JPS62153620A - Structure of combustible discharged gas incinerator device using microwave - Google Patents

Abstract

PURPOSE:To enable microwave to be effectively supplied to a microwave absorbing material at a bottom part of an incineration chamber by a method wherein a port of radiation of microwave arranged at a top part of the incineration device is made as a funnel shape and a metallic plate is fixed to an upper furnace wall of a hot incineration furnace chamber. CONSTITUTION:A port 20 for radiation of microwave is made as a funnel shape and a microwave is efficiently supplied to a hot temperature incineration furnace chamber 18 through a microwave transmitting furnace material 17. A metallic plate 21 having a nature of reflecting the microwave is fixed to the upper incineration furnace wall of a hot temperature incineration furnace, the microwave is not absorbed at the upper part of the incineration chamber of hot incineration furnace and the microwave can effectively be supplied to the microwave absorption ceramics furnace material 15 and the furnace bottom plate 16. Therefore, since the bottom part of the hot temperature incineration device is heated to a hot temperature, the processing gas supplied from the bottom part of the incineration furnace starts to ignite at the bottom part, the upper part of the furnace is heated with the combustion heat, so as entire incineration chamber 18 can uniformly be heated up to a hot temperature and the processing gas can be processed better.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an incinerator that uses microwave energy to oxidize, burn, or decompose combustible exhaust gas or exhaust gas containing harmful components.

[Conventional technology and its problems]

Conventionally, when incinerating waste made of polymeric plastic materials, for example, a large amount of flammable gas, tar, etc.
Oil smoke and/or harmful gases are generated. It is difficult to completely burn these in the same incinerator, and in order to burn them completely, the size of the furnace should be large enough to handle the amount of waste, and the temperature inside the furnace should always be kept high. It is difficult to say that incineration using such a torch is an efficient method.

・As a countermeasure for this, in ordinary incinerators, a secondary combustion furnace that can be heated to a high temperature is installed at the outlet of the incineration exhaust gas, and a method is adopted in which the vermilion is completely combusted in this furnace. Although this method is effective, it is necessary to maintain the secondary combustion furnace at a high temperature, which makes the furnace structure complicated, such as installing an auxiliary fuel supply burner, and its control becomes complicated. Ta.

As a means to solve these problems, the present inventors first developed a material that absorbs microwaves in the furnace by irradiating microwaves to a material that absorbs microwaves. We proposed a method of oxidizing or decomposing flammable or harmful components through exhaust gas or exhaust gas containing harmful components, and an incinerator for carrying out the method (Japanese Patent Application No. 59-272067, Utility Application No. 59-195298) , Utility Application No. 59-195300).

This method involves passing flammable exhaust gas or exhaust gas containing harmful components through a furnace that is maintained at a high temperature by irradiating microwaves onto a material that absorbs microwaves, that is, converting the furnace into a secondary combustion furnace. It can be used as
This is a simple device that completely burns unburned substances and completely decomposes the hazardous components that have been broken down.

Next, the previously proposed incinerator and its operating method will be explained with reference to FIGS. 2 and 5.

Figure @2 shows an example of an incinerator, and shows a schematic cross-sectional view of the incinerator, where 1 is an inlet for flammable exhaust gas or exhaust gas containing harmful components, 2 is an outlet for treated exhaust gas, and 3 is a microwave inlet. , 4 is a heat insulating material layer, 5 is a packed layer made of granular, plate-like or block-like material having the property of absorbing microwaves, 6 is a high-temperature furnace chamber, 7 is an upper furnace chamber, and 8 is a large number of holes through which exhaust gas passes. A filler support plate (furnace bottom plate) with holes is shown.

Microwaves applied from the microwave inlet 3 are absorbed by the packed bed 5 made of a granular, plate-like, or block-like material that has the property of absorbing microwaves, and the packed bed is heated to a high temperature. The combustible exhaust gas introduced from the combustible exhaust gas inlet 1 comes into contact with the heated filling material and is heated to a high temperature to almost completely burn the combustible content in the gas in the high temperature furnace chamber 6. I can do it. In addition, by controlling the microwave output, the packed bed can be easily heated to a temperature of 900°C or higher, making it easy to burn tar contained in the exhaust gas from incineration of plastic waste, etc. Furthermore, ammonia, cyanide, etc. contained in the incineration exhaust gas can be easily decomposed.

In the example shown in FIG. 2, the particle size of the microwave absorbing material used as the packed layer may be about 5 sm to 10 sm, and it is sufficient to fill it to a thickness of 100 ++ m to 300 sm. .

Furthermore, in order to prevent microwaves from leaking from the exhaust gas inlet, the furnace bottom plate 8 is also preferably made of a microwave absorbing material.

As microwave absorbing materials, SiC, TiO2, Al2
O2, ilmenite, Fe2O3, S ic+s i3
N4, ZrO2, CaO sand, etc. that absorb microwaves and have heat resistance are used; however, due to their microwave absorption characteristics, SiC, TiO2, ilmenite,
BaTiO3 or Fe203, especially 5iC1Ti02
is preferred.

Next, we installed a third incinerator of a different type than the one shown in Figure 2.
As shown in the figure.

In FIG. 3, reference numeral 11 indicates an inlet of flammable exhaust gas or an exhaust gas containing toxic components, 12 indicates a treated exhaust gas outlet, and 1
3 is a microwave pipe, 14 is a heat insulating material, 15 is a furnace wall made of a microwave absorbing material, 16 is a furnace bottom plate with an exhaust gas passage made of a microwave absorbing material, and 17 is a combustion gas passage. A perforated plate made of a microwave permeable heat resistant material, 18 is a high temperature furnace chamber, and 19 is an upper furnace chamber.

The microwave applied from the microwave introduction 'f11s passes through the microwave-transparent heat-resistant material porous plate 17 and is absorbed by the wall 15 and the furnace bottom plate 16 made of microwave absorbing material in the high-temperature furnace chamber 18. As a result, Since the walls and the furnace bottom plate are heated to a high temperature, the inside of the high-temperature furnace chamber 6 becomes high temperature due to the radiant heat.

The combustible gas introduced from the combustible exhaust gas inlet is heated to a high temperature by the radiant heat, and the combustibles in the exhaust gas are combusted by the oxygen contained in the exhaust gas, after which it is discharged through the upper furnace chamber 19. He wandered through exit 12.

A perforated plate 17 made of a microwave-transparent heat-resistant material provided in the upper part of the high-temperature furnace chamber 18 is for improving the heating effect of radiant heat in the high-temperature furnace chamber, and the perforated plate 17 may be omitted. As the material of the perforated plate 17, quartz, silicon nitride, etc. can be used, and a material having a property of absorbing microwaves to some extent, such as a material made of alumina, may also be used.

[Problem that the invention seeks to solve]

In the above-mentioned incinerator that uses microwave energy, ■ Because the microwave waveguide is directly attached to the top of the furnace, it is difficult for microwaves to be efficiently introduced into the furnace, and ■ Microwaves irradiated into the high-temperature furnace chamber are Most of the gas is absorbed in the upper part of the furnace chamber, so the temperature distribution inside the furnace chamber is low at the bottom (high at the top), which has the disadvantage that the process gas cannot be processed efficiently in the furnace chamber.

[Failure to solve the problem]

The present invention has been made in order to eliminate the above-mentioned drawbacks, and the present invention has been made to remove flammable gas or In a furnace that oxidizes, burns, or decomposes combustible or harmful components through gas containing harmful components, the microwave irradiation port provided at the top of the furnace is shaped like a trumpet so that microwaves can be uniformly introduced throughout the room. In addition, the microwave irradiation port provided at the top of the furnace has a trumpet-like shape, and a metal plate is attached to the upper furnace wall of the high-temperature furnace chamber, so that microwaves are transmitted through the microwave absorbing material at the bottom of the furnace chamber. It is designed to be able to effectively supply microorganisms, and to make efficient use of micro-numbers.

Hereinafter, the present invention will be explained in detail based on FIG.

FIG. 1 shows an incinerator in which the present invention is applied to the incinerator shown in FIG. 5. The same reference numerals as those in FIG. This portion also serves as the upper furnace chamber 19, and 21 indicates a metal plate attached to the upper wall of the high temperature furnace chamber 18. In the incinerator shown in Fig. 1, the ceramic furnace material that absorbs microwaves is provided only in the lower part of the high-temperature furnace chamber, but if the metal plate 21 is not attached, it is similar to the incinerator shown in Fig. 3. It goes without saying that it may also be provided on the upper wall surface of the high temperature furnace chamber.

The operating method of the incinerator shown in Fig. 1 is exactly the same as that explained with reference to Fig. 3, but in the incinerator shown in Fig. 1, the microwave irradiation port is shaped like a trumpet, so that the microwave Waves are efficiently supplied to the high-temperature furnace chamber through the microwave transmission furnace material 17, and a metal plate that reflects microwaves is attached to the upper furnace wall of the high-temperature furnace chamber.
This technology allows microwaves to be effectively supplied to the microwave-absorbing ceramic furnace material and the microwave-absorbing ceramic furnace bottom plate that make up the lower wall of the high-temperature furnace chamber without being absorbed in the upper part of the high-temperature furnace chamber. Because the bottom is heated to a high temperature, the processing gas supplied from the bottom of the furnace starts burning at the bottom, and this combustion heat heats the top of the furnace.
Since the entire high-temperature furnace chamber can be brought into a substantially uniform high-temperature state, the processing gas can be processed satisfactorily.

Example 1 A stainless steel μ plate with a width of 90 strips is attached to the inner periphery of the upper furnace wall of a high temperature furnace chamber with a diameter (inner diameter) of 200 m + and a height of 320 m, and a trumpet-shaped microwave irradiation port with a height of 350 m is attached at the top. Using a pilot test furnace with the structure shown in Figure 1, the microwave output from the microwave generator was set to 3 kW, and microwaves were irradiated to heat the core of the furnace to approximately 900°C.
After heating it to It became 50 ppm or less.

In this incinerator, 95 or more of the incident microwaves could be supplied to the high-temperature furnace chamber, but in the furnace shown in Figure 3, only about 80% of the incident microwaves could be supplied to the high-temperature furnace chamber. Moreover, since the upper part of the high-temperature furnace chamber is heated, in order to obtain the same combustion efficiency as above, it was necessary to set the microphone mouth wave output of the microwave generator to about 5 kW.

Similar results can be obtained when a metal plate is attached to the wall of the high-temperature furnace chamber in an incinerator as shown in FIG. 2, and a trumpet-shaped microwave irradiation port is provided at the top.

〔Effect of the invention〕

According to the present invention, it is possible to efficiently supply microwaves to an incinerator.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a secondary incinerator illustrating an embodiment of the present invention, and FIGS. 2 and 3 are schematic cross-sectional views of a conventional incinerator. 1.11... Inlet of exhaust gas to be treated, 2.12... Outlet pipe of treated exhaust gas, 3, 13... Microwave introduction pipe, 4, 14... Insulating material, 5... Filling Layer, 6...
High temperature furnace chamber, 8, 16... Furnace bottom plate, 15... Furnace wall, 1
8...High temperature furnace chamber, 20-...Trumpet-shaped microwave irradiation port, 21...Metal plate Fig. 1 Fig. 2■ Fig. 3

Claims (1)

[Claims] 1. Combustible gas or exhaust gas containing harmful components is passed through a furnace that is maintained at a high temperature by irradiating microwaves to a material that absorbs microwaves in the furnace. A microwave combustible exhaust gas incinerator for oxidative combustion or decomposition of components or harmful components, characterized in that a microwave irradiation port at the top of the furnace is shaped like a flap. 2. The incinerator according to claim 1, wherein the surface of the furnace material above the microwave absorbing material in the furnace is covered with a metal plate.