JPH0544958A - Air purifying device for clean room - Google Patents

Abstract

PURPOSE:To enable high-efficient removal of a trace amount of a gas component contained in circulating air in a clean room. CONSTITUTION:A high voltage discharge part 17 is located in an circulating air passage 8 of a clean room 1 and a filter 20 for collecting particle, an ozone decomposition catalyst layer 18, and an adsorbent layer 19 are formed on the downstream of the high voltage discharge part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clean room, and more particularly to an air purification device for air circulating in the clean room.

[0002]

2. Description of the Related Art In a clean room, air is circulated through a filter, but a trace amount of gas components that cannot be removed even through the filter are not preferable because they are repeatedly circulated through the clean room. Conventionally, the trace gas components such as odor components, SO ₂ , NH ₃ , NO _{2 and the} like are adsorbed and removed by an adsorbent such as activated carbon.

[0003]

However, since these gas components have extremely low concentrations, there is a problem that the efficiency is extremely poor even if they are adsorbed by activated carbon.

Therefore, an object of the present invention is to solve the above problems and to provide an air purifying device for a clean room, which can efficiently remove a trace gas component contained in the circulating air in the clean room.

[0005]

In order to achieve the above object, the present invention provides a high-voltage discharge part in a circulating air passage of a clean room, and a particulate collection filter, an ozone decomposition catalyst layer, and an adsorbent layer downstream thereof. Is provided.

[0006]

According to the above structure, when the circulating air passes through the high-voltage discharge section, it is turned into plasma, and a chemical reaction of plasma causes a gas phase condensation / atomization reaction of a trace gas component contained in the air. The fine particles can be efficiently removed by the downstream particulate collection filter, and the trace gas component oxidized by the plasma chemical reaction is adsorbed and removed by the ozone decomposition catalyst layer and the adsorbent layer.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an overall view of the present invention. In the figure, 1 is a clean room formed in a building 2 of a factory or the like, an upper part is partitioned by a filter 3, and a lower part is a grating 4 which is a floor surface. Partitioned and formed. An air supply chamber 5 is formed above the filter 3, and a return air chamber 6 is formed below the grating 4. The air in the clean room 1 is circulated in the air circulation passage 8 including the air conditioner 7. That is, air is supplied as clean air from the air supply chamber 5 through the filter 3, descends in the clean room 1, flows through the grating 4 to the return air chamber 6,
It flows from the return air chamber 6 to the air conditioner 7 through the intake duct 9, is air-conditioned by the heat exchanger 10 in the air conditioner 7, flows from the blower fan 11 into the air supply chamber 5 through the blowout duct 12, and circulates in the clean room 1. It is supposed to be done. The outside air introduction duct 13 is connected to the air conditioner 7,
Further, a bypass bus 14 is connected between the intake duct 9 and the outlet duct 12.

The air circulation passage 8 of this clean room 1
In addition, for example, as shown in FIG. 1, an air purifying device 15 is provided in the air supply chamber 5.

As shown in FIG. 2, the air purifying device 15 includes a high voltage discharge unit 1 in a casing 16 through which circulating air passes.
7, an ozone decomposition catalyst layer 18 provided downstream thereof, an adsorbent layer 19 such as activated carbon or zeolite, and a high-performance particulate collection filter 20 are provided. The adsorbent layer 19 and the particulate collection filter 20 may be replaced with each other.

The high-voltage discharge section 17 comprises a linear discharge electrode 21 and a plate-shaped ground electrode 22, and a DC or AC high voltage is applied between the electrodes 21 and 22. This power supply is
As shown in (a) steep pulse voltage, (b) square wave pulse voltage, (c) steep pulse voltage superimposed with DC voltage, (d) positive or negative square wave pulse voltage Good.

Next, the operation of the embodiment will be described.

Odor components, SO ₂ , NH ₃ , NO which cannot be removed by the filter 3 in the air of the clean room 1.
_It contains trace gas components such as ₂ . The air in the clean room 1 flows into the return air chamber 6 through the grating 4, flows from the return air chamber 6 into the air conditioner 7 through the intake duct 9, is conditioned by the heat exchanger 10 in the air conditioner 7, and is blown by the blower fan 11. When passing through the air purifying device 15 in the air supply chamber 5 via the blowout duct 12, the trace gas component in the air is removed. That is, between the electrodes 21 and 22 of the high voltage discharge part 17, the rising 10
A pulse voltage of μS or less, a square wave pulse voltage, or the like is applied, streamer discharge is generated, and a wide space between the electrodes 21 and 22 can be ionized. By this discharge,
O ₂ and N ₂ molecules are ionized and excited to generate ions and radicals, which cause a plasma chemical reaction. On the other hand, most of trace gas components in the air are atomized by this discharge plasma chemical reaction (for example, SO ₂ , NH ₃ , NO).
₂ and other atomization).

When the circulating air passes through the high-voltage discharge section 17, it is turned into plasma and the trace gas components contained in the air are also ionized.

These fine particles can be efficiently removed by the fine particle collecting filter 20 located downstream. Further, in the plasma chemical reaction in the air, an oxidation reaction due to O and OH radicals also takes place, and a trace amount of gas components such as activated carbon and zeolite which are easily adsorbed in the adsorption layer 19 can be removed by being oxidized. Further, ozone and nitrogen dioxide generated from the air are removed by the ozone decomposition catalyst layer 18 and also by the adsorption layer 19. The discharge power of the discharge unit 17 and the range of 10 ⁻³ to 10 [J] per 1 g of air are set.

The air that has passed through the air purifier 15 is circulated from the air supply chamber 5 to the clean room 1 through the filter 3. When the voltages (b) and (c) in the voltage of FIG. 3 are applied to the discharge part 17, the dust particles are not charged.
It also has a dust collecting effect.

Next, another embodiment of the present invention will be described with reference to FIGS.

4 (a) and 4 (b) show a high voltage discharge part 17
Is formed of a honeycomb or cylindrical ground electrode 25 and a needle-shaped discharge electrode 26 facing the inside of each honeycomb or cylindrical ground electrode 25. This needle-shaped discharge electrode 26
Is applied with a steep pulse voltage in FIG. 3 and a square wave pulse voltage in FIG.

In FIG. 5, a needle-shaped discharge electrode 26 is made to face each honeycomb or cylindrical ground electrode 25 from the upstream side, and a ground electrode 27 is provided on the front surface of the ozone decomposition catalyst layer 18. In this case, each honeycomb or cylindrical ground electrode 25
A discharge occurs inside the discharge electrode 26 and the ground electrode 27.

FIG. 6 shows the ground electrode 2 in which the high-voltage discharge part 17 is provided in front of the needle-shaped discharge electrode 28 and the ozone decomposition catalyst layer 18.
An example formed by 9 and 9 is shown.

FIG. 7 shows an example of the ozonizer type high-voltage discharge part 17, in which the discharge electrode 30 is surrounded by an insulating cylinder 31 made of glass or ceramic, and the ground electrode 32 is provided on the outer periphery of the insulating cylinder 31. .. Any of the voltages (a) to (d) shown in FIG. 3 may be applied between the electrodes 30 and 32. In this ozonizer type high-voltage discharge part 17, a silent discharge is uniformly generated, and by this discharge, O ₂ and N ₂ molecules are ionized and excited to generate ions and radicals, which cause a plasma chemical reaction. The trace gas component can be atomized and removed.

FIG. 8 also shows a high-pressure discharge part 1 of the ozonizer type.
7, an insulating plate 34 is opposed to the linear discharge electrode 33, and a ground electrode 35 is provided on the back surface of the insulating plate 34. Any of the voltages (a) to (d) shown in FIG. 3 may be applied between the electrodes 33 and 35.

In FIG. 9, the inlet 16a of the casing 16 is narrowed, and the high-pressure discharge part 17 is provided at the narrowed inlet 16a.
In the casing 16 on the downstream side, an ozone decomposition catalyst layer 18, an adsorbent layer 19 and a particulate collection filter 20 are provided. In this example, by increasing the flow velocity of the air in the high-pressure discharge unit 17, the discharge unit 17 can be downsized and efficient ionization can be performed.

In the above-mentioned embodiments, an example in which a metal electrode is used as an electrode has been described, but in addition to the discharge electrode ground electrode, a method of suppressing the generation of fine particles by discharge sputtering by glass thin film coating or ceramic coating is also possible. is there.

[0025]

In summary, according to the present invention, a wide range of the gas passage region is ionized by a high voltage discharge to cause a gas phase / condensation of a trace gas component by a plasma chemical reaction, which is used as a particulate collection filter. Can be removed with.

[Brief description of drawings]

FIG. 1 is an overall view showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of FIG.

FIG. 3 is a diagram showing an example of a voltage waveform applied to a high-voltage discharge unit in the present invention.

FIG. 4 is a diagram showing another embodiment of FIG.

FIG. 5 is a diagram showing another embodiment of FIG.

FIG. 6 is a diagram showing another embodiment of FIG.

FIG. 7 is a diagram showing another embodiment of FIG.

FIG. 8 is a diagram showing another embodiment of FIG.

FIG. 9 is a diagram showing another embodiment of FIG.

[Explanation of symbols]

 1 Clean Room 5 Air Supply Chamber 8 Air Circulation Passage 15 Air Purifier 17 High-Voltage Discharge Unit 18 Ozone Decomposition Catalyst Layer 19 Adsorbent Layer 20 Particle Collection Filter

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akira Shibuya 6-17-16 Higashi Narashino, Narashino City, Chiba Prefecture Asahi Kogyo Co., Ltd. Technical Research Institute (72) Hiroaki Abe 6-17-16 Higashi Narashino, Narashino City, Chiba Prefecture Issue Asahi Industry Co., Ltd. Technical Research Institute (72) Inventor Hitoshi Kono 6-17-16 Higashi Narashino, Narashino City, Chiba Prefecture Asahi Industrial Co., Ltd. Technical Research Institute (72) Inventor Shigeo Honda 6-17 Higashi Narashino, Narashino City, Chiba Prefecture No. 16 Asahi Kogyo Co., Ltd. Technical Research Center

Claims (1)

[Claims] 1. An air purifying apparatus for a clean room, characterized in that a high-voltage discharge section is provided in a circulating air passage of the clean room, and a particulate collection filter, an ozone decomposition catalyst layer, and an adsorbent layer are provided downstream thereof.