JP2001012720A - Combustion apparatus of powder melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion apparatus of a powder melting furnace in which temperature only on a tip end portion of a flame of a heating burner without scattering ash on a furnace bed owing to oxygen blown out from an oxygen lance, and processing efficiency of melted ash is high with prolonged durability. SOLUTION: A combustion apparatus of a powder melting furnace includes an oxygen lance at a heating burner 4 and a furnace wall member 3 located in the vicinity of the heating burner for blowing oxygen to a combustion flame 7 of the heating burner 4 to raise flame temperature, whereby oxygen is blown to the combustion flame 7 to raise the flame temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder melting furnace for melting incineration ash and fly ash, which are residues of incineration of waste in an incineration facility, or powder having a small particle size such as sewage sludge and asbestos. The present invention relates to a combustion apparatus for a powder melting furnace for directly melting a body.

[0002]

2. Description of the Related Art In an incineration facility for waste such as municipal waste, incineration ash and fly ash, which are incineration residues, are melted at a high temperature to form glassy slag, thereby reducing the volume and detoxifying the residue. Have been. Further, the molten slag thus obtained is discharged from the slag port to the outside of the furnace, and is effectively used by means such as water granulation. Similarly, melting furnaces for sewage sludge, asbestos, and the like are reduced in volume and made harmless by converting them into slag.

[0003] For simplicity, the following description will focus only on the melting of incineration ash and fly ash.

Various methods are known as a method for heating and melting incinerated ash and fly ash. For example, in a surface melting furnace, molten slag is formed using a heating burner. The heating burner used here heats incinerated ash and fly ash by mixing and combusting a combustible substance such as gaseous fuel, liquid fuel, or solid fuel with air.

[0005] In order to melt incinerated ash and fly ash, it is necessary to set the temperature of the incinerated ash and fly ash above their melting points. The melting point of ash ranges from 1170 ° C to 13 ° C depending on the ash composition.
When the mixing ratio of the ash having a high melting point varied up to 20 ° C., the molten slag sometimes solidified at the slag outlet. In this case, an operation of removing the solidified slag manually or manually is required.

As a means for preventing the solidification of the molten slag, a means for raising the temperature in the furnace to raise the temperature of the molten slag to a normal temperature or higher can be considered. To raise the furnace temperature,
It is necessary to increase the combustion capacity of the heating burner, but as a result, the flow rate of the combustion gas increases, causing a problem that the incineration ash or fly ash to be heated is scattered by the flow rate of the combustion gas. Further, there is a drawback that the furnace wall material is greatly worn due to an increase in the furnace temperature, and the amount of exhaust gas increases with an increase in the capacity of the heating burner.

Conventionally, it has been known to use combustion air enriched in oxygen to increase the flame temperature of a heating burner. However, in the conventional oxygen-enriched combustion, the molten slag temperature can be raised more than in the case of normal air combustion, but the furnace temperature also increases at the same time. Was.

[0008] It is also known to use an oxygen lance that blows oxygen gas onto the combustion flame. For example, 60 m / s or more (preferably 120 m
/ Lance), or an oxygen lance that blows out oxygen in a conical shape at a high speed of at least about 0.1 mm / s, or an oxygen lance that blows out a fan-shaped flat surface with respect to the oxygen introduction pipe axis by an oxygen blowing nozzle.
No. 00109) is known.

In these oxygen lances, oxygen is blown out from the combustion flame of the heating burner blown almost in parallel along the surface of the object to be heated, and raises the temperature of the entire flame on the side of the object to be heated. Used for When oxygen is blown at a high speed with these oxygen lances against the incineration ash blown almost perpendicular to the surface of the heating object and the combustion flame of the heating burner of the fly ash melting furnace, the heating object in the blowing direction Ash and fly ash are scattered, and the ash flows out of the melting furnace with the gas in the furnace.

As an example of a low oxygen blowing speed,
To prevent the glass particles in the glass melting furnace from scattering,
Oxygen lance that blows out at a speed of less than m / s
No. 15823). However, in this case, an oxygen lance is provided between the two oxy-fuel burners installed substantially parallel to the glass bath on the wall surface above the glass bath to be heated. However, this arrangement eliminates the short flame characteristic of the oxy-combustion flame and provides the same long flame shape as the air-combustion flame, and does not raise the flame temperature.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to melt incinerated ash and fly ash without increasing wear of furnace wall materials. An object of the present invention is to provide a combustion device for a powder melting furnace using an ash melting furnace oxygen lance that directly raises the slag temperature to prevent the solidification of the molten slag and prevent the ash that is the object of heating from scattering. .

[0012]

SUMMARY OF THE INVENTION A combustion apparatus of a powder melting furnace according to the present invention is capable of removing powder from a heating burner attached to a wall of a melting furnace for powder such as incinerated ash, fly ash or sewage sludge. A combustion apparatus for a powder melting furnace for blowing a combustion flame downward, wherein an oxygen lance for blowing oxygen to the combustion flame of the heating burner to increase the flame temperature is attached to the furnace wall material. Thus, the above object is achieved.

[0013] In one embodiment, a portion of the oxygen lance blown from the oxygen lance to the combustion flame is a tip of the combustion flame.

[0014] In one embodiment, the flow rate of oxygen blown out of the lance is 60 m / s or less.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

First, the combustion apparatus of the furnace of the present invention will be described in detail with reference to the ash melting furnace shown in FIG.

FIG. 1 shows a vertical section in the longitudinal direction of an ash melting furnace equipped with a combustion device. The cross-sectional shape perpendicular to the longitudinal direction of the ash melting furnace is typically rectangular, and the furnace has a bottom surface 3b, a top surface 3a, and both side surfaces. The width of the bottom of the furnace is typically 120 cm and the height is typically 80 cm.
cm.

The bottom portion 3b of the furnace is usually provided with an angle that is gradually lowered toward the downstream side. A heating burner 4 is provided on the upper surface portion 3a of the furnace wall material 3 formed of a refractory brick or the like.
The combustion flame 7 is vertically attached to the furnace wall material 3 so as to blow downward. At a position close to the heating burner 4, an insertion hole 14 for inserting an oxygen lance 13 is formed obliquely with respect to the furnace wall material 3 on the upstream side of the upper surface portion 3 a of the furnace wall material 3. An oxygen lance 13 is inserted through the insertion hole 14, and is fixed to the upper surface 3 a by a mounting boss 16 and a nut 17. Therefore, the tube axis of the oxygen lance 13 and the tube axis of the heating burner 4 intersect at an angle. In the figure, reference numeral 6 denotes a combustion air introduction pipe, and the air from the combustion air introduction pipe 6 and the combustible substance from the combustible substance introduction pipe 5 are mixed and supplied from the heating burner 4 into the furnace. Is configured.

The oxygen lance 13 has an oxygen introducing pipe 8 and an oxygen blowing nozzle section 9 provided at the tip of the oxygen introducing pipe 8. The oxygen blowing nozzle 9 may be formed integrally with the tip of the oxygen introduction pipe 8 or may be formed by fixing another member to the tip of the oxygen introduction pipe 8.

The direction in which oxygen is blown from the oxygen blow-out nozzle 9 is the same as the direction of the tube axis of the oxygen introduction tube 8. The oxygen lance 13 is provided at a portion where the oxygen blown from the nozzle portion 9 wants to raise the temperature of the combustion flame 7 most (FIG. 1).
Then, the center of the combustion flame is set as the origin 15 and the heating burner 4 is located at the part III when divided by the horizontal axis and the vertical axis.
Is attached to the furnace wall 3 so as to be blown out at a flow rate corresponding to the combustion capacity of the furnace. Next, the operation when the combustion apparatus of the present invention is used for a furnace for melting incineration residue ash will be described in detail. The incineration ash and fly ash, which are incineration residues of waste such as municipal garbage, move sequentially toward the slag outlet by the action of the input means, the moving means and the inclination of the bottom of the furnace installed on the upstream side of the furnace. .

When the ash 1 reaches a position below the heating burner 4, a combustion flame blown out from the heating burner 4 having an appropriate combustion capacity constituted by a combustible substance (fuel) introduction pipe 5 and a combustion air introduction pipe 6. At 7, the ash 1 is heated and melted to become molten slag 2, which is discharged from the slag port 11 to the outside of the furnace. The combustible material (fuel) can be a solid, liquid or gaseous fuel.

The oxygen blown from the nozzle portion 9 of the oxygen lance 13 is blown out to the portion of the combustion flame 7 where the temperature is to be raised most at a flow rate corresponding to the combustion capacity of the heating burner 4. As a result, it is possible to increase only the flame temperature of the portion near the ash 1 without increasing the temperature of the entire furnace.

Therefore, the temperature of the molten slag can be increased without increasing the wear of the furnace wall material 3. But,
Oxygen blown out from the conventional oxygen lance at a high speed directly hits the ash in the blowing direction, so that scattering of the ash was observed. By appropriately suppressing the oxygen blowing speed from the oxygen blowing nozzle, scattering of the ash 1 on the hearth can be suppressed.
The blowing speed of oxygen is desirably 60 m / s or less.

[0024]

(Embodiment 1) As shown in FIG.
Using a combustion device using the above-mentioned method, the oxygen blowing velocity at the outlet of the oxygen blowing nozzle 9 of the oxygen lance 13 was set to 60 m.
/ S was blown out of oxygen. As a result, no ash was observed.

Table 1 shows the oxygen flow rate, furnace temperature, ash surface temperature, molten slag temperature, and molten slag amount at that time. (Comparative Example 1) As shown in FIG. 2, a combustion apparatus not using an oxygen lance was used, and other conditions were the same as in Example 1 to melt ash. The results are shown in the table. (Comparative Example 2) As shown in FIG. 2, a combustion apparatus not using an oxygen lance was used, and oxygen-enriched combustion air was supplied to a heating burner. Melting was performed. The results are shown in the table.

[0026]

[Table 1]

In order to increase the temperature of the molten slag, oxygen enrichment (Comparative Example 2) is also possible. However, in this case, the furnace temperature has increased by 60 ° C. as compared with the air combustion (Comparative Example 1).

When the combustion apparatus using the oxygen lance of the present invention is used, the furnace temperature is lower by 54 ° C. than when oxygen is enriched, and the amount of oxygen used is 6 Nm ³ / h less. The ash surface temperature is 82 ° C and the molten slag temperature is 59 ° C higher, resulting in a molten slag amount of 5 kg / h.
Was also found to increase. That is, a large effect was obtained with a small amount of oxygen.

[0029]

According to the present invention, in the ash melting furnace for melting incineration ash and fly ash, the temperature of the front end of the combustion flame can be partially increased, and as a result, the temperature in the furnace is greatly increased. Thus, the temperature of the molten slag can be increased without increasing the furnace wall material. Further, at this time, since the molten slag can be generated without scattering the ash, the efficiency of the treatment can be increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an outline of a usage state of a combustion device of the present invention in a powder melting furnace.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ash 2 molten slag 3 furnace wall material 4 heating burner 5 flammable substance introduction pipe 6 combustion air introduction pipe 7 combustion flame 8 oxygen introduction pipe 9 oxygen blowing nozzle 10 oxygen blowing direction 11 slag port 12 combustion flame tip 13 oxygen lance 14 Oxygen lance insertion hole 15 Combustion flame center 16 Boss 17 Nut

Claims (3)

[Claims] 1. A combustion apparatus for a powder melting furnace which blows a combustion flame downward from a heating burner attached to a wall of a melting furnace for powder such as incineration ash, fly ash or sewage sludge. An oxygen lance for blowing oxygen to the combustion flame of the heating burner to raise the temperature of the flame, the oxygen lance being attached to the furnace wall material. 2. The combustion apparatus according to claim 1, wherein a portion of oxygen blown from the oxygen lance to the combustion flame is a tip of the combustion flame. 3. The combustion apparatus according to claim 1, wherein the flow rate of the oxygen blown from the lance is 60 m / s or less.