Container for cryopreservation and transportation

An object of the present invention is to provide a container for cryopreservation and transportation which is excellent in maintainability and can appropriately control the temperature of an object to be frozen. The present invention provides a container for cryopreservation and transportation used to transport an object to be frozen, including: a thermal insulation container having an upper opening; a thermal insulation lid which closes the upper opening of the thermal insulation container; and a cooling unit which is held in the thermal insulation container while absorbing liquid nitrogen, wherein a housing space for accommodating a storage tool for storing the object to be frozen is provided inside the thermal insulation container, and the cooling unit is detachable through the upper opening of the thermal insulation container while the storage tool located in the housing space is housed in the thermal insulation container.

This application is the U.S. national phase of International Application No. PCT/JP2021/007818 filed Mar. 2, 2021, which designated the U.S. and claims priority to JP 2020-039093 filed Mar. 6, 2020, JP 2020-039094 filed Mar. 6, 2020, the entire contents of each of which are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a container for cryopreservation and transportation of an object to be frozen.

BACKGROUND ART

For example, in medical fields such as infertility treatment and regenerative medicine, and in research fields such as the development of new drugs, in order to prevent deterioration of biological samples such as sperm, egg cells, embryos, blood, and cells (hereinafter, simply referred to as “sample”), the sample is generally cryopreserved. For cryopreservation, a cryopreservation container containing liquid nitrogen (boiling point: −196° C.) is widely used because the sample can be stored in a stable state for a long period of time. Further, it is also required to freeze and store articles for example, medicines such as cell-based drugs, small molecule drugs, and vaccines, drugs such as chemical substances, and foods in an ultra-low temperature environment. Hereinafter, an object to be frozen such as a sample or an article is referred to as “object to be frozen”.

Further, as the cryopreservation container, there is a dry shipper (container for cryopreservation and transportation) used for transporting an object to be frozen (see, for example, Patent Document 1 below). The dry shipper includes a thermal insulation container having an upper opening, a thermal insulation lid that closes the upper opening of the thermal insulation container, and an absorbent material that absorbs liquid nitrogen.

In the dry shipper, liquid nitrogen is held in the thermal insulation container in a state of being absorbed by the absorbent material, so even if the thermal insulation container collapses, there is no concern that liquid nitrogen will leak to the outside through the upper opening of the thermal insulation container. Therefore, it is possible to transport an object to be frozen more safely while keeping the temperature inside the thermal insulation container at an ultra-low temperature (−150° C. or lower).

PRIOR ART DOCUMENTS

Patent Documents

SUMMARY OF INVENTION

Problem to be Solved by the Invention

The conventional dry shipper explained above is used in a state at which liquid nitrogen is absorbed by an absorbent material attached to the inside of the thermal insulation container. Therefore, since the absorbent material cannot be removed, it is difficult to perform maintenance such as cleaning and disinfection of the inside of the thermal insulation container after use. In addition, although the dry shipper is used repeatedly, in order to improve the absorption efficiency of liquid nitrogen, it is necessary to dry the absorbent material sufficiently after use and then absorb the liquid nitrogen into the absorbent material before use.

In addition, in the dry shipper, the liquid nitrogen absorbed by the absorbent material becomes a gas phase state in the thermal insulation container and gradually decreases. Therefore, if the liquid nitrogen absorbed by the absorbent material decreases, it is necessary for the absorbent material to reabsorb liquid nitrogen. In this case, it is necessary to temporarily remove the storage tool such as the canister that stores an object to be frozen from the thermal insulation container. Furthermore, in order to control the temperature of an object to be frozen, it is necessary to promptly transfer the storage equipment taken out from the thermal insulation container to another cryopreservation container or the like.

The present invention has been proposed in view of such conventional circumstances, and an object of the present invention is to provide a container for cryopreservation and transportation which is excellent in maintainability and can appropriately control the temperature of an object to be frozen.

Means for Solving the Problem

In order to achieve the object, the present invention provides the following container for cryopreservation and transportation.

[1] A container for cryopreservation and transportation of an object to be frozen including:

a thermal insulation container having an upper opening;a thermal insulation lid which closes the upper opening of the thermal insulation container; anda cooling unit which is held in the thermal insulation container while absorbing liquid nitrogen,wherein a housing space for accommodating a storage tool for storing the object to be frozen is provided inside the thermal insulation container, andthe cooling unit is detachable through the upper opening of the thermal insulation container while the storage tool located in the housing space is housed in the thermal insulation container.
[2] The container for cryopreservation and transportation according to [1],wherein the cooling unit is provided with a through hole for partitioning the housing space in the vertical direction.
[3] The container for cryopreservation and transportation according to [1],wherein the cooling unit includes a cooling portion which is provided with an absorbent material that absorbs liquid nitrogen, and a thermal insulation portion which is located on the cooling portion and provided with a thermal insulation material.
[4] The container for cryopreservation and transportation according to [3],wherein the cooling unit includes a fixing portion which is located on the thermal insulation portion and fixed to the upper portion of the thermal insulation container.
[5] The container for cryopreservation and transportation according to [1],wherein a plurality of the cooling units are provided so as to surround the housing space.
[6] The container for cryopreservation and transportation according to [1],wherein a support portion for supporting the storage tool is provided at the inner bottom portion of the thermal insulation container.
[7] The container for cryopreservation and transportation according to [6],wherein the support portion is in contact with the cooling unit which is held in the thermal insulation container to restrict the movement of the cooling unit in the radial direction of the thermal insulation container.
[8] The container for cryopreservation and transportation according to [1],wherein the cooling unit includes a cooling portion which is provided with an absorbent material that absorbs liquid nitrogen, a thermal insulation portion which is provided with a thermal insulation material and located on the cooling portion, and a positioning portion which is located on the thermal insulation portion,a guide member is provided at the upper portion of the thermal insulation container.the guide member includes a guide portion having a shape corresponding to the positioning portion, andthe cooling unit is guided in the vertical direction of the thermal insulation container along the guide member, the positioning portion is located inside the guide portion, and the cooling unit is positioned with respect to the guide member.
[9] The container for cryopreservation and transportation according to [8],wherein a pressing member is detachably provided at the upper portion of the guide member, andthe pressing member is into contact with the cold insulation unit which is held in the thermal insulation container to restrict the movement of the cold insulation unit in the vertical direction of the thermal insulation container.
[10] The container for cryopreservation and transportation according to [1],wherein the thermal insulation lid is provided with a thermal insulation convex portion to be inserted into the housing space.
[11] The container for cryopreservation and transportation according to [1],wherein the thermal insulation container has a vacuum insulated structure.

Effects of the Invention

According to the present invention, it is possible to provide a container for cryopreservation and transportation which is excellent in maintainability and can appropriately control the temperature of an object to be frozen.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Note that the materials and the like exemplified in the following description are examples, and the present invention is not necessarily limited thereto, and the present invention can be appropriately modified and carried out without changing the gist thereof.

First Embodiment

First, as the first embodiment of the present invention, a dry shipper1A shown inFIGS.1to13will be described.

FIG.1is an exploded perspective view showing the configurations of a dry shipper1A and a storage tool50.FIG.2is a partial cross-sectional perspective view showing a state in which the storage tool50is housed in the dry shipper1A.FIG.3is a plan view showing a state at which the storage tool50is housed in the dry shipper1A.FIG.4is a half cross-sectional view showing a state in which the storage tool50is housed in the dry shipper1A.FIG.5is an exploded perspective view showing a thermal insulation container2and a plurality of cooling units4constituting the dry shipper1A.FIG.6is a partial cross-sectional perspective view showing a state in which the plurality of cooling units4are held in the thermal insulation container2.FIG.7is a plan view showing a state in which the plurality of cooling units4are held in the thermal insulation container2.FIG.8is a half cross-sectional view showing a state in which the plurality of cooling units4are held in the thermal insulation container2.FIG.9is a plan view showing the configuration of the thermal insulation container2.FIG.10is a partial cross-sectional perspective view showing the configuration of the thermal insulation container2.FIG.11is a partial cross-sectional perspective view showing a state in which the storage tool50is housed in the thermal insulation container2with the plurality of cooling units4removed.FIG.12is a perspective view showing the configuration of the cooling unit4.FIG.13is a perspective view showing a modified example of the cooling unit4.

As shown inFIGS.1to4, the dry shipper1A of the present embodiment is a container for cryopreservation and transportation used for transporting an object to be frozen (not shown). The dry shipper1A houses the storage tool50that stores a plurality of objects to be frozen inside, and transports the objects to be frozen while keeping the inside at an ultra-low temperature (−150° C. or lower) by liquid nitrogen in a vapor phase state.

As shown inFIG.1, the storage tool50is a rack for storing a plurality of objects to be frozen in the vertical direction (height direction). The storage tool50is made of a sheet metal such as stainless steel or an aluminum alloy, and has a substantially rectangular parallelepiped shape extending in the vertical direction as a whole. Further, a handle50ais provided at the upper central portion of the storage tool50.

The storage tool50may be any storage tool as long as it can store objects to be frozen which are to be transported, and is not limited to a rack. Any storage tool such as a drawer or a canister can be used. Further, the configuration of the storage tool50is not particularly limited as long as it can be accommodated inside the dry shipper1A of the present embodiment.

As shown inFIG.1, the dry shipper1A of the present embodiment includes the thermal insulation container2having an upper opening2a, a thermal insulation lid3for closing the upper opening2aof the thermal insulation container2, the plurality of (four in the present embodiment) cooling units4which are held in the container2in a state of absorbing liquid nitrogen, a guide member5which is provided at the upper portion of the thermal insulation container2, and a pressing member6which is detachably provided at the upper portion of the guide member5.

As shown inFIGS.9and10, the thermal insulation container2is a double container having a vacuum insulation structure. Specifically, the container body2includes an outer container7and an inner container8which are bottomed cylindrical shaped, and made of a metal such as an aluminum alloy or stainless steel, a thermal insulation cylinder9which is cylindrical shaped, and made of a thermal insulation material such as an epoxy resin, an upper wall plate10which is circular ring-shaped, and made of a metal such as an aluminum alloy or stainless steel, and a lower support11which is rod-shaped, and made of a thermal insulation material such as an epoxy resin.

In the thermal insulation container2, the inner container8is concentrically housed inside the outer container7, and a space between the center of the inner bottom surface of the outer container7and the center of the outer bottom surface of the inner container8is supported by a lower support11. Further, in a state at which the open end portion of the outer container7and the outer peripheral end portion of the upper wall plate10are overlapped with each other, the overlapped portions are joined over the entire circumference. The thermal insulation cylinder9is attached between the open end of the inner container8and the inner peripheral end of the upper wall plate10so as to be flush with the inner peripheral surface of the inner container8.

As a result, the upper end portion of the thermal insulation cylinder9is opened in a circular shape in plan view as the upper opening portion2aof the thermal insulation container2. Further, the inside of the thermal insulation container2is formed in a cylindrical shape toward the bottom of the inner container8while maintaining the same diameter as that of the upper opening2a.

Further, a vacuum thermal insulation layer12is provided by the outer container7, the upper wall plate10, the inner container8, and the thermal insulation cylinder9. The vacuum thermal insulation layer12is formed in a high vacuum by degassing from the degassing port (not shown) provided at the upper wall plate9and then closing the degassing port with a plug13.

A support portion14for supporting the storage tool50is provided inside the thermal insulation container2. The support portion14includes a leg portion14athat stands upward from the central portion of the bottom surface of the inner container8, and a support plate14battached to the tip of the leg portion14a. Further, the support plate14bis formed in a rectangular shape (square shape in the present embodiment) in plan view in accordance with the shape of the storage tool50. As shown inFIG.11, the storage tool50can be placed on the support plate14b.

As shown inFIG.1, the thermal insulation lid3is made of a metal such as an aluminum alloy or stainless steel, and includes a top wall portion3awhich is circular shaped in plan view and a peripheral wall3bwhich protrudes downward from the periphery of the top wall portion3a. Further, a thermal insulation convex portion15is provided so as to protrude from the central portion of the lower surface of the thermal insulation lid3. The thermal insulation convex portion15is made of a thermal insulation material using a foamed resin such as polystyrene, polyethylene, or polyurethane, and has a length (height) corresponding to that of the thermal insulation cylinder9, and a substantially rectangular parallelepiped shape extending in the vertical direction as a whole.

As shown inFIGS.1to4and6to8, a housing space K for accommodating the storage tool50is provided inside the thermal insulation container2. A plurality of cooling units4are held in the thermal insulation container2in a state of surrounding the housing space K, and are detachably provided into the thermal insulation container2.

In the dry shipper1A of the present embodiment, four cooling units4are detachably provided at positions surrounding four sides of the housing space K, which is partitioned in a substantially rectangular parallelepiped shape in accordance with the shape of the storage tool50. Further, in the dry shipper1A of the present embodiment, when the thermal insulation lid3closes the upper opening2aof the thermal insulation container2, the thermal insulation convex portion15is inserted into the storage space K from above.

As shown inFIG.12, each cooling unit4includes a cooling portion16which is provided with an absorbent material that absorbs liquid nitrogen, a thermal insulation portion17which is located on the cooling portion16, and provided with a thermal insulation material, and a positioning portion18which is located on the thermal insulation portion17.

The cooling portion16is a case for storing the absorbent material. For example, the cooling portion16is made of metal such as an aluminum alloy, stainless steel, or copper, but other materials may be used. Further, on the side surface of the case, slits or holes through which liquid nitrogen passes are provided. As the absorbent material, for example, a resin, fiber, cloth or the like capable of absorbing liquid nitrogen can be used. The cooling portion16has a length (height) corresponding to that of the inner container8, and has a substantially rectangular parallelepiped shape extending in the vertical direction as a whole.

The thermal insulation portion17is made of a thermal insulation material using a foamed resin such as polystyrene, polyethylene, or polyurethane, and has a length (height) corresponding to that of the thermal insulation cylinder9, and a substantially rectangular parallelepiped shape extending in the vertical direction as a whole.

The positioning portion18is made of a metal such as an aluminum alloy or stainless steel, has a thickness corresponding to that of the guide member5, and is formed in a substantially rectangular flat plate shape. Further, the positioning portion18is provided with a pair of positioning convex portions18aprotruding from both sides in the width direction.

The cooling unit4has a shape in which the outer surface is curved as a whole in accordance with the shape of the thermal insulation container2, and the inner surface is flat as a whole in accordance with the shape of the housing space K. Further, a handle4ais provided at the upper portion of the positioning portion18.

The cooling unit4may have a shape in which only the outer surface of the cooling portion16is flat, as shown inFIG.13, for example. This makes it possible to simplify the shape of the case of the cooling portion16.

As shown inFIGS.1to11, the guide member5is made of a metal such as an aluminum alloy or stainless steel, and has a substantially circular flat plate shape as a whole in accordance with the shape of the upper portion of the thermal insulation container2. The guide member5is attached to the upper wall plate10by screwing in a state of being overlapped with the upper wall plate10. The guide member5may be integrally formed with the upper wall plate10. Further, the thermal insulation material explained above or the like may be used for the guide member5.

An opening5ais provided at the center of the guide member5. The opening5aopens in a substantially circular shape in plan view in accordance with the shape of the upper opening2aof the thermal insulation container2.

The guide member5has a plurality of (four in this embodiment) guide portions19at positions corresponding to each of the plurality of cooling units4. Each guide portion19is cut out in accordance with the shape of the positioning portion18of each cooling unit4. Further, the guide portion19is provided with a pair of positioning recesses19ato which the pair of positioning protrusions18aare engaged.

In the dry shipper1A of the present embodiment, each cooling unit4is inserted into the inside of the thermal insulation container2along each guide portion19. Further, the cooling unit4is guided in the vertical direction of the thermal insulation container2along the guide portion19. By locating the positioning portion18inside the guide portion19, the cooling unit4is positioned with respect to the guide member5.

This makes it possible to hold the cooling unit4in the thermal insulation container2. Further, the housing space K explained above is partitioned inside the plurality of cooling units4held in the thermal insulation container2.

Further, in the dry shipper1A of the present embodiment, the inner surface of the cooling units4which are held in the thermal insulation container2is brought into contact with the support plate14b(support portion14). Thereby, the movement of the cooling units4in the radial direction of the thermal insulation container2is restricted. This makes it possible to hold the cooling units4in the thermal insulation container2in a stable state during transportation of the dry shipper1A.

The shapes of the guide portion19and the positioning portion18are not particularly limited to the shapes above, and can be changed as appropriate. Further, in the present embodiment, a positioning convex portion18ais provided at the positioning portion18and a positioning concave portion19ais provided at the guide portion19. However, a positioning recess may be provided at the positioning portion18, and a positioning protrusion may be provided at the guide portion19. Further, each of the positioning portion18and the guide portion19may have a positioning convex portion and a positioning concave portion which are engaged with each other.

The pressing member6is made of a metal such as an aluminum alloy or stainless steel, and has a substantially circular flat plate shape as a whole in accordance with the shape of the opening5aof the guide member5. Further, an opening6ais provided in the central portion of the pressing member6. The opening6aopens in a substantially rectangular shape (square shape in the present embodiment) in plan view in accordance with the shape of the housing space K.

Further, the pressing member6has an outer peripheral wall portion6bprotruding downward from the outer periphery thereof, and an inner peripheral wall portion6cprotruding downward from the inner periphery thereof. The outer peripheral wall portion6band the inner peripheral wall portion6care provided so as to project in accordance with the height of the handle4aof the cooling unit4.

The pressing member6is fixed to the guide member5by screwing while covering the upper portion of the plurality of cooling units4. The fixing means of the pressing member6to the guide member5is not limited to such screwing, and any fixing means can be used. Further, the thermal insulation material explained above may be used for the pressing member6.

In the dry shipper1A of the present embodiment, the pressing member6is brought into contact with each cooling unit4held in the thermal insulation container2, thereby restricting the movement of each cooling unit4in the vertical direction of the thermal insulation container2. This makes it possible to hold the cooling unit4in the thermal insulation container2in a stable state during transportation of the dry shipper1A.

Since the pressing member6is not always necessary, it may be omitted in some cases. In this case, an arbitrary fixing means for fixing the cooling unit4to the guide member5may be provided.

In the dry shipper1A of the present embodiment having the above configuration, while the storage tool50located in the housing space K is housed in the thermal insulation container2, each cooling unit4can be individually attached or detached through the upper opening2aof the thermal insulation container2.

Therefore, in the dry shipper1A of the present embodiment, when the amount of liquid nitrogen absorbed by any of the cooling units4decreases, it is possible to have the cooling unit4reabsorb liquid nitrogen or replace it with another cooling unit4that has absorbed liquid nitrogen without removing the storage tool50from the thermal insulation container2.

As a result, it is possible to suppress the temperature rise of an object to be frozen and keep an object to be frozen in a stable state at a low temperature. In addition, it is possible to appropriately control the temperature of an object to be frozen while suppressing the influence on the ambient temperature change.

Further, in the dry shipper1A of the present embodiment, it is possible to easily remove the plurality of cooling units4after use. As a result, operations such as cleaning and disinfection of the inside of each cooling unit4and thermal insulation container2can be performed easily and in a short time, and excellent maintainability can be obtained.

Second Embodiment

Next, as a second embodiment of the present invention, a dry shipper1B shown inFIGS.14to17will be described.

FIG.14is a partial cross-sectional perspective view showing a thermal insulation container2and a plurality of cooling units4constituting the dry shipper1B.FIG.15is a plan view showing a state in which the plurality of cooling units4are housed inside the thermal insulation container2.FIG.16is a half cross-sectional view showing a state in which the plurality of cooling units4are housed inside the thermal insulation container2.FIG.17is a partial cross-sectional perspective view showing the thermal insulation container2. Further, in the following description, explanations of the same parts as those of the dry shipper1A will be omitted, and the same reference numerals will be given in the figures.

As shown inFIGS.14to17, the dry shipper1B of the present embodiment is provided with a substantially columnar housing space K inside the thermal insulation container2, and a plurality of (six in the present embodiment) cooling units4are detachably held surrounding the housing space K. Other than this structure, the dry shipper1B has basically the same configuration as that of the dry shipper1A above.

A support portion14of the thermal insulation container2has a support plate14bformed in a circular shape in plan view, and a tubular portion14cprotruding upward from the periphery of the support plate14b.

Each cooling unit4has a shape in which the outer surface is curved as a whole in accordance with the shape of the thermal insulation container2, and the inner surface is curved as a whole in accordance with the shape of the housing space K. Further, a positioning portion18is provided with a positioning convex portion18aprotruding outward from the central portion of the outer peripheral end portion.

A guide member5has a plurality of (six in this embodiment) guide portions19at positions corresponding to each of the plurality of cooling units4. The guide portion19is provided with a positioning recess19awith which the positioning protrusion18ais engaged.

In the dry shipper1B of the present embodiment, each cooling unit4is inserted into the inside of the thermal insulation container2along each guide portion19. Further, the cooling unit4is guided in the vertical direction of the thermal insulation container2along the guide portion19, and by locating the positioning portion18inside the guide portion19, the cooling unit4is positioned with respect to the guide member5.

This makes it possible to hold the cooling unit4in the thermal insulation container2. Further, the housing space K above is partitioned inside the plurality of cooling units4held in the thermal insulation container2.

Further, in the dry shipper1B of the present embodiment, the inner surface of the cooling unit4held in the thermal insulation container2is in contact with the support plate14band the cylindrical portion14c(support portion14). This regulates the movement of the cooling unit4in the radial direction of the thermal insulation container2. As a result, it is possible to hold the cooling unit4in the thermal insulation container2in a stable state during the transportation of the dry shipper1B.

Although not shown, the storage tool50is not particularly limited as long as it can be accommodated inside the dry shipper1B of the present embodiment (housing space K). Further, the thermal insulation convex portion15of the thermal insulation lid3has a substantially cylindrical shape extending in the vertical direction as a whole in accordance with the shape of the housing space K. The opening6aof the pressing member6has a circular opening in plan view in accordance with the shape of the housing space K.

In the dry shipper1B of the present embodiment having the configuration explained above, it is possible to obtain the same effects as those of the dry shipper1A above. That is, each cooling unit4can be individually attached or detached through the upper opening2aof the thermal insulation container2while the storage tool50located in the housing space K is housed in the thermal insulation container2.

Therefore, in the dry shipper1B of the present embodiment, when the amount of liquid nitrogen absorbed by any of the cooling units4decreases, it is possible to have the cooling unit4reabsorb liquid nitrogen or replace it with another cooling unit4that has absorbed liquid nitrogen without removing the storage tool50from the thermal insulation container2.

As a result, it is possible to suppress the temperature rise of an object to be frozen and keep an object to be frozen in a stable state at a low temperature. In addition, it is possible to appropriately control the temperature of an object to be frozen while suppressing the influence of the ambient temperature change.

Further, in the dry shipper1B of the present embodiment, it is possible to easily remove the plurality of cooling units4after use. As a result, operations such as cleaning and disinfection of the inside of each cooling unit4and thermal insulation container2can be performed easily and in a short time, and excellent maintainability can be obtained.

Third Embodiment

Next, as a third embodiment of the present invention, a dry shipper1C shown inFIGS.18to22will be described.

FIG.18is an exploded perspective view showing the dry shipper1C.FIG.19is a partial cross-sectional perspective view showing a thermal insulation container2and a cooling unit40constituting the dry shipper1C.FIG.20is a plan view showing a state in which the cooling unit40is held in the thermal insulation container2.FIG.21is a half cross-sectional view showing a state in which the cooling unit40is held in the thermal insulation container2.FIG.22is a partial cross-sectional perspective view showing the thermal insulation container2. Further, in the following description, explanations of the same parts as those of the dry shipper1A will be omitted, and the same reference numerals will be given in the figures.

As shown inFIGS.18to22, the dry shipper1C of the present embodiment includes the cooling unit40instead of the plurality of cooling units4. Further, the pressing member6is omitted. Other than those, the dry shipper1C has basically the same configuration as that of the dry shipper1A above.

The cooling unit40includes a cooling portion41which is provided with an absorbent material that absorbs liquid nitrogen, a thermal insulation unit42which is provided with a thermal insulation material located on the cooling portion41, a fixing member43which is positioned on the thermal insulation container42, and fixed to the upper portion of the thermal insulation container2, and a through hole44penetrating the central portion of the cooling portion41, the thermal insulation portion42, and the fixing member43in the vertical direction (height direction).

In the dry shipper1C of the present embodiment, the housing space K is partitioned in a substantially rectangular parallelepiped shape by the through hole44. Further, when the thermal insulation lid3closes the upper opening2aof the thermal insulation container2, the thermal insulation convex portion15is inserted into the storage space K (through hole44) from above.

The cooling portion41is a case for storing the absorbent material. For the case, for example, a metal such as an aluminum alloy, stainless steel, or copper can be used, but other materials may be used. Further, on the side surface of the case, slits or holes through which liquid nitrogen passes are provided. As the absorbent material, for example, a resin, fiber, cloth or the like capable of absorbing liquid nitrogen can be used.

The cooling portion41has a substantially cylindrical shape extending in the vertical direction as a whole in accordance with the shape of the inside of the inner container8. Further, in the central portion of the cooling portion41, a square cylindrical hole portion41aconstituting the through hole44is provided so as to penetrate in the vertical direction.

The thermal insulation portion42is made of a thermal insulation material using a foamed resin such as polystyrene, polyethylene, or polyurethane, and has a substantially cylindrical shape extending in the vertical direction as a whole in accordance with the shape of the inside of the thermal insulation cylinder9. Further, in the central portion of the thermal insulation portion42, a square cylindrical hole portion42aconstituting the through hole44is provided so as to penetrate in the vertical direction.

The fixing member43is made of a metal such as an aluminum alloy or stainless steel, and has a substantially circular flat plate shape as a whole in accordance with the shape of the upper portion of the thermal insulation container2. Further, an opening43aconstituting the through hole44is provided in the central portion of the fixing member43. The opening43aopens in a substantially rectangular shape (square shape in the present embodiment) in plan view in accordance with the shape of the through hole44(housing space K). Further, a pair of handles40aare provided at the upper portion of the fixing member43.

In the dry shipper1C of the present embodiment, the cooling unit40is inserted into the inside of the thermal insulation container2through the upper opening2a. This makes it possible to hold the cooling unit40in the thermal insulation container2.

Further, in the dry shipper1C of the present embodiment, the inner surface of the cooling unit40which is held in the thermal insulation container2is brought into contact with the support plate14b(support portion14), so that the movement of the cooling unit40in the radial direction of the thermal insulation container2is restricted. This makes it possible to hold the cooling unit40in the thermal insulation container2in a stable state during transportation of the dry shipper1C.

Further, in the dry shipper1C of the present embodiment, the fixing member43is fixed to the upper wall plate10by screwing in a state of being overlapped with the upper wall plate10. As a result, it is possible to restrict the movement of the cooling unit40in the vertical direction of the thermal insulation container2and to hold the cooling unit40in the thermal insulation container2in a stable state during the transportation of the dry shipper1C.

The fixing means to the upper wall plate10of the fixing member43is not limited to such screwing, and any fixing means can be used.

In the dry shipper1C of the present embodiment having the configuration above, it is possible to obtain the same effects as those of the dry shipper1A above. That is, it is possible to attach or detach the cooling unit40through the upper opening2aof the thermal insulation container2while the storage tool50located in the housing space K is housed in the thermal insulation container2.

Therefore, in the dry shipper1C of the present embodiment, when the amount of liquid nitrogen absorbed by the cooling unit40decreases, it is possible to have the cooling unit40reabsorb liquid nitrogen or replace it with another cooling unit40that has absorbed liquid nitrogen without removing the storage tool50from the thermal insulation container2.

As a result, it is possible to suppress the temperature rise of an object to be frozen and keep an object to be frozen in a stable state at a low temperature. In addition, it is possible to appropriately control the temperature of an object to be frozen while suppressing the influence on the ambient temperature change.

Further, in the dry shipper1C of the present embodiment, it is possible to easily remove the cooling unit40after use. As a result, operations such as cleaning and disinfection of the inside of the cooling unit40and thermal insulation container2can be performed easily and in a short time, and excellent maintainability can be obtained.

The present invention is not necessarily limited to the embodiments above, and various modifications can be made without departing from the spirit of the present invention.

For example, the cooling unit4,40has a configuration in which the thermal insulation portions17and42are integrally provided, but the present invention is not limited to such a configuration. The thermal insulation portion17,42may be provided separately from the cooling unit40.

Further, the cooling unit40has a configuration in which the thermal insulation portion42and the fixing member43are integrally provided, but the present invention is not limited to such a configuration. The fixing member43may be provided separately from the cooling unit40.

EXPLANATION OF REFERENCE NUMERALS