JP2000354727A - Gas purifying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reduce gas passing resistance while obtaining high gas purifying performance. SOLUTION: A water spraying means 6 for spraying washing water W to the subject passing gas A to be purified is provided, and many heat-transfer members 4a and 4b for cooling and dehumidifying the passing gas A by subjecting the passing gas A and a refrigeration medium R to heat-exchange are arranged in dispersed state at the water spraying area of the water spraying means 6. Preferably, the device constitution in which a heat-transfer pipe 4a of the cooling coil 4 for subjecting the passing gas A and the refrigeration medium R to the heat exchange or a fin 4b incidental to the heat-transfer pipe 4a is used as the heat-transfer member and the gas passing area of a cooling coil 4 is used as the water spraying area of the water spraying means 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas purifier used for removing chemical components in the air such as ammonia and chlorine.

[0002]

2. Description of the Related Art Conventionally, when gas purification and gas cooling are required for purifying circulating air in a clean room and removing the indoor sensible heat load of the clean room, the gas to be purified is converted to a dry chemical. Purification is performed without causing an increase in humidity by passing through a filter, and then the purified gas is cooled by passing through a dry cooling coil (coil that removes only sensible heat), that is, a gas dehumidification process is derived. There is a method in which gas purification and cooling are performed in a state in which gas generation is avoided.

[0003] Alternatively, in the case of using a gas purification method by water spraying, while the absolute humidity of the gas is significantly increased by water spraying, the gas after water purification is sprayed with a wet cooling coil (sensible heat and latent heat). (A coil for removing water) to cool and dehumidify the water, thereby cooling the gas while purifying it by spraying water and restoring the humidity to a low humidity side.

[0004] In the latter method, in order to improve the purification performance, a contact layer between the washing water and the passing gas is increased by providing a gas-permeable filling layer in a water spray area for the passing gas.

[0005]

However, in the former method using a dry chemical filter, the following (a) to (c) are used.
There is a problem.

(A) Since the chemical filter needs to be replaced before the filter breaks through, the burden of filter management is large, and the operation is stopped to replace the filter in a 24-hour clean room or the like. Need to be done.

(B) Dust and chemical components are released from the chemical filter itself (for example, fatty acids and organic substances are released from the glue and packing which constitute the filter). There is also the danger that the collected chemical components will be released again from the filter that is approaching the transient state,
In this regard, the reliability in terms of gas purification is low.

(C) Since the gas is passed through the cooling coil following the chemical filter, the ventilation resistance (in other words, the pressure loss of the passing gas) is large, and the power for transporting the gas is increased.

On the other hand, in the latter method of purifying gas by water spraying, the above-mentioned problems (a) and (b) can be avoided because a chemical filter is not used, but the following problem (d) is also involved in ventilation resistance. There is.

(D) A high gas-liquid contacting efficiency cannot be secured by merely spraying water on the passing gas, and the purification performance is limited to a low level. In this case, since the gas is passed through the cooling layer following the packed bed in the water sprinkling area, the gas flow resistance (pressure loss of the passing gas) increases, and the gas is conveyed. Power increases.

In view of the above circumstances, a main object of the present invention is to effectively solve the above-mentioned problems by adopting a rational device configuration in a gas purification system by water spray.

[0012]

Means for Solving the Problems [1] In the invention according to the first aspect, a water spraying means is provided for spraying washing water on the passing gas to be purified, and the passing gas, the cooling medium and the cooling medium are provided in a water spray area of the water spraying means. Are heat-exchanged to cool and dehumidify the passing gas, and a large number of heat transfer members are arranged in a dispersed state.

In other words, in this configuration, while purifying the gas and cooling the gas are required, the cleaning water is sprayed on the passing gas in the sprinkling area to remove components such as chemical components in the passing gas. To purify the passing gas by spraying and washing water, and in parallel with this, the passing gas is cooled and dehumidified by heat exchange with a cooling medium by a large number of heat transfer members dispersedly arranged in the spray area. The passing gas is cooled while suppressing the rise in absolute humidity due to watering.

In addition, a large number of heat transfer members dispersedly disposed in the water spray area are made wet by spray cleaning water, so that a group of these heat transfer members dispersedly distributed for improving gas-liquid contact efficiency. It also functions as a layer to ensure high contact efficiency between the spray cleaning water and the passing gas.

That is, according to the above configuration, since a purifying method using water spray is adopted, filter replacement as in a purifying method using a chemical filter is not required, the apparatus can be easily managed, and a 24-hour clean room In such a case, it is possible to avoid the need to stop the operation for replacing the filter.

In addition, since there is no generation of dust or chemical components from the filter itself which is observed in the purification method using a chemical filter, a mode in which the heat transfer members dispersed in the water spray area also function as a gas-permeable filling layer. As a result, the contact efficiency between the spray cleaning water and the passing gas is ensured to be high, and together with these, high purification performance can be obtained.

Since the passing gas is cooled and dehumidified by the heat transfer members while the heat transfer members distributed in the water spray area also function as a packed layer for improving the gas-liquid contact efficiency, a purification method by water spray is used. In order to avoid an increase in the absolute humidity of the passing gas due to water spraying, it is not necessary to provide a wet cooling coil separately downstream of the water spray area in the gas passage, Even if a wet cooling coil is provided on the downstream side, it can be done with a small amount, so that compared to the conventional method in which gas passes through the wet cooling coil following the packed bed in the water sprinkling area, the dry cooling coil is also used. Compared with the conventional method of passing gas through a dry-type cooling coil following a chemical filter, the airflow resistance (pressure loss of passing gas) can be reduced while achieving high purification performance. It is possible to reduce the power required to feed.

[2] In the invention according to claim 2, claim 1
In carrying out the invention according to the present invention, a heat transfer tube of a cooling coil for exchanging heat between a passing gas and a cooling medium or a fin attached to the heat transfer tube is used as the heat transfer member, and a gas passage area of the cooling coil is dispersed by the water spraying means. To water area.

In other words, according to this configuration, the transmission of the cooling coil itself can be achieved simply by adding an appropriate watering means such as a watering nozzle for spraying the cleaning water to the gas passage area of the general cooling coil. An apparatus according to the first aspect of the present invention can be configured by using a heat tube or a fin as the heat transfer member, thereby facilitating the manufacture of the apparatus and reducing the cost.

Further, since the fins of the cooling coil generally adopt a structure in which a large number of thin plate-shaped fins are juxtaposed at intervals of several mm, if the fins of the cooling coil are used as the heat transfer member, the fins of the spray cleaning water may be used. It is expected that the removal target components such as chemical components in the passing gas will collide against the plate surface of the fins in its own state by its own Brownian motion and efficiently capture it, thereby further improving the purification performance. it can.

[3] In the invention according to the third aspect, the first aspect
In implementing the invention according to (2), a cooling coil for dew point control for exchanging heat between the passing gas and the cooling medium to cool and dehumidify the passing gas to a target absolute humidity is disposed downstream of the water spray area in the gas passage path. I do.

In other words, simply by cooling and dehumidifying the passing gas concurrently with the water spray by the heat transfer member arranged in the water spray area,
Although it is difficult to accurately adjust the passing gas to the required absolute humidity due to the effect of water spraying, if a cooling coil for dew point control is provided downstream of the watering area as described above, this cooling coil for dew point control By adjusting the amount of cooling and dehumidification, the passing gas after purification can be accurately adjusted to the target absolute humidity without being affected by water spray.

Further, if the cooling coil for controlling the dew point is provided, it is possible to efficiently capture the accompanying water droplets in the gas passing from the sprinkling area by using the heat transfer tubes and the fins as draining means. Accordingly, it is possible to prevent water droplets from being contained in the gas after the treatment, and it is possible to reduce the size of the dedicated draining means even if additional dedicated draining means is additionally provided.

Since the rise in the absolute humidity of the passing gas due to the water spray is suppressed by cooling and dehumidification by the heat transfer member disposed in the water spray area, the dew point control cooling coil is provided downstream of the water spray area in the conventional method. Compared with the wet cooling coil to be deployed, the required dehumidifying capacity can be small and small,
This does not cause a significant increase in airflow resistance. For this reason, even if this cooling coil for dew point control is provided,
The effect of reducing the ventilation resistance as a whole can be sufficiently obtained.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a water purifying type gas purifying apparatus. An inlet of a gas A to be purified (for example, air containing a high concentration of a chemical component such as ammonia, chlorine, NOx and SOx) is introduced into a casing 1 of the apparatus. 2 and outlet 3 for treated gas A ″
And a fin tube type main cooling coil 4 for passing the gas A to be purified introduced from the inlet 2 is provided inside the apparatus casing 1, and a gas passage area of the main cooling coil 4 (ie, A plurality of water spray nozzles 6 for spraying the pure water W supplied from the water supply passage 5 are provided with the water transfer area as a spray area of the heat transfer pipes 4a and the fins 4b.

A fin tube type dew point controlling cooling coil 7 for passing the gas A to be purified following the main cooling coil 4 is provided inside the apparatus casing 1.
The gas A ″ that has passed through the dew point controlling cooling coil 7 is sent out from the outlet 3 by the built-in fan 8 as a processed gas.

9 is an adjusting valve for adjusting the supply amount of the cooling medium R (cold water or brine) to the main cooling coil 4 to adjust the cooling dehumidification amount of the passing gas A in the main cooling coil 4, 10 is a dew point control It is an adjustment valve for adjusting the supply amount of the cooling medium R ′ (cold water or brine) to the cooling coil 7 for use, thereby adjusting the cooling dehumidification amount of the passing gas A ′ in the cooling coil 7 for controlling the dew point.

In other words, in this purifying apparatus, purifying and cooling of the gas are required, but pure water W is sprayed in the gas passage area of the main cooling coil 4 to purify the gas to be purified passing through the main cooling coil 4. The removal target components such as the chemical components in the gas A are trapped in the spray water W to purify the purification target gas A, and at the same time as the purification, the passing gas A is cooled and dehumidified by the main cooling coil 4 to spray water. The purification target gas A is cooled while suppressing an increase in the absolute humidity due to the above.

The heat transfer tube 4a in the main cooling coil 4
The heat transfer tubes 4a and the fins 4b are brought into a wet state by the spray water W to make the heat transfer members and the fins 4b (that is, a large number of heat transfer members that perform heat exchange of the passing gas A with the cooling medium R to cool and dehumidify).
The group b also functions as a gas-permeable filling layer for improving the gas-liquid contact efficiency, thereby ensuring high contact efficiency between the spray water W and the passing gas A, thereby obtaining high purification performance.

The gas A ', which has been purified and cooled as described above in the main cooling coil 4, is subsequently passed through the cooling coil 7 for controlling the dew point, thereby cooling and dehumidifying the cooling coil 7 for controlling the dew point. By adjusting the amount, the absolute humidity of the gas A ″ to be sent out as the gas after the treatment is accurately adjusted to a target value (for example, the absolute humidity equal to the gas A to be purified before the treatment introduced from the inlet 2), and the dew point With the heat transfer tubes 7a and the fins 7b of the control cooling coil 7 used as draining means, accompanying water droplets contained in the passing gas A 'from the main cooling coil 4 are efficiently captured, and the treated gas A "
Prevents the inclusion of water droplets.

The spray water W (that is, the water capturing the component to be removed in the gas A to be purified) which falls after the spraying of the main cooling coil 4 into the gas passage area is cooled by the cooling coils 4 and 7. Together with the condensed water generated by the dehumidification, it is received by a drain pan 11 at the bottom of the casing and discharged to the outside of the casing through a drainage passage 12. Then, the wastewater W 'is completely discarded, or the wastewater W' is circulated and supplied to the watering nozzle 6 by adjusting the concentration by partially disposing and supplying fresh pure water under the concentration control by detecting the electric conductivity. I do.

FIG. 2 shows a clean room facility showing an example of installation of the above-mentioned gas purifying apparatus J. A high-performance filter 14 (HEPA filter or ULPA filter) is juxtaposed on the ceiling of a target room 13 and a circulation fan 15 Air supply chamber 16 → target room 13 → underfloor return air chamber 17 → return air passage 1
In circulating the air A in the order of 8 → the ceiling air supply chamber 16, dust and the like are removed from the supply air A to the target room 13 by the high performance filter 14 at the ceiling.

In this clean room facility, one or more of the above-mentioned gas purifying devices J are arranged at, for example, the locations A and B in FIG. By passing some or all of the air A through the gas purification device J, chemical components such as ammonia and chlorine are collected and removed from the circulating air A, and the concentration of the chemical components in the target chamber 13 is kept at a predetermined value or less.

In FIG. 2, reference numeral 19 denotes an auxiliary dry cooling coil for cooling the circulating air A, which is provided when the sensible heat load in the target chamber 13 cannot be completely removed only by the gas cooling function of the gas purification device J. .

[Alternative Embodiment] In the above-described embodiment, since a large number of heat transfer members for exchanging heat between the passing gas A and the cooling medium R to cool and dehumidify the passing gas A are arranged in the water spray area in a distributed manner. In the embodiment, the gas passage area of the coil 4 is used as the water spray area of the water spraying means 6, and the heat transfer tubes 4a and the fins 4b of the cooling coil 4 are used as the above-mentioned many heat transfer members. The specific structure of the heat transfer member can be variously changed. For example, as shown in FIG. 3, a large number of double plate-like heat transfer members 20 are juxtaposed in the water spray area and the adjacent double plate-like heat transfer members In a structure in which the passage between the members 20 is a passage for the gas A to be purified, the passing gas A is cooled and dehumidified by passing the cooling medium R through the internal gap between the plates of the double plate-shaped heat transfer members 20. Such a structure may be adopted.

In the above-described embodiment, an example has been described in which pure water is used as the spray cleaning water W for capturing the components to be removed in the gas A to be purified. However, the cleaning water W to be sprayed is not limited to pure water. Instead, general tap water may be used as spray cleaning water, or water whose components have been adjusted to efficiently collect a specific component to be removed in the purification target gas A may be used as spray cleaning water.

In the above-described embodiment, the water spray nozzle 6 is used as the water spray means. However, various types of water spray means for spraying the washing water W to the passing gas A can be used. As shown in FIG. 3, the washing water W may be dropped from a large number of holes 22 formed in the bottom wall of the water tank 21 and sprayed on the passing gas A.

In the above-described embodiment, the counter flow system in which the spray direction of the washing water of the water spray nozzle 6 is opposed to the passing gas A is employed. If the parallel flow method is adopted in which the flow direction is the same as the passing direction of the passing gas A, the reduction of the ventilation resistance can be further promoted.

A large number of heat transfer members 4 distributed in the watering area
a, 4b, and 20 are the same cooling medium as the cooling medium R for exchanging heat with the passing gas A and the cooling medium R 'for exchanging heat with the passing gas A' in the cooling coil 7 for controlling the dew point disposed downstream of the water spray area. A medium may be used, or a different cooling medium may be used.

In order to adjust the passing gas A 'to the target absolute humidity by the cooling and dehumidification in the dew point controlling cooling coil 7, the target absolute humidity is limited to the absolute humidity equal to the absolute humidity of the gas A to be purified before the treatment. Instead, the target absolute humidity may be an absolute humidity higher than the absolute humidity of the purification target gas A before the treatment or an absolute humidity lower than the absolute humidity of the purification target gas A before the treatment.

When high-precision absolute humidity adjustment is not required for the processed gas, the cooling coil 7 for controlling the dew point may be omitted.

The gas purification apparatus according to the present invention can be used not only for air purification but also for various gas purifications, and can be used not only in clean room equipment but also in various fields requiring gas purification.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a gas purification device.

FIG. 2 is a configuration diagram of a clean room facility showing an installation example of a gas purification device.

FIG. 3 is a configuration diagram of a gas purification device showing another embodiment.

[Explanation of symbols]

 Reference Signs List 4 cooling coil 4a heat transfer tube, heat transfer member 4b fin, heat transfer member 6 water spraying means 7 cooling coil for dew point control 20 heat transfer member 22 water spraying means A gas to be purified R cooling medium R 'cooling medium W washing water

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takahiro Watanabe 2-6-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo F-term Co., Ltd. F-term (reference) 4C080 AA03 BB02 CC02 CC03 CC07 CC08 HH03 KK06 KK08 LL02 LL08 MM01 NN01 QQ17 4D020 AA10 BA23 BB03 BC10 CB25 CC09 CD01 CD02 DA01 DB02 DB03 DB20 4D052 AA00 AA08 BA03 BA05 BB02 FA08 GA01 GA03 GB00 GB02 GB03 GB05 GB06

Claims (3)

[Claims] 1. A water spraying means for spraying washing water to a gas to be purified and a plurality of heat transfer means for exchanging heat between the gas and a cooling medium in a water spray area of the water spraying means to cool and dehumidify the gas passing therethrough. A gas purification device in which members are arranged in a dispersed state. 2. A heat transfer tube of a cooling coil for exchanging heat between a passing gas and a cooling medium or a fin attached to the heat transfer tube is used as the heat transfer member, and a gas passage region of the cooling coil is used as a water spray region of the water spraying means. The gas purifying apparatus according to claim 1, wherein 3. A cooling coil for controlling a dew point for exchanging heat between the passing gas and a cooling medium to cool and dehumidify the passing gas to a target absolute humidity is disposed downstream of the water spray area in the gas passage path. Item 3. The gas purifying apparatus according to Item 1 or 2.