JPH07332631A - Electromagnetic wave heating device - Google Patents

Abstract

PURPOSE:To provide an electromagnetic wave heating device capable of performing an efficient heating by extracting moisture oozing out of a heated item. CONSTITUTION:A micro-wave is guided from a magnetron of a micro-wave generating device to a wave guide 2. The wave guide 2 is arranged vertically and an output of a micro-wave is guided from a lower part to an upper part. A wedge type container 3 having a low dielectric loss is installed downward in the midway of the wave-guide 2. A heated item 4 is set in the container. There is a hole at the bottom part of the container. To the hole is connected a water discharging hose 6 of low dielectric loss. The water drain hose is guided out of the device through a wave guide 7 in a shut-off mode. As this container, a comical shaped container, a rectangular pyramid shaped container and a cup-shaped container having a downward protruded shape beside the wedge- shaped container may be used. There is provided a lid of electromagnetic wave shielding structure for passing gas but shielding and electromagnetic wave, a punched metal 5 is installed at the extremity end of the wave guide. This device can heat efficiently even the substances having a wide induction rate such as substance of water and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for heating an object using electromagnetic waves including microwaves. Especially suitable for drying raw materials.

[0002]

2. Description of the Related Art A heating device using microwaves is already widely used in industrial and domestic microwave ovens. When a substance having a large dielectric loss, such as water, is exposed to microwaves, heat is generated in proportion to the magnitude of the dielectric loss, thereby heating the substance. Many heating devices (for example, reference: “Nikkei New Material March 30, 1992)
(Japanese issue, p. 87), as shown in FIG.
A turntable 10 is placed inside, and an object to be heated is placed on it and rotated. Since the microwave is irregularly reflected on the metal wall surface in the applicator 11 to irradiate the object, the microwave is not sufficiently absorbed by the object and is largely reflected.

Therefore, in order to perform efficient heating, an applicator as shown in FIG. 4 (comparative example) has been filed by the applicant of the present application in Japanese Patent Application No. 6-9029. In this case, the object to be heated is placed in a container with a low dielectric loss having a downward convex shape, such as a wedge shape or a pyramid shape, and microwaves are radiated from below, so that the reflection can be reduced and the efficiency is very high. It can be heated well.

[0004]

However, in the downward convex container as shown in FIG. 4, the water exuding from the object to be heated is collected in the convex tip portion, and the separated water is purposefully evaporated by the microwave. Since it must be done, it consumes unnecessary energy for heating.

It is an object of the present invention to provide an electromagnetic wave heating device which can realize more efficient heating without the above drawbacks.

[0006]

An electromagnetic wave heating device of the present invention has an electromagnetic wave generator, a waveguide for guiding electromagnetic waves, and a container for containing an object to be heated, said container being non-magnetic and having a low dielectric loss. A downwardly convex shape, located in the waveguide, the convex direction of the container is arranged to face the direction of the electromagnetic wave, and the container has a conical shape, a pyramidal shape, or a wedge shape. Type or bowl type, there is a hole at the tip of the container, and a hose made of low dielectric loss is connected to the hole,
The hose is characterized in that it is drawn out of the device from the waveguide through a waveguide having a cut-off structure at a position below the tip.

[0007] Also, whether the connection of the hose at the bottom of the heating container is covered with a net made of low dielectric loss, or a net-shaped inner container made of low dielectric loss is placed inside the heating container and the object to be heated is placed therein. The feature is that things are put in.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an electromagnetic wave heating apparatus showing an embodiment of the present invention. Microwaves are guided from the magnetron of the microwave generator 1 to the waveguide 2. The waveguide 2 is arranged vertically, and the microwave output is guided from the bottom to the top. Waveguide 2
A wedge-shaped container 3 made of resin having a low dielectric loss is placed downward in the middle of, and an object 4 to be heated is put therein. A hole is formed in the bottom of the container, and a drain hose 6 made of resin, which is also made of low dielectric loss, is attached. On the other hand, the waveguide 2 has a rectangular cross section, but has a hole through which the drain hose 6 is inserted in the surface including the short side thereof. The hole is located below the tip of the heating container so that it does not interfere with the free fall of water. A cutoff mode waveguide 7 is attached to the hole so that microwaves do not leak, and the drain hose 6 is guided to the outside of the device through the cutoff mode waveguide 7. At the end of the waveguide, there is a lid of punching metal 5 that allows gas to pass but shields electromagnetic waves.

In some cases, it is necessary to cover the tip of the container with a mesh hose lid 8 as shown in FIG. 2 so that the drainage hose 6 is not clogged with the object to be heated.

Further, as shown in FIG. 3, by installing the net-shaped inner container 9 inside the heating container, the efficiency of draining can be improved, and more efficient heating can be realized.

The feature of the present invention resides in that a drainage channel for draining water is provided at the bottom of the heating vessel having a low dielectric loss which is convex downward. Moisture that has exuded from the object to be heated collects at the tip of the convex shape, but by discharging the moisture out of the heating container through the drainage channel, it is possible to suppress the consumption of energy without evaporating with microwaves. The heating time can be shortened.

[0012]

EFFECT OF THE INVENTION By using the electromagnetic wave heating device of the present invention, the effect is particularly great when a substance containing a large amount of water is dried by heating, and the exuded water is guided to the outside of the device without being evaporated by the microwave. As a result, the drying time is greatly shortened and the power consumption is greatly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an electromagnetic wave heating apparatus showing an embodiment of the present invention.

FIG. 2 is a view showing a wedge-shaped container and a mesh hose lid as another embodiment of the present invention.

FIG. 3 is a view showing a wedge-shaped container and a net-shaped inner container as another embodiment of the present invention.

FIG. 4 is a diagram showing a structure of an electromagnetic wave heating device having a wedge-shaped container of a comparative example.

FIG. 5 is a diagram showing a structure of a conventional microwave oven.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electromagnetic wave generator 2 Waveguide 3 Wedge-shaped container 4 Object to be heated 5 Punching metal 6 Drain hose 7 Waveguide in cut-off mode 8 Reticulated hose lid 9 Reticulated inner container 10 Turntable 11 Applicator

Claims (3)

[Claims] 1. An electromagnetic wave generator, a waveguide for inducing an electromagnetic wave, and a container for containing an object to be heated, the container having a non-magnetic, low dielectric loss, and convex shape. The container is located inside, the convex direction of the container is opposed to the electromagnetic wave direction, and the shape of the container is a conical shape, a pyramidal shape, a wedge shape, or a bowl shape, and a hole is formed in the bottom of the container. The electromagnetic wave heating device is characterized in that a drainage hose made of low dielectric loss is connected to the drainage hose, and the drainage hose is guided to the outside of the device through a cut-off mode waveguide. 2. The electromagnetic wave heating device according to claim 1, wherein a connecting part of the hose of the heating container is provided with a net-like lid made of low dielectric loss. 3. The electromagnetic wave heating device according to claim 1, wherein a net-shaped inner container made of low dielectric loss is provided inside the heating container, and an object to be heated is put therein.