JP3843783B2 - Microwave melting equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a microwave melting apparatus that melts a material to be melted such as incinerated ash using microwave heating.
[0002]
[Prior art]
A conventional incineration ash treatment apparatus of this type is disclosed in, for example, Japanese Patent Laid-Open No. 10-54539. In this publication, an incineration ash treatment apparatus as shown in FIG. 5 is described, and the shape of the incineration ash reaction chamber as shown in FIG. 6 is described. Here, the mixture of aluminum powder and metal oxide is called thermite, and the thermite / incineration ash mixing section 1 is composed of a mixing / stirring section 5 and a feeder 6 for feeding the incineration ash mixture. The mixing / stirring unit 6 has a stirring container 7 for adding the thermite, incineration ash, and binder and a stirring blade 8, and these are uniformly stirred and mixed to obtain an incineration ash mixture. The feeder 6 is formed by a screw conveyor or the like that supplies the incinerated ash mixture to the compression / solidification unit 2, and is agitated and mixed in the conveying process by this conveyor to make the thermite and the incinerated ash uniform. The bottom surface 7 a of the stirring vessel 7 is inclined and smoothly supplies the incinerated ash mixture to the delivery unit 3.
[0003]
The delivery unit 3 includes a screw conveyor 15 and a delivery passage 16, and the delivery passage 16 is formed with a narrow passage width c on the combustion / melting unit 4 side. The combustion / melting section 4 is for burning and melting the incinerated ash mixture, and is composed of a refractory furnace body 20. A cylindrical incineration ash melting chamber 21 is provided at the center of the refractory furnace body 20, and a microwave heating device or induction heating device is provided between the refractory furnace body 20 and the incineration ash melting chamber 21. A heating chamber 22 is formed. The refractory furnace body 20 is made of, for example, a refractory material such as SiO2-Fe2O3-Al2O3-CaO-MgO.
[0004]
The incineration ash melting chamber 21 has a preheating chamber 24 and a reaction chamber 25, the preheating chamber 4 is connected to the delivery passage 16 of the delivery unit 3 of the incineration ash mixture, the reaction chamber 25 is detachably attached to the preheating chamber 24, and It is attached so that it can rotate freely. The reaction chamber 25 and the heating chamber 22 are configured to be freely opened and closed by a fireproof lid 26 of the fireproof furnace body 20, and an incinerated ash mixture introduced into the reaction chamber 25 is ignited in a part of the fireproof lid 26. There are provided an ignition source insertion port for inserting an ignition source (burner or the like) and a molten slag recovery port for taking out the molten incinerated ash mixture, that is, molten slag. The preheating chamber 24 and the reaction chamber 25 are made of a refractory material similar to that of the refractory furnace body 20, and a passage through which the incinerated ash mixture is introduced and circulated is formed. The preheating chamber 24 has a cylindrical shape, and the reaction chamber is a kind of crucible. The crucible is laid down sideways, its bottom portion is opened to communicate with the preheating chamber 24, and molten slag can be collected from the front end side of the crucible. It has become.
[0005]
The heating chamber 22 is provided with a microwave heating device or an induction heating device. As this microwave heating apparatus or induction heating apparatus, a melting furnace or the like that is usually used as a heating apparatus for melting is used. By this heating device, the incinerated ash mixture in the preheating chamber 24 can be preheated, and the temperature of the reaction chamber 25 can be raised to adjust and promote the combustion / melting state of the incinerated ash mixture. Further, as shown in FIG. 6, the reaction chamber 25 has a structure in which a crucible is laid down, and a taper 28 is formed at the tip of the reaction chamber 25 so that the molten slag flows easily. The reaction chamber 25 is provided with an oxygen supply port, and a water tank 30 for recovering as slag is installed below the molten slag recovery port.
[0006]
Now, as shown in FIG. 5, the conventional incineration ash treatment apparatus is a thermite by driving the stirrer stirrer with the thermite, incineration ash and binder into the stirring vessel 7 of the mixing / stirring unit 5. Etc. are stirred and mixed to obtain a powdered incineration ash mixture. This incinerated ash mixture is supplied to the incineration ash mixture delivery unit 2 through a chute 11 and a rotary valve 12 provided at the lower part of the stirring vessel 7, and the incineration ash is passed through the incineration ash solid matter delivery passage 16 by the screw conveyor 15. It is sent in the direction of the combustion / melting section 4 of the mixture and introduced into the refractory furnace body 20. Here, the microwave heating apparatus or induction heating apparatus of the refractory furnace body 20 is turned on so that the combustion gas heats the incineration ash melting chamber 21. The incinerated ash mixture is introduced into the melting chamber 21, introduced into the next reaction chamber 25 while being preheated, and when ignited, the room temperature of the reaction chamber 5 rises due to the heat from the heating chamber 22, but up to about 1100 ° C. Then, the incinerated solid material starts to burn due to the thermite reaction and reaches about 2750 ° C. by the reaction heat, and the incinerated mixture is melted into slag and recovered from the molten slag recovery port.
[0007]
[Problems to be solved by the invention]
As described above, in the conventional incineration ash treatment apparatus, in the process of heating the melt and raising the temperature, when the gas is released from the melt and irradiated with microwaves, Although discharge may occur, the plasma formed by this discharge has the property of reflecting microwaves, and thus there is a problem that the propagation of the microwaves is hindered and the heating efficiency may be reduced.
Therefore, the present invention has been made to solve such a problem. Gases are released from a melted material in advance, and plasma generation is suppressed during microwave irradiation to improve heating efficiency. An object is to provide a novel microwave melting apparatus.
[0008]
[Means for Solving the Problems]
The microwave melting apparatus according to claim 1 is a tank for charging a material to be melted, a transport unit for transporting the material to be melted in the tank, and a material to be melted transported by the transport unit at the top. And a chute that is inclined so as to be taken out from the lower end, a heating unit that surrounds the chute and heats the melt, and a hydrocarbon gas that is released by heating the melt by the heating unit. A blower having a filter that discharges to the outside from the upper end of the chute, a melting container that is disposed near the lower end of the chute and that stores a melted material that has released hydrocarbon gas, and a melted material that is stored in the melting container A microwave generating means for generating a microwave for irradiating the object, and a microwave generated by the microwave generating means for irradiating the molten material from which the hydrocarbon gas is released in the melting vessel; A mirror for changing the direction of microwave to, in which a collecting container for collecting the chamber to shield the external emission of microwaves by receiving at least the mirror, the slag generated in the melting vessel.
[0009]
The microwave melting apparatus according to claim 2 is a tank for charging a material to be melted, a transport unit for transporting the material to be melted in the tank, and a plurality of materials for storing the material melted by the transport unit. Melting means, moving means for placing and moving these melting containers intermittently, heating means for sequentially heating the material to be melted stored in each melting container moved by the moving means, A blower having a filter that discharges hydrocarbon gas released from the melt by being heated by the heating means, and a melt that is conveyed by the moving means and released hydrocarbon gas by the heating means and the blower A microwave generating means for generating a microwave to be irradiated to the melted material in the container, and a hydrocarbon gas in the melting container is used to generate the microwave generated by the microwave generating means. A mirror that changes the irradiation direction of the microwave so as to irradiate the melted material, a chamber that houses at least the mirror and shields the external radiation of the microwave, and a recovery that collects the slag generated in the melting container And a container.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic configuration diagram for explaining the microwave melting apparatus according to the first embodiment. FIG. 2 is a configuration diagram of the apparatus shown in FIG. 1 when viewed from the left side. In FIGS. 1 and 2, 40 is a tank for charging a material to be melted, 41 is a heater heating device for heat-treating the material to be melted into the tank 40, 42 is a heat insulating material, and 43 is from the screw conveyor 15. A chute 44 for guiding the melted material to be carried out is a ceramic melting container for temporarily storing the melted material guided by the chute 43 and irradiating it with microwaves.
[0018]
45 is a microwave generator such as a gyrotron for generating a microwave, 46 is a microwave generator 45, for example, a magnetic field generator such as a coil for forming a magnetic field in the gyrotron, and 47 is a microwave generator. An antenna that radiates microwaves emitted from 45 into the air, 48 receives and reflects the microwaves radiated from antenna 47, and a focusing mirror for narrowing the focal point, and 49 reflects the microwaves It is a plane mirror. Reference numeral 50 denotes a first chamber which houses the antenna 47, the focusing mirror 48 and the plane mirror 49 and shields microwaves to some extent. Reference numeral 51 denotes a second chamber for housing the first chamber 50, the melting container 44, and the like to completely shield the microwave as shown in FIG. As shown in FIG. 2, 52 is a support base that supports the melting container 44 and the heat insulating material 42, and 53 is a blower that filters the air in the second chamber 51 and discharges it to the outside. Reference numeral 54 denotes a microwave propagation path.
[0019]
In the microwave melting apparatus as shown in the first embodiment, the material to be melted introduced from the tank 40 is conveyed by the screw conveyor 15 and passes through the heater heating device 41. Since the heater heating device 41 is heated in advance to about 900 ° C., the melted material is rapidly heated immediately after entering the heater heating device 41, and the temperature rises to 800 ° C. or more in about 2 minutes. In the course of this temperature increase, mainly hydrocarbon gases such as methane and propane are released from the melt. These generated gases are discharged to the outside in a state where dust is scraped off by a blower 53 equipped with a filter. Here, this process is called heat treatment. The material to be melted after the heat treatment is conveyed to the end point of the screw conveyor 15 and is poured into the melting container 44 by the chute 43. On the other hand, a microwave generated by, for example, a gyrotron is radiated from the antenna 47 into the air, and the direction is changed by the focusing mirror 48, and at the same time, the microwave is narrowed down and enters the melted object in the melting container 44.
[0020]
Therefore, the material to be melted is heated and melted by the incident microwave. In the case of irradiating the heat-treated melt with microwaves, plasma is hardly generated and there is nothing to prevent the propagation of microwaves, so that the microwave power is efficiently supplied to the melt. The slag generated by melting is accumulated in the melting container 44. After a certain amount of accumulation, the melting container 44 is provided with a flow outlet, so that it flows out from the flow outlet and is collected in the recovery container 30. As described above, according to the first embodiment, since the microwave is hardly irradiated to the hydrocarbon gas released from the melt and the plasma is hardly generated, the microwave is efficiently irradiated to the melt. be able to. In addition, if heating is performed by irradiating microwaves to a high-temperature melt immediately after heat treatment, it is possible to save electric power for microwave heating.
[0021]
Embodiment 2. FIG.
Next, Embodiment 2 will be described with reference to FIG. FIG. 3 is a block diagram corresponding to FIG. In FIG. 3, reference numeral 55 denotes a chute, which is inclined downward from the upper end toward the lower end as shown in FIG. As in the case of the first embodiment, the material to be melted put into the tank 40 is conveyed by the screw conveyor 15 and put into the upper end of the chute 55. A vibrator 56 is attached to the chute 55. Accordingly, since the chute 55 is appropriately vibrated by driving the vibrator 56, the melted material moves smoothly to the lower end of the chute 55. 41 is a heater heating device and 42 is a heat insulating material. The chute 55 is disposed inside the heater heating device 41, while the heater heating device 41 is disposed along the inclination direction of the chute 55.
[0022]
Thus, in Embodiment 2, since the chute 55 is arranged inside the heater heating device 41, the melted material is heated while moving the chute 55, and mainly hydrocarbon gas is used. discharge. The released hydrocarbon gas is discharged to the outside by the blower 53 through a duct disposed near the upper end of the chute 55. The to-be-melted material for which the heat treatment has been completed is put into the melting container 44 from the lower end of the chute 55, where microwaves are irradiated, and the generated slag is recovered in the recovery container 30. The point of irradiating the slag accumulated in the melting container 44 through the focusing mirror 48 and the plane mirror 49 is the same as in the case of the first embodiment. In FIG. 3, reference numeral 10 denotes a motor for driving the screw conveyor 15. As described above, according to the second embodiment, as in the case of the first embodiment, the hydrocarbon gas released from the melt is hardly irradiated with microwaves, so that plasma is hardly generated. Waves can be efficiently applied to the melt.
[0023]
Embodiment 3 FIG.
Furthermore, Embodiment 3 will be described with reference to FIG. FIG. 4 is a configuration diagram for explaining the third embodiment. In FIG. 4, 60 is a heat insulating shutter for keeping the inside of the heater heating device 41, 61 is a stirring device for stirring the material to be melted in the melting vessel 44 and shortening the heating time, and 62 is the melting vessel 44. An extruding device 63 for extruding the inner slag, 63 is a slag collection chute for conveying the slag extruded by the extruding device 62 to the collection container 30. Now, the material to be melted introduced into the tank 40 is introduced into the upper end (one end) of the screw conveyor 15 and conveyed, and is introduced into the melting container 44 from the lower end (the other end). A plurality of ceramic melting containers 44 are arranged and moved intermittently from the left side to the right side in FIG.
[0024]
That is, in the time zone in which the material to be melted is put into the first melting container 44 at the left end in FIG. 4, the heat insulating conveyor is stopped and the heat insulating shutter 60 is closed. In this time zone, the melted material in the second melting container 44 is heated by the heater heating device 41 while being stirred by the stirring device 61. The third melting container 44 is also heated by the heater heating device 41. The material to be melted in the second and third melting containers 44 releases hydrocarbon gas by this heating, but the hydrocarbon gas is discharged to the outside by the blower 53. Further, in the time zone, the object to be melted in the fourth melting container 44 is irradiated with the microwave from the antenna 47 via the focusing mirror 48. Further, the slag in the seventh melting container 44 is pushed out by the pushing device 62 and collected in the collecting container 30.
[0025]
In this way, at the time when the work of charging the melt, the heating by the heater heating device 41, the microwave irradiation, and the slag recovery are completed, the heat insulating shutter 60 is opened and the heat insulating conveyor is moved. Driven to move each melting vessel 44 for the next operation. The seventh melting container 44 is arranged at the position of the first melting container 44 after the slag is pushed out. At this time, the insulated conveyor is stopped and the above-described operation is repeated. As described above, according to the third embodiment, plasma is hardly generated by irradiating the hydrocarbon gas released from the melt with microwaves, as in the first and second embodiments. The object to be melted can be efficiently irradiated with microwaves.
[0026]
【The invention's effect】
As described above, according to the present invention, the hydrocarbon gas released from the melt is hardly irradiated with microwaves and plasma is hardly generated. Therefore, the microwave that can efficiently irradiate the melt with microwaves. There is an effect that a wave melting apparatus can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram for explaining a microwave melting apparatus according to a first embodiment.
FIG. 2 is a configuration diagram when the apparatus shown in FIG. 1 is viewed from the left side.
FIG. 3 is a configuration diagram corresponding to FIG. 2 in the second embodiment.
FIG. 4 is a configuration diagram for explaining a third embodiment;
FIG. 5 is a configuration diagram showing a conventional incineration ash treatment apparatus.
FIG. 6 is a configuration diagram showing the shape of an incineration ash reaction chamber in a conventional incineration ash treatment apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 15 ... Screw conveyor, 30 ... Collection | recovery container, 40 ... Tank, 41 ... Heater heating device, 42 ... Heat insulating material, 43 ... Chute, 44 ... Melting container, 45 ... Microwave generator, 46 ... Magnetic field generator, 47 ... Antenna 48 ... focusing mirror, 49 ... planar mirror, 50 ... first chamber, 51 ... second chamber, 52 ... support, 53 ... blower, 54 ... microwave propagation path, 55 ... chute, 56 ... vibrator , 60 ... heat insulating shutter, 61 ... stirring device, 62 ... extrusion device, 63 ... slag recovery chute

Claims (2)

  A tank for charging the molten material, a conveying means for conveying the molten material charged into the tank, and an inclination so that the molten material conveyed by the conveying means is charged at the upper end and taken out from the lower end. And a heating means for heating the material to be melted surrounding the chute, and a filter for discharging the hydrocarbon gas released by heating the material to be melted by the heating means to the outside from the upper end portion of the chute A blower having the above, a melting container that is disposed near the lower end of the chute and stores a melted material that has released hydrocarbon gas, and a microwave generator that generates microwaves to irradiate the melted material stored in the melting container And the microwave irradiation direction is changed so that the microwave generated by the microwave generation means is irradiated to the melted material from which the hydrocarbon gas in the melting container is released. Ra and the chamber to shield the external emission of microwaves by receiving at least the mirror, a microwave melting apparatus being characterized in that a collecting container for collecting the slag generated in the melting vessel.   A tank for charging a material to be melted, a transport means for transporting the material to be melted put into the tank, a plurality of melting containers for storing the material to be melted transported by the transport means, and these melting containers are mounted. A moving means that is moved intermittently, a heating means that sequentially heats the melt contained in each melting container moved by the moving means, and a heating means that is heated by the heating means and A blower having a filter that discharges the released hydrocarbon gas to the outside, and a micro that is conveyed by the moving means and that irradiates the melted material in the melting container from which the hydrocarbon gas is released by the heating means and the blower. Microwave generating means for generating a wave, and a microwave generated by the microwave generating means so as to irradiate the melted material from which the hydrocarbon gas is released in the melting vessel. A micro comprising: a mirror that changes the direction of irradiation of chrominance waves, a chamber that houses at least the mirror and shields external radiation of microwaves, and a collection container that collects slag generated in the melting container Wave melting device.

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