JPH05104073A - Method for thermally decomposing dioxin in ash discharged from waste refuse incinerator - Google Patents

Abstract

PURPOSE:To make dioxin harmless in low cost by guiding the ash discharged from a waste refuse incinerator to an ash storage hopper without bringing the same into contact with air and winding an electric heater around the ash storage hopper to heat said ash. CONSTITUTION:The main ash from a waste refuse incinerator 1 is guided to an ash storage hopper 10 in such a state that it is not brought into contact with air without being cooled and the fly ash recovered by a dust collector 3 is also guided to the ash storage hopper 10 without being brought into contact with air. An electric heater 11 is wound around the ash storage hopper 10 and a double flap damper 12 is provided to the lower part of the ash storage hopper 10, and a heating time can be adjusted according to the opening and closing time of the damper 12. The ash stored in the ash storage tank 10 is heated in a low oxygen atmosphere at required temp. for a required time by putting the heat possessed by the main ash and dioxin is thermally decomposed to be made harmless. The harmless ash is fed out by a conveyor 13 by opening the damper 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for thermally decomposing dioxin contained in ash discharged from a refuse incinerator.

[0002]

2. Description of the Related Art The treatment of harmful substances such as dioxins in the ash discharged from refuse incinerators has been highlighted as a social problem. Considering that it is not a substance that does, it is not a drastic solution. Therefore, it is necessary to decompose harmful substances such as dioxins in ash to make them harmless.

Conventionally, as a method of decomposing dioxin in ash, for example, JP-A-2-78479 has been proposed. In this method, a heater is wound around a conveyor to heat ash for dechlorination.

[0004]

The object of the invention is to be Solved by the way, decomposition of dioxin, in the O ₂ presence, 700~800 ℃, O ₂
A temperature of about 550 ° C. is necessary in an atmosphere in which there is no.

In this case, as described above, in the method of heating the ash by winding the heater on the conveyor, the ash must be heated to a high temperature, and the heating efficiency is poor.
There is a problem that operating costs such as electricity bills increase. An object of the present invention is to provide a method capable of performing the above-mentioned thermal decomposition of dioxin at low cost.

[0006]

A method for thermally decomposing dioxin in ash discharged from a waste incinerator of the present invention is to guide ash discharged from a waste incinerator to an ash storage hopper without contacting air, An electric heater is wound around the ash storage hopper for heating.

[0007]

[Function] The temperature required for decomposing dioxin can be lowered by guiding and heating the ash in the ash storage hopper without contacting the air. Further, by heating the ash by winding an electric heater around the ash storage hopper, it is possible to perform heating with high thermal efficiency. In this way, the thermal decomposition of dioxin can be performed at low cost.

[0008]

FIG. 1 shows an example of the equipment configuration for carrying out the method of the present invention.

Exhaust gas from the refuse incinerator 1 reaches the dust collector 3 after heat is recovered by, for example, the waste heat recovery boiler 2, where fly ash is recovered and removed, and the cleaned exhaust gas is the induced blower 4. Are sucked into the atmosphere and discharged from the chimney 5 into the atmosphere.

Then, the main ash from the incinerator 1 is not cooled in a state where it does not come into contact with air, and the ash storage hopper 1
Lead to zero. Fly ash collected by the dust collector 3 is also guided to the ash storage hopper 10 in a state where it does not come into contact with air.

An electric heater 11 is wound around the ash storage hopper 10. A double flap damper 12 is provided below the ash storage hopper 10. The heating time can be adjusted by the opening / closing time of the double flap damper 12.

Then, by utilizing the heat of the main ash, the ash stored in the ash storage hopper 10 is heated to a required temperature, for example, 500 ° C. or higher for a required time in a low oxygen atmosphere to thermally decompose dioxin. To make it harmless. In this way, the detoxified ash is carried out by the conveyor 13 after opening the damper 12. In addition, as shown in FIG.
If the stirrer 12 is provided and the stored ash is stirred, the ash can be efficiently heated.

[0013]

The method for thermally decomposing dioxin in ash discharged from the refuse incinerator of the present invention is as described above. By thermally decomposing dioxin in ash in a low oxygen atmosphere, dioxin can be produced at low cost. Can be rendered harmless.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of an equipment configuration for carrying out the method of the present invention.

FIG. 2 is an explanatory diagram in which an agitator is provided in the ash storage hopper.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tsuyoshi Nakao Marunouchi 1-2-2 Nihon Kokan Co., Ltd. (72) Inventor Kentaro Ito 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Main Steel Pipe Co., Ltd.

Claims (1)

[Claims] 1. An ash discharged from a refuse incinerator is guided to an ash storage hopper without being in contact with air, and an ash heater is wound around the ash storage hopper to heat the ash, and the ash is discharged from the waste incinerator. Thermal decomposition method of dioxin in ash.