JPH07246077A - Vacuum thawer - Google Patents

Abstract

PURPOSE:To provide the subject apparatus, equipped with a vent hole and a lid for hermetically sealing the vent hole in a hermetically sealed container capable of irradiating a frozen substance with microwaves in a vacuum state and capable of readily removing water condensed into dew in the container and preventing the thawing time from being prolonged. CONSTITUTION:This apparatus is obtained by installing a vent hole 10 in a hermetically sealed container 1 having a vacuum device 8 and a microwave generator 5 and further an elastic material on the side of the vent hole of a vent lid 11 for hermetically sealing the vent hole. The dew condensation on an inner wall of the container with steam produced by thawing or thermal cooking a frozen substance 2 such as fishes, shellfishes or meat is vaporized by the inflow of air from the vent hole and removed by the ventilation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum thawing device for heating a thawed body by irradiating the inside of a sealed container with a microwave and irradiating the inside with a microwave.

[0002]

2. Description of the Related Art Conventionally, as such a high-frequency heating device, a thawing device for thawing frozen foods has been disclosed in Japanese Unexamined Patent Publication No. Sho 63-63.
It is described in Japanese Patent Publication No. 79581.

In the thawing apparatus described in that publication, a vacuum pump and a magnetron for irradiating a high frequency are arranged in a container that can be sealed. The irradiation time for irradiating the frozen food with the high frequency is configured to be set by the operator with a timer. Furthermore, after the inside of the container holding the food is sealed, the atmospheric pressure inside the container is reduced to a preset pressure by a vacuum pump, and the food in the container is irradiated with a high frequency. Is configured.

During the thawing work, the atmospheric pressure in the container is reduced so that the boiling point of the water in the container is lowered to a set temperature, and the temperatures of ice and water contained in the food rise to normal temperatures. Before, the ice and water vaporize to steam at the set temperature, so the food is well thawed without being altered by heating. Further, when the atmospheric pressure in the container increases due to the generation of water vapor accompanying thawing, the boiling point of water rises, so the vacuum pump is controlled to reduce the atmospheric pressure again.

In the above-mentioned method, the boiling point of water in the closed container is lowered by the reduced pressure, and the melted water is easily evaporated. Therefore, if the microwave irradiation is continued even after the water is melted, a large amount of water evaporates and fills the inside of the container to form dew on the inner wall surface of the container.

The vacuum defroster does not reduce the pressure in the container,
When used under atmospheric pressure, it can be used as a normal microwave oven. Thus, when it is used as a microwave oven as a normal cooking device, much more steam is generated from foods than in thawing work, and much dew condensation is generated in the container.

[0007]

However, after the thawing work and the heating and cooking are completed, the container is closed again to thawing the next frozen body, and the air in the container is exhausted to a predetermined pressure. Because the boiling point of water decreases due to reduced pressure,
The water that has condensed on the inner wall surface of the closed container is re-evaporated and becomes steam, which increases the pressure inside the closed container. Therefore, it takes more time than the first thawing work to reduce the air pressure in the closed container to a predetermined pressure. In addition, in order to save the time, there is a problem that it is necessary to wipe off the water adhering to the inner wall surface of the container once the thawing work is completed.

The present invention has been made to solve the above-mentioned problems, and in a vacuum thawing device for thawing a frozen body stored in a depressurized container by irradiating it with microwaves, It is an object of the present invention to provide a vacuum thawing device which is easy to use and has good working efficiency even if water vapor generated during thawing work or during cooking is condensed in the container.

[0009]

In order to achieve this object, a vacuum thawing apparatus according to claim 1 of the present invention comprises a vent hole provided in a closed container, a lid capable of sealing the vent hole, and a vent hole. And a leakage prevention means for preventing microwave leakage.

Further, in the vacuum thawing apparatus according to the second aspect, the lid driving means for opening and closing the lid, the atmospheric pressure detecting means for detecting the atmospheric pressure in the closed container, and the lid driving means are controlled based on the detected atmospheric pressure. And a control means for controlling.

Further, in the vacuum thawing apparatus according to the third aspect of the present invention, the hermetically sealed container is provided with a large number of ventilation holes formed so as to block microwaves.

[0012]

In the vacuum thawing apparatus according to the first aspect of the present invention having the above structure, when the lid is opened, the air outside the closed container can flow into the closed container through the ventilation hole. When the lid is closed, the air outside the closed container cannot flow into the closed container.

In the vacuum thawing apparatus according to the second aspect, the lid driving means opens and closes the lid. The atmospheric pressure detecting means detects the atmospheric pressure in the closed container. The control means automatically controls the lid driving means based on the detected atmospheric pressure.

Further, in the vacuum thawing apparatus according to the third aspect, the microwave radiated into the closed container is blocked by the shape of the ventilation hole.

[0015]

EXAMPLE First, the principle of thawing will be described. For example, if the pressure is reduced to 3.9 KPa (30 Torr), water will be about 2
Boil at 9 ° C and maintain this boiling point as long as water is present. That is, when the pressure in the closed container 1 is reduced to 3.9 KPa, the object to be thawed is thawed while being maintained at a temperature of about 29 ° C. or less, which is particularly suitable for thawing raw food.

An embodiment of the present invention will be described below with reference to the drawings.

As shown in the schematic block diagram of the present invention in FIG.
A closed container 1 having a door 3 and a pressure reducing device (for example, a vacuum pump) 8 are housed in a frame, and a microwave generator (for example, magnetron) 5 is provided in the closed container 1 through a waveguide.
Are connected, and the space between the closed container 1 and the waveguide is sealed by a plate-shaped partition plate 4 having high radio wave transmission. Further, the closed container 1 is provided with a pressure detecting device 9 so that the degree of vacuum inside can be measured. Further, a vacuum pump 8 is communicated with the closed container 1, and a vacuum exhaust valve 6 is provided in the communication part. With the above apparatus, the frozen container 2 of foods such as seafood and meat can be thawed by irradiating the closed container 1 with microwaves.

The closed container 1 is made of stainless steel,
Vent holes 10 are provided. The ventilation holes 10 are, for example, circular through holes having a diameter of about 2 mm, which are provided in a grid pattern with a pitch of about 5 mm and about 30 mm square. Since the microwave having a wavelength of about 12 cm is used in this embodiment, the vent hole 10 is formed to have a sufficient electromagnetic shielding property.

As shown in the detailed mechanism view of FIG. 2, the ventilation lid 1
An elastic material 12 such as urethane rubber is provided on the side of the surface which contacts the ventilation hole 10 in order to have a hermeticity.
The support 18 is installed outside the upper part of the closed container 1, and the fulcrum 1
5, a linear motion device (for example, an electromagnetic solenoid) 17 is installed. The arm 11-1 of the ventilation lid 11 is installed at a fulcrum 15 so as to be rotatable on a plane parallel to the paper surface of FIG.

The hook 11-2 at the end of the arm 11-1 is connected to the shaft 19 of the linear motion device 17 via the connecting body 16. The linear motion device 17 pulls in the shaft 19 by being driven by an electromagnetic force or the like. When the drive of the linear motion device 17 is released, the tension of the coil spring 14 causes the arm 11-
1 is rotated in the direction of pulling out the shaft 19, and the lid 11 closes the vent hole 10. The length of the connecting body 16 is the linear motion device 17
Is driven and the shaft 19 is retracted, the hook 11
It is adjusted so that the vent hole 10 can be opened by pulling -2 to lift the vent lid 11.

When the air pressure in the closed container 1 decreases, the ventilation lid 1
1 is sucked toward the inside of the closed container 1, and the tightness is further increased.

The mechanical control method during the thawing work by the vacuum thawing apparatus of this embodiment will be described with reference to the timing chart of FIG.

Defrosting starts from T0. At T1, the pressure is reduced to P0 and the vacuum exhaust valve 6 is closed. As the thawing proceeds, the melted water evaporates and the pressure in the closed container 1 starts to rise. When the amount of water vapor is large, water is condensed on the inner wall of the closed container 1. When the pressure in the closed container 1 rises, the boiling point rises, and when it exceeds a certain allowable range, it hinders good thawing of food. Therefore, when the pressure reaches P1, it is judged that a large amount of water vapor has been generated, and the vacuum release valve 6 is opened again by the signal of the pressure detection device 9. T2-T
During the evacuation of 3, the microwave generator 5 is stopped to stop the microwave irradiation, thereby suppressing the generation of water vapor and shortening the depressurization time of T2-T3.

Then, when the pressure returns to the predetermined pressure P0, the vacuum exhaust valve 6 is closed, the microwave irradiation is started again, and the thawing is continued. The thawing work is completed at a predetermined time T6. When the microwave is stopped and the vacuum release valve 7 is opened to return the atmospheric pressure to the atmospheric pressure, the vacuum exhaust valve 6 and the ventilation lid 11 are opened by the signal of the pressure detection device 9 at T5, and the vacuum release valve 7 is closed. The air inside the closed container 1 is discharged by the decompression device 11, and at the same time, a large amount of fresh air flows in from the ventilation hole 10. The air outside the vacuum release valve 7 flows in, but this is very small compared with the air holes 10. As a result, the inside of the closed container 1 is in a so-called ventilation state. The dry new air outside the closed container 1 is passed through the closed container 1 to re-evaporate (vaporize) the water condensed on the inner wall. At T6 when the time for sufficient drying and ventilation has elapsed, the pressure reducing device 8 is switched off, and the vacuum exhaust valve 6 is closed to enter the initial state.

Next, a mechanical control method at the time of heating and cooking by the vacuum thawing apparatus of this embodiment will be described with reference to the timing chart of FIG.

Cooking is started from T10. The microwave generator 5 is activated and microwave heating is started. At the same time, the vacuum exhaust valve 6 is opened to operate the decompression device 8. The vent hole 10 remains open in the initial state. Although the predetermined cooking is completed at T11, the decompression device 8 continues to operate until T12 when a sufficient time has elapsed. T10 to T12
Until then, the decompression device 8 continues to discharge the air in the closed container 1. A large amount of outside air flows in through the ventilation holes 10. T10
During the cooking from T11 to T11, a large amount of steam is usually emitted from the food. Therefore, the air in the closed container 1 becomes extremely humid. The decompression device 8 discharges this high-humidity air and ventilates it with fresh, fresh air outside. This prevents water vapor generated from the food during heating and cooking from condensing on the inner wall of the closed container 1.

As is apparent from the above description, according to the vacuum thawing apparatus of the present embodiment, after the thawing work is completed, the moisture condensed on the inner wall of the closed container 1 is automatically dried, and
Ventilate the air in the closed container 1 that has become high in humidity due to water vapor generated from food when the defrosting device is used as a normal microwave oven to prevent dew condensation on the inner wall of the closed container 1. You can As a result, there is no need to wipe off the dew condensation water on the inner wall of the closed container 1 after the thawing work or the heating and cooking, and thus the usability is good, and even in the re-thawing work, the time required for decompression can be kept almost the same as the first time. The work efficiency is good.

When performing vacuum thawing, the vent hole 10 is used.
Is provided on the side opposite to the position where the worker stands (on the side of the door 3), so that the worker's clothes, hair, etc. are prevented from being sucked and the ventilation hole 10 is prevented from being clogged. In addition, the ventilation hole 10 is provided on the side opposite to the position where the worker stands, and after using the device as a normal microwave oven to stop all functions, a high-humidity gas due to heating is applied to the worker. Since this does not occur, it is possible to prevent the operator from feeling uncomfortable.

In this embodiment, the microwave is blocked by the shape of the ventilation hole 10, but the microwave may be blocked by filling the ventilation hole 10 with steel wool or the like. Further, the ventilation hole 10 may be provided with a filter for removing dust in the air to prevent dust from entering the closed container 1.

Further, a cover may be provided in the vent hole 10 for preventing suction. Further, the vent hole 10 may be formed obliquely so that the high-humidity gas is exhausted rearward.

[0031]

As is apparent from the above description, according to the vacuum thawing apparatus of the first aspect of the present invention, the air outside the closed container flows into the closed container to cause dew condensation in the closed container. Since the water vaporizes, the time and effort required for wiping the inside of the closed container are reduced, the usability is improved, the heating time is prevented from being extended, and the work efficiency is improved.

Further, according to the vacuum thawing apparatus of the second aspect, the lid is opened and closed based on the atmospheric pressure, so that anyone can easily perform good thawing, and the lid driving means saves labor and automation. Is being pursued.

Further, according to the vacuum thaw device of the third aspect, since the microwave is blocked by the shape of the vent hole, the structure of the vacuum thaw device is simple.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the structure of a vacuum defroster.

FIG. 2 is a detailed view of the mechanism of the ventilation lid.

FIG. 3 is a timing chart when performing a thawing operation with a vacuum thawing device.

FIG. 4 is a timing chart when heating and cooking with a vacuum thawing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Airtight container 2 Frozen body 3 Door 5 Microwave generator 6 Vacuum exhaust valve 7 Vacuum release valve 8 Pressure reducing device 9 Pressure detection device 10 Vent hole 11 Vent cover 12 Resilient material 18 Support stand 19 Shaft

Claims (3)

[Claims] 1. A vacuum defrosting device for heating a defroster by irradiating the inside of a closed container with a decompressed state and irradiating the inside of the closed container with a microwave, wherein: A vacuum thawing device comprising: a sealable lid. 2. A lid driving means for opening and closing the lid, an atmospheric pressure detecting means for detecting an atmospheric pressure in the closed container, and a control means for controlling the lid driving means based on the detected atmospheric pressure, The vacuum thawing device according to claim 1, wherein the frozen body stored in the closed container is heated in a predetermined atmospheric pressure range. 3. The vacuum thawing apparatus according to claim 1, wherein a plurality of the vent holes are formed in the closed container so as to block microwaves.