NOx Detection Method for Ozone Generator, Ozone Generator, and Gas Detector for Ozone Generator

Abstract

To allow for detecting the presence / absence and concentration of NOx contained in a gas introduced to an ozone generator.SOLUTION: An ozone generator 10 provided herein comprises an ozone generator 40 placed in a flow channel F surrounded by a housing 20 and is configured to allow a source gas containing oxygen and nitrogen to be supplied into the flow channel F from a suction fan 30 through an inlet port 20A. A gas detection unit 60 is provided near an outlet port 20B of the ozone generator 10. The gas detection unit 60 is composed of a material (NOx sample) that reacts with nitrogen oxides (NOx).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an ozone generator, and particularly to the detection of a gas containing ozone.

Background Art

[0002] In an ozone generation device, ozone is generated by discharging or irradiating ultraviolet rays on a raw material gas containing oxygen (such as air), and the gas containing ozone is allowed to flow out into an indoor space, or an object is placed in the flow of the gas containing ozone, thereby enabling sterilization, deodorization, etc.

[0003] Generally, since a gas containing ozone has a strong oxidizing ability, for example, in order to ensure that the ozone concentration in the air does not exceed a certain value depending on the usage environment, an index (guideline) is provided and restricted by the administration or the like. Therefore, ozone checking using an ozone concentration measuring instrument is performed.

[0004] As an ozone concentration measuring instrument, for example, an ozone concentration detection sheet provided with a detection paper that changes color when exposed to ozone gas is known (see Patent Document 1). In this case, a plurality of ozone detection papers with different sensitivities are arranged side by side, and the value of the ozone concentration is marked for each detection paper, and the ozone concentration is read visually.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In an ozone generator using a discharge method, along with ozone generation, nitrogen contained in the source gas chemically reacts with ozone, and oxides (NOx) are secondarily generated. Nitrogen oxides reduce ozone and atomic oxygen, leading to a decrease in ozone concentration and ozone generation efficiency. Further, nitrogen oxides ultimately become stable as dinitrogen pentoxide (N 2 O 5 ), but react with moisture in the air to generate nitric acid (HNO 3 ), which corrodes metals. This may affect metals and resins used as materials for, for example, instruments and utensils placed indoors.

[0007] Therefore, it is required that the ozone generator can detect the presence or absence and concentration of NOx contained in the gas.

Means for Solving the Problem

[0008] A NOx detection method according to one aspect of the present invention is to arrange a sample (hereinafter referred to as a NOx sample) that does not substantially react even when exposed to ozone but reacts when exposed to nitrogen oxides (hereinafter referred to as NOx) so as to be exposed to the gas containing ozone with respect to an ozone generator into which a gas containing nitrogen and oxygen flows and from which a gas containing ozone flows out. It is applicable to an ozone generator using an ultraviolet irradiation method or a discharge method. For example, it can be provided near the gas outlet or along the flow path.

[0009] Alternatively, another aspect of the NOx detection method of the present invention is to arrange a sample (hereinafter referred to as a NOx sample) that does not substantially react even when exposed to ozone but reacts when exposed to nitrogen oxides (hereinafter referred to as NOx) beside an object to be sterilized or deodorized by the gas flowing out of the ozone generator, or to provide it in a space to be sterilized or deodorized.

[0010] The NOx sample can be composed of various materials, and it suffices if it can be confirmed by the five senses of humans such as vision and touch. For example, the NOx sample can be configured to be made of a material whose color or tactile sensation changes when exposed to NOx. Also, the NOx sample can be configured to be made of a material whose hue changes according to the exposure time of the gas containing NOx.

[0011] As the NOx sample, it is possible to apply materials such as metals and resins. For example, the NOx sample is made of ether-based polyurethane rubber, ester-based polyurethane rubber, or vinyl chloride rubber. Also, the NOx sample can be configured to be made of copper or an alloy containing copper, iron or an alloy containing iron, or aluminum.

[0012] An ozone generator which is one aspect of the present invention is an ozone generator into which a raw material gas containing nitrogen and oxygen flows and from which a gas containing ozone flows out, and a sample (hereinafter referred to as an NOx sample) which does not substantially react even when exposed to ozone but reacts when exposed to nitrogen oxides (hereinafter referred to as NOx) is exposed to the gas containing ozone and is provided at a position where an operator can visually observe it. Either an ultraviolet irradiation method or a discharge method can be applied.

[0013] The NOx sample can be configured as a part (such as a gas detection part) of a housing surrounding the flow path of the gas containing ozone. Here, "a part of the housing" means that it is detachably installed on the housing or installed and fixed in advance, and can be included as a component of the ozone generator. Alternatively, it is also possible to configure a gas detector provided with an NOx sample so that it can be attached to and detached from or arranged freely with respect to the ozone generator, and to provide it in a configuration provided in the ozone generator.

[0014] A gas detector for an ozone generator according to one aspect of the present invention includes a sample (hereinafter referred to as a NOx sample) that substantially does not react even when exposed to ozone but reacts when exposed to nitrogen oxides (hereinafter referred to as NOx), and a sample that substantially does not react even when exposed to NOx but reacts when exposed to ozone (hereinafter referred to as an ozone sample). The NOx sample and the ozone sample are arranged at positions where they can be visually compared with each other.

Advantages of the Invention

[0015] According to the present invention, it is possible to detect the presence or absence and concentration of NOx contained in the gas in the ozone generator.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0018] FIG. 1 is a schematic configuration diagram of an ozone generator according to the first embodiment.

[0019] The ozone generator 10 includes a housing 20 and an ozone generation unit 40 disposed in a flow path F surrounded by the housing 20. The raw material gas is supplied from the air supply fan 30 to the flow path F through the inlet 20A. The raw material gas contains oxygen and nitrogen and is composed of, for example, air taken from the atmosphere.

[0020] The ozone generation unit 40 generates ozone by applying a high-frequency high voltage between a pair of electrodes to form a discharge. The generated ozone flows out from the outlet 20B of the housing 20 together with the source gas, and is supplied to the space side such as a room where an object that requires sterilization, deodorization, etc. is installed.

[0021] Near the outlet 20B of the ozone generator 10, a gas detection unit 60 composed of a material (NOx sample) that reacts with nitrogen oxides (NOx) is provided. An operator (or user) can detect whether the gas discharged from the ozone generator 10 contains NOx by checking the gas detection unit 60.

[0022] The gas detection unit 60 is integrally configured here as a part of the housing 20 near the ozone outlet 20B. Also, the gas detection unit 60 is arranged in the flow path F so as to be exposed to the gas containing ozone generated by the ozone generation unit 40. The gas detection unit 60 does not substantially react even when exposed to ozone, but reacts when exposed to NOx.

[0023] The gas detection unit 60 is composed of a material that satisfies the above reaction requirements, and here it is made of metals or resins. As metals, iron, copper, and aluminum can be applied as materials. However, it is also possible to configure it with an alloy containing iron, copper, etc. as the material.

[0024] As resins, polyurethane rubber (ether type), polyurethane rubber (ester type), polyurethane sponge (ether type), polyacetal, and vinyl chloride rubber can be applied as materials. The gas detection unit 60 is appropriately selected from these materials.

[0025] The reaction of the gas detection unit (NOx sample) to NOx varies depending on the material properties of the gas detection unit. When resin materials are exposed to NOx, their color changes, and the hue also changes according to the exposure time of the gas containing NOx. Regarding metal materials, along with the reaction with nitrogen, a color change different from rust (oxidation) caused by oxygen and moisture occurs, and the degree of change increases according to the exposure time of the gas containing NOx.

[0026] On the other hand, in materials such as polyurethane sponge (ether type), a change in viscosity (softening) occurs along with a color change. Also, in metal materials such as aluminum, the gloss changes (the gloss peels off). Furthermore, in the case of vinyl chloride rubber of resin type, almost no color change occurs, but a change occurs in stickiness etc.

[0027] The gas detection unit 60 is configured as a NOx detection unit having reaction characteristics that can be detected visually or by touch such as a color change. The user can know the presence or absence and degree of NOx in the gas flowing out from the ozone generator 10 by visually observing or touching the gas detection unit 60.

[0028] When the ozone generation unit 40 generates ozone by the discharge method, NOx is inevitably generated, but when ozone is generated by the ultraviolet irradiation method, NOx is not generated. However, if abnormal discharge occurs in the flow path F due to some abnormality such as a device failure and NOx is generated, a color change occurs that is completely different from the original color in the gas detection unit 60, or severe peeling of the gloss etc. occurs.

[0029] Therefore, it becomes possible to detect a device failure etc. by checking the state of the gas detection unit 60 that constitutes a part of the housing 20 of the ozone generator 10 with respect to the ozone generation amount as an index. Here, the ozone CT value is generally known as an index indicating the effect of ozone treatment (sterilization, deodorization etc.). The ozone CT value is represented by the product (ppm×min) of the ozone gas concentration and its generation time.

[0030] For example, a reference sample (chart) is prepared using a sample in which color changes or the like appear when the ozone CT value reaches 10,000 or 20,000. By comparing the color change, loss of gloss, stickiness, etc. of the gas detection unit 60 confirmed from a part of the housing 20 of the ozone generator 10 with the reference sample, it becomes possible to detect device failures and the like.

[0031] Note that the number and position of the gas detection unit 60 are arbitrary. A plurality of materials may be used, and different materials such as metals or resins may be used. Also, a plurality of gas detection units of the same material may be arranged side by side. Furthermore, the gas detection unit 60 can be configured to be removable from the ozone generator 10 for replacement.

[0032] Next, the ozone generator according to the second embodiment will be described with reference to FIG. 2. In the second ozone generator, a gas detector composed of a NOx sample is configured to be handled as a single device.

[0033] FIG. 2 is a schematic configuration diagram of the ozone generator according to the second embodiment.

[0034] The gas detector 160 is disposed opposite to the outlet 120B of the housing 120 so as to be exposed to the ozone generated by the ozone generation unit 40 of the ozone generator 100. Here, it is composed of a sample 60' made of one material formed in a rectangular shape. Note that a panel-shaped NOx detector (label) formed by arranging a plurality of samples 60 1 ~60 m may be configured (m represents an integer of 2 or more). The sample does not substantially react when exposed to ozone and reacts when exposed to NOx.

[0035] The gas detector 160 (sample 60' or 60 1 ~60 m ) is composed of a material that satisfies the above reaction requirements, and here it is made of metals or resins. As metals, samples made of iron, copper, or aluminum can be applied. However, it is also possible to configure an alloy containing iron, copper, etc. as a sample.

[0036] As the resins, polyurethane rubber (ether type), polyurethane rubber (ester type), polyurethane sponge (ether type), polyacetal, and vinyl chloride rubber can be applied. Sample 60 1 ~60 m is appropriately selected from these materials, or all samples are installed in the gas detector 160.

[0037] The gas detector 160 (sample 60' or sample 60 1 ~60 m ) is configured as a NOx detection label (detector) having one or more reaction characteristics that can be detected visually such as color change or by touch. The user can know the presence or absence and the degree of NOx in the gas flowing out from the ozone generator 100 by visually observing or touching the sample 60' (60 1 ~60 m ) of the gas detector 160.

[0038] Note that the number and arrangement method of the samples 60' (60 1 ~60 m ) are arbitrary. Different samples of metals or resins may be arranged alternately. Also, a plurality of samples of the same material may be arranged side by side.

[0039] The gas detector 160 is not limited to the configuration of being installed facing the outlet 120B of the housing 120 of the ozone generator 100, and it is also possible to arrange it along the flow path F in the housing 120 rather than the outlet 120B. Alternatively, it may be arranged beside the object to be sterilized or deodorized by the gas flowing out from the ozone generator, or may be provided at an arbitrary position with respect to the space to be sterilized or deodorized.

[0040] Next, the gas detector of the ozone generator according to the third embodiment will be described with reference to FIG. 3. In the third ozone generator, a gas detector is provided in which a sample that reacts when exposed to ozone (hereinafter referred to as an ozone sample) is arranged together with a NOx sample.

[0041] FIG. 3 is a diagram showing a gas detector of the ozone generator in the third embodiment. The gas detector 260 is configured as a panel-shaped gas detector including a NOx sample 60A and an ozone sample 60B. The ozone sample 60B is made of a material that does not substantially react even when exposed to NOx but reacts when exposed to ozone. For example, it may be composed of a sheet-like paper that changes color when the ozone CT value exceeds a predetermined value in a state of being exposed to ozone.

[0042] As the NOx sample 60A, any of the NOx samples shown in the second embodiment may be selectively arranged. The ozone sample 60B can be configured, for example, with a sample using a material that exhibits a color change when the ozone CT value reaches 10,000 or 20,000.

[0043] Similar to the second embodiment, a plurality of samples 60 1 ~60 m may be arranged for the gas detector 260. Also, as the ozone sample 60B, a plurality of samples that react when exposed to ozone may be used.

[0044] The operator visually checks the gas detector 260 to confirm the presence or absence of discoloration of the ozone sample 60B. At the same time, the operator examines the presence or absence of changes such as the color tone of the NOx sample 60A in a state where the ozone sample 60B does not show a reaction. If the NOx sample 60A is reacting, it becomes possible to detect the occurrence of abnormalities in NOx.

[0045] The gas detectors 160 and 260 do not necessarily have to be configured to be pre-mounted on the ozone generator. The operator may bring a sheet-like gas detector (gas detection label) during equipment inspection or the like, place it beside the ozone generator, and detect the presence or absence of NOx generation. Also, instead of configuring it as a gas detector, each sample may be prepared separately individually, and NOx may be detected. In this case, a sample that reacts with ozone may also be prepared separately individually so that it can be compared with the NOx detection sample.

Example

[0046] The NOx samples, which are examples, will be described below.

[0047] Samples 1 to 5 are each composed of SPCC (cold-rolled steel sheet, unpainted), copper, aluminum (SP raster), polyurethane rubber (ether type), and polyurethane rubber (ester type), which are formed into a rectangular shape.

[0048] A general discharge-type ozone generator was prepared, and an ultraviolet irradiation-type ozone generator (ARV-O3GU manufactured by Oak Manufacturing Co., Ltd.) was prepared. Each material was placed near the gas outlet. Then, the states of each of Samples 1 to 5 when the CT value reached a predetermined value were compared.

[0049] In the case of the unpainted SPCC with a gray color tone of Sample 1, at an ozone CT value of 80,000, discoloration (blackening) of the color was revealed in the discharge-type ozone generator. Furthermore, when the ozone CT value reached 600,000, the whole became black. On the other hand, in the ultraviolet irradiation-type ozone generator, no substantial change in color was confirmed.

[0050] In the case of the copper of Sample 2, at an ozone CT value of 80,000, discoloration (fading) of the color was revealed in the discharge-type ozone generator. Furthermore, when the ozone CT value reached 600,000, the whole became blue-green. On the other hand, in the ultraviolet irradiation-type ozone generator, no substantial change in color due to factors other than rust was confirmed.

[0051] In the case of the aluminum of Sample 3, at an ozone CT value of 120,000, loss of luster (fading) was revealed in the discharge-type ozone generator. On the other hand, in the ultraviolet irradiation-type ozone generator, no substantial loss of luster was confirmed.

[0052] In the case of the transparent ether-type polyurethane rubber of Sample 4, at an ozone CT value of 40,000, discoloration (yellow-green) of the color was revealed in the discharge-type ozone generator. On the other hand, in the ultraviolet irradiation-type ozone generator, no substantial change in color was confirmed.

[0053] In the case of the transparent ester-based polyurethane rubber of Sample 5, at an ozone CT value of 40,000, discoloration (yellowish green) became apparent in the ozone generator using the discharge method. On the other hand, in the ozone generator using the ultraviolet irradiation method, no substantial change in color was confirmed.

[0054] From the above results, it was confirmed that Samples 1 to 5 do not react even when exposed to a gas containing ozone, while they react to a gas containing NOx.

Explanation of Signs

[0055] 10, 100 Ozone generator 40 Ozone generation unit 60 Gas detector 60’, 60 1 ~60 m NOx sample 60A NOx sample 60B Ozone sample 160, 260 Gas detector

Claims

Claim 1: For an ozone generator into which a gas containing nitrogen and oxygen flows, generates ozone by an ultraviolet irradiation method, and discharges a gas containing ozone, a method for detecting NOx in an ozone generator, wherein a sample (hereinafter referred to as a NOx sample) that does not substantially react even when exposed to ozone but reacts when exposed to nitrogen oxides (hereinafter referred to as NOx) is arranged to be exposed to the gas containing ozone. The method for detecting NOx in an ozone generator according to claim 1, characterized in that the NOx sample includes a sample made of a resin whose hue changes according to the exposure time of the gas containing NOx and a sample made of a resin whose tactile sensation changes when exposed to NOx. Claim 2: The method for detecting NOx in an ozone generator according to claim 1, characterized in that the NOx sample includes a sample made of an ether-based polyurethane rubber, an ester-based polyurethane rubber, or a vinyl chloride rubber. Claim 3: The method for detecting NOx in an ozone generator according to claim 1, characterized in that the NOx sample includes a sample made of copper or an alloy containing copper, iron or an alloy containing iron, or aluminum.

Images