JPH035840Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention is a microwave heating furnace for preventing the molten material in the metal crucible for melting in a microwave heating furnace from overflowing and flowing into the furnace. This invention relates to an indoor hot water level detection device.

(Prior art) Heating and melting of non-metallic substances using the dielectric heating phenomenon caused by microwave irradiation is a so-called volume reduction process, and is used for the treatment of sludge, various industrial wastes, wastes containing radioactive materials, etc. It is becoming widely used for this purpose. This microwave irradiation treatment
Microwaves are introduced into the furnace from a microwave oscillator through a waveguide, and the tuner at the top of the furnace matches the microwaves, and at the same time supplies the material to be processed into a melting crucible (generally made of metal). This is done by

By the way, in the heat melting process, the same crucible is used to supply the material to be processed into the crucible in batches or continuously and heat melt, accumulate,
The heating and melting process continues until the amount of melt produced reaches the allowable limit of the capacity of the crucible.

In such a batch type operation, care must be taken to accurately monitor the level of the melt so that the produced melt does not exceed the capacity of the crucible and flow out of the crucible. Particularly, when the object to be processed contains radioactive substances, the processing equipment must avoid leaking out of the crucible.

It is also possible to suspend an electrode from above in the furnace and detect when the molten metal level of the material to be treated rises and comes into contact with this electrode. If the microwave irradiation is stopped when the temperature reaches that point, there is a problem that the tip of the electrode is buried in the solidified material and cannot be removed.

(Purpose of the invention) This invention was made to solve such conventional problems, and it is possible to reliably detect the hot water level with a simple device and ensure that the material to be treated does not flow out of the crucible. In addition, there is no problem that the sensing body cannot be removed.

(Structure of the device) This device is a batch-type melting type microwave heating furnace, in which at least one electrode faces the inside of the crucible from above, and the electrode is removably fitted to the electrode base. A display device is connected to the electrode, and when the level of the molten material in the crucible rises and comes into contact with the electrode tip, the display device is displayed. It is configured so that it operates.

(Example) In Fig. 1, a furnace body 1 includes a waveguide 2 for transmitting microwaves, a head tuner 3 for matching microwaves, and an exhaust for discharging decomposition dust, fume, etc. generated during melting. A pipe 4 is provided, and a supply pipe 50 is further provided for supplying the material to be processed into the furnace from a hopper 5 for storing the material to be processed. In addition, a metal crucible 6 is located at the bottom of the furnace body 1.
is installed.

A pair of electrodes 7 are attached to the lower end flange 11 of the furnace body 1, and are arranged so that their tips face into the crucible 6 at the same height. A pair of electrodes 7
A power source 78 and a display lamp 9 serving as a display device are connected in series between them.

The flange 11 has, as shown in FIG.
A holder 70 made of an insulator is attached, and the electrode 7
By penetrating this holding body 70, the holding body 7
0 in an insulated state from the flange 11. Each electrode 7 consists of a base 77 made of a conductor and a chip 8 attached to its tip,
A sphere 71 having a diameter slightly larger than the shaft diameter of other parts is formed at the tip of the base 77.
A slit 72 is formed in the sphere 1 so that the diameter of the sphere 71 can be reduced by external force. By fitting the spherical body 71 into the recess 80 of the tip 8, the base 77 and the tip 8 are removably connected.

FIG. 3 shows another embodiment of this invention, in which only one electrode 7 is attached to the flange 11 of the furnace, and this electrode 7 is connected to the crucible 6 via a power source 78 and an indicator lamp 9. . The configuration of the electrode 7 and the configuration of its attachment portion to the flange 11 may be the same as the configuration shown in FIG.

In the above configuration, the material to be processed is continuously supplied from above into the crucible 6 from the hopper 5 through the supply pipe 50 by the feeder, and is sequentially heated and melted by irradiation with microwaves. As a result, a molten material 13 is generated in the crucible 6 and the molten metal level 14 gradually rises, and when a predetermined amount is reached, the molten metal level 14 comes into contact with the tip of the electrode 7. As a result, conduction is established between the pair of electrodes 7 through the melt 13, and the indicator lamp 9 lights up. Therefore, since this display indicates that the melt 13 in the crucible 6 has reached a predetermined amount, the supply of the material to be processed is stopped. The supply of the material to be processed may be stopped automatically in conjunction with the lighting of the indicator lamp 9. In this way, even normally non-conductive objects become conductive when melted, and this is used to detect the hot water level.

In the case of the configuration shown in FIG. 3, when the hot water level 14 comes into contact with the tip of the electrode 7 as the hot water level 14 rises,
The electrode 7 and the crucible 6 are electrically connected through the melt 13, and as a result, the indicator lamp 9 is turned on as described above.
will be lit.

After the molten material 13 has cooled and solidified, the crucible 6 is removed from the furnace body 1 and a new crucible is installed. Since the chips 8 are embedded in the crucible 6, the chips 8 are also taken with them when the crucible 6 is removed. That is, when the crucible 6 is disconnected from the main body 1 and lowered, the chips 8 embedded in the solidified molten material 13 are also pulled downward, while the base 77 is held by the holder 70. Therefore, the sphere 71 at the tip is pulled out from the recess 80 of the chip 8, leaving only the chip 8 in the crucible 6 which is removed. When attaching a new crucible to the furnace body 1, a new chip 8 having the same shape as above is attached to the base 77 from which the chip 8 was removed.

(Effects of the invention) As explained above, this invention uses electrodes placed at predetermined positions to raise the level of the molten material in a batch-type melting type microwave heating furnace. It is possible to accurately detect the molten metal surface without any adverse effects on the detection function due to the physical properties (melting point) or electrical discharge of the object to be processed, and the ability to detect the molten material in the crucible. Overflow to the outside can be reliably prevented,
Furthermore, there is no problem that the sensing body cannot be removed.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of an apparatus showing an embodiment of this invention, FIG. 2 is an enlarged sectional view of an electrode thereof, and FIG. 3 is a schematic explanatory diagram showing another embodiment of this invention. DESCRIPTION OF SYMBOLS 1... Furnace body, 6... Metal crucible, 7... Electrode, 9... Display lamp (display device), 13... Molten material, 14... Molten metal surface.

Claims (1)

[Scope of utility model registration request] In a batch-type melting type microwave heating furnace, at least one electrode faces into the crucible from above, and the electrode is made of an electrode base and an electrode made of a conductive material that is removably fitted to the base. A display device is connected to the electrode, and the display device is activated when the level of the molten material in the crucible rises and comes into contact with the electrode tip. Features: A device for detecting the level of hot water in a microwave heating furnace.