JP2000167340A - Apparatus for removing gaseous chemical pollutant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gaseous chemical pollutant removal apparatus capable of sufficiently removing gaseous chemical pollutants from an object air to be treated, small in size in the whole body and easy to be maintained, and operable at a low running cost. SOLUTION: A blower 7, an air washer 8, and chemical filters 12, 13 are installed in a casing having an air inlet 3 and an air outlet 4 and an object air to be treated is passed through the air washer 8 and the chemical filers 12, 13 in this order by operation of the blower 7. The air washer 8 is provided with an element 14 made of fibers and having water retaining property and air ventilative property and the object air flowing through the element is brought into contact with water sprayed from the upper side of the element to remove gaseous chemical pollutants in the object air. Each chemical filter 12, 13 is constituted by housing a sheet-like filter 20 produced by impregnating activated carbon fibers as base materials with a chemical adsorbent in a filter casing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for removing gaseous chemical pollutants in air, and more particularly to an apparatus for removing gaseous chemical pollutants from factory air or outside air introduced into a clean room such as a semiconductor factory.

[0002]

2. Description of the Related Art Conventionally, an apparatus for removing gaseous chemical contaminants in air is provided with a chemical filter and an air washer.

[0003] Since chemical filters are expensive, they are rarely used alone in a general removing device.
An air washer is provided before the chemical filter, and the air to be treated is first passed through the air washer to remove water-soluble gaseous chemical contaminants to reduce the amount of contaminants.After that, the air to be treated is passed through the chemical filter. By removing the remaining gaseous chemical contaminants, the life of the chemical filter is extended.

The chemical filter used in the conventional apparatus has a structure in which granular pellets coated with a chemical adsorbent are filled in an adsorption tower, and air to be treated is introduced into the adsorption tower. There is a problem that the resistance is large, the work of exchanging pellets is troublesome, and the installation space is large.

The air washer in the conventional apparatus is mainly of a type called a packed tower type, and the air washer of the packed tower type is to bring the air to be treated into contact with pure water dropped in the tower. In order to increase the contact area between pure water and air, a number of corrugated sheets of resin moldings are arranged in a packed tower to increase the contact area between pure water and air. Pure water is allowed to flow down on the surface of.

[0006] The above-mentioned conventional chemical filter and the packed tower type air washer are both large and have a large installation space, a large pressure loss of air, and a large amount of pure water is used in the air washer. There is a problem that the cost increases. Therefore, the conventional apparatus requires, for example, 2 mx vertical to obtain a processing capacity of 100 m ³ / min.
It requires an installation space of about 15 m in width and about 3.5 m in height, and there is a strong demand for miniaturization of the entire apparatus, as well as maintenance and energy savings.

[0007]

An object of the present invention is to remove gaseous chemical contaminants sufficiently, and furthermore, the entire apparatus is small in size, easy to maintain, and capable of reducing running costs. A contaminant removal device is provided.

[0008]

In order to achieve the above object, a gaseous chemical pollutant removing apparatus according to the present invention comprises a blower, an air washer and a chemical filter in a casing having an air inlet and an air outlet. The air to be treated is circulated in the order of the air washer and the chemical filter by driving the air washer, and the air washer is made of a fiber material and includes a plurality of elements having water retention and air permeability in series, and at least the elements in the final air washer Pure water is sprinkled on the element, but water other than pure water is sprinkled on at least the element in the first-stage air washer, and the air to be treated flowing through each element is brought into contact with the water sprayed onto the element from above. As a result, gaseous chemical contaminants in the air to be treated are removed, and the chemical filter chemically cleans the activated carbon fiber as a base material. By impregnating the Chakuzai there as the structure containing a filter material that is formed into a sheet in the filter casing.

A sensible heat exchanger for exchanging heat of air to be processed before and after an air washer is provided in the casing, and at least an air cooler and an air heater for air conditioning are provided at appropriate places in the casing. Is arranged.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a gaseous chemical pollutant removing apparatus according to the present invention. The inside of the casing 1 is vertically divided by a horizontal partition plate 2, and an air flow path from the air inlet 3 to the air outlet 4 via the lower chamber 1A, the opening 2a of the horizontal partition plate, and the upper chamber 1B is formed. In the lower chamber 1A, a pre-filter 5, a heater 6, a blower 7, and an air washer 8 are arranged in this order from the air inlet 3 side, and in the upper chamber 1B, the air outlet 4 is provided from the opening 2a side. Air conditioner cooler 9, air conditioner heater 10, reheater 11, first chemical filter 1
2, the second chemical filter 13 is arranged in this order.

The air to be treated from the air inlet 3 is cleaned of dust by the pre-filter 5, heated by the heater 6, and sent to the air washer 8 via the blower 7. The heater 6 is for preventing freezing of water in the air washer 8 when the outside air having a temperature below the freezing point is introduced from the air inlet 3 in, for example, a cold region. In some cases, it may not be provided when cleaning or cleaning the air in the factory.

The air washer 8 has an element 14 having water retention and ventilation, a watering header 15 for spraying pure water to the element 14, and a water tank 16 for receiving pure water sprayed from the watering header and flowing down the element. And a water supply pipe 17 for sending water in the water tank to the watering header. A water pump 18 is provided in the middle of the water supply pipe.
Is connected to a water supply pipe 19 for supplying pure water from the outside.

For example, as shown in FIG. 2, the element 14 is formed by forming a sheet made of an inorganic fiber material into a corrugated sheet 14a, and laminating a large number of corrugated sheets so that the folds of adjacent corrugated sheets are oblique to each other. While the pure water from the sprinkling header 15 flows downward from above, the air to be processed flows laterally along the corrugations of the corrugated sheet from the side, and the pressure loss of the air is small. is there.

In the above element, the water does not flow down the surface of the element, but rather penetrates into the element and flows down slowly, so that the residence time in the element is long and the water hardly scatters. The spraying amount of pure water from the spraying header 15 is much smaller than that of a conventional filling type air washer (1.
/ 100). Further, pure water is always supplied from the water supply pipe 19 to prevent freezing of the element.

The air to be treated, from which water-soluble gaseous chemical contaminants have been removed by flowing through the air washer 8, enters the upper chamber 1B through the opening 2a of the horizontal partition plate and passes through the air-conditioning cooler 9 and the heater 10. After passing through the reheater 11, it is discharged from the air outlet 4 through the first and second chemical filters 12 and 13.

The air-conditioning cooler 9 and the heater 10 are supplied with a refrigerant, brine or cold / hot water from the outside. The air-conditioning cooler 9 and the heater 10 are provided for adding an air conditioning function to the removing device, and are not provided. In some cases.

The reheater 11 serves to reduce the relative humidity of the air to be treated, which has increased in humidity via the air washer 8, and to send it to the chemical filters 12, 13, and the chemical filter absorbs moisture. This prevents the adsorbing power of gas components from decreasing.

As shown in FIG. 3, the chemical filters 12 and 13 are formed by forming activated carbon fiber as a base material into a sheet shape and impregnating a known chemical adsorbent with the filter material 20 in a casing 21 as shown in FIG. The gaseous chemical contaminants to be adsorbed can be determined according to the type of the chemical adsorbent.
In the chemical filter described above, different types of gaseous chemical contaminants to be adsorbed and impregnated with different chemical adsorbents may be different, and a plurality of filter materials 20 impregnated with different chemical adsorbents may be laminated to form a casing 21. In some cases, only one chemical filter may be provided, or three or more chemical filters may be provided.

The casing 21 of the chemical filter is formed to have the same dimensions as the casing of a medium-performance filter used in general air conditioning equipment, and can be replaced together with the casing as in the case of the medium-performance filter, and maintenance is required. It is easy and may be connected to a medium-performance filter.

FIG. 4 is a table showing the results of an experiment conducted on the removal of a gas comprising a sulfuric acid compound and an ammonia compound from air using the apparatus of the present invention configured as described above. In the removal experiment, the concentration of sulfate ion (SO ₄ ²⁻ ) and the concentration of ammonia ion (NH ₄ ⁺ ) were measured at the air inlet 3, the outlet of the air washer 8, and the air outlet 4, respectively.

From the results of this removal experiment, it was found that the air washer 8
It can be seen that a significant proportion of the gaseous chemical contaminants were removed in, and that the remaining gaseous chemical contaminants were almost completely removed in the chemical filters 12 and 13.

In the apparatus of the above-described embodiment, the temperature of the air to be treated is lowered by the latent heat of evaporation of the water in the air washer 8 and the humidity is increased. Therefore, the air is heated by the reheater 11 to reduce the relative humidity. However, as shown in FIG. 5, the sensible heat exchanger 22 that straddles the upstream and downstream sides of the air washer 8 is provided.
Thus, the heat of the air to be processed on the upstream side of the air washer may be recovered to raise the temperature of the air to be processed on the downstream side of the air washer, thereby reducing the heating energy of the reheater 11.

FIG. 6 shows the change in the state of the air to be treated in the case where the sensible heat exchanger 22 is provided as indicated by a solid line on the psychrometric chart. The change in the state of the air to be processed when there is no air is indicated by a broken line. In the figure, denotes the upstream side of the heat recovery section of the sensible heat exchanger 22,
Indicates the state of each air at the inlet of the air washer 8, the outlet thereof, the inlet of the reheater 11, and the outlet thereof.
B shows the state of air at the inlet and outlet of the reheater when no sensible heat exchanger is provided, and both the operation of the air-conditioning cooler 9 and the heater 10 are stopped.

In the psychrometric chart of FIG. 6, Q ₁ and Q ₂ correspond to the amounts of heat consumed in the reheater 11 with and without the sensible heat exchanger, respectively, and the sensible heat exchanger is provided. This shows that the energy consumption in the reheater can be significantly reduced.

In the psychrometric chart, W ₁ and W ₂ correspond to the amount of pure water evaporated in the air washer 8 with and without the sensible heat exchanger, respectively. It can be seen that the pure water consumption can also be reduced by this.

Therefore, when the sensible heat exchanger 22 is provided to recover the heat of the air to be treated on the upstream side of the air washer and the temperature of the air to be treated on the downstream side is raised, the reheater 1
1 can reduce not only the heating energy, but also the consumption of pure water, and can significantly reduce the running cost.

In the embodiment described above, the air washer 8
Was provided with one element 14,
As shown in FIG. 7, the air washer 23 may include two elements.

In this air washer 23, a first element 24a and a second element 24b are arranged in series in the front-rear direction of the flow of the air to be treated, and the bottom of each element is a water tank 25a, 25b. It is immersed in.

One end of a water supply pipe 28 provided with a pump 27 in the middle is connected to the bottom of the water tank 25b.
8 is branched into branch pipes 30a and 30b each provided with a valve 29a and 29b in the middle.
The other end of Oa is directly connected to a watering header 31a provided above the first element 24a.
The other end of the branch pipe 30b is connected to a sprinkling header 31b provided above the second element 24b via a water purification device 32.

A water supply pipe 33 is connected in the middle of the branch pipe 30a to supply tap water constantly so that the concentration of pollutants in the water tank 25a does not increase. From the outside. Further, tap water is supplied to the water tank 25b by a water supply pipe 26. For example, a ball tap type valve (not shown) is provided in the middle of the water supply pipe,
When the water level in the water tank 25b drops, tap water is supplied from a water supply pipe, and excess water in the suction tank 25b is discharged from the overflow pipe 35 to the outside.

The first element 24a is filled with tap water from the water supply pipe 33 and water passed from the water tank 25b through the water supply pipe 28 and the branch pipe 30a by the driving of the pump 27 to the watering header 31.
a, and water in the water tank 25b is sprayed to the second element 24b from the watering header 31b via the water supply pipe 28, the branch pipe 30b, and the water purification device 32. That is, tap water and water in the water tank 25b are sprayed on the first element 24a, and pure water purified by the water purification device 32 is sprayed on the second element 24b.

Although the tap water and the water in the water tank 25b are sprayed on the first element 24a, if the quality of the tap water is better than the quality of the water in the water tank 25a, the branch pipe 30a may be used. The valve 29a is closed to supply only tap water from the water supply pipe 33 to the first element.

When the air to be treated passes through the first element 24a, it comes into contact with water flowing down the first element 24a to remove water-soluble gaseous chemical contaminants in the air to be treated to some extent. When passing through the second element 24b, the remaining water-soluble gaseous chemical contaminants are removed by contacting the pure water flowing down the second element.

In the air washer 23 having the above-described structure, since two elements are provided, the ability to remove gaseous chemical contaminants is not limited to being higher than that of a single element. In this case, since the air to be treated comes into contact with water and the absolute humidity rises, the amount of pure water evaporated in the second element becomes small, and hence the amount of pure water used becomes small, and the initial cost and running cost are high. There is also a great merit that the load on the liquefier can be reduced.

Although the description has been given of the case where the elements are provided in the first and second two stages, the elements may be provided in three or more stages. In this case, at least the elements of the first stage are provided. Tap water is sprayed, and pure water is sprayed on at least the last stage element.

[0036]

According to the gaseous chemical pollutant removing apparatus of the present invention, since the element of the air washer is made of a fiber material having water retention and ventilation, the air washer can be separated from the air to be treated. The contact area is large, and therefore the removal efficiency of gaseous chemical pollutants is large, and the element can be made compact.

Further, since the air washer has water retention, the residence time of water in the element becomes longer and the amount of water scattered is extremely small, so that the amount of pure water sprayed on the element is greatly reduced. The size can be reduced, and the running cost can be reduced.

The chemical filter is a filter material in which a carbon fiber as a base material is impregnated with a chemical adsorbent and is folded in a casing and accommodated therein. Therefore, the chemical filter can be made lightweight and compact. Can be replaced simply by replacing the filter material with the casing, so that maintenance can be easily performed.

Therefore, both the air washer and the chemical filter can be made compact and can be accommodated in one casing to save the space of the entire apparatus. For example, in the case of an apparatus having a processing capacity of 100 m ³ / min, The overall size of the device can be about 1.6 mx 4.8 mx height 2.4 m, and the initial costs such as transportation costs and construction costs of the device can be reduced.

In addition, by providing a plurality of elements in the air washer in series, not only the removal rate of gaseous chemical pollutants is improved, but at least the first-stage element is sprayed with tap water other than pure water. In addition, since the air to be treated, which has increased humidity in the preceding element, passes through the element to which pure water is sprayed, the amount of pure water to be sprayed and the amount of evaporation are small, and the running cost for supplying pure water is reduced. Can be remarkably reduced as compared with the conventional one.

Further, with the sensible heat exchanger, the amount of heat for heating in the reheater can be reduced and energy saving can be achieved.
In addition, since a cooling device and a heating device for air conditioning can be provided at appropriate places in the casing of the removing device, there is no need to provide a separate facility for air conditioning, and the installation space can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing an embodiment of an apparatus according to the present invention.

FIG. 2 is a perspective view showing an element for an air washer in a partially broken manner.

FIG. 3 is a perspective view showing an example of a chemical filter.

FIG. 4 is a table showing the results of an experiment for removing gaseous chemical pollutants.

FIG. 5 is a system diagram of an apparatus of the present invention including a sensible heat exchanger.

FIG. 6 is a psychrometric chart showing a state of air to be treated in each part of the apparatus of the present invention including a sensible heat exchanger.

FIG. 7 is a configuration diagram of an air washer including two elements.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Casing 1A Lower chamber 1B Upper chamber 2 Horizontal partition plate 2a Opening 3 Air inlet 4 Air outlet 5 Pre-filter 6 Heater 7 Blower 8 Air washer 9 Air conditioner cooler 10 Air conditioner heater 11 Reheater 12, 13 Chemical Filter 14 Element of air washer 15 Watering header 16 Water tank 17 Water supply pipe 18 Water pump 19 Water supply pipe 20 Filter material 21 Casing 22 Sensible heat exchanger 23 Air washer 24a, 24b Element 25a, 25b Water tank 26 Communication pipe 27 Water pump 28 Water pipe 29a, 29b Valve 30a, 30b Branch pipe 31a, 31b Sprinkler header 32 Purifier 33 Water supply pipe 34, 35 Overflow pipe

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 2, 1998 (1998.12.
2)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0030

[Correction method] Change

[Correction contents]

A water supply pipe 33 is connected in the middle of the branch pipe 30a to supply tap water constantly so that the concentration of pollutants in the water tank 25a does not increase. From the outside. Further, tap water is supplied to the water tank 25b by a water supply pipe 26. For example, a ball tap type valve (not shown) is provided in the middle of the water supply pipe,
When the water level in the water tank 25b drops, tap water is supplied from a water supply pipe, and excess water in the water tank 25b is discharged from the overflow pipe 35 to the outside.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction contents]

Further, with the sensible heat exchanger, the amount of heat for heating in the reheater can be reduced and energy saving can be achieved.
Further, since it is possible to Ru with a condenser and a heater for air conditioning in casing place of the removal device, there is no need to provide a separate facility for air conditioning, it is possible to occupy not the installation space small.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing an embodiment of an apparatus according to the present invention.

FIG. 2 is a perspective view showing an element for an air washer in a partially broken manner.

FIG. 3 is a perspective view showing an example of a chemical filter.

FIG. 4 is a table showing the results of an experiment for removing gaseous chemical pollutants.

FIG. 5 is a system diagram of an apparatus of the present invention including a sensible heat exchanger.

FIG. 6 is a psychrometric chart showing a state of air to be treated in each part of the apparatus of the present invention including a sensible heat exchanger.

FIG. 7 is a configuration diagram of an air washer including two elements.

[Description of Signs] 1 casing 1A lower chamber 1B upper chamber 2 horizontal partition plate 2a opening 3 air inlet 4 air outlet 5 pre-filter 6 heater 7 blower 8 air washer 9 air conditioner cooler 10 air conditioner heater 11 reheat Apparatus 12, 13 Chemical filter 14 Element of air washer 15 Sprinkling header 16 Water tank 17 Water supply pipe 18 Water pump 19 Water supply pipe 20 Filter material 21 Casing 22 Sensible heat exchanger 23 Air washer 24a, 24b Element 25a, 25b Water tank 26 Water supply pipe 27 Water pump 28 Water supply pipe 29a, 29b Valve 30a, 30b Branch pipe 31a, 31b Watering header 32 Purifier 33 Water supply pipe 34, 35 Overflow pipe

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) B01D 53/81 (72) Inventor Masayoshi Yamamoto 1-40-16 Fujimidai, Kunitachi-shi, Tokyo F-term (reference) 4D002 AA02 AA13 BA02 BA04 BA12 BA13 CA04 CA07 CA13 DA35 DA70 EA02 EA13 GA03 GB03 HA08 4D020 AA06 AA10 BA23 BA30 BB03 BB07 BC06 BC10 CB28 CB33 CC01 CC09 CC13 CC14 DA01 DB02

Claims (6)

[Claims] An air blower, an air washer and a chemical filter are provided in a casing having an air inlet and an air outlet, and the air to be processed flows in the order of the air washer and the chemical filter by driving the blower. Equipped with an element made of fiber material that has water retention and ventilation, the air to be treated flowing through the element is brought into contact with water sprayed from above on the element to remove gaseous chemical pollutants in the air to be treated Gaseous chemical pollutant removal equipment. 2. A blower, an air washer and a chemical filter are provided in a casing having an air inlet and an air outlet, and the air to be processed is circulated in the order of the air washer and the chemical filter by driving the blower. Equipped with an element made of fiber material that has water retention and ventilation, the air to be treated flowing through the element is brought into contact with water sprayed from above on the element to remove gaseous chemical pollutants in the air to be treated In addition, the chemical filter is a gaseous chemical pollutant removing apparatus comprising a filter casing formed by impregnating a chemical adsorbent into activated carbon fiber as a base material and forming the filter material into a sheet shape in a filter casing. 3. A blower, an air washer and a chemical filter are provided in a casing having an air inlet and an air outlet, and the air to be processed is circulated in the order of the air washer and the chemical filter by driving the blower. A plurality of elements made of fiber material having water retention and ventilation are provided in series, and pure water is sprinkled on at least the elements in the final stage air washer, but pure water is sprayed on at least the elements in the first stage air washer. Water other than water is sprinkled, and the air to be treated flowing through each element is brought into contact with water sprayed from above onto the element to remove gaseous chemical pollutants in the air to be treated. apparatus. 4. A blower, an air washer and a chemical filter are provided in a casing having an air inlet and an air outlet, and the air to be processed is circulated in the order of the air washer and the chemical filter by driving the blower. A plurality of elements made of a fiber material having water retention and ventilation are provided in series, and pure water is sprinkled on at least the element in the last-stage air washer, but pure water is sprayed on at least the element in the first-stage air washer. Water other than water is sprinkled, the air to be treated flowing through each element is brought into contact with water sprayed from above onto the element to remove gaseous chemical contaminants in the air to be treated, and the chemical filter is Activated carbon fiber as a base material is impregnated with a chemical adsorbent and formed into a sheet-shaped filter material in a filter casing. Gaseous chemical decontamination apparatus comprising as a configuration in which capacity. 5. The gaseous chemical pollutant removal apparatus according to claim 1, further comprising a sensible heat exchanger for exchanging heat of the air to be processed before and after the air washer in the casing. 6. The gaseous chemical pollutant removal apparatus according to claim 1, wherein at least one of an air cooler for air conditioning and an air heater is disposed at an appropriate position in the casing.