JPH10304855A - High frequency heating sterilizer and sterilization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the sterilization treatment of tightly packed food products without damage to the package vessel, as the installation and running costs are minimized. SOLUTION: Tightly sealed packed food products P are sterilized by the dielectric heating with high-frequency power. At this time, the sterilization vessel 2 for receiving the tightly sealed packed food product P and the tightly sealed food product P in the sterilization vessel 2 are equipped with opposing electrodes 20 for feeding high-frequency electric power, while the sterilization vessel 2 is provided with the heating chamber 24 having the inner wall face to contact with the whole outer face of the tightly sealed packed food product P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for sealing various foods in a packaging container such as a plastic bag or tray.
The present invention relates to a high-frequency heat sterilizer and a sterilization method used for heat sterilization of so-called sealed packaged food.

[0002]

2. Description of the Related Art The so-called sealed packaged food in which various foods are sealed in a packaging container such as a plastic bag or tray is remarkable, and the sealed packaged food now plays a considerable part in the diet. is the current situation. Conventionally,
Such sealed packaged food is subjected to a heat sterilization treatment as a final stage after a predetermined food is sealed in a packaging container. Depending on the type of food, heating (heating aging treatment) for improving the flavor of the food is performed by this heating.

[0003] Heat sterilization in the final stage of this process has conventionally been
Although the method generally involves boiling treatment or steam application, it has a problem in that the treatment time is long and sterilization efficiency is poor. Therefore, with the aim of improving the efficiency of heat sterilization, the applicant has previously set up a high-frequency heating device configured so that the sealed packaged food is loaded in a flat annular container and this container is placed in contact between high-frequency counter electrodes. (Japanese Patent Application No. Hei 7-3)
29296).

According to such a high-frequency heating device, the inside of the container loaded with the sealed packaged food is sealed by the counter electrode abutting against the edge of the container, so that the sealed packaged food is sealed in the sealed container. It is possible to heat to 100 ° C. or more in the (food loading room), and thereby it is possible to perform a reliable sterilization treatment in a short time.

[0005]

Incidentally, the above-mentioned food loading chamber usually has an inner volume larger than the volume of the sealed packaged food, and the food loaded with the sealed packaged food sandwiched between the counter electrodes. Because there will be space in the room,
When dielectric heating is performed, the moisture in the sealed packaged food evaporates and the inside of the package becomes high pressure, which may damage the package. In order to avoid such inconvenience, in the high-frequency heating device, high-pressure air is introduced into the food loading chamber, thereby preventing the packaging container from expanding.

However, in order to introduce high-pressure air into the food loading chamber, air pressure means such as a compressor, high-pressure piping, and valves must be provided, which increases equipment costs and complicates the operation. In addition, there is a problem that energy is consumed for operation of the compressor and the like, and operation cost is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is necessary to keep the cost of equipment and operation low and to heat the sealed packaged food so that the packaging container is not damaged. It is an object of the present invention to provide a high-frequency heat sterilizer and a sterilization method capable of performing a sterilization process.

[0008]

According to the first aspect of the present invention,
A heat sterilization apparatus for heating and sterilizing a sealed packaged food by dielectric heating, comprising an upper electrode and a lower electrode, and a counter electrode to which a high frequency is applied, and an annular electrode interposed between the counter electrodes. A storage chamber for storing the sealed packaged food is formed with the insulator, and the storage chamber has an inner surface shape substantially matching the outer shape of the sealed packaged food.

According to the present invention, the sealed packaged food loaded in the sealed storage room is heated by the high frequency applied from the counter electrode, whereby the sealed packaged food is subjected to heat sterilization by dielectric heating. At the same time, the sealed packaged food is heat-aged. Then, even when the sealed packaged food tries to thermally expand due to the evaporation of moisture in the sealed packaged food at the time of dielectric heating of the sealed packaged food by high frequency, the entire peripheral surface of the sealed packaged food substantially adheres to the inner wall surface of the food loading chamber. As a result, the sealed packaged food does not undergo thermal expansion because it is blocked by the inner wall surface. Therefore, breakage of the sealed packaged food is prevented, and 10
Heat sterilization at 0 ° C. or higher is performed without interruption.

[0010] Even in the case where the hermetically sealed packaged food does not adhere well to the inner wall surface and a slight gap is formed between the two, the packaged container of the hermetically sealed packaged food can be removed only by the gap. By setting the strength so as to withstand the expansion, it is possible to sufficiently cope with the gap.

Further, even if the temperature of the sealed packaged food is raised to 100 ° C. or higher, the moisture contained in the food does not evaporate and remains in a liquid state, and the high pressure state is quickly propagated in the sealed packaged food and sealed. Since the pressure inside the packaged food is equalized, heat is also transferred during the process of equalization, whereby the temperature inside the sealed packaged food quickly becomes uniform and the dispersion of the sterilization treatment is eliminated.

According to the first aspect of the present invention, it is possible to heat-treat the sealed packaged food at the same time as the sterilization treatment, whereby the contents of the sealed packaged food can be stewed in curry dishes, stew dishes and the like. In the case of cooking, for example, the food is rich in flavor by performing a final stew aging treatment at the same time as the sterilization treatment. Also, when the sealed packaged food is boiled, such as Chikuzenni, which transfers the flavor of the broth to the material, the packaging container is made by simply adding the broth to the material that has just been distorted. In some cases, the final cooking is performed by heating through sterilization treatment, and the sealed packaged food becomes rich in flavor, that is, delicious.

According to a second aspect of the present invention, in the first aspect of the present invention, the upper electrode and the lower electrode are formed so that their opposing surfaces are respectively flat, and the insulator is provided on the outer peripheral surface of the hermetically sealed packaged food. It has an inner peripheral surface that substantially matches.

According to the present invention, the inner peripheral surface of the insulator is substantially in close contact with the outer peripheral surface of the sealed packaged food in a state where the sealed packaged food is stored in the storage chamber.

According to a third aspect of the present invention, in the first aspect of the present invention, one or both of the upper electrode and the lower electrode have a shape corresponding to the outer peripheral surface of the sealed packaged food. It is characterized by the following.

According to the present invention, the storage chamber can be adapted to sealed packaged food having various three-dimensional shapes other than the tray type.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a heating means for heating one or both of the counter electrode and the insulator is provided. It is characterized by the following.

According to the present invention, since the counter electrode and the insulator itself are heated by the heating means, the heating time of the sealed packaged food is shortened by the heat transfer from the counter electrode.

According to a fifth aspect of the present invention, in the first aspect of the present invention, there is provided a cooling means for cooling one or both of the counter electrode and the insulator. It is a feature.

According to the present invention, since the counter electrode itself is cooled by the cooling means, the cooling time of the sealed packaged food is shortened by transmitting cold heat from the counter electrode.

According to a sixth aspect of the present invention, there is provided a sealed packaged food comprising a counter electrode to which a high frequency is applied while sandwiching both sides thereof, and a sealing member sandwiched between the counter electrodes and sealing the sealed packaged food. A high-frequency heat sterilization method for loading the sealed packaged food in a storage chamber substantially matching the outer shape of the formed sealed packaged food and performing dielectric heating, and supplying a heating medium to the counter electrode in an auxiliary manner, A heating step of heating the sealed packaged food loaded in the storage chamber in a sealed state to a predetermined sterilization temperature by dielectric heating, and a sterilization step of maintaining the predetermined sterilization temperature raised in the temperature raising step for a predetermined time When,
The sterilization step comprises a cooling step of cooling the sealed packaged food subjected to the sterilization treatment.In the sterilization step, a heating medium is supplied to the counter electrode after stopping the dielectric heating, and the sterilization temperature is maintained. In the step, the supply of the cooling medium is supplied to the counter electrode after the supply of the heating medium to the counter electrode is stopped.

According to the present invention, the sealed packaged food is loaded into the storage chamber formed by the counter electrode and the sealing member, and the temperature rising step is performed. It is quickly heated and heated to a predetermined sterilization temperature in a short time. Next, in the sterilization step, the application of high frequency to the sealed packaged food is stopped, and the sterilization temperature is maintained for a predetermined time by the heating medium supplied to the counter electrode. Therefore, the sterilization temperature is maintained for a predetermined time in a state where the overheating by the dielectric heating is suppressed in the sterilization process, and the sterilization process without waste is realized.
Then, in the cooling step, direct heat exchange is performed between the sealed packaged food and the cooling medium by introducing the cooling medium to the counter electrode, and the sealed packaged food is rapidly forcibly cooled. After cooling, the sealed packaged food can be immediately taken out of the storage room.

[0023]

FIG. 1 is a partially cutaway perspective view showing a first embodiment of a high-frequency heating and sterilizing apparatus according to the present invention, and FIG. It is a notch perspective view. 3 is a cross-sectional view of the high-frequency heating and sterilizing apparatus shown in FIG. 1, wherein (a) shows a state where the container is opened, and (b) shows a state where the container is closed. As shown in these figures, the high-frequency heat sterilizer 1
Comprises a sterilizing container 2 for accommodating the sealed packaged food P, a high frequency generator 3 for applying a high frequency to the sealed packaged food P in the sterilized container 2, and a temperature adjusting unit 4 for adjusting the temperature of the sterilized container 2. Have been.

In the present embodiment, as the sealed packaged food P, a package is used in which a predetermined food is fully loaded in a rectangular tray-shaped packaging container P1 in plan view as shown in FIG. The tray-shaped packaging container P1 is provided with an annular edge P2 protruding outward at the upper edge, and after the food is loaded into the tray-shaped packaging container P1, the above-described annular edge P
2, a synthetic resin sheet P3 is stuck by heat fusion or the like,
As a result, a predetermined food is sealed in the tray-shaped packaging container P1.

The sterilization container 2 has a counter electrode 20 made of a metal plate having a rectangular shape in a plan view, that is, a lower electrode 21.
And an upper electrode 22 corresponding to the lower electrode 21 and an annular insulator 23 interposed between the opposed electrodes 20. An annular insulator 23 is provided on the upper electrode 22.
A heating chamber (storage chamber) 24 is formed.
The sealed packaged food P is stored in the heating chamber 24 and the counter electrode 2
0, and high-frequency heating is applied. A high frequency of several KHz to several hundred MHz is used, but in the present embodiment, a high frequency of 3 MHz to 300 MHz is used.

In the present embodiment, the annular insulator 23 is made of polytetrafluoroethylene which is excellent in heat resistance and is a very tough material.
An O-ring 241 made of synthetic rubber is provided at the center in the width direction of the front and back surfaces of the annular insulator 23, whereby the O-ring 241 is sandwiched between the counter electrodes 20 to provide a sealing effect in the heating chamber 24. Is ensured.

In the annular insulator 23, the three-dimensional shape of the heating chamber 24 formed in the center portion is the same as that of the tray-shaped packaging container P.
3 is set so as to conform to the three-dimensional shape of the tray packaging container P1 in the state where the sealed packaged food P is loaded in the annular insulator 23, as shown in FIG. 24, so that the thermal expansion of the tray-shaped packaging container P1 in the horizontal direction is prevented.

Then, as shown in FIG. 3A, after the sealed packaged food P is loaded in the annular insulator 23 on the lower electrode 21, as shown in FIG. The electrode 22 is lowered, and the synthetic resin sheet P <b> 3 of the sealed packaged food P comes into contact with the ceiling surface of the upper electrode 22 in a state where the upper electrode 22 is in contact with the annular insulator 23. As a result, the sealed packaged food P is sandwiched by the counter electrode 20 at a predetermined pressure (for example, 3 kg / cm ² ), so that thermal expansion in the vertical direction is prevented.

In the present embodiment, a pressing means 25 is provided on the upper surface of the upper electrode 22, and the sealing state in the heating chamber 24 is ensured by pressing the upper electrode 22 downward by the pressing means 25. I am trying to be.
More specifically, the pressing means 25 includes a hydraulic cylinder 26 suspended from a support frame (not shown) above the upper electrode 22.
And a piston rod 27 protruding downward from each of these hydraulic cylinders 26.

The piston rod 27 and the upper electrode 22
An insulating material 28 is interposed between the pressing means 25 and the upper electrode 22 so as to be electrically insulated from each other. In the present embodiment, the insulating material 28 is made of polyacetal resin or silicon resin.

The temperature control means 4 includes a steam generation source 41 composed of a boiler or the like, a cooling water supply source 42 such as a water supply,
The lower electrode 21 is formed to include a lower electrode temperature control pipe 43 disposed in a meandering state inside the lower electrode 21 and the upper electrode 22 provided with an upper electrode temperature control pipe 44 disposed in a meandering state.

The steam generation source 41 has a steam supply main line 41b for extracting the generated steam. The downstream end of the steam supply main pipe 41b is branched into two steam supply branch pipes 41b, and each of the steam supply branch pipes 41b is connected to the upstream end of the lower electrode temperature control pipe 43 and the upper electrode temperature control pipe 44. . The upstream end of a cooling water supply main pipe 42a is connected to the cooling water supply source 42, and the downstream end is branched into two cooling water supply branch pipes 42b. The downstream ends are connected to a lower electrode temperature control pipe 43 and an upper electrode temperature control pipe 44, respectively. Steam supply branch 41b
A synthetic resin flexible tube (not shown) is interposed at an appropriate position of the cooling water supply branch pipe 42b, so that the upstream side of the steam supply branch pipe 41b and the cooling water supply branch pipe 42b from the flexible tube is insulated from the counter electrode 20. Have been in a state.

The steam supply main pipe 41a is provided with a first control valve 45, and the cooling water supply main pipe 42a is provided with a second control valve 46. These control valves 45, 46 Opening and closing operation of each temperature control pipe 4
The steam from the steam generation source 41 and the cooling water from the cooling water supply source 42 are supplied to the sterilization container 2 and the heating chamber 2, respectively.
The temperature of the sealed packaged food P loaded in the container 4 is adjusted.

The downstream ends of the lower electrode temperature control pipe 43 and the upper electrode temperature control pipe 44 are open ends open to the outside, and the steam and cooling water supplied to these temperature control pipes 43 and 44 are supplied to the sterilization vessel 2. After being used for temperature control, the air is discharged outside the system through the open end.

The inner wall surfaces of the lower electrode temperature control pipe 43 and the upper electrode temperature control pipe 44 are insulated so that water and steam flowing through the electrode temperature control pipes 43 and 44 are electrically connected. To prevent any adverse effects.

FIG. 4 is a block diagram showing one embodiment of the high frequency generating means according to the present invention. As shown in this figure, the high-frequency generation means 3 includes a control circuit 31 for controlling the high-frequency heating and sterilizing apparatus 1 in general, an operation unit 32 for inputting various operation data to the control circuit 31, and a pair of opposed units. High frequency generator 33 for supplying high frequency power to electrode 20
It has.

The control circuit 31 controls the supply of power to the high frequency generator 33 based on the operation data input via the operation unit 32. The operation unit 32 is provided with operation buttons 320 including a start button 32a, a stop button 32b, and the like, and a data input key 321 for inputting the type and weight of the sealed packaged food P.

The start button 32a and the stop button 3
The operation signal from 2b is output to the control circuit 31 as a control signal via the control circuit 31. When the start button 32a is operated, the operation of the high frequency generator 33 is started, and when the stop button 32b is operated, the operation of the high frequency generator 33 is stopped.

The high frequency generator 33 includes a power supply circuit 34,
It is provided with a high frequency generating circuit 35 that generates high frequency by obtaining power from the power supply circuit 34, and a matching circuit 36 provided downstream of the high frequency generating circuit 35.
The power supply circuit 34 functions to convert, for example, a commercial power supply of 220 V into a DC power supply of a predetermined level. The high frequency generating circuit 35 is a self-excited oscillation type high frequency generating circuit that obtains a predetermined level of DC voltage from the power supply circuit 34 and generates a required level of high frequency energy. Further, the matching circuit 36 is a circuit for matching the high-frequency generation circuit 35 with a load (sealed packaged food P) passing between the pair of counter electrodes 20. In addition to the transformer 37, a matching capacitor (not shown) have.

The control circuit 31 can set an experimentally obtained power supply amount in accordance with the type, amount and thickness of the sealed packaged food P. This setting is performed by key-in using the data input key 321. When an input is made from the data input key 321, the output power from the power supply circuit 34 is set based on a previously stored arithmetic program. I have to.

FIG. 5 is an explanatory view showing an example of heat sterilization performed using the high-frequency heat sterilization apparatus of the first embodiment.
(A) is a process diagram, (b) is a sealed packaged food P is a sterilizing container 2
7 is a graph showing a change over time in the temperature of the sealed packaged food in each step executed in a state where the packaged food is loaded in the package. First, as shown in FIG. 5A, in the dielectric heat sterilization treatment, a loading step X of loading the sealed packaged food P into the heating chamber 24 of the sterilization container 2 is performed.
1. A sterilization step X2 for heat-sterilizing the sealed packaged food P loaded in the heating chamber 24, an extraction step X3 for extracting the sealed packaged food P that has been heat-sterilized in the sterilization step X2, and a sealed packaged food P after the removal. This is performed by a secondary cooling step X4 in which the water is cooled by being charged into a water storage tank (not shown).

In the sterilizing step X2, the sealed packaged food P is sterilized at a sterilizing temperature of 100 ° C. or more (for example, 110 ° C.).
To 140 ° C.), a sterilization temperature of the sealed packaged food P raised in the temperature increase step X21 for a predetermined time, a heat aging treatment, and a heating step X22 for sterilization, and a predetermined temperature. Primary cooling step X2 for cooling the heat-sterilized sealed packaged food P after maintaining the temperature for a period of time to approximately room temperature
3 are sequentially executed. Sealed packaged food P
Is cooled down to at least 100 ° C. in the primary cooling step X23 as shown in FIG.
Then, the sealed packaged food P is discharged into a cooling water tank (not shown), and is cooled to room temperature by the secondary cooling step X4 executed here. In the case where the sealed packaged food P is durable and the internal pressure slightly exceeds 1 atm (for example, even when the internal pressure becomes about 1.1 atm), the sealed packaged food P is not damaged,
As shown by the dotted line in FIG. 4B, the extraction step X3 may be executed at 100 ° C. or higher, and the process may be shifted to the secondary cooling step X4.

First, in the loading step X1, the sealed packaged food P is loaded into the heating chamber 24 of the lower electrode 21.
After that, the piston rod 27 is lowered by driving the hydraulic cylinder 26, and the upper electrode 22 is lowered by this, whereby the upper opening of the heating chamber 24 is closed.

When the upper opening of the heating chamber 24 is closed, as shown in FIGS. 1 and 3 (b), the upper electrode 22 is in a state where the ceiling surface presses the upper surface of the annular insulator 23. , Whereby a state is obtained in which the closed state of the heating chamber 24 is ensured. Moreover, in this state, the front and back surfaces of the sealed packaged food P loaded in the heating chamber 24 are in contact with the bottom surface of the lower electrode 21 and the ceiling surface of the upper electrode 22, and the side peripheral surface of the sealed packaged food P is the annular insulator 23. Is in close contact with the inner peripheral surface of the. Note that, also in the loading step X1, the first control valve 45 is kept in the open state, and heating of the sterilization container 2 by steam from the steam generation source 41 is continued.

Next, the sterilization step X2 is performed.
In the sterilization step X2, the supply of high frequency to the counter electrode 20 from the high frequency generation means 3 is started. As a result, the sealed packaged food P loaded in the heating chamber 24 is dielectrically heated by applying a high frequency to the sealed packaged food P from the counter electrode 20 to thereby perform a temperature raising step X21 in which the temperature is raised to a predetermined temperature. .

In the temperature raising step X21, the sealed packaged food P is rapidly heated by dielectric heating as shown in FIG.
Is exceeded, the moisture contained in the food in the inside evaporates, whereby the sealed packaged food P tends to thermally expand, but the sealed packaged food P adheres to the inner peripheral surface of the annular insulator 23 and the counter electrode 20. As a result, the expansion is prevented. As a result, the inside of the sealed packaged food P becomes high pressure and the boiling point of water rises, so that the moisture inside the sealed packaged food P remains in a liquid state without becoming steam. And
The temperature of the sealed packaged food P set in advance (for example, 110 to
When the temperature reaches 140 ° C.), the driving of the high frequency generator 3 is stopped, and the process proceeds to the heating step X22.

In the heating step X22, the above-mentioned temperature (for example, 110 to 140 ° C.) of the sealed packaged food P is maintained for a predetermined time only by the supply of steam from the steam generating source 41. Substantially heat sterilization of the food P is performed. When the heat sterilization in the heating step X22 for a predetermined time is completed, the next primary cooling step X23 is executed.

In the primary cooling step X23, first,
The control valve 45 is closed, whereby the steam source 4
The supply of steam from 1 to the sterilization container 2 is stopped. Next, the second control valve 46 is opened, and the cooling water from the cooling water supply source 42 is supplied to the lower electrode temperature control pipe 43 and the upper electrode temperature control pipe 44, thereby, as shown in FIG. Then, the sealed packaged food P in the heating chamber 24 is cooled down to 100 ° C. or lower. By this cooling process, it is possible to avoid maintaining a temperature suitable for the growth of bacteria for a long time, and to effectively prevent the reproduction of bacteria.

Next, when the sealed packaged food P is cooled to 100 ° C. or lower in the primary cooling step X23, the upper electrode 22 is raised by the lifting of the piston rod 27 by the driving of the hydraulic cylinder 26 in the next taking out step X3. The heating chamber 24 is opened. Next, the sealed packaged food P in the opened heating chamber 24 is taken out and the secondary cooling step X is performed.
4 and is introduced into a cooling water tank (not shown) and cooled to room temperature. By repeating each process by the batch processing using such a high-frequency heat sterilizer 1,
Heat sterilization is sequentially performed on the sealed packaged food P.

In the present invention, the sealed packaged food P is in close contact with the inner wall surface of the heating chamber 24 (ie, the inner peripheral surface of the annular insulator 23 and the contact surface of the counter electrode 20 with the sealed packaged food P). Because it is blocked by the inner wall and does not expand,
Therefore, in the sterilization step X2, the damage of the tray-shaped packaging container P1 due to the expansion of the sealed packaged food P is reliably prevented, and
The sterilization treatment of the sealed packaged food P at a temperature of 00 ° C. or more can be surely performed, and the food is heat-aged to increase the flavor of the food.

Further, even if the temperature of the sealed packaged food P is raised to 100 ° C. or more in the sterilization step X2, the moisture contained in the food does not evaporate and remains in a liquid state. Since the pressure is quickly propagated and the inside of the sealed packaged food P is equalized, heat transfer also occurs in the process of equalizing the pressure, whereby the temperature inside the sealed packaged food P quickly becomes uniform and the sterilization process varies. Is eliminated.

FIG. 6 is a schematic sectional view showing another embodiment of the high-frequency heating and sterilizing apparatus according to the present invention, wherein (a) shows the high-frequency heating and sterilizing apparatus 1a of the second embodiment, and (b) shows the third embodiment. Of the high-frequency heating and sterilizing apparatus 1b.

First, as shown in FIG. 6A, the high-frequency heating and sterilizing apparatus 1a of the second embodiment targets a tray-shaped packaging container P1 similarly to the first embodiment, and comprises a counter electrode. The lower electrode 21a and the upper electrode 22a of 20a are not flat on their respective opposing surfaces, but are provided with predetermined irregularities so as to match the three-dimensional shape of the sealed packaged food P in the heating chamber 24.

That is, the upper electrode 22a is provided with a swelling portion 221 swelling downward at the center of the lower surface, and the upper surface of the lower electrode 21a has a plane dimension smaller than that of the swelling portion 221. A large storage recess 211 is provided. The lower surface of the bulging portion 221 is set to a horizontal surface, while the storage recess 211 is set to match the shapes of the bottom surface and the outer peripheral surface of the sealed packaged food P.

The annular insulator 2 whose thickness is equal to the thickness of the bulging portion 221 is provided on the outer periphery of the bulging portion 221.
31 is externally fitted in sliding contact with the upper electrode 22.
The lower surface of “a” is flush. Therefore, when the upper electrode 22a is overlaid on the lower electrode 21a,
The upper chamber of the lower electrode 21a is in contact with the lower surface of the annular insulator 231 so that the lower electrode 21a and the upper electrode 22a are insulated from each other. 24 is formed. Other configurations are the same as those of the first embodiment.

According to the high-frequency heating and sterilizing apparatus 1a of the second embodiment, since the inner wall of the heating chamber 24 is integrated with the lower electrode 21a made of metal, the heating chamber 24 can withstand higher pressure. it can.

Next, as shown in FIG. 6 (b), the packaged food loading container 1b of the third embodiment is intended for a bag-shaped sealed packaged food P10, and includes an upper electrode 22a and an annular insulator. 231 is formed in the same manner as (a) in FIG. 6 of the second embodiment, but the lower electrode 21ba is formed into an elliptical shape in side view so that the storage recess 212 matches the outer shape of the bag-shaped hermetically sealed packaged food P10. Is formed. Other configurations are the same as those of the second embodiment.

According to the high-frequency heating and sterilizing apparatus 1b of the third embodiment, even if the bag-like hermetically sealed packaged food P10 is loaded into the heating chamber 24, the outer surface thereof reliably contacts the inner surface of the heating chamber 24, Thus, the bag-shaped sealed packaged food P10 is not damaged in the heat sterilization treatment.

In the high frequency heating and sterilizing apparatuses 1a and 1b of the second and third embodiments, the shape of the upper electrode and the shape of the lower electrode may be reversed.

FIG. 7 is a perspective view showing an embodiment of an automatic heat sterilization apparatus employed in the heat sterilization step, to which the fourth embodiment of the high-frequency heat sterilization apparatus according to the present invention is applied.
As shown in this figure, the automatic heating and sterilizing equipment 5 includes a high-frequency heating and sterilizing apparatus 1c, a container feeding mechanism 51 provided on the upstream side (left side in FIG. 7) of the high-frequency heating and sterilizing apparatus 1c,
A container discharge mechanism 54 provided on the downstream side of the high-frequency heating and sterilizing apparatus 1c.

In this embodiment, since the annular insulator 23 itself is used as a container for storing and moving the sealed packaged food P, the annular insulator 23 is hereinafter referred to as a transfer container 23a. The sealed packaged food P is sequentially loaded into the heating chamber 24 of the transfer container 23a, and is sequentially sent to the high-frequency heating sterilizer 1c via the container feeding mechanism 51,
Here, after being subjected to a predetermined heat sterilization treatment, it is sent to the next step via the container discharge mechanism 54.

In the present embodiment, the high-frequency heating and sterilizing apparatus 1c uses a counter electrode 20a which is larger than the counter electrode 20 of the previous embodiment, whereby three transfer containers 23a are formed on the lower electrode 21a at a time. In addition to being able to be placed in parallel, the upper electrodes 22a can close the upper openings of the three transfer containers 23a. The other configuration of the counter electrode 20a is the same as that of the first or second embodiment.

The container feeding mechanism 51 includes a belt conveyor 52 for feeding the transfer container 23a from the previous step to the heat sterilization step, and a belt conveyor 52 arranged in parallel with the belt conveyor 52 on the upstream side of the high-frequency heat sterilization apparatus 1c. Table 5 for pre-arranging three transfer containers 23a from
3 is provided.

The above-mentioned belt conveyor 52, array table 5
3 and the lower electrode 21a, the transfer container mounting surfaces are set at the same height level, whereby the transfer container 23a is moved from the mounting surface of the belt conveyor 52 to the mounting surface of the array table 53, and From the mounting surface of the lower electrode 2
1a can be slid to the mounting surface.

On the side of the belt conveyor 52 opposite to the arrangement table 53, a first push member 52a for pushing the three transfer containers 23a transferred by the belt conveyor 52 onto the arrangement table 53 is provided. A second push member 53a that pushes the three transfer containers 23a arranged on the arrangement table 53 onto the lower electrode 21a is provided. These push members 52a and 53a are reciprocated by the driving of a driving unit such as a hydraulic cylinder (not shown).

The container discharge mechanism 54 is provided with the counter electrode 20a.
5 provided adjacent to the lower electrode 21a on the downstream side of
5 and a roller conveyor 56 disposed on the upper surface of the base 55. The roller conveyor 56 is arranged such that a plurality of rollers are rotatable around an axis perpendicular to the transport direction of the transfer container 23a, and the transfer container 23a from the high-frequency heating and sterilizing apparatus 1c is driven by the rotation of each roller conveyor 56. It is configured to discharge to the next step.

The belt conveyor 52 is operated by an intermittent drive in which it travels a distance corresponding to three transfer containers 23a and then temporarily stops.
The first push member 52a reciprocates at the time of stoppage of the second and the three transfer containers 23a are transferred onto the array table 53.

The transfer container 23a transferred to the arrangement table 53 is transferred to the lower electrode 21a by a push operation of the second push member 53a in the transport direction. The three transfer containers 23a transferred onto the lower electrode 21a are pressed and held between the upper electrode 22a and the lower electrode 21a by the lowering of the upper electrode 22a.
The heat sterilization treatment described above with reference to FIG. 5 is performed on the inside sealed packaged food P.

Then, after the heat sterilization treatment by the high-frequency heat sterilizer 1c is completed, the upper electrode 22a is raised,
The three transfer containers 23a on the lower electrode 21a are pushed out onto the roller conveyor 56 by the pushing operation of the second push member 53a. The transfer container 23a pushed out onto the roller conveyor 56 is sent out to the next step by the rotation of the roller conveyor 56.

As described above, the belt conveyor 52 and the first
By the intermittent driving of the push member 52a, the second push member 53a, and the upper electrode 22a, the sealed packaged food P in the transfer container 23a sequentially fed by the belt conveyor 52 is sequentially heated in the high-frequency heating and sterilizing apparatus 1c. It is sterilized and discharged sequentially by the container discharging mechanism 54.

According to the automatic heating and sterilizing equipment 5, a large amount of sealed packaged foods P can be heated and sterilized without human intervention, and the effect of reducing operating costs is great.

FIG. 8 is a schematic sectional view showing a fifth embodiment of the high-frequency heating / sterilizing apparatus 1d according to the present invention. In this embodiment, the same sealing member 23 as that of the first embodiment is employed, but the counter electrode 20b (the lower electrode 21) is used.
b and the upper electrode 22b) have a concave portion 21c formed at the center of each opposing surface, and the upper and lower portions of a sealed packaged food P such as a cup food are fitted into the concave portion 21c. Other configurations are the same as those of the first embodiment.

FIGS. 9 and 10 are perspective views showing a sixth embodiment of the high-frequency heating and sterilizing apparatus 1e according to the present invention.
FIG. 9 shows a state in which the upper electrode is open, and FIG. 10 shows a state in which the upper electrode is closed. 9 and 10, the XX direction is referred to as the width direction, the YY direction is referred to as the front-rear direction, the −X direction is referred to the left, the + X direction is referred to the right, and the −Y direction is the front. , + Y direction is called backward.

In the sixth embodiment, the sterilization container 2a
Is different from the previous embodiment in that it is movable including the counter electrode 20c. The upper electrode 220 is openable and closable, and the lower electrode 21
0 is fixed to the bottom of the sealing member 23. Locking means 2 for locking the closed state of the upper electrode 220 is provided.
50 are provided.

On the other hand, the lower electrode 210 has a pair of L-shaped lower hinges 213 projecting from the left side in the front-rear direction, and the upper electrode 220 has an L-shape facing the lower hinge 213. The upper electrode 220 is rotatable around the bolt, and the upper electrode 220 is rotatable around the bolt. 210. In addition, each said hinge 213,
223 is formed of a tough engineering plastic which is a non-conductive material, thereby forming the lower electrode 21.
0 and the upper electrode 220 are insulated.

The locking means 250 is provided on the right side of the lower electrode 210 in the width direction. The locking means 250 includes a bracket 251 projecting outward from a center portion of the lower electrode 210 on the right side in the width direction, a bracket 251, and a first horizontal shaft 252.
A bifurcated rotating piece 253 rotatably pivoted around,
The tip of the rotating piece 253 is held between the second horizontal shaft 2
Bifurcated lock piece 25 rotatably supported around 54
6 is provided.

An operation piece 255 projecting outward from the bifurcation of the lock piece 256 is provided at the right end in the width direction of the rotation piece 253.
Is operated to rotate the rotating piece 253 forward and backward around the first horizontal axis 252, so that the lock piece 256 moves up and down.

A locking claw 39a projecting counterclockwise around the second horizontal shaft 254 is provided at the tip of the lock piece 256.
On the other hand, a plate-shaped insulator 47 is provided at the upper edge of the right end of the upper electrode 220 in the width direction at a portion corresponding to the locking claw 39a. A locking projection 47a with which the pawl is engaged is provided in a protruding manner. Then, with the upper electrode 220 closed, the locking claw 39a is locked to the locking projection 47a, and the operation piece 255 is moved to the first horizontal shaft 2
By rotating clockwise around 52, the insulator 4
7, while the insulating state between the lower electrode 210 and the upper electrode 220 is maintained by the lock piece 2 as shown in FIG.
The base end side of 56 is lowered to be in a locked state in which the second horizontal shaft 254 is located slightly to the left in the width direction from the first horizontal shaft 252, whereby the pressure in the food loading chamber 21a becomes higher than 1 atm. Also, a closed space from which high-pressure fluid does not leak is formed.

Conversely, when the operation piece 255 is rotated counterclockwise around the first horizontal axis 252 in the locked state of the upper cover closed state shown in FIG. 10, the lock piece 256 rises and the locking claw 257 is locked. The engagement with the protruding piece 222 is released, whereby the locked state of the closed upper electrode 220 is released.

In the unlocked state, as shown in FIG. 9, the rotating piece 253 is kept in a horizontal position by the urging force of the urging means (not shown), and the lock piece 256 is The vertical posture is maintained by the urging force of the substantially urging means, whereby the posture of the lock means 250 in the unlocked state is stabilized, and the lock operation is easily automated. .

In this embodiment, the locking means 250
Has a pressure resistance enough to withstand the pressure in the sealed packaged food P loaded in the heating chamber 24 even when the pressure becomes approximately 3 kg / cm ^2. Of the sealed packaged food P can be suppressed even when the temperature of the container becomes 110 ° C. to 140 ° C.

The lower electrode 210 and the upper electrode 22
0 is provided with a fluid introduction base 451 detachably connected to the steam supply branch pipe 41b and the cooling water supply branch pipe 42b (FIG. 1), and a fluid discharge base 452 is provided. By connecting the base 451 to one of the supply branch pipes 41b, 42b, steam or cooling water is introduced into the electrodes 210, 220,
The fluid is discharged to the outside through a fluid discharge port 452. Each of these bases 451 is provided with an open / close valve.
Steam can be circulated or cut off inside the 10, 220.

As a conveyor belt for transferring the sterilizing container 2a, a pair of widthwise timing belts 11 having meshing teeth formed on the back surface is employed. And
By the orbital movement of the timing belt 11 driven by the drive mechanism (not shown), the sterilization container 2a moves to the high-frequency application position, and the high-frequency connection terminal is brought into contact with the lower electrode 210 and the upper electrode 220. It functions as the counter electrode 20c.

According to the sterilization container 2a of the second embodiment, the upper electrode 220 is closed and locked by the lock means 250 in a state where the sealed packaged food P is loaded in the heating chamber 24, so that the inside of the heating chamber 24 is Since the sealed packaged food P in the heating chamber 24 is heated to a high temperature by the dielectric heating due to the sealed state, the upper electrode 220 is not opened even if the pressure in the heating chamber 24 becomes a high pressure. There is no need to press and hold the lower electrode 210 and the upper electrode 220 with the electrodes, and the dielectric heating unit can be simplified.

The present invention is not limited to the above embodiment, but includes the following contents.

(1) In the first and second embodiments described above, the plane dimensions of the counter electrode 20 are set to be substantially the same as the plane dimensions of the annular insulator 23, and in the fourth embodiment, the plane dimensions of the counter electrode 20a are set. The plane dimensions are set to the size of three annular insulators 23 (transfer containers 23a).
The present invention is not limited to setting the size of the counter electrode 20 to be substantially the same as or three times as large as the size of the annular insulator 23, but is not limited to two or four or more annular insulators 23. Size.

(2) In the above embodiment, the lower electrode 21 has the lower electrode temperature control pipe 43 and the upper electrode 2
Although the upper electrode temperature control pipe 44 is buried in 2, the present invention is not limited to burying the electrode temperature control pipes 43 and 44 in the counter electrode 20, It is also possible to form a through hole that penetrates in the horizontal direction, and connect a pipe to the through hole.

(3) In the above embodiment, the steam and the cooling water from the steam generating source 41 and the cooling water supply source 42 are switched and supplied at a predetermined timing into the opposed electrodes 20 and 20a. In the present invention, the supply of steam and cooling water into the opposed electrodes 20 and 20a is not essential, and either one of them may be supplied, or both may not be supplied.

(4) In the above embodiment, the sealed packaged food P is used in a tray shape, but the present invention is limited to the sealed packaged food P having a tray shape. Instead of a thing, it may be a bag-like thing, and what showed other three-dimensional shapes may be used. However,
It is necessary to make the inner peripheral surface of the annular insulator 23 conform to the three-dimensional shape of the sealed packaged food.

(5) In the above embodiment, the sterilizing container 2 is constituted by the counter electrode 20 and the annular insulator 23. The sterilization container is not limited to the structure of 23, but is configured to be capable of being sealed with a non-conductive material, and this sterilization container is sandwiched between the counter electrodes 20 to dielectrically heat the sealed food package P inside. You may do so. Further, the sterilizing container comprises an annular member made of a non-conductive material, and an upper lid and a bottom lid made of a conductive material for closing the upper opening and the lower opening of the annular member. P may be loaded and sandwiched between the opposing electrodes 20, thereby performing dielectric heating.

(6) In the above embodiment, heat medium such as steam from the steam generation source 41 and cooling water from the cooling water supply source 42 is supplied to both the upper electrodes 22 and 22a and the lower electrodes 21 and 21a and 21b. However, the present invention is not limited to the case where steam is introduced into both the upper electrodes 22 and 22a and the lower electrodes 21 and 21a and 21b. Alternatively, a flow path for the heat medium may be formed inside the sealing member 23 in addition to the above, and the heat medium may be supplied to the flow path.

(7) In the above embodiment, the secondary cooling step X4 for cooling the sealed packaged food P to normal temperature is provided after the take-out step X3, but the present invention provides a secondary cooling step X4. Is not limited to providing
In the primary cooling step X23, cooling to room temperature may be performed, or after the primary cooling step X23, natural cooling may be performed to cool to room temperature. In the case where only the primary cooling step is continued, the temperature drop straight line indicates the temperature drop gradient in the primary cooling step X23 as indicated by the two-dot chain line even in the portion described as the secondary cooling step X4 in FIG. Will be continued.

[0093]

According to the first aspect of the present invention, a counter electrode comprising an upper electrode and a lower electrode, to which a high frequency is applied, and an annular insulator interposed between the counter electrodes. A storage room for storing the sealed packaged food is formed, and the storage room is formed into a three-dimensional shape that matches the outer shape of the sealed packaged food, so that the sealed packaged food loaded in the sealed storage room is
The packaged food is heated by the high frequency applied from the counter electrode, whereby the packaged food can be subjected to heat sterilization treatment by dielectric heating, and the packaged food can be thermally aged. And, at the time of dielectric heating of the sealed packaged food by high frequency, even if the sealed packaged food tries to thermally expand due to evaporation of moisture in the sealed packaged food, the sealed packaged food is
Since the entire peripheral surface is in close contact with the inner wall surface of the food loading chamber, it is blocked by the inner peripheral wall, and thermal expansion of the sealed packaged food can be prevented. Accordingly, breakage of the sealed packaged food can be reliably and reliably prevented, and heat sterilization at 100 ° C. or more can be performed without delay.

Further, even if the temperature of the sealed packaged food is raised to 100 ° C. or higher, the moisture contained in the food does not evaporate and remains in a liquid state, and the high pressure state is quickly propagated in the sealed packaged food and sealed. Since the pressure inside the packaged food is equalized, heat transfer also occurs during the process of equalization, and this allows the temperature inside the sealed packaged food to be quickly brought to a uniform temperature, thereby eliminating variations in the sterilization treatment. It is valid.

According to the second aspect of the present invention, each of the opposing surfaces of the upper electrode and the lower electrode is formed to be flat, and the insulator has an inner peripheral surface substantially coinciding with the outer peripheral surface of the sealed packaged food. Therefore, in a state where the sealed packaged food is stored in the storage room, the inner peripheral surface of the insulator becomes substantially in close contact with the outer peripheral surface of the sealed packaged food, and particularly, the tray type sealed packaged food is suitably loaded in the storage room. be able to.

According to the third aspect of the present invention, the lower electrode is formed in a shape such that the upper surface thereof coincides with the side surface and the bottom surface of the sealed packaged food. Can be made to correspond.

According to the fourth aspect of the present invention, since the heating means for heating the counter electrode is provided, the counter electrode itself can be heated by the heating means. Can be shortened.

According to the fifth aspect of the present invention, since the cooling means for heating the counter electrode is provided, the counter electrode itself can be cooled by the cooling means, and the cooling time of the sealed packaged food by the heat transfer from the counter electrode. Can be shortened.

According to the sixth aspect of the present invention, there is provided a hermetically sealed packaged food, wherein the hermetically sealed packaged food loaded in the storage chamber in a sealed state is heated to a predetermined sterilization temperature by dielectric heating;
A sterilization process is performed through a sterilization process of maintaining a predetermined sterilization temperature raised in the temperature raising process for a predetermined period of time and a cooling process of cooling the sealed packaged food that has been subjected to the sterilization process in the sterilization process. In the process, the heating medium is supplied to the counter electrode after stopping the dielectric heating to maintain the sterilization temperature, and in the cooling step, the cooling medium is supplied to the counter electrode after stopping the supply of the heating medium to the counter electrode. Therefore, by loading the sealed packaged food into the storage chamber formed by the counter electrode and the sealing member and performing the temperature raising step, the sealed packaged food is rapidly heated by applying a high frequency from the counter electrode. It can be heated up to a predetermined sterilization temperature in a short time. Next, in the sterilization step, the application of high frequency to the sealed packaged food is stopped, and the sterilization temperature can be maintained for a predetermined time by the heating medium supplied to the counter electrode. Therefore, overheating due to dielectric heating is suppressed in the sterilization process, so that an appropriate sterilization temperature can be maintained for a predetermined time, and a sterilization process without waste can be realized. Then, in the cooling step, direct heat exchange is performed between the sealed packaged food and the cooling medium by introducing the cooling medium to the counter electrode, and the sealed packaged food is rapidly forcibly cooled. After cooling, the sealed packaged food can be immediately taken out of the storage room.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a first embodiment of a high-frequency heating and sterilizing apparatus according to the present invention.

FIG. 2 is a partially cutaway perspective view showing one embodiment of an annular insulator.

3 is a cross-sectional view of the high-frequency heating and sterilizing apparatus shown in FIG. 1, wherein (a) shows a state where the container is opened, and (b) shows a state where the container is closed.

FIG. 4 is a block diagram showing one embodiment of a high-frequency generator according to the present invention.

FIG. 5 is an explanatory view showing an example of heat sterilization performed using the high-frequency heat sterilization apparatus according to the first embodiment, in which (a) is a process diagram, and (b) is a state in which sealed packaged food is loaded in a sterilization container. 6 is a graph showing a change over time in the temperature of the sealed packaged food in each step performed in the step (a).

FIG. 6 is a schematic cross-sectional view showing another embodiment of the high-frequency heat sterilizer according to the present invention, wherein (a) is the high-frequency heat sterilizer of the second embodiment, and (b) is the high-frequency heat sterilizer of the third embodiment. Each device is shown.

FIG. 7 is a perspective view showing an embodiment of an automatic heat sterilization equipment employed in a heat sterilization step, to which a fourth embodiment of the high-frequency heat sterilization apparatus according to the present invention is applied.

FIG. 8 is a schematic sectional view showing a fifth embodiment of the high-frequency heating and sterilizing apparatus according to the present invention.

FIG. 9 is a perspective view showing a sixth embodiment of the high-frequency heating and sterilizing apparatus according to the present invention, showing a state in which an upper electrode is opened.

FIG. 10 is a perspective view showing a sixth embodiment of the high-frequency heating and sterilizing apparatus according to the present invention, showing a state in which an upper electrode is closed.

[Explanation of symbols]

 1, 1a, 1b, 1c, 1d High-frequency heating sterilizer 2, 2a Sterilization container 20, 20a, 20b, 20c Counter electrode 21, 21a, 21b Lower electrode 211, 212 Storage recess 22, 22a Upper electrode 23 Ring insulator 23a Transfer Container (annular insulator) 24 Heating chamber (storage chamber) 25 Pressing means 26 Hydraulic cylinder 27 Piston rod 250 Locking means 251 Bracket 252 First horizontal axis 253 Rotating piece 254 Second horizontal axis 255 Operation piece 256 Lock piece 257 Lock Claw 3 High frequency generating means 4 Temperature adjusting means 41 Steam generating source 42 Cooling water supply source 5 Automatic heating and sterilizing equipment 51 Container feeding mechanism 52 Belt conveyor 53 Array table 54 Container discharging mechanism 55 Base 56 Roller conveyor P, Pa Sealed packaged food

Claims (6)

[Claims] 1. A heat sterilization apparatus for sterilizing a sealed packaged food by heating it by dielectric heating, comprising an upper electrode and a lower electrode, and a high-frequency applied counter electrode, and an intervening electrode between the counter electrode. A storage chamber for storing the sealed packaged food is formed with the annular insulator provided, and the storage chamber has an inner surface shape substantially matching the outer shape of the sealed packaged food. Sterilizer. 2. The upper electrode and the lower electrode are formed so that their opposing surfaces are respectively flat, and the insulator has an inner peripheral surface substantially coinciding with the outer peripheral surface of the sealed packaged food. The high frequency heating and sterilizing apparatus according to claim 1, wherein 3. The high-frequency heat sterilizer according to claim 1, wherein one or both of the upper electrode and the lower electrode have a shape corresponding to the outer peripheral surface of the sealed packaged food. 4. The high-frequency heating and sterilizing apparatus according to claim 1, further comprising heating means for heating one or both of the counter electrode and the insulator. 5. The high-frequency heating and sterilizing apparatus according to claim 1, further comprising cooling means for cooling one or both of the counter electrode and the insulator. 6. A counter electrode to which high frequency is applied while sandwiching both sides of the sealed packaged food, and sandwiched between the counter electrodes,
In addition, the sealed packaged food is loaded into a storage chamber substantially conforming to the outer shape of the sealed packaged food formed from the sealing member that seals the sealed packaged food, and is dielectrically heated, and the counter electrode is supplementarily heated with heat. A high-frequency heating sterilization method for supplying a medium, wherein the temperature of the sealed packaged food loaded in a sealed state in the storage chamber is raised to a predetermined sterilization temperature by dielectric heating, and the temperature is raised in the temperature raising step. A sterilization step of maintaining the predetermined sterilization temperature for a predetermined period of time, and a cooling step of cooling the sealed packaged food that has been subjected to sterilization in the sterilization step, in the sterilization step after stopping the dielectric heating, the counter electrode A high-frequency heating and sterilizing method, wherein a heating medium is supplied to maintain a sterilizing temperature, and in the cooling step, a cooling medium is supplied to the counter electrode after the supply of the heating medium to the counter electrode is stopped. .