plate 1 is provided with a guide hole 3 for water supply and a channel 4 for the ultraviolet lamp 2 to pass through. The ultraviolet lamp 2 passes through the channel 4 of the guide plate 1, and a reflective layer for reflecting ultraviolet light is provided on the inner wall of the channel 4. The guide plate 1 is coated with a TiO2 photocatalyst.

[0020] The reflective layer is a VUV reflective film fixed on the inner wall of the channel 4, used to reflect ultraviolet rays in the wavelength range of 150-200nm; the VUV reflective film includes a metal film and a dielectric film, preferably a hardened coating (hardened aluminum film). The aperture of the channel 4 is slightly larger than the outer diameter of the ultraviolet lamp tube 2, and the aperture of the channel 4 is 2.8-3cm; the channel 4 includes a through hole provided on the guide plate 1, and also includes a channel area 41 extending outward along both sides of the through hole, and the length of the channel 4 is 2.8-4cm. Multiple guide holes 3 are evenly distributed around each channel 4 on the guide plate 1. The distance between the guide hole 3 and the adjacent channel 4 is 3-4 mm. The diameter of the guide hole 1 is 1-1.5 cm, and the shape of the guide hole 1 is circular, fan-shaped, semi-circular, or gourd-shaped. The spiral structure of the guide hole 3 and the guide plate 1 helps to increase the turbulence of the water flowing inside the device (forming eddies, increasing turbulence). This increases the contact between the water flow inside the cavity and the lamp tube and the guide plate. Because VUV ultraviolet light in ultraviolet catalytic oxidation is easily attenuated in water, the effective distance is only 5.6 mm. By setting the distance between the guide hole and the adjacent channel to 3-4 mm, most of the water flow can be guided to flow over the surface of the ultraviolet lamp tube, increasing the effective contact between ultraviolet light and water. On the other hand, it helps the strong oxidizing free radicals generated by ultraviolet activation to mix evenly inside the cavity and fully contact the organic matter in the water, thereby increasing the oxidation effect and improving the oxidation efficiency. The guide plate 1 is made of stainless steel and is used to change the flow state of the water in the reaction cavity.

[0021] The reclaimed water, pretreated by the reverse osmosis membrane, enters the ultraviolet catalytic oxidation unit through inlet 5. The TOC value in the reclaimed water is 90 μg / L, and the initial concentration of chloroform is 29.8 μg / L. The hydraulic residence time of the water in the unit is 45 seconds, and the ultraviolet radiation dose is 0.24 kJ / cm². 2 The effluent from the device was tested, and its TOC value was 40.1 μg / L, and the trichloromethane concentration was 13.6 μg / L.

Claims

1. An ultraviolet catalytic oxidation device, characterized in that: The device is provided with a spiral guide plate (1) extending along the axial direction of the device. The spiral guide plate (1) is provided with a guide hole (3) for water supply and a channel (4) for ultraviolet lamp (2) to pass through. The ultraviolet lamp (2) passes through the channel (4) of the guide plate (1). The inner wall of the channel (4) is provided with a reflective layer for reflecting ultraviolet rays. The guide plate (1) is provided with a TiO2 photocatalyst coating.

2. The ultraviolet catalytic oxidation device according to claim 1, characterized in that: The reflective layer is a VUV reflective film fixed on the inner wall of the channel (4) for reflecting ultraviolet rays in the wavelength range of 150-200nm.

3. The ultraviolet catalytic oxidation device according to claim 1, characterized in that: The aperture of the channel (4) is larger than the outer diameter of the ultraviolet lamp tube (2), and the aperture is 2.8 to 3 cm. The channel (4) includes a through hole set on the guide plate (1) and a channel area (41) extending outward along both sides of the through hole. The length of the channel (4) is 2.8 to 4 cm.

4. The ultraviolet catalytic oxidation device according to claim 1, characterized in that: Multiple guide holes (3) are evenly distributed around each channel (4), and the distance between the guide hole (3) and the adjacent channel (4) is 3-4 mm.

5. The ultraviolet catalytic oxidation device according to claim 4, characterized in that: The diameter of the guide hole (3) is 1 to 1.5 cm, and the shape of the guide hole (3) is circular, fan-shaped, semi-circular or gourd-shaped.

6. The ultraviolet catalytic oxidation device according to claim 1, characterized in that: The pitch of the spiral guide plate (1) is 16.8-17cm, and the height of the spiral guide plate (1) is consistent with the inner diameter of the device.

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