JPH01315386A - Photochemical reactor - Google Patents

Abstract

PURPOSE:To uniformize a reaction in the title reactor by connecting an inlet pipe and an outlet pipe to the reactor so that a liq. reactant flows in the main reaction vessel as a spiral flow, and arranging a light source to traverse the spiral flow. CONSTITUTION:A liq. reactant is introduced from the liq. reactant inlet pipe 6 as shown by the arrow (p), a chemical is injected from a chemical feeder 9 through a chemical injection pipe 8, hence the liq. reactant reacts with the chemical in the main reaction vessel 1, and the reaction product is discharged from a liq. reactant outlet pipe 7 as shown by the arrow (q), In this case, the liq. mixture of the liq. reactant introduced from the inlet pipe 6 and consisting of service water, etc., and the chemical proceeds as the spiral flow called the cyclonic flow as shown by the arrow (s). In this case, the spiral flow is successively cut by protecting tubes 2a-4a contg. UV lamps 2-4. As a result, a regular Karman vortex K is successively generated around the protecting tubes 2a-4a. By this method, extremely uniform mixing and uniform light irradiation are simultaneously carried out, the light irradiation is uniformized, and the reaction is uniformly promoted.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a photochemical reaction device that promotes a reaction by irradiating a reaction liquid flowing in a reaction container with light, and particularly relates to a photochemical reaction device that promotes a reaction by irradiating a reaction liquid flowing in a reaction container with It is designed to effectively achieve the two effects of uniform light irradiation and mixing of the reaction liquid at the same time without using a mixing means, and it contains solid substances such as photo-oxidation treatment of water and colloid components. This invention relates to a product that can be used for sterilization of liquid liquids using a combination of chemicals and ultraviolet rays.

[Prior Art] This type of photochemical reaction device has conventionally been used, for example, to circulate a liquid to be treated such as industrial water, liquid food, or pharmaceuticals through a cylindrical tube, and to irradiate the liquid with ultraviolet rays. A so-called ultraviolet sterilizer that sterilizes a treatment liquid is known.

By the way, in the photochemical reaction device, in order to perform a uniform reaction, it is necessary to uniformly irradiate the entire circulating reaction liquid with light. However, depending on the reaction solution or the irradiated light, the transmittance of light through the reaction solution is extremely poor.
If the reaction liquid is simply made to flow near the light source, only a portion of the reaction liquid passing very close to the light source will be irradiated with light, and uniform light irradiation may not be possible.

This tendency is particularly noticeable when using ultraviolet light, which has low transmittance for most substances, as in the case of the ultraviolet sterilizer.

For this reason, although the ultraviolet sterilizer has been put into practical use for sterilizing liquids with a high transmittance to ultraviolet rays, it is used to sterilize colloidal liquids such as milk, secondary treated water from sewage, and other types of ultraviolet sterilizers. It has been extremely difficult to apply this method to sterilize liquids that have extremely low transmittance to ultraviolet light, such as solid-containing liquids.

In recent years, in order to put this ultraviolet sterilizer into practical use for sterilizing solids-containing liquids, the liquid layer of the treatment liquid has been thinned and at the same time the area of ultraviolet irradiation has been widened to increase the irradiation efficiency. Attempts have been made to blow in a gas such as air and stir the solution so that the entire treatment solution is uniformly exposed to ultraviolet rays.

In addition, even in photochemical reaction devices using ultraviolet irradiation methods other than the ultraviolet sterilizer mentioned above, the inner surface of the reaction container is made into an ultraviolet reflecting mirror and is formed into a so-called "rain gutter" shape.
The reaction solution is introduced so as to flow in a state close to turbulence in the "rain gutter"-shaped container, and the effect of improving the irradiation efficiency of ultraviolet rays by the reflector and the turbulent flow inside the "rain gutter"-shaped container are achieved. Attempts have been made to ensure uniform light irradiation using the stirring effect caused by the distribution.

[Problems to be Solved by the Invention] However, each of the above-mentioned conventional examples has the following drawbacks.

In other words, when trying to widen the irradiation area by thinning the liquid layer as in the ultraviolet sterilizer described above, the flow rate of the reaction liquid flowing through is restricted, resulting in a limit to the amount of treatment. is likely to be wasted without being effectively absorbed.

However, although the method of stirring by blowing gas can achieve a stirring effect in the sense of evenly mixing the liquid locally, it cannot necessarily achieve the sufficient effect of exposing each part of the liquid to the light source evenly. As a result, it is not always possible to obtain a sufficiently uniform reaction, and the structure of the apparatus is also complicated.

Furthermore, in the case of using the above-mentioned "rain gutter" shaped container, if the reaction liquid flows in the reaction container in a completely turbulent flow, uniform light irradiation can theoretically be obtained. However, each of the conventional methods described above is based on the condition that it can be roughly considered as "turbulent flow" in fluid mechanics (for example, if the Reynolds number is calculated from the pipe diameter and flow velocity and is about 4000 or more, it is considered turbulent. The reaction vessel was designed by mechanically applying the flow (which was considered to be a flow). That is, for example, how to connect a reaction liquid introduction pipe for introducing a reaction liquid into the reaction vessel and a reaction liquid discharge pipe for discharging the reaction liquid to the reaction vessel is as follows.
Either the inlet tube and the outlet tube are connected at both ends of the reaction vessel such that their center lines are both perpendicular to the tube center line of the reaction vessel, or the center lines of the inlet tube and the outlet tube are connected so that the center line of the outlet tube is The tubes were connected so that their center lines were parallel.

However, the device obtained in this way did not achieve the expected performance as expected in the calculations at the time of design, and in the end, it was necessary to secure the amount of light by using a large light source that was not necessary in the design. There was a drawback that a uniform reaction could not be obtained without proper treatment. According to the inventor's considerations, this is due to the fact that when designing the conventional reaction vessel, the pipe diameter and flow rate are set simply based on the Reynolds number. This seems to be due to the fact that the reaction solution is considered to be in a completely ``turbulent flow''. In other words, even though it can be considered a ``turbulent flow'' from the Reynolds number, it is important to note that ``every part of the reaction liquid is uniformly irradiated with light'', that is, the distance between the trajectory of each part of the reaction liquid and the light source. From the viewpoint that the average values are statistically the same, it cannot be considered a "turbulent flow" unless not only the Reynolds number but also the linear flow velocity vector of the fluid inside the reaction vessel are taken into account. It is thought that uniform light irradiation could not be obtained in conventional reaction vessels designed without such consideration.

If uniform light irradiation is not obtained, for example, when a chemical is mixed into the water and reacted, as in the case of treatment of industrial water, the unevenness of the reaction due to non-uniform light irradiation will cause active reaction in the reaction vessel. This results in uneven drug concentration, which acts synergistically with the uneven reaction to further promote non-uniformity of the reaction, resulting in a vicious cycle.

An object of the present invention is to provide a photochemical reaction device that eliminates the above-mentioned drawbacks.

[Means for Solving the Problems] The present invention provides a reaction liquid inlet pipe and a reaction liquid discharge pipe in the reaction container body so that the reaction liquid advances in a helical flow inside the reaction container main body. At the same time, a rod-shaped light source for light irradiation is placed inside the reaction vessel body along the longitudinal direction of the reaction vessel body so as to cut the reaction liquid advancing in the spiral flow. The two functions of uniform light irradiation and mixing of the reaction solution can be effectively obtained at the same time with an extremely simple configuration without using any dynamic mixing means such as the following configuration. has.

A reaction vessel is provided with a substantially cylindrical reaction vessel body, and a rod-shaped light source disposed within the reaction vessel body along the longitudinal direction of the reaction vessel body, and a reaction liquid is introduced into the reaction vessel body to cause the reaction. A photochemical reaction device that promotes a reaction by irradiating light emitted from the light source through a container body, the reaction container body having a reaction liquid for introducing a reaction liquid into the reaction container. A liquid introduction pipe and a discharge pipe for discharging the introduced reaction liquid are connected, and the reaction liquid introduction pipe is connected to the reaction liquid introduced from the introduction pipe into the reaction vessel main body. The light source is connected to the reaction vessel main body in such a manner that the reaction liquid flows in a helical flow inside the reaction vessel main body and proceeds toward the discharge pipe side, and the light source is connected to the reaction liquid flowing in a helical flow inside the reaction vessel main body. A photochemical reaction device characterized in that it is arranged so as to cut off a flow.

[Function] In the above-described configuration, the reaction liquid introduced into the reaction vessel main body advances in the reaction vessel main body in a helical flow and is discharged from the discharge pipe.

At this time, the flow of the reaction solution is repeatedly cut off by the light source. As a result, a regular Karman vortex is generated around this light source as shown by the following equation.

f=st-y/d however, f; frequency St: Strouhal number (approximately 0.2) V; flow velocity d; Diameter of light source shall be.

In this way, the flow of the reaction solution is repeatedly cut by the light source, and a Karman vortex is formed each time.

That is, since a part of the introduced reaction liquid first passes very close to the light source when its flow is cut off, at that time, at the 0th order where it is sufficiently irradiated with light, at the same time as the flow is cut off,
Since a Karman vortex is formed, a part of the reaction liquid that has passed very close to the light source and another part of the reaction liquid that has passed through a relatively distant part are evenly mixed. The flow of the evenly mixed reaction solution is again cut off by the light source, and light irradiation and mixing are performed in the same manner. Such actions are repeated one after another according to the helical flow of the reaction solution.

In this case, the mixing by the Karman vortex can be considered to be almost ideal mixing, so the parts that passed very close to the light source and were irradiated with relatively strong light and the parts that were not mixed uniformly. Ru. Therefore, the next time the flow is cut off, it is only a part of this uniformly mixed reaction liquid that passes very close to the light source, and the part that has passed very close to the light source may pass through the vicinity again. Alternatively, a portion of the reaction solution that has passed through a region relatively distant from the light source does not pass through a region relatively distant again. That is, the reaction is uniformly promoted without unevenness in light irradiation.

Moreover, when mixing chemicals with water and causing a reaction, as in the above-mentioned water treatment, for example, two effects can be obtained at the same time: uniform mixing of water and chemicals and uniform light irradiation. . Along with this, the effect of stabilizing the chemical reaction is obtained by making the drug concentration uniform, and the degree of amplification of the reaction rate becomes uniform in each part of the reaction solution by making the absorption of photons uniform, resulting in good light efficiency. is obtained.

[Example] FIG. 1 is a partially cutaway front view of a photochemical reaction device according to an example of the present invention, FIG. 2 is a view of the photochemical reaction device in the direction of arrow A in FIG. 1, and FIG. 3 is a view of FIG. FIG.

In the figure, reference numeral 1 is the reaction vessel main body.

The reaction vessel body 1 has a substantially cylindrical shape, and an ultraviolet lamp 2.3.4 as a rod-shaped light source is provided inside the reaction vessel body 1. These ultraviolet lamps 2.3.4 are cylindrical protective tubes 2a, 3a, and 4a made of transparent quartz, respectively.
They are housed in the reaction container body 1 and are arranged at approximately equal intervals around the central axis C1 of the reaction vessel main body 1, with the longitudinal direction thereof approximately paralleling the central axis C1. Furthermore, flange portions 1a and lb are formed at both ends of the reaction vessel main body 1, respectively, and a mating flange lb is formed on these flange portions 1a and lb.
c and ld are each fixed via a sealing member such as a gasket. and the ultraviolet lamp 2.3.4 and the cA protection tubes 2a, 3a.

Both ends of 4a are inserted into support holes provided in the mating flanges lc and ld, and are supported via sealing members such as packing or bushings.

Note that power is supplied to each of the ultraviolet lamps 2, 3.4 from a power source 5 via a cable 5a.

Further, on the outer periphery near both ends of the reaction vessel main body 1,
A reaction liquid introduction pipe 6 for introducing a reaction liquid and a reaction liquid discharge pipe 7 for discharging the introduced reaction liquid are connected to the reaction container body 1, respectively.

The reaction liquid introduction tube 6 is aligned with the center axis C of the reaction liquid introduction tube 6.
6 is connected to the reaction vessel body 1 by welding or the like so as to pass through a portion between the central axis C1 of the reaction vessel body 1 and the inner peripheral surface of the reaction vessel body 1.

Further, the reaction liquid discharge pipe 7 is also connected to the reaction container body 1 in almost the same way as the reaction liquid introduction pipe 6, but as shown in FIG. 2, it is connected to the arrow in FIG. When viewed from the direction shown, this reaction liquid discharge pipe 7 appears to intersect with the reaction liquid introduction pipe 6.

Furthermore, one end of a drug injection tube 8 for injecting a drug into the reaction liquid introduction tube 6 is connected to the reaction liquid introduction tube 6, and the other end of this drug injection tube 8 is connected to a drug supply device 9. It is connected.

In the above configuration, a reaction liquid such as water is introduced from the reaction liquid introduction pipe 6 as shown by arrow p in the figure, and a reaction liquid such as water is introduced as shown by arrow r.
When a drug is injected from the drug supply device 9 through the drug injection tube 8 as shown in FIG. It is discharged from the discharge pipe 7.

In this case, as shown in FIG. 3, the mixed solution of water and chemicals introduced from the reaction solution introduction pipe 6 forms a helical flow called a cyclone flow, as shown by arrow S. move on. At that time, the ultraviolet lamps 2, 3.4
This helical flow is successively cut by the protective tubes 2a, 3a, and ia containing the . As a result, these protection tubes 2a,
Regular Karman vortices k are generated one after another around 34°4a. As a result, as detailed in the [Effect] section above,
Extremely uniform mixing and uniform light irradiation occur at the same time.

The present inventors have conducted experiments to actually purify pool water using the photochemical reaction device according to the above embodiment, and some of the results are listed below. Note that the power consumption in this case was 172 or less than the conventional one.

Experimental conditions Injected drug: Sodium hypochlorite (available chlorine 12%) Metering pump Injection light source: aoo w Low-pressure mercury lamp (strongest Wavelength: 253.7 mμ) Light irradiation time: 720 hours, cyclic irradiation throughput:
・・・・・・・・・・・・1000m circulation amount・・・・・・
・・・・・・Approx. 60 m'/Hr Contaminated a content...converted to potassium permanganate consumption (turbidity: approx. 1°) [Effects of the invention] As described above in detail, the present invention has the following effects: , a reaction liquid inlet pipe and a reaction liquid discharge pipe are connected to the reaction vessel main body so that the reaction liquid advances in a helical flow within the substantially cylindrical reaction vessel main body, and the reaction proceeds in the helical flow. A rod-shaped light source for light irradiation is arranged within the reaction vessel main body along the longitudinal direction of the reaction vessel main body so as to cut the liquid, and thereby,
The two functions of uniform light irradiation and mixing of the reaction liquid can be effectively obtained at the same time with an extremely simple configuration without using any dynamic mixing means such as a stirring bar.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of a photochemical reaction device according to an embodiment of the present invention, FIG. 2 is a view taken along arrow A of the photochemical reaction device in FIG. 1, and FIG. 3 is a - FIG. DESCRIPTION OF SYMBOLS 1... Reaction container main body, 2, 3.4... Ultraviolet lamp as a light source, 6... Reaction liquid introduction tube, 7... Reaction liquid discharge tube.

Claims (1)

[Scope of Claims] A generally cylindrical reaction vessel body, a rod-shaped light source disposed within the reaction vessel body along the longitudinal direction of the reaction vessel body, and a reaction liquid inside the reaction vessel body. A photochemical reaction device that promotes a reaction by introducing a reaction liquid into the reaction vessel body and irradiating it with light emitted from the light source. A reaction liquid introduction pipe for introducing the reaction liquid and a discharge pipe for discharging the introduced reaction liquid are connected, and the reaction liquid introduction pipe is introduced from the introduction pipe into the reaction vessel main body. The reaction liquid is connected to the reaction vessel main body in such an arrangement that the reaction liquid becomes a helical flow within the reaction vessel main body and proceeds toward the discharge pipe, and further, the light source is connected to the reaction vessel main body in a helical flow within the reaction vessel main body. 1. A photochemical reaction device characterized in that the device is arranged so as to cut off the flow of a reaction solution that moves forward.