JPH09138055A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent quality of stored foods stored in a temperature range of 0 deg.C to -5 deg.C such as frozen fresh meat and marine fish or the like, in particular, from being deteriorated. SOLUTION: Either a part of or all of a low temperature chamber 11 is applied as an electrical field processing chamber 12. This processing chamber 12 is provided with a high voltage electrode 24, a flat-plate opposing electrode 25 arranged in opposition to the high voltage electrode 24 and a high voltage power supply 26. An electrical field processing is carried out during a period ranging from storing foods to a time until an inner side of the electrical field processing chamber 12 is cooled down to 0 deg.C or less under an operation of a food storing sensor means 28 and an operation of a temperature sensing means 31, thereby a refrigerator in which no freezing occurs in a temperature range of 0 deg.C to -5 deg.C can be attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator having a high-voltage treatment function for improving the storage quality of foods, particularly fresh meat and aquatic seafood.

[0002]

2. Description of the Related Art In recent years, as a method for maintaining the freshness of foods such as fresh meat and seafood in a household refrigerator,
+1 for chilled temperature zone, ice temperature zone, partial temperature zone, etc.
New temperature zone chambers in the temperature range of -3 ° C have been proposed and are increasingly stored.

Further, it is said that if the food is preserved in a temperature zone on the verge of freezing, as described in the phrase "age aging on ice," the taste will be improved. For example, as described in JP-A-7-115952, Vegetables, fruits, grains, nuts,
Living organisms of breathing foods such as live fish and shellfish are stored in a low temperature range of 0 ° C or lower, and stress treatments such as drying, watering, pressure, light rays, snow, and sound waves are given individually and in combination. Then, a method has been proposed in which various umami-related components are produced and secreted in the living body of foods so that immature ones are matured and non-seasoned ones are made into seasonal tastes to improve the umami.

It is well known that fresh foods and foods such as aquatic fish and shellfish can suppress the activity of bacteria and maintain their freshness at lower temperatures.
Frozen storage below 5 ° C is required. However, when the food temperature is below the freezing point, the food is frozen, and when the food is frozen, there is a problem that the cell membrane is destroyed and the taste is deteriorated.

Therefore, when the frozen treatment is carried out, the water in the food becomes ice and the crystals become large, so that the maximum ice crystal formation zone -1.
Quick freezing should be attempted to pass through -5 ° C to -5 ° C as soon as possible. However, in a domestic refrigerator, there is a limit to quick freezing, and it is difficult to completely eliminate cell destruction. Therefore, if it will be eaten after a few days, it is appropriate to store it in the new temperature zone chamber. The storage in the new temperature zone saves the thawing work and does not freeze, so there is no crystal growth and cell destruction. It can be said that it is preferable as a method for preserving fresh foods without the risk of.

Further, a refrigerator having a high voltage processing function is disclosed in Japanese Patent Laid-Open No. 257867/1990. However, frozen foods are applied with an anion by a high-voltage induction electrostatic method to obtain a refrigerator at 3 ° C to -3 ° C. A method of thawing within temperature has been proposed.

The following has been proposed in Japanese Patent Laid-Open No. 2-25.
A method for thawing food in a refrigerator disclosed in Japanese Patent No. 7867 will be described.

FIG. 6 is a longitudinal sectional view of a conventionally proposed refrigerator, 1 is a high voltage power source, 2 is a refrigerator, 3 is an inner box, 4 is a heat insulating material, 5 is a frozen product, and 6 is a refrigerator. . The secondary side one pole of the high voltage power source 1 is insulated, and only the other one pole is connected to the electrically conductive inner box 3 made of stainless steel or the like so that negative electrons by electrostatic induction can be applied. At that time, the interior 6 and the shelves are connected by a clasp and are in a conductive state. The secondary voltage of the high voltage power supply 1 is designed to be 5 kV to 20 kV.

In the refrigerator constructed as described above,
The defrosting method will be described below. First, the temperature of the interior 6 is set to a predetermined temperature of 3 ° C to -3 ° C, the frozen product 5 to be thawed is placed on the shelf, and the switch (not shown) of the high-voltage power supply 1 is turned on to start the thawing. . The frozen product 5 can be quickly and evenly thawed by receiving an anion electron due to electrostatic induction. In addition, the sterilizing effect is excellent and the drip amount can be reduced.

[0010]

However, in an actual refrigerator, it is very difficult to stably cool within ± 0.5 ° C. in the temperature range of the new temperature zone. The surface of the food is warmed above the set temperature or cooled below the set temperature by the temperature rise due to the opening and closing of the door and the introduction of cooling air for pulling down, and at least the target set temperature is about ± 2.
Variation of ℃ or more occurs.

That is, even in the chilled or ice temperature range where foods such as fresh meat and seafood are not frozen, the partial temperature range is aimed at partial freezing where ice crystals do not grow. However, it is very difficult to uniformly control the temperature before and after the freezing point. Especially, the temperature change on the surface of the food is remarkable, and there is a high possibility that the surface of the food freezes and crystals grow.

Further, in the structure of the refrigerator to which the high electric field is added as described above, the inner box 3 of the refrigerator needs to be made of a metal material such as stainless steel, which increases the cost. Also,
The effect disappears when an anion is not directly applied to the frozen product 5. Therefore, in order to bring out the effect, it is necessary to bring the frozen product 5 into contact with the inner box 3 and to continuously energize during thawing. It consumes power and is not easy to handle safety.

Further, even if the frozen product 5 is put in a plastic container having no electrical conductivity and thawed, the effect cannot be exhibited. Therefore, the conventional method of thawing in a refrigerator having a high-voltage processing function has various restrictions and has a problem of poor usability.

In view of the above problems, the present invention does not directly apply an anion electron to a frozen product, but a high-voltage electrode, a flat plate counter electrode arranged to face the high-voltage electrode, and a high voltage to the high-voltage electrode and the flat plate counter electrode. It has a high-voltage power supply to add water, and the water in the food is temporarily oriented by energizing the high-voltage power supply during the period from the storage of food to the time when the electric field treatment chamber is cooled to 0 ° C or less. The temperature of food is temporarily reduced to -5 by using combined water.
The object is to provide a refrigerator that does not freeze even when the temperature reaches ℃.

[0015]

In order to achieve this object, the refrigerator of the present invention uses an electric field treatment chamber in a part or the whole of a low temperature chamber whose temperature changes from 0 to -5 ° C. and a high voltage electrode in the treatment chamber. , A flat plate counter electrode arranged opposite to this, and having a high voltage power source for applying a high voltage to the high voltage electrode and the flat plate counter electrode, by means of food storage detection means and temperature detection means in the electric field treatment chamber,
The high-voltage power supply is energized during the time period from when the food is stored until the electric field treatment chamber is cooled to 0 ° C or less.

Further, a switch interlocking with the opening and closing of the door of the electric field processing chamber is provided, and the drive of this switch is used as a food storage detecting means. Furthermore, when the door of the electric field processing chamber is in an open state, the high voltage power supply is not energized. The control means is provided, the high voltage range is set to 1 KV or more, and the high voltage electrode and the inner wall surface of the electric field treatment chamber are insulated so that the electric capacity does not exceed 1 mW / cm 2 even if the electric field treatment chamber is filled with a conductive substance. .

The high-voltage power source is a commercial frequency (50/60 Hz) n-type, and the high-voltage electrode side is the upper surface and the flat plate counter electrode is the lower surface. It has a plurality of needle-shaped portions that project toward each other.

If the temperature detecting means in the electric field processing chamber is a fluorescent optical fiber thermometer or a thermocouple type thermometer is used, the electric field processing chamber is cooled to 0 ° C. or less from the time of storing the food. The energization of the high-voltage power supply during the period up to this time is intermittent operation, and the temperature detecting means in the electric field processing chamber is performed only when the energization is stopped.

With the above-mentioned constitution, the temperature of the food can be controlled by temporarily directing the water in the food by the high electric field treatment without being restricted by the packaging condition of the food or the kind of the container and changing the free water to the bound water. Provide a refrigerator that does not freeze even when it temporarily becomes -5 ° C. As a result, the cells are not destroyed, the freshness can be maintained by low-temperature storage, and the frozen food can be stored without impairing the taste of the food, thus improving the quality.

Further, a switch interlocking with the opening and closing of the door of the electric field processing chamber is provided, and the electric field can be automatically processed by energizing the high-voltage power supply only when the storage of food is detected, which is convenient. Furthermore, when the door of the electric field processing chamber is in an open state, a control means is provided so as not to energize the high voltage power supply, and the range of high voltage is set to 1 KV or more, and even if the electric field processing chamber is fully loaded with an electrically conductive substance, the electric power is not generated. Capacity is 1mW / cm
The high-voltage electrode is insulated from the wall surface of the electric field treatment chamber so that it does not exceed 2, and the high-voltage electrode side is the top side and the flat plate counter electrode is the bottom side, so that you can avoid electric shock due to falling of water or foreign matter. It can be prevented and safety can be secured in double or triple.

By using n times the frequency of the commercial power supply (50/60 Hz) as the high-voltage power supply, it is possible to make a small-sized and low-cost power supply. Further, the high-voltage electrode has a flat plate shape and has a plurality of needle-shaped portions protruding toward the counter electrode, so that the electric field density in the electric field treatment chamber can be stably obtained on average.

Further, by using a fluorescence type optical fiber thermometer as the temperature detecting means in the electric field processing chamber, malfunction due to the electric field can be eliminated. In addition, the high-voltage power supply should be energized intermittently during the period from when the food is stored to when the electric field processing chamber is cooled to 0 ° C or less, and the temperature detection means in the electric field processing chamber is operated only when the energization is stopped. You can use thermocouples and resistance thermometers to eliminate malfunctions due to electric fields.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION According to the first aspect of the present invention, a part or all of a low temperature chamber whose temperature is controlled to 0 to -5 ° C is used as an electric field treatment chamber, and a high voltage electrode is provided in the treatment chamber. And a high-voltage power source for applying a high voltage to the high-voltage electrode and the flat-plate counter electrode, which are arranged so as to face each other, and the electric field treatment from the time of food storage by the food storage detection means and the temperature detection means in the electric field processing chamber. High-voltage power is supplied to the room until the room is cooled to 0 ° C or less. The water in the food is temporarily oriented by the high electric field treatment, and the free water is changed to combined water to change the food temperature. It has the effect of not freezing even when it temporarily becomes -5 ° C.

According to the second aspect of the present invention, a switch interlocking with the opening and closing of the door of the electric field processing chamber is provided, and the drive of this switch is used as food storage detecting means. It has the effect of automatically detecting the start of the electric field processing, as well as the storage detection.

According to the third aspect of the present invention, the control means is provided so as not to energize the high-voltage power supply when the door of the electric field processing chamber is in an open state, and is interlocked with the opening and closing of the door of the electric field processing chamber. By using the switch, the control means can be provided and the safety can be easily ensured.

In the invention according to claim 4, the high voltage range is set to 1 KV or more, and the electric capacity does not exceed 1 mW / cm 2 even if the electric field treatment chamber is fully loaded with a conductive substance. Since the wall surface is insulated, the safety mechanism described in claim 3 does not work, and even if a part of the body touches the electric field treatment chamber, it does not affect the human body. .

According to the invention of claim 5, the frequency of the high-voltage power supply is n times as high as the commercial frequency (50/60 Hz), and the control circuit is simple, and the power supply is small in size and low in cost. is there.

According to a sixth aspect of the present invention, the high-voltage electrode side is the upper surface and the flat plate counter electrode is the lower surface, and the flat plate counter electrode is grounded. It acts so as not to cause a short circuit of a high voltage due to a drop of water or food. It is a thing.

According to a seventh aspect of the present invention, the high-voltage electrode is formed in a flat plate shape and has a plurality of needle-shaped portions projecting toward the counter electrode. Even if it exists, it acts so as to obtain a relatively stable voltage density.

According to the eighth aspect of the invention, the temperature detecting means in the electric field treatment chamber is a fluorescent optical fiber thermometer, and when a side resistor type thermometer or a thermocouple type thermometer is used, the structure thereof is used. Fluorescent optical fiber that makes accurate temperature measurement difficult because the metal that is the body is significantly affected by high electric fields.
If it is a thermometer, it does not use metal and acts so as not to be affected by a high electric field.

According to a ninth aspect of the present invention, the high-voltage power supply is energized intermittently during the period from the time when the food is stored until the electric field processing chamber is cooled to 0 ° C. or less, and the temperature detecting means in the electric field processing chamber is detected. Is performed only when the power supply to the power supply is stopped.Temporarily stopping the generation of the high electric field and measuring the temperature during that time will not affect the high electric field even if the thermometer is relatively versatile. It has the effect that it can be measured.

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4. FIG. 1 is a cross-sectional view of an electric field treatment chamber provided in a part of a low temperature chamber which is a new temperature zone showing an embodiment of the present invention. FIG. 2 is an overall cross-sectional view of a household refrigerator having a low temperature room. FIG. 3 is a flow chart showing the operation of the fluorescent optical fiber thermometer of the embodiment, and FIG. 4 is a flow chart showing the operation of the resistance thermometer and thermocouple thermometer of the embodiment. FIG. 5 is a cross-sectional view of the high electric field processing device section taken out.

Reference numeral 7 is a refrigerator showing an embodiment of the present invention.
It is composed of a freezing room 8, a refrigerating room 9, a vegetable room 10, and an electric field processing room 12 provided in a part of the low temperature room 11 in the new temperature zone. Each chamber has doors 13, 14, 15, 16, and 17 and forms a closed space 19 surrounded by a heat insulating box 18 of the main body. Reference numeral 20 is an air passage, 21 is a heat exchanger, 22 is a fan for sending cool air to each chamber, and 23 is a compressor.

In the electric field treatment chamber 12, a high voltage electrode 24 is provided on the top surface, and a flat plate counter electrode 25 made of metal such as copper, aluminum or stainless steel is provided on the bottom surface. And about 1 on the back
A high voltage power supply 26 of 0 kV is provided, and the high voltage power supply 26, the high voltage electrode 24 and the flat plate counter electrode 25 are connected by a high voltage electric wire 27. A switch 28 that contacts the door 17 is arranged on the side wall of the electric field processing chamber 12 so that the high-voltage power supply 26 can be energized only when the door 17 of the electric field processing chamber 12 is closed. I have set up. In addition, the electric field treatment room 12
A fluorescent optical fiber-thermometer 29 is arranged on the side wall of the.

Reference numeral 30 denotes a food storage detection means, which makes a determination by opening / closing the door 17 of the electric field processing chamber 12 in response to a signal from the switch 28. Reference numeral 31 denotes a temperature detecting means in the electric field processing chamber, which accurately determines the temperature in the electric field processing chamber according to a signal from the fluorescent optical fiber thermometer 29. Also, 32
Is a CPU as a time control means, which is operated by a program stored in a storage circuit (not shown) as is well known. The output signal from the food storage detection means 30, the temperature detection means 31, and the time control means 33 causes The energization of the high voltage power supply 26 is controlled.

The high voltage electrode 24 is made of copper, like the plate counter electrode 25.
A flat plate made of metal such as aluminum or stainless steel is used, and a needle-like protrusion 34 is provided to stabilize the electric field density on the plane. Further, the electric capacity Q when the electric field processing chamber 12 is filled with a conductive substance is 1 per square centimeter.
Insulating material 35 on the surface of high-voltage electrode 24 so as to be 0 mW or less
Is adjusted by.

In the electric field processing chamber 12, the cold air flowing through the ventilation passage 20 is sent to the electric field processing chamber 12 by the open / close control of the electromagnetic damper 36, and the indoor temperature is controlled to -3 ° C. on average, but the surface temperature of the food is It varies from 0 ° C to -5 ° C.

Regarding the refrigerator constructed as described above,
The operation will be described with reference to FIGS. 1 to 5.

First, when the purchased food (meat, seafood, etc.) 37 is stored in the electric field processing chamber 12 by opening the door 17 of the electric field processing chamber 12, a signal from the switch 28 is read to read the signal from the door 17. The open / closed state is determined (step S
1). If the door 17 is in the open state, the CPU 32 keeps the relay (not shown) of the high-voltage power supply 26 in the open state and keeps the high-voltage power supply 26 off (step S).
2).

When the door 17 is closed, it is determined that the food 37 is stored and the food storage detecting means 30 is activated (step S3), and then the fluorescent optical fiber thermometer 29.
The signal from the sensor is read, and if the temperature is 0 ° C. or higher, the temperature detecting means 31 turns on the high-voltage power supply 26 (step S
4). If after opening the door 17 and closing the door 17 again without inserting anything for some reason, the temperature inside the refrigerator will be 0 ° C.
If it does not rise above the above level, the CPU 32 keeps the high-voltage power supply 26 in the OFF state as it is (step S4).

When the temperature is 0 ° C. or higher, the time control means 33
Therefore, the electric field process is continued until 20 minutes is detected (step S7) or the temperature detecting means 31 detects 0 ° C. or lower (step S6).

When a new food 37 is stored, the temperature of the normal electric field processing chamber 12 rises, so the temperature detecting means 31 judges that the temperature is 0 ° C. or higher, and the CPU 32 turns on the relay (not shown) of the high voltage power supply 26, High voltage electrode 24 for 10 hours
When a high voltage of kV is applied, a high electric field is formed in the space between the high voltage electrode 24 and the flat plate counter electrode 25, and the food 37 is subjected to electric field treatment (note that regarding the electric field treatment of food, "Science Asahi" 1984). , July issue).

Regarding the confirmation of the freezing point depression due to the electric field treatment, 48 small plastic cells were filled with 2% of agar and cut fish meat, and a high voltage power supply 26 of 10 KV was used to make a gap between the high voltage electrode 24 and the flat plate counter electrode 25. The electric field treatment chamber 12 of 5 mW / cm 2 was formed, and the 48 cells were placed on the bottom surface of the electric field treatment chamber 12 corresponding to the upper part of the flat plate counter electrode 25, and the electric field treatment was performed for 20 minutes. −
It was left for about 2 to 3 days until it became stable at 3 ° C., and it was confirmed whether or not the food in the cell was frozen. Whereas those treated with an electric field did not freeze, whereas those not treated with an electric field showed some freezing around the spout of cold air.

The electric field treatment time is sufficient for 10 to 20 minutes, but the electric field treatment at 0 ° C. or lower results in faster freezing. Although the proof of principle for this result has not been clarified, the polarization of water molecules increases due to the electric field treatment, and the water molecules of free water in the food combine with the food tissues such as cells and nutrients in the food to become bound water, which makes it difficult to freeze. Is interpreted as
If the temperature is 0 ° C. or lower in the state of being treated with an electric field, freezing may occur due to accelerated ice nucleation, and the treatment at 0 ° C. or lower is not appropriate.

Therefore, the electric field processed food 37 is
Since it does not freeze when the temperature changes from 0 to -5 ° C, it is possible to maintain freshness at low temperatures and prevent the umami from flowing out due to cell destruction due to freezing.

Further, the switch 28 is closed only after the door 17 of the electric field processing chamber 12 is closed, and the high voltage power supply 26 can be energized only in that state, so that the safety is high.

The high-voltage power supply 26 may be DC or AC, but the frequency of the high-voltage power supply 26 is the commercial frequency (50/6).
The number of parts can be reduced and the power source can be made compact and low-cost by setting it to n times of 0 Hz).

The food storage detecting means 30 and the temperature detecting means 31 in the electric field processing chamber can automatically process the electric field of the food 37 for a predetermined time only by putting the food in the electric field processing chamber 12, which is convenient. .

Further, unlike the conventional method, since there is no restriction on the packaging state of the food 37 and the type of container, even if the food 37 is stored while being placed on a plastic or ceramic dish having no electrical conductivity, The effect of various electric field treatment appears. Furthermore,
Since it is not necessary to make the inner wall of the electric field processing chamber 11 entirely of a metallic material such as stainless steel, the cost is lower than that of the conventional method.

In the above description, the voltage of the high voltage power source 26 is 10 kV and the electric capacity is 5 mW / cm @ 2. However, the voltage of the high voltage power source 26 is 1 kV or more and the electric capacity is 0.1 mW / cm @ 2. If it is above, there is an antifreezing effect.

However, judging from the safety of radio waves, 10 mW
It is necessary to keep the pressure below 10 cm2 / cm2. For that purpose, an insulating material 29 is formed on the surface of the high-voltage electrode 24, and even if food 37 is packed in the electric field treatment chamber 12, it is 10 m.
It is set to W / cm2 or less.

The same effect can be obtained even if the high voltage electrode 24 and the flat plate counter electrode 25 are arranged upside down and the food 37 is placed on the high voltage electrode 24 for electric field treatment.
By arranging the flat plate counter electrode 25 on the lower surface side and providing an earth, it is possible to avoid the influence on the human body due to a short circuit due to the intrusion of water or food into the flat plate counter electrode 25. Can be secured.

FIG. 4 shows a control flowchart when a thermometer such as a resistance thermometer or a thermocouple thermometer which is influenced by an electric field is used as the temperature sensor of the temperature detecting means 31.

Up to step S4, it is the same as when the fluorescent optical fiber thermometer shown in FIG. 3 is used, but the time control means 33 operates so as to stop the high voltage power supply 26 at intervals of 2 minutes (step). S7). After that, if the temperature detecting means 31 determines that the temperature is 0 ° C. or higher, the high voltage power supply 26 is turned on again and the process is repeated from step S5. Whether the temperature detecting means 31 determines 0 ° C. or lower, or the repeating cycle from step S5 is 1
When it reaches 0 times, the high voltage power supply is stopped.

Although the high-voltage power supply 26 is stopped at intervals of 2 minutes and completed by repeating 10 times as an embodiment, the numerical value is not limited, and high voltage is supplied at intervals of 1 minute. The effect is the same if the electric field treatment time of the total is about 10 to 20 minutes or more, for example, by stopping and repeating 20 times.

[0056]

As described above, the refrigerator according to the present invention has a temperature of 0 to -5.
A part or all of the low temperature chamber whose temperature is adjusted to ℃ is used as an electric field treatment chamber, a high voltage electrode, a flat plate counter electrode arranged opposite to the high voltage electrode, a high voltage is applied to the high voltage electrode and the flat plate counter electrode. An additional high-voltage power supply is provided, and the high-voltage power supply is energized only during the period from when food is stored to when the temperature of the electric field treatment chamber is cooled to 0 ° C. or less by the food storage detection unit and the temperature detection unit in the electric field treatment chamber. .

Further, a switch interlocking with the opening and closing of the door of the electric field processing chamber is provided, the drive of this switch is used as a food storage detecting means, and the high voltage power supply is not energized when the door of the electric field processing chamber is open. A control means is provided, the high voltage range is set to 1 KV or more, and the high-voltage electrode and the wall surface of the electric field treatment chamber are insulated so that the electric capacity does not exceed 10 mW / cm 2 even if the electric field treatment chamber is fully loaded with a conductive substance. .

The frequency of the high-voltage power supply is n times the commercial frequency (50/60 Hz), and the high-voltage electrode side is the upper surface and the flat plate counter electrode is the lower surface. It has a plurality of needle-shaped portions that project toward each other.

If the temperature detecting means in the electric field processing chamber is a fluorescent optical fiber thermometer or a thermocouple type thermometer is used, the electric field processing chamber is cooled to 0 ° C. or less from the time of storing food. The energization of the high-voltage power supply during the period up to this time is intermittent operation, and the temperature detecting means in the electric field processing chamber is performed only when the energization is stopped.

Therefore, the temperature inside the electric field treatment chamber is 0 ° C. from the time when the food is stored, without being restricted by the packaging condition of the food and the type of container.
By energizing the high-voltage power supply during the time until it is cooled to a high electric field for a short time, the water in the food is temporarily oriented, and the free water is combined with the food tissue to change the food temperature. Provide a refrigerator that does not freeze even when the temperature reaches -5 ° C. As a result, even if the food surface temperature fluctuates at 0 ° C to -5 ° C, it does not freeze, there is no destruction of cells, and it is possible to maintain the freshness by low-temperature preservation and unfrozen storage that does not impair the taste of the food and preserve it. The quality of food can be improved.

Further, by providing a switch interlocking with the opening and closing of the door of the electric field processing chamber and energizing the high voltage power supply only when the storage of food is detected, the electric field can be processed automatically, which is convenient. Furthermore, when the door of the electric field processing chamber is in an open state, a control means is provided so as not to energize the high voltage power supply, and the range of high voltage is set to 1 KV or more, and the electric capacity is obtained even if the electric field processing chamber is loaded with a conductive substance. Is insulated from the high-voltage electrode and the wall surface of the electric field treatment chamber so that it does not exceed 10 mW / cm2. Also, by keeping the ground with the high-voltage electrode side as the upper side and the flat plate counter electrode as the lower side, water or foreign matter may fall. The electric shock can be prevented and the safety can be doubled or tripled.

By using n times the frequency of the commercial power supply (50/60 Hz) for the high-voltage power supply, it is possible to make a small-sized and low-cost power supply. Further, the high-voltage electrode has a flat plate shape and has a plurality of needle-shaped portions protruding toward the counter electrode, so that the electric field density in the electric field treatment chamber can be stably obtained on average.

Further, by using a fluorescence type optical fiber thermometer as the temperature detecting means in the electric field processing chamber, malfunction due to the electric field can be eliminated. In addition, the high-voltage power supply should be energized intermittently during the period from when the food is stored to when the electric field processing chamber is cooled to 0 ° C or less, and the temperature detection means in the electric field processing chamber is operated only when the energization is stopped. You can use thermocouples and resistance thermometers to eliminate malfunctions due to electric fields.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electric field processing chamber provided in a part of a low temperature chamber which is a new temperature zone showing an embodiment of the present invention.

FIG. 2 is an overall cross-sectional view of a household refrigerator having a low temperature chamber according to the same embodiment.

FIG. 3 is a flow chart showing the operation of the fluorescent optical fiber according to the embodiment under temperature control.

FIG. 4 is a flow chart showing temperature control by a resistance thermometer and a thermocouple thermometer of the same embodiment.

FIG. 5 is a cross-sectional view showing a high electric field processing device portion of the same embodiment.

FIG. 6 is a longitudinal sectional view of a conventional refrigerator.

[Explanation of symbols]

 11 Low Greenhouse 12 Electric Field Treatment Room 17 Electric Field Treatment Room Door 24 High Voltage Electrode 25 Plate Counter Electrode 26 High Voltage Power Supply 28 Switch 29 Fluorescent Fiber Optic Thermometer 30 Food Storage Detecting Device 31 Temperature Detecting Device 34 Needle-like Part

Claims (9)

[Claims] 1. A part or all of a low temperature chamber whose temperature is controlled to 0 to −5 ° C. is used as an electric field processing chamber, a high voltage electrode, a flat plate counter electrode arranged opposite to the high voltage electrode, and It has a high-voltage power supply for applying a high voltage to the high-voltage electrode and the flat plate counter electrode, and is the time period from when the food is stored to when the electric field treatment chamber is cooled to 0 ° C or less by the food storage detection unit and the temperature detection unit in the electric field treatment chamber. A refrigerator characterized in that a high-voltage power supply is energized. 2. The refrigerator according to claim 1, wherein a switch interlocking with opening and closing of a door of the electric field processing chamber is provided, and the drive of the switch serves as food storage detecting means. 3. The refrigerator according to claim 1, further comprising control means so as not to energize the high-voltage power supply when the door of the electric field processing chamber is in an open state. 4. The high voltage range is set to 1 KV or more, and the electric capacity is 1 mW / c even when the electric field treatment chamber is fully loaded with a conductive material.
The refrigerator according to claim 1, wherein the high-voltage electrode and the inner wall surface of the electric field treatment chamber are insulated from each other so as not to exceed m2. 5. The frequency of the high voltage power supply is a commercial frequency (50 /
The refrigerator according to claim 1, which has a frequency of 60 Hz) n times. 6. The refrigerator according to claim 1, wherein the high-voltage electrode side is the upper surface, the flat plate counter electrode is the lower surface, and the flat plate counter electrode is the ground. 7. The refrigerator according to claim 1, wherein the high-voltage electrode has a flat plate shape and has a plurality of needle-shaped portions protruding toward the counter electrode. 8. The refrigerator according to claim 1, wherein the temperature detecting means in the electric field processing chamber is a fluorescent optical fiber thermometer. 9. The high-voltage power supply is intermittently energized during the time period from the time when the food is stored until the electric field treatment chamber is cooled to 0 ° C. or less, and the temperature detection means in the electric field treatment chamber is performed only when the energization is stopped. The refrigerator according to claim 1.