JPH1019268A - Defrosting device for frozen food - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize highly efficient and uniform high-frequency defrosting heating employing a surface wave circuit and make the maintenance of the surface wave circuit unnecessary. SOLUTION: A surface wave circuit 8 is attached integrally to the outside lower part of a bottom wall of an evacuated inner box 3 so as to be capable of preventing the invasion of foreign matters by the bottom wall whereby not only highly efficient and uniform heating is permitted but also an evacuated inner box type frozen food defrosting device, excellent in handling property without necessitating any special maintenance of the part of the surface wave circuit 8, can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frozen food thawing apparatus for heating and thawing frozen food under a pressure lower than the atmospheric pressure, and more particularly to a uniform heating function using a surface wave circuit. Thus, the uniform thawing performance of the frozen food is further improved.

[0002]

2. Description of the Related Art An apparatus that places frozen food under a pressure environment lower than the atmospheric pressure and performs thawing heating using high-frequency energy reduces the risk of uneven heating due to the lowering of the boiling point. Has come to the forefront in recent years because it has been realized.

[0003] Such a type of frozen food thawing apparatus has been steadily reduced in size and has been proposed up to a size of a household microwave oven.

[0004]

The advantage of heating under a pressure lower than the atmospheric pressure is that the upper limit of the temperature rise is the boiling point corresponding to the pressure.

Therefore, it has been considered that an abnormal temperature rise does not occur if the pressure is properly managed.

However, when a large amount of water vapor is generated as the temperature rises and the pressure rises, and it becomes difficult to maintain the predetermined pressure by decompression by the vacuum pump, the boiling point rises and an undesired temperature rises. There is a problem that heating is performed in the region.

[0007] In order to avoid this, it was necessary to equip a decompression pump with a higher capacity. As a matter of course, there was a problem that the cost would be extra.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and comprises an oven, a reduced-pressure inner box which is installed in the oven and stores frozen food, and a reduced-pressure inner box. A surface acoustic wave circuit integrally mounted on the lower portion of the bottom wall outside the bottom wall so as to prevent foreign matter from entering, a decompression pump for reducing the air pressure in the decompression inner box, and decompression by the decompression pump. A pressure sensor for detecting the air pressure inside the decompression inner box, an atmosphere return valve for flowing air into the decompression inner box to return the air pressure to the atmospheric pressure, and a magnetron for supplying high-frequency energy into the oven, A setting instruction device that sets and instructs the contents of the thawing heating operation, and drives the decompression pump, atmospheric return valve and magnetron by taking in the signal of this setting instruction device and the pressure sensor You configure the frozen food thawing device and Gosuru control device.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Frozen food is stored and installed in a decompressed inner box, a lid is closed, and a setting instruction device is operated to obtain information necessary for a thawing operation such as an initial temperature, a weight and a finished temperature of the frozen food. When the setting is made and the operation start is instructed, the control device closes the atmosphere return valve and starts driving the pressure reducing pump. When the pressure is reduced and the pressure sensor detects a predetermined pressure, the control device continues to drive the pressure reducing pump to maintain the predetermined pressure and starts driving the magnetron.
Then, high-frequency energy is intensively generated on the upper surface portion of the surface acoustic wave circuit, and the frozen food is heated more efficiently and more uniformly than when no surface acoustic wave circuit is used.

When the predetermined thawing operation is completed, the control device stops the operation of the decompression pump and the magnetron, opens and drives the atmosphere return valve, and allows the atmosphere to flow into the decompression inner box.

Thereafter, it is possible to remove the lid that has closed the inner vacuum box.

[0012]

Embodiments of the present invention will be described below.

In FIG. 1, reference numeral 1 denotes an oven of a frozen food thawing apparatus, 2 denotes an opening and closing door thereof, and 3 denotes an oven 1
This is a decompression inner box made of a high-frequency, low-loss material installed inside. Reference numeral 4 denotes a plate-shaped fish meat frozen food set in the inner box 3. Reference numeral 5 denotes a removable opening / closing lid of the decompression inner box 3, which forms one wall of the decompression inner box 3.
O embedded in the entire periphery of the inner box opening edge
A ring packing 7 is a lid clamp for ensuring that the lid 5 is closed.

Numeral 8 designates a comb-shaped surface wave circuit which is integrally attached to the outer lower part of the bottom wall of the inner box and generates a surface wave on the frozen food side in the inner box 3. It is attached tightly to the outside, and the periphery and the lower part are hermetically sealed so that foreign matter such as food waste does not invade similarly to the upper surface.

Reference numeral 9 denotes a decompression pump, 10 denotes an inner box 3, a decompression pump 9, an intake / exhaust pipe connecting the atmosphere, 11 denotes a pressure sensor attached to the intake / exhaust pipe 10, and 12 denotes an inner box 3.
Atmospheric return valve that opens when returning the internal pressure to atmospheric pressure,
13 is a filter for filtering the air flowing into the atmosphere return valve 12, and 14 is an exhaust port of the pressure reducing pump 9.

Reference numeral 15 denotes a magnetron attached to the oven 1. Reference numeral 16 denotes a setting for setting the initial temperature, weight, finish temperature, contents of the thawing heating operation, the start of the thawing operation, the stop of the frozen food, and other instruction information. An indicating device 17 is a control device for controlling the pressure reducing pump 9, the atmosphere return valve 12, and the magnetron 15 by taking in the signals of the setting indicating device 16 and the pressure sensor 11.

The configuration of the embodiment of the present invention is as described above, and the operation will be described next.

After the frozen food 4 is stored and set in a fixed position in the inner box 3, the lid 5 is put up, and the lid clamp 7 is operated to seal.

When the setting instruction device 16 is operated to set a heating menu (control information of the decompression pump 9 and the magnetron 15 based on the temperature, weight, finish temperature, etc. of the frozen food 4) and start the thawing operation, The control device 17 activates the decompression pump 9 to suck the air in the inner box 3,
The pressure inside the inner box 3 is reduced. When the pressure sensor 11 detects that the pressure has decreased to a predetermined pressure, the control device 1
7 starts the magnetron 15 while controlling the operation of the decompression pump 9 so that a constant pressure is maintained, and starts high-frequency heating of the frozen food.

As a result, surface waves are intensively generated in the space above the surface wave circuit 8 where the frozen food 4 exists, whereby the frozen food 4 is efficiently heated. in the meantime,
The whole area of the frozen food 4 is uniformly heated relatively well, and while the boiling point is lowered by the reduced pressure, the runaway of the temperature rise is suppressed and the food is heated.

When heating is performed under a predetermined pressure for a predetermined time, the control device 17 stops driving the magnetron 15 and the pressure reducing pump 9, opens the atmosphere return valve 14, and releases the atmosphere into the inner box 3. Then, the pressure in the inner box 3 is returned to the atmospheric pressure. Although not described with reference to the drawings, if a display device is provided to notify the progress and end of the thawing operation so that the timing of taking out the food 4 can be grasped, the convenience is further increased. Needless to say.

As described above, since the surface acoustic wave circuit 8 is integrally mounted on the bottom portion of the reduced-pressure inner box 3, high-efficiency heating and uniform heating can be performed, and the wall of the reduced-pressure inner box is further improved. The surface acoustic wave circuit 8 is covered by using a part of the surface acoustic wave circuit 8, so that it is possible to prevent foreign substances from entering the surface acoustic wave circuit 8, and special maintenance of the surface acoustic wave circuit 8 is not required. An excellent decompression inner box type frozen food thawing device was realized.

[0023]

As described above, according to the present invention, high-efficiency heating and uniform heating can be performed, and furthermore, there is no need to worry about invasion of foreign matter into the surface acoustic wave circuit. A food thawing device could be realized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a system according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oven 3 Decompression inner box 5 Lid 8 Surface wave circuit 9 Decompression pump 10 Intake / exhaust pipe 11 Pressure sensor 12 Atmospheric return valve 15 Magnetron 16 Setting instruction device 17 Control device

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Yajima 3-1, Shinjuyo-ji, Kashiwa-shi, Chiba Prefecture Nichi Hometech Co., Ltd. Within Home Tech (72) Inventor Akio Mitomo 3-1, Shinjuyoji 2 Kashiwa-shi, Chiba Prefecture Within Hitachi Co., Ltd. (72) Inventor Makoto Oda 502, Tsuchiura, Tsuchiura-shi, Ibaraki Pref. Hitachi, Ltd. 72) Inventor Yasutaka Noguchi 502, Shinryu, Tsuchiura-shi, Ibaraki, Japan Machinery Research Laboratory, Hitachi, Ltd.

Claims (1)

[Claims] 1. An oven (1), a decompressed inner box (3) installed in the oven and containing a frozen food (6), and a foreign substance formed by a bottom wall at a lower portion of a bottom wall outside the depressurized inner box. A surface acoustic wave circuit (8) integrally mounted so as to prevent intrusion of air, a pressure reducing pump (9) for reducing the air pressure in the pressure reducing inner box, and a pressure reducing pump reduced by the pressure reducing pump. A pressure sensor (11) for detecting the air pressure in the box, an atmosphere return valve (12) for flowing air into the decompression inner box and returning the air pressure to atmospheric pressure, and a high-frequency energy in the oven. (15), a setting instructing device (16) for setting and instructing the contents of the thawing heating operation, and a signal from the setting instructing device and the pressure sensor is taken in, the decompression pump and the atmosphere return are taken in. A frozen food thawing apparatus characterized by comprising a valve and a control device (17) for driving and controlling the magnetron.