JP2600887B2 - UV irradiation device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet irradiation apparatus, and more particularly, to an ultraviolet irradiation apparatus that oxidizes organic substances in clear water such as pure water and ultrapure water.

[Conventional technology]

Recently, along with the improvement in the degree of integration of semiconductors, the quality of pure water and ultrapure water used for cleaning water has been improved year by year.Especially, even if trace amounts of organic substances dissolved in Removal of organic matter is desired to reduce yield.

One of the methods for removing the organic matter is to irradiate the water to be treated with ultraviolet rays to generate hydroxyl radicals and ozone in the water to be treated and to decompose the organic matter in the water to be treated with these oxidizing powers. There is a method of collecting pure water.

The collected ultrapure water for cleaning is mainly used as cleaning water for ultraprecision circuits such as semiconductors.

Conventional ultraviolet irradiation apparatuses include an extrusion flow type and a perfect mixing type (JP-A-56-11883, JP-A-61-16).
No. 129). This extrusion flow type ultraviolet irradiation device
As shown in FIG. 2, a plurality of ultraviolet lamps 22, 22,... Are provided in a cylindrical container 20, and water to be treated is supplied to the cylindrical container.
Water is injected through a water inlet 24 provided at one end of the container 20, and is oxidized in the container 20 by ultraviolet lamps 22, 22,. Also,
The treated water is collected from a drain port 26 provided at the other end of the container 20.

In addition, although not shown, in the conventional complete mixing type ultraviolet irradiation apparatus, an ultraviolet lamp is provided in the container, and the water to be treated in the container is oxidized by the ultraviolet lamp provided in the container while stirring the water to be treated. There is a complete mixing type ultraviolet irradiation device for collecting water.

[Problems to be solved by the invention]

However, in the above-mentioned conventional extrusion flow type ultraviolet irradiation apparatus, the ultraviolet ray reaching distance for oxidizing the water to be treated with ultraviolet rays emitted from the ultraviolet lamp is as short as 5 to 10 mm.
Therefore, although the water to be treated flowing near the ultraviolet lamp is easily oxidized, the water to be treated flowing on the inner wall surface of the container may not be oxidized. Further, in order to oxidize the water to be treated flowing on the inner wall surface of the container, a high output is required for the ultraviolet lamp. However, in this case, a large amount of hydroxyl radicals and ozone generated in the vicinity of the ultraviolet lamp have a disadvantage that they are self-decomposed and disappear because organic substances in the water to be treated near the ultraviolet lamp have already been oxidized. Also, if the residence time of the water to be treated is lengthened to completely oxidize the water to be treated, the flow of the water to be treated in the vessel becomes a completely laminar flow, and the organic matter in the water to be treated flowing on the inner wall surface of the vessel is oxidized. It may not be done.

In this case, even if the ultraviolet lamp has a high output, the water to be treated flowing on the inner wall surface of the container is not oxidized.

In addition, in the conventional complete-mixing type ultraviolet irradiation apparatus, the reaction rate of the ultraviolet oxidation of the organic substance is high when the concentration of the organic substance in the water to be treated is high, and is low when the concentration of the organic substance is low. Therefore, in the stirring tank in which the flow is completely mixed, the water to be treated in the tank is diluted to lower the concentration of organic substances, so that there is a disadvantage that the oxidation efficiency is reduced.

The present invention has been made in view of such circumstances, and has as its object to provide an ultraviolet irradiation apparatus with improved oxidation efficiency of water to be treated.

[Means to solve the problem]

The present invention provides, in order to achieve the above-mentioned object, an ultraviolet irradiation apparatus in which water to be treated is irradiated with ultraviolet rays emitted from an ultraviolet lamp to oxidize organic substances in the water to be treated,
A cylindrical container, a perforated inner cylinder provided inside the cylindrical container and forming a water passage between the container, and an isolation wall for dividing the perforated inner cylinder into a plurality of chambers in the axial direction, It comprises a porous suction / drainage pipe provided substantially at the center of the perforated inner cylinder, and a plurality of cylindrical ultraviolet lamps provided around the perspiration / drainage pipe along the axial direction of the perforated inner cylinder. The water to be treated which has flowed out of the suction / drain pipe into the perforated inner cylinder flows through the water passage again into the adjacent chamber of the perforated inner pipe, and is discharged from the suction / drain pipe.

[Action]

According to the present invention, the to-be-processed water flowing out of the perforated suction / drain pipe provided substantially at the center of the perforated inner cylinder collides with or passes through a plurality of ultraviolet lamps provided around the perimeter of the suction / drain pipe. It flows out to the inner cylinder. The water to be treated that has flowed out flows again into the adjacent chamber of the perforated inner cylinder through a water passage provided between the container and the perforated inner cylinder. The inflowing water to be treated again collides with or passes through the plurality of ultraviolet lamps, flows into the suction / drainage pipe, and is discharged. By this action,
The water to be treated is efficiently oxidized, and ultrapure water for cleaning is collected.

〔Example〕

Hereinafter, preferred embodiments of the ultraviolet irradiation apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

1 (A) and 1 (B) show an embodiment of the ultraviolet irradiation apparatus according to the present invention.

The container 10 is formed in a cylindrical shape, and a perforated inner cylinder 18 is provided inside the container 10. This inner cylinder with perforations 18 has many holes 18
A, 18A ... are formed. Further, a water-absorbing porous tube 12 and a drainage porous tube 14 are provided at the axial center of the container 10. The water-absorbing porous tube 12 and the drainage porous tube 14 are formed with a large number of holes 12A, 12A, and holes 14A, 14A, respectively. A plurality of cylindrical ultraviolet lamps 16 are provided in the container 10 in the axial direction. In addition, water absorption porous tube
In order to separate the perforated pipe 12 from the drainage pipe 14, a separating wall 19 is provided in the perforated inner cylinder 18, and defines a first purification tank 10A and a second purification tank 10B.

Next, the operation of the ultraviolet irradiation apparatus configured as described above will be described.

First, the water to be treated is injected from the inlet 13 of the porous tube 12 for water absorption, and is radially discharged from the holes 12A, 12A,... Formed in the porous tube 12 for water absorption toward the first purification tank 10A. The discharged water to be treated is uniformly oxidized by colliding with or passing through the cylindrical ultraviolet lamps 16 provided in parallel with the water-absorbing porous tube 12. The water to be treated oxidized in the first septic tank 10A is supplied to the holes 18A, 1
Spilled out of 8A ... The treated water that has flowed out passes through a water passage 18B provided between the container 10 and the perforated inner cylinder 18,
From the holes 18A, 18A,... Formed in the perforated inner cylinder 18, the second septic tank
Flow into 10B. The inflowing water to be treated is uniformly oxidized again by colliding with or passing through the cylindrical ultraviolet lamps 16. The oxidized ultrapure water is supplied to a large number of holes 14A, 14A ...
From the extraction outlet 15 and is collected. This makes it possible to efficiently and evenly oxidize the water to be treated and to collect ultrapure water for cleaning.

FIG. 3 is an explanatory diagram showing a comparative example of the residence time (min) in the concentration of organic matter (μg /) in the water to be treated between the ultraviolet irradiation apparatus of the present invention and the conventional ultraviolet irradiation apparatus. According to this, when the concentration of organic matter in the water to be treated is 50 (μg /), the residence time is about 4.5 (min) when the apparatus of the present invention is used, but about 5 (min) when the extrusion flow type of the conventional apparatus is used. .
5 (min) and 7.5 (mi)
n) and the residence time becomes longer. Therefore, when the water to be treated having the same concentration is oxidized, the apparatus of the present invention can be oxidized in a shorter time and collected as ultrapure water for cleaning. That is, it is possible to significantly save energy consumption.

In the above embodiment, a perforated tube was used as the water-permeable inner cylinder. However, the first purification tank uses a filter material or a film material having a relatively large water resistance in at least one of the second purification tanks.
The water to be treated may flow in a pressurized state. Similarly, a water-absorbing tube and a drainage tube formed of a porous material are used, but a tube made of a water-permeable material such as a ceramic tube may be used.

According to the above configuration, the inflow and outflow of the liquid are performed evenly, and the radial flow of the liquid in the container can be easily created. In the above embodiment, the septic tank was divided into two parts, but may be divided into multiple stages according to the quality of the water to be treated.

〔The invention's effect〕

As described above, according to the ultraviolet irradiation apparatus according to the present invention, the water to be treated is evenly colliding with or passed through the ultraviolet lamp, so that the water to be treated is efficiently oxidized evenly, and the cleaning water Pure water can be collected.
Also, energy consumption can be greatly reduced.

[Brief description of the drawings]

1 (A) and 1 (B) are a plan view showing an embodiment of an ultraviolet irradiation apparatus according to the present invention, a cross-sectional view including a partial cross section, and FIG.
FIG. 3 is a side view showing one embodiment of an ultraviolet irradiation apparatus according to a conventional example, and FIG. 3 is an explanatory view showing a comparison of the residence time in the concentration of organic substances in the water to be treated between the apparatus of the present invention and the conventional apparatus. is there. 10 ... container, 10A ... first septic tank, 10B ... second septic tank,
12: Perforated tube for water absorption, 14: Perforated tube for drainage, 16: UV lamp, 18: Inner tube with perforation, 19: Separation wall.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kazuhiko Takino Examiner, Hitachi Plant Construction Co., Ltd. 1-11-1 Uchikanda, Chiyoda-ku, Tokyo Yoshihisa Seki

Claims (1)

(57) [Claims] 1. An ultraviolet irradiation apparatus for irradiating water to be treated with ultraviolet rays emitted from an ultraviolet lamp to oxidize organic substances in the water to be treated, wherein the apparatus is provided inside a cylindrical container and a cylindrical container. A perforated inner cylinder that forms a water passage between the container and a container; an isolation wall that divides the perforated inner cylinder into a plurality of chambers in an axial direction; and a perforated provided substantially in the center of the perforated inner cylinder. Water-drainage pipe, and a plurality of cylindrical ultraviolet lamps provided around the water-suction and drainage pipe along the axial direction of the perforated inner cylinder; An ultraviolet irradiation device characterized in that the ultraviolet irradiation device flows into the chamber adjacent to the perforated inner cylinder again through the water passage and is discharged from the suction / drain pipe.