JP7539273B2 - Ozone generator and method for generating ozone - Google Patents

Description

The present invention relates to an ozone generator equipped with an excimer lamp.

In an ozone generator equipped with an ultraviolet irradiation means such as an excimer lamp, ozone is generated by irradiating an oxygen-containing gas or liquid with ultraviolet light, and then released outside the device. Ozone has a strong oxidizing effect, so it can be used for sterilization, deodorization, and other processes.

In order to generate ozone efficiently, an ozone generator is known in which an excimer lamp is placed inside a flow tube extending in one direction and the flow rate of the raw material gas inside the flow tube is adjusted (see Patent Document 1). In this device, gas is supplied to the flow tube through an axial fan so that the gas flow inside the flow tube is uniform.

JP 2017-43513 A

The gas or liquid that is irradiated with ultraviolet light may contain viruses, organic matter, or other factors that hinder ozone generation. In particular, in the case of excimer lamps that emit ultraviolet light in the wavelength range of 200 nm or less (such as 172 nm), the ultraviolet light is attenuated and has a short reach, making it difficult to effectively generate ozone in the gas or liquid flowing around the excimer lamp.

Therefore, in an ozone generator that has an excimer lamp in the flow path, it is necessary to remove organic matter and generate ozone effectively.

The ozone generator according to one aspect of the present invention includes a flow path through which an oxygen-containing fluid to be irradiated with ultraviolet light flows, and an ultraviolet irradiation means disposed in the flow path. For example, the ultraviolet irradiation means can emit a first ultraviolet light having a peak wavelength of 200 nm or less, and a second ultraviolet light having a peak wavelength in a longer wavelength range than the first ultraviolet light.

The ultraviolet irradiation means of the present invention is an excimer lamp, and for example, the excimer lamp has a discharge vessel in which a gas that emits the first ultraviolet light is sealed, and has a phosphor that receives the first ultraviolet light and emits the second ultraviolet light.

In the present invention, the excimer lamp irradiates the fluid flowing around the lamp from the upstream side to the downstream side of the flow path with the second ultraviolet light before the first ultraviolet light. Various configurations are possible for irradiating the fluid flowing around the lamp with the first ultraviolet light before the second ultraviolet light.

For example, if the ratio of ultraviolet intensity to the reach of the second ultraviolet light is greater than that of the first ultraviolet light for the same reach, the second ultraviolet light can be irradiated onto the fluid at a point farther away from the lamp surface, resulting in irradiation further ahead than the first ultraviolet light.

On the other hand, it is also possible for the excimer lamp to selectively irradiate ultraviolet light. When the flow path forms a fluid flow along one direction due to the arrangement of the flow path tube, etc., the excimer lamp can irradiate the second ultraviolet light to the fluid upstream of the lamp midpoint along the flow path, and irradiate the first ultraviolet light to the fluid downstream of the lamp midpoint.

For example, an excimer lamp can be arranged so that the lamp axis is aligned along the flow path, or so that the lamp axis is aligned perpendicular to the flow path. For example, the excimer lamp can be configured so that a phosphor that receives the first ultraviolet light and emits the second ultraviolet light is provided in the upstream portion of the lamp center position with respect to the discharge vessel.

The ozone generator can be configured such that a fluid supply unit, such as a blower, that supplies fluid to the flow path is located upstream of the excimer lamp in the flow path. In this case, the fluid supply unit can form a non-uniform flow at least around the excimer lamp.

The ozone generation method according to one aspect of the present invention is an ozone generation method in which an excimer lamp is disposed in a flow path through which an oxygen-containing fluid to be irradiated with ultraviolet light flows, and the excimer lamp irradiates the fluid with first ultraviolet light having a peak wavelength of 200 nm or less and second ultraviolet light having a peak wavelength in a longer wavelength range than the first ultraviolet light, and the second ultraviolet light is irradiated to the fluid flowing around the lamp from the upstream side to the downstream side of the flow path before the first ultraviolet light.

According to the present invention, in an ozone generator in which an excimer lamp is placed in a flow path, organic matter and the like can be removed and ozone can be generated effectively.

1 is a schematic configuration diagram of an ozone generator according to a first embodiment. FIG. FIG. 2 is a schematic internal configuration diagram of an excimer lamp. FIG. 1 is a schematic diagram of an ozone generator according to a second embodiment.

The ozone generator of this embodiment will be described below with reference to the drawings. Figure 2 is a schematic diagram of the internal configuration of the excimer lamp.

Figure 1 is a schematic diagram of an ozone generator according to a first embodiment.

The ozone generator 10 includes an excimer lamp 20, a flow tube 30, and a blower 40 in a casing (not shown). When gas containing oxygen flows into one end (hereinafter referred to as the inlet) 30A of the flow tube 30, ozone is generated by ultraviolet irradiation from the excimer lamp 20. The gas containing ozone flows out from the other end (hereinafter referred to as the outlet) 30B of the flow tube 30 and is released outside the device. This makes it possible to perform sterilization and disinfection treatments outside the device.

Here, the flow passage tube 30 is composed of a tubular member extending in one direction, and the excimer lamp 20 is arranged coaxially with the flow passage tube 30 so that its lamp axis E is along the direction of gas flow. The excimer lamp 20 emits ultraviolet light (first ultraviolet light/first ultraviolet light) having a peak wavelength of 200 nm or less (e.g., 172 nm), and also emits ultraviolet light (second ultraviolet light/second ultraviolet light) having a peak wavelength in a longer wavelength range (e.g., 274 nm). An axial fan type blower 40 is arranged coaxially with the flow passage tube 30 at the inlet 30A of the flow passage tube 30.

As shown in FIG. 2, the excimer lamp 20 includes a discharge tube (discharge container) 22 in which a rare gas is sealed. A foil-shaped inner electrode 24 is provided inside the discharge tube 22 and is covered with a columnar dielectric (such as quartz glass). An outer electrode 26 is provided on the outer surface 22S1 of the discharge tube 22. The outer electrode 26 here is composed of a number of strip-shaped electrodes extending along the lamp axis E, and is arranged at predetermined intervals in the circumferential direction of the discharge tube 22.

The inner surface 22S of the discharge tube 22 is partially coated with phosphor M. Here, phosphor M is coated only on the upstream half of the inner surface 22S, separated by the lamp center line C, which represents the middle position of the excimer lamp 20 with respect to the tube axis of the flow path tube 30. However, in FIG. 2, the thickness of phosphor M is exaggerated.

When a voltage is applied to the inner electrode 24 and outer electrode 26 of the excimer lamp 20, ultraviolet light (excimer light) with a peak wavelength of 172 nm is emitted. When phosphor M receives ultraviolet light with a peak wavelength of 172 nm, it emits ultraviolet light of 274 nm toward the outside of the lamp. Therefore, ultraviolet light (ultraviolet light) with a peak wavelength of 172 nm is emitted in the downstream half of the excimer lamp 20 from the lamp center line C, while ultraviolet light (ultraviolet light) with a peak wavelength of 274 nm is emitted toward the outside of the lamp in the upstream half of the lamp center line C.

Viruses, organic matter, etc. absorb ultraviolet light with a wavelength in the range of 200 to 300 nm, and their decomposition is promoted. Therefore, organic matter contained in the gas flowing into the flow tube 30 is first decomposed by the ultraviolet light with a peak wavelength of 274 nm emitted from the excimer lamp 20. Note that ultraviolet light with a peak wavelength of 274 nm is suitable for decomposing organic matter, but ultraviolet light with a peak wavelength of 228 nm or 264 nm, for example, may also be used. Furthermore, ultraviolet light with a peak wavelength of 320 nm or 344 nm can also be used depending on the type of organic matter contained in the gas and the wavelength at which the organic matter is decomposed. Then, the gas from which the organic matter has been decomposed is irradiated with ultraviolet light with a wavelength of 172 nm emitted from the excimer lamp 20, generating ozone.

Here, the 172 nm ultraviolet light has a smaller ultraviolet light intensity ratio than the 274 nm ultraviolet light. The ultraviolet light intensity ratio is expressed as the attenuation ratio at the point where the ultraviolet light reaches as it attenuates as it travels. The 274 nm ultraviolet light emitted from the upstream half of the excimer lamp 20 travels to the tube wall 30S of the flow path tube 30 while maintaining almost the same light intensity. On the other hand, the reach of the 172 nm ultraviolet light is limited to a predetermined distance d from the surface 20S of the excimer lamp 20.

In FIG. 1, the 274 nm UV irradiation space and the 172 nm UV irradiation space are indicated by the symbols E1 and E2, respectively. By irradiating the entire gas flowing into the flow tube 30 with 274 nm UV rays upstream of the lamp, organic matter contained in the flowing gas can be effectively decomposed.

The blower 40, located upstream of the excimer lamp 20, creates a non-uniform gas flow in the flow tube 30. It creates a complex flow state in which the velocity in the flow direction cannot be expressed as a time average, and also creates a three-dimensional flow such as a swirling flow around the excimer lamp 20. Incidentally, the arrows in Figure 1 simply indicate the gas flow from the upstream side to the downstream side of the flow tube 30.

Therefore, around the excimer lamp 20, the gas near the surface 20S of the excimer lamp 20 and the gas near the tube wall 30S of the flow path tube 30 mix, and a homogeneous gas with no bias in the amount of ozone generated flows out from the outlet 30B. The diameter R of the flow path tube 30 and the air volume of the blower 40 are determined so that such a non-uniform gas flow can be formed inside the flow path tube 30.

As described above, according to the first embodiment, in the ozone generator 10, the excimer lamp 20 is disposed in the flow path tube 30, and the blower 40 is disposed at the inlet 30A of the flow path tube 30. The excimer lamp 20 radiates ultraviolet light of 274 nm in the upstream portion of the lamp, and first decomposes impurities such as organic matter in the gas that has flowed into the flow path tube 30. Then, the excimer lamp 20 radiates ultraviolet light of 172 nm in the downstream portion of the lamp toward gas without impurities, and can effectively generate ozone.

The excimer lamp 20 emits ultraviolet light from phosphor M for the purpose of decomposing organic matter, but phosphor M does not need to be applied to the entire upstream half of the lamp; it may be applied partially to the uncoated portion, or may be applied in a dispersed manner. In this case, since 274 nm ultraviolet light reaches farther, the gas on the upstream side of the lamp that flows into the flow tube 30 is first irradiated with 274 nm ultraviolet light, and then irradiated with 172 nm ultraviolet light. Similarly, phosphor M may be applied partially to the downstream portion of the lamp. Also, phosphors may be provided to the excimer lamp by a method other than coating.

The flow path pipe 30 can be constructed of something other than a straight tubular member, and the excimer lamp 20 can be placed in a flow path without a flow path pipe. The ozone generator 10 is not limited to a unit configuration, and can be incorporated into a sterilization treatment device, a deodorization device, an air purifier, etc. It is also possible to generate ozone from liquids that contain particles or liquids other than gas.

Next, a second embodiment of the ozone generator will be described with reference to FIG. 3. In the second embodiment, the excimer lamp is arranged in a direction perpendicular to the axis of the flow tube.

Figure 3 is a schematic diagram of an ozone generator according to a second embodiment.

The ozone generator 10' comprises an excimer lamp 20', a flow passage tube 30', and a blower 40', and the blower 40' is arranged coaxially with the inlet 30'A of the flow passage tube 30'. The excimer lamp 20' is arranged in the flow passage tube 30' so that the lamp axis E is aligned perpendicular to the tube axis of the flow passage tube 30'. Therefore, the lamp center line C of the excimer lamp 20' is on the same line as the lamp axis E.

The upstream half of the inner surface of the discharge tube 22' of the excimer lamp 20' is coated with a phosphor. Therefore, in the excimer lamp 20', 274 nm ultraviolet light is emitted from the upstream half, and 172 nm ultraviolet light is emitted from the downstream half, with the lamp center line C as the boundary.

As in the first embodiment, the entire gas flowing into the flow tube 30' is irradiated with 274 nm ultraviolet light, thereby effectively decomposing organic matter. In addition, the blower 40' creates a three-dimensional flow inside the flow tube 30', so that the gas from which the organic matter has been decomposed is effectively irradiated with 172 nm ultraviolet light, and a homogeneous gas with no bias in the amount of ozone generated flows out from the outlet 30'B.

Here, the excimer lamp 20 is configured as a single unit, but a configuration in which multiple excimer lamps are arranged may also be used. The ultraviolet light (excimer light) used by the excimer lamp 20 to generate ozone may be ultraviolet light with a peak wavelength other than 172 nm, as long as it is equal to or less than 200 nm, which is the wavelength range of oxygen absorption characteristics. In addition, ultraviolet light emitted to decompose organic matter, etc. may also be ultraviolet light with a peak wavelength other than 274 nm, and it is sufficient to irradiate ultraviolet light with a wavelength range larger than that of the ultraviolet light from the excimer lamp 20, for example, in the range of 200 to 300 nm.

10 Ozone generator 20 Excimer lamp 30 Flow path pipe 40 Blower (fluid supply unit)

Claims (9)

a flow path through which a fluid containing oxygen to be irradiated with ultraviolet light flows in one direction ;
an excimer lamp having a discharge vessel and arranged such that a lamp axis is aligned with the flow path;
the excimer lamp is capable of emitting a first ultraviolet light having a peak wavelength of 200 nm or less and a second ultraviolet light having a peak wavelength in a longer wavelength range than the first ultraviolet light;
an excimer lamp that radiates the second ultraviolet light from the discharge vessel toward a fluid upstream of a middle position of the lamp along the flow path, and radiates the first ultraviolet light from the discharge vessel toward a fluid downstream of the middle position of the lamp . 2. The ozone generator according to claim 1 , wherein the first ultraviolet light has a peak wavelength of 172 nm . 2. The ozone generator according to claim 1 , wherein the second ultraviolet light has a peak wavelength of any one of 228 nm, 264 nm, 320 nm, and 344 nm. A gas for emitting the first ultraviolet light by discharge is sealed in the discharge vessel,
2. The ozone generating device according to claim 1 , wherein the discharge vessel has, in a portion upstream from a center position of the lamp, a phosphor that receives the first ultraviolet light and emits the second ultraviolet light . a flow path through which a fluid containing oxygen to be irradiated with ultraviolet light flows;
An ultraviolet ray irradiation means is disposed in the flow path,
the ultraviolet irradiation means is capable of emitting a first ultraviolet light having a peak wavelength of 200 nm or less and a second ultraviolet light having a peak wavelength in a wavelength range longer than that of the first ultraviolet light,
The ultraviolet irradiating means irradiates the fluid flowing around the lamp from the upstream side to the downstream side of the flow path with the second ultraviolet light before irradiating the first ultraviolet light,
the ultraviolet ray irradiating means is an excimer lamp,
The flow path forms a flow of a fluid along one direction,
the excimer lamp irradiates the second ultraviolet light onto a fluid upstream of a lamp intermediate position along the flow path, and irradiates the first ultraviolet light onto a fluid downstream of the lamp intermediate position along the flow path;
1. An ozone generating device, wherein the excimer lamp is disposed so that the lamp axis is aligned in a direction perpendicular to the flow path. a fluid supply unit arranged upstream of the excimer lamp in the flow path and supplying a fluid to the flow path,
6. The ozone generating device according to claim 2, wherein the fluid supplying section forms a non-uniform flow at least around the excimer lamp. a flow path through which a fluid containing oxygen to be irradiated with ultraviolet light flows;
An ultraviolet ray irradiation means is disposed in the flow path,
the ultraviolet irradiation means is capable of emitting a first ultraviolet light having a peak wavelength of 200 nm or less and a second ultraviolet light having a peak wavelength in a wavelength range longer than that of the first ultraviolet light,
The ultraviolet irradiating means irradiates the fluid flowing around the lamp from the upstream side to the downstream side of the flow path with the second ultraviolet light before irradiating the first ultraviolet light,
the ultraviolet ray irradiating means is an excimer lamp,
the excimer lamp has a discharge vessel in which a gas for emitting the first ultraviolet light by discharge is sealed,
13. An ozone generating apparatus, wherein said discharge vessel has, in an upstream portion from a central position of the lamp, a phosphor which receives said first ultraviolet light and emits said second ultraviolet light. An ozone generator according to any one of claims 1 to 7, characterized in that the ultraviolet intensity ratio of the second ultraviolet light to the reach distance is greater than that of the first ultraviolet light. An excimer lamp having a discharge vessel is disposed with its lamp axis aligned along a flow path in which an oxygen-containing fluid to be irradiated with ultraviolet light flows in one direction ;
A method for generating ozone, comprising irradiating a fluid with a first ultraviolet light having a peak wavelength of 200 nm or less and a second ultraviolet light having a peak wavelength in a wavelength range longer than that of the first ultraviolet light from the excimer lamp ,
The ozone generating method comprises radiating the second ultraviolet light from the discharge vessel toward a fluid upstream of a lamp intermediate position along the flow path, and radiating the first ultraviolet light from the discharge vessel toward a fluid downstream of the lamp intermediate position.

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