JP2000061246A - Air cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air cleaning device capable of reducing the air cleaning load in a clean room by previously removing particles and chemical pollutants in the air and supplying the air high in cleanness to the clean room. SOLUTION: In an outer conditioning machine (air cleaning device) 1, a fan 2 sucking and blowing outdoor air, a dust removing mechanism 3 removing the dust in the air sucked through the fan 2, a temp. and relative humidity controlling mechanism 4 controlling the temp. and relative humidity of the air passed through the dust removing mechanism 3 and a casing 5 collectively housing these mechanisms are provided, and a chemical pollutants removing means 6 removing the chemical pollutants such as ionic component and metal component incorporated in the outdoor air is provided in the casing 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purifying device, and more particularly to an air purifying device which is preferably used as an outside air conditioner (outside air conditioner) for supplying outside air to a clean room of a semiconductor manufacturing factory.

[0002]

2. Description of the Related Art For example, various semiconductor manufacturing equipment is installed in a clean room of a semiconductor manufacturing factory, and an auxiliary equipment room in which auxiliary equipment of each semiconductor manufacturing equipment is installed is formed on the lower floor of the clean room. There is. The clean room and the auxiliary room are partitioned by a free access floor formed by laying a large number of grating panels, for example. Further, outside air whose temperature and humidity have been adjusted is supplied to the inside of the clean room through an external air conditioner, and this air is circulated and used.

However, an extremely high degree of cleanliness is required in the clean room, so fine particles in the outside air are removed through various air cleaning devices such as ULPA filters arranged on the ceiling of the clean room to obtain clean air. I am trying. In addition to particles, the outside air contains chemical contaminants composed of various ion components such as sulfate ions and ammonium ions and metal components such as various metal ions.
A chemical filter is arranged in parallel with the PA filter, and chemical contaminants are removed by the chemical filter (for example, JP-A-6-232017). And
The clean air in the clean room, for example, passes through the clean room in a downward flow, goes to the auxiliary room on the first floor via the free access floor, and returns to the original air cleaning device such as a filter via the return duct to clean the air. The dust is constantly removed through the device to clean the air so that clean air circulates. A part of the clean air in the clean room is always exhausted to the outside, and the exhaust air is replenished from the outside via an external regulator. The conventional external air conditioner is used for adjusting the temperature and humidity and supplying the outside air from which coarse particles are removed into the clean room.

[0004]

However, since the blower is built in the case of the conventional air conditioner, the air conditioner itself becomes a source of particles, and the particles are supplied into the clean room together with the outside air. There is a problem that the load of the air purifying device (filter) in the clean room becomes heavy. Further, chemical contaminants in the outside air are removed by a chemical filter in the clean room. However, if fine processing of 0.18 to 0.20 μm will become the mainstream in the future, chemical contamination will be caused only by the chemical filter in the clean room. There is a problem that it is not enough to remove the substance, and the burden on the chemical filter becomes larger.
Incidentally, Japanese Patent Laid-Open No. 61-276642 proposes an air cleaning device equipped with an air filter and a mechanism for removing sea salt particles. The mechanism for removing this sea salt particles is provided upstream of the air filter. It is arranged and only has the function of preventing contamination of the air filter by sea salt particles.

The present invention has been made to solve the above problems, and removes particles and chemical pollutants in the outside air in advance, supplies highly clean air to a clean room, and cleans the air in the clean room. It is an object of the present invention to provide an air cleaning device that can reduce the above.

[0006]

An air purifying apparatus according to claim 1 of the present invention comprises a blower for sucking and blowing outside air,
A dust removing mechanism that removes dust in the outside air sucked through the blower, a temperature and humidity adjusting mechanism that adjusts the temperature and humidity of the air that has passed through the dust removing mechanism, and a casing that collectively stores these, A chemical pollutant removing means for removing the chemical pollutant contained in the outside air is provided in the casing.

The air purifying apparatus according to a second aspect of the present invention is the air purifying apparatus according to the first aspect, wherein the chemical pollutant removing means stores a water tank for storing water and water in the water tank. And a spray means for spraying toward the outside air.

An air purifying apparatus according to a third aspect of the present invention is characterized in that, in the second aspect of the invention, the water is primary pure water.

An air purifying apparatus according to a fourth aspect of the present invention is characterized in that, in the invention according to the second or third aspect, the water tank is provided with conductivity measuring means. .

An air purifying apparatus according to a fifth aspect of the present invention is the air purifying apparatus according to any one of the first to fourth aspects, further comprising temperature adjusting means for adjusting the temperature of the spray water. It is characterized by that.

An air purifying apparatus according to a sixth aspect of the present invention is the air purifying apparatus according to any one of the first to fifth aspects, wherein the spray water amount (W) from the spray means and the air flow rate. The weight ratio with (A) is set to W / A ≧ 0.5.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the embodiments shown in FIGS. The air cleaning device (for example, an external air conditioner) 1 of the present embodiment is, for example, as shown in FIG.
A fan 2 that sucks and blows outside air, a dust removing mechanism 3 that removes particles in the outside air sucked through the fan 2, and a temperature and humidity adjusting mechanism that adjusts the temperature and humidity of the air that has passed through the dust removing mechanism 3. 4 and a casing 5 accommodating them collectively. Further, a chemical pollutant removing means 6 is provided in the casing 5, and by the chemical pollutant removing means 6, ion components such as sulfate ion, phosphate ion, and chlorine ion contained in the outside air, zinc, Chemical contaminants such as metal components such as copper, nickel and iron are removed. The outlet of the casing 5 is connected to the clean room 8 via the duct 7, and the external air conditioner 1
The clean air obtained in (1) is supplied to the clean room 8 through the duct 7.

The dust removing mechanism 3 removes particles having a relatively large particle diameter in the outside air from the screen filter 31.
And a pre-filter 32 for removing particles that have passed through the screen filter 31, and the pre-filter 3
Medium performance filter 3 that removes particles that have passed 2
3 and 3. Each filter is provided with a clogging detector 31A, 32A, 33A, respectively.
When the clogging is detected by A, 32A and 33A, an alarm is issued.

The temperature / humidity adjusting mechanism 4 is arranged between the dust removing mechanism 3 and the fan 2 and is provided downstream of the fan 2 with a first preheating coil 41 for preheating the air passing through the dust removing mechanism 3. The first spray mechanism 42 is provided with a cooling coil 43 and a second preheating coil 44 that are sequentially arranged on the downstream side of the first spray mechanism 42. And fan 2
The chemical contaminant removing means 6 is interposed between the first spray mechanism 42 and the first spray mechanism 42.

First preheating coil 41, first spray mechanism 4
The second and second preheating coils 44 are respectively connected to a steam source (not shown) so as to preheat or humidify the air passing through the dust removing mechanism 3 by the steam from the steam source. On the other hand, the cooling coil 43 is connected to a coolant supply source (not shown) so that the dew point of the air passing through the first spray mechanism 42 is adjusted by a coolant such as cooling water from the coolant supply source. Then, the cooling coil 43 and the second preheating coil 44 are controlled based on the temperature and humidity in the clean room 8 to set the inside of the clean room 8 to a desired temperature and humidity.

The chemical pollutant removing means 6 is
The primary pure water W in the water tank 61 is directed toward the water tank 61 that stores the primary pure water W and the dust-removed air that passes over the water tank 61.
And a second spray mechanism 62 for spraying. The spray mechanism 62 is connected to the end of the circulation pipe 63 extending from the bottom of the water tank 61 and arranged above the water tank 61. A water supply pump 63A is attached to the circulation pipe 63, and the primary pure water W in the water tank 63 is supplied to the second spray mechanism 62 via the water supply pump 63A and the second spray mechanism 62.
The primary pure water W is sprayed from a plurality of nozzles of the spray mechanism 62. Spray water volume (W) and air volume (A)
The ratio is set according to the content of chemical pollutants in the air, and when the weight ratio (W / A) satisfies W / A ≧ 0.5, the expected effect can be obtained. A heat exchanger 64 is connected to the circulation pipe 63. The heat exchanger 64 keeps the primary pure water W at a constant temperature at all times and maintains the solubility of chemical pollutants at a constant temperature, thereby chemically spraying water. The trapping efficiency of pollutants is kept constant. That is, the circulation pipe 63 is provided with a temperature detector 63B arranged upstream of the heat exchanger 64, and the heat exchanger 64 is provided with an automatic valve 64A for adjusting the amount of steam as a heat source. The automatic valve 64A is proportionally controlled based on the detection value of the detector 63B to keep the temperature of the primary pure water W constant as described above. Further, a conductivity meter 65 and a liquid level meter 66 are provided in the water tank 61, respectively.
5 controls the conductivity of the primary pure water W in the water tank 61,
The liquid level in the water tank 61 is controlled by the liquid level gauge 66.
The water tank 61 has a water supply pipe 67 having an automatic valve 67A.
A conductivity meter 65 and a liquid level meter 66 are electrically connected to the automatic valve 67A, and the automatic valve 67A is opened / closed based on the respective detected values to determine the conductivity of the primary pure water W in the water tank 61. Is maintained below a reference value to maintain the electrical conductivity for efficiently capturing chemical pollutants, and the water level of the primary pure water W does not fall below the reference level.

Further, an eliminator 9 is arranged between the chemical pollutant removing means 6 and the first spray mechanism 42 of the temperature / humidity adjusting mechanism 4, and the eliminator 9 passes over the chemical pollutant removing means 6. The water in the outside air is removed.

A plenum chamber 82 is formed above the ceiling of the clean room 8, and a free access floor 83 made of a grating panel is formed on the floor surface of the clean room 8. A duct chamber 84 is formed below the free access floor 83,
The duct chamber 84 and the plenum chamber 82 are connected via a return duct 85. Therefore,
The clean air supplied from the external air conditioner 1 into the plenum chamber 82 reaches the clean room 8 via the ULPA filter 86, flows downward in the clean room 8, passes through the free access floor 83, and passes through the duct chamber 84 and the return duct. It circulates in the clean room 8 via 85. Furthermore, UL is installed on the ceiling of the clean room 8.
A PA filter 86 is laid, and the ULPA filter 85 ensures that the cleanliness of the circulating air in the clean room 8 is substantially constant.

Next, the operation will be described. When the fan 2 of the external conditioner 1 is driven, the outside air is sucked from the suction port of the casing 5 and the outside air is blown inside the casing 5. Figure 2 shows the chemical pollutants contained in the outside air at this time.
It is as shown in the white bar graph. Next, when the outside air passes through the dust removing mechanism 3, the dust removing mechanism 3 removes particles in the air and cleans the air. When the outside air is continuously sucked, one of the filters 31, 32,
When clogging occurs at 33, the detectors 31A, 32
A and 33A are activated to generate an alarm and notify the clogging of the dust removing mechanism 3. If there is no clogging, the air that has passed through the dust removing mechanism 3 is preheated by the first preheating coil 41 of the temperature and humidity adjusting mechanism 4, and the air after preheating is the chemical pollutant removing means 6
Flowing over. The air temperature at this time is detected by a temperature detector 41B arranged above the water tank 61, and the automatic valve 41A operates based on the detected value to activate the first preheating coil 41.
The amount of heat supplied to the air is adjusted to set the air at a predetermined temperature.

In the chemical pollutant removing means 6, the circulation pipe 6
The water supply pump 63A of No. 3 is driven, and the primary pure water W having a constant temperature is sprayed from the second spray mechanism 62 toward the air flowing above the water tank 61 at a predetermined weight ratio (for example, W / A = 2). , Chemical contaminants such as ionic components and metal components in the air are captured with spray water. At this time, the temperature of the primary pure water W is detected by the temperature detector 63B immediately before the heat exchanger 64, and the amount of water vapor to the heat exchanger 64 is adjusted by the automatic valve 64A which operates based on the detected value. Pure water W
Is kept at a constant temperature and the primary pure water W at a constant temperature is
The spray mechanism 62 sprays toward the air, and the chemical water is efficiently captured by the spray water. When the sprayed water that has captured the chemical contaminants returns to the water tank 61, the ionic component increases in the primary pure water W in the water tank 61, and the conductivity thereof increases. This conductivity is detected by the conductivity meter 65, and when the conductivity exceeds the reference value, the automatic valve 67A opens and the water supply pipe 6
The primary pure water W is replenished from 7 into the water tank 61 to reduce the conductivity below the reference value to stabilize the capture efficiency of chemical pollutants by the spray water. Moreover, the primary pure water W is reduced by the spraying,
Even when the primary pure water W in the water tank 61 falls below the reference water level, the automatic valve 67A operates to supply the primary pure water W into the water tank 61. After removing chemical contaminants such as ionic components and metal components, the eliminator 9 separates and removes water in the clean air. When the chemical pollutants in the air flowing out from the external air conditioner 1 were measured, the results were as shown by the shaded bar graph in FIG. As is clear from the figure, it can be seen that various ion components are significantly reduced.

Subsequently, steam is sprayed from the first spray mechanism 42 of the temperature / humidity adjusting mechanism 4 toward the clean air, and the clean air is once saturated with the steam, and then the cooling coil 43 is used.
To cool the clean air to a specified temperature and adjust the clean air to a specified dew point. Then, the clean air is supplied to the second preheating coil 44.
The temperature and humidity required in the clean room 8 are adjusted by the clean room 8 and the clean air is supplied to the plenum chamber 82 of the clean room 8 through the duct 7. As described above, the first spray mechanism 42 creates a saturated state of water vapor to stabilize the function of the cooling coil 43, reliably detect the dew point, and stabilize the humidity control by the second preheating coil 44. Then, the clean air passes through the ULPA filter 86 in the clean room 8 in a descending flow, passes through the free access floor 83, returns to the plenum chamber 82 via the duct chamber 84 and the return duct 85, and circulates in the clean room 8. To do. Further, the temperature of the clean air in the clean room 8 is detected by the temperature detector 81, and the automatic valve 44A of the second preheating coil 44 is operated based on the detected value, and the clean air blown out from the external air conditioner 1 by adjusting the amount of water vapor. The air is adjusted to a temperature corresponding to the temperature in the clean room 8.

As described above, according to this embodiment,
A fan 2 that sucks and blows the outside air, a dust removing mechanism 3 that removes particles in the outside air sucked through the fan 2, and an adjusting mechanism 4 that adjusts the temperature and humidity of the air that has passed through the dust removing mechanism 3. Since the casing 5 for accommodating them is provided and the chemical contaminant removing means 6 for removing chemical contaminants such as ionic components and metal components is provided in the casing 5, not only particles but also chemical contaminants In particular, it is possible to obtain clean air from which even fine particles (for example, salts such as ammonium chloride and sodium sulfate) that can become ionic components and metal components, which are extremely harmful to the process of semiconductor wafers, are removed, and thus clean the clean room 8. It is possible to supply various air and reduce the load on the ULPA filter 86 and the like in the clean room 8.

Further, according to the present embodiment, the chemical pollutant removing means 6 comprises a water tank 61 for storing the primary pure water W and a second spray mechanism 62 for spraying the water in the water tank 61. Therefore, the primary pure water W causes chemical pollutants,
In particular, water-soluble substances such as ionic components and metal ions can be efficiently captured. Further, since the conductivity meter 65 is provided in the water tank 61, the increase in conductivity due to the ion component dissolved in the water tank 61 can be surely grasped, so that the capturing efficiency of the ion component by the primary pure water W is always stable. Can be converted. Further, since the heat exchanger 64 for adjusting the temperature of the spray water is provided, the solubility of the chemical pollutants can always be maintained at a constant value and the capture efficiency of the chemical pollutants can be stabilized.

It should be noted that the present invention is not limited to the above-described embodiment in any way, and appropriate design changes can be made as necessary. For example, in addition to the above-mentioned components, an air filter or a chemical filter may be added as necessary to more reliably remove particles and chemical contaminants.

[0025]

According to the first to sixth aspects of the present invention, particles and chemical pollutants in the outside air are removed in advance, and highly clean air is supplied to the clean room so that the clean room It is possible to provide an air purifying device that can reduce the air purifying in the air.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a structure of an air conditioner of an embodiment of an air cleaning apparatus of the present invention.

FIG. 2 is a bar graph for explaining the result of removing chemical pollutants contained in the outside air using the air conditioner shown in FIG.

[Explanation of symbols]

1 External conditioner (air purifier) 2 fans (blower) 3 Dust removal mechanism 4 Temperature and humidity control mechanism 5 casing 6 Chemical Pollutant Removal Means 61 aquarium 62 Second spray mechanism (spray means) 64 heat exchanger (temperature control means) 65 Conductivity meter (conductivity measuring means) W primary pure water

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Taiji Fukasawa             2-30-7 Sumiyoshi-cho, Fuchu-shi, Tokyo Tokyo             Within Electron Logistics Co., Ltd. (72) Inventor Takenobu Matsuo             Tokyo Ele 5-3-6 Akasaka, Minato-ku, Tokyo             Inside Kutron Co., Ltd. (72) Inventor Go Wakabayashi             Tokyo Ele 5-3-6 Akasaka, Minato-ku, Tokyo             Inside Kutron Co., Ltd. (72) Inventor Tomoo Gomachi             1-25-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei             Construction Co., Ltd. F-term (reference) 4D020 AA05 AA06 AA10 BA23 BB03                       CB25 CD01 CD02 CD10 DA01                       DA02 DA03 DB01 DB05 DB06                 4D058 JA01 KB11 PA01 PA20 SA04                       TA02 UA01 UA03 UA30

Claims (6)

[Claims] 1. A blower for sucking and blowing outside air, a dust removing mechanism for removing dust in the outside air sucked through the blower, and a temperature / humidity adjustment for adjusting temperature / humidity of air passing through the dust removing mechanism. An air purifying apparatus comprising: a mechanism and a casing that collectively accommodates the mechanism, and a chemical pollutant removing unit that removes a chemical pollutant contained in the outside air is provided in the casing. 2. The chemical pollutant removing means includes a water tank for storing water, and a spraying means for spraying the water in the water tank toward the outside air.
The air cleaning device according to. 3. The air cleaning apparatus according to claim 2, wherein the water is primary pure water. 4. The air cleaning apparatus according to claim 2, wherein the water tank is provided with conductivity measuring means. 5. The air cleaning apparatus according to claim 2, further comprising temperature adjusting means for adjusting the temperature of the spray water. 6. Amount of water sprayed from the spray means (W)
The weight ratio of air flow rate (A) to W / A ≧ 0.5 is set, and the air cleaning apparatus according to claim 2.