JP3747708B2 - Toxic gas removal device - Google Patents

Description

【００２５】
表１に示したように、本実施形態のガス除去装置においては、ガス除去効率が８０〜９０％であり、ケミカルフィルタにおけるガス除去効率の７０〜８０％に比して上昇させることができる。また、気体を過飽和状態にするのに必要な蒸気量は、試作品に比べて４０％減少させることができる。このため、蒸気を生成するのに費やしていたコストを低減することができ、またエネルギーを節約することができる。すなわち、表１に示したように試作品と本実施形態のガス除去装置を同一のクリーンルームに設置した場合において、年間に必要な蒸気量は従来２００００ｋｇなのに対して、本実施形態においては、１１４００ｋｇであり、年間を通じて、８６００ｋｇもの蒸気量の低減を行うことが可能である。
【００２６】
このように、本実施形態のガス除去装置１においては、有害ガス含有気体は水接触エレメントにて加湿された後に、蒸気供給手段にて必要量の蒸気を供給することにより過飽和状態を形成させるため、蒸気供給量が少なくてすむ。このため、有害ガスを除去する際にコストやエネルギーの低減を図ることができるとともに、有害ガスの除去効率も高めることができる。
【００２７】
本実施形態においては、２つの水接触エレメントの間に蒸気噴霧器を配置した場合について説明したが、水接触エレメントの数はこれに限られない。水接触エレメントが単数の場合には、当該エレメントの後段に蒸気噴霧器を配置することにより実施形態と同様の作用効果を得ることができる。また、本体を空調機に一体的に取付ける構成としたが、ガス除去装置本体部内に凝縮手段である冷却コイルを設けて、空調機と独立に配置してもよい。また、実施形態においては、前記気体の流入経路にガス除去装置を組み込む事により、前記気体中の有害ガスを除去してクリーンルーム内に流入させる場合について説明したが、クリーンルーム中を循環した空気をガス除去装置に導入することにより、クリーンルーム内にて発生した有害ガスを取り除くことができる。また、蒸気供給手段を複数の水接触エレメントの後段に配置すれば、供給する蒸気量をさらに低減させることができる。
【００２８】
また、本実施形態のガス除去装置はクリーンルームに好適に使用することができるが、適用対象はクリーンルームに限らず、前記気体中からの有害ガスを除去する場合、また室内にて発生した有害ガスを除去する場合にも好適に使用することができる。
【００２９】
【発明の効果】
以上説明したように、本発明に係る有害ガス除去装置によれば、有害ガス含有気体は水接触エレメントにて加湿された後に、蒸気供給手段にて必要量の蒸気を供給することにより過飽和状態を形成させるため、蒸気供給量が少なくてすむ。このため、有害ガスを除去する際にコストやエネルギーの低減を図ることができるとともに、有害ガスの除去効率も高めることができる。
【００３０】
また、蒸気を供給した水接触エレメントに通過させた後に蒸気供給手段を通過させることにより、供給蒸気量を低減することができるとともに、水接触エレメントに再度通過させることにより、有害ガスを含んだ凝縮水を除去し、さらにエレメントの水との気液接触によりガス除去効率を高め、また気体中に供給される水分を均等化させることができる。
また、有害ガス含有気体に複数の水接触エレメントを通過させることにより、水接触エレメントが単数の場合に比して水分の供給量を増大させることができる。このため、蒸気供給手段にて供給する蒸気量を相対的に減少させることができる。
【図面の簡単な説明】
【図１】本発明に係る有害ガス除去装置の実施形態に係る断面図である。
【図２】本発明の有害ガス除去装置を用いるクリーンルームの概略断面図である。
【図３】本発明に係る有害ガス除去装置における水接触エレメントの正面図である。
【符号の説明】
１ 有害ガス除去装置
２ 空調機
３ 有害ガス除去装置本体
４ 水接触エレメント
５ 蒸気噴霧器
６ 水接触エレメント
７ プレフィルタ
８ 中フィルタ
９ 冷却コイル
１０ ファン
１１ ＨＥＰＡフィルタ
２０ 本体フレーム
２１ 加湿モジュール
２２ 給水ヘッダ
２３ 給水ユニット
３０ クリーンルーム
３２ 天井
３４ ファンフィルタユニット
３６ 二重床
３８ 空気の流れ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a harmful gas removing device that removes harmful gas in a gas, and more particularly to a harmful gas removing device that removes harmful gas from gas flowing into a clean room or circulating gas.
[0002]
[Prior art]
Conventionally, in a clean room such as a semiconductor manufacturing factory, it is necessary to maintain the cleanliness of the room, and particles such as dust in the clean room are removed by a filter.
However, harmful gas may be contained in the outside air flowing into the clean room, or harmful gas may be generated in the clean room. In a clean room, it is necessary to remove harmful gases from the aspect of product quality control.
[0003]
Conventionally, as a device for removing harmful gas in a clean room, there is a chemical filter that removes harmful gas from the gas by adsorption or decomposition. An example of such a chemical filter is shown in Japanese Patent Laid-Open No. 10-174838. However, the conventional chemical filter has a harmful gas removal efficiency of about 70%, and the filter adsorbing the harmful gas becomes an industrial waste, which has a problem in the disposal process.
[0004]
In view of this, a toxic gas removal device has been proposed in which a toxic gas component of a toxic gas-containing gas is dissolved in moisture to remove the toxic gas from the gas.
In the harmful gas removal apparatus, the gas is humidified by passing the gas containing harmful gas through the water contact element, and further, the toxic gas is removed by gas-liquid contact with water. Furthermore, moisture can be condensed by cooling the humidified gas, and harmful gas components can be taken into the condensed water to remove harmful gas from the gas and flow into the clean room.
[0005]
In such a harmful gas removal device, the removal efficiency of the harmful gas can be increased, and there is no concern about the generation of industrial waste unlike a chemical filter. For this reason, it is desired to perform harmful gas removal with such a harmful gas removing device.
[0006]
[Problems to be solved by the invention]
However, there are the following problems in removing harmful gases with the harmful gas removing device.
The removal effect of harmful gas by gas-liquid contact with the water contact element is not so different between summer and winter, but the removal effect of harmful gas by water condensation in the cooling coil (condenser) is large in summer. Since there is almost no removal effect due to moisture condensation in the winter season, in order to prevent seasonal fluctuations in removal efficiency, it is possible to obtain the same removal effect as in the summer season by condensing the harmful gas-containing gas into a supersaturated state by steam spraying . However, if the water contact element is passed after vapor spraying the harmful gas-containing gas, the amount of steam required to reach the supersaturated state becomes large. If the amount of steam is large, the energy and running cost necessary for generating steam become large, so the energy and running cost for removing harmful gases also become large.
[0007]
The first object of the present invention is to provide a harmful gas removal apparatus that can maintain high removal efficiency.
The second object of the present invention is to increase the efficiency of energy and running cost in removing harmful gases by efficiently supplying steam necessary for removing harmful gases.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the harmful gas removal apparatus according to the present invention is provided with a water contact element for humidifying a gas containing a harmful gas on the upstream side of the gas flow path, and a condensing means for condensing the harmful gas. A plurality of the water contact elements are provided between the water contact element and the condensing means, and a plurality of the water contact elements are provided between the water contact element and the condensing means. it has a structure you characterized in that a said steam supply means between.
[0010]
[Action]
In the above configuration, the harmful gas-containing gas is first humidified by the water contact element. After this state, a supersaturated state is formed in the gas by supplying steam with the steam supply means. Since the gas has already been humidified by the water contact element, it is possible to reduce the amount of steam supplied to bring the gas into a supersaturated state. Thereby, when removing harmful gas, cost and energy can be reduced, and removal efficiency of harmful gas can be increased.
[0011]
With the above configuration, the amount of supplied steam can be reduced by passing the steam supply means after passing through the water contact element, and the condensed water containing harmful gas can be reduced by passing the water contact element again. Further, the gas removal efficiency in the gas can be enhanced by the action of dissolving the harmful gas in the moisture by gas-liquid contact. That is, in the above configuration, the gas cooling action can be exerted by the water contact element at the rear stage of the steam supply means. Thereby, moisture in the gas can be condensed, and harmful gas can be dissolved in the condensed water and removed from the gas. For this reason, even when the function of the condensing means stops, high gas removal efficiency can be maintained throughout the year.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a harmful gas removal apparatus 1 according to the present invention will be described in detail with reference to the drawings and tables.
FIG. 1 is an explanatory view of the structure of a harmful gas removal apparatus 1 according to this embodiment. FIG. 2 is a cross-sectional view of the clean room 30 in which the harmful gas removal device 1 of the present embodiment is arranged.
[0014]
The clean room 30 is connected to the air conditioner 2 that flows in outside air. A fan filter unit 34 is provided on the lower surface of the ceiling 32 to remove dust when air-conditioned air 38 is allowed to flow into the room. The floor surface 36 of the clean room 30 is a double floor, and indoor air 38 can be discharged from the lower surface of the double floor 36. In this way, the air 38 can be circulated in the clean room 30. In the clean room 30 as described above, it is necessary to maintain the cleanliness of the room air from the viewpoint of product management. For this reason, it is necessary to remove harmful gases in the outside air flowing into the clean room 30. In this embodiment, the case where the harmful gas removal apparatus 1 is arrange | positioned in the air conditioner 2 which flows in outside air in the clean room 30, and harmful gas is removed from the outside air which is harmful gas containing gas is demonstrated. The harmful gases mentioned here include SOx, H ₂ S contained in large amounts in volcanic zones, Na in sea salt particles, HF, HCl, NH ₃ generated during chemical evaporation, and factory exhaust. SOx etc. are mentioned.
[0015]
The harmful gas removal apparatus 1 in the present embodiment has the following configuration. The harmful gas removal apparatus 1 in the present embodiment has a configuration in which the gas removal apparatus main body 3 is integrated in the air conditioner 2. The gas removing device main body 3 has a plurality of water contact elements 4 and 6. FIG. 3 is a front view and a side view of the water contact elements 4 and 6 in the present embodiment. In the water contact elements 4 and 6 in the present embodiment, a plurality of humidification modules 21 made of glass fiber are arranged in the main body frame 20 in the vertical direction. A water supply unit 23 is connected to the upper portion of the humidification module 21 via a water supply header 22, and water is always allowed to flow into the humidification module 21 by the water supply unit 23. In this manner, the gas passing through the water contact elements 4 and 6 is humidified by dropping and supplying water to the humidification module from above. That is, the water supplied to the humidification module exchanges heat with the gas passing through the water contact elements 4 and 6, whereby moisture is vaporized and evaporated, and the gas can be humidified. The shape of the water contact element is not limited to this as long as it can humidify the surroundings.
[0016]
In the present embodiment, a steam sprayer 5 as a steam supply means is provided between the water contact elements 4 and 6. In the present embodiment, the vapor sprayer 5 is disposed on the cross section of the gas flow path in the gas removing device main body 3. The steam sprayer 5 has a plurality of pipes arranged at regular intervals on the cross section. And the nozzle hole which injects a vapor | steam in a fixed area | region is provided in the said pipe along the up-down direction. The steam sprayer 5 is connected to a steam supply path (not shown), and steam is supplied into a pipe in the steam sprayer 5 through the steam supply path. And a vapor | steam can be sprayed to a fixed area | region from the nozzle hole provided in the pipe of the said vapor sprayer 5. FIG. In the present embodiment, the nozzle holes are provided at predetermined intervals. Thereby, vapor can be uniformly supplied to the entire space into which gas flows. In the present embodiment, a switching valve is provided in the steam supply path to the steam sprayer 5 to open and close the supply path according to the season (according to the humidity of the gas) and adjust the steam supply amount. It is something to make. In other words, when wet such as in summer, the flow path of the steam supply path of the steam sprayer 5 is closed to remove harmful gas without supplying steam. When drying such as in winter, the steam supply path is opened and steam is supplied by the steam sprayer 5 to humidify the toxic gas-containing gas. By doing in this way, a toxic gas containing gas can be made to be a constant supersaturation state irrespective of a season, and the fluctuation of removal efficiency can be prevented and made constant. In this embodiment, steam is supplied until the gas is supersaturated. Thereby, although mentioned later for details, melt | dissolution of the harmful gas in the water | moisture content can be accelerated | stimulated, and gas removal efficiency can be improved significantly.
[0017]
The structure of the air conditioner 2 incorporating the gas removing device main body 3 will be described. The air conditioner 2 can collect dust in the gas in which a pre-filter 7 is disposed on the front side of the gas removing device main body 3 and an intermediate filter 8 is disposed on the subsequent stage. In the present embodiment, the mesh of the middle filter 8 is made finer than the prefilter 7 in order to increase the dust collection efficiency. Accordingly, relatively large dust can be collected by the pre-filter 7 and relatively small dust can be collected by the middle filter 8.
[0018]
And the cooling coil 9 which is a condensation means is arrange | positioned in the back | latter stage side of the gas removal apparatus main-body part 3. As shown in FIG. The cooling coil 9 cools the gas and condenses moisture in the gas. The cooling coil 9 in this embodiment condenses moisture in the gas by flowing cold water into the pipe and cooling the surrounding gas. The pipe has a coiled shape, and the condensation area is increased by increasing the contact area with the gas. Note that the shape of the cooling coil 9 is preferably a shape that increases the condensation efficiency. For example, the cooling coil 9 may be bent in a zigzag shape to increase the condensation efficiency. Of course, the condensing means is not limited to the cooling coil 9 as long as it condenses moisture in the gas.
[0019]
A fan 10 is provided at the subsequent stage of the cooling coil 9, and the gas from which harmful gases have been removed is sent out to the rear of the apparatus by the fan 10. In addition, a HEPA filter 11 is disposed behind the fan 10, and particulates are collected by the HEPA filter 11 to prevent inflow into the clean room 30.
[0020]
The operation of the harmful gas removal device 1 in the present embodiment configured as described above is as follows.
When a gas containing toxic gas (outside air) flows into the clean room 30 via the air conditioner 2, the gas first passes through the pre-filter 7 and the middle filter 8. The pre-filter 7 and the middle filter 8 remove dust in the gas.
Then, the gas passes through the water contact element 4. At this time, the gas is humidified by passing through the water contact element 4. Moreover, a part of harmful gas component melt | dissolves in the water | moisture content in the water contact element 4, and is removed from the said gas.
[0021]
In the toxic gas removing device 1 of the present embodiment, a steam sprayer 5 that supplies steam to the gas is disposed at the rear stage of the water contact element 4. For this reason, the gas is humidified to near the saturation point by the water contact element 4. Therefore, the amount of steam for bringing the gas into a supersaturated state can be greatly reduced as compared with the case where it is arranged in the previous stage. Therefore, the energy and running cost required to generate steam can be reduced. In the present embodiment, the supply amount of the steam is adjusted by opening and closing the steam supply path to the steam sprayer 5 according to the season. As described above, in winter when the gas is dry, humidification is performed by opening the valve of the steam supply path and supplying steam. In summer, when the humidity in the gas is sufficiently high, the supply of steam is stopped by closing the valve. Accordingly, high toxic gas removal efficiency can be maintained throughout the year, and steam can be used efficiently. In the present embodiment, steam is supplied until the gas becomes supersaturated in winter. Thereby, melt | dissolution of toxic gas can be accelerated | stimulated and condensation efficiency can further be improved. Therefore, the gas removal efficiency can be further increased.
[0022]
In the present embodiment, the water contact element 6 is allowed to pass even after the steam is supplied by the steam sprayer 5. By passing the gas through the water contact element 6, the gas can be further humidified. In this embodiment, the toxic gas-containing gas is in a supersaturated state before passing through the subsequent water contact element 6 as described above. For this reason, the water | moisture content in the gas which was in the supersaturated state at the time of passage of the water contact element 6 condenses by using the fine particles in the gas as a nucleus and becomes condensed water. At this time, the harmful gas is taken into the condensed water, so that the harmful gas can be removed. As described above, in this embodiment, the water contact element 6 in the subsequent stage has not only a gas humidifying action and a gas removing action by gas-liquid contact but also a function as a condensing means by cooling the gas. Yes. For this reason, even when the cooling coil which is the cooling means arranged in the subsequent stage does not function in winter, the cooling efficiency can be kept high. Further, since the gas is entirely humidified, the distribution of the supplied water can be made uniform. By setting it as such a state, the said gas can be uniformly humidified and the melt | dissolution of a harmful gas component can be equalized.
[0023]
In this way, after the gas is supersaturated, the gas is cooled also in the cooling coil 9 which is a cooling means, and moisture in the gas is condensed and liquefied. As described above, since the harmful gas component in the gas is dissolved in the moisture during the moisture condensation, the harmful gas component can be removed together with the moisture from the gas.
Then, the gas is sent to the outlet side by the fan 10, the fine particles are collected by the HEPA filter 11, cleaned, and introduced into the clean room 30.
By removing harmful gas as described above, the removal efficiency of harmful gas in the gas can be kept high throughout the year.
[0024]
The gas removal efficiency of the gas removal apparatus 1 in this embodiment will be described using Table 1. Table 1 is a comparative table showing the respective gas removal efficiency statuses in the harmful gas removal apparatus.
[Table 1]

[0025]
As shown in Table 1, in the gas removal device of the present embodiment, the gas removal efficiency is 80 to 90%, which can be increased compared to 70 to 80% of the gas removal efficiency in the chemical filter. In addition, the amount of vapor required to bring the gas into a supersaturated state can be reduced by 40% compared to the prototype. For this reason, the cost spent to generate steam can be reduced, and energy can be saved. That is, as shown in Table 1, when the prototype and the gas removal apparatus of the present embodiment are installed in the same clean room, the amount of steam required per year is conventionally 20000 kg, whereas in this embodiment, it is 11400 kg. Yes, it is possible to reduce the amount of steam as much as 8600 kg throughout the year.
[0026]
Thus, in the gas removal apparatus 1 of the present embodiment, the harmful gas-containing gas is humidified by the water contact element, and then a supersaturated state is formed by supplying a necessary amount of steam by the steam supply means. , Less steam supply. For this reason, when removing harmful gas, cost and energy can be reduced, and the removal efficiency of harmful gas can be increased.
[0027]
In this embodiment, although the case where the vapor sprayer was arrange | positioned between two water contact elements was demonstrated, the number of water contact elements is not restricted to this. When there is a single water contact element, the same effect as that of the embodiment can be obtained by disposing a steam sprayer downstream of the element. Moreover, although it was set as the structure which attaches a main body to an air conditioner integrally, the cooling coil which is a condensing means may be provided in a gas removal apparatus main-body part, and you may arrange | position independently. Further, in the embodiment, a case has been described in which a harmful gas in the gas is removed and incorporated into a clean room by incorporating a gas removal device in the gas inflow path. By introducing it into the removal device, harmful gases generated in the clean room can be removed. Further, if the steam supply means is arranged at the subsequent stage of the plurality of water contact elements, the amount of steam to be supplied can be further reduced.
[0028]
In addition, the gas removal apparatus of the present embodiment can be suitably used in a clean room, but the application target is not limited to a clean room, and when removing harmful gas from the gas, harmful gas generated indoors It can also be suitably used for removal.
[0029]
【The invention's effect】
As described above, according to the harmful gas removal apparatus of the present invention, the harmful gas-containing gas is humidified by the water contact element, and then the supersaturated state is obtained by supplying a necessary amount of steam by the steam supply means. Because of this, less steam supply is required. For this reason, when removing harmful gas, cost and energy can be reduced, and the removal efficiency of harmful gas can also be improved.
[0030]
In addition, it is possible to reduce the amount of steam supplied by passing the steam through the water contact element that has been supplied with steam, and to reduce condensation by containing the harmful gas by passing it again through the water contact element. It is possible to remove water, further improve gas removal efficiency by gas-liquid contact with the water of the element, and equalize water supplied to the gas.
Further, by passing a plurality of water contact elements through the harmful gas-containing gas, it is possible to increase the amount of water supply as compared with a case where there is a single water contact element. For this reason, the amount of steam supplied by the steam supply means can be relatively reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view according to an embodiment of a harmful gas removal apparatus according to the present invention.
FIG. 2 is a schematic cross-sectional view of a clean room using the harmful gas removal apparatus of the present invention.
FIG. 3 is a front view of a water contact element in a harmful gas removal apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Toxic gas removal apparatus 2 Air conditioner 3 Toxic gas removal apparatus main body 4 Water contact element 5 Steam sprayer 6 Water contact element 7 Prefilter 8 Medium filter 9 Cooling coil 10 Fan 11 HEPA filter 20 Body frame 21 Humidification module 22 Water supply header 23 Water supply Unit 30 Clean room 32 Ceiling 34 Fan filter unit 36 Double floor 38 Air flow

Claims (1)

A water contact element for humidifying a gas containing harmful gas is provided on the upstream side of the gas flow path, and a condensing means for condensing the harmful gas component is provided on the downstream side of the gas flow path, and steam is supplied to humidify the gas. Disposing a steam supply means between the water contact element and the condensing means;
The water contact elements as a plurality, wherein the harmful gas removing apparatus you characterized in that a steam supply means between the plurality of water contact elements.

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