JPH09131514A - Harmful gas removing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase decontamination ability per one unit of a harmful gas removing device only by ensuring a small installation space on the ground without almost limiting the installation place. SOLUTION: This harmful gas removing device is constituted so as to adsorb and capture pollutants such as NOx, SOx contained in the environmental air on a photocatalyst by utilizing the contact reaction of the air with the photocatalyst activated by receiving the irradiation of solar light to oxidize. In such a case, plural numbers of phtocatalytic panels 3 each formed by sticking a photocatalytic sheet consisting essentially of titanium dioxide to both surfaces of a substrate are suspended to be supported from the branched supporting arms 2 of a support 1 in the same way as branches and leaves of a tree and as a cleaning means of the photocatalytic panel 3, a sprinkling nozzle 4 for sprinkling a cleaning water toward the photocatalytic sheets is provided on the top part of the support 1. Polluted air is purified under the irradiation of solar light in a day time and the decontamination ability of the photocatalyst is recovered by sprinkling the cleaning water regularly to wash out oxidized products of the pollutants adsorbed to the photocatalyst.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a harmful gas removing device for preventing air pollution in areas along main roads in urban areas where automobile traffic is heavy.

[0002]

2. Description of the Related Art In an area along a main road in an urban area where there is a large amount of automobile traffic, N contained in the exhaust gas of automobiles
O _X, has become a pollution of the ambient air is a social problem due to SO _X, but is now doing the total amount regulation of air pollutants in such exhaust gas Control Act, No reality can not clear people in environmental standards Is the current situation.

On the other hand, recently, as one of the measures for environmental air purification, low concentrations of NO _x and SO contained in the atmosphere have been introduced.
Research and development of a technique for removing contaminants such as _X using a photocatalyst are under way, for example, Japanese Patent No. 161330.
No. 1 has a wavelength of 300 to 400 nm in a porous photocatalyst layer obtained by adding activated carbon to titanium dioxide, which is a typical photocatalyst.
To activate the photocatalyst by irradiation of near-ultraviolet light, oxidation of pollutants such as NO _X, SO _X by contact reaction with the surrounding atmosphere, a photocatalyst for removing by adsorption is disclosed. That is, when titanium dioxide is irradiated with near-ultraviolet rays, active oxygen species are generated on the surface of the catalyst layer, NO _x is oxidized to nitric acid through nitrogen dioxide, and the oxidation product is adsorbed and captured in the form of nitrate ion. ..

Further, a photocatalyst containing titanium dioxide as a main component is formed into a thin sheet or panel having a thickness of 1 mm or less, which is used inside a soundproof wall of an automobile road or at an intersection of a main road in an urban area. Japanese Patent Laid-Open No. 6-315614 proposes a structure which is laid on the outer wall of a building to remove pollutants in the ambient air.

[0005]

By the way, in order to purify the ambient air using the photocatalyst panel containing titanium dioxide as a main component as described above, a photocatalyst panel having a huge area is required. On this point, a large area of soundproof walls installed on both sides of a motorway (highway) can be used, but even if the outer wall of a building is used along a main road in a city area, at an intersection, etc. Since it is difficult to secure a sufficient laying area due to various restrictions, a sufficient decontamination effect cannot be expected.

The present invention has been made in view of the above points, and the decontamination ability per unit can be increased by securing a small installation space on the ground with almost no restrictions on the installation location. An object of the present invention is to provide a harmful gas removing device that is skillfully configured so as to be achieved.

[0007]

In order to achieve the above object, the harmful gas removing apparatus of the present invention comprises a photocatalyst panel in which a photocatalyst containing titanium dioxide as a main component is formed into a sheet and adhered to a substrate. It will be installed in the same way as the branches and leaves of trees around the columns that stand outdoors. Further, according to the present invention, it is possible to specifically configure the following configurations or additional requirements based on the above configuration.

1) A large number of support arms that are vertically branched in multiple stages are provided on a column, and the photocatalyst panel is suspended and supported by the support arms. 2) A photocatalyst sheet is attached to the front and back sides of the substrate of the photocatalyst panel. 3) Use a flexible plastic sheet for the substrate. 4) The photocatalyst panel is provided with a cleaning means for spraying the cleaning water supplied from the water supply source to elute and eliminate the oxidation products of the contaminants adsorbed and captured by the photocatalyst.

5) As the above-mentioned cleaning means, a spray nozzle for spraying cleaning water toward the photocatalyst sheet group is provided at the top of the column. 6) As a cleaning means, a water spray nozzle and a cleaning drainage receiver are provided above and below the substrate for each photocatalyst panel. 7) The harmful gas removing devices having the above-mentioned configuration are installed side by side along a main road in an urban area where there is a large amount of automobile traffic.

According to the above structure, a large area can be secured by mounting a large number of photocatalyst panels on the pillars by occupying a small installation space for standing the pillars on the ground. This increases the decontamination capacity per unit. Therefore, by arranging the harmful gas removing device with such a configuration in a buffer zone such as a green belt along a main road in an urban area and planting a roadside tree, it is possible to effectively remove the air polluted by the exhaust gas of an automobile. It can be purified to protect the environment.

In this case, a large number of support arms branching from the support columns are provided to attach a large number of photocatalyst panels, and if the photocatalyst sheets are attached to both front and back surfaces of each panel, the decontamination area is also doubled. To do. Further, by attaching the thin-film photocatalyst sheet to the flexible plastic sheet, even if a strong wind blows during a typhoon, the panel itself flutters in the wind, so that an excessive wind pressure load is not applied to the support columns.

Furthermore, by cleaning the photocatalyst panel periodically (for example, once a day) by providing a cleaning means, the photocatalyst is activated and the decontamination function is restored. In this case,
If a washing water drain is provided for each leaf of the photocatalyst panel together with a sprinkling nozzle, washing wastewater containing oxidation products of pollutants (for example, nitric acid) can be collected and discharged to a sewer or the like. Prevents serious environmental pollution. If an alkaline cleaning liquid is used as the cleaning water in advance, the acidic cleaning waste liquid is neutralized, and therefore even if the cleaning waste water is drained, it is safe without affecting the surrounding environment.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of a specific embodiment corresponding to the various modes of the present invention described above will be described below with reference to the drawings. [Embodiment 1] In Fig. 1, a support arm (steel pipe pole) 1 standing outdoors on the ground is provided with a support arm 2 which is vertically arranged in multiple stages and laterally bulged out in a branch shape. The support arm 2 has a fixed shape. A large number of photocatalyst panels 3 manufactured to have dimensions (for example, length, width 50 cm) are suspended and supported in the same manner as leaves of trees. Further, the top of the column 1 is provided with a washing water sprinkling nozzle 4 for sprinkling the washing water toward the photocatalyst panel 3 arranged below, and the sprinkling nozzle 4 is provided with a water supply pipe 5 arranged in the column 1 through a water supply pipe 5. It is connected to the water pipe 6 on the inner side.

As shown in FIG. 2, the photocatalyst panel 3 is made of a flexible plastic sheet having a thickness of about 1 mm, such as vinyl chloride, as the substrate 3a, and the front and back surfaces thereof have a thickness of 1 mm. The following ultra-thin photocatalyst sheet 3b is applied. This photocatalyst sheet 3b has a thickness of 0.5 to 0.5, together with fluorocarbon resin added as a binder by adding activated carbon to a photocatalyst powder containing titanium dioxide as a main component.
It is produced by forming an extremely thin sheet of about 1 mm.

If the tree-like harmful gas removing device having the above-mentioned structure is installed in an area where air pollution occurs, for example, along a main road in an urban area, the photocatalyst is activated by the irradiation of sunlight during the daytime and the atmosphere is removed. NO _X contained in the atmosphere by catalytic reaction, contaminants such as SO _X is adsorbed to the photocatalyst sheet 3b is oxidized. As a result, the surrounding air is purified and the air pollution concentration is reduced.

Further, when the cleaning water supplied through the water supply pipe 5 is sprayed toward the photocatalyst panel 4 from the water spray nozzle 4 once a day except in rainy weather, the contaminants adsorbed on the photocatalyst sheet The oxidation products (nitric acid, etc.) are washed away, and the decontamination function of the photocatalyst is restored. In this case, if water with an alkaline neutralizing agent added is used as the wash water, the wash effluent is neutralized and its pH becomes neutral. There is no risk of contamination.

[Embodiment 2] Another embodiment of the present invention is shown in FIGS. 4 (a) and 4 (b). In the figure, a large number of photocatalyst panels 7 arranged in a spiral form from top to bottom are attached to the circumference of a pillar 1 standing on the ground. here,
As shown in FIG. 3, the photocatalyst panel 7 comprises a hard substrate 7a made of plastic or the like, and a photocatalyst sheet 7b similar to that described in Example 1 adhered to the front and back surfaces thereof.
Further, for each photocatalyst panel 7, a water supply header 8 with a water spray nozzle 8a for spraying washing water toward the surface of the photocatalyst sheet 7b is provided above the substrate 7a, and a washing drain 9 is provided at the bottom. The water supply header 8 is connected to the underground water supply pipe 6 through a water supply pipe 10 provided in the support column 1, and the cleaning drainage receiver 9 communicates with an underground drainage groove 12 through a drainage pipe 11.

The decontamination function of the air pollutants by such a constitution is the same as that described in the first embodiment. Further, at the time of cleaning, cleaning water is sprinkled on the surface of the photocatalyst sheet 7b through the water spray nozzle 8a for each photocatalyst panel 7, and the cleaning drainage is collected in the drainage receiver 9 and then through the drainage pipe 11
It is discharged to 2. As a result, unlike the first embodiment, the cleaning drainage containing the acidic product of the pollutant does not flow down to the surroundings, and there is no risk of secondary environmental pollution.

Next, FIG. 5 shows an example of use in which the harmful gas removing device having the configuration of the above-described first and second embodiments is installed along a main road passing through an urban area. In the figure, 13 is an elevated road for exclusive use of automobiles, 14 is a general road on the ground, and 15 is a buffer zone such as a green belt defined between the sidewalk along the road 14 and the buffer zone 15 of the present invention. The tree-type harmful gas removing devices 16 are arranged one by one at appropriate intervals.

By applying such a harmful gas removing device, the atmosphere polluted by exhaust gas from automobiles running on the elevated road 13 and the general road 14 is purified, and the environment in the city area around the road is improved. become. Moreover, the tree-type harmful gas removing device of the present invention described in the first and second embodiments is almost free from the locational restrictions due to the surrounding buildings, etc., only by setting up a support on the ground and securing a small installation space. It can be installed using existing public land in urban areas.

[0021]

As described above, according to the structure of the present invention, a harmful gas removing device having a large area of photocatalyst per unit and a large decontamination capacity can be obtained by only securing a small installation space on the ground. Can be provided, and by installing it along the main road in urban areas, great results can be expected in improving the environment around the road.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an entire harmful gas removing apparatus corresponding to a first embodiment of the present invention.

FIG. 2 is an external view of a photocatalyst panel used in the harmful gas removing device of FIG.

FIG. 3 is an external view of a photocatalyst panel used in Example 2 of the present invention.

4A and 4B are configuration diagrams of an entire harmful gas removing apparatus corresponding to a second embodiment of the present invention, in which FIG. 4A is a side view and FIG. 4B is a plan view.

FIG. 5 is a diagram showing a usage example in which the harmful gas removing device of the present invention is installed along a main road in an urban area.

[Explanation of symbols]

 1 Support 2 Support Arm 3 Photocatalyst Panel 3a Flexible Substrate 3b Photocatalyst Sheet 4 Water Sprinkling Nozzle 5 Water Supply Tube 7 Photocatalyst Panel 7a Substrate 7b Photocatalyst Sheet 8 Water Supply Header 8a Water Sprinkling Nozzle 9 Wash Water Drain 10 Water Supply Pipe 11 Drain 12 Drain

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location B01J 35/02 B01D 53/36 D 311 102E // B08B 3/02 (72) Inventor Satoshi Nishikata Kanagawa 1-1 Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Japan Fuji Electric Co., Ltd. (72) Inventor Isao Amano 1-1, Tanabe-Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Fuji Electric Co., Ltd.

Claims (8)

[Claims] 1. A contact reaction between a photocatalyst that is activated by the irradiation of sunlight and the atmosphere is utilized to oxidize pollutants such as NO _x and SO _x contained in the ambient air and adsorb to the photocatalyst. It is a harmful gas removing device that captures, and is characterized by installing a number of photocatalyst panels, which are formed by forming a photocatalyst containing titanium dioxide as a main component into a sheet and adhering to the substrate, dispersed around the columns. Gas removal device. 2. The harmful gas removing apparatus according to claim 1, wherein a plurality of support arms branching into upper and lower stages are provided on the support, and the photocatalyst panel is suspended and supported on the supporting arms. . 3. The harmful gas removing device according to claim 1 or 2, wherein a photocatalyst sheet is attached to both front and back surfaces of the substrate of the photocatalytic panel. 4. The harmful gas removing device according to claim 3, wherein the substrate is a flexible plastic sheet. 5. The cleaning apparatus according to claim 1 or 2, wherein the photocatalyst panel is sprinkled with cleaning water supplied from a water supply source to elute and eliminate oxidation products of pollutants adsorbed and captured by the photocatalyst. An apparatus for removing harmful gas, characterized by comprising means. 6. The harmful gas removing apparatus according to claim 5, wherein, as cleaning means, a spray nozzle for spraying cleaning water toward the photocatalyst sheet group is provided at the top of the column. 7. The harmful gas removing apparatus according to claim 5, wherein, as cleaning means, a sprinkling nozzle and a cleaning drainage receiver are provided above and below the substrate for each photocatalyst panel. Removal device. 8. A harmful gas removing device having the structure according to claim 1 installed side by side along a main road in an urban area where traffic of automobiles is high.