Abstract:
An object of the invention is to provide a multigas incubator capable of shortening humidity-returning time after closing its door. The incubator comprises an adiabatic box main body having an opening on a front face thereof, an adiabatic door mounted on the adiabatic box main body in an openable and closable manner, a transparent inner door for openably closing the opening, and an incubation room surrounded by the inner door and the adiabatic box main body for incubating samples such as cells, microbes and the like. The adiabatic box main body comprises an outer box made of a metal, an inner box made of a metal, a heat insulating material arranged inside the outer box between the outer and inner boxes, and an air layer arranged more inside than the heat insulating material. Gases supplied for controlling concentrations of gases in the incubation room are jetted into humidification water.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to a carbon dioxide gas (CO 2 ) incubator or a multigas incubator as an incubator for incubating cultures (samples) such as cells, microbes and the like.  
         [0002]     The incubator maintains a temperature and a CO 2  concentration constant therein (in incubation room) and keeps its inside in a sterile condition to incubate cultures (samples) such as cells or microbes as incubation targets. Therefore, the inside of the incubator must be periodically processed by sterilization treatment. There has been a multigas incubator provided with a heater and its controller for adjusting the temperature in the incubation room (storing room), gas supply means for supplying and controlling supply gases such as CO 2 , O 2  and the like for controlling concentrations of gases, and a humidifying tray for adjusting the humidity, respectively for the purpose of incubating samples in the incubation room.  
         [0003]     On the other hand, as disclosed in Japanese Patent Application Laid Open Nos. 31,462/1995 and 166,536/2000, there have been incubating devices each comprise an outer box provided on its inner side with a heat insulating material for uniformly and effectively heating the inside of an inner box to improve its temperature-returning characteristics, the inner box arranged inside the outer box with a space more inside than the heat insulating material, and a heating device secured in the space in contact with the inner box for heating the inside thereof. The space described above serves to form an air layer (air jacket) provided for the thermal insulation between the incubation room of the incubator and its outside and promotion of heat transfer by natural convection. As shown in the latter patent literature, particularly, a humidifying tray is arranged at the bottom of the incubation room for storing humidification water for controlling the humidity in the incubation room.  
         [0004]     On the other hand, a multigas incubator accommodates therein important and valuable cells, microbes or the like to be incubated so that variations in humidity in the incubation room cannot be avoided by the ambient air entering the incubator when an inner door is opened. Taking account of the fact that variations in humidity adversely affect samples such as cells and the like to be incubated, it is needed to shorten the time as much as possible, which is required to return a desired humidity after the inner door is once opened and then closed (that is, humidity-returning time). In the case incubating human cells for ectosomatic fertilization or animal fertile eggs as samples, particularly, these samples are likely to be remarkably affected by humidity so that extra precautions are required. In the incubators for treating such samples, the concentration of O 2  is frequently set and kept at approximately 5%, and dried N 2  gas is supplied into an incubation room after closing the door in order to control the concentration of O 2 . Consequently, the humidity-returning time would be adversely prolonged by such a supply of the dried gas.  
       SUMMARY OF THE INVENTION  
       [0005]     It is an object of the invention to provide an incubator such as a multigas incubator capable of shortening humidity-returning time after closing its inner door. In addition thereto, it is an object of the invention to improve evaporation faculty of humidification water for controlling the humidity in the incubation room.  
         [0006]     The incubator ( 1 ) according to the invention comprises an adiabatic box main body ( 2 ) having an opening ( 2 A) on a front face thereof, an adiabatic door ( 7 ) mounted on the adiabatic box main body ( 2 ) in an openable and closable manner, a transparent inner door ( 3 ) for openably closing the opening ( 2 A), and an incubation room ( 4 ) surrounded by the inner door ( 3 ) and the adiabatic box main body ( 2 ) for incubating samples such as cells, microbes and the like, the adiabatic box main body ( 2 ) comprising an outer box ( 21 ) made of a metal, an inner box ( 22 ) made of a metal, a heat insulating material ( 24 ) arranged inside the outer box between the outer and inner boxes ( 21 ,  22 ), and an air layer ( 25 ) arranged more inside than the heat insulating material ( 24 ), and gas supplied for controlling gas concentration in the incubation room ( 4 ) is jetted into humidification water ( 16 ).  
         [0007]     According to this invention, the gases supplied for controlling the gas concentration in the incubation room ( 4 ) are jetted into the humidification water ( 16 ) so that the supplied gases absorb moisture to be humidified, while rising in the humidification water, thereby enabling the humidified gases to be circulated in the incubation room to contribute to the improvement of humidification faculty of the humidifying tray ( 15 ) in addition to the supply of gases.  
         [0008]     Moreover, the incubator ( 1 ) according to the present invention further comprises a humidifying tray ( 15 ) for storing humidification water ( 16 ) for controlling the humidity in the incubation room ( 4 ), and gas supply means ( 17 ) for supplying gas for controlling the gas concentration in the incubation room ( 4 ), and a gas outlet port ( 17 A) of the gas supply means is immersed in the humidification water ( 16 ) in the humidifying tray ( 15 ).  
         [0009]     According to this invention, as a gas outlet port ( 17 A) of the gas supply means for supplying gases for controlling the concentrations of the gases in the incubation room ( 4 ) is immersed in the humidification water ( 16 ) in the humidifying tray ( 15 ) for controlling the humidity in the incubation room ( 4 ), the gases supplied from the gas outlet port ( 17 A) can be jetted into the humidification water ( 16 ) in the humidifying tray, making it possible to humidify the supply gases and to circulate them into the incubation room ( 4 ).  
         [0010]     Further, the incubator ( 1 ) according to the present invention further comprises a support ( 18 ) for supporting the gas outlet port ( 17 A) of the gas supply means ( 17 ).  
         [0011]     According to this invention, as there is provided the support ( 18 ) for supporting the gas outlet port ( 17 A) of the gas supply means ( 17 ), the gas outlet port ( 17 A) of the gas supply means can be supported by the support ( 18 ) so as to be immersed in the humidification water ( 16 ) in the humidifying tray ( 15 ).  
         [0012]     In the incubator ( 1 ) of the present invention, moreover, the support ( 18 ) comprises restraining means ( 18 A) for restraining rising of the gas.  
         [0013]     According to this invention, as the support ( 18 ) comprises restraining means ( 18 A) for restraining rising of the gases, a space can be formed between the restraining means ( 18 A) and the water surface of the humidification water so that the evaporation of the humidification water is promoted to improve the evaporation faculty by the gases accumulated in the space.  
         [0014]     Furthermore, the incubator ( 1 ) of the present invention comprises an adiabatic box main body ( 2 ) having an opening ( 2 A) on a front face thereof, an adiabatic door ( 7 ) mounted on the adiabatic box main body in an openable and closable manner, a transparent inner door ( 3 ) for openably closing the opening, an incubation room ( 4 ) surrounded by the inner door and the adiabatic box main body for incubating samples such as cells, microbes and the like, a humidifying tray ( 15 ) for storing humidification water ( 16 ) for controlling the humidity in the incubation room, gas supply means ( 17 ) for supplying gas for controlling gas concentration in the incubation room, and a duct ( 11 ) and a circulation blower ( 14 ) for causing forced convection of air in the incubation room, and gas supplied for controlling the gas concentration in the incubation room ( 4 ) is jetted into the humidification water ( 16 ).  
         [0015]     According to this invention, the incubator ( 1 ) of the present invention comprises an adiabatic box main body ( 2 ) having an opening ( 2 A) on a front face thereof, an adiabatic door ( 7 ) mounted on the adiabatic box main body in an openable and closable manner, a transparent inner door ( 3 ) for openably closing the opening, an incubation room ( 4 ) surrounded by the inner door and the adiabatic box main body for incubating samples such as cells, microbes and the like, a humidifying tray ( 15 ) for storing a humidification water ( 16 ) for controlling the humidity in the incubation room, gas supply means ( 17 ) for supplying gases for controlling concentrations of gases in the incubation room, and a duct ( 11 ) and a circulation blower ( 14 ) for causing forced convection of air in the incubation room, and gases supplied for controlling concentrations of the gases in the incubation room ( 4 ) are jetted into the humidification water ( 16 ). Therefore, the gases supplied from the gas supply means ( 17 ) absorb moisture to be humidified, while naturally rising in the humidification water ( 16 ) in the humidifying tray ( 15 ) so that the humidified gases can be guided into the incubation room ( 4 ) by the circulation blower ( 14 ) and the duct ( 11 ), thereby promoting the evaporation of the humidification water ( 16 ) by the supplied gases to contribute to the improvement of evaporation faculty of the humidifying tray ( 15 ) in addition to the supply of gases.  
         [0016]     In the incubator ( 1 ) of the present invention, further, a gas outlet port ( 17 A) of the gas supply means is immersed in the humidification water ( 16 ) in the humidifying tray.  
         [0017]     According to this invention, the gas outlet port ( 17 A) of the gas supply means for supplying gases for controlling the concentrations of the gases in the incubation room ( 4 ) is immersed in the humidification water ( 16 ) in the humidifying tray ( 15 ) stored for controlling the humidity in the incubation room ( 4 ). Therefore, the gases (O 2  and N 2 ) supplied from the gas outlet port ( 17 A) can be jetted into the humidification water ( 16 ) in the humidifying tray so that the supplied gases can be humidified and circulated into the incubation room ( 4 ).  
         [0018]     In the incubator ( 1 ) of the present invention, further, the humidifying tray ( 15 ) is arranged in the duct ( 11 ) and at the bottom of the incubation room ( 4 ).  
         [0019]     According to this invention, the humidifying tray ( 15 ) is arranged in the duct ( 11 ) and at the bottom of the incubation room ( 4 ) so that the humidified gases can be jetted with high efficiency into the air passage K formed by the circulation blower ( 14 ) and the duct ( 11 ) and leading to the incubation room ( 4 ).  
         [0020]     The incubator ( 1 ) according to the present invention further comprises a support ( 8 ) for supporting the gas outlet port ( 17 A) of the gas supply means.  
         [0021]     According to this invention, there is provided the support ( 8 ) for supporting the gas outlet port ( 17 A) of the gas supply means so that the gas outlet port ( 17 A) of the gas supply means can be supported by the support ( 18 ) so as to be immersed in the humidification water ( 16 ) in the humidifying tray ( 15 ).  
         [0022]     In the incubator ( 1 ) according to the present invention, the support ( 18 ) forms a passage in the same direction as the air flowing direction formed by the duct ( 11 ).  
         [0023]     According to the invention, the support ( 18 ) forms a passage in the same direction as the air flowing direction formed by the duct ( 11 ) so that the humidified gases can be conducted with high efficiency in the air flowing direction formed by the circulation blower ( 14 ) and the duct ( 11 ) and leading to the incubation room ( 4 ). Also, the spacing between the support ( 18 ) and the water surface can be less than the spacing between the water surface and the duct ( 11 ) so that the air velocity in the space formed by the support ( 18 ) and the water surface is higher than the velocity of the air flow in the air passage K, thereby enabling the evaporation faculty of the humidification water to be improved by the increase in the velocity of the air flow.  
         [0024]     The incubator ( 1 ) comprises an adiabatic box main body ( 2 ) having an opening on its front face, an adiabatic door ( 7 ) mounted on the adiabatic box main body in an openable and closable manner, a transparent inner door ( 3 ) for openably closing the opening, an incubation room ( 4 ) surrounded by the inner door ( 3 ) and the adiabatic box main body ( 2 ) for incubating samples such as cells, microbes and the like, a duct ( 11 ) and a circulation blower ( 14 ) for causing forced convection of air in the incubation room, a humidifying tray ( 15 ) arranged in the duct ( 11 ) and at the bottom of the incubation room ( 4 ) for storing humidification water ( 16 ) for controlling the humidity in the incubation room, and gas supply means ( 17 ) for supplying gas for controlling gas concentration in the incubation room, the adiabatic box main body comprising an outer box ( 21 ) made of a metal, an inner box ( 22 ) made of a metal, a heat insulating material ( 24 ) arranged inside the outer box between the outer and inner boxes, and an air layer ( 25 ) arranged more inside than the heat insulating material, and the incubator further comprises a support ( 18 ) for immersing the gas outlet port ( 17 A) of the gas supply means ( 17 ) in the humidification water ( 16 ) in the humidifying tray ( 15 ).  
         [0025]     According to the invention, the incubator ( 1 ) comprises an adiabatic box main body ( 2 ) having an opening on its front face, an adiabatic door ( 7 ) mounted on the adiabatic box main body in an openable and closable manner, a transparent inner door ( 3 ) for openably closing the opening, an incubation room ( 4 ) surrounded by the inner door ( 3 ) and the adiabatic box main body ( 2 ) for incubating samples such as cells, microbes and the like, a duct ( 11 ) and a circulation blower ( 14 ) for causing forced convection of air in the incubation room, a humidifying tray ( 15 ) arranged in the duct ( 11 ) and at the bottom of the incubation room ( 4 ) for storing humidification water ( 16 ) for controlling the humidity in the incubation room, and gas supply means ( 17 ) for supplying gas for controlling gas concentration in the incubation room, the adiabatic box main body comprising an outer box ( 21 ) made of a metal, an inner box ( 22 ) made of a metal, a heat insulating material ( 24 ) arranged inside the outer box between the outer and inner boxes, and an air layer ( 25 ) arranged more inside than the heat insulating material, and the incubator further comprises a support ( 18 ) for immersing the gas outlet port ( 17 A) of the gas supply means ( 17 ) in the humidification water ( 16 ) in the humidifying tray ( 15 ). Therefore, the gas outlet port ( 17 A) is supported by the support ( 18 ) so as to be immersed in the humidification water ( 16 ) in the humidifying tray ( 15 ) so that the gases jetted from the gas outlet port ( 17 A) absorb the moisture to be humidified, while naturally raising in the humidification water ( 16 ), thereby enabling the humidified gases to be guided into the incubation room ( 4 ) by the circulation blower ( 14 ) and the duct ( 11 ) to improve the humidification faculty in addition to the supply of humidified gases. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]      FIG. 1  is a perspective view of the incubator with its adiabatic door opened according to the present invention;  
         [0027]      FIG. 2  is a sectional view of the incubator according to the present invention viewed from the right for explaining the air circulation mainly through the incubation room and the duct;  
         [0028]      FIG. 3  is a sectional view of the incubator according to the present invention viewed from the right mainly illustrating the incubation room and the humidifying tray;  
         [0029]      FIG. 4  is a perspective view of the incubation room to illustrate the humidifying tray and the support according to the present invention; and  
         [0030]      FIG. 5  is a perspective view illustrating the support in detail according to the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0031]     Embodiments of the present invention will be described in detail with reference to the accompanying drawings hereinafter.  
         [0032]     (Embodiment 1)  
         [0033]     A multigas incubator  1  as an incubator of the first embodiment of the present invention comprises left hand opening doors (an outer and an inner door in more detail) and smaller doors as biparting doors as shown in FIGS.  1  to  3 . An incubation room  4  is formed by a space surrounded by an adiabatic box main body  2  having an opening  2 A in its front and a transparent door  3  as the inner door closing the opening  2 A in an openable and closable manner. The transparent door  3  is supported at its left end by the adiabatic box main body  2  by means of hinges in an openable and closable manner so that when closed, the opening  2 A is air-tightly closed with a gasket  2 B provided at the opening of the incubation room  4 . The adiabatic box main body  2  is provided with the seal member or gasket  2 B along the periphery of the opening  2 A of the adiabatic box main body  2  to seal the transparent inner door  3  and the main body  2 .  
         [0034]     The inside of the incubation room  4  is divided into upper and lower portions by a plurality of shelves  5  (into five portions by four shelves  5  in the illustrated embodiment). As the incubator  1  in the embodiment is a multigas incubator, the concentration of O 2  is frequently set and kept at a value of the order of 5%. In this case, the concentration of O 2  may be controlled by supplying an amount of dried N 2  gas into the incubation room after the doors are closed. For this purpose, in order to prevent the ambient air from entering the entire incubation room  4  divided in the plurality of portions, even if the inner door  3  is opened, the smaller doors  6 A and  6 B as the biparting doors inside the inner door  3  are divided into a plurality (five pairs in the illustrated embodiment) of parts correspondingly to the number of the portions of the incubation room  4  divided by the shelves  5 . Reference numeral  7  denotes the adiabatic door as the outer door supported on the adiabatic box main body  2  through hinges in an openable and closable manner for preventing the heat from entering through the opening  2 A of the incubation room. The adiabatic door  7  is provided on its inner periphery with a gasket  8  having magnets therein.  
         [0035]     Arranged in the incubation room  4  is a duct  11  consisting of a rear face duct  11 A and a bottom face duet  11 B respectively spaced from the rear wall and the bottom wall of the adiabatic box main body  2  to form the air passage K, respectively. The rear face duct  11 A is formed in its upper portion with suction openings  12  from which the air in the incubation room  4  is sucked into the duct  11  and exhausted through exhaust openings  13  provided in the bottom face duct  11 B at its front end and side faces to forcedly circulate the air in the incubation room  4 . A circulation blower  14  for the forced circulation of the air in the incubation room is arranged in the duct  11  (in the upper portion of the duct  11  in the illustrated embodiment). The blower  14  comprises a fan, a motor and a shaft. The motor is located in a machine house  19  on the outer rear face of the incubation room  4  described later, while the shaft extends from the motor in the machine house  19  through the rear face of the main body  2  into the air passage K and is connected to the fan.  
         [0036]     A humidifying tray  15  for storing water for humidification (that is, humidification water)  16  is arranged at the bottom of the incubation room  4  and in the duct  11 . The humidification water  16  in the humidifying tray  15  is heated to be evaporated by heating means (not shown) arranged outside the bottom surface of an inner box  22  made of a metal, for example, stainless steel. By arranging the humidifying tray  15  in the duct  11  and at the bottom of the incubation room  4 , it becomes possible to blow the humidified gas with high efficiency into the air passage K formed by the circulation blower  14  and the duct  11  and leading to the incubation room  4 .  
         [0037]     On the rear face of an outer box  21  of the adiabatic box main body  2  is formed a machine house  19  for arranging a motor for driving the circulation blower  14 , gas supply means  17  for supplying gases such as N 2 , O 2  and the like to the incubation room  4 , and electrical equipment such as a control panel and the like (not shown).  
         [0038]     The gas supply means  17  comprises a gas supply tube  17 A, an opening and closing valve  17 B, a filter  17 C and the like. The leading end portion of the gas supply tube  17 A is supported by a support  18  such that the leading end portion is in the humidification water  16  in the humidifying tray  15 . The support  18  consists of a main body  18 A having a left and a right side face and an upper face to from a U-shape in cross-section and legs  18 B for installing the main body  18 A. The upper surface of the main body  18 A provides restraining means for restraining the rising of the gas.  
         [0039]     By providing the support  18  for supporting the gas outlet port  17 A of the gas supply means  17 , the gas outlet port  17 A of the gas supply means can be supported to be immersed in the humidification water  16  in the humidifying tray  15 . As the support  18  includes the restraining means  18 A for restraining the rising of the gas, moreover, when the height h 1  of the support  18  is set to a value substantially equal to the height h 2  of the humidifying tray  15 , it is possible to form a space between the restraining means  18 A and the water surface of the humidification water. The evaporation of the humidification water will be promoted by the gas accumulated in the space, thereby improving the evaporation faculty. In order to observe the improvement of the evaporation faculty and the promotion of the evaporation, the times required for returning to a targeted humidity after the smaller doors are opened for a constant period of time were measured with the cases that the gas outlet port  17 A of the gas supply means  17  is immersed in the humidification water  16  according to the present invention and that the gas is blown into the incubation room  4  or the air passage K in the conventional manner. The former according to the present invention required 12 minutes, while the later in the conventional manner took 36 minutes. It is apparent, therefore, that the evaporation faculty is improved by immersing the gas outlet port in the humidification water  16  according to the present invention.  
         [0040]     As described above, the outlet port  17 A of the gas supply means for supplying the gases for controlling the concentration of the gases in the incubation room  4  is immersed in the humidification water  16  in the humidifying tray  15 , which is stored therein for the purpose of controlling the humidity in the incubation room  4  according to the invention. Accordingly, the gases (O 2  and N 2 ) supplied through the gas outlet port  17 A can be jetted into the humidification water  16  in the humidifying tray so that the supply gases can be humidified and circulated in the incubation room  4 .  
         [0041]     Referring to  FIGS. 2 and 3 , the adiabatic box main body  2  comprises the outer box  21  made of a metal, the inner box  22  made of stainless steel, a heat insulating material  24  arranged on the inner side of the outer box  21  between the outer box  21  and the inner box  22 , and an air layer (a so-called air jacket)  25  arranged more inside than the heat insulating material  24 . Heaters (not shown) for heating the incubation room are arranged on both the left and right side faces, the upper face and the rear face of the inner box  22  forming the incubation room  4 .  
         [0042]     By providing the support  18  for supporting gas outlet port  17 A of the gas supply means  17  to be immersed in the humidification water  16  in the humidifying tray  15  in the first embodiment, the gas outlet port  17 A is supported to be immersed in the humidification water  16  in the humidifying tray  15  so that the gases jetted from the gas outlet port  17 A absorb the moisture to be humidified, while rising naturally in the humidification water  16 . Accordingly, the humidified gases can be guided into the incubation room  4  by means of the circulation blower  14  and the duct  11  so that in addition to the supply of the humidified gases the humidification faculty can be improved, thereby enabling shortening of the returning time to the targeted humidity after closing of the inner door (smaller door  6 A or  6 B in the embodiment).  
         [0043]     (Embodiment 2)  
         [0044]     The second embodiment of the present invention will be explained with reference to FIGS.  3  to  5  hereinafter. A support  18  in the second embodiment of the present invention is so arranged that opposite open ends of the support  18  are arranged in a line in the same direction as the air flowing direction in the air passage K formed by the bottom face duct  11 B.  
         [0045]     According to the support  18  in the second embodiment, it forms a passage in the same direction as the air flowing direction formed by the duct  11  so that the humidified gases are conducted with high efficiency in the air flowing direction formed by the circulation blower  14  and the duct  11  leading to the incubation room  4 . Accordingly, the spacing between the support  18  and the water surface can be less than the spacing between the water surface and the duct  11  so that the air flow velocity in the space formed by the support  18  and the water surface becomes faster than the air flow velocity in the air passage K, with the result that the evaporation faculty of the humidification water can be improved by the increase in the air flow velocity.