JP3648352B2 - Ozone contact reactor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ozone contact reaction tank used for water treatment such as water purification treatment, wastewater treatment, and industrial wastewater treatment. More specifically, ozone is dissolved in water to be treated, and ozone and difficult-to-react substances to be removed. The present invention relates to a double-tube ozone contact reaction tank that performs the oxidation reaction treatment.
[0002]
[Prior art]
FIG. 5 shows a conventional double-tube ozone contact reaction tank, which is described in, for example, US Pat. No. 4,572,821. In the figure, 1 is treated water, 2 is treated water inflow pipe, 3 is ozonized gas, 4 is ozonized gas blowing pipe, 5 is an inner pipe which is the tip of treated water inflow pipe 2, and 6 is inner pipe. 5 is an outer pipe, 7 is treated water oxidized by ozonized gas, 8 is treated water outflow pipe, 9 is exhaust gas discharged by oxidation reaction, 10 is exhaust gas extraction pipe, 11 is from the upper end of outer pipe 5 It is an overflow tank that receives oxidation-treated water from overflowing ozone.
[0003]
This double tube type ozone contact reaction tank is mainly composed of a vertical cylindrical bottomed outer tube 6 and a vertical cylindrical inner tube 5 inserted into the outer tube 6 and opened at the bottom, The space between the inner tube 5 and between the inner tube 5 and the outer tube 6 is an ozone contact reaction tank. The ozonized gas 3 blown from the ozonized gas blowing pipe 4 is sent from an ozone generator. The ozonized gas 3 is blown into the treated water 1 sent from the treated water inflow pipe 2 by natural flow or by a pump or the like through an ozonized gas blowing pipe 4 provided on the upper part of the inner pipe 5. The water 1 to be treated becomes a gas-liquid two-phase flow together with the ozonized gas 3 and descends in the inner pipe 5. During this time, ozone is dissolved in the water 1 to be treated with high efficiency. Then, the ozonized gas 3 that could not be dissolved with the water to be treated 1 rises in the space between the inner tube 5 and the outer tube 6 via the lower end opening of the inner tube 5. Thus, while passing through the space inside the inner tube 5 and the space between the inner tube 5 and the outer tube 6, the substance to be removed, mainly organic matter, is oxidatively decomposed and removed by the dissolved ozone. The treated water 1 flows from the upper part of the outer pipe 1 to the overflow tank 11 and then flows out of the treated water outflow pipe 8 provided in the overflow tank 11. Further, the exhaust gas 9 in the overflow tank 11 is exhausted via the exhaust gas extraction pipe 10.
[0004]
Further, the ozone contact reaction tank is configured so that a necessary residence time can be obtained in order to secure a time required for a reaction between ozone dissolved in water and a substance to be removed. Therefore, when the substance to be removed is a hardly reactive substance, a long stagnation time required for the reaction is required, so that a large internal volume contact tank is formed.
[0005]
In addition, such a double-tube ozone contact reactor is usually circular in cross-section for the convenience of construction and balancing the water level of the process before and after, and most of it is buried in the ground. Has been.
[0006]
In general, the reaction between the object to be removed such as soluble organic matter in the water to be treated and ozone is caused by (1) direct reaction with ozone and (2) OH radical (hydroxyl group, -OH) generated by decomposition of ozone. There are two categories: indirect reactions. The OH radical has a higher oxidation-reduction potential than ozone molecules, and can oxidize a hardly decomposable substance to be removed that cannot be treated by direct reaction with ozone. Therefore, an ozone contact reaction tank provided with auxiliary means for promoting the generation of OH radicals and strengthening the oxidizing power by ozone is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-228296. This ozone contact reaction tank performs an oxidation reaction (ozone reaction) with ozone while irradiating the water to be treated, an ozone reaction while contacting with the catalyst, or an ozone reaction while injecting hydrogen peroxide. This is a so-called accelerated ozone reaction treatment method.
[0007]
[Problems to be solved by the invention]
However, in the double tube type ozone contact reaction tank of FIG. 5, most of the removal of the substance to be removed from the treated water is carried out by direct reaction with ozone. Therefore, when the object to be removed is a hardly decomposable substance, it is necessary to lengthen the residence time of the water to be treated in order to set the oxidation treatment time long. There is a drawback that increases the area and construction cost.
[0008]
On the other hand, the accelerated oxidation treatment method that promotes the generation of OH radicals and strengthens the oxidizing power of ozone has the following problems. First, when ultraviolet rays and ozone are used in combination, the irradiated ultraviolet rays are absorbed by the water to be treated in proportion to the depth (thickness) of the water to be treated. Therefore, the ultraviolet rays that contribute to the generation of OH radicals are a part of the total irradiation amount, and there is a drawback that the generation efficiency of OH radicals is poor.
[0009]
Further, when the catalyst and ozone are used in combination, there is a problem that the efficiency of OH radical generation is low, and the apparatus melt becomes large due to the necessity of extending the contact time between the catalyst and the water to be treated containing ozone. Furthermore, in the case where OH radicals are generated by a photocatalytic reaction using a combination of ultraviolet rays, a catalyst, and ozone, most of the irradiated ultraviolet rays are absorbed by the water to be treated, resulting in poor OH radical production efficiency. This is not economical and has a drawback of increasing the volume of the apparatus.
[0010]
In addition, when hydrogen peroxide and ozone are used in combination, there is a disadvantage that the cost of hydrogen peroxide to be injected is high, and in the domestic water purification treatment, the use of hydrogen peroxide is not currently approved from the viewpoint of safety. Therefore, there is a drawback that the oxidation treatment in the water purification treatment cannot be effectively performed.
[0011]
This invention is made | formed in view of the said subject, and it aims at providing the ozone contact reaction tank using photocatalytic reactions, such as a radiation, an ultraviolet-ray, and a laser beam.
Furthermore, an object of the present invention is to provide an ozone contact reaction tank capable of reducing the size of the ozone contact reaction tank and promoting the ozone contact reaction.
[0012]
[Means for Solving the Problems]
The present invention has been made to achieve the above object, and the invention of claim 1 injects ozonized gas into the water to be treated flowing in from the upper part of the inner pipe, and the treated water together with the ozonized gas. After lowering the inside of the inner pipe, in the process of raising the space between the inner pipe and the outer pipe surrounding the inner pipe, the removal target substance in the treated water is removed by reacting with ozone, and the treated water In an ozone contact reaction tank that flows out from the treated water outflow pipe provided in the overflow tank after overflowing to the overflow tank provided so as to surround the upper part of the outer pipe,
Irradiation device for irradiating the water to be treated that overflows the overflow tank with any one of ultraviolet rays, radiation, or laser light in the process of overflowing the water to be treated from the upper part of the outer pipe to the overflow tank Is provided in the overflow tank. In this invention, when the water to be treated overflowing from the upper end of the outer pipe flows in a thin layer, irradiation of ultraviolet light, radiation, or laser light is performed to reduce the absorption of light by the water to be treated, and the irradiated light Contributes effectively to the generation of OH radicals. The generated OH radical reacts with a hardly reactive substance that could not be removed by ozone dissolved in the water to be treated, and can be decomposed and removed by an oxidation reaction.
[0013]
Moreover, invention of Claim 2 is an ozone contact reaction tank of Claim 1,
In the process of allowing the water to be treated to overflow from the upper part of the outer pipe to the overflow tank, the water to be treated is surrounded by the overflow tank so that the water to be treated flows down the outer wall surface of the outer pipe in a thin layer. The ozone contact reaction tank is characterized in that the outer wall of the outer pipe of the portion is inclined in a divergent or divergent shape from the upper end where the water to be treated overflows. In this invention, by setting it as such a shape, the to-be-processed water which flows into an overflow tank from the upper end of an outer pipe can make the flowing water which flows on the outer wall surface more reliably into a thin layer form, and therefore it was irradiated with ultraviolet rays. The amount of ultraviolet rays absorbed by the water to be treated at the time is reduced, and OH radicals due to ultraviolet rays are efficiently generated.
[0014]
Moreover, invention of Claim 3 is an ozone contact reaction tank of Claim 1 or 2,
The outer wall surface of the outer pipe surrounded by the overflow tank is coated with a catalyst made of at least one of titanium oxide, zinc oxide, tungsten trioxide, nickel salt and cobalt salt, or one or more materials. It is an ozone contact reaction tank. In the present invention, it is possible to generate OH radicals using a photocatalytic reaction. The amount of light absorbed into the water to be treated can be reduced, the amount of light reaching the catalyst surface is increased, the amount of OH radicals generated by the photocatalytic reaction is increased, and the removal treatment by the oxidation reaction by OH radicals is highly efficient. Done.
[0015]
Moreover, invention of Claim 4 is an ozone contact reaction tank of Claim 1, 2, or 3,
In order to expand the irradiation area of ultraviolet rays, radiation, or laser light emitted from the irradiation device provided in the overflow tank, it extends along the outer wall surface of the outer pipe from the upper end of the outer pipe surrounded by the overflow tank. It is an ozone contact reaction tank characterized by giving a drop to the flowing water flowing in a thin layer. In the present invention, since the generation of OH radicals by the photocatalytic reaction can be efficiently performed, the performance of removing hardly reactive substances is further improved.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of an ozone contact reaction tank according to the present invention will be described with reference to the drawings. 1-4 is sectional drawing which shows the outline of this embodiment, and the same code | symbol is provided to the same part.
[0017]
(Embodiment 1)
FIG. 1 shows an embodiment of an ozone contact reaction tank according to the present invention. In the figure, 1 is treated water, 2 is treated water inflow pipe, 3 is ozonized gas, 4 is ozonized gas blowing pipe, 5 is an inner pipe which is the tip of treated water inflow pipe 2, and 6 is inner pipe. 5 is an treated pipe, 7 is treated water, 8 is treated water outflow pipe, 9 is exhaust gas, 10 is exhaust gas take-out pipe, 11a is an overflow tank that surrounds an upper portion of the treated water in the outer pipe 6, and 12 is It is an irradiation device provided on the inner wall of the overflow tank 11a. The irradiation device 12 is disposed in the overflow tank 11a of the double-tube ozone contact reaction tank, and irradiates any one of ultraviolet rays, radiation, and laser light. Since the inner tube 5 and the outer tube 6 are cylindrical, and the irradiation device 12 can easily fill the overflow tank 11a with ultraviolet rays, an ultraviolet irradiation device is preferable.
[0018]
The double-tube ozone contact reaction tank of this embodiment is a vertical cylindrical bottomed outer tube 6, a vertical cylindrical inner tube 5 inserted into the outer tube 6 and opened at the bottom, and an outer tube. 6 is composed of an overflow tank 11 a that surrounds the upper part of 6, an irradiation device 12 provided in the overflow tank 11 a, and an ozonized gas blowing pipe 4 inserted into the inner pipe 2. A space between the inner tube 5 and between the inner tube 5 and the outer tube 6 is an ozone contact reaction tank. The ozonized gas blown from the ozonized gas blowing pipe 4 is sent from an ozone generator (not shown). The ozone generator generates an ozonized gas 3 in which at least a part of oxygen contained in a gas sent from the outside is ozone. The ozonized gas 3 is blown into the treated water 1 sent from the treated water inflow pipe 2 by natural flow or a pump or the like through an ozonized gas blowing pipe 4 provided on the upper part of the inner pipe 5. The water 1 to be treated becomes a gas-liquid two-phase flow together with the ozonized gas 3 and descends in the inner pipe 5. During this time, ozone is dissolved in the water 1 to be treated with high efficiency. Then, the ozonized gas 3 that could not be dissolved with the water to be treated 1 rises in the space between the inner tube 5 and the outer tube 6 via the lower end opening of the inner tube 5. Oxidized water that overflows from the upper end of the outer tube 6 is irradiated with ultraviolet rays from the irradiation device 12 to generate OH radicals in the oxidized water, and oxidize hardly reactive substances by oxidizing the OH radicals. And then disassembled and removed. Oxidized water overflowing from the upper end of the outer pipe 6 falls into the overflow tank 11a in a thin layer, and the drop L is maintained to such an extent that the flowing water can be sufficiently irradiated with ultraviolet rays. The irradiation device 12 irradiates the thin laminar flowing water with ultraviolet rays to generate OH radicals and rapidly react with the hardly reactive substance in the water to be treated. The object to be removed can be oxidatively decomposed. And the to-be-processed water 1 is made to flow into the overflow tank 11a from the upper part of the outer tube | pipe 6, and flows out out of the tank from the treated water outflow pipe 8 provided in the overflow tank 11a. Further, the exhaust gas 9 in the overflow tank 11 a is exhausted through the exhaust gas extraction pipe 10.
[0019]
As described above, in the present embodiment, ozone dissolved in the water to be treated while the water to be treated in which the ozonized gas is dissolved passes through the inner pipe 5 and the space between the inner pipe 5 and the outer pipe 6. The removal target substance centering on the organic matter is decomposed and removed by the oxidation reaction by the generated OH radical. Further, ultraviolet light or the like is applied to the thin-layer flowing water that flows from the upper end portion of the outer pipe 6 to the overflow tank 11b to generate OH radicals and decompose the hardly-reactive substance by an oxidation reaction. In this way, after the object to be removed in the water to be treated is decomposed by the oxidation reaction treatment using ozone, the ultraviolet ray is irradiated from the irradiation device 12 to the overflowing thin layer water flow, so that the ultraviolet water to be treated is treated. Since the absorption amount to 1 can be reduced, it is possible to efficiently remove the hardly reactive substance by the oxidizing action by the OH radical. Of course, in the oxidation reaction treatment with ozone, it is obvious that the water to be treated is sterilized, decolorized, deodorized, or iron removed, manganese removed, etc. in the water to be treated.
[0020]
(Embodiment 2)
FIG. 2 is a sectional view showing an outline of another embodiment of the present invention. In the embodiment shown in the figure, in addition to the embodiment shown in FIG. 1, a tapered outer wall 13 is formed on the outer wall of the outer pipe 6 surrounded by the overflow tank 11b. ing. The treated water 1 that overflows from the upper end of the outer pipe 6 flows down into a thin layer on the surface of the tapered outer wall 13 that is inclined in a divergent manner. Therefore, by irradiating this thin laminar flowing water with ultraviolet rays from the irradiation device 12, OH radicals can be efficiently generated in the water to be treated, with the ultraviolet rays being hardly absorbed by the water to be treated. Due to the oxidizing action by the OH radicals generated by the ultraviolet irradiation, it is possible to efficiently remove the hardly reactive substance.
[0021]
(Embodiment 3)
FIG. 3 is a cross-sectional view showing an outline of another embodiment of the present invention. In the embodiment shown in the figure, in addition to the embodiment shown in FIG. 2, a catalyst layer 14 is provided on the surface of the tapered outer wall 13 inclined in a divergent shape from the upper end of the outer pipe 6 surrounded by the overflow tank 11 b. Yes. The catalyst layer 14 is formed of at least one catalyst such as titanium oxide, zinc oxide, tungsten trioxide, nickel salt, and cobalt salt, a mixture of those, or a material mixed with one or more of them. . The formation of the catalyst layer 14 on the surface of the tapered outer wall 13 promotes the oxidation reaction treatment between ozone and OH radicals and the hardly reactive substance in the water to be treated. Further, the thin layered water flow flowing from the upper end opening of the outer pipe 6 through the surface of the catalyst layer 14 to the overflow tank 11b is irradiated with ultraviolet rays from the irradiation device 12 provided in the overflow tank 11b. Thus, the amount of ultraviolet rays absorbed into the water to be treated 1 is reduced, OH radicals are efficiently generated, and the decomposition and removal treatment of difficult-to-react substances by OH radicals utilizing the photocatalytic reaction is performed efficiently. The catalyst layer 14 is provided with a required drop L in order to obtain sufficient contact with the water to be treated. Also in the embodiment of FIG. 1, the same effect can be expected by forming the catalyst layer 14 on the outer wall surface of the outer tube 6.
[0022]
(Embodiment 4)
FIG. 4 is a cross-sectional view showing an outline of another embodiment of the present invention. In the embodiment shown in the figure, a tapered outer wall 6a is formed in which the upper end portion 6a of the outer tube 6 is inclined from the upper end. Since other shapes are the same as those of the embodiment of FIG. 1, detailed description thereof is omitted. The treated water that overflows the outer wall 6a of the outer pipe 6 flows down as a stable thin-layered water stream on the outer wall 6a of the tapered outer pipe 6 that is inclined in a divergent shape. By irradiating ultraviolet rays from the irradiation device 12, absorption of ultraviolet rays by the water to be treated can be suppressed, and OH radicals can be efficiently generated. Therefore, separation and removal by oxidation treatment of hardly reactive substances in the water to be treated Processing performance can be improved.
[0023]
Of course, the irradiation device 12 in the overflow layers 11a to 11c may be irradiated with radiation such as X-rays or laser light in addition to ultraviolet rays. For example, the laser tube of the laser irradiation device is in the overflow layers 11a to 11c. The drive device, the control device, and the like may be provided outside the irradiation device 12. The same applies to an irradiation apparatus that irradiates ultraviolet rays and radiation.
[0024]
【The invention's effect】
As described above, according to the present invention, the water to be treated overflowing from the upper end of the outer pipe flows down into a thin layer, and the water to be treated is irradiated with ultraviolet rays or the like to generate OH radicals in the water to be treated. There exists an advantage which can perform efficiently the removal process of a hard-to-react substance by the oxidation reaction by OH radical with respect to the oxidation process water which produced | generated efficiently and was ozone-treated.
[0025]
In addition, the water to be treated that overflows from the upper end of the outer pipe is made into a thin layer, and the required drop is given, so that the water to be treated and the catalyst layer are sufficiently contacted, and the photocatalytic reaction causes a difficult reaction in the water to be treated. There is an advantage that the decomposition and removal treatment by the oxidation reaction of the active substance can be effectively performed.
[0026]
In addition, since the decomposition and removal treatment by the oxidation reaction of the difficult-to-react substance of the water to be treated is performed with high efficiency, there is an advantage that the size of the conventional ozone contact reaction tank can be reduced, especially the shape in the depth direction can be reduced. There is an advantage that construction costs can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of an ozone contact reaction tank according to the present invention.
FIG. 2 is a cross-sectional view showing another embodiment of the ozone contact reaction tank according to the present invention.
FIG. 3 is a cross-sectional view showing another embodiment of the ozone contact reaction tank according to the present invention.
FIG. 4 is a cross-sectional view showing another embodiment of the ozone contact reaction tank according to the present invention.
FIG. 5 is a perspective view showing an example of a conventional ozone contact reaction tank.
[Explanation of symbols]
2 treated water inflow pipe 4 ozonized gas blowing pipe 5 inner pipe 6 outer pipe 6a upper end 8 treated water outflow pipe 10 exhaust gas take-out pipes 11a to 11c overflow tank 12 irradiation device 13 outer wall 14 catalyst layer

Claims (4)

Ozonized gas is blown into the water to be treated flowing from the upper part of the inner pipe, and the treated water is lowered together with the ozonized gas in the inner pipe, and then rises in the space between the inner pipe and the outer pipe surrounding it. In the process of removing the substance to be removed in the treated water by reacting with ozone and removing the treated water to an overflow tank provided so as to surround the upper part of the outer pipe, In the ozone contact reaction tank that flows out from the treated water outflow pipe provided in the overflow tank,
Irradiation device for irradiating the water to be treated that overflows the overflow tank with any one of ultraviolet rays, radiation, or laser light in the process of overflowing the water to be treated from the upper part of the outer pipe to the overflow tank Is provided in the overflow tank. In the ozone contact reaction tank according to claim 1,
In the process of allowing the water to be treated to overflow from the upper part of the outer pipe to the overflow tank, the water to be treated was surrounded by the overflow tank so that the water to be treated flows down the outer wall surface of the outer pipe in a thin layer. An ozone contact reaction tank characterized in that the outer wall of the outer pipe of the portion is inclined in a divergent or divergent shape from the upper end where the treated water overflows. In the ozone contact reaction tank according to claim 1 or 2,
The outer wall surface of the outer pipe surrounded by the overflow tank is coated with a catalyst made of at least one of titanium oxide, zinc oxide, tungsten trioxide, nickel salt and cobalt salt, or one or more materials. Ozone contact reaction tank. In the ozone contact reaction tank according to claim 1, 2, or 3, in order to expand the irradiation area of ultraviolet rays, radiation or laser light irradiated from an irradiation device provided in the overflow tank, An ozone contact reaction tank characterized in that a drop is given to flowing water flowing in a thin layer along the outer wall surface of the outer pipe from the upper end of the enclosed outer pipe.

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