JP3310812B2 - Melt combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for melting and burning a fuel containing a non-combustible substance or a flame-retardant substance. The present invention relates to a coal-fired boiler, a sludge-fired boiler, various waste combustion facilities, and heavy oil pre-combustion. It can be applied to various turning combustor such as a burner or _the NO _x reduction burner.

[0002]

2. Description of the Related Art FIG. 4 is an upward horizontal sectional view (a sectional view taken along the line IV-IV in FIG. 5) of an example of a conventional melt-burning apparatus, and FIG. It is a longitudinal cross-sectional view. In these figures, (1) is a melting and burning apparatus main body, (2) is a refractory material, (3) is an outer plate, (4) is a pulverized coal nozzle inner cylinder,
(5) is a pulverized coal nozzle outer cylinder, (6) is a flame holding plate, (7)
(a), (7b), (7c), and (7d) show a swirling secondary air nozzle, and (15) shows a heavy oil burner.

[0003] A cylindrical and rigid molten combustion apparatus main body (1)
Has a refractory material (2) lined on an outer plate (3). A pulverized coal nozzle inner cylinder (4) and a pulverized coal nozzle outer cylinder (5) disposed along the axis at the upper end of the molten combustion device main body (1).
And a mixture of pulverized coal and primary air is supplied between them, and a flame holding plate (6) attached to the tip of the pulverized coal nozzle inner cylinder (4)
Is injected into the molten combustion device main body (1) at a constant spread angle. The temperature of the melt combustion device main body (1) is increased by burning heavy oil by a heavy oil burner (15). on the other hand,
The secondary air is swirled secondary air nozzles (four arranged in the illustrated example) (7a), (7b),
From (7c) and (7d), they are fed into a so-called tangential.

[0004] The pulverized coal charged into the main body of the melting and burning apparatus (1) is gasified and burned at a high temperature while rotating at high speed together with the secondary air. On the other hand, the ash contained in the pulverized coal melts under high temperature and is melted by centrifugal force.
To form a molten slag layer and flow down the wall.

[0005]

The above-mentioned conventional melting and burning apparatus has the following problems to be solved.

[0006] 1) When the combustion load of the melting and burning apparatus is reduced, the air is supplied from the swirling secondary air nozzles (7a), (7b), (7c) and (7d) in order to keep the air ratio of the entire combustion apparatus constant. Reduce the amount of secondary air. Then, the turning force decreases. When the swirling force decreases, the rate at which the molten ash reaches the inner wall surface of the molten combustion device main body (1) decreases, and the gas residence time in the molten combustion device decreases. Experiments have shown that lowering the combustion load lowers the slugging rate (molten ash recovery rate) and combustion efficiency, and lowers the performance of the molten combustion apparatus.

2) When a fuel having poor flammability, that is, a fuel having a small amount of volatile matter and a high ash melting point is used, the fuel collides against a wall surface before the fuel is ignited and melted, so that the refractory material 2 is significantly worn. Instead, chars are buried in the molten slag beforehand, resulting in agglomeration combustion in which coke (a lot of which is in advance) is formed due to lack of oxygen, and both the slugging rate and the combustion efficiency decrease.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention provides a fuel injection nozzle having a cylindrical shape with a vertical axis, a fuel injection nozzle at the upper end along the axis, and a horizontal and radial With air injection nozzles deviated from the direction, the air injection nozzle is fixed to a vertical drive shaft.
Supported so as to be able to swing around the drive shaft so as to change the bias angle of the air injection nozzle with respect to the radial direction.
The present invention proposes a melt combustion device characterized by the following.

[0009]

[Function] When the combustion load is high, since the turning force is large and the time to reach the wall surface is short, the drive shaft is rotated so as to prevent the fuel from reaching the wall surface before ignition / melting, and the deflection angle of the air injection nozzle is reduced. By turning inward, a so-called virtual circle (a circle in which the axes of all the air injection nozzles are in contact in the plan view) is reduced. Conversely, when the combustion load is small, in order to compensate for the decrease in the turning force, the drive shaft is rotated to make the deviation angle outward, that is, to increase the virtual circle.

[0010]

FIG. 1 is a horizontal sectional view (sectional view taken along the line II of FIG. 2) of an embodiment of a melt-burning apparatus according to the present invention, which is cut at an upper portion, and FIG. FIG. 3 is a longitudinal sectional view taken along an arrow.
FIG. 3 is an enlarged vertical sectional view taken along line III-III of FIG. In these figures, the same parts as those in the conventional example described with reference to FIGS. 4 and 5 are denoted by the same reference numerals and their detailed description is omitted to avoid redundancy.

In this embodiment, the secondary air pipe (8
a), (8b), (8c), (8d) and the swiveling secondary air nozzles (14a), (14b), (14c), (14d), telescopic bellows (9a), (9b), (9) 9c) and (9d) are provided. And the swirling secondary air nozzles (14a), (14b),
At the root of (14c), (14d), a vertical drive shaft (10a), (10
b), (10c), (10d) are fixed, and these drive shafts are bearings (11a)
And so on. Therefore, the swiveling secondary drive nozzles (14a), (14b), (14c), (14d) can swing around the vertical drive shafts (10a), (10b), (10c), (10d), and melt. The deviation angle θ of the combustion device body (1) with respect to the radial direction can be changed. Drive shaft (10
a), (10b), (10c), and (10d) have levers (12a), (12
b), (12c) and (12d) are fixed, and this lever (12
By operating a), (12b), (12c), and (12d), the drive shafts (10a), (10b), (10c), and (10d) rotate, and the rotating shaft fixed to the drive shaft is rotated. Secondary air nozzles (14a), (14b), (14
c) and (14d) move to adjust the blowing angle of the secondary air. (13a), (13b), (13c), and (13d) are angle indicating plates.

When the combustion load is high, the swirling secondary air nozzles (14a), (14b), (14c) and (14d) face inward (solid lines in FIG. 1).
To prevent fuel from reaching the wall before ignition and melting. Conversely, when the combustion load is reduced, the swirling secondary air nozzles (14a), (14b), (14c), and (14d) face outward (FIG. 1).
By setting the middle circle (dashed line), the above-mentioned virtual circle is enlarged to suppress a decrease in the turning force due to a decrease in the combustion load. In addition to the case where the combustion load changes, the swirling secondary air nozzles (14a) and (1a) depend on the type of fuel used and the required air ratio.
By appropriately adjusting the angles of 4b), (14c) and (14d), it contributes to the improvement of the slugging rate and the combustion efficiency.

[0013]

According to the present invention, the air in the melting and burning apparatus is
By adjusting the bias angle of the swirling air injection nozzle by rotating the drive shaft of the injection nozzle, the type of fuel, combustion load,
Optimum turning conditions are given according to combustion conditions such as air ratio,
It is possible to stabilize ignition and improve combustion efficiency and slagging rate.

[Brief description of the drawings]

FIG. 1 is a horizontal cross-sectional view (a cross-sectional view taken along the line II of FIG. 2) of an embodiment of a melting and burning apparatus according to the present invention, which is cut at an upper portion.

FIG. 2 is a vertical sectional view taken along the line II-II in FIG.

FIG. 3 is an enlarged vertical sectional view taken along the line III-III of FIG. 1;

FIG. 4 is an upward horizontal cross-sectional view (a cross-sectional view taken along the line IV-IV in FIG. 5) showing an example of a conventional melt-burning apparatus by cutting an upper part thereof;
It is.

FIG. 5 is a vertical sectional view taken along the line VV of FIG. 4;

[Explanation of symbols]

 (1) Melting combustion equipment main body (2) Refractory material (3) Outer plate (4) Pulverized coal nozzle inner cylinder (5) Pulverized coal nozzle outer cylinder (6) Flame holding plate (7a), (7b), (7c) , (7d) Swirling secondary air nozzle (8a), (8b), (8c), (8d) Secondary air pipe (9a), (9b), (9c), (9d) Telescopic bellows (10a), ( 10b), (10c), (10d) Drive shaft (11a) Bearing (12a), (12b), (12c), (12d) Lever (13a), (13b), (13c), (13d) Angle indicator (14a), (14b), (14c), (14d) Swirling secondary air nozzle

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Akiyasu Okamoto 5-717-1 Fukahori-cho, Nagasaki-shi Mitsubishi Heavy Industries, Ltd. Nagasaki Research Laboratory (56) References JP-A 1-312384 (JP, A) JP-A-57-55313 (JP, A) JP-A-5-8237 (JP, A) JP-A-61-49916 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23G5 / 32 F23D 1/02 F23D 17/00 F23L 9/00

Claims (1)

(57) [Claims] In 1. A axis vertical cylindrical, with comprises a fuel injection nozzle along the axis at the upper end, in that includes a biased air injection nozzle with respect to the horizontal and radially to the upper side wall, said air injection The nozzle is fixed to a vertical drive shaft and is not swingably supported around the drive shaft so as to change the angle of deviation of the air injection nozzle with respect to the radial direction.
Melt combustion apparatus, characterized in that that.