JP2000136754A - Freeze-drying machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a complete drying condition under a ultra low temperature and save energy or improve environmental quality by applying a stirling freezer to a freeze-drying machine. SOLUTION: This freeze-drying machine has a heat exchange coil 53 arranged on the outer periphery and a freeze-drying tank 3 provided inside for storing dried material O, whereby cold refrigerant cooled by a cold head 45 of a stirling freezer 2 is circulated between the cold head 45 and the heat exchange coil 53 via a cold refrigerant pipe passage 54 for freeze-drying the freeze-drying tank 3 to dry the dried material O.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for quickly realizing a dry state by freezing water in a cooling bath, performing a characteristic test on the performance of electronic parts, industrial materials, and the like in a dry state. The present invention relates to a lyophilizer used to carry out experiments such as vital functions of cells in a dry state in the above, and particularly to a lyophilizer using a Stirling refrigerator.

[0002]

2. Description of the Related Art There has been known a freeze-dryer which freezes the water in a cooling bath to perform a drying environment test for electronic components, industrial materials, and the like. As a conventional freeze dryer, as a refrigerating device, a system using Freon (single, binary, or mixed refrigerant) as a refrigerant is known. In response to recent CFC regulations against the background of global environmental issues, HCF
C and refrigeration systems using HFC are known.

[0003] However, according to the above-mentioned conventional configuration,
There are the following problems. First, in the case of using the conventional refrigerating device and heating device, the temperature range is approximately -6.
It can only be set to about 0 to -80 ° C. In particular, a conventional cooling device using chlorofluorocarbon as a refrigerant has a narrow operating temperature range due to the characteristics of the system, and is particularly required in accordance with recent technological development in various industrial fields. It is not enough to meet the demand for complete drying in the ultra-low temperature range.

Second, the conventional freeze dryer requires a two-stage or two-stage refrigeration system in order to realize an ultra-low temperature range, and has a complicated structure and high cost.

[0005] Third, with the full-fledged international efforts to address global environmental issues, further restrictions on the use of CFCs, including specific CFCs and alternative CFCs, have been required in the future. The need for development has become important.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and specifically to solve the following problems. (1) It is possible to realize a completely dry state by setting the freezing temperature range to an ultra-low temperature range (about minus one hundred and several tens of degrees Celsius) as compared with the related art. (2) A simple, compact and low-cost structure is required without requiring a complicated structure such as a binary or two-stage refrigeration system. (3) To provide a freeze dryer which is adaptable to global environmental problems by enabling the use of a refrigerant other than conventional CFCs, has a high coefficient of performance, and has good energy efficiency.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a Stirling refrigerator having a cold head for charging a working gas and cooling a cold refrigerant and a heat exchanger for heat radiation, A replacement coil is provided,
A freeze-drying tank that can store the object to be dried inside,
A cold refrigerant cooled by the cold head is provided with a cold refrigerant pipe that circulates between the cold head and the heat exchange coil, and the Stirling refrigerator is operated to convert the cold refrigerant into a heat exchange coil. A freeze-drying machine characterized by flowing and freeze-drying a freeze-drying tank to dry an object to be dried.

Further, the present invention provides a Stirling refrigerator having a cold head for enclosing a working gas and cooling a cold refrigerant and a heat exchanger for heat radiation, a heat exchange coil disposed inside, and a heat exchanger. A freeze-drying tank capable of storing a dried body; and a cold / hot refrigerant line for circulating the cold refrigerant cooled by the cold head between the cold head and the heat exchange coil. A freeze-drying machine characterized by operating a machine to flow cold and hot refrigerant through a heat exchange coil, freeze-drying a freeze-drying tank, and drying an object to be dried.

According to the present invention, there is provided a Stirling refrigerator having a cold head for enclosing a working gas and cooling a cryogen, and a Stirling refrigerator having a heat exchanger for radiating heat, and a cryogen in which a cryogen is introduced and a body to be dried is stored. A drying tank and a cold refrigerant pipe for circulating the cold refrigerant cooled by the cold head between the cold head and the inside of the freeze-drying tank are provided, and the Stirling refrigerator is operated to freeze the cold refrigerant. A freeze dryer characterized in that it is introduced into a drying tank and freeze-dried to dry the object to be dried.

According to the present invention, there is provided a Stirling refrigerator having a cooling head for enclosing a working gas and cooling a cryogenic refrigerant and a heat exchanger for heat radiation, and the cold head is provided therein so as to penetrate from the bottom. A freeze-drying tank capable of storing the object to be dried; and a freeze-dryer characterized in that the object to be dried is dried by operating the Stirling refrigerator to freeze-dry the object.

The working gas of the above Stirling refrigerator is nitrogen, helium or hydrogen, and the cooling / heating refrigerant is ethyl alcohol, HFE (hydrofluoroether), PFC
(Perfluorocarbon), PFG (perfluoroglycol), nitrogen or helium.

Further, a temperature adjusting device for controlling the temperature by controlling the operation of the Stirling refrigerator may be provided.

The motor of the Stirling refrigerator may be controlled to rotate in the reverse direction so that the temperature of the freeze-drying tank can be raised.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on embodiments with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of the freeze dryer of the present invention. In FIG. 1, a freeze dryer 1 includes a Stirling refrigerator 2 and a freeze drying tank 3 in which cooling or heating is performed by the Stirling refrigerator 2.

The housing 4 of the Stirling refrigerator 2
It is formed by casting. The interior of the housing 4 is divided into a motor chamber 6 and a crank chamber 7 by a partition wall 5, and a motor 8 capable of normal and reverse rotation is provided in the motor chamber 6, and a rotating operation of the motor 8 is reciprocated in the crank chamber 7. A rotary reciprocating conversion mechanism 9 for converting into motion is provided. The motor chamber 6 and the crank chamber 7 are closed by lids 10 and 11, respectively, and the inside of the housing 4 is held in a semi-sealed state.

In the housing 4, the partition wall 5 is penetrated,
A crankshaft 15 pivotally supported by bearings 12, 13, and 14 is rotatably disposed. The motor 8 includes a stator 16 and a rotor 17 rotatably arranged inside the stator 16, and a crankshaft 15 is fixed to the center of the rotor 17.

The rotary reciprocating conversion mechanism 9 includes crank portions 18 and 19 of a crankshaft 15 extending into the crank chamber 7.
And connecting rods 20 and 21 connected to the crank portions 18 and 19, and cross guide heads 22 and 23 attached to the ends of the connecting rods, and function as drive transmission means of the Stirling refrigerator 2. .

The cross guide heads 22 and 23 are arranged so as to reciprocate in cross guide liners 24 and 25 provided on the inner wall of the cylinder of the housing 4. The crank portions 18 and 19 are formed with a phase difference so that the crank 19 moves ahead of the crank 18 when the motor 8 rotates in the forward direction and the crank 18 moves before the crank 19 when the motor 8 rotates in the reverse direction. Have been. As this phase difference, a phase difference of about 90 degrees is generally adopted.

A compression cylinder 26, a compression cylinder 26, and an expansion cylinder 27 are disposed above the crank chamber 7 of the housing 4 of the Stirling refrigerator 2. Compression cylinder 26, expansion cylinder 27, and housing 4
Inside, for example, helium, hydrogen, nitrogen and the like are sealed as working gas. The compression cylinder 26 has a compression cylinder block 28 fixed to the housing 4 by bolts or the like. A compression piston 29 provided with a piston ring slides back and forth in the space of the compression cylinder block 28, and The upper part is a high-temperature chamber (compression space) 30 in which the working gas is compressed to a high temperature.

The compression piston rod 31 has one end fixed to the compression piston 29, the other end extending through the oil seal 32 into the crank chamber 7, and connected to the cross guide head 22. Since the sliding direction of the reciprocating compression piston 29 is reversed at the top dead center and the bottom dead center, the speed becomes zero,
The velocity is slow near the top dead center and the bottom dead center, and the amount of change in volume per unit time is small, and at the respective middle points when moving from the bottom dead center to the top dead center and from the top dead center to the bottom dead center. The maximum speed is reached, and the amount of change in volume due to the movement of the compression piston 29 per unit time is also maximized.

On the other hand, the expansion cylinder 27 has an expansion cylinder block 33 fixed to the upper part of the housing 4 by bolts or the like. An expansion piston 34 provided with a piston ring reciprocates in the space of the expansion cylinder block 33. The upper part of this space is moved to a low temperature chamber (expansion space) 35.
The working gas therein expands to a low temperature. One end of an expansion piston rod 36 is fixed to the expansion piston 34, and the other end of the expansion piston rod 36 is connected to the oil seal 3.
7, extends into the crank chamber 7 and is connected to the cross guide head 23. The expansion piston 34 moves ahead of the compression piston 29 by a phase of about 90 degrees.

The expansion cylinder block 33 has a manifold 38, a heat-radiating heat exchanger (high-temperature side heat exchanger) 39, a regenerator 40, and a cooling heat exchanger (low-temperature side heat exchanger) communicating with each other from the bottom of the drawing. Numerals 41 are sequentially arranged in a ring shape so as to communicate with each other. Near the upper end of the compression cylinder block 28, a communication hole 44 that connects the high temperature chamber 30 and the manifold 38 is formed.

Although not shown, the heat-radiating heat exchanger 39 is an annular-type heat exchanger, for example, a shell-and-tube heat exchanger (a number of tubes for flowing a working gas into an annular heat-exchange chamber in an axial direction). A heat exchanger that penetrates and cools working gas by flowing cooling water into the heat exchange chamber.)
Alternatively, there is a heat exchanger or the like in which an annular jacket is provided around the annular working gas flow path, and cooling water flows in the jacket to cool the working gas.

The radiating heat exchanger 39 is connected to the cooling water circulation line 4.
2 and the radiator 43 via the cooling water pump P1 to circulate the cooling water. The cooling water heated and exchanged in the heat radiating heat exchanger 39 is cooled by the cooling fan of the radiator 43.

The heat-radiating heat exchanger 39 may be of an air-cooling type in which air-cooling fins are formed on the outer wall surface of the working gas flow path of the expansion cylinder block 33 instead of the water-cooling type as described above.

At the top (cold head 45) of the expansion cylinder block 33, a cooling heat exchanger 41 is provided as described above.
Are formed. The cooling heat exchanger 41 is provided with a working gas flow passage 4 formed inside the expansion cylinder block 33.
6 and cooling fins 47 formed on the outside. A jacket 48 is provided so as to entirely surround the cold head 45, and the jacket 48 has an inlet and an outlet for cold and hot refrigerant.

As shown in FIG. 1 (b), the freeze-drying tank 3 has a tank wall 50 formed of a metal material or the like surrounded by a heat insulating wall 49 from the outside. A shelf 52 on which the object to be dried O is placed is provided. A heat exchange coil 53 is wound around the tank wall 50 of the freeze-drying tank 3 and communicates with the cold / hot refrigerant pipe 54.

The cold refrigerant line 54 connects between the jacket 48 and the heat exchange coil 53 via the pump P2, and circulates the cold refrigerant between the cold refrigerant line 54 and the jacket 48. Ethyl alcohol, HF
E, PFC, PFG, nitrogen, helium and the like are used.

FIG. 5 shows a temperature controller 55 of the freeze dryer of the present invention. The temperature adjusting device 55 is disposed in the freeze-drying tank 3 and a temperature setting panel for setting a freezing temperature according to the purpose of drying and the like, a temperature control device for enabling temperature setting by the temperature setting panel. Has a temperature sensor. In the comparison circuit in the temperature control circuit constituting the temperature adjusting device 55, the temperature signal in the freeze-drying tank 3 detected by the temperature sensor is compared with the set temperature, and the temperature is set to an allowable temperature range centered on the set temperature. It is determined whether or not there is, and according to the result, the motor 8 is subjected to PID control or the motor 8 is rotated in the reverse direction to operate while maintaining the set temperature.

In the freeze dryer 1 of the present invention, the Stirling refrigerator 2 has two pistons of the compression cylinder 26 and the expansion cylinder 27, so that the volume fluctuation of the space filled with the working gas in the Stirling refrigerator 2 is increased. By doing so, it is possible to provide a Stirling refrigerator 2 having a large refrigeration capacity.

In the present invention, the two-piston type Stirling refrigerator 2 is used in the above embodiment, but it is needless to say that another type of Stirling refrigerator 2 such as a displacer type may be used.

Next, the freeze dryer 1 of the above embodiment of the present invention will be described.
The operation of will be described. The crankshaft 15 is rotated in the forward direction by the motor 8, and the crank 1 in the crank chamber 7 is rotated.
8 and 19 rotate out of phase with each other. Connecting rod 2 rotatably connected to these crank portions 18 and 19
The cross guide heads 22 and 23 attached to the leading ends of the connecting rods reciprocate in the cross guide liners 24 and 25 via 0 and 21. Cross guide head 2
The compression piston 29 and the expansion piston 34 connected to the tubes 2 and 23 via the compression piston rod 31 and the expansion piston rod 36 reciprocate with a phase difference from each other.

While the expansion piston 34 moves slowly near the top dead center ahead of about 90 degrees, the compression piston 29 moves rapidly toward the top dead center near the middle to perform the operation of compressing the working gas. The compressed working gas flows into the heat-radiating heat exchanger 39 through the communication hole 44 and the manifold 38.
The working gas that has radiated heat to the cooling water in the radiating heat exchanger 39
It is cooled by the regenerator 40 and flows into the low temperature chamber (expansion space) 35 through the passage 46.

When the compression piston 29 is slowly moving near the top dead center, the expansion piston 34 moves rapidly toward the bottom dead center, and the working gas flowing into the low temperature chamber (expansion space) 35 expands rapidly. Cold heat is generated. Thus, the cold head 45 surrounding the low temperature chamber (expansion space) 35 is cooled to a low temperature.

Then, the cold refrigerant in the jacket 48 is cooled in the cold head 45. Expansion piston 34
When the piston moves from the bottom dead center to the top dead center, the compression piston 2
Numeral 9 is from the intermediate position to the bottom dead center, and the working gas flows into the regenerator 40 from the low-temperature chamber (expansion space) 35 through the flow path 46 and stores the cold of the working gas in the regenerator 40.
The cold stored in the regenerator 40 is transferred to the high-temperature chamber 3 as described above.
The working gas sent from 0 through the heat-radiating heat exchanger 39 is reused for cooling again.

The cooling water exchanged in the heat-radiating heat exchanger 39 flows from the cooling-water circulation pipe 42 to the radiator 43, where it is cooled by a cooling fan and circulated to the heat-radiating heat exchanger 39 again.

The cold refrigerant cooled by the cold head 45 is sent from the jacket 48 to the cooling coil 53 through the cold refrigerant pipe 54. As a result, the freeze-drying tank 3 is cooled, the water in the tank is frozen, and the inside of the tank is dried. The object to be dried O is dried in the freeze-drying tank 3.

In order to remove frost when cleaning the freeze-drying tank, the motor 8 is rotated in the reverse direction. Then, contrary to the cooling operation described above, the crank 1
8 rotates ahead of the crank portion 19 with a phase shift of about 90 degrees. Then, contrary to the case of the cooling operation, the expansion cylinder 27 acts as a compression cylinder, the compression cylinder 26 acts as an expansion cylinder, and the cooling heat exchanger 41 is operated.
Functions as a heat exchanger for heat dissipation, and the temperature of the cold head 45 becomes high. Then, the cold refrigerant is heated and circulates through the jacket 48 and the freeze-drying tank 3. Thereby, the temperature of the inside of the freeze-drying tank is raised, and the frost frozen on the inner wall and the like and the frost on the cold head can be removed. Therefore, defrosting can be effectively performed even when an electric heater or the like is not particularly mounted.

In the operation state of the Stirling refrigerator 2, the temperature in the freeze-drying tank 3 is detected by a temperature sensor, and the detected temperature and the temperature set by the temperature setting panel are used as a temperature control circuit constituting a temperature control device. In the comparison circuit in the above, it is determined whether or not the temperature is within an allowable temperature range centered on the set temperature, and PID control of the motor 8 of the Stirling refrigerator 2 is performed according to the result. In some cases, such as when there is a large temperature difference in the detected temperature), the rotation direction of the motor 8 is switched to rapidly raise or lower the temperature,
Operate while maintaining the set temperature.

FIG. 2 shows a second embodiment of the present invention. FIG. 2A shows the entire structure, and FIG. 2B shows the main structure of the freeze-drying tank. In the freeze dryer 56, the structure of the Stirling refrigerator 2 in the first embodiment is completely the same, and the description thereof is omitted, but the structure of the freeze dryer 57 is different. The freeze-drying tank 57 is provided with a heat insulating wall 5 from the outside similarly to the first embodiment.
A tank wall 59 formed of a metal material or the like surrounded by 8 is provided, and an upper opening is provided with a lid 60 that can be opened and closed. Tank wall 59
A heat exchange coil 61 is wound around the inside of the tube, and communicates with the cold / hot refrigerant line 54. Further, the heat exchange coil 61
A support shelf 62 in the form of a lattice or a wire mesh for supporting the object O to be dried is provided inside the inside.

In the freeze dryer 56 of the second embodiment, the cold refrigerant cooled by the cold head 45
8 is sent to the heat exchange coil 61 through the cold refrigerant 54 by the pump P2. As a result, the freeze-drying tank 3 is cooled, the water in the tank is frozen, and the inside of the tank is dried.
The object to be dried O is dried in the freeze-drying tank 3.

FIG. 3 shows a third embodiment of the present invention. Also with respect to the freeze dryer 63 of this embodiment, the Stirling refrigerator 2 is the same as the Stirling refrigerator 2 of the first embodiment.
Although the description is omitted here, the freeze-drying tank 64 is used.
Structure is different. The freeze-drying tank 64 has a tank wall 65 formed of a metal material or the like surrounded by a heat insulating wall as in the first embodiment, and the object O to be dried is stored inside the tank wall 65. An accommodation room 66 is formed. Tank wall 65 and accommodation room 66
, A cold / hot refrigerant tank 67 communicating with the cold / hot refrigerant pipe 54.
Are formed, and the refrigerant is charged with the cold refrigerant.

In the freeze dryer 63 of the third embodiment, the cold refrigerant cooled by the cold head 45
8 to the cold / hot coolant tank 67 through the cold / hot coolant pipe 54. Thereby, the accommodation room 66 is cooled, and the accommodation room 66 is cooled.
Freezes the water inside and makes the inside of the tank dry.

FIG. 4 shows a fourth embodiment of the present invention. Also in the freeze dryer 67 in this embodiment, the Stirling refrigerator 2 is the same as the Stirling refrigerator 2 in the first embodiment.
Although the description is omitted here, the structure of the freeze-drying tank is different. The freeze-drying tank 68 has a tank wall 70 formed of a metal material or the like surrounded by a heat insulating wall 69 as in the first embodiment. Then, the cold head 45 of the Stirling refrigerator 2 is disposed in the freeze-drying tank 67, directly penetrating the bottom of the freeze-drying tank 67. In the freeze-drying tank 67, a lattice or wire net-like support shelf 7 on which the object to be dried O is placed is placed.
A storage chamber similar to that of the first or third embodiment is provided.

The freeze dryer 67 of the fourth embodiment can adjust the temperature in the freeze dryer 68 as in the first embodiment by disposing a temperature sensor in the freeze dryer 68. Since the cold head 45 is disposed directly in the freeze-drying tank 68, the freeze-dryer 67
The cooling effect in 8 is excellent.

[0046]

According to the above-described configuration, the present invention has the following effects. (1) By employing a Stirling refrigerator, a completely dry state can be realized in a freezing temperature range of an ultra-low temperature range (about one hundred and several tens of degrees Celsius) as compared with the conventional one, and no special heating device is required. Alternatively, the temperature can be raised and defrosted by reversing the motor, and the degree of dryness can be rapidly changed to provide an environmental test or cleaning. (2) A simple, compact and low-cost freeze dryer can be realized without requiring a complicated structure such as a two-stage or two-stage refrigeration system. (3) By making it possible to use a refrigerant other than conventional CFCs, it is possible to realize a freeze dryer that is adapted to global environmental problems, has a high coefficient of performance, and has good energy efficiency.

[Brief description of the drawings]

FIG. 1 is a diagram showing a freeze dryer according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a freeze dryer according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a freeze dryer according to a third embodiment of the present invention.

FIG. 4 is a diagram showing a freeze dryer according to a fourth embodiment of the present invention.

FIG. 5 is a diagram for explaining a temperature adjusting device of the freeze dryer of the present invention.

[Explanation of symbols]

 1, 56, 63, 67 Freeze-dryer 2 Stirling refrigerator 3, 57, 64, 68 Freeze-drying tank 8 Motor 26 Compression cylinder 27 Expansion cylinder 29 Compression piston 30 High temperature chamber (compression space) 34 Expansion piston 35 Low temperature chamber (expansion) (Space) 39 heat exchanger for heat dissipation 40 regenerator 41 heat exchanger for cooling 45 cold head 54 cold / hot refrigerant line

Continued on front page F term (reference) 3L113 AB10 AC16 AC21 AC45 AC46 AC52 AC57 AC63 AC65 AC67 AC75 AC79 BA34 CA08 CB13 CB28 CB34 DA02 DA06 DA13 DA14 DA20 DA26

Claims (7)

[Claims] 1. A Stirling refrigerating machine having a cold head for enclosing a working gas and cooling a cryogenic refrigerant and a heat exchanger for heat radiation, and a heat exchange coil disposed on an outer periphery, and a body to be dried is provided inside. A freeze-drying tank that can be stored, a cold-heat refrigerant pipe that circulates the cold-cooled refrigerant cooled by the cold head between the cold head and the heat-exchange coil, and includes the Stirling refrigerator. A freeze dryer, wherein the freeze dryer is operated to flow the cold refrigerant through the heat exchange coil, freeze-dry the inside of the freeze-drying tank, and dry the object to be dried. 2. A Stirling refrigerating machine having a cold head for enclosing a working gas and cooling a cold refrigerant and a heat exchanger for radiating heat, and a coil for heat exchange disposed therein and containing a body to be dried. A freeze-drying tank capable of performing the above-mentioned operation, and a cold-heat refrigerant pipe that circulates the cold-heat refrigerant cooled by the cold head between the cold head and the heat-exchange coil. The freeze-drying machine is further characterized by flowing the cold refrigerant through the heat exchange coil, freeze-drying the freeze-drying tank, and drying the object to be dried. 3. A Stirling refrigerator having a cold head and a heat radiating heat exchanger for enclosing a working gas and cooling a cryogen, a lyophilization tank in which a cryogen is introduced, and a body to be dried is stored. A cold refrigerant pipe that circulates the cold refrigerant cooled by the cold head between the cold head and the inside of the freeze-drying tank; and operates the Stirling refrigerator to freeze-dry the cold refrigerant. A freeze dryer characterized in that it is introduced into a tank and freeze-dried to dry the object to be dried. 4. A Stirling refrigerating machine having a cooling head for enclosing a working gas and cooling a cryogenic refrigerant and a heat exchanger for radiating heat, wherein the cold head is disposed inside so as to penetrate from the bottom, A freeze-drying machine, comprising: a freeze-drying tank capable of storing a body to be dried; and operating the Stirling refrigerator to freeze-dry the body to be dried. 5. The working gas of the Stirling refrigerator is nitrogen, helium or hydrogen, and the cryogenic refrigerant is selected from a group including ethyl alcohol, HFE, PFC, PFG, nitrogen and helium. The Stirling refrigeration apparatus according to claim 1. 6. The freeze dryer according to claim 1, further comprising a temperature adjusting device for controlling the temperature of the Stirling refrigerator by controlling the operation thereof. 7. The freeze-drying machine according to claim 1, wherein the motor of the Stirling refrigerator is controlled to rotate in the reverse direction so that the temperature of the freeze-drying tank can be increased.