JPH0286094A - Microwave heater - Google Patents

Abstract

PURPOSE:To uniformly heat an object to be heated in the stationary state by changing the mode attitude to the TE mode or TM mode in turn in an applicator. CONSTITUTION:A loop 4 is provided on the circular coupling port of the connection section between an applicator 1 and a circular wave guide 2, thereby it can be optimumly coupled with both the electric field and the magnetic field. When the direction of the electric field in the circular wave guide 2 is changed by rotating a mode separator 5 with a motor 6, TE mode coupling is performed if the direction of the electric field in a coupling wave guide 3 is vertical, TM mode coupling is performed with the magnetic field coupling by the loop 4 if it is horizontal, and the location of the maximum electric field in the applicator 1 is repeatedly changed. An object to be heated in the stationary state in the applicator 1 is uniformly heated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a microwave heating device that uniformly heats an object to be heated in a fixed state within a resonant microwave heating applicator.

[Conventional technology]

In order to uniformly heat an object within a resonant microwave heating applicator, moving or rotating the object to be heated is an extremely effective means. It may not be possible.

Conventionally, when heating an object in a fixed state, uniform heating has been attempted by adjusting the shape and tuning of the applicator, but good results have not been obtained.

Also, like a microwave oven, a rotating reflector (stirrer)
There is a method of rotating the applicator within the applicator, but in the case of a resonant open type, it is generally difficult to do so due to dimensional constraints, and this is a factor that impedes the resonance conditions.

[Problem to be solved by the invention]

Conventionally, as described above, when heating an object in a fixed state, it is difficult to uniformly heat the object, and there is a problem in that there are areas where heating is insufficient.

The present invention was made to solve the above problems.
It is an object of the present invention to provide a device that can uniformly heat an object to be heated in a fixed state.

[Means to solve the problem]

In the microwave heating device of the present invention, the input part of a resonant microwave heating applicator is a circular waveguide, and the circular waveguide is coupled to the applicator through an opening (electric field coupling) and a loop (magnetic field coupling). and inserting a mode separator into the circular waveguide into a structure rotatable around an axis, rotating the mode separator to alternately convert the mode configuration in the applicator into a TE type and a TM type. The heating of the dielectric material is carried out in a place in the resonator where the electric field is strong.
This method takes advantage of the fact that the position of this maximum electric field point changes depending on the mode.

〔Example〕

FIG. 1 is an explanatory diagram showing the configuration of an embodiment of the present invention, in which 1 is a resonance type microwave heating applicator, 2 is a circular waveguide for microwave input coupled to the applicator 1, and 3 is a circular waveguide for microwave input coupled to the applicator 1. Coupling waveguide, 4 is magnetic field coupling loop, 5 is circular waveguide 2
A mode separator is inserted into a rotatable structure centered around the entire shaft, 6 is a motor, and 7 is a rotary motion transmission mechanism composed of gears and the like.

The operation will be explained below.

The electric field in the standard rectangular waveguide shown in Figure 2(a) is H
01 mode determines the direction, but the corresponding figure 2 (
The electric field in the circular waveguide shown in b) is generated in the H11 mode, and its direction is not constant.

In addition, in the case of a circular waveguide, in addition to the H11 mode, '
Since modes such as Eol and Hol are likely to occur, H4,
In order to generate a mode, a mode separator as shown in FIG. 3 must be inserted to generate an electric field in only one direction.

To couple the waveguide to the cavity resonator 5, it is most efficient to couple the opening of the waveguide to the electric field at a position where the electric field strength of the desired mode of the cavity resonator is maximum. is also effective, but
As shown in Figures 4 and 5, the position is 0 from one end in TM mode, and when voltage is coupled to the cavity resonator with one coupling port, either TE or TM It is valid only in mode.

When electric field coupling is performed for the mode, the electric field becomes the minimum point for the TM mode, and almost no electric field coupling is performed in this mode.

However, in any mode, at the maximum electric field point, the magnetic field is maximum in the TM-q mode.

In coupling the waveguide and the cavity resonator, the electric field is coupled by an aperture, but the magnetic field coupling can be realized by a loop as shown in FIG.

Therefore, as shown in FIG. 1, by installing the loop 4 at the circular coupling port of the coupling portion between the applicator l and the circular waveguide 2, it is possible to optimally couple both the electric field and the magnetic field.

When the direction of the electric field in the circular waveguide 2 is changed by rotating the mode separator 5 by the motor 6, TE mode coupling is performed when the direction of the electric field in the coupling waveguide 3 is longitudinal. When in the horizontal direction, TE is achieved by magnetic field coupling due to the loop f4.
Since mode coupling occurs and the location of the maximum electric field within the applicator 1 changes repeatedly, the object to be heated fixed within the applicator 1 is heated uniformly.

〔Effect of the invention〕

As described above, according to the present invention, uniform heating of a fixed object to be heated can be achieved far more effectively than conventional devices.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the configuration of an embodiment of the present invention, Fig. 2 (a) and (b) are explanatory diagrams showing an example of the direction of the electric field in the waveguide, and Fig. 3 is an explanatory diagram showing an example of the direction of the electric field in the waveguide. An explanatory diagram showing an example,
FIGS. 4 and 5 are explanatory diagrams showing an example of effective coupling of a waveguide to a cavity resonator, and FIG. 6 is an explanatory diagram showing an example of a magnetic field coupling loop. 1... Applicator for microwave heating of a resonator, 2.
...Circular waveguide, 3...Coupling waveguide, 4...Loop, 5...Mode separator, 6...Motor, 7...Rotational motion transmission mechanism Fig. (a) b) Figure 7M mode Figure 4 Electric field E 7M mode Figure 4

Claims (1)

[Claims] a resonant microwave heating applicator; a microwave input circular waveguide electrically coupled to the applicator and magnetically coupled in a loop; a mode separator inserted into the structure;
a means for driving and rotating the mode separator, and capable of alternately converting the mode attitude in the applicator into a TE type and a TM type.