JPH08233232A - Waste treatment method - Google Patents

Abstract

(57) [Summary] [Purpose] To effectively use the energy of combustible waste in general waste while efficiently treating the incineration ash generated during incineration. [Structure] The volume of combustible waste is reduced and solidified into solid fuel, and the solid fuel is pulverized. The incineration ash as a residue generated by incinerating combustible waste is melted in a melting furnace using the crushed solid fuel as a heating fuel source,
Slag. As the melting furnace, a swirling melting furnace is used in which pulverized solid fuel is obliquely blown into the furnace chamber to burn and melt while swirling the fuel and the melt in the furnace chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating waste, and more particularly to a method for incinerating combustible waste and a method for treating incinerated ash discharged as a residue by the incineration.

[0002]

2. Description of the Related Art So-called general wastes other than those designated as industrial wastes are subject to the processing responsibility of local municipalities such as municipalities. Of general wastes, so-called combustible waste that can be burned is usually incinerated at a refuse incinerator. At this time, of the incineration ash generated by incineration of combustible waste, the main ash that fell below the incinerator was
It will be disposed of at the final disposal site. In addition, so-called fly ash that floats up in the incinerator is recovered from the incinerator, then melted in the melting furnace, separated into slag, metal, molten salt, etc., sorted, and recycled respectively, or suitable. Will be disposed of in different places.

On the other hand, so-called coarse dust having a relatively large volume is crushed by a crusher and then sorted, and combustible substances are incinerated together with the above-mentioned combustible dust. The sorted incombustibles are
It is classified into so-called resource waste, which is intended to be reused as resources, and non-resource waste that cannot be reused as resources. The former is, of course, reused as a resource, and the latter is disposed of at the final disposal site in the same way as so-called incombustible waste that cannot be incinerated.

Further, recently, in addition to reducing the volume of combustible materials such as combustible dust and coarse dust, solidified pelletized solid fuel (RDF: Refuse Driven Fuel).
It is also practiced to burn it easily in a combustion furnace. In this way, when combustible dust or the like is made into a solid fuel, high combustion efficiency is obtained and a large amount of heat of combustion is obtained, so that the thermal energy generated by incineration of dust can be effectively used.

[0005]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention In the above-mentioned conventional general waste treatment system, in particular, landfill disposal of incinerated ash generated by incineration of combustible waste is carried out in groundwater systems, rivers, lakes,
The problem of secondary pollution to the ocean or the atmosphere remains. Therefore, in recent years, for the purpose of reducing the volume of the incinerator ash and making it harmless, a melting furnace is also provided together with the incinerator, and the incinerator ash generated from the incinerator is partially melted in the melting furnace.

However, when a melting furnace is installed together with the incinerator and the incinerator ash generated from the incinerator is melted in the melting furnace,
Melting the incineration ash requires another energy source that has a larger amount of heat than combustible waste. Therefore, the consumption of valuable fuel resources and the generation of carbon dioxide accompanying fuel consumption become problems. Further, it cannot be said that the energy used to incinerate combustible waste is effectively used. The present invention has been made in view of such problems in the related art, and an object thereof is to efficiently process the incineration ash generated by the incineration while effectively utilizing the energy of combustible waste.

[0007]

In order to achieve the above-mentioned object, the present invention uses a solid fuel obtained by reducing the volume of combustible dust and solidifying it, and crushing the solid fuel into a swirling melting furnace. While burning inside, the incineration ash generated due to the incineration of combustible waste is melted by the high combustion heat with a large amount of heat generated thereby to reduce the volume and render it harmless.

That is, the waste treatment method according to the present invention reduces the volume of combustible waste and solidifies it into solid fuel, crushes this solid fuel, and incinerates the combustible waste discarded as waste. It is characterized in that the incinerated ash as the generated residue is melted into a slag by melting it in a melting furnace using the crushed solid fuel as a heating fuel source. Here, as the melting furnace, there is used a swirling melting furnace in which pulverized solid fuel is blown into the furnace chamber and the fuel and the melt are burned and melted while swirling in the furnace chamber.

[0009]

In the waste treatment method according to the present invention, as the heat source for melting the incineration ash, the volume of combustible waste is reduced and the solidified solid fuel pulverized product is used. , High combustion heat is obtained, and incineration ash can be melted. As a result, the incinerated ash is slagged, reduced in volume, rendered harmless, and secondary pollution due to disposal, shortage of disposal sites, etc. can be resolved.

Moreover, since the above solid fuel is obtained by reducing the volume of combustible dust and solidifying it, burning it, that is, the burning treatment of the combustible dust also serves. Therefore, the incineration ash can be melted and the combustible waste can be incinerated at the same time. Therefore, an energy source other than general waste is not required, energy saving can be achieved, and extra combustion other than incineration of waste is not required, so that generation of carbon dioxide can be minimized. Furthermore, as the fuel for melting the incineration ash, the pulverized product of the solid fuel obtained by reducing the volume of combustible waste and solidifying it is used, so that the scale of the incinerator can be greatly reduced, It is possible to incinerate combustible waste and melt incinerated ash at the same time.

[0011]

Embodiments of the present invention will now be described specifically and in detail with reference to the drawings. FIG. 1 is a system diagram of a general waste treatment system including a waste treatment method according to an embodiment of the present invention, and a dashed line portion shows the waste treatment method according to the embodiment.

[0012] Of general waste, so-called combustible waste that can be burned is incinerated at a refuse incinerator, and the heat of incineration is
It is used for district heating using steam, etc., or is taken out as electric power by thermal power generation. Incineration ash is generated by incineration of such combustible waste.
Those that fall below the incinerator are generally called "main ash" and those that fly up in the incinerator are called "fly ash". In addition, a part of the combustible waste is reduced in volume and solidified into pellet-shaped solid fuel (RDF: Refuse Driven Fuel).
l). That is, combustible dust is finely crushed, metals such as iron are removed by a magnetic separator and the like, and then compressed and reduced by a commercially available volume reducer to form pellets.

On the other hand, of general waste, so-called coarse dust having a relatively large volume is crushed by a crusher and then sorted, and combustible substances are incinerated together with the above-mentioned combustible dust. A part of the solid fuel is pelletized in the same manner as described above. Of the selected incombustibles, iron-based wastes are selected by a magnetic separator, crushed, and reused as resources.

Of the general waste, so-called incombustible waste that cannot be incinerated is disposed of at the final disposal site without being processed. Furthermore, the resource waste collected by the separate collection is sorted into steel, aluminum, glass, etc. by a sorting machine, and sold to a specialized processing company.

In the present invention, the treatment of the incineration ash generated by the incineration of combustible waste and the incineration treatment of the solid fuel are combined in this treatment system. That is, after pulverizing the pelletized solid fuel obtained by solidifying and reducing the volume of combustible waste, in a melting furnace using the pulverized solid fuel as a heating fuel source, melt the incineration ash, Slag.

FIGS. 2 and 3 show an example of a swirl melting furnace used as a melting furnace for melting the incineration ash. A circular combustion melting chamber 6 is formed inside a furnace wall 1 made of refractory material. At least a part of the inner wall peripheral portion of the combustion melting chamber 6 is formed with a curved surface, and in the illustrated example, the entire circumference of the inner wall peripheral portion of the combustion melting chamber 6 is formed with a circular curved surface. An exhaust gas outlet 5 is provided at the center of the upper portion of the combustion melting chamber 6, and a combustion ash charging port 3 is provided on the side thereof. Further, a fuel injection port 2 is provided on the side of the exhaust gas outlet 5, the fuel injection port 2 is directed obliquely downward with respect to the central axis of the combustion melting chamber 6, and has a circular shape. It is provided along the inner peripheral surface forming the curved surface 6 in the tangential direction. Further, a molten ash discharge port 4 is opened at the side of the bottom of the combustion melting chamber 6.

First, the above solid fuel is pulverized into powder,
The pulverized solid fuel is blown in the tangential direction along the inner peripheral surface of the combustion melting chamber 6 from the fuel injection port 2 of the swirling melting furnace to burn it. Further, the incineration ash is introduced into the combustion melting chamber 6 through the incineration ash charging port 3. The crushed solid fuel burns while swirling in the combustion melting chamber 6 to melt the incineration ash therein. The molten incineration ash becomes slag and is taken out from the molten ash discharge port 4. The combustion exhaust gas is guided to a boiler or the like through the exhaust gas outlet 5 and used as a heat source.

The slag taken out from the molten ash discharge port 4 is discarded at the final disposal site. Also in this swirl melting furnace, so-called fly ash that rises up inside the combustion melting chamber 6 is generated, but this fly ash is recovered at the exhaust gas outlet 5 and reprocessed. Here, as the heat source for melting the incineration ash, the volume of combustible waste is reduced, and the solidified pulverized solid fuel is used. The incineration ash can be melted within 6. The incinerated ash that has been melted and slagified in this way is reduced in volume and rendered harmless,
It can be disposed of as it is at the final disposal site.

[0019]

As described above, according to the present invention, incineration ash generated by incineration of combustible waste is slagged and reduced in volume, and it is rendered harmless, and secondary pollution due to disposal and lack of disposal site. Etc. can be resolved. Moreover, since the fuel for melting the incinerated ash uses a solid fuel obtained by reducing the volume of the combustible dust and solidifying it, it is possible to incinerate the combustible dust at the same time as melting the incinerated ash. . Therefore, it does not require a separate energy source other than general waste,
In addition to saving energy, no extra combustion is required other than incineration of waste, and the generation of carbon dioxide can be minimized. That is, it is possible to effectively use the energy of the combustible waste and efficiently process the incineration ash generated by the incineration.

[Brief description of drawings]

FIG. 1 is a flow sheet showing a waste treatment system including a waste treatment method according to an embodiment of the present invention.

FIG. 2 is a plan view showing an example of a melting furnace for carrying out the waste treatment method according to the embodiment.

3 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 Furnace wall 2 Fuel injection port 3 Combustion ash input port 4 Molten ash discharge port 5 Exhaust gas outlet 6 Combustion melting chamber

Claims (2)

[Claims] 1. A method of treating waste, which is produced by reducing the volume of combustible waste and solidifying it into solid fuel, crushing this solid fuel, and incinerating combustible waste discarded as waste. Incinerator ash as a residue is melted in a melting furnace using the pulverized solid fuel as a heating fuel source to form slag. 2. A waste treatment method, wherein the melting furnace is a swirling melting furnace in which pulverized solid fuel is blown into the furnace chamber to burn and melt while swirling the fuel and the melt in the furnace chamber.