JPH0835614A - Pulverized-coal burner - Google Patents

Abstract

PURPOSE:To provide a secondary-air nozzle around the periphery of a nozzle for a mixture of pulverized coal and primary air, relating to a burner consisting of a nozzle for the mixture whose forward end flares wide, forming a flame stabilizer, so as to prevent burnout in the burner and attachment of ash thereto. CONSTITUTION:A flame stabilizer 3 at the forward end of a nozzle 1 for a mixture gas is formed in a double structure. Slit-shaped holes 5 are opened through the inner cylinder of the flame stabilizer 3 and by axially moving the outer cylinder 4 a flow of air passed through the gap between the inner cylinder 3 and the outer cylinder 4 is blown into the furnace though the hole 5 in such a manner as to adjust the ignition point and prevent burnout in the burner and attachment of ash thereto. By striking the inner cylinder 3 with the outer cylinder 4 also the ash attaching to it is flicked off by the impact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner used in a coal-fired boiler or the like.

[0002]

2. Description of the Related Art FIG. 3 is a vertical sectional view showing an example of a conventional pulverized coal burning burner. In this figure, (1) is a mixture nozzle of pulverized coal and primary air, and (2) is a secondary air nozzle provided on the outer peripheral portion thereof. In both cases, the tip of the nozzle spreads outward and expands, which creates an ignition vortex between the primary air and the secondary air, and has the effect of holding flame.
This part is called a flame stabilizer (3).

[0003]

In the flame stabilizer provided at the tip of the conventional pulverized coal burning burner as described above, pulverized coal is conveyed with primary air in the air-fuel mixture nozzle and diffused at the tip. Therefore, it is difficult to adjust the ignition vortex that contributes to flame holding, causing burnout and ash adhesion. Also, once the ash had adhered, there was no way to remove it.

[0004]

In order to solve the above-mentioned conventional problems, the present inventor has provided a secondary air nozzle on the outer circumference of a nozzle for a mixture of pulverized coal and primary air. In the case where the tip end of the end spreads to the end spread to form a flame stabilizer, a plurality of slit-shaped holes are formed in the end spread and the outer end of the end spread can be axially moved close to the outside. The present invention proposes a pulverized coal burning burner characterized by having a cylinder.

[0005]

The present invention is constructed as described above, and a plurality of slit-shaped holes are formed in the end spread portion of the tip of the air-fuel mixture nozzle forming the flame stabilizer, and is moved axially close to the outside of the end spread portion. Since it is a double structure flame stabilizer with an outer cylinder that can be used, air is blown into the furnace from the hole of the inner cylinder, and the outer cylinder is moved to adjust the amount of air, so that the ignition point distance can be adjusted. Adjust to prevent burnout and ash adhesion. Further, the attached ash can be removed by colliding the outer cylinder with the inner cylinder.

[0006]

1 is a vertical sectional view showing an embodiment of the present invention, and FIG. 2 is an enlarged view of a portion II of FIG. In these figures, the same members as those of the conventional one described with reference to FIG. 3 are designated by the same reference numerals to avoid redundancy, and detailed description thereof is omitted.

The primary air nozzle (1) has a flame stabilizer (3) in which the tip end of the nozzle spreads outward and spreads outward.
A secondary air nozzle (2) of similar shape is provided on its outer periphery. The flame stabilizer (3) according to this embodiment has a double structure, and the flame stabilizer (3) on the inner cylinder side has several slit-shaped holes (5). Then, the outer cylinder (4) is installed slidably in the axial direction on the rail (6) in the vicinity of the outside thereof, and the adjustment rod (7) is connected to the outer cylinder (4) so that the outer cylinder (4) can slide by means not shown. it can.

In this embodiment, by sliding the outer cylinder (4), the clearance between the inner cylinder (3) and the outer cylinder (4) is adjusted to change the air passage amount. This makes it possible to change the amount of air passing through the slit-shaped hole (5).
Then, the slit-shaped hole (5) is formed in the ignition vortex generated in the flame stabilizer (3) through the primary air nozzle (2).
Since the air that has passed through hits, the ignition vortex comes close and the position of the ignition point can be adjusted.

By blowing air into the furnace through the slit-shaped holes (5), the ash is also blown off and the adhesion of the ash is prevented. If the tip end (8) of the flame stabilizer (3) is sharpened as shown in FIG. 2, the effect of preventing ash from adhering to the tip can be obtained.

Further, by rapidly sliding the adjusting rod (8) toward the tip, the tip of the outer cylinder (4) collides with the outer circumference of the inner cylinder (3), and the ash attached by the impact is removed. Can be dropped.

[0011]

The pulverized coal burning burner of the present invention uses a flame stabilizer having a double structure and a slit-like hole to prevent burning and ash adhesion by adjusting the ignition point and to prevent the inner cylinder and the outside The ash attached can be removed by colliding the cylinders.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a pulverized coal burning burner according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion II of FIG.

FIG. 3 is a vertical cross-sectional view showing an example of a conventional pulverized coal burning burner.

[Explanation of symbols]

 (1) Primary air nozzle (2) Secondary air nozzle (3) Flame stabilizer (inner cylinder) (4) Outer cylinder (5) Slit-shaped air hole (6) Slide rail (7) Adjustment rod (8) State of the art flame stabilizer

Claims (1)

[Claims] 1. A structure in which a secondary air nozzle is provided on the outer periphery of a nozzle for a mixture of pulverized coal and primary air, and the tip of the mixture gas nozzle expands toward the end to form a flame stabilizer. A pulverized coal burning burner, characterized in that a plurality of slit-shaped holes are formed in the divergent end portion, and an outer cylinder that is axially movable close to the outside of the divergent end portion is provided.