JP2007083162A - Air filter unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air filter unit capable of being attached to the air passing part of a container in a detachable manner by a simple structure and capable of certainly capturing and removing not only dust but also a gas. <P>SOLUTION: A filter medium 1 is produced by sealing a gas removing agent 11 in a flat bag body 10 comprising a sheet material 10a made of a synthetic resin having air permeability. The filter frame 2 is constituted so as to form the cylindrical shape fitted to the air passing part Ca so as to form a cap shape and opened at its one end 21 closed at its other end 22 by a seat plate 23 having air holes 23a. The air holes 23a of the filter frame 2 is closed from the inside of the filter frame 2 by the filter medium 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air filter unit that is detachably fitted to a ventilation part of a container having a ventilation part and used to keep the air in the container clean.

  Some containers, such as a silicon wafer transport case, require that the air inside the container be kept highly clean in a state in which an object to be stored is stored. In this type of container, it is required that not only dust but also a small amount of gas at the ppb level does not exist inside the container.

  On the other hand, this type of container is provided with a ventilation part called a so-called breathing valve, and therefore it is also required to remove the dust and gas from the air passing through the ventilation part.

  For these reasons, an air filter has been incorporated in the ventilation portion of this type of container.

  However, from the viewpoint of facilitating the reuse of this type of container, such an air filter should be replaceable and easy and should be constructed at a low cost. In addition, such an air filter needs to be able to reliably capture and remove not only dust but also gas.

  The main problem to be solved by the present invention is that the air filter unit has a simple structure and can be removably attached to the vent of this type of container, and can reliably capture and remove not only dust but also gas. The purpose is to provide.

In order to achieve the above object, in the present invention, an air filter unit has the following configurations (1) to (5).
(1) An air filter unit that is detachably fitted to a vent formed in a container and keeps the air in the container clean,
(2) It consists of a filter medium and a filter frame,
(3) The filter medium is formed by enclosing a gas removing agent in a flat bag made of a synthetic resin sheet having air permeability,
(4) The filter frame is fitted to the vent so as to form a cap, or is fitted to form a plug, and one end of the cylinder is opened, and a vent hole is provided at the other end of the cylinder. It is configured to form a cylinder,
(5) The ventilation hole of the filter frame is closed from the inside of the filter frame by the filter medium.

  Such an air filter unit removes the gas to be removed from the air passing through the ventilation portion by the gas removing agent of the filter medium by being fitted to the ventilation portion of the container from the one end side of the tube of the filter frame. Moreover, dust can also be removed from the air passing through the ventilation portion by the filter medium sheet. Since the air filter unit is a simple combination of a filter frame and a filter medium, the air filter unit can be supplied at a low cost and can meet the demand for replacement of the air filter unit when the container is reused.

  Such an air filter unit has a ring body that is press-fitted into the filter frame from one end side of the filter frame. Sometimes it is forced to press.

  In this case, the assembly of the filter medium and the filter frame is easy, and unlike the case where welding or the like is used for this assembly, this assembly does not become a cause of generation of gas from the air filter unit itself. .

  The flat bag body constituting the filter medium may be constituted by a sheet body mainly composed of polytetrafluoroethylene (PTFE).

  PTFE does not generate gas and dust from itself, and does not cause dust or the like generated from the gas removing agent enclosed in the flat bag body to leak out to the outside by this PTFE.

  A flange projecting outward may be formed at the other end of the tube of the filter frame.

  In this case, the state where the air filter unit is plugged into the ventilation portion can be stably maintained by abutting the flange against the inlet of the ventilation portion.

  The air filter unit according to the present invention can be detached from the vent portion of the container that is required to keep the inside of the container highly clean by fitting the filter frame from the one end side of the tube of the filter frame to the vent portion of the container. From the air passing through the ventilation part, dust from the sheet body constituting the filter medium, and gas from the gas removing agent enclosed in the flat bag body constituted by the sheet body. Each can be reliably captured and removed. The air filter unit is formed by combining a filter medium with a filter frame so as to block the ventilation hole of the filter frame from the inside thereof, and has a simple structure, and therefore can be supplied at low cost.

  The best mode for carrying out the present invention will be described below with reference to FIGS.

  Here, FIG. 1 shows a filter medium constituting the air filter unit F according to the embodiment. 2 to 4 show one example of the configuration of the air filter unit F, FIGS. 5 and 6 show another example of the configuration of the air filter unit F, and FIGS. Further, another example of the configuration of the air filter unit F is shown.

  The air filter unit F according to this embodiment is detachably fitted to the ventilation part Ca of the container C provided with the ventilation part Ca and used to keep the air in the container C clean. .

  As this container C, what is sealed in an airtight state is planned in places other than the ventilation part Ca. Typically, in the container C composed of a main body and a lid that closes the opening of the main body, both of them are sealed in an airtight state at the opening of the main body, which is a combination portion of the main body and the lid.

  The ventilation portion Ca is typically provided at one place or two or more places in either or either of the main body and the lid body combined in this way. As such a ventilation part Ca, a ventilation hole Ca ′ that communicates the inside and outside of the container C with a ventilation state, a tubular ventilation path Ca ″, and the like are planned. The ventilation part Ca is, for example, a container when the container C is transported. When the outside Cc becomes low pressure, the air inside the container Cb is discharged to the outside Cc until the pressure inside and outside the container becomes equal. When the outside Cc becomes high pressure, the air outside the container Cc is sent to the inside Cb. It functions to inhale until the internal and external pressures become equal, and is generally called a breathing valve.

  The air filter unit F is attached to the ventilation portion Ca of the container C so as to keep the in-container Cb highly clean.

  As such a container C, typically, a silicon wafer carrying case, an electronic component carrying case, an electronic equipment carrying case, an electronic equipment casing, etc., while ensuring the inside and outside ventilation, the internal air is highly advanced. Things that need to be kept clean are planned.

  In the case of a transport case, typically, after the end of one transport, the inside of the case is cleaned by cleaning or the like, the air filter unit F is replaced, and the transport case is used again.

  The air filter unit F includes a filter medium 1 and a filter frame 2.

  The filter medium 1 is formed by sealing a gas removing agent 11 in a flat bag body 10 made of a synthetic resin sheet body 10a having air permeability.

  In the illustrated example, the flat bag body 10 constituting the filter medium 1 is configured by welding two circular sheet bodies 10a and 10a to the other sheet body 10a at the entire peripheral edge thereof. The gas removing agent 11 is typically filled between the two sheet bodies 10 a and 10 a in the process of generating the flat bag body 10.

  As the gas removing agent 11, fibrous activated carbon, coconut shell activated carbon, silicate porous material, ion exchange resin activated alumina, or the like can be used. These are used in the form of powder or granules, or in the form of a sheet.

  If these activated carbons are used as a support and an acidic compound (for example, a phosphoric acid compound, a sulfuric acid compound, etc.) is supported, it is possible to efficiently capture and remove the alkaline gas in addition to the organic gas.

  Further, when an activated carbon or the like is used as a carrier and an alkali compound (for example, potassium carbonate, sodium carbonate, caustic potassium or the like) is supported, the acidic gas can be efficiently captured and removed in addition to the organic gas. .

  Moreover, if these activated carbons are used as a carrier and a permanganate is supported, sulfur compounds as well as organic gases can be efficiently captured and removed.

  Further, if the gas removing agent 11 is blended with two or more of activated carbon carrying the acidic compound, activated carbon carrying an alkali compound, activated carbon carrying a permanganate, etc., it becomes organic. Three or more kinds of gas, alkaline gas, acid gas, and sulfur compound can be efficiently captured and removed.

  In the illustrated example, the flat bag body 10 is constituted by a sheet body 10a mainly composed of polytetrafluoroethylene.

  Specifically, in the illustrated example, the sheet body 10a includes polyethylene (PE) and polyethylene terephthalate (PET) on both surfaces of a sheet 10b having fine holes obtained by stretching PTFE. The nonwoven fabric 10c made of the composite material is laminated and configured. In the example shown in the figure, the flat bag body 10 is obtained by heat-sealing the sheet body 10a from the state in which the two sheet bodies 10a are overlapped. Although PTFE has a relatively high melting point, the two sheet bodies 10a are appropriately bound by the heat sealing with the nonwoven fabric 10c.

  The filter frame 2 is configured to be fitted to the ventilation portion Ca so as to form a cap or to be fitted to form a plug.

  That is, the filter frame 2 is configured to have a cylindrical shape in which the cylinder end 21 is opened, and the seat plate 23 is provided with a vent hole 23a at the cylinder other end 22.

  Specifically, in the illustrated example, the cylindrical portion 20 that forms the main body of the filter frame 2 is configured to have a cylindrical shape. The seat plate 23 is configured to have a disc shape having an outer diameter larger than the outer diameter of the cylindrical portion 20, and the outer peripheral portion of the seat plate 23 is the outer peripheral surface of the cylindrical portion 20 on the other end 22 side. Overhangs outside. Accordingly, the filter frame 2 includes a flange 24 that projects outwardly from the other end 22 of the cylinder.

  The seat plate 23 is formed with a vent hole 23a. The ventilation hole Ca ′ is closed from the inside of the filter frame 2 by the filter medium 1.

  In the illustrated example, the air filter unit F has a ring body 3 that is press-fitted into the filter frame 2 from the tube end 21 side of the filter frame 2. That is, the outer diameter of the ring body 3 is equal to or slightly larger than the inner diameter of the tubular portion 20 of the filter frame 2. The filter medium 1 is configured to have an outer diameter substantially equal to the inner diameter of the cylindrical portion 20. Then, after the filter medium 1 is inserted into the cylindrical portion 20 so as to close the vent hole 23a from the cylinder one end 21 side, the ring body 3 is inserted into the cylindrical section 20 from the cylinder one end 21 side by the ring body 3. The filter frame 2 and the filter medium 1 are integrated with each other until the peripheral edge 12 of 1 is pressed against the inner surface 23b of the seat plate 23 of the filter frame 2 while being elastically deformed.

  Such an air filter unit F removes the gas to be removed from the air passing through the ventilation portion Ca by the gas removing agent 11 of the filter medium 1 by being fitted to the ventilation portion Ca of the container C from the tube end 21 side of the filter frame 2. . Moreover, dust can also be removed from the air passing through the ventilation portion Ca by the sheet body 10 a of the filter medium 1. Since the air filter unit F is simply formed by combining the filter frame 2 and the filter medium 1, the air filter unit F can be supplied at a low cost and meets the demand for replacement of the air filter unit F when the container C is reused.

  In this embodiment, the sheet body 10a constituting the flat bag body 10 of the filter medium 1 is mainly made of PTFE, and this PTFE does not generate gas and dust from itself, and the flat bag body. The dust generated from the gas removing agent 11 enclosed in 10 is not leaked to the outside.

  Further, in this embodiment, the filter medium 1 is combined with the filter frame 2 so that the vent hole 23a of the seat plate 23 of the filter frame 2 is closed by the ring body 3 press-fitted into the filter frame 2. Therefore, the assembly of the filter medium 1 and the filter frame 2 is easy, and unlike the case where welding or the like is used for this assembly, this assembly does not become a cause of generation of gas from the air filter unit F itself.

  When the air filter unit F is fitted to the ventilation part Ca of the container C so as to form a cap shape, the cylindrical part 20 of the filter frame 2 is formed outside the ventilation part Ca whose inner diameter is configured as a tubular ventilation path Ca ″. It is configured to be equal to or slightly smaller than the diameter, thereby enabling such fitting in an airtight state (FIG. 3).

  Further, the tubular portion 20 of the filter frame 2 is configured such that when the air filter unit F is fitted to the vent portion Ca of the container C so as to form a plug shape, the outer diameter thereof is a tubular vent passage Ca "or a vent hole Ca '. It is configured to be equal to or slightly larger than the hole diameter of the ventilation portion Ca. Thereby, it is possible to perform such fitting in an airtight state (FIGS. 6 and 8). Thus, the fitted state of the plug is stably maintained.

  The filter frame 2 is typically made of a synthetic resin from the viewpoint of such fitting in an airtight state. The ring body 3 is also typically made of a synthetic resin from the viewpoint of enabling the press-fitting. As such a synthetic resin, acrylic resin, polycarbonate, polyethylene, polypropylene, ABS resin and the like can be used.

  A plurality of ventilation holes Ca 'in the filter frame 2 may be provided with a gap between the ventilation holes Ca' adjacent in the circumferential direction as in the examples shown in FIGS. In this case, the pressing piece 25 of the filter medium 1 is between the adjacent vent holes Ca '.

  In the example shown in FIG. 7, the pressing piece 25 of the filter medium 1 is provided in a spanning manner in the diameter direction of the vent hole Ca ′.

Cutaway perspective view of the main part of the filter medium 1 Plan view Cross-sectional configuration diagram showing the same use state (position along line AA in FIG. 2) Exploded perspective view of air filter unit F Plane configuration diagram of another example of air filter unit F Cross-sectional configuration diagram showing the same usage state (position BB line in FIG. 5) Planar configuration diagram of still another example of the air filter unit F Cross-sectional configuration diagram showing the same use state (CC line position in FIG. 7)

Explanation of symbols

C container Ca ventilation part F air filter unit 1 filter medium 10 flat bag body 11 gas removal agent 2 filter frame 21 one end of the cylinder 22 the other end of the cylinder 23 a seat plate 23a a vent hole

Claims (4)

An air filter unit that is detachably fitted to a vent formed in a container to keep the air in the container clean,
It consists of a filter medium and a filter frame,
The filter medium is formed by enclosing a gas removing agent in a flat bag made of a synthetic resin sheet having air permeability,
The filter frame has a cylindrical shape that is fitted to the vent so as to form a cap, or is fitted so as to form a plug, with one end opened and a vent provided at the other end. Configured to make,
An air filter unit characterized in that the ventilation hole of the filter frame is closed from the inside of the filter frame by the filter medium.   It has a ring body that is press-fitted into the filter frame from one end of the tube of the filter frame, and the periphery of the filter medium is pressed against the inner surface of the other end of the tube of the filter frame by the press-fitted ring body. The air filter unit according to claim 1, wherein:   3. The air filter unit according to claim 1, wherein the flat bag body constituting the filter medium is composed of a sheet body mainly composed of polytetrafluoroethylene.   The air filter unit according to any one of claims 1 to 3, wherein a flange projecting outward is formed at the other end of the tube of the filter frame.

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