JP2002195518A - Ash melting burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that incineration ash can not be melted efficiently when a prior art circular burner is applied to an incineration ash melting furnace because the circular burner heats the incineration ash uniformly and can not perform spot heating and because the incineration ash is scattered by the flame jet of the burner caused by swirling air, and a problem that the scattering incineration ash adheres to the burner or a burner tile to change the flame shape and corrosive components in the incineration ash cause corrosion. SOLUTION: The burner comprises a gas supply pipe 3 installed concentrically in a burner tile 2 disposed on the downstream side of a wind box 1, a gas nozzle 6 disposed on the forward end side of the gas supply pipe, a flame holding plate 7 disposed on the upstream side thereof, and an air swirler 9 disposed on the farther upstream side. The burner tile is provided with an enlarging opening 5 having an opening angle α of 0-45 deg. on the downstream side of a straight tubular section 4 and the gas nozzle has a gas jet angle θ larger than the opening angle. The ash melting furnace is arranged such that the end part of the enlarging opening or the vicinity thereof is located on the extension thereof in the jetting direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ash melting burner for use in an incineration ash melting furnace for melting incinerated ash such as municipal waste.

[0002]

2. Description of the Related Art As a conventional swivel burner, for example, FIG.
There is something like that shown in The swirl burner will be described with reference to the drawing. In the swirl burner, a gas supply pipe c is installed concentrically in a burner tile b provided downstream of a wind box a,
A gas nozzle d is provided at the tip side of the gas supply pipe c,
The basic configuration is such that a flame holding plate e is provided on the upstream side and an air swirler f is further provided on the upstream side.

[0003] The burner tile b has a flared divergent opening h having a curvature or an angle downstream of the straight pipe g, and the gas nozzle d is located inside the straight pipe g remote from the divergent opening h. Has been placed. The gas nozzle d is configured to inject gas in a radial direction, that is, in a direction perpendicular to the gas supply pipe c, to promote mixing with the air swirling flow downstream of the air swirler f. .

The air supplied from the air supply pipe i into the wind box a is prevented from drifting by the draft tube j provided on the upstream side of the burner tile b and is supplied into the burner tile b. Preheated air is used as air, and a heat insulating layer k is provided in the wind box a to prevent the temperature of the preheated air from lowering.

[0005] In such a swirling burner, the mixing of the flame holding and the gas is promoted by using the strong swirling flow of the air, so that high load and short flame combustion are realized, and the mixing of the gas and the air is relatively good. Therefore, the flame becomes an inflame flame, and there is an advantage that a wide area can be uniformly heated as a flat frame burner.

FIG. 4 conceptually shows a desirable flame shape of a burner m in a general furnace for melting incineration ash such as municipal waste. That is, n is a melting furnace, o is incineration ash,
In such a melting furnace n, it is more important to heat the melting point p intensively than to uniformly heat the incineration ash o in order to efficiently melt the incineration ash o, At this time, incineration ash o by jet q from burner m
It is necessary to avoid scattering as much as possible.

[0007]

However, when the above-described swirling burner shown in FIG. 4 is applied to an incineration ash melting furnace as shown in FIG. 5, the swirling burner heats the incinerated ash uniformly. The melting point cannot be heated and melted intensively. Further, since the swirling of the air is too strong, the incinerated ash is scattered by the jet of the flame from the burner, and the incinerated ash cannot be melted efficiently. The scattered incinerated ash adheres to a burner or a burner tile to change the shape of the flame or to cause problems such as erosion due to the influence of corrosive components contained in the incinerated ash. Therefore, an object of the present invention is to solve such a problem.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a gas supply pipe is installed concentrically in a burner tile provided on the downstream side of a wind box, and a gas supply pipe is provided at a tip side of the gas supply pipe. In a burner provided with a gas nozzle, a flame holding plate on the upstream side and an air swirler further on the upstream side, the burner tile forms a divergent opening having an opening angle of 0 to 45 degrees on the downstream side of the straight pipe part. At the same time, the gas nozzle proposes an ash melting burner in which the gas injection angle is larger than the opening angle and the end of the divergent opening or the vicinity thereof is located on the extension of the injection direction.

According to the present invention, in the above configuration,
It is proposed to arrange the gas nozzle from the straight pipe portion to the start position of the divergent opening or in the vicinity thereof.

In the present invention, it is proposed that the air swirler be constituted by an axial swirling blade in the above structure.

Further, in the present invention, it is proposed that in the above-mentioned structure, a primary air hole is formed in the flame holding plate.

Further, the present invention proposes, in the above configuration, to set the flow velocity of the air swirling through the air swirler to be lower than the flow velocity of the gas injected from the gas nozzle.

Further, the present invention proposes, in the above configuration, that the combustion air supplied through the wind box is preheated air, and the wind box is provided with an air insulation layer having a pressure release hole.

In the ash melting burner of the present invention described above, the flame does not spread on a plane unlike the flat frame burner, and a flame capable of intensively heating a limited area can be obtained. In addition, the flow velocity of the air swirling through the air swirler is set to be lower than the flow velocity of the gas injected from the gas nozzle. For this reason, the air becomes a gentle swirling flow, and since the flow velocity itself is slow, there is no scattering of incineration ash.

[0015]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of an ash melting burner according to the present invention, and FIG. 2 is a view taken in the direction of arrow A in FIG. In these figures, reference numeral 1 denotes a wind box, 2 denotes a burner tile provided on the downstream side of the wind box 1, and a gas supply pipe 3 is installed concentrically inside the burner tile 2. Burner tile 2
Forms a divergent opening 5 downstream of the straight pipe section 4,
Indicates the opening angle of the divergent opening 5. In the present invention, the opening angle α is set to 0 to 45 degrees. A gas nozzle 6 is provided on the tip side of the gas supply pipe 3, and the gas nozzle 6 is arranged corresponding to a start position 16 of the divergent opening 5 from the straight pipe 4 of the burner tile 2. The gas nozzle 6 is configured to inject gas at a predetermined angle forward, and θ indicates the injection angle. As shown in the drawing, the injection angle θ of the gas nozzle 6 is configured to be larger than the opening angle α of the divergent opening 5, and as shown by the broken line in the drawing, the divergent opening 5 extends It is configured so that the end is located. Gas supply pipe 3
Has a flame holding plate 7 on the upstream side of the gas nozzle 6,
The flame holding plate 7 is smaller than the inner diameter of the straight pipe portion 4 and has a plurality of primary air holes 8 provided on the circumference. Further, an air swirler 9 having axial flow swirling blades is provided further upstream than the flame holding plate 7.

The wind box 1 has an air insulation layer 10 as a double structure and can supply preheated air from an air supply pipe 11. Pressure relief holes 12 are provided corresponding to the thermal expansion of the air in the heat insulating layer 10. A draft tube 13 is provided in the wind box 1 on the downstream side of the burner tile 2. In the drawing, reference numeral 14 denotes a pilot burner insertion hole, and ignition is performed by a pilot burner (not shown) externally provided in the pilot burner insertion hole 14. The pilot burner is selected so as not to be blown out by the swirling flow of air. Reference numeral 15 denotes a flame detection hole. The flame detection hole 15 is provided at an appropriate position in consideration of the turning direction of air and the flame length of the pilot burner.

In the above configuration, when the preheated air preheated to several hundred degrees by another process is supplied from the air supply pipe 11 into the wind box 1, the preheated air is prevented from drifting by the draft tube 13. In this state, the gas flows between the straight pipe portion 4 of the burner tile 2 and the gas supply pipe 3, and becomes a swirling flow by an axial swirling blade in the air swirler 9.
Along the wall of the divergent opening 5 at an angle α into the furnace. On the other hand, the gas supplied by the gas supply pipe 3 is injected from the gas nozzle 6 toward the end of the divergent opening 5 at an injection angle θ, and is mixed with the swirling air and burned. On this occasion,
The pressure of the gas supplied by the gas supply pipe 3 is set higher than the pressure of the combustion air.

In the above combustion, since the opening angle of the divergent opening 5 of the burner tile 2 is set to 0 to 45 degrees,
The flame does not spread on a flat surface like a flat flame burner, and a flame that can heat a limited area intensively is obtained. At this time, the pressure of the gas supplied by the gas supply pipe 3 is set higher than the pressure of the combustion air, and the flow velocity of the air swirling through the air swirler 9 is made higher than the flow velocity of the gas injected from the gas nozzle 6. Also set late. For this reason, the air becomes a gentle swirling flow, and since the flow velocity itself is slow, there is no scattering of incineration ash.

In the above combustion, the air swirler 9
The swirled air forms a stable recirculation flow downstream of the flame stabilizer 7. On the other hand, the air flow from the primary air holes 8 of the flame holding plate 7 is mixed with a part of the gas injected at the injection angle θ, and the recirculation flow forms a stable pilot flame and stably holds the main flame. .

On the other hand, the gas is sprayed from the gas nozzle 6 at an injection angle θ.
Is injected in the direction of the end of the divergent opening 5, so that the gas jet reaches the air jet, that is, the swirling flow, as compared with a conventional burner in which gas is jetted at right angles to the air flow. Becomes longer. Therefore, the ratio of gas entrained in the swirling air flow decreases, so that a low oxygen region is generated downstream of the gas nozzle 6 and downstream of the flame holding plate 7, that is, in the center of the flame. Generates a bright flame. Thermal decomposition of the gas is more likely to occur as the temperature of the preheated air is higher, and the brightness of the flame is higher.

Further, in the above embodiment, the flame holding plate 7
Since the primary air holes 8 are provided, it is not necessary to separately install a primary air supply pipe, a simple burner structure is provided, maintenance becomes easy, and provision can be made at low cost.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the ash melting burner of the present invention described above, the number of axial-flow type swirling blades constituting the air swirler 9 is set to six.
The gas nozzle 6 has a swirl angle of 45 degrees, the divergent opening 5 of the burner tile 2 has an opening angle of 30 degrees, and the end of the divergent opening 5 is positioned on the extension of the injection direction. Assuming that the pre-heated air and gas are appropriately adjusted and supplied at an injection angle θ of 60 degrees, a low-speed bright flame having a flame length of about 1 to 1.5 m and capable of intensively heating and melting a limited area is formed. Was completed.

In the above-described embodiment or example, the gas nozzle 6 is arranged so that the end of the divergent opening 5 is positioned on the extension of the jetting direction. Needless to say, they may be appropriately shifted to the side.

[0024]

As described above, the present invention has the following effects. a. By appropriately setting the opening angle of the divergent opening of the burner tile, the position and injection angle of the gas nozzle, and the turning angle of the air swirler, a flame suitable for melting ash such as incineration ash, that is, a flame length of, for example, 1 to 1 At about 0.5 m, a low-speed bright flame capable of intensively heating and melting a limited area can be formed. b. Since a gentle air swirling flow having a low flow velocity is formed, ash is not scattered and melting can be performed efficiently. c. By providing the primary air hole in the flame holding plate, it is not necessary to separately install a primary air supply pipe, and a simple burner structure is provided, which facilitates maintenance and can be provided at low cost. d. By providing the air box with a pressure relief hole in the wind box, the weight of the entire burner is reduced, and the ease of maintenance is improved.

[Brief description of the drawings]

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

FIG. 2 is a view as viewed in the direction of the arrow A in FIG.

FIG. 3 is a longitudinal sectional view of a conventional swivel burner.

FIG. 4 conceptually shows a desirable flame shape of a burner in a general furnace for melting incineration ash such as municipal solid waste.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wind box 2 burner tile 3 gas supply pipe 4 straight pipe section 5 divergent opening 6 gas nozzle 7 flame holding plate 8 primary air hole 9 air swirler 10 air insulation layer 11 air supply pipe 12 pressure relief hole 13 draft tube 14 pilot burner Insertion hole 15 Flame detection hole 16 Start position

Claims (6)

[Claims] 1. A gas supply pipe is installed concentrically in a burner tile provided downstream of a wind box, a gas nozzle is provided at a tip side of the gas supply pipe, a flame holding plate is provided upstream of the gas nozzle, and a further upstream side is provided. In a burner provided with an air swirler, the burner tile forms a divergent opening having an opening angle of 0 to 45 degrees downstream of the straight pipe portion, and the gas nozzle makes the gas injection angle larger than the opening angle. Ash melting burner characterized in that the end of the divergent opening or its vicinity is positioned on the extension of the injection direction. 2. The ash melting burner according to claim 1, wherein the gas nozzle is arranged corresponding to the start position of the divergent opening from the straight pipe portion or in the vicinity thereof. 3. The ash melting burner according to claim 1, wherein the air swirler is constituted by an axial swirler. 4. The ash melting burner according to claim 1, wherein a primary air hole is formed in the flame holding plate. 5. The ash melting according to claim 1, wherein the flow velocity of the air swirling through the air swirler is set lower than the flow velocity of the gas injected from the gas nozzle. Burner 6. The combustion air to be supplied through the wind box is preheated air, and the wind box is provided with an air heat insulating layer having a pressure relief hole. Ash melting burner described