JP2018122044A - Air bubble stirring type ultraviolet irradiation method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide ultraviolet irradiation method and device capable of irradiating ultraviolet irradiation amount needed with corresponding to ultraviolet permeability of a stock solution.SOLUTION: In an ultraviolet irradiation method for flowing a stock solution 3 which is a target for ultraviolet irradiation through a spiral tube 22 having ultraviolet permeability and irradiating ultraviolet to the stock solution from an outside of spiral of the spiral tube 22, a gas is blown to the stock solution 3. The gas is at least one of gas selected from air, oxygen gas including ozone, carbonic acid gas, inert gas or specific gas suitable for generating, decomposing or chemically changing a target material by an optical chemical reaction on a specific material in the stock solution. Further it is preferable that a fine photocatalyst is added to the stock solution in the case that the optical chemical reaction is utilized.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bubble stirring type ultraviolet irradiation method and apparatus, and in particular, a technique for irradiating ultraviolet rays to a stock solution that is a liquid to be treated to kill or inactivate pathogens in the stock solution, or ultraviolet rays to the stock solution. UV irradiation method and apparatus used in photochemical reaction technology for modifying specific components in the stock solution by photochemical reaction, such as technology for generating, synthesizing, isomerizing, oxidizing, polymerizing, or decomposing target components .

  Ultraviolet irradiation devices include, for example, beverage liquids and foods containing pathogens such as bacteria (organisms such as bacteria and viruses) that may impair the health of animals including humans, additives added to them (hereinafter referred to as liquid foods) Etc.) is used to detoxify pathogens contained in liquid foods by irradiating with ultraviolet rays. In addition, ultraviolet light is irradiated to liquid foods, etc., to generate useful components (for example, vitamins, etc.) by photochemical reaction of specific components contained in liquid foods, etc., or to generate or chemically change components that affect taste and odor Used to make Furthermore, the photochemical reaction technique includes techniques such as synthesis, isomerization, oxidation, polymerization, or decomposition of a specific component by ultraviolet rays.

  In addition, there has been proposed a technique that uses a combination of pathogen detoxification techniques and photochemical reaction techniques without distinguishing them. For example, pathogens contained in water (use water, clean water, sewage, reclaimed water, drainage, etc.) are rendered harmless by ultraviolet irradiation. Furthermore, in order to decompose and detoxify harmful substances by photochemical reaction by irradiating specific components such as organic substances (hazardous substances) contained in the water with ultraviolet rays, ozone is injected into the water. It has been proposed to make the water harmless by promoting the photochemical reaction.

  By the way, in the technology for detoxifying pathogens, for example, in the case of liquid foods including slurries, those that are not suitable for treatment with chemicals such as chlorine and ozone, or pathogens that cannot be detoxified at a predetermined heating temperature, For example, some contain spores. In particular, when a liquid food or the like is heated to a predetermined temperature or higher, the taste, fragrance, and flavor are altered and the value of the liquid food or the like is impaired.

  On the other hand, the pathogen detoxification treatment by ultraviolet irradiation does not basically detoxify the pathogen by heating liquid food or the like, and therefore generally has lower equipment costs and maintenance costs than heating. There is an advantage. However, the pathogen detoxification treatment by ultraviolet irradiation is difficult in principle for all the undiluted solutions to receive the ultraviolet irradiation evenly in consideration of the whole undiluted solution to be treated. That is, considering the whole stock solution divided into microfluidic soot (elements), depending on the flow path of the microfluidic soot in the flow path of the device through which the stock solution is circulated, the difference in the amount of ultraviolet radiation irradiated to the flow route, etc. The amount of UV irradiation received by each microfluidic cage varies.

  In general, when the ultraviolet irradiation amount of each microfluidic bottle in the whole stock solution is collected and statistically processed, the ultraviolet irradiation amount of all the microfluidic bottles is distributed (for example, a normal distribution). For example, as the ultraviolet ray transmittance of the stock solution decreases, the ultraviolet ray irradiation amount distribution width (usually expressed by a half-value width) increases. Therefore, if the distribution range of the UV irradiation amount is large, the amount of microfluids with a low UV irradiation amount increases, and the whole undiluted solution discharged from the UV irradiation device is not subjected to the predetermined UV irradiation processing. It is inconvenient to be discharged at Therefore, it is necessary to design the performance of the ultraviolet irradiation method and apparatus so as to obtain an ultraviolet irradiation distribution that can be processed with a predetermined ultraviolet irradiation.

  Here, the technical meaning of the UV irradiation amount distribution will be further described. When irradiating ultraviolet light by continuously passing the stock solution through the flow path of the ultraviolet irradiation device, the ultraviolet irradiation amount received by the stock solution is the ultraviolet intensity at the position in the flow path through which the stock solution passes (mainly the distance from the ultraviolet light source), The time varies depending on the time (residence time) in which the undiluted solution receives ultraviolet rays having the ultraviolet intensity. For example, in order to dynamically analyze the flow of the stock solution in the flow path of the ultraviolet irradiation device, a technique such as a well-known finite element method is used to set a microfluid mass in the flow of the stock solution as an analysis element. The amount of ultraviolet irradiation received by the microfluidic mass correlates with the product of the ultraviolet intensity in the microchannel through which the microfluidic mass circulates and the micro residence time, which is the time for passing through the microchannel. Therefore, based on the ultraviolet intensity and the minute residence time in the microchannel through which the stock solution flows from the inflow to the outflow of the ultraviolet irradiation device, the integrated value of the ultraviolet irradiation amount is obtained for each microfluidic mass and each microfluidic fluid is obtained. The amount of UV irradiation is obtained. As a result, a set of ultraviolet irradiation doses received by each microfluidic mass of the whole stock solution is obtained, and by this, the dispersion of the ultraviolet irradiation doses of each microfluidic mass of the whole stock solution is obtained statistically, thereby obtaining the microfluidic mass of the whole stock solution. You can see the distribution of UV irradiation amount.

  For example, when the stock solution has a high UV transmittance, the UV light is hardly absorbed by the stock solution, so the UV intensity received by the microfluid mass regardless of the position of the microchannel (distance from the UV light source) through which the stock solution passes is Almost uniform. For this reason, the difference in ultraviolet intensity received by the microfluidic mass is relatively small regardless of the position of the microchannel, so the width of the ultraviolet irradiation distribution of the microfluidic mass of the entire stock solution is relatively narrow. Thereby, it turns out that the ultraviolet-ray is uniformly irradiated to the whole undiluted | stock solution.

  On the other hand, when the ultraviolet transmittance of the stock solution is low, the ultraviolet light is largely absorbed by the stock solution. Therefore, the intensity of the received ultraviolet light increases exponentially as the microfluid mass passes through a position closer to the ultraviolet light source. On the contrary, in the microfluid mass that circulates in a position far from the ultraviolet light source, the ultraviolet light is absorbed by other microfluids in the optical path on the way, so that the intensity of the received ultraviolet light decreases exponentially. Therefore, the width of the UV irradiation amount distribution of the whole stock solution is wider than that of a stock solution having a high UV transmittance. As a result, the amount of ultraviolet irradiation with respect to the whole stock solution is not uniform, and a predetermined amount of ultraviolet light irradiation is not irradiated, and the whole stock solution may not be able to obtain an ultraviolet treatment effect such as a detoxification rate.

  Here, assuming that treatment effects such as a predetermined detoxification rate and degradation rate of the pathogen as a whole stock solution are obtained, if the range of the UV irradiation dose distribution is wide, the predetermined UV irradiation is applied even in the low dose portion. It is necessary to secure the amount. Therefore, it is necessary to increase the ultraviolet irradiation amount of the whole stock solution by increasing the residence time or increasing the number of UV light sources and the UV intensity as the UV transmittance of the stock solution is low.

  However, simply increasing the number of UV light sources and the UV intensity will cause excessive UV irradiation in the high irradiation part (especially peak part) of the UV irradiation distribution, resulting in liquid foods such as taste, aroma and flavor. It is a cause of deteriorating value and lowering cost performance. Therefore, there is a demand for technical development that improves the ultraviolet irradiation distribution without increasing the ultraviolet irradiation amount of the high irradiation portion (particularly the peak portion). For example, clean water or the like generally has a high ultraviolet light transmittance, so that its cost performance is sufficiently high. Therefore, a technique of sterilization or detoxification by ultraviolet irradiation is generally widely used. However, stock solutions such as liquid foods are widely distributed, such as those with extremely low to moderate UV transmittance, so that the UV irradiation dose distribution is improved for application to sterilization, detoxification, decomposition, etc. Improvement and ingenuity of technology related to ultraviolet irradiation are required.

  On the other hand, in the case of an ultraviolet irradiation device used for photochemical reaction, the stock solution to be subjected to the photochemical reaction treatment is widely distributed from extremely low to medium ultraviolet transmittance. There is a demand for improvements and ingenuity related to ultraviolet irradiation, such as improving the dose distribution.

  For example, Patent Document 1 proposes an ultraviolet irradiation device formed by reducing the diameter of an ultraviolet ray transmitting spiral tube through which a stock solution for irradiating ultraviolet rays is distributed and winding it in a spiral shape. According to this, since the diameter of the spiral tube is thin, it is possible to secure a high ultraviolet irradiation amount to be irradiated to the stock solution in the central portion of the spiral tube even with a stock solution having a low ultraviolet transmittance. Thereby, the ultraviolet irradiation amount distribution can be improved, that is, the width of the ultraviolet irradiation amount distribution can be narrowed. In addition, while flowing through the spiral tube, the stock solution is stirred by the action of centrifugal force or the like by the spiral flow, and the stirring action circulates in the vicinity of the wall surface of the spiral tube irradiated with the ultraviolet light even with a stock solution having a low ultraviolet transmittance. Probability increases. As a result, the width of the ultraviolet ray irradiation amount distribution can be narrowed, and as a result, the ultraviolet ray irradiation amount of the whole stock solution can be increased.

JP 2013-158717 A

  By the way, the ultraviolet irradiation device described in Patent Document 1 can increase the amount of ultraviolet irradiation even in a stock solution having a low ultraviolet transmittance, but further increases the amount of ultraviolet irradiation with respect to a stock solution having a low ultraviolet transmittance. At the same time, it is desired to narrow the width of the UV irradiation distribution. That is, the stock solution to be detoxified or subjected to photochemical reaction is widely distributed, such as one having an extremely low UV transmittance and a medium one. In other words, the ultraviolet light transmittance (or ultraviolet light absorption rate) varies depending on the stock solution itself or the suspended matter contained in the stock solution, the difference in concentration, and the like. Accordingly, there is a need for an ultraviolet irradiation method and apparatus that can further improve the ultraviolet irradiation distribution in accordance with the ultraviolet transmittance of these undiluted solutions and can irradiate the entire range of ultraviolet irradiation amounts within a predetermined range.

By the way, in the above description, based on the ultraviolet transmittance of the stock solution, the term UV irradiation amount applied to the stock solution has been described. However, in the technical field according to the present invention, a specific substance or gas (gas) in the stock solution, etc. In some cases, the term “absorbed amount of ultraviolet rays” is used. In addition, the term ultraviolet ray distribution corresponding to this is also used. In the case of a technique for detoxifying a pathogen in a stock solution, the evaluation is generally performed by an ultraviolet irradiation amount per unit surface area of a microfluidic tub (for example, mj / cm ^{2 in} terms of UV output of an ultraviolet lamp). On the other hand, in the case of a photochemical reaction technique for a specific substance in a stock solution, it is common to evaluate the UV absorption amount per unit volume of a microfluidic soot (for example, mj / cm ^{3 in} terms of UV output of an ultraviolet lamp). is there.

  However, even in the case of pathogen detoxification technology, if the UV transmittance of the stock solution is low, the amount of UV light received by the smiley fluid bottle far from the light source is absorbed by the microfluid bottle in the middle. This can be explained more appropriately.

The ultraviolet transmittance UVT is expressed by the following equation (1) as a function of the ultraviolet absorbance α of the stock solution to be irradiated with ultraviolet rays.
UVT = 10 ^-α (1)
The absorbance α is a value indicating the degree to which ultraviolet rays are absorbed when passing through the undiluted solution, and as is clear from the equation (1), as the absorbance α increases, the ultraviolet transmittance UVT decreases exponentially. . That is, since the ultraviolet transmittance has a relationship between the front and back of the ultraviolet absorbance, the concept is substantially the same in the ultraviolet irradiation technology. Therefore, in the case of pathogen detoxification technology, the pathogen is killed or inactivated by irradiating the pathogen with germs, etc., but the microfluidic sputum depends on the UV absorbance of the stock solution according to the distance from the light source. The amount of ultraviolet irradiation applied to the surface decreases. Therefore, it is preferable to evaluate the amount of ultraviolet irradiation that varies depending on the distance from the light source in consideration of the ultraviolet absorbance of the stock solution. In particular, the present invention is a case where a raw solution (including slurry) having a low ultraviolet transmittance, that is, a high ultraviolet absorbance is used as a processing target, because ultraviolet rays are absorbed by the raw solution, and thus is not applied to the photochemical reaction technique. However, it is necessary to take into account the ultraviolet absorbance of the stock solution.

  Therefore, in the present specification, the present invention will be described using the term ultraviolet absorption amount instead of ultraviolet transmittance. Further, since the ultraviolet absorption distribution is substantially synonymous with the ultraviolet irradiation distribution when the ultraviolet absorbance is taken into account, the ultraviolet absorption distribution will be described using the term ultraviolet irradiation distribution.

  The problem to be solved by the present invention is that when the stock solution to be irradiated with ultraviolet rays is circulated through an ultraviolet light permeable spiral tube and irradiated with ultraviolet rays, the amount of UV irradiation depends on the UV absorbance (or UV transmittance) of the stock solution. An object of the present invention is to provide an ultraviolet irradiation method and apparatus capable of further improving the distribution and capable of irradiating the entire stock solution with a predetermined ultraviolet irradiation amount.

  In order to solve the above-described problems, the ultraviolet irradiation method of the present invention distributes a stock solution to be irradiated with ultraviolet rays through a spiral tube having ultraviolet transparency wound spirally, and at least the inner and outer sides of the spiral of the spiral tube. In the ultraviolet irradiation method of irradiating the stock solution with ultraviolet light from one side, a gas is blown into the stock solution.

  Thus, when gas is blown into the stock solution, bubbles are formed in the liquid by the blown gas. Due to the bubbles, the stock solution becomes a gas-liquid mixed phase flow. Due to the stirring action of the gas-liquid mixed phase flow, the flow path of the microfluids flowing through the spiral tube changes variously. Therefore, it is possible to irradiate the stock solution with ultraviolet rays with high efficiency by keeping the amount of ultraviolet rays received by the microfluidic soot within a relatively uniform range. As a result, by adjusting the stirring action by bubbles corresponding to the UV absorbance of the stock solution, the width of the UV dose distribution can be further narrowed, and the UV dose to the stock solution can be increased with high efficiency and the whole stock solution Can be irradiated with a predetermined ultraviolet irradiation amount.

  In addition, when the stock solution circulates in a spiral tube in which the stock solution is spirally wound, in addition to the stirring action of the stock solution by the spiral flow, the stock solution is effectively stirred by the stirring action of bubbles, so that Since the width (half width) is improved in the direction of further narrowing, it is possible to increase the amount of ultraviolet irradiation. Furthermore, by adjusting the parameters of bubbles to be blown (described later), the amount of ultraviolet irradiation can be adjusted with high efficiency corresponding to the ultraviolet absorbance of the stock solution. That is, stirring the undiluted solution in the spiral tube is a major factor in increasing the UV irradiation amount by narrowing the UV irradiation amount distribution or UV absorption amount distribution.

  Here, the stirring effect | action of the undiluted | stock solution by the bubble in this invention is demonstrated concretely. In general, an undiluted solution in an extremely thin region (hereinafter referred to as an ultrathin region) in contact with the inner wall of the spiral tube is effectively irradiated with ultraviolet rays through the spiral tube having high ultraviolet transmittance. However, if the ultraviolet light absorbance of the stock solution is high, UV light may not reach the stock solution flowing on the tube center side in the extremely thin region. Moreover, the flow of the undiluted solution in contact with the inner wall of the tube is a stable flow in contact with the inner wall of the tube, and is difficult to mix with the undiluted solution flowing on the center side of the tube. In view of such a phenomenon, the present invention blows bubbles into the stock solution flowing through the spiral tube, and peels off the stock layer in the ultrathin region that flows stably in contact with the inner wall of the spiral tube from the inner wall of the spiral tube. The undiluted solution layer in the ultrathin region is replaced and the undiluted solution is stirred. That is, the stable stock solution layer on the inner wall of the spiral tube is peeled off by the bubbles, and a new stock solution layer is formed on the inner wall after the peeling. In this way, the ultraviolet rays are irradiated to the new stock solution layer formed by replacement, and the ultraviolet ray irradiation rate with respect to the stock solution is improved as a whole, and the ultraviolet ray irradiation amount distribution can be improved. Furthermore, since the stirring efficiency of the stock solution is enhanced by the behavior of bubbles due to buoyancy in the stock solution, the UV irradiation dose distribution can be further improved.

  Furthermore, in addition to the stirring action described above, another action for increasing the amount of ultraviolet irradiation by bubbles will be described. Since bubbles have a much higher ultraviolet transmittance than the stock solution, the ultraviolet rays irradiated to the bubbles near the inner wall of the spiral tube are diffusely reflected in the bubbles and irradiated to the stock solution in contact with the bubbles. This means that the irradiation area of the irradiated stock solution is increased, and the amount of ultraviolet irradiation with respect to the stock solution can be increased.

  Thus, according to the present invention, the substantial ultraviolet absorbance of the stock solution can be significantly reduced by the combined synergistic action of the bubbles formed by flowing the stock solution into the spiral tube and blowing the gas into the stock solution. Compared with the conventional method in which no gas is blown, the amount of ultraviolet irradiation with respect to the stock solution can be remarkably increased. In addition, by adjusting various parameters of bubbles (for example, the amount (volume ratio) of bubbles to the stock solution, the particle size of the bubbles, the type of gas, etc.) according to the difference in the UV absorbance of the stock solution, different UV absorbance Even for this undiluted solution, high-efficiency ultraviolet irradiation can be performed by narrowing the width of the ultraviolet irradiation amount distribution. In particular, it is possible to adjust to the necessary UV irradiation amount by reducing excessive irradiation and under irradiation as much as possible in accordance with the detoxification target or photochemical reaction target stock solution to be irradiated.

  Further, the processing liquid that has been distributed through the spiral tube and processed by ultraviolet irradiation can be discharged into a processing liquid tank at atmospheric pressure. At this time, the gas (bubbles) blown into the stock solution is naturally degassed from the treatment solution according to the differential pressure between the pressure of the stock solution and the atmospheric pressure. Note that, when the differential pressure is large, degassing is performed rapidly, so that the processing liquid in the processing liquid tank may swell violently. In this case, it is preferable that the treatment liquid tank is sealed and the deaeration speed is adjusted by the pressure adjustment valve. On the other hand, when natural deaeration takes time, it is preferable to deaerate by vacuuming as necessary.

  Here, the gas to be blown is suitable for generating a target substance by photochemical reaction of a specific substance in air, oxygen gas (including ozone), carbon dioxide gas, inert gas (for example, nitrogen gas), or a stock solution. At least one selected from the specific gas. That is, it is preferable to select one or more kinds of gases suitable for the purpose of irradiation with ultraviolet rays. In particular, it is desirable that the gas be selected so as not to adversely affect the quality degradation or photochemical reaction of the liquid food as the stock solution. For example, in the case of a gas that is difficult to dissolve in the stock solution, a liquid food that is easily oxidized, a gas that is difficult to oxidize, such as carbon dioxide, or an inert gas such as nitrogen gas is preferred. Furthermore, when applying to a photochemical reaction, it is natural to select a gas suitable for the photochemical reaction.

  For example, ozone is injected into the ultraviolet irradiation device with an ejector or the like, and is circulated in the spiral tube 22 as a gas-liquid mixed phase flow. Thereby, the short path | pass by the buoyancy of an ozone bubble can be prevented. Further, due to the combined action of the centrifugal force and inertial force of the gas-liquid mixed phase flow and the buoyancy of the ozone bubbles, ozone is dissolved from the ozone bubbles into the liquid phase with high efficiency, and the dissolved ozone concentration can be increased. In this way, it is possible to promote the reaction of oxidatively decomposing dissolved organic compounds in water by generating ultraviolet radicals by irradiating dissolved ozone with ultraviolet rays to generate hydroxy radicals.

  In order to promote the photochemical reaction, it is preferable to add photocatalyst particles having a fine particle size that can be filtered with a filter membrane to the stock solution. The production reaction of the target substance (target component) accompanied by the photochemical reaction and the decomposition reaction of the harmful component can be effectively promoted.

  An ultraviolet irradiation apparatus for carrying out the ultraviolet irradiation method of the present invention includes a stock solution supply pipe for supplying a stock solution that is a liquid to be treated, a gas blowing device for blowing gas into the stock solution flowing through the stock solution supply pipe, and the gas A spiral tube wound in a spiral shape through which a stock solution containing gas bubbles blown into the stock solution from a blowing device is circulated, and disposed on at least one of the inside and the outside of the spiral of the spiral tube A bubble stirring type ultraviolet irradiation device comprising an ultraviolet light source is proposed.

  According to this, the above-described bubble stirring type ultraviolet irradiation method can be easily carried out, and as described above, the width of the ultraviolet ray irradiation distribution is reduced by the combined action of bubbles formed by blowing gas into the stock solution. Since the amount of ultraviolet irradiation with respect to the stock solution can be increased by narrowing, the parameters such as the amount of gas blown into the stock solution can be adjusted to adjust to the necessary amount of ultraviolet irradiation.

  According to the present invention, when an undiluted solution to be irradiated with ultraviolet rays is circulated through an ultraviolet light permeable spiral tube and irradiated with ultraviolet rays, the UV irradiation amount distribution is further improved according to the ultraviolet absorbance (or ultraviolet transmittance) of the undiluted solution. In addition, it is possible to provide an ultraviolet irradiation method and apparatus capable of irradiating the entire stock solution with a predetermined ultraviolet irradiation amount.

It is a system configuration | structure figure of the ultraviolet irradiation device suitable for implementing the bubble stirring type ultraviolet irradiation method of one Embodiment of this invention. It is a block diagram of the ultraviolet irradiation device of one embodiment applied to the bubble stirring type ultraviolet irradiation device of the present invention. It is the arrow line view seen from the arrow III-III of FIG.

  Hereinafter, the present invention will be described based on embodiments.

  As shown in FIG. 1, the bubble stirring type ultraviolet irradiation device of one embodiment of the present invention is mainly configured by the ultraviolet irradiation device 1 shown in FIGS. The stock solution tank 2 stores a stock solution that is a liquid to be treated. The stock solution tank 2 may be omitted, and the stock solution 3 may be directly supplied from a supply source (not shown). The stock solution 3 of the present embodiment is a slurry of additives such as food having high viscosity and extremely low ultraviolet transmittance, that is, high ultraviolet absorbance. The stock solution 3 in the stock solution tank 2 is stirred by a stirrer 4 in order to prevent precipitation of suspended substances in the slurry. The stock solution 3 is not limited to this, and can be applied to various liquid foods. For example, useful ingredients (for example, vitamins, etc.) can be obtained by a technique for detoxifying pathogens contained in liquid foods by irradiating them with ultraviolet rays, or by photochemical reaction of specific ingredients contained in liquid foods by irradiating liquid foods with ultraviolet rays. ), Or a technique for changing or decomposing components that affect the taste and odor. Further, it can be applied to an ultraviolet irradiation device including decomposing and detoxifying harmful substances in water (water, sewage, irrigation water, reclaimed water, drainage, etc.) by a photochemical reaction.

  The stock solution 3 in the stock solution tank 2 is sucked by a pump 6 through a suction tube 5 and supplied to the ultraviolet irradiation device 1 through a stock solution supply tube 7. The processing liquid that has been distributed through the ultraviolet irradiation device 1 and irradiated with ultraviolet light is discharged to the processing liquid tank 9 through the liquid feeding pipe 8. The treatment liquid tank 9 is formed in a sealed structure and is opened to the atmosphere via the pressure adjustment valve 10.

  The stock solution supply pipe 7 is provided with a gas blowing device 11 in the middle. The gas blowing device 11 divides a part of the stock solution flowing in the stock solution supply pipe 7 from the stock solution supply pipe 7 and returns the original stock solution supply pipe 7 to the original stock solution supply pipe 7 and the bypass pipe 12 to the valves 13a and 13b. The ejector 14 is provided with being sandwiched, and a gas supply source 16 connected via an air supply pipe 15 that supplies gas to the suction port of the ejector 14. In addition, the ejector 14 is a well-known thing, and a basic structure is formed by having the aperture | diaphragm | squeeze part through which the undiluted | stock solution 3 distribute | circulates, and the suction opening provided in the inner surface of the aperture | diaphragm | squeeze part. The other gas is sucked in from the suction port by the negative pressure generated in the throttle portion of the ejector 14 by the flow of the stock solution 3. In addition, the air supply pipe 15 is provided with an adjustment valve 17 that adjusts the gas blowing amount. In the present embodiment, as an example of detoxifying the pathogen contained in the slurry of the food additive of the stock solution 3, an example in which air is used for the gas will be described. However, the present invention is not limited to this, and the air is used as the gas. In addition, oxygen gas (including ozone), carbon dioxide gas, inert gas containing nitrogen gas, and specific substances in undiluted solution 3 are selected from specific gases suitable for generating target substances by photochemical reaction At least one gas can be used.

  A flow rate adjusting valve 18 is provided on the downstream side of the bypass pipe 12 of the stock solution supply pipe 7 to adjust the flow rate of the stock solution 3 supplied to the ultraviolet irradiation device 1 and the gas-liquid mixed phase. Further, the stock solution supply pipe 7 between the flow rate adjusting valve 18 and the downstream side of the bypass pipe 12 is provided with a circulation pipe 20 that circulates the stock solution 3 to the stock solution tank 2 through a circulation valve 19.

  With reference to FIG.2 and FIG.3, the ultraviolet irradiation device 1 of this embodiment is demonstrated. FIG. 2 is an internal schematic configuration diagram of the ultraviolet irradiation device 1 as viewed from the front, and FIG. 3 is an internal schematic configuration diagram of FIG. 2 as viewed from the top. As shown in FIG. 2, the ultraviolet irradiation device 1 includes a support pipe 21 whose outer peripheral surface is formed of a reflective material having ultraviolet rays, a spiral tube 22 spirally wound around the outer peripheral surface of the support pipe 21, and a spiral tube 22. And a plurality of straight tubular ultraviolet lamps (hereinafter referred to as UV lamps) 23 arranged in parallel to the axial direction of the support pipe 21, and accommodated in the reflection case 24 with their longitudinal directions being vertical. Has been.

  Here, the UV lamp 23 shown in the present embodiment is merely an example of an ultraviolet light source (UV light source), and the UV light source of the present invention is limited to a straight tubular low-pressure or medium-pressure ultraviolet lamp. It is not a thing. For example, a planar UV light source such as a UV-LED module or an excimer lamp may be used, and a U-shaped or W-shaped mercury lamp may be used. Furthermore, since the UV spectrum emitted from the UV light source varies depending on the type of the UV light source, it is preferable to appropriately select the type of the UV light source according to the purpose of sterilization or photochemical reaction.

  The spiral tube 22 is made of, for example, a fluororesin (for example, made of polytetrafluoroethylene) having an inner diameter of 6φ and an outer diameter of 8φ. However, the material, the inner diameter, and the outer diameter of the spiral tube 22 are not limited to these, and any material (for example, a quartz glass tube) may be used as long as it is an ultraviolet light transmissive material. It is preferable to select the outer diameter as appropriate in accordance with the treatment conditions of the ultraviolet irradiation. As shown in FIG. 3, the reflection case 24 is formed in a rectangular parallelepiped shape whose cross section perpendicular to the pipe axis of the support pipe 21 has a rectangular shape. The inner surface of the reflection case 24 is formed of an ultraviolet reflecting material. The reflection case 24 of the present embodiment is formed using a high-purity aluminum plate having a high ultraviolet reflectance. When the aluminum plate is oxidized, the reflectance is greatly lowered. Therefore, in order to maintain the reflectance of the inner surface of the reflection case 24, an aluminum plate coated with quartz glass is used.

  A support pipe 21 in which a spiral tube 22 is wound in a spiral shape and a plurality of UV lamps 23 are accommodated in a reflective case 24 with the longitudinal direction thereof being longitudinal. The support pipe 21 is supported by the ceiling wall and the bottom wall of the reflection case 24 through support members 32a and 32b, respectively. The ceiling wall and the bottom wall of the reflection case 24 are reinforced by reinforcing members 25a and 25b, respectively. The reflection case 24 is formed with as few openings as possible so that ultraviolet rays do not leak outside. If an opening is necessary, an opening having a shielding structure (not shown) that can block the leakage light of ultraviolet rays is used so that ultraviolet rays do not leak from the opening.

  The reflection case 24 is housed inside a box-shaped rectangular parallelepiped container 26 via a base member 27 and is provided with the container 26 fixed to the floor surface via a support member 28. Further, the reflection case 24 is surrounded by a container 26 so that ultraviolet rays do not leak outside. An opening that can be fully opened is provided on one surface of the container 26, and the opening is closed by a lid 26a that can be opened and closed. Although not shown in the figure, the accommodation devices such as the spiral tube 22 of the reflection case 24 generate heat when irradiated with ultraviolet rays. Therefore, the air in the container 26 is ventilated by a ventilation device (not shown) to cool the accommodation equipment of the reflection case 24. Note that the ventilation device is provided with a filter (not shown) that removes floating dust in the reflection case 24.

  The support pipe 21 is formed of a member that reflects at least an outer peripheral surface of ultraviolet rays. For example, an aluminum coating is formed on the outer peripheral surface of an aluminum pipe or resin pipe. Further, a reflecting material is formed by coating (coating) the outer peripheral surface of the aluminum pipe or the aluminum film with quartz glass. One or a plurality of spiral tubes 22 are arranged in parallel on the outer peripheral surface of the support pipe 21 and are wound in a spiral. The number of spiral tubes 22 in parallel is determined according to design conditions such as the processing flow rate of the stock solution 3, the processing speed, the ultraviolet absorbance (or ultraviolet transmittance) of the stock solution 3, and the residence time. Although this embodiment shows an example in which two are wound in parallel, the present invention is not limited to this.

  The UV lamp 23 is a straight tube type mercury lamp, and as shown in FIG. 3, each of the UV lamps 23 has a plurality of UV lamps 23 along inner surfaces 24c, 24d facing each other with the support pipe 21 therebetween. The UV lamp groups A and B are arranged separately. In the present embodiment, the UV lamp groups A and B are each composed of six UV lamps 23, but the number of UV lamps 23 is not limited to this example, and an appropriate number is selected according to the design conditions described above. Just decide.

  Each of the UV lamp groups A and B is configured such that each UV lamp 23 is detachably attached to a socket 30 provided on the upper and lower opposing sides of the rectangular frame 29. The plurality of UV lamps 23 assembled to the frame body 29 are formed as UV lamp units. Although not shown, each UV lamp unit fixes the upper and lower opposing side portions of the frame body 29 to the reflection case 24 so as to be detachable, and the reflection case 24 and the side portions of the frame body 29 are attached. The container 26 can be pulled out. That is, the reflective case 24 and the container 26 are provided with an open / close door structure or a detachable sidewall so that each UV lamp unit can be pulled out. In FIG. 3, reference numerals 31a and 31b denote seal members.

  Next, the operation of the bubble stirring type ultraviolet irradiation device of the present embodiment configured as described above will be described. In the stock solution tank 2, the stirrer 4 is operated so that the slurry of the stock solution 3 does not precipitate and the concentration is uniform. The pump 6 is operated to supply the stock solution 3 to the ultraviolet irradiation device 1 through the stock solution supply pipe 7, but the flow rate adjustment valve 18 of the stock solution supply pipe 7 is closed and circulated until the gas blowing device 11 is started. The valve 19 is opened and the stock solution 3 is returned to the stock solution tank 2 through the circulation pipe 20 to circulate the stock solution 3. Next, the gate valve 13 a 13 b of the gas blowing device 11 is opened, and the stock solution 3 is circulated through the bypass pipe 12. The gas supply source 16 is a suction port having a filter opened in a clean atmosphere when air is used as a gas. However, when other types of gas are used, a gas holder filled with the gas and necessary In some cases, a gas compressor is provided.

Then, the adjustment valve 17 of the air supply pipe 15 is opened, and the gas supply source 16 is communicated with a suction port (not shown) of the ejector 14. As a result, the pressure of the suction port of the ejector 14 becomes negative due to the flow of the stock solution 3 flowing through the circulation pipe 20, and air is sucked into the ejector 14 from the gas supply source 16 and blown into the stock solution 3 as fine bubbles. Then, it is circulated to the stock solution tank 2 through the circulation pipe 20. The supply flow rate L [m ³ / min] of the stock solution 3 at this time is measured by the flow meter 13c, and the gas flow rate A [m ³ / min] is measured by the flow meter 15a. The supply pressure of the stock solution 3 is measured by a pressure gauge 13d. Here, the circulation valve 19 and the flow rate adjustment valve 17 for the air supply amount are adjusted so that the gas-liquid ratio A / L of the supply flow rate L of the stock solution 3 and the gas injection flow rate A becomes the set ratio β.

  Next, the UV lamp 23 of the ultraviolet irradiation device 1 is turned on, the flow rate adjustment valve 18 is opened, and the circulation valve 19 is closed. As a result, the stock solution 3 in which bubbles are blown into the spiral tube 22 of the ultraviolet irradiation device 1 is circulated, and the ultraviolet light irradiated from the UV lamp 23 is irradiated to the stock solution 3 flowing in the spiral tube 22. Here, while confirming the supply flow rate L of the undiluted solution 3 to the ultraviolet irradiation device 1, the flow rate A of the flow rate adjustment valve 18 and the flow rate adjustment are adjusted so that the gas injection flow rate A is confirmed and the gas / liquid ratio L / A becomes the set ratio β. Adjust valve 17. It goes without saying that the power supplied to the UV lamp 23 of the ultraviolet irradiation device 1 is adjusted as necessary. Moreover, the temperature in the container 26 is measured, and the temperature in the container 26 is adjusted by turning the ventilation fan.

The stock solution 3 containing bubbles circulated in the spiral tube 22 of the ultraviolet irradiation device 1 has a substantial UV transmittance UVT = 10− ^α (α is the absorbance of the stock solution) of the stock solution 3 due to the stirring action of the stock solution 3 by the bubbles. The amount of ultraviolet irradiation with respect to the stock solution 3 is increased.

  Here, the stirring action of the undiluted solution by the bubbles will be specifically described. The undiluted solution 3 in an extremely thin region (hereinafter referred to as an ultrathin region) in contact with the inner wall of the spiral tube 22 is effectively irradiated with ultraviolet rays through the spiral tube 22 having high ultraviolet transmittance. However, if the ultraviolet light absorbance of the stock solution 3 is high, UV light may not reach the stock solution 3 flowing in the center of the tube. In addition, the flow of the stock solution 3 in the ultrathin region in contact with the inner wall of the spiral tube 22 is a stable flow in contact with the inner wall of the tube, and is difficult to mix with the stock solution 3 flowing through the center side of the spiral tube 22.

  Therefore, in this embodiment, bubbles are blown into the stock solution 3 flowing through the spiral tube 22, and the stock solution layer in the ultrathin region that flows stably in contact with the inner wall of the spiral tube 22 is peeled off from the inner wall of the tube by bubbles. The stock solution is stirred by changing the stock solution layer in the thin region. That is, the stable stock solution layer on the inner wall of the spiral tube is peeled off by the bubbles, and a new stock solution layer is formed on the inner wall after the peeling. In this way, the ultraviolet rays are irradiated to the newly formed stock solution layer that is replaced, and the ultraviolet irradiation rate with respect to the stock solution is improved as a whole, the ultraviolet ray irradiation amount distribution is improved, and the ultraviolet ray irradiation amount can be increased. Furthermore, the stirring efficiency of the stock solution is further enhanced by the behavior of bubbles due to buoyancy in the stock solution.

  In addition, since the transmittance of the bubbles is much higher than that of the stock solution 3, the ultraviolet rays applied to the bubbles near the inner wall of the spiral tube 22 are diffusely reflected in the bubbles and are applied to the stock solution 3 in contact with the bubbles. The irradiation area of the stock solution 3 irradiated with ultraviolet rays is increased by the surface area of the bubbles, and the ultraviolet irradiation rate per unit length of the spiral tube 22 is improved. As a result, the amount of ultraviolet irradiation with respect to the stock solution 3 can be increased.

The amount of ultraviolet irradiation is evaluated per unit area (for example, mj / cm ^{2 in} terms of UV output of an ultraviolet light source) in the case of a stock solution targeted for detoxification of a pathogen, and in the case of a stock solution subject to photochemical reaction. Generally, it is evaluated by hit (for example, mj / cm ^{3 in} terms of UV output of an ultraviolet light source). However, as described above, in the present embodiment, since an undiluted solution (including slurry and the like) having a low ultraviolet light transmittance, that is, a high ultraviolet absorbance is used as a processing target, ultraviolet rays are absorbed by the undiluted solution. Therefore, even when not used in combination with the photochemical reaction technique, the evaluation is performed in consideration of the ultraviolet absorbance of the stock solution 3.

  As described above, according to the present embodiment, the substantial ultraviolet transmittance of the stock solution 3 can be remarkably improved by the combined action of bubbles formed by blowing gas into the stock solution 3 flowing in the spiral tube 22. In comparison with the conventional method in which no gas is blown, the amount of ultraviolet irradiation to the stock solution can be remarkably increased. Further, by adjusting various parameters of the bubbles (for example, the amount (volume ratio) of bubbles with respect to the stock solution, the particle size of the bubbles, the type of gas, etc.) according to the difference in the ultraviolet transmittance of the stock solution 3, Even for the stock solutions 3 having different transmittances (or ultraviolet absorbances), highly efficient ultraviolet irradiation can be performed by narrowing the width of the ultraviolet irradiation distribution. In particular, it is possible to adjust to the necessary UV irradiation amount by reducing the excessive irradiation amount and the under irradiation amount as much as possible in correspondence with the stock solution 3 to be detoxified or photochemical reaction target.

  In addition, as described in the above embodiment, the present invention blows gas into the stock solution 3 flowing in the spiral tube 22, thereby irradiating ultraviolet rays with high efficiency by the combined action based on the stirring effect described above. The amount can be increased. However, the amount of ultraviolet irradiation cannot be increased with high efficiency as in the present invention by simply blowing bubbles into the stock solution flowing in the flow path of the conventional ultraviolet irradiation apparatus. For example, when a gas-liquid mixed phase flow is formed by blowing bubbles into a flow-type internally-illuminated ultraviolet irradiation device that flows around a conventional conventional ultraviolet light source, a short path of liquid flow around the bubbles due to the buoyancy of the bubbles Will occur. Such a short-passed microfluidic mass flows out in a shorter time (with a shorter residence time) than a microfluidic mass that has not been short-passed, and therefore flows out of the ultraviolet irradiation device with a low ultraviolet irradiation amount. For this reason, in a normal liquid-flow type ultraviolet irradiation device, by making the gas-liquid mixed phase flow, the ultraviolet irradiation amount distribution becomes wider and the ultraviolet irradiation efficiency is lowered.

  In this regard, according to the present invention, the rising of the bubbles physically stops at the upper part of the inner wall of the spiral tube, and a short path cannot be made beyond the physical upper end due to the tube diameter and the spiral winding diameter. For this reason, since all the microfluids are flowed out with a substantially uniform residence time, the ultraviolet irradiation amount distribution is narrowed and the ultraviolet irradiation efficiency is improved. Furthermore, the fluid in the spiral tube turns into a spiral flow that is swirled by centrifugal force and inertial force, and the buoyancy of bubbles in the gas-liquid mixed phase flow is also added, so that the fluid is mixed more intensely and the inside of the spiral tube is close to plug flow (plug flow) Since it flows in a state, the width of the UV irradiation distribution becomes extremely narrow. Thereby, highly efficient ultraviolet irradiation is attained. In other words, stirring the undiluted solution in the spiral tube is a major factor in increasing the UV irradiation amount by narrowing the UV irradiation amount distribution or UV absorption amount distribution.

  Moreover, when the volume of the gas injected with respect to the volume of the liquid is large, or when the tube diameter is small, the gas and the liquid (gas-liquid mixed phase flow) flow alternately. However, in this case as well, the undiluted solution in contact with the inner wall of the tube is constantly peeled off by the gas, and is close to a plug flow (plug flow) where the entire solution is vigorously stirred due to the effects of inertial force, centrifugal force and buoyancy of the gas-liquid mixed phase Since it flows in a state, the width of the UV irradiation distribution becomes extremely narrow. Thereby, highly efficient ultraviolet irradiation is attained.

  On the other hand, when the fluid is slurry, if the flow rate is slow, the powder may settle inside the spiral tube and clogging may occur inside the tube. However, by using a gas-liquid mixed phase flow, the powder can be stirred without settling. It is possible to distribute it. In addition, when the fluid is slurry, as described above, the undiluted solution in contact with the inner wall of the tube is constantly separated by gas, and inertial force and centrifugal force, gas buoyancy, and powder gravity act on the gas-liquid solid-phase flow. However, since the whole fluid flows in a state close to a vigorously stirred plug flow (plug flow), the width of the ultraviolet ray irradiation amount distribution becomes extremely narrow. Thereby, highly efficient ultraviolet irradiation is attained.

  The processing liquid that has flowed through the spiral tube 22 and has been processed by ultraviolet irradiation is discharged to a processing liquid tank 9 having a pressure regulating valve 10. The gas in the processing liquid is gradually degassed by adjusting the pressure adjustment valve 10 or automatically adjusting to the set pressure. That is, the supply pressure of the stock solution 3 needs to be increased according to the pressure loss at which the gas-liquid two-phase flow of the stock solution 3 in which bubbles are blown flows through the spiral tube 22 according to the processing amount of the stock solution 3. That is, when the supply pressure PL of the stock solution 3 is high, the volume of the blown gas is compressed according to the supply pressure PL. Therefore, if the processing liquid is suddenly released to the atmospheric pressure in the processing liquid tank 9, bubbles are evacuated from the processing liquid in the processing liquid tank 9, so that the processing liquid may undulate in the processing liquid tank 9. There is. Therefore, the deaeration speed is adjusted by the pressure adjustment valve 10. As a result, it is possible to avoid the intense waving of the processing liquid and to stably deaerate. If necessary, a vacuum deaeration or a deaeration pump may be provided.

  In the above embodiment, the gas blowing device is configured by using the ejector 14, but the present invention is not limited to this, and may be an air diffuser nozzle that injects gas into the stock solution 3 as bubbles. . In this case, the gas supply source 16 is provided with a compressor that compresses gas and supplies it to the diffuser nozzle. Further, the stock solution 3 can be continuously supplied to the stock solution tank 2. Further, the processing liquid in the processing liquid tank 9 can be continuously discharged to the next process.

  In the above embodiment, the spiral tube 22 is wound around the outer peripheral surface of the support pipe 21. However, the present invention is not limited to this, and the support pipe 21 is omitted, and the spiral tube 22 is An air core that is spirally wound may be used. In this case, the spiral tube 22 may be supported on the ceiling wall and the bottom wall of the reflection case 24 by some means. Further, a plurality of UV lamps 23 may be arranged in the spiral air core of the spiral tube 22 or outside the spiral tube 22. Further, in the above-described embodiment, the example in which the support pipe 21 around which the spiral tube 22 is wound is arranged vertically is shown. However, the support pipe 21 may be arranged horizontally, for example, horizontally. Also, an air-core spiral tube can be disposed sideways. In this case, the arrangement of the UV lamps 23 may be changed as appropriate, and an appropriately shaped UV light source may be selected.

  Furthermore, in the above embodiment, an example is shown in which a plurality of UV lamps 23 are arranged in two UV lamp groups A and B along the opposing inner surfaces 24c and 24d of the reflection case 24 with the support pipe 21 interposed therebetween. It was. However, the present invention is not limited to this, and a plurality of spiral tubes 22 may be arranged in a cylindrical shape outside the spiral of the spiral tube 22. In this case, the reflection case 24 and the container 26 can be formed in a cylindrical shape.

  In the above-described embodiment, it is useful due to the technology for detoxifying the pathogen contained in the liquid food etc. by irradiating the ultraviolet ray, or by the photochemical reaction of the specific component contained in the liquid food etc. by irradiating the liquid food etc. with the ultraviolet ray. An example of the case where it is applied to a technique for generating components (for example, vitamins) or changing or decomposing components that affect the taste or odor is given as an example. explain.

(Specific examples used for photochemical reactions)
As an example applied to the photochemical reaction, an example of an advanced oxidation process (AOP) using ozone and ultraviolet rays will be described. An ozone-promoted oxidized water treatment system combined with ultraviolet rays, ozone gas is dissolved in water to form dissolved ozone, ultraviolet rays are irradiated to the dissolved ozone to generate hydroxy radicals, and the generated organic radicals oxidize and decompose dissolved organic compounds in water A water treatment technique is described in, for example, Japanese Patent Application Laid-Open No. 2003-266088.

  The water targeted by the water treatment apparatus using such a photochemical reaction is not limited to clean water, but oxidatively decomposes dissolved organic compounds of various types of water such as sewage, wastewater, reclaimed water, industrial water, and industrial water. Applies to processing. In such a water treatment apparatus, the dissolved gas concentration of the gas used for the reaction is extremely important. In the prior art described in the above-mentioned patent document, it is difficult to increase the dissolved ozone concentration because the ozone bubbles short pass. Moreover, since residual ozone that could not be consumed in the treated water as bubble ozone accumulates in the upper part of the treatment tank, the effective utilization efficiency of ozone is poor. In addition, there is a problem that an apparatus for treating the residual ozone is required separately.

  In this regard, by applying the bubble stirring type ultraviolet irradiation device 1 of the above embodiment, selecting ozone as a gas to be applied to the photochemical reaction, and configuring an ozone-promoted ozone water treatment system using ultraviolet rays, it is possible to achieve high efficiency. AOP processing is possible. That is, ozone is injected into the ultraviolet irradiation device 1 of the above-described embodiment with an ejector or the like, and is circulated through the spiral tube 22 as a gas-liquid mixed phase flow. Thereby, ozone dissolves in water efficiently, and the efficiency of the oxidative decomposition reaction of the target substance can be improved as compared with the conventional AOP treatment. Further, due to the combined action of the centrifugal force and inertial force of the gas-liquid mixed phase flow and the buoyancy of the ozone bubbles, ozone can be dissolved from the ozone bubbles into the liquid phase with high efficiency and the dissolved ozone concentration can be increased.

  On the other hand, in the case of conventional AOP treatment, when raw water is circulated in a relatively large-diameter container, ozone is injected into the raw water and irradiated with ultraviolet rays for oxidation treatment, ozone bubbles are generated by buoyancy. Since a short path that reaches the upper part of the vessel ascending in water occurs, the efficiency of the oxidative decomposition reaction of the target substance cannot be improved.

  Further, in the ultraviolet irradiation apparatus of the present invention used for the AOP process, when the pressure adjusting valve 10 of the processing liquid tank 9 and the processing liquid tank 9 are omitted, the pressure adjusting valve 10 is provided in the liquid supply pipe 8 on the outlet side of the spiral tube 22. The dissolved ozone concentration can be arbitrarily increased by providing and adjusting the pressure regulating valve 10 to increase the internal pressure of the spiral tube 22.

  Furthermore, due to the stirring effect of the raw water described in the above embodiment, the microfluid mass in which dissolved ozone and the target substance are dissolved efficiently approaches or contacts the inner surface of the tube, and is irradiated with ultraviolet rays to generate hydroxy radicals. The oxidative decomposition reaction of the substance can be caused promptly.

  In addition, the reaction is instantaneously completed in the microfluidic mass, and both the dissolved ozone concentration and the target substance concentration in the microfluidic mass decrease, but the dissolved ozone quickly moves from the bubble ozone to the microfluidic mass by the fluid stirring effect and concentration diffusion effect. Supplied and mixed. That is, a series of accelerated oxidation reaction processes in which dissolved ozone is generated from bubble ozone, hydroxy radicals are generated from dissolved ozone, and oxidative decomposition of the target substance is instantaneously increased while circulating in the spiral tube 22. Done continuously with efficiency. As a result, compared to the prior art, it is possible to prevent outflow due to ineffective consumption of bubble ozone and increase the effective consumption rate of ozone.

  On the other hand, regarding the ultraviolet irradiation device of the present invention used for AOP treatment, when attention is paid to the amount of absorbed ultraviolet light, according to the present invention, the dissolved ozone concentration in the microfluidic mass can be increased, and the dissolved ozone in the microfluidic mass is further increased. Since the amount of UV absorption to be absorbed can be increased, the concentration of hydroxy radicals in the microfluidic mass can be increased.

  Moreover, while the target substance concentration and dissolved ozone concentration in the microfluid mass from inflow to outflow decrease by the accelerated oxidation reaction, they are constantly replenished and diluted by physical stirring and concentration diffusion. However, since the UV absorption amount absorbed by the dissolved ozone in each microfluid mass in the fluid from the inflow to the outflow becomes substantially uniform, the width of the ultraviolet absorption amount distribution of the dissolved ozone becomes extremely narrow. For this reason, the effect that reaction efficiency becomes very high is acquired.

  Moreover, it is preferable to provide the pressure adjusting valve 40 in the liquid supply pipe 8 on the outlet side of the spiral tube 22 instead of or in addition to the pressure adjusting valve 10 of FIG. Thereby, the pressure regulating valve 40 is adjusted, the internal pressure of the spiral tube 22 is increased, the dissolved oxygen concentration or the dissolved gas concentration can be arbitrarily increased, and the reaction efficiency can be further increased.

(Specific examples applied to photocatalytic reactors)
It is known that hydroxy radicals are generated on the surface of the photocatalyst when the photocatalyst is irradiated with ultraviolet rays. The photocatalyst can be formed into a fine particle size (for example, 0.2 μm or more) that can be filtered with a microfilter membrane by various methods such as support on activated carbon, glass beads, nonwoven fabric, etc., or baking and granulating. Are known.

  However, the photocatalytic reaction is a surface reaction, and hydroxy radicals are generated only on the surface of the photocatalyst irradiated with ultraviolet rays. Therefore, if the particle size is large, the specific surface area of the photocatalyst becomes small and sufficient reaction efficiency cannot be obtained. Therefore, it is preferable to use a photocatalyst powder that can be membrane-filtered and molded into a particle size as small as possible. However, although the specific surface area per weight of the photocatalyst increases, in order to ensure the necessary hydroxy radical concentration, it is necessary to inject a high concentration photocatalyst powder into the treated raw water to form a slurry. However, as described above, ultraviolet rays are irradiated only on the surface of the slurry near the light source, and no hydroxyl radicals are generated because the ultraviolet rays do not reach inside the slurry away from the ultraviolet light source. Therefore, even if the photocatalyst particle size is reduced to increase the specific surface area and the photocatalyst concentration is further increased, the photocatalyst surface area that can be irradiated with ultraviolet rays cannot be increased, so that the hydroxy radical concentration necessary for water treatment cannot be ensured. There's a problem. Furthermore, since the hydroxyl radical is generated from water and dissolved oxygen, when the photocatalytic reaction proceeds, there is also a problem that the dissolved oxygen concentration decreases and the reaction efficiency decreases.

  In this regard, by applying the bubble stirring type ultraviolet irradiation device of the above-described embodiment to the photocatalytic reaction device, it is possible to solve the above-described problems and realize a highly efficient photocatalytic reaction device. That is, photocatalyst particles having a fine particle size that can be filtered with a filter membrane such as a microfilter membrane are charged into the treated raw water, and are made into a slurry and distributed to the ultraviolet irradiation device of the above embodiment. Air is injected into the treated raw water by the ejector 14 and circulated through the spiral tube 22 as a gas-liquid solid mixed phase flow. As a result, as described above, the fluid in contact with the inner wall of the spiral tube 22 is continuously peeled off by the bubbles, and the centrifugal force and inertial force of the fluid, gravity sedimentation of the photocatalyst particles, and the buoyancy of the fine bubbles act in a complex manner. While stirring, the inside of the spiral tube 22 flows in a state close to plug flow (plug flow).

  Furthermore, according to the photocatalytic reaction apparatus using the bubble stirring type ultraviolet irradiation apparatus of the above embodiment, the spiral tube 22 made of ultraviolet transparent fluororesin diffuses and transmits ultraviolet rays, so that the tube wall is substantially surface. Light source. Further, in the gas-liquid mixed phase flow including the photocatalyst flowing through the spiral tube 22, the ultraviolet rays applied to the bubbles near the inner wall of the tube are diffusely reflected in the bubbles and effectively irradiated to the stock solution in contact with the bubbles. That is, ultraviolet rays are irradiated from the entire surface of the bubbles to the photocatalyst in the microfluidic mass, and the irradiation area of the ultraviolet rays is substantially increased.

  As a result, the frequency of the target substance dissolved in the microfluid mass reacting with the photocatalyst particle surface and the hydroxyl radical in contact with or approaching the inner wall surface of the tube is dramatically increased. In other words, the width of the ultraviolet ray irradiation distribution received by the photocatalyst particles in each microfluid mass from the inflow to the outflow to the ultraviolet irradiation device can be extremely narrowed. Thereby, the efficiency of a photocatalytic reaction can be improved significantly. In addition, since air is injected and circulated as a spiral flow, even if dissolved oxygen is consumed by the photocatalytic reaction, the dissolved oxygen is continuously supplied from the bubbles, so the reaction efficiency does not decrease due to the lack of dissolved oxygen. . The injected or introduced photocatalyst particles are extracted by a processing liquid discharge pipe 40 connected to the bottom of the processing liquid tank 9 in FIG. 1, guided to a photocatalyst recovery device (not shown), and separated by a filter membrane. And can be recovered. That is, it is preferable to apply the above-described embodiment to a photochemical reaction apparatus and add to the stock solution 3 photocatalyst particles having a fine particle size that can be filtered with a filter membrane. Thereby, the production | generation reaction of the target substance (target component) accompanying a photochemical reaction and the decomposition reaction of a harmful | toxic component can be accelerated | stimulated effectively.

  As mentioned above, although this invention was demonstrated based on one Embodiment, this invention is not limited to these, It is possible to implement in the form deform | transformed or changed in the range of the main point of this invention. It will be obvious to those skilled in the art, and it is obvious that such variations or modifications belong to the scope of the claims of the present application.

DESCRIPTION OF SYMBOLS 1 Ultraviolet irradiation device 2 Stock solution tank 3 Stock solution 4 Stirrer 6 Pump 7 Stock solution supply piping 9 Processing solution tank 10, 40 Pressure adjustment valve 11 Gas blowing device 12 Bypass piping 14 Ejector 15 Air supply pipe 16 Gas supply source 21 Support pipe 22 Spiral tube 23 Ultraviolet lamp (UV lamp)
24 Reflective case 26 Container 29 Frame

Claims (14)

In the ultraviolet irradiation method of irradiating the stock solution with ultraviolet rays from at least one of the inside and the outside of the spiral of the spiral tube, circulating the spirally wound stock solution to be irradiated with ultraviolet rays through a spiral tube having ultraviolet permeability.
A bubble stirring type ultraviolet ray processing method, wherein a gas is blown into the stock solution.   The gas is at least selected from air, oxygen gas, carbon dioxide gas, inert gas, or a specific gas suitable for generating, decomposing, or chemically changing a target substance by photochemical reaction of the specific substance in the stock solution. The bubble stirring type ultraviolet ray processing method according to claim 1, wherein the gas is a single gas.   3. The bubble stirring type ultraviolet ray treatment method according to claim 2, wherein in order to promote the photochemical reaction, photocatalyst particles having a fine particle size that can be filtered with a filter membrane are added to the stock solution.   A stock solution supply pipe that supplies a stock solution that is a liquid to be treated, a gas blowing device that blows gas into the stock solution that flows through the stock solution supply pipe, and a gas bubble that is blown into the stock solution from the gas blowing device A bubble-stirring type ultraviolet irradiation comprising: a spirally wound spiral tube wound in a spiral shape through which a stock solution is distributed; and an ultraviolet light source disposed on at least one of the inside and the outside of the spiral of the spiral tube apparatus.   The gas is at least selected from air, oxygen gas, carbon dioxide gas, inert gas, or a specific gas suitable for generating, decomposing, or chemically changing a target substance by photochemical reaction of the specific substance in the stock solution. The bubble stirring type ultraviolet irradiation device according to claim 4, wherein the bubble irradiation type ultraviolet irradiation device is a single gas.   6. The bubble stirring type ultraviolet irradiation device according to claim 5, wherein the gas blowing device is an air diffuser nozzle that injects the gas into bubbles into the undiluted solution flowing through the undiluted solution supply pipe.   7. The bubble stirring type ultraviolet irradiation device according to claim 6, wherein the gas blowing device includes a compressor that compresses the gas and supplies the compressed gas to the diffuser nozzle.   The gas blowing device includes a bypass pipe provided in the stock solution supply pipe and an ejector provided in the bypass pipe. The ejector includes a throttle section through which the stock solution is circulated, The bubble stirring type ultraviolet irradiation device according to claim 5, further comprising a suction port provided in an inner surface and connected to a gas supply source.   The bubble agitating type of claim 4, wherein the spiral tube is spirally wound around and supported by an outer peripheral surface of a support pipe, and the ultraviolet light source is disposed outside the spiral of the spiral tube. UV irradiation device.   The spiral tube is formed of a plurality of spiral tubes connected in parallel, and the plurality of spiral tubes are supported by being wound in a single spiral along the outer peripheral surface of the support pipe. 10. A bubble stirring type ultraviolet irradiation device according to 9. The stock solution is supplied to the spiral tube via a flow rate adjustment valve provided in the stock solution supply pipe,
The bubble stirring type ultraviolet irradiation device according to any one of claims 6 to 8, wherein the gas is supplied to the gas blowing device through a flow rate adjusting valve.   The bubble stirring type ultraviolet irradiation device according to claim 4, wherein the stock solution is water and the gas is ozone. Furthermore, a pressure adjustment valve is provided in the water supply pipe of the treated water discharged from the spiral tube,
The bubble agitation method according to claim 4, wherein the pressure adjustment valve is adjusted to increase the internal pressure of the spiral tube and to increase the dissolved gas concentration of the water in the spiral tube to a set concentration. UV irradiation device.   5. The bubble stirring type ultraviolet irradiation device according to claim 4, wherein the stock solution is a stock solution containing photocatalyst particles having a fine particle size that can be filtered with a filter membrane.

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