JP2002325565A - Lyophilized material, method and device for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for producing lyophilized materials, capable of efficiently removing a large amount of carbon dioxide gas generated by the sublimation of dry ice from a cooled and frozen treated materials and water content from the frozen materials even by using the dry ice as a cooling medium, capable of preventing the adhesion among the treated materials each other by drying the treated materials while rotating them and shortening the drying time of the frozen materials, and also capable of obtaining a high quality lyophilized materials, since it is possible to uniformly heat the frozen materials, and the lyophilized materials obtained by the above method. SOLUTION: The method and device for producing a lyophilized materials is provided by housing a container 4 for the treated materials, having an air- ventilating property and for housing the frozen treated materials cooled by the dry ice, in a rotary cage 3 in a lyophilizing device main body 1, heating the treated materials by a heating device 6 under a vacuum condition, and sublimating the dry ice and water content contained in the treated materials to obtain the lyophilized materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lyophilized product obtained by removing a refrigerant and moisture from a frozen object which has been cooled by a refrigerant such as dry ice or the like, and a method and an apparatus for producing the same.

[0002]

2. Description of the Related Art There has been proposed a method of removing dry ice and ice from an object cooled and dried with dry ice to obtain a freeze-dried product. For example, Patent No. 3005
No. 657 proposes a method in which dry ice and raw biological materials, drugs, foods, industrial raw materials, and the like are mixed while being pressurized, and crushed in a frozen state and freeze-dried under vacuum conditions. ing.

[0003] As described above, the object to be treated is mixed with dry ice, the gas phase is replaced with the generated carbon dioxide gas, and is frozen substantially instantaneously.
The object to be processed can be freeze-dried while maintaining the quality and properties before processing without undergoing deterioration due to oxygen, enzymes, heat, etc. by a simple apparatus and operation. The resulting freeze-dried product is an inert freeze-dried product that is not deteriorated by oxygen, heat, etc., and retains the quality, properties, etc. before processing, and can be stored, transported, used as it is, without deterioration Can be used in state.

A conventional freeze-drying apparatus used in such a method includes a plurality of multi-stage heating shelves inside a closed chamber having an exhaust manifold and an openable / closable closed door connected to an opening. After the object to be processed is installed on each shelf from the opening, and the sealed chamber is evacuated in this state,
The shelf plate is heated to freeze-dry the object to be processed, and the moisture sublimated from the object is guided to a cold trap connected to an exhaust manifold to aggregate the water and freeze-dry the object to be processed. ing.

However, in such a conventional freeze-drying apparatus, the space volume between the shelves is reduced due to the plurality of heating shelves in the closed chamber, the overall volume is reduced, and the shape and amount of the object to be processed are limited. Difficult to process in large quantities. In addition, since the object to be processed is placed in a narrow space on the shelf in the closed room, the heat transfer is uneven, and the portion near the heated surface of the object to be processed may deteriorate due to partial heating. It is difficult to equalize. When a frozen product such as a strawberry slice overlaps with a frozen product in a stacked state, the contact surfaces of a plurality of objects to be processed adhere to each other to be in an adhered state, and the surface area is reduced, and the drying efficiency may be significantly reduced. . Conventionally, a rotary pump has been used as a vacuum pump connected to the exhaust manifold.However, when an object to be processed is frozen in a mixed state with dry ice, a large amount of carbon dioxide gas sublimated from the dry ice is released. Therefore, it is difficult to reduce the pressure in the closed chamber, the vacuum drying efficiency of the object to be treated is reduced, and efficient freeze-drying is difficult.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to prepare a freeze-dried product by efficiently removing a refrigerant and moisture from a frozen object to be processed, even when dry ice is used as a refrigerant. A large amount of carbon dioxide gas generated by sublimation can be efficiently removed, and by drying while rotating the object, adhesion between the objects can be prevented, and the drying time of the frozen material can be reduced. It is an object of the present invention to provide a method and an apparatus for producing a lyophilized product capable of obtaining a high-quality lyophilized product because the frozen product can be uniformly heated, and a lyophilized product obtained thereby.

[0007]

SUMMARY OF THE INVENTION The present invention relates to the following lyophilized product, its production method and apparatus. (1) A breathable object container that holds an object to be cooled and frozen by a refrigerant is accommodated in a rotating cage in a freeze-drying apparatus, and the object to be processed is heated by a heating device under vacuum conditions. And a method for producing a freeze-dried product by sublimating moisture in a treatment object to obtain a freeze-dried product. (2) The method according to the above (1), wherein the objects to be processed are accommodated in the object container without being bonded to each other. (3) The method according to the above (1) or (2), wherein the heating device is a heating lamp. (4) The method according to any one of (1) to (3) above, wherein the refrigerant is dry ice. (5) The method according to the above (4), wherein the object to be processed is contained in a container to be processed in a state of being mixed with dry ice. (6) The method according to the above (4) or (5), wherein the freeze-drying is performed by changing the heating conditions according to the state of sublimation of the dry ice. (7) The method according to any one of the above (4) to (6), wherein the freeze-drying is performed by changing the conditions for evacuation according to the state of sublimation of the dry ice. (8) The above (1) to (3) wherein the refrigerant is liquid nitrogen.
The method according to any of the above. (9) An apparatus main body having a closed chamber, a rotating cage provided in the closed chamber so as to rotate while accommodating and rotating a gas-permeable object container accommodating the object cooled and frozen by the refrigerant. A freeze-drying device including a heating device provided in the main body so as to heat the processing object, a cold trap connected to the closed chamber and having a cooling unit, and a vacuum generator for reducing the pressure in the closed chamber through the cold trap. (10) The apparatus according to the above (9), wherein the power transmission for rotating the rotating cage is performed by a magnet coupling. (11) The device according to (9) or (10), wherein the heating device is a heating lamp. (12) The apparatus according to any one of (9) to (11), wherein the heating device is configured to change heating conditions according to a state of sublimation of the dry ice when the refrigerant contains dry ice. (13) The vacuum generator described in (9) to (1) above, wherein when the refrigerant contains dry ice, the vacuuming condition can be changed according to the state of sublimation of the dry ice.
The device according to any one of 2). (14) A freeze-dried product produced by any one of the above (1) to (8). (15) A food or pharmaceutical containing the freeze-dried product according to (14).

In the present invention, the object to be freeze-dried is an object to be subjected to ordinary freeze-drying, for example, an organic substance,
Inorganic substances and their mixtures are all covered.
In particular, substances that are easily degraded, such as organisms, organic substances, foods, drugs, biological samples, feeds, and industrial raw materials, are suitable.
Examples include substances containing an organic substance having a functional group or the like which is easily deteriorated by an enzyme or the like. These objects to be treated include those in any form, such as lump, liquid, jelly, and slurry.
It may be a crushed material, a powdery material, or the like. These are typically in the form of a water-containing substance as the object to be treated, but can be applied to a dry substance, for example, when mixed with water or a water-containing substance and homogenized.

As the refrigerant used in the present invention, any refrigerant capable of freezing the above-mentioned object can be used without limitation. Specifically, dry ice, liquid nitrogen,
Mixtures of dry ice and acetone or ethyl alcohol are examples. Among them, dry ice or liquid nitrogen is preferable, and dry ice is particularly preferable.

In the following description, a case where dry ice which can be preferably used as a refrigerant is used will be described. However, the present invention is not limited to dry ice, and other refrigerants can be used in the same manner as dry ice.

Dry ice is solidified carbon dioxide, which sublimes at −78.5 ° C. under atmospheric pressure to carbon dioxide. As such dry ice, commercially available dry ice or the like can be used. This dry ice can be easily crushed by applying pressure by a mixing and crushing apparatus, and therefore, any shape and size can be used. For example, a particle having a particle size of about 1 to 5 cm is preferable. The amount of dry ice used varies depending on the type, moisture content, properties, etc. of the object to be treated, but is preferably 0.01 to 100 parts by weight, preferably about 0.1 to 10 parts by weight, per 1 part by weight of the object to be treated. be able to.

In the present invention, the object to be processed is cooled by a refrigerant such as dry ice and the frozen material is frozen and freeze-dried in a freeze-drying apparatus. During freezing, for example, the object to be treated is mixed with dry ice, and the gas phase is replaced with generated carbon dioxide gas and can be frozen substantially instantaneously. It is preferable to mix and crush and replace the gas phase with carbon dioxide gas generated at this time to expel oxygen, and at the same time, freeze the object to be processed to produce a frozen product. In this case, the dry ice is easily crushed by the mixing and crushing device and mixed with the object to be processed and fine particles.At this time, carbon dioxide gas generated by endotherm is replaced with air to form an inert atmosphere,
The object can be frozen substantially instantaneously. Such a frozen product exists in a mixed state of the processing object and the dry ice. In the present invention, it is preferable that such a mixture of the object and the dry ice be contained in a container for the object to be processed and freeze-dried. When a mixture of the object and dry ice is used, when heated by a heating device, the objects to be processed are separated from each other with the sublimation of the dry ice. Drying efficiency increases.

In the present invention, the object to be processed, which has been cooled and frozen by a refrigerant such as dry ice or the like, is made of a bag made of a permeable material such as cloth, nonwoven fabric, paper, etc., through which the gas and water vaporized by the refrigerant can freely pass. And freeze-dried by a freeze-drying apparatus.

The freeze-drying apparatus includes an apparatus main body having a closed chamber, and accommodates a gas-permeable object container for accommodating an object to be frozen which is in contact with a refrigerant, and rotates and inverts the object to be processed. Provide a rotating cage in a closed room to move,
A heating device is provided in the device main body to heat the object to be processed,
A structure is provided in which a vacuum generator for reducing the pressure in the closed chamber through a cold trap provided with a cooling unit is provided.

The main body of the freeze-drying apparatus having the closed chamber may have any structure as long as it can heat and decompress while rotating the rotating cage, and its shape is not limited. The rotating cage houses the container to be processed and is configured to rotate in a closed chamber, but because it is heated by the heat radiated from the heating device,
Cages made of stainless steel, plastic, and other materials that easily pass radiant heat, such as meshes and punched boards
It is preferably formed in a shape. The rotating cage is preferably one that is rotated or inverted at a low speed of 1 to 10 rpm by a motor in order to uniformly radiate the radiant heat of the heating device to the processing object accommodated in the processing object container. The rotating cage can be, for example, a magnet-driven cage configured to rotate by transmitting the power of a motor by a magnetic coupling (magnetic coupling), or between the closed chamber and the rotating cage. A configuration is also possible in which a rotating roller is provided and the power of the motor is directly transmitted to the rotating roller to rotate.

The heating device is preferably installed inside and / or outside the closed chamber so as to heat the rotating cage from the outside. When the object to be processed is heated by the heating device, the dry ice mixed with the object to be processed also sublimes. Therefore, it is preferable that the heating device be configured so that the heating conditions can be changed in the state of sublimation of the dry ice. In this case, 30 to 100 ° C., preferably 60 ° C. before the completion of the sublimation of dry ice.
A temperature suitable for sublimation of dry ice and a temperature passed through sublimation of ice by performing heating so that the temperature is maintained at ~ 80 ° C and after completion of sublimation, 20 ~ 80 ° C, preferably 20 ~ 40 ° C. , And dry ice and moisture can be efficiently removed. Whether or not the sublimation of the dry ice has been completed can be determined by detecting a change in the temperature of the container to be processed, a change in the pressure in the closed chamber, a change in the concentration of carbon dioxide in the exhaust gas, and the like.

The above-described heating device is a heating lamp or a far-infrared ceramic heater having a high spectral emission characteristic in a carbon dioxide absorption region in order to efficiently remove dry ice mixed with the object in the object container. Sublimates the dry ice by heating at the same time. After detecting the change of carbon dioxide gas due to the disappearance of the dry ice or the temperature rise of the object to be treated by a CO ₂ gas sensor, thermocouple, thermistor, thermography, etc., the heater output is reduced. It is preferable that the control is performed by a control device having a sequence capable of performing drying while preventing thermal denaturation of the processing object. When a heating lamp is used, it is excellent in that rapid heating by radiant heat and overall heating by reflection are performed. When a heating lamp is used, it is preferable that the inner surface of the closed chamber is made of a material such as stainless steel capable of mirror reflection.

It is preferable that the vacuum generator be configured so that the conditions for evacuation can be changed before and after the completion of the sublimation of dry ice. For freeze-drying, set the pressure in the closed chamber to 0.1 to 1
000 Pa, preferably 0.1 to 100 Pa, more preferably 0.1 to 10 Pa,
Since a large amount of carbon dioxide is generated before the sublimation of dry ice, a large amount of gas is discharged by a vacuum pump with a large gas discharge capacity, and after the sublimation of dry ice, a high vacuum is maintained by a vacuum pump that maintains a high vacuum. Can be maintained. In this case, as the vacuum generator, a device that combines a high-displacement vacuum pump such as a mechanical booster pump for discharging a large amount of carbon dioxide gas sublimated from dry ice by heating, and a normal rotary vacuum pump is used. It is preferable that these are provided and controlled by a control device.

In the above-mentioned freeze-drying by the freeze-drying apparatus, an object container for accommodating an object to be cooled which is cooled by a refrigerant and frozen is accommodated in a rotating cage in the freeze-drying apparatus, and the object to be treated in the rotating cage is stored. The object is rotated while being moved by rotation, inversion or the like, and is depressurized by a vacuum device, thereby maintaining a vacuum state, and heating the object to be processed by the heating device to sublimate the moisture contained in the object by heating. And freeze-dried to obtain a freeze-dried product.

In the above-mentioned method, since the frozen material is stored in a gas-permeable processing object container, vacuum-dried while being stored in a rotating cage and rotated, a large amount of processing object can be stored, and dry ice can be stored. A large amount of carbon dioxide gas generated by sublimation of dry ice from the object frozen in a mixed state with water and moisture in the frozen matter can be efficiently removed, and the efficiency of freeze-drying can be improved. In addition, by rotating the object to be dried while rotating, the surface area can be prevented from decreasing due to the adhesion of the objects to be processed, and the drying time of the frozen material can be shortened. A high-quality freeze-dried product can be prepared by preventing quality deterioration caused by the lyophilization.

By changing the heating conditions of the heating device before and after the completion of the sublimation of the dry ice, the sublimation can be performed efficiently, and the freeze-drying can be performed at a temperature at which the object to be treated can be prevented from being altered. In addition, by changing the conditions of vacuuming according to the state of sublimation of dry ice, vacuuming can be performed under conditions suitable for discharging sublimated carbon dioxide gas and moisture, and freeze-drying can be performed efficiently.

When a refrigerant other than dry ice, for example, liquid nitrogen is used as the refrigerant, the object to be treated can be frozen by a method such as immersion in liquid nitrogen. In order to prevent a decrease in the surface area due to the adhesion of the objects to be processed and to improve the drying efficiency, it is preferable that the objects to be processed are accommodated in the object container in a state where the objects are not bonded to each other. Here, the state in which the workpieces are not bonded to each other means
This refers to a state in which the objects to be processed are separated from each other, or a state in which the separated state can be ensured by rotation of the rotating cage.

When liquid nitrogen is used, no gas evaporates from the refrigerant as in the case where dry ice is used, or even when it is generated, the amount is small. For this reason, most of the gas generated by heating the object to be processed is ice in the object to be processed or water vapor that is sublimated ice attached to the object to be processed, so that heating is performed at a temperature suitable for sublimation of the ice. When dry ice is used, control of heating conditions before and after the completion of sublimation of dry ice can be omitted. Further, as the vacuum generator, the high displacement vacuum pump can be omitted, and processing can be performed using only a common rotary vacuum pump.

The freeze-dried product obtained as described above is
Depending on the substance to be treated, the substance is stored or transported as it is or as a dry substance such as foods, pharmaceuticals, biological samples, feeds, industrial raw materials, etc., mixed with other dry substances. It can be reconstituted by adding water again, and can be used as, for example, foods, pharmaceuticals, biological samples, feeds, industrial raw materials, and the like.

[0025]

According to the present invention, since the air-permeable object container accommodating the object frozen by the refrigerant is accommodated in the rotating cage in the closed chamber and freeze-dried,
Even when dry ice is used as the refrigerant, a large amount of carbon dioxide gas generated by sublimation of dry ice from the frozen object to be processed and moisture from the frozen material can be efficiently removed, and the object to be processed can be rotated. By drying while drying, it is possible to prevent adhesion of the objects to be processed, shorten the drying time of the frozen material, and obtain a high-quality freeze-dried material because the frozen material can be uniformly heated.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a freeze-drying apparatus according to an embodiment,
FIG. 2 is a perspective view in which a part of the apparatus main body is cut away. The apparatus main body 1 is formed in a cylindrical shape, and a closed chamber 2 is formed therein. A rotating cage 3 is rotatably provided in a sealed chamber 2 via a rotating roller 5 so that the rotating cage 3 rotates with the object container 4 accommodated therein. A heating device 6 is provided on the inner wall of the apparatus main body 1 so that the frozen matter in the object container 4 can be heated through the rotating cage 3. The apparatus main body 1 is supported by a support base 7 and has a sealing door 8 at one end and an electric motor 9 for rotating the rotating cage 3 at the other end. It is preferable that the power of the electric motor 9 be transmitted to the rotating cage 3 through a magnet coupling, because vacuum leakage can be prevented. In this case, a drive magnet (not shown) is provided outside the closed chamber 2, and a driven magnet (not shown) is provided inside the closed chamber 2, and the drive magnet rotates by the power of the electric motor 9 and follows the rotation of the drive magnet. Then, the driving magnet and the driven magnet form a magnetic coupling so that the driven magnet rotates, and the rotation cage can be rotated by the rotation of the driven magnet. Further, the electric motor 9 may rotate the rotating cage 3 by directly transmitting power to the rotating roller 5 provided between the closed chamber 2 and the rotating cage 3.

An exhaust port 10 for exhausting carbon dioxide gas and moisture sublimated from dry ice and frozen matter is provided at an end of the apparatus body 1, a conduit 11 having a valve V1, and valves V2 and V3. Conduit 12 with
Cold traps 13a and 13b are connected via a and 12b. Cooling pipes 15a and 15b are provided in the cold traps 13a and 13b so that the refrigerant for collecting moisture cooled by the refrigerator 16 circulates to collect the water discharged from the closed chamber 2 by freezing. Has become. A mechanical booster type vacuum pump 17a and an oil rotary vacuum pump 17b are connected in series to the cold traps 13a and 13b via conduits 14a and 14b having valves V4 and V5, respectively. Preferably, it is configured to be able to maintain a vacuum of about 0.1 to 10 Pa.

The heating device 6 may be a conventional one.
A radiant heat type, a conduction heat type or a convection type may be used, but a radiant heat type device is preferable. In FIG. 2, a plurality of ceramic heaters are provided on the inner wall of the closed chamber 2 as the heating device 6, and are uniformly distributed to the frozen matter and the dry ice inside the processing object container 4 accommodated therein as the rotating cage 3 rotates. Irradiation is performed by infrared rays or the like. As the heating device 6,
A flat heater may be provided instead of the far-infrared ceramic heater.

Reference numeral 20 denotes a control device, which is a CO ₂ gas sensor 24 provided near the exhaust port 10 and a temperature detecting device 21a.
Alternatively, the power supply device 22 of the heating device 6 is controlled by a temperature signal of the radiation thermometer 21b or the like from a temperature detection window 23 provided in the device main body 1.

Next, a method for freeze-drying with the above-described apparatus will be described. First, the refrigerator 16 is turned on, and when the temperatures of the cold traps 13a and 13b reach −40 ° C. or lower, a frozen product to be processed that has been frozen with dry ice is put into the processing container 4 and the opening is opened. After closing 4a,
It is housed in the rotating cage 3. And after closing the closed door 8,
Operate the vacuum pumps 17a and 17b, and the degree of vacuum is about 50P
At time point a, the rotating cage is rotated at 1 to 10 rpm while operating the heating device 6 to uniformly radiate radiant heat. With the sublimation of the dry ice due to the heating, the objects to be processed are easily moved, and the rotation of the rotating cage prevents the objects to be processed from adhering to each other. Before the sublimation of dry ice, a large amount of carbon dioxide generated by sublimation is efficiently exhausted mainly by the mechanical booster 17a.
The sublimation state of the dry ice is monitored by the temperature detection device 21a provided near the exhaust port 10, and when the sublimation of the dry ice is almost completed and a sharp temperature rise of about 20 ° C. is detected, the control signal from the control device 20 is output. Is sent to the power supply device 22, and the heating by the heating device 6 is switched to the weak setting to prevent the quality from deteriorating. After the sublimation of the dry ice is completed, only the moisture is sublimated, so that the gas is exhausted with high efficiency mainly by the oil-rotating vacuum pump 17b to maintain a high degree of vacuum. The water sublimated from the frozen material is frozen and collected in the cold traps 13a and 13b, the drying of the frozen material progresses, and the dried processed object is stored in the processed object container 4 as a product.

In the above-mentioned apparatus, the rotating cage 3 and the heating device 6 for supplying sublimation latent heat are installed inside the closed chamber 2, and a highly permeable material for storing dry ice and frozen material to be processed is provided. By accommodating the processing object container 4 in the rotating cage 3 and gently rotating it, the rotation of the cage can prevent the processing object inside the processing object container 4 from overlapping, thereby improving the drying effect and radiating from the heating device 6. The heat is uniformly applied, so that quality deterioration due to partial heating can be prevented. By rotating the rotating cage 3 inside the closed chamber 2 in this way, it is possible to increase the drying efficiency and prevent the quality of the material from deteriorating. The object to be processed is taken out of the closed chamber 2 when dried, and stored in a dry state.

FIG. 3 is a front view of a freeze-drying apparatus according to another embodiment, in which a heating lamp such as a halogen lamp is used as an apparatus for heating an object to be processed. In FIG. 3, the heating lamp 25 is provided outside the closed chamber 2, and irradiates an object to be processed in the closed chamber 2 through a heating window 26 made of a transparent heat-resistant tempered glass provided in a part of the apparatus main body 1. And heated. The inner surface of the closed chamber 2 is made of stainless steel so that light emitted from the heating lamp 25 is specularly reflected. The control device 20 is a heating lamp 2
5 is controlled, and upon detecting a temperature rise at which the sublimation of dry ice is almost completed, a control signal is sent from the control device 20 to the heating lamp 25 to switch the heating to a weak setting. One or more heating lamps 25 can be provided. When a heating lamp is provided, the heating device 6 in the closed chamber 2 shown in FIG. 2 can be omitted.

When liquid nitrogen is used as the refrigerant instead of dry ice, the mechanical booster type vacuum pump 17a can be omitted because the amount of gas generated upon heating is small. Further, it is preferable that the object to be processed is accommodated in the object to be processed container 4 and freeze-dried in a state where the object is not bonded or in a state where rotation and reversal can be ensured by rotation of the rotating cage 3.

[Brief description of the drawings]

FIG. 1 is a front view of a freeze-drying apparatus according to an embodiment.

FIG. 2 is a perspective view in which a part of an apparatus main body is cut away.

FIG. 3 is a front view of a freeze-drying apparatus according to another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Closed chamber 3 Rotating cage 4 Object container 5 Rotary roller 6 Heating device 7 Support base 8 Sealing door 9 Motor 10 Exhaust port 11, 12a, 12b, 14a, 14b Conduit 13a, 13b Cold trap 15a, 15b Cooling Tube 16 Refrigerator 17a, 17b Vacuum pump 20 Controller 21a Temperature detector 21b Radiation thermometer 22 Power supply 23 Temperature detection window 24 CO ₂ gas sensor 25 Heating lamp 26 Heating window

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3L113 AA06 AB06 AC10 AC24 AC68 BA01 DA10 DA24 4B022 LB06 LF10 LF12 LR06 4C076 AA29 GG06

Claims (15)

[Claims] A permeable object container for accommodating an object to be processed which has been cooled and frozen by a refrigerant is accommodated in a rotating cage in a freeze-drying apparatus, and the object to be processed is heated by a heating device under vacuum conditions. A method for producing a freeze-dried product, wherein the freeze-dried product is obtained by heating and sublimating moisture in the object to be treated. 2. The method according to claim 1, wherein the objects to be processed are accommodated in a container to be processed in a state where they are not bonded to each other. 3. The method according to claim 1, wherein the heating device is a heating lamp. 4. The method according to claim 1, wherein the refrigerant is dry ice. 5. The method according to claim 4, wherein the object to be processed is contained in a container to be processed in a state of being mixed with dry ice. 6. The method according to claim 4, wherein the freeze-drying is performed by changing the heating conditions according to the state of sublimation of the dry ice. 7. The method according to claim 4, wherein the freeze-drying is carried out by changing the condition of evacuation according to the state of sublimation of the dry ice. 8. The method according to claim 1, wherein the refrigerant is liquid nitrogen.
The method according to any of the above. 9. An apparatus main body having a closed chamber, and a rotating cage provided in the closed chamber so as to rotate while accommodating and rotating a gas-permeable workpiece container which holds a frozen workpiece cooled by a refrigerant. A freeze-drying apparatus including a heating device provided in the main body so as to heat the object to be processed, a cold trap connected to the closed chamber and having a cooling unit, and a vacuum generator for reducing the pressure in the closed chamber through the cold trap. . 10. The apparatus according to claim 9, wherein power transmission for rotating the rotating cage is performed by a magnetic coupling. 11. The heating device according to claim 9, wherein the heating device is a heating lamp.
Or the apparatus according to 10. 12. The apparatus according to claim 9, wherein the heating device is configured such that when the refrigerant contains dry ice, the heating condition can be changed according to the state of sublimation of the dry ice. 13. The vacuum generating apparatus according to claim 9, wherein when the refrigerant contains dry ice, a vacuuming condition can be changed according to a state of sublimation of the dry ice.
3. The device according to any one of 2. 14. A freeze-dried product produced by the method according to claim 1. 15. A food or medicine containing the freeze-dried product according to claim 14.