JP3769498B2 - Vacuum microwave thawing machine and vacuum microwave thawing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum microwave thawing machine that heats and thaws an object to be thawed by irradiating microwaves in a reduced pressure state, and a vacuum microwave thawing method that is performed by the thawing machine.
[0002]
[Prior art]
A conventional vacuum microwave thawing machine is an apparatus for thawing an object to be thawed by irradiating microwaves in a pressure reduction process while repeatedly performing a pressure reduction process and a pressure reduction process. The machine includes a chamber for storing the material to be thawed, a vacuum pump for decompressing the chamber, a decompression means for decompressing the chamber decompressed by the vacuum pump, and irradiating the chamber with microwaves in the decompression step. A microwave generator.
[0003]
In this type of vacuum microwave thawing machine, when a certain suction force is applied by a vacuum pump, the change in reduced pressure per unit time at this time is detected by a vacuum sensor, and the reduced pressure change is reduced and it can be considered that the equilibrium state has been reached. The temperature of the object to be thawed was estimated from the pressure of the thawing, and when the estimated temperature reached the thawing end temperature, the thawing operation was finished.
[0004]
[Problems to be solved by the invention]
However, in the conventional vacuum microwave thawing machine, the temperature of the object to be thawed is not directly detected, so even if the object to be thawed is locally heated by uneven heating, it is estimated as the average temperature of the object to be thawed. Therefore, at the end of the thawing operation, for example, a part of the material to be thawed becomes 0 ° C. or higher, and there is a possibility that the thawing finish in which the drip is generated is poor.
[0005]
As described above, the conventional vacuum microwave thawing machine cannot cope with the temperature variation due to the part to be thawed.
[0006]
Therefore, the present invention can detect the surface temperature of multiple parts of the object to be thawed and perform heating operation so that local heating of the object to be thawed does not occur, realizing a good thawing finish without drip generation An object of the present invention is to provide a vacuum microwave thawing machine that can be used, and a vacuum microwave thawing method performed using the same.
[0007]
[Means for Solving the Problems]
The present invention has been proposed in view of the above, and according to the first aspect of the present invention, there is provided a chamber for storing an object to be thawed, a vacuum pump for reducing the pressure in the chamber, and a pressure regulating valve for returning the pressure in the chamber. A microwave generator for irradiating the inside of the chamber with microwaves, and a control device for controlling the vacuum pump, the pressure regulating valve, and the microwave generator. In a vacuum microwave defroster that heats and defrosts the object to be thawed by irradiating microwaves while repeating the pressure step,
In the chamber, a non-contact type temperature sensor that detects the surface temperature of a plurality of locations of the object to be thawed and outputs a temperature detection value of each detection location is provided,
The controller is configured to stop the output of the microwave generator when the average of the temperature detection values reaches a reference value, and stop the decompression to open the chamber to the atmosphere,
The vacuum microwave thawing machine is characterized in that a temperature signal from the non-contact type temperature sensor is input to the control device to manage the temperature of an object to be thawed at a plurality of locations.
[0009]
According to a second aspect of the present invention, when the control device is such that the average temperature detection value is lower than the reference value and the temperature difference between the detection points is equal to or higher than a predetermined temperature set in advance. Reduce the output of the microwave generator and / or shorten the irradiation time and continue the thawing cycle. When the average of the temperature detection values reaches the reference value, the output of the microwave generator is stopped and the decompression is stopped. The vacuum microwave defroster according to claim 1, wherein the chamber is open to the atmosphere.
[0010]
According to a third aspect of the present invention, when the control device is a temperature at which the average of the temperature detection values is lower than the reference value, and the temperature difference between the detection points exceeds a predetermined temperature set in advance, The vacuum microwave thawing machine according to claim 1, wherein the thawing operation is stopped by stopping wave output.
[0011]
What is described in claim 4 is a vacuum microwave thawing method in which the object to be thawed is heated and thawed by irradiating microwaves while repeatedly performing the decompression step and the decompression step.
Detects the surface temperature at multiple locations of the material to be thawed, stops the microwave output when the average of the temperature detection values reaches the reference value, and stops the decompression to open the chamber containing the material to be thawed to the atmosphere Then, the vacuum microwave thawing method is characterized by terminating the thawing operation.
[0012]
According to a fifth aspect of the present invention, when the average of the temperature detection values is lower than a reference value and the temperature difference between the detection points is equal to or higher than a predetermined temperature, the output of the microwave is reduced and / or 5. The vacuum microwave thawing method according to claim 4 , wherein the thawing cycle is continued by shortening the irradiation time, and the thawing operation is terminated when the average of the temperature detection values reaches a reference value.
[0013]
What is described in claim 6 is a vacuum microwave thawing method in which the object to be thawed is heated and thawed by irradiating microwaves while repeating the decompression step and the decompression step.
Detecting the surface temperature at multiple locations of the object to be thawed, and if the temperature difference between the detected locations of the temperature detection values exceeds a predetermined temperature, stop the microwave output and interrupt the thawing operation A vacuum microwave thawing method characterized.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing the appearance of the vacuum microwave defroster of the present embodiment. FIG. 2 is a schematic view showing the internal structure of the right side surface of the vacuum microwave defroster according to the present embodiment.
[0015]
As shown in FIG. 1, the vacuum microwave thawing machine 1 of the present embodiment is provided with a food container 3 for storing an object to be thawed such as frozen food at the upper part of the housing 2, and a drive described later at the lower part. A machine storage unit 4 that stores a motor, a vacuum pump, and the like is disposed, and a control unit 5 that stores a control device is provided at the top, and the weight of the object to be thawed is placed on the front panel of the control unit 5. And a display unit 6 for displaying the decompression time and the like, and an operation unit 7 for inputting power on / off and various setting values. In addition, a caster 8 for facilitating the movement of the thawer 1 is provided on the lower surface of the casing 2 of the vacuum microwave thawer 1.
[0016]
As shown in FIGS. 1 and 2, the main body of the food container 3 in the vacuum microwave thawing machine 1 of the present embodiment is constituted by a hollow box-shaped chamber 10 having an opening on the front surface, and the chamber 10 is an electromagnetic wave. It is formed as a metal pressure-tight airtight container having an inner wall structure capable of blocking A door 11 capable of closing the inside of the chamber 10 in a sealed state is attached to the front opening of the chamber 10 through a hinge portion at the right front end of the chamber 10 so as to be openable and closable. On the left side of the front surface is attached a handle 12 that is gripped during the opening / closing operation. Between the door 11 and the chamber 10, an electromagnetic wave sealing material made of a metal net string and a chamber for preventing electromagnetic waves from leaking to the outside. An airtight sealing material that maintains the airtightness of the inside 10 is mounted.
[0017]
At the bottom of the chamber 10, a rotating shaft 13 is rotatably supported in a state of being supported by a bearing 14, and an object to be thawed is placed on the upper end of the rotating shaft 13 in the chamber 10. Then, the rotating turntable 15 is detachably attached, and a table driving motor 16 is connected to the base end portion of the rotating shaft 13 via a speed reduction mechanism.
[0018]
A central portion of the back surface of the chamber 10 is placed on the turntable 15 by irradiating the chamber 10 with microwaves via a straight waveguide 20 and a reducer waveguide 21 communicating with the chamber 10. A microwave generator 22 for heating the object to be thawed is connected. In this embodiment, a magnetron is employed as the microwave generator 22, and a pressure partition made of a glass plate that easily transmits microwaves to the flange connection portion 23 between the straight waveguide 20 and the reducer waveguide 21. Is installed.
[0019]
A discharge detection sensor 30 is provided at the upper back of the chamber 10 to detect when a discharge occurs in the chamber 10 due to microwave irradiation. A UV sensor that is determined by detecting ultraviolet rays (UV) is employed. A vacuum pressure sensor 31 that detects the pressure in the chamber 10 is provided in front of the upper portion of the chamber 10.
[0020]
An upper part of the chamber 10 includes an air release valve 40 that releases the pressure in the chamber 10 to the atmosphere, and a pressure regulating valve 41 that adjusts the pressure in the chamber 10. Further, a decompression system 43 for decompressing the interior of the chamber 10 is connected to the back surface of the chamber 10, and a vacuum pump 46 driven by a pump drive motor 45 is connected to the decompression system 43 via a check valve 44. Yes. The air release valve 40 and the pressure regulating valve 41 are constituted by, for example, electromagnetic valves in order to enable opening / closing control by a control device housed in the control unit 5.
[0021]
In addition, a non-contact type temperature sensor 70 that detects surface temperatures of a plurality of places of the object to be thawed placed on the turntable 15 is provided on the ceiling surface portion in the chamber 10. For example, an infrared temperature sensor having an infrared element as the temperature detection element 71 is suitable. In the present embodiment, as the non-contact type temperature sensor 70, as shown in FIGS. 2 and 3, a non-contact type temperature sensor that includes a plurality of temperature detection elements 71 as a single unit is adopted. It is not limited to. For example, a plurality of non-contact type temperature sensors provided with a single temperature detecting element may be provided individually. In addition, in order to control the thawing operation by calculating the temperature detection value (temperature signal) of the location detected by each temperature detection element 71 by the control device 50 described later, for example, a, b, c, d in FIG. As shown in ..., it is desirable to output each temperature detection value.
[0022]
In FIGS. 2 and 3, for the sake of convenience, a single non-contact type temperature sensor 70 is illustrated as having four temperature detection elements 71, but the number thereof is the directivity of the temperature detection element 71. The position where the non-contact temperature sensor 70 is attached is not limited to the ceiling surface portion in the chamber 10 as in this embodiment, and the temperature of the object to be thawed is set. Any position that can be detected may be used. For example, the back surface portion or the side surface portion in the chamber 10 may be used.
[0023]
FIG. 4 is a block diagram showing a control system in the vacuum microwave thawing machine 1 of the present embodiment.
The control device 50 is housed in the control unit 5 described above, and is configured by, for example, a microcomputer that executes a control program recorded in the ROM 51. The control device 50 includes a power control system 52 for the table drive motor 16 that rotationally drives the turntable 15, a power control system 53 for the pump drive motor 45 that drives the vacuum pump 46, and the atmosphere release valve 40. Open / close control system 54, open / close control system 55 of the pressure regulating valve 41, power source control system 56 of the microwave generator 22, detection value input system 57 of the discharge detection sensor 30, and vacuum pressure sensor 31. A detection value input system 58, a detection value input system 72 of the non-contact type temperature sensor 70, an input system 59 such as a set value of the operation unit 7, and a display output system 60 of the display unit 6 are connected. The control recorded in the ROM based on the set value of the operation unit 7 and the detection values of the discharge detection sensor 30, the vacuum pressure sensor 31, and the non-contact temperature sensor 70, etc. For driving and controlling the respective devices such as the pump drive motor 45 and the microwave generator 22 in accordance with the program.
[0024]
Next, the vacuum microwave thawing method of the present embodiment performed using the vacuum microwave thawing machine 1 as described above will be described. FIG. 5 is an explanatory diagram showing a thawing cycle in the vacuum microwave thawing machine 1 of the present embodiment.
[0025]
As shown in FIG. 5, the vacuum microwave thawing machine 1 of the present embodiment repeatedly performs the decompression steps G, G ′, G ″... And the decompression steps F, F ′. However, this is an apparatus for heating and thawing the object to be thawed by irradiating microwaves M, M ′, etc. The vacuum pump 46 continues to operate during the decompression process as well as the decompression process.
[0026]
As a preparation stage for thawing, first, the front door 11 is opened and an object to be thawed such as frozen food is placed on the turntable 15, and the door 11 is closed again to be in a sealed state. Contains the thaw. Note that the atmosphere release valve 40 and the pressure regulating valve 41 are closed.
[0027]
Next, the pump drive motor 45 is driven to operate the vacuum pump 46, and pressure reduction in the chamber 10 is started via the pressure reduction system 43. Then, the pressure reduction degree gradually decreases from 101.3 kPa (760 Torr) of the atmospheric pressure through the point A, and the pressure reduction step G is performed to the pressure reduction equilibrium region B. In this pressure reduction step G, the material to be thawed is pre-dried. .
[0028]
Here, the decompression equilibrium region is a region in which the degree of decompression with respect to a certain time is extremely reduced. For example, the degree of decompression (ΔP) in 30 seconds (Δt) is ΔP / Δt <13.3 Pa (0.1 Torr). Although it is sometimes grasped that the decompression equilibrium region has been reached, the equilibrium pressure in the decompression equilibrium region rises and falls due to the saturated vapor pressure in the chamber 10. Whether or not the pressure reduction equilibrium range has been reached is determined by the control device 50 based on the pressure signal from the vacuum pressure sensor 31.
[0029]
After performing the decompression step G to the decompression equilibrium region B, the pressure regulating valve 41 is opened at a predetermined opening degree to be described later, and the process proceeds to the decompression step F. The degree of decompression in the decompression step F causes vacuum discharge. The microwave irradiation M by the magnetron 22 is started and set in advance at the point C after exceeding the lower limit P1 [set to 1.33 kPa (10 Torr) with some margin in this embodiment] When the pressure is restored to the return pressure upper limit D, the control device 50 closes the pressure regulating valve 41 based on the pressure signal from the vacuum pressure sensor 31, and then proceeds to the pressure reducing step G 'again. Then, the object to be thawed is heated by continuing the microwave irradiation M by the magnetron 22 up to the point A ′ before reaching the lower limit P1 at which the degree of decompression does not cause vacuum discharge. Stop irradiation.
[0030]
In the present embodiment, the lower limit P1 of the degree of decompression that does not cause vacuum discharge is set to 1.33 kPa (10 Torr) as described above. That is, at the point C after the degree of decompression in the decompression step F exceeds 1.33 kPa (10 Torr), the microwave irradiation M by the magnetron 22 is started and the decompression is restored to the preset decompression upper limit D. Then, the process proceeds to the decompression step G ′ again, and the microwave irradiation M by the magnetron is continued to the point A ′ just before the degree of decompression reaches 1.33 kPa (10 Torr) to heat the material to be thawed. As described above, since the microwave irradiation M is performed from the middle of the decompression process F to the decompression process G ′, one thawing cycle including the decompression process and the decompression process is performed as compared with the conventional case where irradiation is performed only in the decompression process. A sufficient irradiation time can be secured.
[0031]
The return pressure upper limit value D is a variable pressure value set by the output of the magnetron 22 that irradiates microwaves, the pressure reduction capability of the vacuum pump 46, and the volume of the chamber 10, and in this embodiment, the throttle of the pressure regulating valve 41 It is set to 6.66 kPa (50 Torr) by adjusting the throttle of the valve 41 ′. Therefore, when the pressure is restored to 6.66 kPa (50 Torr), the leak from the pressure regulating valve 41 and the suction capacity of the vacuum pump 46 balance, and the pressure rises while maintaining the pressure regulating valve 41 at 6.66 kPa (50 Torr). I do not.
[0032]
In the present embodiment, the pressure value of the decompression upper limit D is appropriately set in accordance with the output of the magnetron 22 that irradiates the microwave, the decompression capability of the vacuum pump 46, and the volume of the chamber 10, so that the vacuum discharge The microwave irradiation time without excess or deficiency can be taken before entering the generation area, and the pressure can be reduced efficiently.
[0033]
As a means for detecting that the return pressure upper limit value D has been reached, in the present embodiment, it is detected by a signal from the vacuum pressure sensor 31, whereby the control device 50 closes the pressure regulating valve 43 and shifts to the pressure reducing process. However, the present invention is not limited to this, and may be stopped by timer control.
[0034]
After the microwave irradiation is stopped, the object to be thawed is sublimated and cooled in the decompression process from the point A ′ to the decompression equilibrium region B ′. In this way, after the object to be thawed is heated by irradiating the microwave to the point A ′ in the decompression step G ′, the object to be thawed is sublimated and cooled in the decompression process from the point A ′ to the decompression equilibrium region B ′. When the object to be thawed is heated by irradiating with microwaves, the temperature of the surface part of the object to be thawed becomes higher than the temperature of the center part, and if heating is continued as it is, there will be inconveniences such as drip on the surface part. This is because the surface portion is cooled by sublimation to reduce the temperature difference between the inside and outside.
[0035]
That is, when sublimation starts, the latent heat of vaporization is deprived and the temperature of the surface portion decreases, and the heat of the surface portion moves (heat conduction) to raise the temperature of the central portion. As a result, the temperature of the material to be thawed is made uniform, and the temperature of the material to be thawed rises as a whole, and thawing is promoted. In addition, the thawing of the material to be thawed is promoted as a whole while the temperature of the material to be thawed is made uniform, so that thawing partially proceeds and drip is generated or microwaves concentrate on this drip. Can be prevented.
[0036]
In the present embodiment, the process proceeds to the decompression step F, and the microwave is generated at the point C after the decompression degree of the decompression step F exceeds the lower limit P1 of 1.33 kPa (10 Torr) that does not cause vacuum discharge. Irradiation M is started, and after returning to 6.66 kPa (50 Torr) which is a preset decompression upper limit D, the process proceeds to the decompression step G ′ again, and the degree of decompression is the lower limit P1 at which no vacuum discharge occurs. A thawing cycle in which microwave irradiation M is continuously heated to a point before A 'reaches 1.33 kPa (10 Torr), and after the microwave irradiation M is stopped, sublimation cooling is performed in the decompression process to the decompression equilibrium region B ′. Is repeated as one cycle.
[0037]
That is, in FIG. 5, after performing the decompression step G ′ to the decompression equilibrium region B ′, the process proceeds to the decompression step F ′, and the decompression degree of the decompression step F ′ is the lower limit value P1 at which no vacuum discharge occurs. At the point C ′ after exceeding 33 kPa (10 Torr), the microwave irradiation M ′ is started again, and after returning to 6.66 kPa (50 Torr) which is a preset decompression upper limit D ′, the pressure is reduced again. The process proceeds to step G ″, and the microwave irradiation M ′ is continuously heated until the pressure reaches 1.33 kPa (10 Torr) of A ″ which is the lower limit P1 at which the degree of decompression does not cause vacuum discharge. After the irradiation is stopped again, a defrosting cycle for sublimation cooling in the decompression process up to the decompression equilibrium region B ″ is performed as the second cycle. The decompression characteristics in each decompression process F, F ′. 41 'installation Because it depends on, constant in each thawing cycle, i.e., the curve of the condensate pressure curve is constant in each thawing cycle, which makes it possible to perform stable thawed.
[0038]
Such a thawing cycle is repeated to perform a thawing operation. As shown in FIG. 3, the non-contact temperature sensor 70 disposed on the ceiling surface in the chamber 10 always has a plurality of thawing objects 73. The surface temperature of the location is detected. The temperature detection value outputs a, b, c, d... At the detection points of the temperature detection elements 71 of the temperature sensor 70 are respectively input to the control device 50 via the detection value input system 72 and processed. The When the average of the temperature detection values reaches a reference value (for example, about −3 ° C.), the end of the thawing operation is determined.
[0039]
On the other hand, the average temperature detection value is lower than a reference value (for example, about −3 ° C.), and the temperature difference between detection points (for example, the temperature difference between a, b, c, and d in FIG. 3). Is equal to or higher than a predetermined temperature (for example, 1 ° C. or higher), the control device 50 reduces the microwave output of the magnetron 22 and / or shortens the microwave irradiation time and continues the thawing cycle. When the average of the temperature detection values reaches a reference value (for example, about −3 ° C.), the end of the thawing operation is determined as described above.
[0040]
In this way, when there is a temperature difference of a predetermined temperature or more depending on the part of the object to be thawed, the microwave output can be reduced or the irradiation time can be shortened, so that the heating can be gradually changed. In, heat conduction is performed from the high temperature portion to the low temperature portion, and the temperature is made uniform. Therefore, a local temperature rise in the object to be thawed can be avoided, whereby the whole is thawed evenly and the occurrence of drip can be prevented.
[0041]
Moreover, when the temperature difference between the detection points of the temperature detection value (for example, the temperature difference between a, b, c, and d in FIG. 3) exceeds a predetermined temperature range (for example, within 2 ° C.), the magnetron 22 micro The wave output may be stopped and the thawing operation may be interrupted. In this case, the decompression by the vacuum pump 46 is stopped, the inside of the chamber 10 accommodating the material to be thawed 73 is opened to the atmosphere, and the position of the material to be thawed 73 on the turntable 15 is changed. The thawing operation can be adjusted before 73 local heating progresses.
[0042]
When the controller 50 determines the end of the thawing cycle, the air release valve 40 is opened, the power source of the pump drive motor 45 is shut off, the vacuum pump 46 is stopped, and the inside of the storage chamber 9 returns to atmospheric pressure. The door 11 can be opened, and the material 73 to be thawed that has been thawed to about −3 ° C., which is the reference value, can be taken out of the chamber 10.
[0043]
As described above, in this embodiment, the temperature of a plurality of locations of the object to be thawed 73 is detected, and when the average of the temperature detection values reaches the reference value of about −3 ° C., the microwave output is stopped and the pressure is reduced. Is stopped, the inside of the chamber 10 containing the material to be thawed 73 is opened to the atmosphere, and the thawing operation is completed, so that the material to be thawed 73 is not evenly heated and a satisfactory thawing finish without drip is realized. Can do.
[0044]
Furthermore, when the average temperature detection value is lower than the reference value of about −3 ° C. and the temperature difference between the detection points is equal to or higher than a predetermined temperature (eg, 1 ° C. or higher), the output of the microwave And / or shortening the microwave irradiation time and continuing the thawing cycle, and then the thawing operation is terminated when the average temperature detection value reaches the reference value of about −3 ° C. Even when heating of the product (material to be thawed) is uneven, it is possible to finally achieve a thawed finish in a good state where no drip is generated.
[0045]
In the above embodiment, the infrared temperature sensor has been described as an example, but the non-contact temperature sensor of the present invention can be any configuration as long as the temperature can be detected without contacting the non-thawed material. The temperature sensor may be used. The temperature difference at which microwave irradiation is relaxed or stopped has been described as 1 ° C. and 2 ° C. in the embodiment, but this setting can be appropriately changed in design. However, in frozen foods, −3 ° C. is a suitable thawing temperature, and the set temperature is within 3 ° C., preferably within 1 ° C., in order to prevent the occurrence of drip.
[0046]
Moreover, although the to-be-thawed material was demonstrated as frozen food in the said embodiment, the to-be-thawed material thawed by this invention is not limited to food, Blood, serum, semen, a medicine, etc. may be sufficient.
[0047]
【The invention's effect】
As is clear from the above description, the vacuum microwave defroster of the present invention has the following excellent effects.
That is, when the temperatures of a plurality of locations of the object to be thawed are detected by the non-contact type temperature sensor, temperature management can be performed with higher accuracy than when the temperature of the material to be thawed is estimated from the equilibrium state. When the temperature is lower than the reference value at which thawing is completed and the temperature difference between the detection points is equal to or higher than a predetermined temperature, if microwave heating is weakened and thawing is continued, local heating of the object to be thawed is performed. A heating operation can be performed so as not to occur, and a satisfactory thawing finish without drip can be realized, and moreover, it can be performed efficiently.
[0048]
In addition, the temperature at a plurality of locations of the object to be thawed is detected, and when the temperature difference between the detected locations of the temperature detection value exceeds a predetermined temperature range, the microwave output is stopped and the thawing operation is interrupted. Then, the arrangement | positioning of the to-be-thawed object on a turntable can be changed, etc., and thawing operation can be adjusted before the local heating of the to-be-thawed object progresses.
[Brief description of the drawings]
FIG. 1 is a front view showing an appearance of a vacuum microwave defroster according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing the internal structure of the right side surface of the vacuum microwave defroster of the present embodiment.
FIG. 3 is a schematic view showing a non-contact temperature sensor in the vacuum microwave defroster of the present embodiment.
FIG. 4 is a block diagram showing a control system in the vacuum microwave defroster of the present embodiment.
FIG. 5 is an explanatory diagram showing a thawing cycle in the vacuum microwave thawing machine of the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vacuum microwave thawing machine 2 Housing | casing 3 Food storage part 4 Machine storage part 5 Control part 6 Display part 7 Operation part 8 Caster 10 Chamber 11 Door 12 Handle 13 Rotating shaft 14 Bearing 15 Turntable 16 Table drive motor 20 Direct guide Wave tube 21 Reducer waveguide 22 Microwave generator (magnetron)
23, 24 Flange joint 25 Pressure bulkhead 26 Depressurized area 27 Non-depressurized area 28 Elastic body 29 Bolt / nut 30 Discharge detection sensor 31 Vacuum pressure sensor 40 Atmospheric release valve 41 Pressure regulating valve 43 Depressurization system 44 Check valve 45 Pump drive motor 46 Vacuum Pump 50 Controller 51 ROM
52 Table Drive Motor Power Supply Control System 53 Pump Drive Motor Power Supply Control System 54 Atmospheric Open Valve Open / Close Control System 55 Pressure Regulator Open / Close Control System 56 Microwave Generator Power Supply Control System 57 Detection Value Input System 58 of the Discharge Detection Sensor Detection value input system 59 of vacuum pressure sensor 59 Input system 60 for setting value of operation unit Display output system 70 of display unit Non-contact temperature sensor 71 Temperature detection element 72 Detection value input system 73 of non-contact type temperature sensor

Claims (6)

A chamber for containing an object to be thawed, a vacuum pump for decompressing the inside of the chamber, a pressure regulating valve for restoring the pressure inside the chamber, a microwave generator for irradiating microwaves into the chamber, the vacuum pump, and a pressure regulating valve And a control device that controls the microwave generator, and under the control of the control device, the object to be thawed is heated and thawed by irradiating microwaves while repeating the decompression step and the decompression step. In vacuum microwave thawing machine,
In the chamber, a non-contact type temperature sensor that detects the surface temperature of a plurality of locations of the object to be thawed and outputs a temperature detection value of each detection location is provided,
The controller is configured to stop the output of the microwave generator when the average of the temperature detection values reaches a reference value, and stop the decompression to open the chamber to the atmosphere,
A vacuum microwave thawing machine , wherein a temperature signal from the non-contact type temperature sensor is input to the control device to manage the temperature of an object to be thawed at a plurality of locations. The control device reduces the output of the microwave generator when the average temperature detection value is lower than the reference value and the temperature difference between detection points is equal to or higher than a predetermined temperature set in advance. And / or shortening the irradiation time and continuing the thawing cycle, when the average of the temperature detection values reaches the reference value, the output of the microwave generator is stopped and the decompression is stopped to open the chamber to the atmosphere vacuum microwave thawing machine according to claim 1, characterized in that. When the temperature detection value average is lower than the reference value and the temperature difference between the detection points exceeds a predetermined temperature, the control device stops the microwave output and performs the thawing operation. The vacuum microwave thawing machine according to claim 1, wherein the vacuum microwave thawing machine is configured to interrupt the process . In the vacuum microwave thawing method in which the object to be thawed is heated and thawed by irradiating the microwave while repeatedly performing the decompression step and the decompression step,
  Detects the surface temperature at multiple locations of the material to be thawed, stops the microwave output when the average of the temperature detection values reaches the reference value, and stops the decompression to open the chamber containing the material to be thawed to the atmosphere And thawing operation is completed. When the average of the temperature detection values is lower than the reference value and the temperature difference between the detection points is equal to or higher than a predetermined temperature, the microwave output is reduced and / or the irradiation time is shortened to perform a thawing cycle. 5. The vacuum microwave thawing method according to claim 4, wherein the thawing operation is continued when the average of the temperature detection values reaches a reference value . In the vacuum microwave thawing method in which the object to be thawed is heated and thawed by irradiating the microwave while repeatedly performing the decompression step and the decompression step,
Detecting the surface temperature at multiple locations of the object to be thawed, and if the temperature difference between the detected locations of the temperature detection values exceeds a predetermined temperature, stop the microwave output and interrupt the thawing operation A vacuum microwave thawing method characterized .

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