Clean room installation structure for freezing device

Abstract

The present invention ensures a sterile state in a clean room by eliminating the risk of propagation of bacteria due to frost formation and dew condensation.　A holding window 12a into which a freezing device 11 is fitted is formed penetrating through a wall section 12 that configures a clean room 13 and has a back space 15 on a rear surface side thereof, and a casing 11b of the freezing device 11 is fitted into and held by the holding window 12a. At this time, an opening / closing door 11a of the freezing device 11 is exposed at a surface on the clean room 13 side of the wall section 12. A refrigerant supply passage 14 for supplying a refrigerant to the freezing device 11 is provided in the back space 15 together with a refrigerant container 16, and the portion where frost and dew condensation are likely to occur is thereby isolated.

Description

Cleanroom installation structure for freezing equipment

[0001] This invention relates to a structure for installing a freezing device using a refrigerant such as liquid nitrogen in a cleanroom.

[0002] A freezing system that uses a refrigerant requires a configuration for supplying the refrigerant to the system, namely a refrigerant container for storing the refrigerant and a refrigerant supply path for transporting the refrigerant from the container. Until now, the refrigerant supply path has been located in a cleanroom along with the freezing system.

[0003] However, since extremely cold liquids are used as refrigerants, frost and condensation occur on the surface of the pipes that make up the refrigerant supply path.

[0004] Cleanrooms require a certain level of cleanliness depending on the level of cleanliness, and biological cleanrooms in particular require not only air cleanliness but also microbial cleanliness. Cleanrooms that handle living cells and tissues for regenerative medicine and other purposes must be maintained in a particularly sterile state. However, as mentioned above, frost and condensation on the pipes supplying refrigerant are unavoidable, and there is a risk that moisture will cause bacterial growth. Even if moisture is wiped away after each freezing process, complete removal of moisture is difficult, so there is a concern about the risk of bacterial growth.

[0005] The main objective of this invention is to eliminate the risk of bacterial growth caused by frost and condensation.

[0006] To that end, this invention provides the following installation structure for a freezing device in a cleanroom.

[0007] In other words, the installation structure of the freezing device consists of a wall that constitutes a cleanroom, a clean space, and has a back space on the rear side. A through-hole is formed in the wall into which the freezing device is fitted, and the housing of the freezing device is fitted and held in place by the window. At this time, the opening and closing door of the freezing device is exposed on the side of the wall that faces the clean space. The refrigerant supply passage that supplies refrigerant to the freezing device is provided in the back space on the opposite side of the wall from the clean space.

[0008] In this configuration, the wall isolates the refrigerant supply path, which is prone to frost and condensation, into a back space, thereby eliminating the risk of bacterial growth.

[0009] According to this invention, a configuration is adopted in which a wall is provided to separate the space containing the refrigerant supply path from the clean space while holding the freezing device in a penetrating state, thereby preventing the spread of germs caused by frost and condensation on the refrigerant supply path from reaching the clean space, and maintaining the clean space in a sterile state.

[0010] FIG. 1 is a schematic diagram of a clean room installation structure for a freezing device.

[0011] An embodiment of the present invention will be described below with reference to the drawings.

[0012] 1 shows a schematic structure of a clean room installation structure (hereinafter referred to as "installation structure") for a freezing device 11. This installation structure is suitable for installing a freezing device 11 that uses a refrigerant in a clean room, particularly a biological clean room where living cells and tissues are handled, and has a configuration that maintains the clean room in a sterile state.

[0013] In this configuration, the freezing device 11 is held in a manner that allows it to penetrate the wall 12, thereby dividing the space. That is, the door 11a of the freezing device 11 is positioned in the clean space, i.e., on the clean room 13 side. On the other hand, the portion opposite the door 11a, together with the refrigerant supply line 14 that supplies refrigerant to the freezing device 11, is positioned in the back space 15 on the opposite side of the clean room 13. The wall 12 may be an existing wall constituting the clean room 13 or a wall that is added later. The thickness of the wall 12 is thinner than the depth of the freezing device 11. In this example, one side of the space divided by the wall 12 is the clean space, i.e., the clean room 13, which is a sterility-controlled area, and the other side is the back space 15, i.e., an uncontrolled area. Figure 1 is a perspective view with the wall 12 broken away, showing the clean room 13, which is a sterility-controlled area, and the back space 15, which is an uncontrolled area.

[0014] In the cleanroom 13, the cleanliness of the air is maintained within a predetermined range, and the temperature and humidity are controlled to a certain standard. Clean air is supplied as supply air SA, then discharged as return air RA, and after purification, supplied as supply air SA again. This circulation is carried out while taking in fresh air, and the cleanroom is always maintained at positive pressure. The method of circulating the air may be unidirectional, non-unidirectional, or other methods.

[0015] The freezing device 11 is held in a wall 12 that constitutes the cleanroom 13 and has a back space 15 on the rear side, or in a wall 12 that divides the installation space for the freezing device 11 into two. The above-mentioned installation space is the space that combines the cleanroom 13 and the back space 15.

[0016] The wall 12 completely partitions the space and is composed of vertical surfaces on both sides. A through-hole holding window 12a is formed in the wall 12 at the height where the freezing device 11 is to be installed, into which the freezing device 11 is fitted. In the illustrated example, an example with one freezing device 11 is shown, but it is also possible to have multiple freezing devices 11.

[0017] Here, an overview of the freezing device 11 will be described. The freezing device 11 is a programmable freezer that performs freezing according to a freezing program. As mentioned above, it uses liquefied nitrogen as the refrigerant. Therefore, it requires a refrigerant container 16 that stores liquefied nitrogen and a refrigerant supply line 14 that connects the refrigerant container 16 to the freezing device 11. The freezing device 11 has a so-called front-door structure, with an access door 11a on the front of the housing 11b for opening and closing the interior. While the access door 11a is located on the front of the housing 11b, a connection port (not shown) for connecting the refrigerant supply line 14 and an exhaust port (not shown) for venting the interior are located on the rear side of the housing 11b, opposite the access door 11a. The connection port and exhaust port are located behind the rear surface of the wall 12 when the front portion of the housing 11b is fixed to the wall 12. The exhaust port is connected to an exhaust line 17 for venting vaporized refrigerant to the outside. This exhaust line 17 is provided with an on-off valve 18, the opening and closing of which is controlled by a control unit 19. The freezing device 11 has a cooling function using vaporized refrigerant and a heating function for heating the interior of the freezing device 11.

[0018] When fitting such a freezing device 11 into the retaining window 12a of the wall 12, the portion of the housing 11b facing the door 11a is fitted into the retaining window 12a, leaving the door 11a exposed to the clean space in the wall 12, i.e., the surface facing the clean room 13. The space between the retaining window 12a of the wall 12 to which the freezing device 11 is attached and the housing 11b is sealed. Although this depends on the shape of the housing 11b and the structure of the door 11a, it is desirable to have the freezing device 11 not protrude into the clean room as much as possible. This is to prevent foreign matter from accumulating.

[0019] Although not shown in the drawings, the freezing device 11 is not held only by the holding window 12 a of the wall body 12 , but is supported in the back space 15 by an appropriate support member.

[0020] As a result of the freezing device 11 being held so that its opening faces the clean room 13, a refrigerant supply path 14 for supplying refrigerant to the freezing device 11 is provided in a back space 15 on the opposite side of the wall 12 from the clean space (clean room 13), together with a refrigerant container 16. An exhaust path 17 connected to the exhaust port and a control unit 19 for controlling the opening and closing of an on-off valve 18 of the exhaust path 17 are also provided in the back space 15.

[0021] The control unit 19 and the on-off valve 18 are configured to ensure a positive pressure state in the clean room 13. That is, the control unit 19 controls the on-off valve 18 so that it opens only when the freezing device 11 is in cooling operation and closes the on-off valve 18 when the on-off door 11a is open. Specifically, when the control unit 19 receives an open signal for a supply on-off valve (not shown) that is built into the freezing device 11 and controls the refrigerant supply, it outputs an open signal to the on-off valve 18 of the exhaust path 17 to open the valve. When a signal to close the refrigerant supply on-off valve is received, there is a possibility that the on-off door 11a will be opened, so the control unit 19 outputs a close signal to the on-off valve 18 of the exhaust path 17.

[0022] In this way, by controlling the opening and closing of the valve 18 of the exhaust path 17 only during cooling operation of the freezing device 11, no exhaust is discharged from the exhaust path 17 when the opening and closing door 11a is opened, and a positive pressure state within the clean room 13 is maintained.

[0023] It is advisable to employ a configuration that enhances the reliability of the above control by the control unit 19. In other words, the cooling operation of the freezing device 11 is prevented when the on-off valve 18 of the exhaust path 14 is not operating. Specifically, a limit switch (not shown) that detects the opening and closing of the on-off valve 18 is provided, and the control unit 19 is configured to allow the start of the cooling operation on the condition that the control unit 19 receives an open signal from the limit switch indicating that the on-off valve 18 is open.

[0024] In the installation structure configured as described above, processing such as cell manufacturing is performed in the clean room 13, and when freezing cells or the like, the door 11a of the freezing device 11 is opened and the object is placed inside. The supply of refrigerant is controlled by a predetermined cooling operation based on a program, and the object is frozen as desired. During cooling operation, the control unit 19 opens the on-off valve 18 of the exhaust path 17 to discharge vaporized refrigerant to the outside. During non-cooling operation with the supply on-off valve closed, the control unit 19 closes the on-off valve 18 of the exhaust path 17.

[0025] After the cooling operation is completed, the door 11a is opened to remove the frozen object, but at this time, the valve 18 of the exhaust path 17 is closed, so the positive pressure state inside the clean room 13 is maintained.

[0026] During cooling operation, frost and condensation will form on the surfaces of the pipes that make up the refrigerant supply path 14. However, because the refrigerant supply path 14 is located in the back space 15 and not in the clean room 13, the risk of bacteria breeding within the clean room 13 can be avoided. This allows the clean room 13 to be kept sterile.

[0027] Furthermore, the freezing device 11 has a cooling function using vaporized refrigerant and a heating device that heats the inside of the freezer, so by using the cooling and heating functions to dry up the inside of the freezer after cooling operation, the risk of bacteria breeding in the clean room 13 can be completely eliminated.

[0028] As described above, this installation structure can significantly reduce the risk of bacterial proliferation due to frost and condensation inside the clean room 13, and contributes to ensuring a sterile environment.

[0029] The above configuration is another embodiment of the present invention, and the present invention is not limited to the above configuration, and other configurations can also be adopted.

[0030] For example, the refrigerant may be something other than liquid nitrogen, and the clean room 13 may be something other than a biological clean room for regenerative medicine or the like.

[0031] Since the back space 15 only needs to isolate the refrigerant supply passage 14, the refrigerant container 16 can be placed outside the back space 15.

[0032] The freezing device 11 may have an opening and closing door on its top surface.

[0033] 11...Freezing device 11a...Opening / closing door 11b...Housing 12...Wall 12a...Holding window 13...Clean room 14...Refrigerant supply path 15...Back space 16...Refrigerant container 17...Exhaust path 18...Open / close valve 19...Control unit

Claims

1. An installation structure for a freezing device that uses a refrigerant, comprising: a wall that constitutes a clean room, which is a clean space, and has a back space on the rear side, and a through-hole retaining window into which the freezing device is fitted is formed; the housing of the freezing device is fitted and held in the retaining window, and an opening / closing door of the freezing device is exposed on the surface of the wall facing the clean space; and a refrigerant supply path that supplies refrigerant to the freezing device is provided in the back space on the opposite side of the wall from the clean space.

2. An installation structure for a freezing device that uses a refrigerant, comprising: a wall that separates and divides the installation space into two, one space being a clean space and the other being a back space; a through-hole retaining window formed in the wall into which the freezing device is fitted; a housing of the freezing device fitted and retained in the retaining window; an opening / closing door for the freezing device exposed on the surface of the wall facing the clean space; and a refrigerant supply path for supplying refrigerant to the freezing device provided in the back space on the opposite side of the wall from the clean space.

3. A clean room installation structure for a freezing device according to claim 1 or 2, wherein the freezing device has a cooling function using vaporized refrigerant and a heating device for heating the interior of the freezing device.

4. A clean room installation structure for a freezing device according to claim 1 or claim 2, wherein an on-off valve is provided in an exhaust path connected to the exhaust port of the freezing device, and a control unit is provided to open the on-off valve only when the freezing device is in cooling operation.

5. A clean room installation structure for a freezing device according to claim 1 or 2, wherein the freezing device is a front door type having the opening and closing door on the front side.

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