Patent Publication Number: US-2022228789-A1

Title: Freezing transport container, and cryogenic liquefied gas absorber case

Description:
TECHNICAL FIELD 
     The present invention relates to a freezing transport container which stores and transports biological samples in medical and biotechnology fields and the like such as cells in a frozen state, and a cryogenic liquefied gas absorber case which is installed in the freezing transport container and used to keep the inside of the container at a low temperature. 
     BACKGROUND ART 
     A dry shipper with a vacuum heat-insulating structure as a means for transporting a biological sample in a frozen state is known in the art. Since an absorbent material for liquid nitrogen, which is a cryogenic liquefied gas, is arranged inside the dry shipper, and the liquid nitrogen is absorbed by the absorbent material, there is no risk of spilling the liquid nitrogen even if it falls during transportation. 
     For example, Patent Document 1 discloses a cryopreservation container using an impregnating material impregnated with cryogenic liquefied gas such as liquid nitrogen. 
     The cryopreservation container of Patent Document 1 includes a heat-insulating container having a small-diameter sample inlet/outlet and a cylindrical storage area which has a diameter larger than the diameter of the sample inlet/outlet, and is formed below the sample inlet/outlet, and the impregnating material is arranged on the bottom and inner peripheral walls of the heat-insulating container. 
     PRIOR ART DOCUMENTS 
     Patent Literature 
     Patent Document 1: Japanese Patent No. 4881046 
     SUMMARY OF INVENTION 
     Problem to be Solved by the Invention 
     In order to make the cryopreservation container disclosed in Patent Document 1 less susceptible to the influence of the outside air temperature, the sample inlet/outlet has a smaller diameter than that of the storage area for storing the sample. Therefore, it is not possible to take in a large sample such as a bag shape. 
     Further, there is a problem in that since the impregnating material is arranged on the peripheral wall of the sample storage area, the inner diameter of the sample storage area becomes small, and an elongated sample such as a vial can be stored, but a large sample having a bag shape or the like cannot be stored. 
     Further, the impregnating material used in the cryopreservation container disclosed in Patent Document 1 is fixed in a heat-insulating container and cannot be removed. However, it is conceivable that the impregnating material gradually deteriorates reducing the absorption amount of liquid nitrogen or becoming contaminated, and a replaceable structure is required. 
     The present invention has been made to solve such problems, and an object of the present invention is to provide a freezing transport container which can store large samples such as bag shapes and allows easy removal and installation of a cryogenic liquefied gas absorber which is impregnated with cryogenic liquefied gas such as liquid nitrogen, and a cryogenic liquefied gas absorber case which can be installed in the freezing transport container. 
     Means for Solving the Problem 
     In order to solve the problems, the present invention provides the following freezing transport container and cryogenic liquefied gas absorber case. 
     (1) A freezing transport container including a main body which has a heat-insulating structure, an opening at the top, and a bottomed tubular shape, and a lid which is installed at the opening of the main body so as to open and close the opening of the main body, 
     wherein the main body has the same diameter at the opening at the top and the bottom, 
     the freezing transport container further includes a cryogenic liquefied gas absorber case which is installed removably at the bottom of the main body, and 
     the cryogenic liquefied gas absorber case includes a case portion which has a bottomed tubular shape and a cryogenic liquefied gas absorber which is installed replaceably inside the case portion. 
     (2) The freezing transport container according to (1), 
     wherein the case portion is formed by a heat conductor, has a side wall portion arranged along the inner peripheral wall of the main body, and an inner space of the side wall portion functions as a sample storage portion, and 
     a height of the side wall portion is higher than a height of the cryogenic liquefied gas absorber. 
     (3) The freezing transport container according to (1) or (2), 
     wherein the main body having a heat-insulating structure has a vacuum double structure formed by stainless steel, and the case portion is made of aluminum or copper. 
     (4) The freezing transport container according to any one of (1) to (3), 
     wherein the case portion includes a fixing plate, and the fixing plate and the cryogenic liquefied gas absorber are provided with a sample insertion hole which is configured to be received with a sample to be stored. 
     (5) A cryogenic liquefied gas absorber case which is configured to be installed removably on the bottom of a freezing transport container including a main body which has a heat-insulating structure, an opening at the top, a bottomed tubular shape, and the same diameter at the opening at the top and the bottom, and a lid which is installed into the opening in the main body so as to open and close the opening of the main body, 
     wherein the cryogenic liquefied gas absorber case includes a case portion which has a bottomed tubular shape, and a cryogenic liquefied gas absorber which is installed replaceably inside the case portion. 
     (6) A cryogenic liquefied gas absorber case according to (5), 
     wherein the case portion is formed by a heat conductor and has a side wall portion arranged along an inner peripheral wall of the main body, 
     an inner space of the side wall portion functions as a sample storage portion, and 
     a height of the side wall portion is higher than a height of the cryogenic liquefied gas absorber. 
     (7) The cryogenic liquefied gas absorber case according to (5) or (7), 
     wherein the case portion is formed by aluminum or copper. 
     The freezing transport container according to the present invention includes a main body having a heat-insulating structure, an opening at the top, and a bottomed tubular shape, and a lid which is installed at the opening of the main body so as to open and close the opening of the main body, wherein the main body has the same diameter at the opening at the top and the bottom, the freezing transport container further includes a cryogenic liquefied gas absorber case which is installed removably at the bottom of the main body, and the cryogenic liquefied gas absorber case includes a case portion which has a bottomed tubular shape and a cryogenic liquefied gas absorber which is installed replaceably inside the case portion. 
     Since the cryogenic liquefied gas absorber case can be taken out and the cryogenic liquefied gas absorber can be easily replaced, the cryogenic liquefied gas absorber can be recovered against deterioration and contamination. 
     In addition, since the main body has the same diameter at the top and the bottom, the inner space is wide and a large sample such as a bag can be stored, which makes it possible to transport a large sample, which was difficult in the past. 
     Effects of the Invention 
       
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cross-sectional view showing a freezing transport container according to an embodiment of the present invention. 
         FIG. 2  is a diagram showing the appearance of a freezing transport container according to an embodiment of the present invention. 
         FIG. 3  is a perspective view showing a liquid nitrogen absorber case and a case fixture which are taken out from the main body of a freezing transport container. 
         FIG. 4  is a plan view (a) and a cross-sectional view (b) showing a liquid nitrogen absorber case disposed in a freezing transport container according to the embodiment of the present invention. 
         FIG. 5  is an explanatory diagram showing a method for installing a liquid nitrogen absorbent material in a liquid nitrogen absorber case. 
         FIG. 6  is an explanatory diagram showing sample insertion holes according to another embodiment which are provided in a liquid nitrogen absorber installed in a freezing transport container of the present invention. 
         FIG. 7  is an explanatory diagram of a liquid nitrogen absorber case according to another embodiment which is provided in a freezing transport container of the present invention. 
         FIG. 8  is an explanatory diagram showing an internal heat-transfer state in a freezing transport container according to an embodiment of the present invention. 
         FIG. 9  is an explanatory diagram showing an internal heat-transfer state in a conventional freezing transport container which does not include the liquid nitrogen absorber case. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A freezing transport container according to the present embodiment will be described with reference to  FIGS. 1 to 6 . In the following description, a case in which a main body of the freezing transport container is cylindrical will be taken as an example, and liquid nitrogen will be taken as an example of a cryogenic liquefied gas. However, the present invention is not limited thereto. 
     As shown in  FIGS. 1 to 6 , a freezing transport container  1  according to the present embodiment is for transporting a sample while maintaining it in a frozen state. The freezing transport container  1  according to the present embodiment includes a main body  3  having a heat-insulating structure, an opening  3   a  at the top, and a bottomed cylindrical shape; a lid  5  which can open and close the opening  3   a  of the main body  3 ; and a liquid nitrogen absorber case  7  which is removably installed at the bottom of the main body  3 . 
     Below, each configuration will be explained in detail. 
     &lt;Sample&gt; 
     A sample is a biological sample mainly contained in a vial, a blood bag, and the like. The volume of the vial, the bag, and the like, is, for example, 25 ml, 50 ml, and 100 ml. The freezing transport container  1  contains 10 or about 10 of the vials, the bags, and the like. 
     &lt;Main Body&gt; 
     The main body  3  has a heat-insulating structure, the opening  3   a  at the upper end, and a bottomed cylindrical shape as shown in  FIGS. 1 to 3 . The diameter of the opening  3   a  at the upper end and the diameter of the bottom of the main body  3  are the same. The main body  3  preferably has a vacuum double structure made of stainless steel. 
     An example of the external dimensions of the main body  3  is as follows. 
     External dimensions: φ200×H 300 mm 
     Opening and bottom: φ189 mm 
     &lt;Lid&gt; 
     The lid  5  is attached on the opening  3   a  of the main body  3  so as to be openable and closable. Further, as shown in  FIG. 1 , the lid body  5  has a cylindrical portion  9  having the same diameter as that of the opening  3   a.  The cylindrical portion  9  is inserted into the opening  3   a  of the main body  3 . The cylindrical portion  9  is formed by, for example, a heat-insulating material, such as polyurethane foam and polystyrene foam to prevent heat from entering through the opening  3   a.    
     &lt;Liquid Nitrogen Absorber Case&gt; 
     As shown in  FIG. 4 , the liquid nitrogen absorber case  7  includes a bottomed cylindrical case portion  11  and a liquid nitrogen absorber  13  replaceably installed inside the case portion  11 . The liquid nitrogen absorber case  7  is removably installed at the bottom of the main body  3 . 
     The liquid nitrogen absorber  13  is formed of a plurality of circular sheets. As shown in  FIGS. 4 and 5 , the circular sheets are arranged so as to be stacked on the bottom of the case portion  11 . 
     The liquid nitrogen absorber  13  is, for example, made of polypropylene, and has a diameter of φ180 mm, and a thickness of 50 mm when the plurality of circular sheets are stacked. 
     The liquid nitrogen absorber  13  is provided with a plurality of holes  15  in order to increase the speed at which liquid nitrogen is immersed therein (see  FIG. 5 ). Further, the plurality of holes  15  can be directly inserted with a vial-shaped sample, and also function as a sample insertion hole. 
     The shape of the hole  15  is not limited to a circular shape when the sample or the like is a vial, and may be, for example, a rectangular shape into which a bag-shaped sample  16  is inserted, as shown in  FIG. 6 . 
     When the hole  15  provided in the liquid nitrogen absorber  13  functions as a sample insertion hole, the liquid nitrogen absorber case  7  is preferably provided with a fixing plate  19  described later and shown in  FIGS. 4 and 5 . The fixing plate  19  is provided with an opening  17  having the same shape as that of the hole  15  provided in the liquid nitrogen absorber  13  at a position corresponding to the hole  15  provided in the liquid nitrogen absorber  13 . 
     The fixing plate  19  is placed on the upper surface of the liquid nitrogen absorber  13 . The fixing plate  19  is fixed to the case portion  11  by a fixing screw  23  and a spacer  21  provided so as to penetrate the stacked liquid nitrogen absorber  13  in the thickness direction. As a result, the liquid nitrogen absorber  13  formed by stacking a plurality of sheets is fixed inside the case portion  11 . A method for fixing the liquid nitrogen absorber  13  using the spacer  21  and the fixing plate  19  will be described in more detail as follows. 
     The spacer  21  is a thin cylindrical metal fitting, and is threaded inside. A screw hole corresponding to the spacer  21  is formed at the bottom of the case portion  11 . First, the fixing screw  23  is screwed into the spacer  21  from the lower surface side of the bottom of the case portion  11 . As a result, the spacer  21  is erected on the bottom of the case portion  11 . Next, the liquid nitrogen absorber  13  made of the plurality of sheets is placed in the case portion  11 . Since the liquid nitrogen absorber  13  has a spacer insertion hole formed in a portion corresponding to the spacer  21 , the liquid nitrogen absorber  13  is placed so that the spacer is inserted into the spacer insertion hole. After placing, the fixing plate  19  is arranged on the liquid nitrogen absorber  13 , and the fixing screw  23  is screwed into the spacer  21  from the upper surface side of the fixing plate  19 . Thereby, the liquid nitrogen absorber  13  can be attached into the case portion  11  by the spacer  21  and the fixing plate  19 . By disposing the fixing plate  19 , the liquid nitrogen absorber  13  is sandwiched between the bottom of the case portion  11  and the fixing plate  19  and does not fall off from the case portion  11 . 
     When replacing the liquid nitrogen absorber  13 , the liquid nitrogen absorber case  7  may be taken out from the main body  3  and the fixing plate  19  may be removed. 
     In addition to the insertion holes for the fixing screw  23 , the fixing plate  19  is provided with a large number of passage holes  25  through which liquid nitrogen passes when the liquid nitrogen absorber  13  is impregnated with the liquid nitrogen. 
     Further, as described above, when the hole  15  provided in the liquid nitrogen absorber  13  functions as a sample insertion hole, the fixing plate  19  is provided with an opening  17 . The opening  17  is provided at a position corresponding to the hole  15  provided in the liquid nitrogen absorber  13 . For example, a sample such as a vial can be inserted into the opening  17 . 
     The fixing plate  19  is formed by a metal heat conductor having high thermal conductivity such as aluminum, and copper, similar to the case portion  11  described later. 
     As shown in  FIG. 4 , the case portion  11  has a bottom portion and a side wall portion  27  provided upright from the periphery of the bottom portion. The side wall portion  27  is preferably arranged so that the outer peripheral surface thereof is in contact with the inner peripheral wall of the main body  3 . That is, it is preferable that there be no space between the inner peripheral wall of the main body  3  and the side wall portion  27  of the case portion  11 . As a result, a wide sample storage space can be secured. Furthermore, since there is no space, for example, an air layer, the heat-insulation efficiency can be improved. 
     The case portion  11  having the side wall portion  27  and the bottom portion is formed of a heat conductor, for example, metal having high thermal conductivity, such as aluminum and copper. By using a metal having high thermal conductivity, the cold heat of liquid nitrogen can be transferred to the upper part of the container faster and cool the upper part of the container. When the main body  3  is made of stainless steel, the case portion  11  is more preferably made of aluminum, which is less likely to rust. 
     An example of the dimensions of the case portion  11  is φ183 mm×H 200 mm. The thickness of the case portion is 0.5 mm, and the inner diameter of the side wall portion  27  is φ182 mm. 
     Although the description above illustrates the case in which the bottom of the case portion  11  is circular, the shape is not limited to a circular shape, and a shape such as a quadrangle or a polygon can be selected according to the application and the shape of the main body  3 . 
     The case portion  11  has a function of transmitting the cold heat of the liquid nitrogen absorber  13  and effectively cooling the sample contained therein. When the case portion  11  having such functions comes into contact with the cylindrical portion  9  made of the heat-insulating material in the lid  5 , the heat of the heat-insulating material itself is transferred to the inside of the container. Therefore, it is preferable that the case portion  11  and the cylindrical portion  9  not come into contact with each other, and it is preferable to set a gap of 2 to 3 mm between them. 
     When the side wall portion  27  of the case portion  11  has a height such that the upper end thereof is the same as the upper end of the inner wall surface of the main body  3 , the cold heat of liquid nitrogen can be efficiently transmitted to the upper portion of the main body  3 . Therefore, the inside of the main body  3  can be kept at a lower temperature. 
     On the other hand, as described above, the amount of evaporation loss of liquid nitrogen increases because the heat from the opening  3   a  is easily transferred to the inside of the container. 
     Therefore, it is preferable that the height of the side wall portion of the case portion  11  satisfy the following relationship. 
     (Distance from the upper end of the liquid nitrogen absorber  13  to the bottom of the cylindrical portion  9  of lid  5 ):(Height of the side wall portion  27 ) is preferably 100:0 to 95, and more preferably 100:70 to 90. 
     When (Distance from the upper end of the liquid nitrogen absorber  13  to the bottom of the cylindrical portion  9  of lid  5 ):(Height of the side wall portion  27 ) is 100:0, as shown in  FIG. 7 , the height of the side wall portion  27  of the case portion  11  is the same as the height of the liquid nitrogen absorber  13 . When the height of the storage portion in the main body  3  is low, even if the height of the side wall portion  27  of the case portion  11  is the same as the height of the liquid nitrogen absorber  13 , the storage space (holes  15  provided in the liquid nitrogen absorber  13 ) is sufficiently cooled by vaporized nitrogen. When the sample is inserted into the hole  15  of the liquid nitrogen absorber  13 , the height of the side wall portion  27  of the case portion  11  may be the same as the height of the liquid nitrogen absorber  13 . 
     In order to secure a wide space, it is preferable that the outer diameter of the side wall portion  27  of the case portion  11  be substantially the same as the inner diameter of the main body  3 . 
     Further, when it is desired to rapidly cool the inside of the freezing transport container  1  or lower the temperature, fins may be provided on the inner wall of the side wall portion  27  in order to improve the heat-transfer performance. 
     The liquid nitrogen absorber case  7  is installed removably in the main body  3 , and it is preferable that the liquid nitrogen absorber case  7  can be taken out easily. For example, it is preferable to use an annular case fixture  29  which is detachably attached in the vicinity of the opening  3   a  of the main body  3  (see  FIGS. 1 and 3 ). 
     The outer diameter of the case fixture  29  is preferably slightly larger than the inner diameter of the opening  3   a  of the main body  3 . Further, the case fixture  29  is preferably formed of a heat-insulating and flexible member such as polyurethane foam and polystyrene foam. As shown in  FIG. 1 , the case fixture  29  is attached in the vicinity of the opening  3   a  of the main body  3  in a state in which the liquid nitrogen absorber case  7  is arranged inside the main body  3 . 
     Since the outer diameter of the case fixture  29  is slightly larger than the inner diameter of the main body  3 , the case fixture  29  is detachably attached to the main body  3  in a compressed state. In this way, the case fixture  29  is press-fitted into the main body  3  and is arranged in close contact with the inner wall of the main body  3  at the upper part of the liquid nitrogen absorber case  7 . Accordingly, even if the freezing transport container  1  is tilted, the liquid nitrogen absorber case  7  will not come out. 
     On the other hand, when the liquid nitrogen absorber case  7  is taken out in order to exchange the liquid nitrogen absorber  13  or the like, the case fixture  29  may be slightly bent and removed. 
     As described above, in the freezing transport container  1  of the present embodiment, the liquid nitrogen absorber case  7  can be taken out and the liquid nitrogen absorber  13  can be easily replaced. Therefore, if the liquid nitrogen absorber  13  is deteriorated or contaminated, it can be replaced. 
     When the height of the side wall portion  27  of the case portion  11  is higher than the height of the liquid nitrogen absorber  13 , since the side wall portion  27  is along the inner wall of the main body  3 , and the liquid nitrogen absorber  13  is arranged only at the bottom of the portion  11 , the internal space is wide and a large sample such as a bag can be accommodated, which makes it possible to transport a large sample, which has been difficult in the past. 
     For example, a 50 ml bag-shaped sample requires a space of 95 mm (length)×85 mm (width)×10 mm (thickness). The diameter of the opening of a part of the conventional general dry shipper is narrower than the outer diameter. For example, the opening is designed to have a diameter of 50 mm to 70 mm. Therefore, a bag-shaped sample cannot be stored in a dry shipper having such dimensions. Alternatively, in order to store the bag-shaped sample in a dry shipper of which the opening diameter is smaller than the outer diameter, a dry shipper having a larger outer diameter must be used. Therefore, there are inconveniences such as an increase in the amount of liquid nitrogen used. 
     On the other hand, in the present embodiment, since the diameter of the opening and the diameter of the bottom of the main body  3  are the same, the opening  3   a  is φ189 mm, and the inner diameter of the side wall portion  27  is φ182 mm, it is possible to store the samples in the mode shown in  FIG. 6 . 
     Further, when the height of the side wall portion  27  of the case portion  11  is larger than the height of the liquid nitrogen absorber  13 , it is possible to maintain a low temperature without narrowing the content volume of the upper part of the container storage space in which the temperature does not easily drop due to the heat-transfer from the lid  5  and the influence of the outside air temperature. 
       FIG. 8  shows the temperature inside the freezing transport container  1  of the present embodiment. A temperature of about −150° C. can be realized even in the upper part of the side wall portion  27 . 
     That is, in a conventional freezing transport container, an impregnating material (liquid nitrogen absorber) is arranged on the bottom portion and the inner peripheral wall of the main body  3  which is a heat-insulating container. On the other hand, the freezing transport container  1  of the present embodiment includes the bottomed tubular case portion  11  having a side wall portion  27 , and the liquid nitrogen absorber  13  is installed in the case portion  11 . In particular, when the height of the side wall portion  27  is higher than the height of the liquid nitrogen absorber  13 , the sample storage space is kept large in volume and kept at a low temperature. 
     When the liquid nitrogen absorber  13  is installed on the bottom of the main body  3  having the same shape as that of the liquid nitrogen adsorber case  7  without providing the liquid nitrogen absorber case  7  in the main body  3 , that is, in a conventional freezing transport container, the cold heat of the liquid nitrogen absorber  13  is transmitted to the inner wall of the main body  3  which is formed by stainless steel. However, since stainless steel has a low thermal conductivity, the upper part does not easily cool. Accordingly, as shown in  FIG. 9 , the temperature at the upper part is only about −30° C. From this result, a great effect can be expected when the case portion  11  includes the side wall portion  27  having a height larger than the height of the liquid nitrogen absorber  13 . 
     Since the freezing transport container shown in  FIG. 9  does not have the liquid nitrogen absorber case  7 , the case fixture  29  is unnecessary, and the case fixture  29  is also not provided. 
     In the case of the freezing transport container  1  shown in  FIG. 8 , it took about 30 minutes for the temperature inside the main body  3  to reach −150° C. or lower after the liquid nitrogen absorber case  7  had been installed in the main body  3 , and the temperature inside the main body  3  could be maintained at −150° C. or lower for about 300 minutes. 
     In the embodiment above, an example in which the main body  3  of the freezing transport container  1  has a cylindrical shape has been described. In this case, the liquid nitrogen absorber case  7  installed in the main body  3  also has a similar cylindrical shape. 
     However, the main body  3  of the freezing transport container  1  is not limited to a cylindrical shape, and may be, for example, a rectangular tubular shape. In this case, it is preferable that the liquid nitrogen absorber case  7  installed in the main body  3  also have the same rectangular tubular shape. 
     Further, in the embodiment above, liquid nitrogen is taken as an example as the cryogenic liquefied gas. However, the cryogenic liquefied gas used in the present invention is not limited to liquid nitrogen, and as long as a suitable absorbent material is used, a liquefied gas of an inert gas such as liquid helium and liquid argon can also be used. 
     EXPLANATION OF REFERENCE NUMERAL 
       1  freezing transport container 
       3  main body 
       3   a  opening 
       5  lid 
       7  liquid nitrogen absorber case 
       9  cylindrical portion 
       11  case portion 
       13  liquid nitrogen absorber 
       15  hole 
       16  bag-shaped sample 
       17  opening 
       19  fixing plate 
       21  spacer 
       23  fixing screw 
       25  passing hole 
       27  side wall portion 
       29  case fixture