JPH0774690B2 - Method and apparatus for melting incinerated ash - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for melting incinerated ash of municipal waste, and more particularly, to incinerate the incinerated ash of municipal waste using a plasma furnace to form slag. The present invention relates to a method for melting incineration ash and a device for reducing the volume of the discharged ash.

[Prior Art] Municipal waste was conventionally disposed of by landfill. However, in recent years it has become extremely difficult to secure land for landfill, and as a countermeasure against that, a method has been adopted in which municipal waste is incinerated in an incinerator and then incinerated ash is further landfilled.

However, even after incineration of garbage, about 10% of the amount of incinerated ash is generated, and it has become difficult to secure a site for landfill disposal of ash. When landfilling the ash, the ash is in the form of fine powder and is prone to scattering, or there is the problem that the heavy metals contained in the ash are leached out, and the generation of a bad odor due to the combustion products when incinerated, There were other environmental problems.

Therefore, the incinerated ash of garbage is further melted to form slag, which is reused in the landfill to reduce the volume and prevent the scattering of fine powder ash and the leaching of heavy metals, or the decomposition of unburned materials. Melting equipment has been developed that can achieve environmental protection all at once. As an incinerator ash melting apparatus for such municipal waste, a technique using an arc furnace or a plasma furnace has been developed (Japanese Patent Application Nos. 63-101360 and 63-27).
3193 etc.).

In some cases, metal pieces are mixed in the incineration ash that is incinerated by such a plasma incinerator. Any metal fragments in the incineration ash must be removed prior to charging the melting ash. The reason is that the volume of the molten material in the melting device is limited, so when the metal melts and accumulates at the furnace bottom of the melting device, the amount of molten slag that accumulates decreases significantly and the processing capacity of the melting device decreases. Because. For this reason, the metal pieces had to be removed before charging the incineration ash into the melting device.

However, it is technically very difficult to separate metal pieces from such incinerated ash, and there is also a cost problem because the number of processing steps increases by one, and in practice complete separation is extremely difficult. was difficult. For this reason, a metal piece enters the incineration ash melting device and the volume of the ash pool of the melting device becomes small,
There was a problem that long-term continuous operation was hindered.

[Problems to be Solved by the Invention] An object of the present invention is to prevent long-term continuous operation without melting metal pieces mixed in the incineration ash in advance when melting the incineration ash of municipal waste using plasma. It is an object of the present invention to provide a method for melting incinerated ash and a device therefor that does not exist.

[Means for Solving the Problems]

The present invention is applied to a method for melting incineration ash by incinerating municipal waste mixed with metal pieces and melting this incineration ash, using a plasma torch in the melting furnace and melting without stopping the plasma arc. It is a method for melting incineration ash, which is characterized in that the furnace main body is tilted to operate while discharging molten metal accumulated in a melt pool.

INDUSTRIAL APPLICABILITY The present invention is applied to an incinerator ash melting apparatus that incinerates municipal waste mixed with metal pieces and melts the incinerated ash, and uses a plasma torch in the melting furnace of the melting apparatus to tilt the melting furnace body. Melt of incineration ash, which is supported rotatably and is provided with a discharge hole for discharging molten metal accumulated in the furnace bottom at a position higher than the discharge hole, and a sliding gate that can be opened and closed is provided in the discharge hole. It is a device.

[Action]

According to the present invention, a plasma torch is used in the melting furnace, and the melting furnace main body can be tilted without stopping the plasma arc to operate while discharging the molten metal accumulated in the molten material pool. Therefore, it is not necessary to treat the metal pieces mixed in the incinerated ash in advance, and since the plasma arc is not stopped, it is possible to discharge the molten metal while maintaining the temperature inside the furnace. The temperature change can be controlled to be small, and damage to the refractory such as cracks can be prevented. Therefore, the processing cost of the metal pieces can be reduced, and the furnace can be operated for a long time without being shut down and the life of the furnace can be extended.

〔Example〕

FIG. 1 is a longitudinal sectional view of an embodiment of an apparatus 1 for melting incinerated ash, which can preferably carry out the method of the present invention. The melting apparatus 1 has a molten material pool 3 for storing molten material, that is, molten slag 4 and molten metal 5 in a furnace bottom 2. The continuous slag hole 6 is provided so that the molten slag 4 overflows from the upper end of the molten material pool 3. Is equipped with.

Further, the melting device 1 is provided with a plasma torch 7, and melts incineration ash continuously supplied by an incineration ash supply device (not shown) with plasma 8.

The molten slag 4 that overflows and is discharged from the slag hole 6 is water-atomized by the high-pressure water sprayed from the spray water nozzle 21, flows down the trough 22, and collects in the water tank 23. Unloading device
24 scrapes this up and collects the granulated slag 26 in the container 25.

A discharge hole 9 for discharging the molten metal 5 is provided at a position higher than the continuous slag hole 6. This discharge hole 9 is a sliding gate 10
Normally closed by. FIG. 2 shows a state in which the molten metal 5 is accumulated in the molten material pool 3 and thus the melting apparatus 1 is tilted to discharge the molten metal 5 from the molten metal discharge hole 9. When the melting device 1 is tilted and the sliding gate 10 is opened, the molten metal 5 is discharged from the melting device 1 by gravity.

When the molten metal 5 is completely discharged and then the molten slag starts to be discharged, the sliding gate 10 is immediately closed. Next, the melting apparatus 1 is tilted in the opposite direction and returned to the original fixed position shown in FIG. During this time, the plasma arc was not stopped.

It is possible to continue the melting operation during the above work.
Therefore, according to the present invention, the incineration ash charged into the melting device is melted as it is without excluding the metal pieces in advance, and when the molten metal 5 is accumulated in the furnace, the melting device 1 is tilted and melted. Since it is sufficient to discharge the metal 5 and continue the operation, it is possible to continuously and stably operate the melting apparatus.

[Advantages of the Invention] According to the present invention, there is no need to pre-treat metal pieces mixed in incinerated ash. Further, since the molten metal can be discharged from the molten metal discharge hole at any time to continue the operation without stopping the plasma arc, the incineration ash melting apparatus can be continuously operated for a long period of time.

Further, the life of the furnace refractory can be extended, the repair cost can be reduced, and the improvement of the operation rate of the furnace can be expected. Therefore, it is possible to significantly reduce the cost of operation.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an incinerator ash melting apparatus according to an embodiment in which the method of the present invention can be suitably implemented, and FIG. 2 is a vertical cross-sectional view showing a state in which the melting apparatus is tilted. 1 ... Melting device, 2 ... Furnace bottom 3 ... Molten material pool, 4 ... Molten slag, 5 ... Molten metal, 6 ... Slag hole, 7 ... Plasma torch, 8 ... Plasma, 9 ... Discharge hole , 10 …… sliding gate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiko Nakagawa 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki Steel Co., Ltd. Tokyo headquarters (72) Inventor Taketoshi Yamazaki 1-1-1, Uchisaiwaicho, Chiyoda-ku, Tokyo No. 3 in Tokyo Electric Power Company (56) Reference JP-A-55-131614 (JP, A) JP-A-64-10016 (JP, A) JP-B-62-24694 (JP, B2)

Claims (2)

[Claims] 1. A method for melting incineration ash, comprising incinerating municipal waste mixed with metal pieces and melting the incineration ash, wherein a plasma torch is used in the melting furnace, and the melting furnace main body is tilted without stopping the plasma arc. A method for melting incinerated ash, which comprises operating while discharging molten metal accumulated in a melt pool. 2. An incinerator ash melting apparatus for incinerating city refuse mixed with metal pieces and melting the incinerated ash, wherein a plasma torch is used in a melting furnace of the melting apparatus, and the melting furnace main body is tiltably supported. A melting device for incinerator ash, characterized in that a discharge hole for discharging molten metal accumulated on the furnace bottom is provided at a position higher than the slag hole, and a sliding gate that can be opened and closed is provided in the discharge hole.