JP2658139B2 - Microwave heating sterilizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application field> The present invention relates to a sterilizer for continuously irradiating microwaves on a package in which an object to be sterilized is sealed, and sterilizing the package, particularly for business use. The present invention relates to a microwave heating and sterilizing apparatus in which a large-sized package containing a large amount of materials to be sterilized is heated to reduce variations in the temperature of each part.

<Conventional Apparatus> Many methods have been already reported for continuously heating and sterilizing a package filled with bags or containers containing an object to be sterilized by microwaves. The heating temperature during sterilization tends to be high at the periphery and low at the center. In particular, the tendency is high for solids that do not produce convection or for high-viscosity products to be sterilized. Therefore, in actual sterilization, it was necessary to control the temperature at the central heating temperature where the temperature was low. As a result, the peripheral portion where the temperature becomes high is excessively heated, which has an adverse effect on quality.

On the other hand, when the above-mentioned package is stored in a support made of a material which can transmit microwaves and heated, the peripheral end of the package has a small heat capacity, heat transfer from a portion in contact with the support, and heat dissipation from a gap. As a result, the temperature was lower than that in the center. In particular, the tendency was remarkable near the seal portion of the package.

On the other hand, a method of intermittently irradiating microwaves and making the temperature of the package uniform by heat conduction during non-irradiation is also conceivable.However, in the case of germ-free materials without convection, it is necessary to eliminate the temperature difference of 10 ° C. At least three minutes are required, and short-time heating, which is a feature of microwave heating, becomes impossible.

Furthermore, in a large package containing a large amount of sterilized materials, even in the case of a sterilized material such as a convective liquid, it is difficult to uniformly heat the central portion and the peripheral portion of the package with large temperature variations. .

<Problems to be Solved by the Invention> The present invention makes use of the characteristics of short-time heating by microwaves, and in particular, can minimize the final temperature variation of a large package containing a large amount of materials to be sterilized. It is an object to provide a microwave heating sterilizer.

<Means for Solving the Problems> The present invention provides a container for an object to be sterilized which can be heated by microwaves,
Alternatively, a conveying device for transferring the support, a transfer device for transferring the support, and a device for storing the package stored in the bag in a support made of a material capable of transmitting microwaves, irradiating the microwave while heating and sterilizing by heating. A first heating chamber including a plurality of cavities having waveguides arranged at different positions in a direction perpendicular to the transfer direction, with the irradiation port approaching below the transfer body along the direction, and heating the entire package. This is a microwave heating and sterilizing apparatus provided with a second heating chamber provided with a waveguide having an irradiation port on the wall surface to be irradiated.

Further, the present invention is a microwave heating and sterilizing apparatus provided with a reversing mechanism for reversing a support housing a package in a second heating chamber.

Further, in the present invention, when the object to be sterilized does not generate convection due to heating, the position of the irradiation port of the waveguide arranged in the cavity of the first heating chamber is arranged not only below the package but also above the package. It is a microwave sterilizer.

<Effect> In the first heating chamber, the irradiation port of the waveguide extends to near the lower part of the package, and irradiates sequentially different portions in the direction perpendicular to the transport direction of the package, so that the irradiated microwave is emitted. Is irradiated without diffusing to the irradiation part of the package,
Not only the central part but also the peripheral end of the package is partially heated, so that the temperature difference between the central part and the peripheral part can be reduced.

Further, when the material to be sterilized is a solid material or a high-viscosity material, by arranging a waveguide close to the irradiation port not only at the bottom but also at the top, as described above, the peripheral portion and the central portion of the package body. And the temperature difference can be reduced.

In the second heating unit, the package is reversed by the reversing mechanism, so that the temperature difference between the front and back of the package can be reduced.

<Example> Fig. 1 is an explanatory view showing an example of a microwave sterilizer according to the present invention. , 20A and waveguides 10B, 11B extending from the microwave oscillator
A cavity is provided in which 12B, 13B, 14B, 15B, and 20B are arranged.

Of these, waveguides 10B, 11B, 12B, 13B, 14B, 15B are:
Extends to below the support A, each irradiation port is close,
A first heating chamber for partially heating the package is formed.

The irradiation port of the waveguide 20B is provided in a cavity, and forms a second heating chamber for heating the entire package.

Then, the support A containing the package is supplied to the conveyor 8 and is conveyed to the first heating unit through the microwave trap 5, where the material to be sterilized in the package is partially heated. The whole package is heated by the second heating unit, and the sterilized package is taken out again through the microwave trap 7.

Here, the waveguides 10B, 11B, 12B, 1 in the first heating unit are used.
3B, 14B, the distance between the irradiation port of the cyclowave of 15B and the package may be performed by moving the waveguide in the range of 10 to 15 mm,
Further, the size of the irradiation port of the waveguide is adjusted by changing the size of the slit attached to the irradiation port.

Then, as shown in FIG. 2, the waveguide 10B of the first heating section is formed.
Nos. 15B to 15B have a structure in which irradiation ports are arranged at different positions with respect to the transport direction, and the irradiation position of the package can be sequentially changed.

When the first heating unit is partially heated, it is effective to intermittently move the package B and stop the support A so as to be above the irradiation port of the waveguide.

For example, as shown in FIG. 3, the bag-shaped package B is heated at the position shown in FIG.
_{a 1, a 2, a 3} , a 4, a 5, and irradiated with microwaves to a _6, heated in the second heating portion of the next irradiating the whole including the peripheral portion is heated.

When the material to be sterilized is a solid material such as a hamburger or a highly viscous material, as shown in FIG. 4, the position of the waveguide of the first heating unit is positioned not only below but also above. , From above and below.

In the sterilizing apparatus shown in FIGS. 1 and 4, it is more effective to provide the second heating unit with a reversing mechanism for reversing the support as the support moves as shown in FIG. .

That is, the support shafts 30A and 30B are provided at point-symmetric positions from the centers on both sides of the support A, and while the support A is being transferred to the support shaft by the attached lent, the sliding is higher than the other portions during the transfer of the support A. By performing the reversing by the reversing mechanism 34 provided with the surface 32 and the reversing groove 33, more uniform heating is possible.

<Effect> According to the apparatus of the present invention, the temperature difference between the respective parts during heating and heating of the package by microwave is small, and the temperature difference is small even at the end of heating. Heating can be performed almost uniformly, and in particular, even in a large package that could not be performed by the conventional microwave heating method, uniform heating by micro-heating can be performed.

This makes it possible to reduce the temperature variation in a large package in continuous microwave heat sterilization, prevent quality deterioration due to excessive heating, and enable uniform heating in a short time.

In addition, by disposing the waveguide not only below but also above, it is possible to heat the solid or high-viscosity material that does not generate convection due to heating, with a small variation in temperature.

Further, by providing a reversing mechanism in the second heating unit,
Not only the temperature on the same surface but also the temperature difference between the front and back of the package can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of the microwave heating sterilizer of the present invention, FIG. 2 is an explanatory view showing the position of the waveguide of the first heating unit in FIG. 1, and FIG. FIG. 4 is an explanatory view showing another example of the microwave heating device, and FIG. 5 is an explanatory view showing a reversing mechanism of a second heating unit. A: Support, B: Package 10A, 11A, 12A, 13A, 14A, 15A, 20A ... Microwave oscillator 10B, 11B, 12B, 13B, 14B, 15B, 20B ... Waveguide

Claims (4)

(57) [Claims] An object to be sterilized, which can be heated by microwaves, is a container,
Alternatively, a conveying device for transferring the support, a transfer device for transferring the support, and a device for storing the package stored in the bag in a support made of a material capable of transmitting microwaves, irradiating the microwave while heating and sterilizing by heating. A first heating unit composed of a plurality of cavities in which the irradiation ports are arranged below the package along the direction and waveguides arranged at different positions in the direction perpendicular to the transfer direction and the entire package are heated. A microwave heating and sterilizing apparatus provided with a second heating unit provided with a waveguide having an irradiation port on a wall surface to be irradiated. 2. The microwave sterilizer according to claim 1, wherein the irradiation port of the waveguide disposed in the cavity of the first heating section is disposed at a position close to above and below the package. 3. The microwave heating sterilizer according to claim 1, wherein a reversing mechanism is provided in the second heating section. 4. The microwave heating sterilizer according to claim 2, wherein the second heating section is provided with a reversing mechanism.