JP5173463B2 - Clean air circulation system and clean air circulation method - Google Patents

Description

  The present invention relates to a clean air circulation system and a clean air circulation technique.

  As a dehumidifying device for producing air having a low dew point temperature (for example, −70 degrees or less), a dehumidifying device such as an adsorption rotor type, a PSA (Pressure Swing Adsorption) type using compressed air, or a membrane type is known. Among these dehumidifiers, as an apparatus for supplying dry room (registered trademark of the present applicant) and other low dew point chambers and clean dry air, an adsorption rotor type dehumidifier (for example, from the viewpoint of manufacturing cost) (See Patent Document 1).

Clean dry air (CDA) is more expensive than normal air or clean room air. Therefore, as a method for reducing the price, it is considered to circulate or reuse the CDA. As a technique for circulating CDA, a technique using a blower (see, for example, Patent Document 2) and a technique using a compressor are known. In addition, as another technique for circulating CDA, used high-clean air is sucked into the intake port of the ejector, and the used high-clean air is driven by replenishing high-clean dry air injected from the nozzle. A technique for circulation is known (for example, see Patent Document 3).
JP-A-11-188224 JP 2000-70657 A JP 2001-141272 A JP 2001-38137 A JP 2004-141721 A JP 2007-185617 A Japanese Patent No. 3364708

  As a technique for circulating clean dry air (CDA), a technique using a blower or a compressor or a technique using an ejector is known. However, in the technology using a blower or a compressor, there is a concern that the dew point temperature may increase or chemical contamination may occur. Further, when the CDA is circulated, it is assumed that the dew point temperature of the circulated CDA changes depending on the operating conditions of the CDA generator that supplies the CDA. For example, the dew point temperature of the circulating CDA, in other words, the dew point temperature of the return CDA discharged from the chamber, is determined by the object (for example, a semiconductor or a liquid crystal element) at the start of the operation of the CDA generator or inside the chamber to which the CDA is supplied. It is assumed that the height of the electronic component increases. When a circulating CDA having a high dew point temperature is used, there is a possibility that the dew point temperature inside the chamber cannot be maintained at an optimum value.

  In the present invention, in view of the above problems, the amount of clean air supplied from the clean air generator is reduced by circulating clean air, and the dew point temperature of the low dew point space to which the clean air is supplied is optimal. It is an object to provide a technology for realizing the system.

  In the present invention, in order to solve the above-described problems, the flow rate of the exhausted clean air discharged from the low dew point space is adjusted in accordance with the operation state of the clean air generation device and the usage state of the low dew point space.

  Specifically, the clean air circulation according to the present invention includes a clean air supply passage through which clean air sent from a clean air generating device that generates clean air, and the clean air is supplied via the clean air supply passage. Is maintained at a low dew point temperature, a circulation path through which exhausted clean air discharged from the low dew point chamber flows and merges with the clean air supply path, and the clean air supply path and the circulation path An attraction unit provided in a merging unit for inducing exhaust clean air flowing through the circulation passage by dynamic pressure when jetting clean air supplied from the clean air generating device toward the low dew point chamber; A first adjusting unit that adjusts the flow rate of the exhausted clean air flowing through the circulation passage according to attribute information relating to a factor that changes the dew point temperature of the air.

  According to the present invention, the exhausted clean air is attracted by the dynamic pressure at the time of jetting toward the low dew point chamber, thereby causing an increase in dew point temperature and chemical contamination that are a concern when using a blower or a compressor. And clean air can be circulated. As a result, the supply amount of clean air generated by the clean air generation device can be reduced. In addition, it is possible to optimize the dew point temperature in the low dew point room by adjusting the flow rate of the exhausted clean air flowing through the circulation passage according to the attribute information.

  The clean air circulation system of the present invention includes a clean air supply passage, a low dew point chamber, and a circulation passage. The clean air supplied from the clean air generator flows through the clean air supply passage. One end of the clean air supply passage can be connected to the clean air generator, and the other end of the clean air supply passage can be connected to the low dew point chamber. A clean air production | generation apparatus can be comprised by the dehumidification apparatus which manufactures the air of low dew point temperature. For example, an existing dehumidifying device such as a rotor type, a PSA method using compressed air, or a membrane type can be used as the clean air generation device.

  The clean room is supplied to the low dew point chamber so that the room is kept at a low dew point temperature, and the low dew point chamber can be used as a manufacturing place for manufacturing semiconductors and a storage place for storing manufactured parts and the like.

  Exhaust clean air discharged from the low dew point chamber flows through the circulation passage. One end of the circulation passage can be connected to the low dew point chamber, and the other end can be connected to the clean air supply passage. The circulation passage of the present invention circulates the exhaust clean air to low dew point chambers other than the low dew point chamber that exhausted exhaust clean air, as well as the passage that circulates exhaust clean air to the low dew point chamber itself that exhausted clean exhaust air. It is good also as a passage to make it go.

  The attracting part attracts exhausted clean air that flows through the circulation passage using dynamic pressure when jetting clean air toward the low dew point chamber. The jet of clean air can be realized by a nozzle. The attracting unit can be configured as an attracting unit, for example. Specifically, a chamber is provided at the junction, and a nozzle is installed inside the chamber. When clean air is ejected from the nozzle under a predetermined pressure, air around the nozzle is attracted, and the exhausted exhaust air that has been attracted flows into the low dew point chamber together with the ejected clean air. Thereby, circulation of exhaust clean air by attraction using dynamic pressure becomes possible.

  A 1st adjustment part adjusts the flow volume of the discharge | emission clean air which flows through a circulation path according to attribute information. The first adjustment unit can be configured by a damper. The damper may be a damper that can be opened and closed by a motor or the like (for example, a motor damper), or may be a damper that can be manually opened and closed (for example, a volume damper).

The attribute information is information relating to a factor that changes the dew point temperature of the exhaust clean air. More specifically, the attribute information includes at least one of operation information of the clean air generation device, opening / closing information of the entrance / exit of the low dew point chamber, and dew point temperature information in the low dew point chamber. Can be. The operation information of the clean air generation device is information indicating that the clean air generation device is activated. The opening / closing information of the entrance / exit of the low dew point chamber is information indicating that the entrance / exit of the low dew point chamber is opened / closed. The dew point temperature information in the low dew point room is information indicating the dew point temperature in the low dew point room. It is assumed that the dew point temperature in the low dew point room does not satisfy the reference value when the clean air generator is started. In addition, when opening / closing the entrance / exit of the low dew point chamber, it is expected that the dew point temperature in the low dew point chamber will rise due to the flow of external air from the entrance / exit. In this way, when the clean air generator is started up or when the low dew point chamber is opened and closed, the dew point temperature in the low dew point chamber may not meet the standard value.If the dew point temperature in the low dew point chamber is high, There is a concern that the dew point temperature of the exhausted clean air exhausted from it will also increase. Therefore, in the present invention, the flow rate of the exhaust clean air flowing through the circulation passage is adjusted based on each information such as when the clean air generating device is started, when the low dew point chamber is opened and closed, or when the dew point temperature is in the low dew point chamber. . Thus, according to the present invention, it is possible to circulate the exhaust clean air and optimize the dew point temperature in the low dew point space.

  The clean air circulation system of the present invention includes a clean air auxiliary passage through which the clean air flows to the attraction portion when the first adjusting portion restricts a flow rate of the exhaust clean air flowing through the circulation passage, A second adjustment unit that adjusts the flow rate of the exhausted clean air flowing through the circulation passage may be further provided in correspondence with the flow rate adjustment of the exhausted clean air by the adjusting unit.

  When the circulation of exhausted clean air is restricted, there is a concern that the clean air supplied to the low dew point space is insufficient. Therefore, in the present invention, when the clean air auxiliary passage and the second adjusting unit are provided and circulation of the exhaust clean air is restricted, the clean air sent from the clean air generating device is replaced with the exhaust clean air. It was decided to attract. Thus, by enabling switching of the air to be attracted by the attracting unit according to the attribute information, it is possible to circulate the exhausted clean air and optimize the dew point temperature in the low dew point space. In the present invention, the second adjustment unit is different from the first adjustment unit. For example, the first adjustment unit is provided at the junction of the clean air auxiliary passage and the circulation passage. You may make it give the function of said 2nd adjustment part.

  In the clean air circulation system of the present invention, each of the first adjustment unit and the second adjustment unit is a damper, and the clean air circulation system controls each damper based on the attribute information. The control unit further controls the dampers to limit the circulation of the exhausted clean air for a predetermined time after the startup of the clean air generation device, and the entrance and exit of the low dew point chamber When each of the dampers is opened and closed, the dampers are controlled to limit the circulation of the exhausted clean air for a predetermined time from the opening and closing. When the dew point temperature in the low dew point chamber exceeds the reference value, the circulation of the exhausted clean air is restricted. The dampers may be controlled as described above.

  In the present invention, the first adjustment unit and the second adjustment unit are configured by dampers, and by further providing a control unit for controlling the dampers, automation of the flow adjustment of the exhaust clean air attracted by the attraction unit is realized. Yes. In addition, by controlling the damper as described above, it is possible to reduce the amount of clean air supplied from the clean air generator accurately and efficiently, and to optimize the dew point temperature in the low dew point chamber. It becomes.

  Further, in the clean air circulation system of the present invention, the clean air supply passage is branched into a plurality of portions, the low dew point chamber is connected to each of the plurality of clean air supply passages branched, and the circulation passage is Connected to each of the low dew point chambers, the attraction portion is provided at a junction of the plurality of branched clean air supply passages and a circulation passage connected to the respective low dew point chambers, and the first adjustment The section may be provided in a circulation passage connected to each of the low dew point chambers.

According to the present invention, in each of the plurality of low dew point chambers, it is possible to reduce the supply amount of clean air supplied from the clean air generating device and optimize the dew point temperature in the low dew point chamber. Moreover, it becomes possible to aim at reduction of an installation cost by sharing the clean air production | generation apparatus which is an air source with respect to multi-system low dew point space. For example, if the entrances and exits of adjacent low dew point chambers are simultaneously opened and closed, the exhausted clean air that is exhausted cannot be circulated, and the supply amount of clean air supplied from the clean air generating device may increase. Therefore, when providing a plurality of low dew point chambers as in the present invention, it is preferable to open and close the doors of the low dew point chambers in order. Thereby, the phenomenon that the supply amount of the clean air supplied from the clean air generator increases at a time can be prevented. When the clean air circulation system is configured by a plurality of low dew point chambers as described above, it is preferable to arrange a plurality of configurations such as the above-described clean air auxiliary passage and second adjustment unit.

  Further, the clean air circulation system of the present invention is connected to the discharge passage through which the exhaust clean air discharged from the low dew point chamber flows and discharges the exhaust clean air to the outside of the low dew point chamber, It is good also as a structure further provided with the exhaust clean air utilization chamber which can utilize this exhaust clean air by supplying the exhaust clean air which flows through this exhaust passage.

  According to the present invention, the exhaust passage can discharge exhaust clean air to the outside of the low dew point chamber. Further, by connecting the exhaust clean air utilization chamber to the exhaust passage, the exhaust clean air flowing through the exhaust passage can be used. In addition, it is preferable to provide a switching unit or the like in the discharge passage so that supply of exhaust clean air to the exhaust clean air utilization chamber can be switched. For example, the low dew point chamber can be used as a clean stocker for predetermined equipment, and the exhaust clean air use room can be used as a low dew point booth for maintenance of predetermined equipment. A low dew point chamber may be further provided. For example, in the case where a low dew point chamber is further provided, when the low dew point chamber is used for an application in which clean air in the room may be deteriorated, such as an operation in which a solvent is generated, the exhaust cleaning is performed. It is preferable to exhaust all the air without circulating the air.

  Further, the clean air circulation system of the present invention includes a second clean air supply passage branched from the clean air supply passage, and a second low dew point chamber in which the clean air is supplied via the second clean air supply passage. And a second discharge passage through which exhausted clean air discharged from the second low dew point chamber flows, wherein the dew point temperature in the room is higher than the low dew point chamber and the second dew point chamber. It is good also as a structure further provided with the 2nd discharge passage which guides | emits the exhaust clean air discharged | emitted from a 2nd low dew point chamber.

  According to the present invention, it is possible to effectively use exhausted clean air discharged from the second low dew point chamber. When there are a plurality of low dew point chambers, the required dew point temperature in the low dew point chamber differs depending on the application of the low dew point chamber. Therefore, in the present invention, the exhausted clean air discharged from the second dew point chamber is guided to the third dew point chamber whose indoor dew point temperature is higher than that of the second dew point chamber.

  Further, in the clean air circulation system of the present invention, the low dew point chamber has a clean area where the clean air in the room is not contaminated and a contaminated area where the clean air in the room is contaminated, and is discharged from the clean area. The exhausted clean air may be circulated to the low dew point chamber through the circulation passage, and the exhausted clean air exhausted from the contaminated area may be exhausted to the outside of the clean air circulation system.

  The present invention assumes that one low dew point space is used for multiple purposes. It is possible to operate the clean air circulation system more efficiently by discharging the exhaust clean air discharged from the contaminated area outside the clean air circulation system and circulating only the exhaust clean air discharged from the clean area. Become.

As mentioned above, although the clean air circulation system of this invention was demonstrated, this invention can be set as the clean air circulation method which has a function and an effect equivalent to the clean air circulation system mentioned above. Specifically, the present invention provides a clean air supply passage through which clean air sent from a clean air generating device that generates clean air, the clean air is supplied via the clean air supply passage, and a room has a low dew point. A clean device comprising: a low dew point chamber maintained at a temperature; and a circulation passage through which exhausted clean air discharged from the low dew point chamber or a low dew point chamber adjacent to the low dew point chamber flows and merges with the clean air supply passage A clean air circulation method for circulating clean air in an air circulation system, wherein the clean air supplied from the clean air generating device is directed to the low dew point chamber at a junction of the clean air supply passage and the circulation passage. In response to attribute information relating to factors that cause the exhausted clean air flowing through the circulation passage to be drawn into the clean air supply passage by the dynamic pressure at the time of jetting and changes the dew point temperature of the exhausted clean air A clean air circulation method for adjusting the flow rate of the exhaust clean air flowing through the circulation passage.

  According to the present invention, the clean air is circulated to reduce the supply amount of the clean air supplied from the clean air generation device, and to optimize the dew point temperature of the low dew point chamber to which the clean air is supplied. Can be provided.

  Next, an embodiment of the clean air circulation system of the present invention will be described based on the drawings. In the embodiment described below, a CDA circulation system that circulates ultra-low-humidity air (hereinafter referred to as CDA or clean dry air) having a dew point temperature of −70 degrees or less will be described as an example.

(First embodiment)
<Configuration>
FIG. 1 shows the configuration of the CDA circulation system of the first embodiment. As shown in the figure, the CDA circulation system of this embodiment includes a CDA supply duct 11, an air supply chamber 2, an induction unit 3, a low dew point chamber 4, a circulation duct 13, a discharge duct 12, and an auxiliary duct 14. The control unit 7 and motor dampers 51, 52, and 53 are configured. Details will be described below.

  The CDA supplied from the CDA generator 1 flows through the CDA supply duct 11 (corresponding to the clean air supply passage of the present invention). The CDA supply duct 11 has one end connected to the CDA generator 1 and the other end connected to the air supply chamber 2. Note that existing ducts can be used for the respective ducts such as the CDA supply duct 11 and the circulation duct 13. A cross-sectional shape, a material, etc. are not specifically limited.

  The CDA generator 1 (corresponding to the clean air generator of the present invention) generates ultra-low humidity air having a dew point temperature of −70 degrees or less. The CDA generated by the CDA generator 1 is air from which gas impurities (molecular contaminants) have been removed. Dust is removed by a filtration filter provided inside or outside the CDA generator 1. As a filtration filter, a HEPA filter (High Efficiency Particulate Air Filter) is illustrated and can be attached to the ceiling of the low dew point chamber 4, for example. The CDA generator 1 can be configured by an existing clean air generator. For example, the CDA generator 1 may be a rotor-type clean air generator that reduces the humidity in the process air by passing the process air through a rotatable rotor having silica gel or metal silicate ( (For example, refer to JP 2001-38137 A and JP 2004-141721 A). The CDA generator 1 may be a pressure swing type clean air generator that performs gas purification, heating regeneration, and cooling processes while switching between a plurality of adsorption towers and continuously supplies purified gas. (For example, refer to JP 2007-185617 A.). In addition, what is necessary is just to adjust the pressure of CDA suitably as needed, when using a pressure swing type clean air production | generation apparatus.

  In the air supply chamber 2, CDA used when ejected by the nozzle 32 stays. A CDA supply duct 11 is connected to one side surface of the air supply chamber 2, and the CDA flows into the air supply chamber 2 through the CDA supply duct 11. In addition, one end of the auxiliary duct 14 is connected to the side surface on the air supply chamber 2 that is located on the extension line of the CDA supply duct 11 and that faces the side surface to which the CDA supply duct 11 is connected. Further, on the side surface of the air supply chamber 2 adjacent to both the side surface to which the CDA supply duct 11 is connected and the side surface to which the auxiliary duct 14 is connected, the suction port of the nozzle 32 is supplied with air. It is provided so as to protrude into the chamber 2. The axial direction of the CDA supply duct 11 and the axial direction of the nozzle 32 are substantially orthogonal. Details of the auxiliary duct 14 and the nozzle 32 will be described later.

  The attraction unit 3 (corresponding to the attraction portion of the present invention) is adjacent to the air supply chamber 2 and is constituted by an attraction chamber 31 and a nozzle 32. The supply chamber 2 and the induction chamber 31 communicate with each other via a nozzle 32, and the CDA sucked from the intake port of the nozzle 32 located in the supply chamber 2 is a nozzle 32 located in the induction chamber 31. Are ejected into the attraction chamber 31 from the nozzle outlet. An air supply port 41 is provided on the side surface of the induction chamber 31 in the blowing direction of the nozzle 32, and through the air supply port 41, the induction chamber 31 and the low dew point chamber 4, more specifically, the induction chamber 31 The low dew point chamber 4 communicates with the ceiling chamber 48a. As a result, CDA ejected from the nozzle 32 flows into the low dew point chamber 4. Further, air flowing through the circulation duct 13 (return CDA at the time of circulation control; CDA at the time of circulation restriction control; CDA at the time of circulation restriction control. A suction port 33 for taking in control will be described later. Thereby, the air flowing through the circulation duct 13 is attracted by the dynamic pressure of the CDA ejected from the nozzle 32. In the present embodiment, the supply air pressure at the nozzle 32 is set to about 500 Pa. The arrows in the attracting unit 3 in FIG. 1 indicate the air flow.

  The interior of the low dew point chamber 4 is filled with CDA, and can be used as a manufacturing place for semiconductors, lithium ion batteries, organic EL, crystal resonators, a storage place (stocker) for these electronic components and electronic devices, and the like. The low dew point chamber 4 is a sealed space so that the internal dew point temperature is kept constant. An air supply port 41 is provided in the upper part of the low dew point chamber 4, and the air returned from the low dew point chamber 4 by the attracting action through the CDA ejected from the nozzle 32 and the circulation duct 13 is low through the air supply port 41. The dew point chamber 4 is supplied. In addition, a first exhaust port 42 and a second exhaust port 43 are provided in an underfloor chamber 48b provided in the lower part of the low dew point chamber 4, and CDA that has passed through the low dew point chamber 4 can be discharged to the outside. An entrance / exit 44 is provided on a side surface of the low dew point chamber 4 so that an operator can enter and exit and electronic components can be carried in. The CDA ejected from the nozzle 32 at a pressure of about 500 Pa sequentially passes through the ceiling chamber 48a, the ceiling 45, the space 49 for production and storage of electronic components, the floor 46, and the underfloor chamber 48b to be discharged first. It flows to the outlet 42 or the second outlet 43. The ceiling 45 and the floor 46 are both made of punched steel plates, and are devised so that the CDA passing through the low dew point chamber 4 becomes more laminar.

  One end of the discharge duct 12 (corresponding to the discharge passage of the present invention) is connected to the first exhaust port 42, and the discharge CDA discharged from the first exhaust port 42 flows. Note that the other end of the discharge duct 12 may be opened outside the CDA circulation system 1 or connected to another low dew point chamber. The discharge duct 12 is provided with a first motor damper 51, and the flow rate of the discharge CDA flowing through the discharge duct 12 can be adjusted.

The circulation duct 13 (corresponding to the circulation passage of the present invention) has one end connected to the second exhaust port 43 and the other end connected to the suction port 33 of the induction chamber 31 and is discharged from the second exhaust port 43. Return CDA flows inside. The return CDA is also a CDA discharged from the low dew point chamber 4, but the CDA to be circulated is referred to as a return CDA in order to distinguish it from the discharge CDA discharged from the first exhaust port 42. A second motor damper 52 is provided on the upstream side of the circulation duct 13 (near the second discharge port), and the flow rate of the return CDA flowing through the circulation duct 13 can be adjusted. In other words, the attraction of the return CDA in the attraction unit 3 can be limited by the second motor damper 52.

  The auxiliary duct 14 (corresponding to the clean air auxiliary passage of the present invention) has one end connected to the air supply chamber 2 and the other end connected to the circulation duct 13. In the auxiliary duct 14, the CDA generated by the CDA generator 1 flows in parallel with the nozzle 32. A third motor damper 53 is provided on the upstream side of the auxiliary duct 14 (near the connection portion with the air supply chamber 2), and the flow rate of CDA flowing through the auxiliary duct 14 can be adjusted. The auxiliary duct 14 is used as an auxiliary to supplement the supply amount of CDA to the low dew point chamber 4 when the circulation of the return CDA flowing through the circulation duct 13 is restricted.

  The first motor damper 51, the second motor damper 52 (corresponding to the first adjusting portion of the present invention), and the third motor damper 53 (corresponding to the second adjusting portion of the present invention) flow through the duct in which each is installed. Adjust the flow rate of CDA and return CDA. In the present embodiment, these motor dampers are electrically connected to the control unit 7, and the opening / closing operation and the opening degree adjustment are controlled by the control unit 7.

  The control unit 7 (corresponding to the control unit of the present invention) controls each motor damper based on attribute information such as operation information, open / close information, and dew point temperature information. The control unit 7 can be configured by a computer including a central processing unit (CPU), a memory, and the like. In the control unit 7, an internal computer acquires operation information and the like as an electrical signal, and controls each motor damper according to a predetermined process stored in a memory. The operation information is information indicating that the CDA generation device 1 has been started, the opening / closing information is information indicating that the entrance / exit 44 of the low dew point chamber 4 has been opened and closed, and the dew point temperature information is the low dew point. It is information indicating the dew point temperature in the chamber 4. The operation information can be acquired by electrically connecting the switch of the CDA generation device 1 and the control unit 7, for example. The opening / closing information can be acquired by providing an opening / closing sensor near the entrance / exit 44. The dew point temperature information can be acquired by providing a dew point temperature sensor inside the low dew point chamber 4. Thus, by electrically connecting each sensor and the control unit 7, opening / closing information and dew point temperature information can be acquired.

<Driving method>
Next, the operation method of the CDA circulation system 100 described above will be described together with the control of each motor damper by the control unit 7.

  FIG. 2 shows an operation control flow of the CDA circulation system. In step S01, attribute information such as operation information, open / close information, and dew point temperature information is input to the computer. That is, information acquired through various sensors is input to an electrically connected computer. When the input of attribute information is completed, the process proceeds to step S02.

In step S02, the motor dampers 51, 52, 53 are controlled by the computer based on the acquired information. Specifically, when it is determined that the CDA generation device 1 is activated based on the input operation information, the opening degree of the first motor damper 51 is 100%, the opening degree of the second motor damper 52 is 0%, Each motor damper is controlled by a computer so that the opening degree of the motor damper 53 is 100% (hereinafter also referred to as circulation regulation control). When the CDA generator 1 is activated, it is assumed that the dew point temperature in the low dew point chamber 4 does not satisfy the reference value. Under such circumstances, when the return CDA discharged from the low dew point chamber 4 is circulated, There is a concern that the dew point temperature in the low dew point chamber 4 cannot be optimized. Therefore, when the CDA generator 1 is started, the second motor damper 52 is fully closed, the attraction of the return CDA is restricted, and the CDA discharged from the low dew point chamber 4 is discharged to the outside through the discharge duct 12 as the discharged CDA. It was. If the circulation of the return CDA is restricted, there is a possibility that the supply amount of CDA to the low dew point chamber 4 cannot be secured sufficiently. Therefore, the third motor damper 53 is fully opened, CDA is caused to flow through the auxiliary duct 14, and the air that is attracted by the nozzle 32 is defined as CDA. This makes it possible to optimize the dew point temperature in the low dew point chamber 4 even when the CDA generator 1 is started.

  Further, when the entrance / exit 44 is opened and closed, external air flows from the entrance / exit 44 and the dew point temperature in the low dew point chamber 4 is expected to rise. Under such circumstances, the air is discharged from the low dew point chamber 4. If the return CDA is circulated, the dew point temperature in the low dew point chamber 4 cannot be optimized. Further, it is not preferable to circulate the return CDA discharged from the low dew point chamber 4 even when the dew point temperature in the low dew point chamber 4 is actually measured and the dew point temperature does not satisfy the reference value. Therefore, when it is determined that the entrance / exit 44 of the low dew point chamber 4 is opened / closed based on the open / close information, or when it is determined that the dew point temperature in the low dew point chamber 4 does not satisfy the reference value based on the dew point temperature information. In addition, the same control as described above is executed. As a result, the dew point temperature in the low dew point chamber 4 can always be kept optimal. The reference value in the low dew point chamber 4 can be set in advance according to the purpose of use of the low dew point chamber 4.

  On the other hand, the CDA circulation system 100 according to the first embodiment is characterized by reducing the supply amount of the CDA generated by the CDA generator 1 by circulating the return CDA discharged from the low dew point chamber 4. Therefore, in cases other than the above, that is, when the CDA generator 1 is started, when the inlet / outlet 44 is opened or closed, or when the dew point temperature in the low dew point chamber 4 does not satisfy the reference value, the first motor damper 51 is opened. Each motor damper is controlled by a computer so that the degree is 20%, the opening degree of the second motor damper is 100%, and the opening degree of the third motor damper is 0% (hereinafter also referred to as circulation control). As a result, the return CDA discharged from the low dew point chamber 4 flows through the circulation duct 13, and the return CDA flowing through the circulation duct 13 is attracted by the dynamic pressure of the nozzle 32, whereby the return CDA circulates. Thereby, it becomes possible to reduce the supply amount of CDA supplied from the CDA generation apparatus 1. The reason why the opening degree of the first motor damper 51 is set to 20% is as follows. That is, it is assumed that the ratio of the induced air volume and the supply air volume in the induction unit 3 is 4: 1, and the diameter of the circulation duct 13 is 1/4 of the diameter of the CDA supply duct 11 to the supply chamber 2. Is. The ratio between the amount of induced air and the amount of supplied air varies depending on the design of the shape and the diameter of the nozzle 32.

  For example, the switching between the circulation control and the circulation regulation control may be performed as follows. When the circulation restriction control is executed based on the dew point temperature in the low dew point chamber 4, the circulation restriction control may be shifted to the circulation control when the dew point temperature in the low dew point chamber 4 satisfies the reference value. On the other hand, when the circulation restriction control is executed based on the operation information or the opening / closing information, for example, after a predetermined time has elapsed, the circulation restriction control may be shifted to the circulation control. For the predetermined time, the dew point temperature change in the low dew point chamber 4 at the start of the CDA generator 1 and the dew point temperature change in the low dew point chamber 4 due to opening / closing of the entrance / exit 44 are obtained in advance by experiments, etc. Can be set.

  The switching between the circulation control and the circulation regulation control may be proportional control. The proportional control is to proportionally control the opening degree of the first motor damper 51, the second motor damper 52, and the third motor damper 53. That is, in the control based on the dew point temperature, according to the dew point temperature, the opening degree of the first motor damper 51 is set for a predetermined time from the start or the open / close in the control based on the opening / closing of the entrance / exit 44 according to the start of the CDA generator 1. Close gradually from full opening. On the other hand, the second damper 52 is gradually opened from the fully closed state, and the third damper is gradually closed from the fully opened state. As described above, the switching between the circulation control and the circulation regulation control is set to the proportional control, so that the switching can be executed more smoothly, and the supply amount of the CDA supplied to the low dew point chamber 4 can always be kept constant. it can. Further, the CDA passing through the low dew point chamber 4 can always be laminar.

<Effect>
According to the CDA circulation system 100 of the first embodiment described above, the circulation duct 13 is formed by the dynamic pressure at the time of ejection of the nozzle 32 that ejects CDA toward the low dew point chamber 4 (in this embodiment, about 500 Pa). The flowing back CDA can be attracted to circulate the returning CDA. As a result, it is possible to circulate the return CDA without causing an increase in dew point temperature or chemical contamination, which is a concern when using a blower or a compressor. Thereby, the supply amount of CDA supplied from the CDA generation apparatus 1 can be reduced. In addition, the dew point temperature in the low dew point chamber 4 can be optimized by switching between the circulation regulation control and the circulation control according to the attribute information. In the present embodiment, the dew point temperature in the low dew point chamber 4 can be optimized by supplying about 20% of the circulating CDA. In other words, it is possible to reduce the supply amount of CDA to 20% of the conventional amount with one CDA circulation system.

(Second embodiment)
FIG. 3 shows the configuration of the CDA circulation system of the second embodiment. The CDA circulation system 101 of the second embodiment includes a second low dew point chamber 4 a in addition to the low dew point chamber 4, and the return CDA discharged from the second low dew point chamber 4 a circulates in the low dew point chamber 4. Is done. In other words, in the CDA circulation system 101 of the second embodiment, the return CDA discharged from the second low dew point chamber 4 adjacent to the low dew point chamber 4 is supplied to the low dew point chamber 4 in a cascade manner. In addition, about the same structure, the detailed description is abbreviate | omitted by attaching | subjecting a common number. Further, the Roman letter attached to the end of the reference numeral is given according to the embodiment, and the configuration given the common number has the same function, and the detailed description thereof is omitted. The same applies to other embodiments described below.

  A CDA supply duct 11a is connected to the second low dew point chamber 4a, and CDA generated by a CDA generator not shown is supplied. The basic configuration of the second low dew point chamber 4a is the same as that of the low dew point chamber 4, and the second low dew point chamber 4a can also be used as a semiconductor manufacturing place or storage place. Moreover, the discharge duct 12a is connected to the 2nd low dew point chamber 4a, and discharge | emission of discharge CDA discharged | emitted from the 2nd low dew point chamber 4a is possible. A circulation duct 13 a is connected to the second low dew point chamber 4 a so that the return CDA discharged from the second low dew point chamber 4 a can be supplied to the low dew point chamber 4. Each of the CDA supply duct 11a, the discharge duct 12a, and the circulation duct 13a is provided with a volume damper 63a, a volume damper 61a, and a volume damper 62, and the flow rate of CDA flowing through each duct can be adjusted.

  An attraction unit 3 and a discharge duct 12 are connected to the low dew point chamber 4. In addition, an air supply chamber 2 is connected to the attraction unit 3, and a CDA supply duct 11 is connected to the air supply chamber 2. In the second embodiment, the attracting unit 3 includes the attracting chamber 31 and the nozzle 32, and basically has the same configuration as the attracting unit 3 of the first embodiment. However, the second embodiment is different from the first embodiment in that a circulation duct 13a through which the return CDA discharged from the second low dew point chamber 4a flows is connected to the suction port 33 of the attracting unit 3. As a result, in the CDA circulation system 101 of the second embodiment, the return CDA discharged from the second low dew point chamber 4a is attracted by the attraction unit 3. The CDA supply duct 11 and the discharge duct 12 are provided with a volume damper 63 and a volume damper 61, respectively, so that the flow rate of CDA flowing through each duct can be adjusted.

In the CDA circulation system 101 of the second embodiment, each damper is not a motor damper but a volume damper. Therefore, the flow rate of CDA flowing through each duct can be adjusted manually. The flow rate adjustment method may be performed according to the circulation control and the circulation regulation control in the first embodiment. That is, when the CDA generator is started, when the opening / closing port 44a of the second low dew point chamber 4a is opened and closed, and the dew point temperature of the second low dew point chamber 4a does not satisfy the reference value, the opening degree of the volume damper 63a is 100. %, The opening of the volume damper 61a is 100%, the opening of the volume damper 62 is 0%, the opening of the volume damper 63 is 100%, and the opening of the volume damper 61 is 100%. adjust. In cases other than the above, that is, when the return CDA discharged from the second low dew point chamber 4a is supplied to the low dew point chamber 4 in a cascade manner, the opening degree of the volume damper 63a is 100% and the volume damper 61a Each volume damper is adjusted so that the opening degree is 20%, the opening degree of the volume damper 62 is 100%, the opening degree of the volume damper 63 is 20%, and the opening degree of the volume damper 61 is 100%.

  According to the CDA circulation system 101 of the second embodiment, the return CDA discharged from the second low dew point chamber 4a can be effectively used in the low dew point chamber 4, and the CDA supply amount from the CDA generator is reduced. Can do. Further, by adjusting the opening degree of each volume damper according to the attribute information, the dew point temperature in the low dew point chamber 4 and the second low dew point chamber 4a can be optimized. Note that each volume damper installed in the second embodiment may be a motor damper, a control unit may be provided, and each motor damper may be controlled by a computer in the control unit.

(Third embodiment)
FIG. 4 shows the configuration of the CDA circulation system of the third embodiment. The CDA circulation system 102 of the third embodiment is provided with ten low dew point chambers 4 described in the first embodiment, and returns to each of the low dew point chambers 4 and is configured to circulate the CDA (CDA supply duct 11, supply A gas chamber 2, an induction unit 3, a circulation duct 13, a discharge duct 12, an auxiliary duct 14, and a motor damper) are provided. The low dew point chamber 4 in the present embodiment can be used as a stocker particularly in a robotized transfer process. A total of 10 low dew point chambers 4 are provided on both sides with the conveyance space 99 in between. In this embodiment (FIG. 3) and a fifth embodiment (FIG. 6) to be described later, the low dew point chambers 4 are drawn side by side in the vertical direction, but a plurality of low dew point chambers are arranged in the height direction. Alternatively, for example, they may be arranged in parallel in the horizontal direction on the same floor.

  Although not shown in the drawing, each motor damper can be executed by a computer in the control unit by electrically connecting the control unit to each motor damper. Therefore, the operation method of the CDA circulation system 101 of the third embodiment can be performed in the same manner as the CDA circulation system 100 of the first embodiment. That is, the attribute information may be input to the computer and the circulation control / circulation restriction control may be executed based on the attribute information.

  Here, when there are a plurality of circulation paths as in the CDA circulation system 102 of the third embodiment, for example, when a plurality of entrances and exits of each low dew point chamber are simultaneously opened and closed, the supply amount of CDA supplied from the CDA generator 1 May increase rapidly. Therefore, when there are a plurality of circulation paths as in the third embodiment, it is preferable to sequentially open and close the entrance / exit of each low dew point chamber. For example, a display may be provided in the vicinity of each doorway to display the opening / closing status of other doorways. Further, the computer of the control unit may be controlled to restrict the opening and closing itself so that a plurality of doors are not opened simultaneously. As a result, it is possible to suppress a rapid increase in the supply amount of CDA supplied from the CDA generation apparatus 1.

(Fourth embodiment)
FIG. 5 shows the configuration of the CDA circulation system of the fourth embodiment. The CDA circulation system 103 according to the fourth embodiment includes a low dew point booth 4c for maintenance and a third low dew point chamber 4d in addition to the configuration of the CDA circulation system 100 according to the first embodiment. The low dew point booth 4c for maintenance can be used for maintenance of an apparatus that not only dislikes contamination of the apparatus due to dust, but also disposes of moisture, such as a vacuum chamber. The low dew point booth 4c for maintenance is connected to the branch discharge duct 12c branched from the discharge duct 12, and the volume valve 61
, 61c is opened, and the return CDA discharged from the low dew point chamber 4 is supplied. The return CDA discharged from the low dew point chamber 4 flows through the discharge duct 12 and the circulation duct 13, but in this embodiment, the return CDA flowing through the discharge duct 12 can be used more effectively.

  The third low dew point chamber 4d is a low dew point chamber that can be used for applications where there is a possibility of deteriorating CDA, for example, in a process where solvent is generated. Therefore, in the third low dew point chamber 4d, the exhausted CDA is all discharged outside without being circulated. Thus, a more efficient CDA circulation system can be provided by appropriately arranging a circulation duct, an attracting unit, and the like according to the use of the low dew point chamber.

(Fifth embodiment)
FIG. 6 shows the configuration of the CDA circulation system of the fifth embodiment. The CDA circulation system 104 of the fifth embodiment has five low dew point chambers (first low dew point chamber 4e to fifth low dew point chamber 4i). The first low dew point chamber 4e to the third low dew point chamber 4g are low dew point chambers having a high clean level, and the fourth low dew point chamber 4h and the fifth low dew point chamber 4i are third low dew point chambers from the first low dew point chamber 4e. It is a low dew point chamber with a lower clean level than the dew point chamber 4g. The first low dew point chamber 4e is provided with a configuration necessary for circulating the discharged return CDA such as the circulation duct 13e and the attraction unit 3e to the discharged low dew point chamber. The first low dew point chamber 4e is provided with a configuration corresponding to the low dew point chamber 4 of the first embodiment.

  The second low dew point chamber 4f is provided with a circulation duct 13f for circulating the return CDA discharged from the second low dew point chamber 4f to the fourth low dew point chamber 4h. Cascade supply to the fourth low dew point chamber 4h having a lower clean level than the low dew point chamber 4f is possible. The third low dew point chamber 4g basically has the same configuration as the second low dew point chamber 4f, and circulates the return CDA discharged from the third low dew point chamber 4g to the fifth low dew point chamber 4i. A circulation duct 13g is provided. Thereby, it is possible to supply the return CDA discharged from the third low dew point chamber 4g in a cascade manner to the fifth low dew point chamber 4i having a clean level lower than that of the third low dew point chamber 4g. The fourth low dew point chamber 4h and the fifth low dew point chamber 4i are respectively connected to attracting units 3h and 3i to attract the return CDA discharged from the second low dew point chamber 4f or the third low dew point chamber 4g. , Can be supplied to each room.

  Thus, according to the CDA circulation system 104 of the fifth embodiment, a more efficient CDA circulation system is provided by appropriately arranging a circulation duct, an attracting unit, etc. according to the clean level of each low dew point chamber. can do. The term “clean” in the above description refers to a level at which contaminants at the gas / molecular level are adsorbed and removed instead of particulate dust. Then, the CDA discharged from the low dew point chamber having a high clean level from which contaminants at the gas / molecular level have been sufficiently removed can be returned to the low dew point chamber having a low clean level as returned CDA. The same configuration can be adopted when there are a plurality of low dew point chambers with different indoor humidity. That is, in a low dew point chamber that should be managed with low humidity, CDA discharged from other low dew point chambers is not introduced, and low humidity that allows higher humidity compared to a low dew point chamber that should be managed with low humidity is acceptable. In the dew point chamber, CDA from other low dew point chambers may be introduced.

(Sixth embodiment)
FIG. 7 shows the configuration of the CDA circulation system of the sixth embodiment. The CDA circulation system 105 of the sixth embodiment is based on the CDA circulation system 100 of the first embodiment, and the low dew point chamber 4j is divided into four regions. Specifically, in the CDA circulation system 105 of the sixth embodiment, the low dew point chamber 4j has a contaminated area 471 that may contaminate CDA and a clean area 472 that is less likely to contaminate CDA. A discharge duct 12 j for discharging the returned CDA to be discharged to the outside of the CDA circulation system 105 is connected to the contaminated area 471. on the other hand,
A circulation duct 13j that returns to the attraction unit 3j and guides the CDA is connected to the clean zone 472. Note that the contaminated area 471 is an area in which the CDA discharged may be contaminated by performing an operation of contaminating the indoor CDA, for example, in a work process using a solvent. On the other hand, the clean area 472 is an area where the discharged CDA is not contaminated because an operation process that does not use a solvent or the like is performed. Therefore, the CDA circulation system according to the present embodiment can be suitably used in a facility where the properties of CDA discharged by the process are different.

  According to the CDA circulation system 105 of the sixth embodiment, one low dew point chamber can be used for a plurality of applications. Then, it is possible to minimize the supply amount of CDA supplied from the CDA generation device and to optimize the dew point temperature in each divided area.

  Although the preferred embodiments of the present invention have been described above, the CDA circulation system of the present invention is not limited to these, and can include combinations of these as much as possible.

The structure of the CDA circulation system of 1st embodiment is shown. The operation control flow of a CDA circulation system is shown. The structure of the CDA circulation system of 2nd embodiment is shown. The structure of the CDA circulation system of 3rd embodiment is shown. The structure of the CDA circulation system of 4th embodiment is shown. The structure of the CDA circulation system of 5th embodiment is shown. The structure of the CDA circulation system of 6th embodiment is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... CDA production | generation apparatus 2 ... Air supply chamber 3 ... Attraction unit 4 ... Low dew point chamber 7 ... Control unit 12 ... Exhaust duct 13 ... Circulation duct 14 ... Auxiliary Duct 31 ... Attraction chamber 32 ... Nozzle 33 ... Suction port 41 ... Air supply port 42 ... First exhaust port 43 ... Second exhaust port 44 ... Exit port 45 ... Ceiling 46 ... Floor 51 ... First motor damper 52 ... Second motor damper 53 ... Third motor damper 100 ... CDA circulation system

Claims (10)

A clean air supply passage through which clean air sent from a clean air generating device that generates clean air flows;
A low dew point chamber in which the clean air is supplied through the clean air supply passage and the room is kept at a low dew point temperature;
The exhaust clean air discharged from the low dew point chamber flows, and on the downstream side of the clean air generator, a circulation passage that joins the clean air supply passage,
Discharge cleaning that is provided at the junction of the clean air supply passage and the circulation passage and flows through the circulation passage by dynamic pressure when the clean air supplied from the clean air generation device is jetted toward the low dew point chamber An attracting part that attracts air,
A first adjustment unit for adjusting the flow rate of the exhausted clean air flowing through the circulation passage;
With a clean air circulation system. 2. The clean air circulation system according to claim 1, further comprising a clean air auxiliary passage through which the clean air flows to the attraction unit when the first adjustment unit restricts a flow rate of the exhaust clean air flowing through the circulation passage. In the first adjustment unit, the flow rate of exhaust clean air flowing through the circulation passage is adjusted according to attribute information relating to a factor that changes the dew point temperature of the exhaust clean air,
The attribute information includes operation information of the clean air generation device, opening / closing information of the entrance / exit of the low dew point chamber, dew point temperature information in the low dew point chamber, and a certain time after the clean air generation device is activated. The clean air circulation system according to claim 1 or 2 , wherein at least one of information on whether or not there is included is included. A clean air auxiliary passage through which the clean air flows to the attraction portion when the first adjusting portion restricts a flow rate of the exhaust clean air flowing through the circulation passage;
A second adjusting unit that adjusts the flow rate of the exhausted clean air flowing through the circulation passage in response to the flow rate adjustment of the exhausted clean air by the first adjusting unit;
Each of the first adjustment unit and the second adjustment unit is a damper,
The clean air circulation system further includes a control unit that controls each damper based on the attribute information,
The controller is
When the clean air generating device is activated, the dampers are controlled to limit the circulation of the exhausted clean air for a predetermined time from the activation,
When opening and closing the entrance and exit of the low dew point chamber, the dampers are controlled to limit the circulation of exhausted clean air for a predetermined time from the opening and closing,
The clean air circulation system according to claim 1 or 3 , wherein when the dew point temperature in the low dew point chamber exceeds a reference value, each of the dampers is controlled so as to limit the circulation of exhaust clean air. The clean air supply passage is branched into a plurality of branches,
The low dew point chamber is connected to each of the plurality of clean air supply passages branched into the plurality,
The circulation passages are connected to the respective low dew point chambers;
The attraction part is provided at a junction of the plurality of clean air supply passages branched into the circulation passages connected to the respective low dew point chambers,
The clean air circulation system according to any one of claims 1 to 4, wherein the first adjustment unit is provided in a circulation passage connected to the respective low dew point chambers. A discharge passage through which exhausted clean air discharged from the low dew point chamber flows, and discharges the exhausted clean air to the outside of the low dew point chamber;
Which is connected with the discharge passage, by discharging clean air flowing through said discharge passage is supplied, any one of the the outlet available exhaust clean air utilization chamber clean air, from claim 1, further comprising a 5 Clean air circulation system as described in. A second clean air supply passage branched from the clean air supply passage;
A second low dew point chamber to which the clean air is supplied via the second clean air supply passage;
A second exhaust passage through which exhausted clean air exhausted from the second low dew point chamber flows, wherein the second dew point chamber has a higher dew point temperature than the second dew point chamber and the second dew point chamber; The clean air circulation system according to any one of claims 1 to 6 , further comprising a second exhaust passage that guides exhaust clean air exhausted from the low dew point chamber. The low dew point chamber has a clean area where indoor clean air is not contaminated and a contaminated area where indoor clean air is contaminated,
Exhaust clean air discharged from the clean area is circulated to the low dew point chamber through the circulation passage,
The clean air circulation system according to any one of claims 1 to 7 , wherein the exhaust clean air exhausted from the contaminated area is exhausted to the outside of the clean air circulation system. A clean air supply passage through which clean air sent from a clean air generating device for generating clean air flows, and a low dew point chamber in which the clean air is supplied through the clean air supply passage and the room is kept at a low dew point temperature; the exhaust clean air flow is discharged from the low dew point chamber adjacent to the low dew point room or the low dew point chamber, downstream of the clean air generating device, and a circulating passage which joins with the clean air supply passage A clean air circulation method for circulating clean air in a clean air circulation system,
The merging portion with the circulation passage and the clean air supply passage, a discharge clean air flowing through the circulation passage by the dynamic pressure at the time of ejecting the clean air supplied from the clean air generating device toward the low dew point chamber Attract ,
Adjusting the flow rate of the exhaust clean air flowing through the circulation passage,
Clean air circulation method.   The clean air circulation method according to claim 9, wherein when the flow rate of exhausted clean air flowing through the circulation passage is restricted, the clean air is attracted to the attracting unit.

Images