JPH11351534A - Waste melting furnace and its refractory material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the erosion of a refractory material and the iron plate of a water-cooled jacket covering the refractory material by preventing the permeation of a corrosive gas into the refractory material by applying a fire- resistant powder to at least either one of the front and rear surfaces of the refractory material in a waste melting furnace having a furnace casing made of the refractory material. SOLUTION: A waste melting furnace 1 is provided with a bottomed cylindrical furnace casing 2 having a slag hole for extracting molten slag 3 and a flue gas on its lower side face. In addition, a graphite electrode 5 and an electrode 6 both of which are connected to a DC power unit 4 are respectively provided in the upper and lower sections of the casing 2 and the incineration ash of wastes are heated and melted with high-temperature plasma 7. The casing 2 is formed of a refractory material 2a, such as refractory bricks, etc., and, at the same time, a heat-resistant powder 8 composed of an aluminum oxide powder, etc., is applied to the surface of the material 2a. The particle size of the powder 8 is set at 0.1 μm or below. On the other hand, a water- cooled jacket 9 composed of an iron plate 92 is provided on the external surface of the material 2a and cooling water W is contained in the jacket 9.

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 incinerated ash such as sewage sludge, municipal solid waste and industrial waste, and incinerated ash discharged from a combustion furnace of a commercial thermal power plant and the like, and a refractory furnace therefor. It is about materials.

[0002]

2. Description of the Related Art Conventionally, incinerated ash (powder inorganic matter) such as sewage sludge, municipal solid waste, and industrial waste has been used, for example, as shown in FIG. The waste is melted by a waste melting furnace 51 and taken out as slag. That is, in order to melt the incinerated ash in the furnace main body 52 using such a melting furnace 51, the incinerated ash discharged from the refuse incinerator 53 is screened by the dry ash removal device 54, the ash conveyor 56, the ash The incinerated ash is charged into the furnace main body 52 through the supply conveyor 57 and the fixed-quantity charging device 58, and the charged incineration ash is melted by the high-temperature plasma 59. The molten slag 60 is discharged from a slag port 61 through a slag gutter 62 to a dry slag apparatus 63, guided to a slag pit 65 via a slag conveyor 64, and used for various uses. For this reason, a graphite electrode 67 and an electrode 68 connected to a DC power supply device 66 are provided at the upper and lower portions of the furnace main body 52, and nitrogen gas is supplied to the graphite electrode 67 from a nitrogen gas generator 69. It has become. The refuse incinerator 53 is communicated with a chimney 71 via a bag filter 70, and the exhaust gas generated in the furnace body 52 passes through a CO combustion chamber 72, a cooling tower 73, a bag filter 74 and an exhaust gas fan 75, and the incinerator smoke is discharged. I am being led on the road. Then, air is supplied to the CO combustion chamber 72 from a combustion air fan 76 and the bag filter 7
4 is connected to the molten fly ash treatment device 77.

The furnace body 52 of the waste melting furnace 51
As shown in FIG. 3, is formed of a refractory material 52a, and the outer surface of the refractory material 52a is covered with a water-cooling jacket 78 containing cooling water W therein. For this reason, the water cooling jacket 78 is formed in a closed cross-sectional shape using the iron plate 78a.

[0004]

However, in the above-mentioned conventional waste melting furnace 51, the corrosive gas generated in the furnace main body 52 passes through the refractory material 52a and passes through the water-cooled jacket 7.
8 penetrates to the iron plate (iron skin) 78a.
a may be corroded. Further, when the corrosive gas permeates into the refractory material 52a of the furnace main body 52, the refractory material 52a is eroded, so that there is a problem in the long-term durability of the melting furnace 51. Moreover, the refractory material 52a
There was a problem that the insulation performance of the refractory material 52a was lowered due to gas permeation into the refractory material 52a.

The present invention has been made in view of such circumstances, and has as its object to prevent erosion of a refractory material constituting a furnace body and corrosion of an iron plate constituting a water cooling jacket. It is to provide a possible waste melting furnace and its refractory material.

[0006]

According to the present invention, in a waste melting furnace in which a furnace body is made of a refractory material, at least one of a front surface and a back surface of the refractory material is provided. Heat-resistant powder is applied to one surface. Further, the present invention is a refractory material for a waste melting furnace obtained by applying a heat-resistant powder to at least one of the front surface and the back surface.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments.

FIG. 1 is a sectional view conceptually showing a waste melting furnace according to an embodiment of the present invention. As shown in FIG. 1, a waste melting furnace 1 of the present embodiment has a furnace body 2 formed in a cylindrical shape with a bottom, and a lower side surface of the furnace body 2
A slag port (not shown) for extracting the molten slag 3 and the exhaust gas is provided. In addition, graphite electrodes 5 and electrodes 6 connected to the DC power supply 4
Is arranged, and the graphite electrode 5 is configured to be supplied with nitrogen gas from a nitrogen gas generator (not shown).
The input waste incineration ash is heated and melted by the high-temperature plasma 7.

The furnace body 2 is made of a refractory material (brick, caster) 2a. Moreover, the refractory material 2a
Aluminum oxide (Al)
₂ O ₃ ), boron nitride (BN), magnesium oxide (M
gO) is applied, and a coating layer is formed by this. The particle size of the heat-resistant powder 8 is 0.1 μm or less. If the heat-resistant powder 8 having a particle size larger than this value is used, it is difficult to close the pores in the refractory material 2a, which is not preferable.
In the present embodiment, aluminum oxide powder is used as the heat-resistant powder 8, but a powder containing a large amount of boron nitride (BN) or the like may be used as long as it has heat resistance.

On the other hand, a water cooling jacket 9 having a closed cross section is provided on the outer surface of the refractory material 2a, and the water cooling jacket 9 is formed using an iron plate 9a. Cooling water W for cooling the furnace main body 2 is stored inside the water cooling jacket 9, and the water cooling jacket 9 is connected to a water supply source (not shown) so that the cooling water W circulates therein. Has become.

In such a waste melting furnace 1, when the incinerated ash of the waste is supplied into the furnace main body 2, the supplied incinerated ash is heated and melted by the high-temperature plasma 7, and the slag 3
Becomes The molten slag 3 is discharged from a slag port (not shown) through a slag gutter and dropped into a mold (not shown) to be collected. On the other hand, the exhaust gas generated in the furnace body 2 is extracted from a slag port (not shown), and is guided to an exhaust gas treatment facility via an exhaust gas duct (not shown).

In the waste melting furnace 1 according to the present embodiment,
Since the refractory powder 8 is applied to the front and back surfaces of the refractory material 2a constituting the furnace body 2, the refractory powder 8 is applied to the refractory material 2a.
By filling the pores in a, the passage of the corrosive gas generated in the furnace main body 2 can be eliminated. Therefore, the corrosive gas does not penetrate into the iron plate 9a of the water cooling jacket 9 and the refractory material 2a of the furnace body 2, and the corrosive gas corrodes the iron plate 9a or erodes the refractory material 2a. Can be prevented.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes may be made without departing from the gist of the present invention. What you get. For example, in the present embodiment, the heat-resistant powder 8 is applied to the front and back surfaces of the refractory material 2a, but the heat-resistant powder 8 is applied to only one of the front surface and the back surface by a melting furnace to be applied. Is also good.
The present invention can be applied not only to a plasma melting furnace but also to a burner melting furnace and the like.

[0014]

As described above, in the waste melting furnace according to the present invention, since the heat-resistant powder is applied to at least one of the front and back surfaces of the refractory material constituting the furnace main body, The generated corrosive gas will not penetrate into the refractory material, preventing the erosion of the refractory material and preventing corrosion of the iron plate of the water-cooled jacket covering the refractory material, aiming to improve long-term durability be able to. Further, since the refractory material for a waste melting furnace according to the present invention is formed by applying a heat-resistant powder to at least one of the front surface and the back surface, erosion by corrosive gas generated in the furnace body can be prevented, and the Performance can be improved. Therefore, the use of the refractory material of the present invention enables a long-term stable operation of the waste melting furnace.

[Brief description of the drawings]

FIG. 1 is a sectional view conceptually showing a waste melting furnace according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing equipment to which a conventional waste melting furnace is applied.

FIG. 3 is a sectional view conceptually showing a conventional waste melting furnace.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Waste melting furnace 2 Furnace main body 2a Refractory material 3 Melting slag 4 DC power supply 5, 6 Electrode 7 High temperature plasma 8 Heat resistant powder 9 Water cooling jacket 9a Iron plate

Claims (3)

[Claims] 1. A waste melting furnace in which a furnace body is made of a refractory material, wherein a heat-resistant powder is applied to at least one of a front surface and a back surface of the refractory material. 2. A refractory material for a waste melting furnace, wherein a heat-resistant powder is applied to at least one of a front surface and a rear surface. 3. The refractory material for a waste melting furnace according to claim 2, wherein the heat-resistant powder has a particle size of 0.1 μm or less.