JPH11325444A - Burner type swirling melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strengthen a swirling flame with a simplified structure. SOLUTION: A burner type swirling melting furnace 1 includes a cylindrical heat resistant wall with a burner 5 provided on the wall. The burner 5 is fixed at an angle where an infection direction of the burner 5 makes contact with a tangential line of a virtual circle 7 having a predetermined radius in a furnace 6. The burner 5 has a triple structure, in which it includes a core tube provided most thereinside for injecting incineration ash together with air, an inner tube provided around the periphery of the former for injecting a fuel, and an outer tube provided on the periphery of the former core tube for supplying air into the furnace 6. The melting furnace 1 uses the integral burner 5 to effectually form a swirling flame.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner-type rotary melting furnace for melting incinerated ash of various kinds of waste, for example, incinerated ash such as sewage sludge to form slag.

[0002]

2. Description of the Related Art There is an increasing need to melt sewage incineration ash, to recycle it, and to recycle it. In particular, there is an increasing need to construct a melting furnace for incineration ash generated from existing incinerators. Against this background, sewage sludge incineration facilities generally do not have a power generation facility, so there is a greater need for burner-type melting furnaces that use fuel than plasma melting furnaces that use electric power. FIGS. 5 and 6 are horizontal cross-sectional views showing a mounted state of a burner in a conventional burner type rotary melting furnace. As shown in FIG. 5, the melting furnace 3 having a circular cross section
In 1, a pair of burners 33 and 34 are provided on a wall 32. The burner 33 converts fuel such as heavy oil and combustion air into the furnace 3.
7, and the other burner 34 has a structure capable of injecting incinerated ash powder and combustion air. In addition, the melting furnace 31 shown in FIG. 6 has four burners 35 and 36 disposed on the wall 32, and the pair of burners 35 has a structure capable of injecting incineration ash, air, and fuel into the furnace 37. The other pair of burners 36 has a structure that can inject incineration ash.

In the melting furnace 31 described above, an imaginary circle 38 having a certain diameter is set in the furnace 37, and in both figures, an axis 39 of the burner in the furnace is directed in such a manner as to contact the imaginary circle 38. Each burner 33-36 is arranged. With such a configuration, the inside of the furnace 37 is connected to the burners 33 to 36.
The fuel and the combustion air injected into the furnace 37 are injected into the furnace 37 along the axis 39 to form a stable swirling combustion flame and burn and melt the incineration ash.

[0004]

As described above, in the conventional burner-type swirling melting furnace, incineration ash, fuel, and air are often injected into the furnace by different burners. In addition, there was a view that the use of a plurality of burners can provide a smooth turning flame. However, when multiple burners are used, the swirl is formed smoothly, but the flow rate of fuel and the like per burner decreases,
The turning force is not always in the best condition. Furthermore, incineration ash,
Since there are a plurality of facilities for supplying fuel and air, the structure of the melting furnace is large and complicated, and the construction cost is high. The present invention has been made in view of the above problems, and an object of the present invention is to provide a burner-type swirling melting furnace that can strengthen a swirling flame with a simple structure.

[0005]

In order to achieve the above object, the present invention provides a burner-type swirling melting furnace comprising a cylindrical furnace body provided with a burner in a direction along an inner peripheral surface thereof. The burner is an integrated burner capable of simultaneously supplying incineration ash, fuel and combustion air, and a single-body burner is provided at one location of the furnace body. In this specification, incineration ash is not limited to sewage sludge incineration ash, but means various types of incineration ash, and may be simply referred to as ash. The burner is
It is preferable to have a triple structure in which ash and carrier air are supplied from the center, fuel is supplied from the outer periphery, and combustion air is further supplied from the outer periphery.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a burner-type swirling melting furnace according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a burner-type swirling melting furnace 1 and a secondary combustion chamber 2 and a slag removal chamber 3 attached thereto. The melting furnace 1 has a cylindrical heat-resistant wall portion 4, and the wall portion is provided with substantially one burner 5. As shown in FIG. 2, the burner 5 is fixed such that the injection direction of the burner 5 is directed tangentially to a virtual circle 7 having a predetermined diameter in the furnace 6.

FIG. 3 is an enlarged view of the burner 5. The burner 5 has a triple structure. A core pipe 8 for injecting air and incineration ash into the furnace 6 is provided at the innermost side in the radial direction, and an inner pipe 9 for injecting fuel is provided on the outer periphery thereof. Into the furnace 6
Is provided with an outer tube 10 for supplying to the outer tube. Thus burner 5
Can integrally inject incinerated ash powder, combustion fuel and combustion air. The burner 5 is provided with a swirl swirler 11. The structure of the swirling swirler 11 is composed of a number of guide vanes at an angle in the direction of flow of the fluid, the burner outer tube 10 is fixed to the wall 4, and the fuel and air are separated by the swirling swirler 11. A turn can be applied. As for the other auxiliary equipment of the burner-type swirling melting furnace, since a conventional technique is used, a detailed configuration thereof is omitted.

Next, the operation of the burner type rotary melting furnace will be described. When the melting furnace 1 operates, the core tube 8 of the burner 5,
Incineration ash, fuel and air are blown out from the inner pipe 9 and the outer pipe 10, respectively. The burner 5 is an integrated burner, and the generation of a swirling flame in the initial stage is somewhat slow. However, since the jet flow velocity from the burner 5 is large, a stronger swirl is applied thereafter, and a stable swirling combustion flame is formed. Slag recovery rate is improved. That is, the incineration ash injected from the core pipe is injected so as to be wrapped in the fuel injected from the inner pipe 9, and the fuel is supplied from the air from the core pipe 8 inside the outer pipe and the outer pipe from the outer pipe. Combustion is efficiently carried out by the combustion air from 10 and the temperature is raised to melting. The swirling swirler 11 is provided outside the core tube 8, outside the inner tube 9, and the outer tube 1.
0, and does not rotate by itself, but can efficiently swirl the fuel flowing in the inner pipe 9 and the air flowing in the outer pipe 10, and Is melted into slag by being heated at a high temperature of about 1300 to 1600 ° C. under normal pressure, so that the melting furnace 1
Flows down to the slag removal chamber 3 below, and is discarded or reprocessed in the next step. On the other hand, the gas burned in the furnace 6 rises and is introduced into the secondary combustion chamber 2, and is discharged after being processed in a downstream process.

FIG. 4 shows the results of a melting test of an integrated burner type rotary melting furnace according to the present embodiment (Example) and a melting furnace using a plurality of burners of a conventional (comparative example). The sewage sludge incineration ash was melted using a swirling melting furnace under the same conditions, and a test was performed by changing the blowing of combustion air, and the swirling force and slag recovery rate were examined. As a result, one burner was added to the melting furnace.
It was found that the one blown by using this method was superior in both the slag recovery rate and the number of swirls to that blown by two. Of these, the slag recovery rate indicates what percentage of the incinerated ash charged into the furnace was recovered, and the comparative example was 71%.
On the other hand, it was 75% in this example. The effective swirl number was 6.6 in the comparative example, whereas it was 8.3 in the present example. Here, the effective swirl number is an index indicating the swirling strength of a combustion gas in a certain cross section in the furnace, and the larger the index value is, the larger the swirling force of the combustion gas is, that is, the swirling combustion flame vortex is It means that it is formed stably.

As described above, according to the present embodiment, the slag recovery rate and the swirling combustion flame vortex are formed stably, so that the combustion efficiency of incinerated ash can be improved. Although the cost of the burner itself is increased by integrating the burner (single), the melting furnace structure is simplified because the fuel piping and air piping facilities are reduced, and the size of the entire furnace is reduced and the cost is reduced. Can be lowered. The embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments, and various modifications can be made based on the technical idea of the present invention. For example,
In the above embodiment, the burner has a triple structure, but may have a double structure or a quadruple structure or more. Further, the types of the media ejected from the core tube 8, the inner tube 9, and the outer tube 10 can be arbitrarily changed.

[0011]

As described above, in a burner-type swirling melting furnace in which a burner is provided in a tangential direction of the inner peripheral surface of a cylindrical furnace body, the burner is used to simultaneously convert ash, fuel and combustion air. Since an integrated burner that can be supplied is provided and a single-body burner is provided at one place of the furnace main body, the recovery rate of slag can be improved, and the melting furnace can be reduced in size and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a melting furnace of a burner type rotary melting furnace according to an embodiment of the present invention and equipment attached thereto.

FIG. 2 is a cross-sectional view taken along line XX in FIG.

FIG. 3 is an enlarged view of a burner of the burner type rotary melting furnace according to the embodiment of the present invention.

FIG. 4 is a diagram showing the results of a melting test of an integrated burner type rotary melting furnace according to the present embodiment and a melting furnace using a plurality of conventional burners (comparative example).

FIG. 5 is a schematic horizontal sectional view of a conventional burner-type swirling melting furnace equipped with two burners.

FIG. 6 is a schematic horizontal sectional view of a conventional burner-type swirling melting furnace to which four burners are attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Melting furnace 2 Secondary combustion chamber 3 Slag removal chamber 4 Heat resistant wall 5 Burner 6 Furnace 7 Virtual circle 8 Core tube 9 Inner tube 10 Outer tube 11 Rotating swirler

Continued on the front page (72) Inventor Toshio Goda 12 Nishiki-cho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Heavy Industries, Ltd. Inside Yokohama Works

Claims (2)

[Claims] 1. A burner-type swirling melting furnace comprising a cylindrical furnace body provided with a burner in a direction along an inner peripheral surface thereof, wherein said burner is an integrated burner capable of simultaneously supplying ash, fuel and combustion air. Wherein the integrated burner is provided at one location of the furnace main body. 2. The burner according to claim 1, wherein said burner has a triple structure, wherein ash and carrier air are supplied from a central portion, fuel is supplied from an outer periphery thereof, and combustion air is further supplied from an outer periphery thereof. Swivel melting furnace.