JP4441728B2 - Pollutant removal device - Google Patents

Description

  The present invention relates to a contaminant removal apparatus that removes contaminants present in air in a clean room or the like.

  In a clean room that manufactures semiconductors, liquid crystals, etc., in areas where semiconductor and liquid crystal cleaning processes, exposure processes, coating film processes, etc. are performed, organic chemical gases evaporated from chemicals used in the production process, etc. Is contained in the air. This organic substance in the air has an adverse effect on the working environment of the clean room and the product yield, and therefore needs to be removed. In the patent document 1, the present applicant has proposed a method for removing contaminants such as organic substances in the air from a clean room. FIG. 3 is an explanatory diagram of the organic substance removing method described in Patent Document 1.

  In FIG. 3, the clean room 1 is installed in a manufacturing factory for semiconductors, liquid crystals, and the like. In the manufacturing apparatus 2, for example, a semiconductor or a liquid crystal is manufactured. The wet pollutant gas removing device 3 makes contact between air to be removed against pollutants such as organic substances and makeup water such as pure water, and removes pollutants by absorption or dissolution in the makeup water. . In this way, the wet pollutant gas removal device 3 sucks the indoor air (return air A) of the clean room 1 containing pollutants such as organic substances leaked from the manufacturing device 2 to remove the pollutants, and to clean the air ( Supply air D) is circulated in the clean room 1 by the blower fan 6. At this time, the temperature of the air can be raised to a temperature required in the clean room 1 by a hot water coil or the like.

  As described above, the room air in the clean room 1 is sucked by the wet pollutant gas removing device 3 to remove the specific pollutants existing in the air, and the cleaned air is circulated to the clean room 1 again. In such a wet pollutant gas removing device 3, pure water is cooled with cold water in the spray water tank 5, and the low temperature water is used to inject from the spray nozzle 4 in the spray chamber 7 to contact the processing air. As a result, the contaminant removal performance is improved. The reason why low-temperature water is used is that low-temperature water has a higher substance absorption efficiency, and further does not humidify the air returned to the clean room. The treated air is used for air conditioning (cooling and humidity control) in the clean room.

  A filter 8 and a filter 9 are provided at the inlet and outlet of the spray chamber 7 in order to remove microparticles containing bacteria. The filter 8 uses, for example, a high performance filter (High Efficiency Air Filter) or a HEPA filter (High Efficiency Particulate Air Filter). Further, a HEPA filter is used as the filter 9.

  By the way, in the wet pollutant gas removal apparatus 3, microorganisms (bacteria) propagate on the spray nozzle 4, its piping, the inner wall surface of the spray chamber 7, and the like under the following operating conditions. That is, (1) the internal temperature of the spray chamber 7 is high. (2) Bacterial bacteria enter the spray chamber 7. (3) The concentration of the organic substance sucked into the spray chamber 7 is very high, and it tends to be a diet of bacteria.

  If these conditions are met and bacteria are propagated on the spray nozzle 4, its piping, the inner wall surface of the spray chamber 7, etc., problems such as a decrease in the removal performance of contaminants and a decrease in the amount of spray water occur. Various countermeasures have been taken to prevent such bacterial growth, and regular maintenance is required. As an example of the countermeasure, the air temperature in the spray chamber 7 is lowered.

JP 2000-33221 A

  In the conventional apparatus shown in FIG. 3 described in Patent Document 1, pure water, that is, makeup water, is once supplied into the spray water tank 5 and then pumped into the spray chamber 7 by a pump and injected from the spray nozzle 4. In this way, contaminants in the processing air are removed. This is because, as described above, the spray water tank 5 has a low temperature due to cold water, and the temperature of pure water is lowered in the spray water tank 5 and then sprayed on the treatment air to prevent the growth of bacteria. .

  In the configuration of FIG. 3, the temperature of the processing air in the spray chamber 7 is lowered by circulating water (pure water) that has been cooled to low temperature with cold water, but there is a limit to reducing the temperature of the processing air only by circulating water. There is. For this reason, it is conceivable to provide cooling means for lowering the temperature of the processing air in the spray chamber 7 and to cool the cooling means with cold water.

  At this time, the cold water is supplied to the wet pollutant gas removing device 3 so that the water temperature and the air temperature are lowered at each necessary place and then returned to a predetermined place through the pipe. When the temperature difference between the inflow temperature and the outflow temperature of the cold water is large, the diameter of the pipe through which the cold water flows may be small, so that the cost can be reduced. For this reason, it is conceivable that the low-temperature cold water that has flowed into the wet pollutant gas removal device 3 is supplied to the cooling means installed in the spray chamber 7 and heated to a certain extent before being discharged to a predetermined location.

  As means for raising the cold water temperature as described above, for example, the following configuration can be considered. That is, in the example of FIG. 3, a heating coil may be installed on the rear side of the blower fan 6, that is, on the side close to the clean room 1 in order to increase the temperature of the air flowing into the clean room 1. This is a process for increasing the temperature of the processing air processed at a low temperature in the spray chamber 7 to the air conditioning temperature required in the clean room 1. A heat exchanger is connected to the heating coil. The hot water of a predetermined temperature is supplied from the manufacturing means to the heating coil, and the cold water is supplied to the heat exchanger installed in the return path to the hot water manufacturing means, thereby increasing the temperature of the cold water to the predetermined temperature, and then Supply to cooling means.

  However, when the temperature of the cold water is raised through the heat exchanger connected to the heating coil for air conditioning in this way, the energy of the hot water supplied to the heating coil is taken and the temperature of the hot water is lowered. For this reason, in the hot water production means, the return hot water must be heated again to a predetermined temperature, so that there is a problem that the energy consumption of the heat source increases.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a pollutant removal apparatus capable of effectively using a heat source and suppressing bacterial growth in a spray chamber.

In order to achieve such an object, the pollutant removal apparatus of the present invention includes a spray chamber having a plurality of rows of spray nozzles, a circulating water tank connected to the spray chamber by a water collecting pipe, the spray nozzle and the circulation. A pollutant removing device that connects a water tank with a pipe, removes pollutants in the processing air flowing into the spray chamber by circulating water ejected from the spray nozzle, and sends the air to the air conditioning chamber. ,
Make-up water flows into the first heat exchanger to which cold water is supplied through the second heat exchanger to which the waste water from the circulating water tank is supplied, and is supplied from the first heat exchanger to the spray nozzle. ,
The makeup water is directly supplied to the spray chamber without going through the circulating water tank and injected from one of the spray nozzles,
A cooling means for cooling the inflowing air with cold water is provided in the spray chamber,
The cold water cools parts installed in the air-conditioning room, and then flows into a third heat exchanger into which the circulating water flows, and supplies the cooling means from the third heat exchanger to the replenishment unit. The first heat exchanger to which water and cold water are supplied and the third heat exchanger are connected in series by a pipe .

In the present invention, the cold water is supplied to a dehumidification coil of a component installed in the air conditioning chamber, and the cooling coil is cooled through the third heat exchanger to which the circulating water is supplied after cooling the dehumidification coil. It is characterized in that the temperature of the chilled water is gradually increased.

  Further, the present invention is characterized in that a heating coil to which hot water is supplied is provided in the air conditioning room.

In the present invention, low-temperature cold water supplied to the pollutant removal device is circulated so as to gradually increase the temperature, contrary to the temperature gradient of the processing air, so that the temperature difference between the inflow side and the outflow side increases. I have to. At this time, the hot water supplied to increase the temperature of the processing air flowing into the air conditioning room is not used for increasing the temperature of the cold water, so that the heat source can be effectively used. Moreover, since the temperature difference between the inflow side and the outflow side of the cold water is set large, the diameter of the pipe through which the cold water flows can be reduced and the cost can be reduced. In this way, the energy required to cool the processing air from the clean room is arranged according to the required temperature, and heat exchange means are installed in series so that the cold water can be used from the lowest temperature to the highest temperature in the order of the highest energy. ing.
Furthermore, the makeup water by pure water is directly supplied to the spray chamber without going through the makeup circulation water tank. For this reason, the pure water is injected into the processing air while maintaining the purity, and the organic substance can be effectively removed.

  In addition, since the spray chamber is provided with a cooling means for the processing air and low temperature circulating water and make-up water are supplied to the spray chamber, the propagation of bacteria in the spray chamber can be suppressed. Therefore, maintenance (running) costs for removing bacteria can be reduced.

  In addition, since multiple heat exchangers are connected in series by piping, the amount of chilled water used is greatly increased compared to connecting heat exchangers in parallel while ensuring sufficient contaminant removal capacity. Can be reduced. As described above, since the piping cost can be reduced and the heat source capacity can be reduced by reducing the amount of cold water used, the entire building in which the pollutant removing device is installed can achieve a significant cost reduction. It is also possible to contribute to improving the global environment by saving cold water.

  Embodiments of the present invention will be described below. FIG. 2 is a schematic configuration diagram showing the overall configuration of the pollutant removal apparatus of the present invention, and FIG. 1 is a configuration diagram showing the configuration of the cold / hot water use portion in the pollutant removal apparatus of FIG. 1 and 2, reference numeral 50 denotes an air washer device (a spray chamber), which corresponds to the spray chamber 7 of FIG. Process air containing contaminants from the clean room (work room) flows into the air washer device 50. Reference numeral 66 denotes a HEPA filter installed at the inlet of the air washer device 50. A high performance filter may be installed instead of the HEPA filter.

  A cooling coil 68 cools the processing air that has passed through the HEPA filter 66. The cooling coil 68 is used as a dry coil in which bacteria do not easily propagate. For example, cold water of 12 ° C. is supplied to the cooling coil 68. When the cold water having such a temperature is supplied, the cooling coil 68 does not condense, so that the growth of bacteria on the surface of the cooling coil can be suppressed. In this way, a filter that removes microparticles containing bacteria is provided at the inlet of the air washer device 50, and a cooling coil is installed downstream of the filter to lower the temperature. Is preventing. Reference numeral 67 denotes a heat recovery coil provided along with the cooling coil 68.

  The air washer device 50 includes a plurality of processing chambers, that is, a pretreatment system 51, a spray 1 system 52, a spray 2 system 53, and a makeup water system 54 from the upstream side to the downstream side as viewed from the flow direction of the processing air. Is provided. In this example, the number of processing chambers to which the circulating water is supplied is 3 (4 including the section to which makeup water is supplied), but the number of processing chambers to which the circulating water is supplied is 4 It is possible to make it more than a few. By setting the number of processing chambers to four or more, organic substances in the processing air can be more effectively removed. In each processing chamber, spray nozzles 51a to 54a are provided. Low temperature water is injected from the spray nozzles 51a to 54a into the processing air flowing into the air washer device 50 to remove gas components having high solubility in water. 55 is a replenishment circulation water tank, which corresponds to the spray water tank of FIG. 3, and is connected to the air washer device 50 by water collecting pipes 71 to 74. In the present invention, the supplemental circulating water tank may be simply referred to as a circulating water tank.

  The supply circulation water tank 55 is divided into a first supply circulation water tank 55a and a second supply circulation water tank 55b. Reference numerals 56a and 56b denote first and second pumps, and 57a and 57b denote first and second water treatment filters. The first supplementary circulating water tank 55a supplies the circulating water to the spray nozzles 51a and 52a through the first pump 56a, the first water treatment filter 57a, and the pipe 83. In addition, the second replenishing circulating water tank 55b is configured to supply the circulating water to the spray nozzle 53a through the second pump 56b, the second water treatment filter 57b, the spray water heat exchanger 59b (third heat exchanger), and the pipe 85. Supply.

  The makeup water (G) using pure water is supplied to the makeup water drain heat exchanger 58 (second heat exchanger) through the pipe 80. The temperature of the supplied makeup water is set at, for example, 20 to 26 ° C., and the temperature is temporarily lowered by drainage of about 15 ° C. supplied from the first makeup circulation water tank 55a to the makeup water drain heat exchanger 58. The drainage from the makeup water drainage heat exchanger 58 is discharged to a predetermined location through a pipe 86. The makeup water whose temperature has been lowered by the makeup water drain heat exchanger 58 passes through the pipe 81 and is supplied to the makeup water heat exchanger 59a (first heat exchanger).

  The cold water (E) supplied by the pipe 90 is branched by the pipes 91 and 92. One pipe 91 is connected to a makeup water heat exchanger 59a, and the other pipe 92 is connected to a dehumidifying coil 63 described later. The make-up water is further treated with cold water by the make-up water heat exchanger 59a and supplied to the spray nozzle 54a from the pipe 82. The circulating water supplied from the second replenishment circulating water tank 55b to the spray nozzle 53a is also cooled by the cold water in the spray water heat exchanger 59b and supplied from the pipe 85 to the spray nozzle 53a. As described above, the makeup water and the circulating water that have been cooled to low temperature with cold water are supplied to the air washer device 50, so that the growth of bacteria in the air washer device 50 can be suppressed.

  The low-temperature water injected by the spray nozzles 53a and 54a is collected in the second supplementary circulating water tank 55b by the water collecting pipes 73 and 74, and the surplus recovered water flows into the first supplementary circulating water tank 55a. Circulating water from the first replenishing circulating water tank 55a is injected as low-temperature water by the spray nozzles 51a and 52a, and collected by the water collecting pipes 71 and 72 to the first replenishing circulating water tank 55a. A part of the recovered water flows out as drainage, and the organic components absorbed by the air washer device 50 are concentrated and discharged. Thus, since the circulating water supplied to the spray nozzles 51a and 52a from the first replenishment circulating water tank 55a is the recovered water once used by the spray nozzles 53a and 54a, the circulating water supplied from the spray nozzle 53a. Rather than the purity.

  In the air washer device 50, an eliminator 69 is installed on the downstream side of the spray nozzle 54a. The treated air from which the gas component having high solubility in water is removed by the spray nozzles 51a to 54a further passes through the eliminator 69, and the mist of the spray water is removed. An air conditioning chamber 60 is provided adjacent to the air washer device 50, and the processing air from which contaminants have been removed by the air washer device 50 flows into the air conditioning chamber (air conditioning chamber) 60.

  In the embodiment shown in FIGS. 1 and 2, the makeup water by pure water is directly supplied to the air washer device 50 without going through the makeup circulation water tank 55. For this reason, the pure water is injected into the processing air while maintaining the purity, and the organic substance can be effectively removed.

  The air conditioning chamber 60 is provided with a circulation fan 61, a HEPA filter 62, a dehumidifying coil 63, a cold recovery coil 64, and a heating coil 65. Each of these components is installed in the housing of the air conditioning chamber 60. By passing through the air washer device 50, the processing air that has been brought to a low temperature of about 12 ° C., for example, is reheated by the heating coil 65 to a predetermined temperature required for temperature adjustment of the clean room (work chamber), for example, 23 ° C. The processing air that has flowed into the air conditioning chamber 60 passes through the HEPA filter 62 and is purified, and the humidity is adjusted by the dehumidifying coil 63. Thus, since the dehumidifying coil 63 is provided in the air conditioning chamber 60, the humidity management of the supply air supplied to the clean room can be performed satisfactorily.

  In the embodiment shown in FIG. 1, hot water (F) is supplied to a heating coil 65 provided in the air conditioning chamber 60 from hot water producing means (not shown) to reheat the processing air. The temperature of the hot water (F) is set to 34 ° C., for example. Reference numeral 77 is a valve for adjusting the return hot water amount. The cold water flowing from the pipe 92 is supplied to the spray water heat exchanger 59b via the dehumidifying coil 63. 75 is a valve for adjusting the flow rate of cold water.

  The temperature of the cold water supplied from the pipe 90 is set to 7 ° C., for example, but is raised to about 10 ° C. through the dehumidifying coil 63. Furthermore, the temperature of the cold water is raised to about 12 ° C. by being supplied from the dehumidifying coil 63 to the spray water heat exchanger 59b. Therefore, cold water having a water temperature of about 12 ° C. is supplied to the cooling coil 68 through the pipe 94 so as to prevent dew condensation on the surface thereof. In the configuration of FIG. 1, the chilled water supplied to the apparatus at a low temperature of about 7 ° C. is raised to about 12 ° C., which is effective for preventing condensation on the surface of the cooling coil by passing through the dehumidifying coil 63 and the spray water heat exchanger 59b. Warm.

  That is, the hot water supplied to the heating coil 65 is not used when the temperature of the cold water supplied to the apparatus is raised. For this reason, if the hot water supplied at about 34 ° C. excludes the heat loss in the piping on the way, only the heat loss of the heating coil 65 may be reheated by the hot water producing means. Therefore, the heat source can be effectively used and the cost can be reduced.

  The cold water supplied to the cooling coil 68 is returned to predetermined cold water production means through the pipe 95. The temperature of the cold water return (H) at this time is set to about 17 ° C., for example. Therefore, the temperature difference from the supplied cold water (E) is as large as about 10 ° C. Thus, since the temperature difference between the inflow side and the outflow side of the cold water is large, the diameter of the pipe can be reduced and the cost of the equipment can be reduced.

  In the configuration of FIG. 1, the temperature of the air decreases along the traveling direction from the cooling coil 68 toward the dehumidifying coil 63. On the other hand, the temperature of the cold water rises along the traveling direction from the dehumidifying coil 63 to the cooling coil 68. As described above, in the configuration of FIG. 1, the energy required for cooling the processing air from the clean room is arranged according to the required temperature, and heat exchange is performed so that the chilled water can be used from the lowest temperature to the highest temperature in the order of the highest energy. Means are installed in series. The cold water at 7 ° C. passes through the dehumidifying coil, then passes through the spray water heat exchanger and finally the cooling coil. Accordingly, the cold water of 7 ° C. can be reused according to the high temperature → low temperature stage through which the processing air passes. The final return cold water temperature is 17 ° C. or higher, and a system for utilizing a large temperature difference in cold water can be established. This heat flow becomes a chilled water cascade system, and a large temperature difference can be secured, thereby saving energy.

  The cold recovery coil 64 provided in the air conditioning chamber 60 and the thermal recovery coil 67 provided in the air washer device 50 are connected by pipes 96 and 97 so that heat is transferred between the air washer device 50 and the air conditioning chamber 60. It is configured as follows. 98 is a pump and 99 is a valve.

  As shown in FIG. 1, in the present invention, as a heat exchanger, a dehumidifying coil 63, a spray water heat exchanger (third heat exchanger) 59b, and a cooling coil 68 are connected in series by piping. Yes. That is, the pipes between the heat exchangers are connected in a cascade manner. Therefore, compared with the case where a plurality of heat exchangers are installed in parallel, when installing the pipe, the dimension in the width direction of the pipe path can be narrowed, and the space can be saved.

  Moreover, since the removal rate of the organic substance contained in the processing air is improved, the apparatus can be made compact (reduction in cost). Furthermore, it is possible to save energy by reducing utility usage. Since the amount of makeup water supplied to the air washer device is variable, the amount of makeup water can be reduced.

  As described above, according to the present invention, it is possible to provide a pollutant removal apparatus that can effectively use a heat source and can suppress the growth of bacteria in a spray chamber.

It is a block diagram which shows the contaminant removal apparatus which concerns on embodiment of this invention. It is a block diagram which shows the contaminant removal apparatus which concerns on embodiment of this invention. It is explanatory drawing of a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 50 ... Air washer apparatus, 51a-54a ... Spray nozzle, 55 ... Supply circulation water tank, 56a, 56b ... Pump, 57a, 57b ... Water treatment filter, 58 ... Supply water drainage Heat exchanger, 59a ... makeup water heat exchanger, 59b ... spray water heat exchanger, 60 ... air conditioning chamber, 63 ... dehumidification coil, 64 ... cold recovery coil, 65 ... Heating coil, 66 ... HEPA filter, 67 ... heat recovery coil, 68 ... cooling coil, 69 ... eliminator, 71-74 ... collection pipe, 80-86, 90-97 ·Piping

Claims (3)

A spray chamber having a plurality of rows of spray nozzles, a circulating water tank connected to the spray chamber by a water collecting pipe, the spray nozzle and the circulating water tank are connected by a pipe, and the circulating water ejected from the spray nozzle A contaminant removing device that removes contaminants in the processing air flowing into the spray chamber and sends the air to the air conditioning chamber,
Make-up water flows into the first heat exchanger supplied with cold water through the second heat exchanger supplied with the waste water from the circulating water tank, and is supplied from the first heat exchanger to the spray nozzle. ,
The makeup water is directly supplied to the spray chamber without going through the circulating water tank and injected from any of the spray nozzles,
A cooling means for cooling the inflowing air with cold water is provided in the spray chamber,
The cold water cools components installed in the air conditioning chamber and then flows into a third heat exchanger, and is supplied from the third heat exchanger to the cooling means, and the makeup water and cold water are supplied. The pollutant removing device, wherein the first heat exchanger and the third heat exchanger are connected in series by a pipe . The cold water is supplied to a dehumidification coil of a part installed in the air-conditioning room, and the dehumidification coil is cooled and then sent to the cooling coil of the cooling means through the third heat exchanger to gradually increase the temperature of the cold water. The pollutant removing device according to claim 1, wherein the pollutant removing device is raised.   The pollutant removal device according to claim 1 or 2, wherein a heating coil to which hot water is supplied is provided in the air conditioning room.

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