JPH06347014A - Melting furnace for incineration ash and method for blowing air into it - Google Patents

Abstract

PURPOSE:To burn combustible gases completely with the least amount of air necessary by providing in the circumferential wall of a furnace body a plurality of nozzles scatteringly and in a manner of directing the blow from each nozzle with a deviation uniformly to one side from the radial direction of the furnace body so as to produce a swirl inside the furnace body by the blow from the nozzles. CONSTITUTION:A hollow furnace body 2 having inside a depositing space 6 for incineration ash 34 to be melted is provided with an electrode 27 for melting the incineration ash 34 in the depositing space 6, nozzles 16 by which air for burning combustible gases produced from unburnt combustibles in the incineration ash 34 in the depositing space 6 is blown into the furnace body 2, and a gas-discharging hole for discharging gases from inside the furnace body 2. A plurality of nozzles 16 are provided in the circumferential wall 5 of the furnace body 2 scatteringly and in a manner of directing the blow from each nozzle 16 with a deviation uniformly to one side form the radial direction of the furnace body 2 so as to produce a swirl inside the furnace body 2 by the blow from the nozzles 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incinerator ash melting furnace used for melting municipal waste and various other incinerator ash for the purpose of stabilizing and reducing the volume thereof, and a method for blowing air into the incinerator ash melting furnace.

[0002]

2. Description of the Related Art A hollow furnace body having a space for storing incineration ash for melting inside has an electrode for melting the incineration ash in the space for retaining and an incinerator placed in the space for retaining. It is equipped with a nozzle for blowing air into the furnace for burning combustible gas generated from unburned components in ash, and a gas outlet for discharging the gas in the furnace (for example, Japanese Patent Publication No.
0-56963).

In such an incinerator ash melting furnace, when incinerator ash is melted, when a combustible gas is generated from unburned components in the incinerator ash, the gas enters the furnace through the air port and is discharged to the gas discharge port. Combustion can be performed by making contact with air that travels straight ahead, and the risk of explosion or the like can be prevented in advance.

[0004]

However, in the above case, since the air flow in the furnace is straight, there are many places outside the passage area in the furnace, and the flammable gas generated at the outside is inconsistent. Complete combustion causes a large amount of CO gas, which is a safety problem. In addition, if a large amount of the air is put into the furnace, it is possible to ensure the completeness of combustion of the combustible gas, but in that case, the air takes a large amount of heat from the inside of the furnace and is discharged to the outside of the furnace. Therefore, a large amount of electric power to be input is required, which causes a problem that operating costs increase.

The present invention has been made in order to solve the above-mentioned problems (technical problems) of the prior art, and it is necessary to increase the chances that flammable gas generated in the furnace will come into contact with air. It is an object of the present invention to provide an incinerator ash melting furnace capable of completely burning the combustible gas with a minimum amount of air, and an air blowing method in the incinerator ash melting furnace.

[0006]

In order to achieve the above object, the incinerator ash melting furnace of the present invention has a hollow furnace body having a space for storing the incinerated ash for melting inside, and An electrode for melting the incineration ash of the space, a nozzle for blowing air into the furnace body to burn the combustible gas generated from the unburned components in the incineration ash placed in the space for storage,
In an incinerator ash melting furnace having a gas outlet for discharging gas in the furnace body, the nozzles are scattered on the peripheral wall of the furnace body, and the blowing direction of those nozzles is from the nozzles. In order to generate a swirl flow in the furnace body by the blown air, the directions are biased to the same side from the direction toward the center of the furnace body.
The method of blowing air in the incinerator ash melting furnace of the present invention, the incinerator ash put in the furnace body is melted by the electric power supplied through the electrodes provided in the furnace body,
From a plurality of nozzles scattered around the peripheral wall of the furnace body, blown air in a direction biased to the same side from the direction facing the center of the furnace body to generate a swirling flow, and the swirling flow In the method of blowing air in an incinerator ash melting furnace in which a flammable gas generated from the unburned content of the incinerated ash to be melted is burned by the air, when the amount of the flammable gas is small, the flammable gas The amount of air required for the combustion of the air is blown from a selected small number of the plurality of nozzles so as to generate a swirling flow in the furnace body.

[0007]

The incineration ash is melted in the furnace body by the electric power supplied through the electrodes. The flammable gas generated from the unburned components in the incineration ash at the time of melting contacts with the air blown from a plurality of nozzles and burns. In this case, a swirling flow is formed in the furnace by the blowing output of air from the nozzle. Therefore, the air blown from each nozzle reaches a gas outlet through a large area in the furnace and comes into contact with the combustible gas in the process. Also, the flammable gas generated in a place other than the passage area is swirled by the swirling flow and comes into contact with the air. Therefore, any combustible gas generated in any space is brought into good contact with the air and completely combusted. When the amount of combustible gas generated in the furnace is small,
When air is blown out from a small number of the above nozzles, a small amount of air necessary for burning the combustible gas can be blown out from the nozzles at a high flow rate, and the swirl flow is formed in the furnace body. it can.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. Reference numeral 1 is an incinerator ash melting furnace, 2 is a hollow furnace body in the melting furnace, and a bottom portion 3 having a molten material 31, for example, a base metal 32 and a space 4 for retaining the molten slag 33 thereon, and the above-mentioned molten material 31 A peripheral wall 5 surrounding the space 6 for storing incineration ash for melting on the above, and a ceiling portion (usually referred to as a furnace ceiling) 7 that closes above the space 6 for storing incineration ash. There is. As is well known, the bottom portion 3, the peripheral wall 5, and the ceiling portion 7 are each constructed by lining a steel outer shell with a refractory material. Reference numeral 9 denotes a lower element of the peripheral wall 5, which is integrally formed with the bottom portion 3 and constitutes a portion usually called a furnace bottom 11. A slag opening is provided in a part of the lower element 9.
12 is formed, and the molten slag 33 can be discharged by tilting the furnace bottom 11 in the direction of arrow 13. 10 is the lower element 9 above
It is an upper element that is flange-connected to and is usually called a furnace lid.

Reference numerals 15 to 22 show a well-known structure provided in the upper element 10, 15 is an inlet for incineration ash, 16 is a nozzle for blowing air to burn combustible gas, and 17 is a gas outlet. ,
18 is an inspection port, 19 is a working port, 20 is an explosion safety port, 21 is a temperature measuring port, and 22 is an auxiliary electrode port. The arrangement of the blowing nozzle 16 will be described. The nozzle 16 is an upper element as shown in FIG.
As shown in FIG. 1, a plurality of them are scattered at 10, and each is provided at a height position for preventing blockage due to splash from the melt, for example, at a position 600 mm or more from the metal line 32a. The blowing directions 16a of the respective nozzles 16 are the same from the direction facing the center 5c of the furnace body as shown in FIG. (See the left side as shown)
The orientation is biased toward. For example, when the nozzle 16 is provided, the angle θ is 3 with respect to the tangential direction 10b of the peripheral wall.
It is about 0 to 60 °. Moreover, each of the above nozzles
The blowout direction 16a of 16 is oriented slightly downward from the horizontal as shown in FIG. 1 so that the blown air hits a combustible gas generated as described later. Next, 23 and 24 in FIG. 2 are stirring nozzles,
This is for improving the mixing of the combustible gas and the air between the nozzle 16 and the ceiling portion 7. For example, the distance between the ceiling portion 7 and the metal line 32a is large, and the nozzle 16 and the ceiling portion 7 are
It is provided when there is a possibility that the above-mentioned mixing with and is insufficient. These nozzles 23, 24 are provided in order to increase the stirring action in the space between the nozzle 16 and the ceiling portion 7, for example, as shown by the arrow in FIG. It is better to make a difference from the blowing direction 24a.

Next, reference numerals 26 to 29 show a well-known structure provided in the ceiling portion 7, where 26 is an electrode port, 27 is an electrode, 28 is a melting start material charging port, and 29 is a level meter port.

In the melting furnace 1 having the above-mentioned structure, as is well known, the incineration ash 34 which is charged from the charging port 15 and placed in the space 6
Spreads on the base metal 32 and is heated and melted by the heat of the arc emitted from the electrode 27 when electric power is applied to the electrode 27 to become a molten slag 33.

In the above process, air is blown from each nozzle 16. By heating the incineration ash, combustible gas generated from unburned components generally contained in the incineration ash in an amount of 3 to 5% comes into contact with the air and burns, and combustion exhaust gas is discharged from the gas discharge port 17. In this case, since the air is blown out from each nozzle 16 in the direction of the arrow 16a, the swirling flow in the space 6 in the clockwise direction in FIG. Therefore, the air blown from each nozzle 16 comes into contact with the combustible gas in the process of passing through a wide area in the space 6, and the combustible gas generated in a place other than the passing area is swirled by the swirling flow. As a result, the combustible gas generated in any part of the space 6 can be brought into good contact with the air and completely combusted. Further, in the above case, the air blown from the nozzle 16 is downward from the horizontal, and the air is directly exposed to the combustible gas generated from the incineration ash 34 and rising, so that the combustibility is high. The gas contacts the air for combustion at the place where it is generated, increasing the certainty of combustion. In the above case, the flow velocity of the air blown out from each nozzle 16 is to maintain a good mixed state with the combustible gas due to the generation of the swirling flow,
It is good to set it to 10 to 15 m / sec or more.

When the amount of combustible gas generated in the furnace body 2 is small, the amount of air required for combustion of the combustible gas is reduced to a small number of nozzles selected from the plurality of nozzles 16. It blows out from 16. The amount of air is approximately proportional to the amount of incinerated ash to be processed, and therefore the amount of air is calculated according to the amount of incinerated ash to be processed. The number of nozzles 16 that blows is determined so that the flow velocity of the air blown from each nozzle is such that a swirl flow can be formed by the air in the furnace. In order to form a stable swirl flow, the number of nozzles 16 to be blown out may be equalized in each part of the peripheral wall 5, and for example, every other nozzle 16 or every two nozzles 16 may be used. Blow out.

[0014]

As described above, according to the present invention, when combustible gas generated from unburned components in incinerated ash 34 is burned when the incinerated ash 34 is melted, a plurality of blowing nozzles are used.
Since the combustion air blown from each of the 16 forms a swirl flow as a whole in the furnace, the air blown from any of the nozzles 16 travels over a wide area in the furnace toward the gas outlet 17, and thus the above-mentioned The flammable gas has a feature that it has many opportunities to come into contact with the air and can be burned well.

Moreover, since the swirl flow is formed as described above, the combustible gas itself generated from the unburned components can also be swirled in the furnace, and therefore the combustible gas generated at a place outside the air passage area is generated. The characteristic gas is that it can be brought into contact with the air and is well combusted.

As described above, according to the incinerator ash melting furnace of the present invention, the combustible gas generated from the unburned matter can be brought into good contact with the air, so that the combustible gas is completely combusted with the minimum necessary amount of air. There is an effect that can be made possible.

Further, in the air blowing method of the present invention, even when the amount of incinerated ash is small and the amount of combustible gas is small, in that case, the amount required for combustion of the combustible gas is The air is blown out from a small number of nozzles 16, so that the air can be blown out from the nozzles 16 at a high flow rate, the swirl flow can be formed, and the combustible gas can be completely combusted.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an incineration ash melting furnace.

FIG. 2 is a plan view of an incinerator ash melting furnace.

[Explanation of symbols]

 2 furnace body 5 peripheral wall 16 nozzles

Claims (2)

[Claims] 1. A hollow furnace body having a space for storing incineration ash for melting therein, an electrode for melting the incineration ash in the storage space, and an incinerator placed in the storage space. In an incinerator ash melting furnace comprising a nozzle for blowing air into the furnace body for burning a flammable gas generated from unburned components in ash, and a gas discharge port for discharging gas in the furnace body, A plurality of nozzles are scattered on the peripheral wall of the furnace body, and the blowing direction of these nozzles is from the direction toward the center of the furnace body in order to generate a swirling flow in the furnace body by the air blown from the nozzles. The incinerator ash melting furnace is characterized in that they are oriented in the same direction. 2. The incinerator ash contained in the furnace body is melted by electric power supplied through an electrode provided in the furnace body, and the center of the furnace body is separated from a plurality of nozzles scattered on the peripheral wall of the furnace body. To generate a swirling flow in the furnace body by blowing air in the directions biased to the same side, and in the swirling flow, the combustible gas generated from the unburned components of the incinerated ash melted is In the method of blowing air in an incinerator ash melting furnace that burns with air, when the amount of the combustible gas is small, the amount of air required for burning the combustible gas is selected from among the plurality of nozzles. A method for blowing air in an incinerator ash melting furnace, characterized in that a small number of nozzles are blown out so as to generate a swirling flow in the furnace body.