JPS63317068A - Method for high-frequency heating-sterilizing - Google Patents

Abstract

PURPOSE:To enable uniform heating and efficient sterilization of a substance, by irradiating the substance with high frequency in the form of circularly polarized waves. CONSTITUTION:A substance is irradiated with high frequency in the form of circularly polarized waves. As a means for converting the high frequency into the circularly polarized waves, methods for using a helical conductor (A), using two 1/4-wavelength plate (B) or using an antenna (D) having a T-shaped slot placed in a spiral form, etc., are cited. High frequency generated from the output antenna part is converted into the circularly polarized waves in a stage of irradiating the substance therewith in a high-frequency heating.sterilization method and uniform irradiation can be carried out even without using a means for rotating the substance irradiated therewith, etc. Since the circularly polarized waves are used for heating the substance, uniform heating can be carried out without heating the substance in an overheated state as in a conventional method. As a result, if the substance is a food, a state of hardly any deterioration in taste and color can be kept.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of heating or sterilizing foods, etc. using high frequency waves. <Prior art> Foods, bacteria, and other substances to be heated 8 or sterilized are
It is composed of molecules, and generally has a positive potential paired with a negative electron bound nearby.

Microscopically, it is a collection of positive and negative dipoles, but the electric field as a whole is close to zero.

Heating devices such as conventional microwave ovens that heat substances such as foods use TEM waves (transve-rse) emitted from the output antenna of a magnetron.
Electromagnetic Waves) were irradiated onto the article as linearly polarized waves using a waveguide and a reflector.

For this reason, only the dipoles of the molecules in the material that are parallel to the linearly polarized electric field absorb the energy of the external electric field, resulting in non-uniform heat generation in which only the part of the molecules in a specific direction in the material generates heat. Met.

On the other hand, most of the molecular dipoles located at positions orthogonal to the linearly polarized electric field did not respond to the incident microwaves at all, and uniform heating and sterilization effects could not be obtained.

Furthermore, the dipoles of molecules parallel to the linearly polarized waves become overheated, causing problems such as deterioration of taste in the case of foods and deformation and rupture of the packaging in the case of packaged foods.

Furthermore, in order to uniformly heat the heating device by using linearly polarized waves, the linearly polarized waves are diffusely reflected by a stirrer l as shown in FIG.

Rotation, vibration, etc. of the article by the table 2 were necessary.

As shown in Fig. 6, even in the microwave continuous heating device that continuously moves the substance to the belt controller 73 and irradiates it with microwaves, linearly polarized waves are used by rectangular waveguides. By the time the microwave reaches the material from the magnetron.

The actual situation was that ignition occurred at the flange, some corners, etc., resulting in poor energy efficiency and insufficient heating and sterilization effects compared to the IT type. .

Problems to be solved> As described above, all conventional microwave heating devices use linearly polarized waves as microwaves.

Not only was it not possible to use energy effectively, but substances such as foods were also heated excessively, leading to accidents such as deterioration of taste and rupture of packaging.

Therefore, it is an object of the present invention to provide a high-frequency heating/sterilization method that enables uniform heating and efficient sterilization by using circularly polarized waves instead of linearly polarized waves.

Means to solve the problem〉 The problem was solved by using circularly polarized waves as the high-frequency waves to irradiate the material.

Means for making high frequency waves into circularly polarized waves include a method using a spiral conductor A as shown in Fig. 1, a method using two quarter-wave plates B as shown in Fig. 2, or As shown in FIG. 3, there is a method using an antenna D in which T-shaped slots are arranged in a spiral manner.

Effect> Heating and sterilization using circularly polarized high frequency waves is performed according to the principle shown in the following formula.

H= H*eosPcosWt + HosinPsi
nWt Here, H is electrical displacement, Ho is amplitude, P is phase difference of electrical displacement with respect to electric field, and W is angular velocity, and represents time.

When circularly polarized high frequency waves are used, the heating and sterilization efficiency reaches its maximum value when P=90 degrees.

〔Example〕

An example of the apparatus used in the method of the present invention will be explained with reference to the drawings.

FIG. 4 is an explanatory view showing one embodiment of the apparatus using the present invention, in which a magnetron 11° output antenna section 12 is installed on the top of the oven 10, and a slot 1 is placed below the output antenna section 12.
Antenna D with 3, material storage part 15, dielectric plate 1
6. And the reflection jJ117 consisting of a concave mirror at the bottom
This is a high-frequency heating and sterilization device equipped with

This antenna is 1, for example as shown in FIG.

It consists of an antenna D in which T-shaped slots are arranged in a spiral shape.

Although the two reflecting mirrors 17 are not necessarily necessary, they are preferable because they allow effective use of high frequencies.
6 and the reflecting mirror 17 is preferably set to the abbreviation of the wavelength of the high frequency wave oscillated from the output antenna section 12, and from the point of view of efficiency, the height of the material storage section 15 is set to the abbreviation of the wavelength. It has been sharpened since then.

In addition, in the device shown in FIG. 4, the output antenna section 12 is located at the upper part, and the reflecting mirror 17 is located at the lower part. Although I do.

In addition, the output antenna part 12 and the lower part 1 reflecting mirror 17 may be located at the upper part.

Instead of arranging the output antenna part and reflector vertically,
Alternatively, it may be provided on either the front or both sides.

In any of the above cases, the antenna and substance storage section.

The dielectric plates are provided in this order in the same positional relationship as in FIG.

As for the antenna, not only the antenna shown in FIG. 3 but also the antenna shown in FIG. 1 or 2 can be used to obtain the same effect.

Effects> In the method of the present invention, the high frequency wave oscillated from the output antenna section becomes a circularly polarized wave at the stage of irradiating the material, and it can be uniformly polarized without using any means such as rotating the material to be irradiated. It can be irradiated.

Also, because circularly polarized waves were used to heat the material.

Since uniform heating is possible without overheating the substance as in the conventional method, if the substance is food, the taste is reduced.

It is possible to maintain a state with little change in color.

[Brief explanation of drawings]

1 to 3 are explanatory diagrams showing means for generating circularly polarized waves, FIG. 4 is a schematic explanatory diagram showing an embodiment of the apparatus used in the method of the present invention, and FIGS. 5 and 6 FIG. 1 is an explanatory diagram showing the structure of a conventional heating device. Patent application: Toppan Printing Co., Ltd. Representative: Kazuo Suzuki'

Claims (1)

[Claims] (1) High-frequency heating that irradiates materials with circularly polarized high-frequency waves
Sterilization method.