JP2002115832A - Waste melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste melting furnace, in which channeling of gas ascending in the furnace is prevented, dust-removing efficiency is improved, and dust- making is reduced. SOLUTION: Waste is charged from the furnace top, and air or oxygen- enriched air is blown from a tuyere provided in the lower part of the furnace, to subject the waste to reduction-combustion, and to be gasified. The combustion residue is melt-treated. A hollow-forming member 5 for making a hollow 6 for drawing a gas from the lower part is provided in the upper center part of the furnace, in connection to an exhaust gas duct.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste melting furnace for melting and processing municipal solid waste, industrial waste, sludge, waste obtained by excavating waste landfilled at a final disposal site, and the like.

[0002]

2. Description of the Related Art Wastes include general waste mainly composed of municipal waste, various kinds of industrial waste, incinerated ash, landfill waste containing sediment reclaimed after being once landfilled, and sludge. As a waste disposal method, there is known a waste melting and disposal method in which waste is dried, preheated, pyrolyzed, burned, and melted in a waste melting furnace, and combustion residues are removed as slag or metal.

FIG. 4 is a longitudinal sectional view schematically showing a conventional waste melting furnace.
The waste is charged from the waste charging chute 2b of the waste charging device 2 having the seal valve 2a, and limestone or coke is charged as an auxiliary material. Air or oxygen-enriched air containing a mixture of oxygen and air is blown from the tuyere 3 at the bottom of the furnace to burn coke and carbonaceous materials generated by thermal decomposition at high temperature in a high-temperature hearth, and to reduce and burn waste. On the other hand, the combustion residue is melted and turned into slag, and the gas rising in the furnace is discharged from an exhaust gas duct 4 and processed in an exhaust gas treatment system.

[0004]

In a conventional waste melting furnace, air is blown from the lower part of the furnace as an oxygen source, and the generated gas is uniformly raised in the refuse in the furnace. The structure is designed to capture and collect dust and dirt.

However, since the waste melting furnace processes various kinds of waste, a gap is easily formed between the waste and the inner wall surface. In this case, the high-temperature gas that rises in the furnace is in a state where it easily flows, and when the high-temperature gas flows through the gap, the dust is heated and shrinks to form a cavity, and the high-temperature gas easily flows and the cavity moves upward. When it expands and a chimney-like cavity is generated, the high-temperature gas directly reaches the furnace upper part, and a gas containing a large amount of ash is discharged from the waste melting furnace as exhaust gas.

[0006] As described above, in the conventional waste melting furnace, when the gas rises unevenly along the furnace wall, the gas is spouted locally on the waste surface portion at the upper part in the furnace, so that the ash soot is generated. Are transported to the exhaust gas duct as it is, and it has a structure that generates a lot of dust.

Accordingly, the present invention is to provide a waste melting furnace which prevents the gas drifting in the waste melting furnace from rising in the dust melting furnace and raises the dust removal efficiency and generates less dust.

[0008]

SUMMARY OF THE INVENTION The waste melting of the present invention comprises:
Waste is charged from the top of the furnace, air or oxygen-enriched air is blown from the tuyere at the bottom of the furnace, the waste is reduced and burned to gasify, and the combustion residue is melt-processed in a waste melting furnace. A cavity forming member having a shape in which a cavity for sucking gas from below is formed is disposed at the center of the upper part of the waste melting furnace, and the cavity forming member is connected to an exhaust gas duct.

The cavity forming member may have a mountain-shaped cross section in which a cavity is formed below, and may have a structure in which a gas suction port is formed below.

[0010]

1 is a longitudinal sectional view schematically showing an embodiment of the present invention, FIG. 2 is a side sectional view, and FIG. 3 is a sectional view taken along line AA of FIG.

The same components as those of the conventional waste melting furnace shown in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.

In the waste melting furnace of the present invention, as in the conventional waste melting furnace shown in FIG. 4, waste is charged from the furnace top, and air or oxygen-enriched air is discharged from the tuyere at the bottom of the furnace. The waste is blown, the waste is reduced and gasified by combustion, and the combustion residue is melted.

At the center of the upper part of the waste melting furnace, a cavity forming member 5 is disposed across the furnace body. Cavity forming member 5
Has a shape in which the lower part is opened and the cavity 6 is formed. The upper surface of the cavity forming member 5 is formed with a downwardly inclined surface on both sides so that the waste can easily descend. For example, the upper surface of the cavity forming member 5 may have a shape in which a cavity is formed below and the cross section has an inclined surface such as a mountain shape. preferable. Below the cavity forming member 5, a gas suction port 7 for sucking gas rising in the furnace is formed. Both ends of the cavity forming member 5 are connected to an exhaust gas duct 8 outside the furnace.
Connected to.

In the present invention, since the gas rising in the furnace is sucked by the cavity forming member 5, a waste charging chute 2b provided with a seal valve 2a is disposed in the upper part of the waste melting furnace, and a ceiling at the furnace top is provided. 9 is closed.

In the above configuration, the high-temperature gas rising from the lower part of the waste melting furnace is supplied to the cavity forming member 5 at the center of the furnace.
Is collected in the gas inlet 7 of the air and sucked into the cavity 6,
It is discharged from the exhaust gas duct 8. As a result, it is possible to prevent local drift that is ejected to the upper surface of the waste through the furnace wall, and because the gas is forcibly passed through the waste layer and collected in the cavity 6, the dust in the gas is removed from the waste. Then, the dust is sucked after being removed by the dust, so that the amount of dust transported outside the furnace can be reduced. In addition, waste input chute 2
Since the fresh waste introduced from above and the gas collected in the cavity forming member 5 intersect at the lower portion of the cavity forming member 5, the thermal efficiency is improved.

[0016]

According to the waste melting furnace of the present invention, dust in gas is collected in the waste, so that the dust collection rate is improved and the melting slag conversion rate in the furnace is improved. In addition, since the fresh garbage and the gas intersect, the thermal efficiency is improved.

Also, since local drift of gas can be prevented, blow-through can be prevented. Therefore, a stirrer or the like in the furnace for removing a non-uniform flow as in the prior art is not required, and the upper part of the furnace is not impeded. Because high temperature gas does not go due to uniform flow,
The heat-resistant structure at the upper part of the furnace can be simplified, and the construction cost can be reduced by using low-grade materials.

Further, since dust collected in the furnace and discharged to the outside of the furnace can be reduced, the dust load in the post-process can be reduced, the wear due to dust, the life can be increased, and the size of the dust discharging equipment can be reduced. The cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing an embodiment of the present invention.

FIG. 2 is a side sectional view of the embodiment shown in FIG. 1;

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a longitudinal sectional view schematically showing a conventional waste melting furnace.

[Explanation of symbols]

 1: Shaft section 2: Waste charging device 2a: Seal valve 2b: Waste charging chute 3: Tuyere 4: Exhaust gas duct 5: Cavity forming member 6: Cavity 7: Gas suction port 8: Exhaust gas duct 9: Furnace top Ceiling

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F23G 5/24 ZAB B09B 3/00 ZAB F27B 1/08 303K F term (reference) 3K061 AA16 AB02 AB03 AC01 AC02 CA08 DA17 DB02 DB14 DB16 DB20 3K065 AA16 AB02 AB03 AC01 AC02 FA09 4D004 AA46 CA27 CA29 CB04 CB31 CC01 CC02 4D059 AA03 BB03 BB04 BB11 4K045 AA01 BA10 CA02 GA15 GB10

Claims (2)

[Claims] 1. Waste is charged from the top of the furnace, air or oxygen-enriched air is blown from a tuyere at the bottom of the furnace, the waste is reduced and burned to gasify, and the combustion residue is melted for disposal. In the material melting furnace, a cavity forming member having a shape in which a cavity for sucking gas is formed from below is disposed at the center of the upper part of the waste melting furnace, and the cavity forming member is connected to an exhaust gas duct. And waste melting furnace. 2. The waste melting furnace according to claim 1, wherein the cavity forming member has a mountain-shaped cross section in which a cavity is formed below, and a gas suction port is formed below.