JPH09243006A - Structure of burner throat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a clinker from growing at a place near an inner side of a furnace at a burner throat. SOLUTION: Heat transfer pipes 13c to 13e positioned at an intermediate part 14 in a depth direction around a burner throat 6 are arranged in a cylindrical shape having a specified diameter. Heat transfer pipes 13b and 13a positioned at an inside part 15 of a furnace around the burner throat 6 are arranged in a slant shape with their diameters being expanded toward a furnace 1. Refractory materials 16 arranged around the burner throat 6 are formed at a cylindrical surface 17 having a specified diameter with the heat transfer pipes 13d, 13e being buried at an intermediate part 14 in a depth direction. Further, the refractory materials 16 at an inner side 15 are formed at an accute slant surface 18 expanded at an accute inclination and further the materials are formed into a gradual slant surface 19 with its diameter being expanded in such a way that the surfaces of the heat transfer pipes 13c, 13b and 13a arranged in slant form may be exposed at a location further placed more inside the furnace 1 than the accute slant shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner throat portion structure.

[0002]

2. Description of the Related Art An outline of a coal-fired boiler will be described with reference to a sectional view of FIG. 2. A plurality of burners 3 are arranged on a furnace wall 2 surrounding a furnace 1, and pulverized coal is ejected into the furnace 1. It is designed to burn.

As shown in the enlarged front view of FIG. 3, the furnace wall 2 is constituted by connecting a plurality of heat transfer tubes 4a to 4i extending in the vertical direction through fins 5, but the burner 3
In the burner throat portion 6 opened at the position (see FIG. 2), some of the heat transfer tubes 4a to 4f are bent so as to bypass the burner throat portion 6 symmetrically and further, The heat transfer tubes 4a to 4i are arranged so as to be displaced in the inner and outer directions of the furnace wall 2 so as not to interfere with each other.

As described above, at the place where the burner throat portion 6 is opened by bending the heat transfer tubes 4a to 4f, between the bent portions of the heat transfer tubes 4a to 4f, like other straight portions. Since it is difficult to connect the fins 5 to each other, the casing 20 is provided in the burner throat portion 6 and the refractory material 7 is placed therein, and the refractory material 7 is provided between the curved portions of the heat transfer tubes 4a to 4f.
By embedding, the gap is prevented from being formed.

However, since the inside of the furnace 1 on the left side of FIG. 4 becomes extremely hot due to the combustion of pulverized coal, the refractory material 7 embedded in the burner throat portion 6 toward the inside of the furnace 1 is used.
Cannot expect the cooling effect of the heat transfer tube 4a, and the surface temperature thereof rises remarkably.

On the other hand, the refractory material 7 embedded from the middle portion of the burner throat portion 6 in the depth direction to the outside of the furnace 1 is less affected by the heat of combustion in the furnace 1 and the heat transfer tubes 4b, The temperature rise is suppressed by the cooling effect of the water flowing in 4c.

For this reason, the refractory material 7 embedded in the burner throat portion 6 on the inner side of the furnace 1 with a remarkable temperature rise is used.
Molten ash generated by the combustion of the pulverized coal ejected from the burner 3 is likely to adhere to the surface of the, and the clinker 8 grows largely as shown in FIG. 4 due to the adhesion of the molten ash.

[0008]

When the clinker 8 grows largely inside the furnace 1 of the burner throat section 6, the clinker 8 enters the range of the combustion path of the pulverized coal ejected from the burner 3,
Although the pulverized coal may be reflected by the clinker 8 and burned outside the furnace 1, the clinker 8 that has grown greatly naturally falls into the furnace 1 from the burner throat section 6 due to its own weight.

Therefore, as shown in FIG. 2, a clinker hopper 9 is provided in the lower part of the furnace 1, and the clinker 8 dropped from the burner throat section 6 into the furnace 1 falls into the clinker hopper 9. It is designed to be cooled with cooling water.

The clinker 8 dropped into the clinker hopper 9 is guided from the gate 10 to the crusher 11, crushed, sucked by the high-pressure water pipe 12 through which high-pressure water flows, and discharged from the clinker hopper 9. There is.

However, as described above, when the clinker 8 grows largely inside the furnace 1 of the burner throat section 6, it interferes with the combustion of the pulverized coal ejected from the burner 3 or the large clinker 8 enters the furnace 1. If dropped, there is a problem that the heat transfer tube at the bottom of the furnace is damaged or the clinker hopper 9 is clogged.

The present invention solves such a problem and prevents the clinker from growing greatly inside the burner throat near the inside of the furnace, thereby hindering combustion, damaging the heat transfer tube at the bottom of the furnace, and clinker hopper. It is an object of the present invention to provide a burner throat part structure in which clogging of a cylinder does not occur.

[0013]

SUMMARY OF THE INVENTION According to the present invention, a plurality of heat transfer tubes are bent so as to bypass the burner throat section symmetrically, and a plurality of heat transfer tubes located in an intermediate portion in the depth direction around the burner throat section are provided. Arranged in a cylindrical shape with a constant diameter, the plurality of heat transfer tubes located inside the furnace around the burner throat part are arranged in an inclined shape whose diameter increases toward the furnace, and the refractory material provided around the burner throat part is arranged in the burner throat part. In the middle part in the peripheral depth direction, a plurality of heat transfer tubes arranged in a cylindrical shape having a constant diameter are embedded to form a cylindrical surface having a constant diameter, and the refractory material is provided inside the furnace surface from the cylindrical surface having the constant diameter. Formed on a steeply inclined surface that spreads with a steep inclination, and the diameter of the heat transfer tubes arranged in an inclined shape in which the diameter expands further inside the furnace than the steeply inclined surface so that the surface is exposed. Expanded Regarding the burner throat structure characterized by being formed on an inclined surface, the refractory material was expanded by a steep slope inside the furnace, and the surface of the heat transfer tube was exposed further inside the furnace than the steep slope. Since it is a gently sloping surface, the temperature rise of the gently sloping surface of the refractory material inside the furnace of the burner throat is suppressed by the cooling effect of the water flowing in the heat transfer tube, so it is difficult for molten ash to adhere and clinker growth Will not do.

[0014]

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

FIG. 1 is a sectional view showing an example of the embodiment of the present invention as seen from the same direction as FIG. 4, and in order to open the burner throat portion 6, it detours symmetrically as in FIG. Heat transfer tubes 13a to 1 that are bent like
Of the 3i, the plurality of heat transfer tubes 13c to 13e located in the intermediate portion 14 in the depth direction (the left-right direction in FIG. 1) around the burner throat portion 6 are all arranged in a cylindrical shape having a constant diameter. Reference numerals 13j to 13k denote straight tubes forming the furnace wall.

A plurality of heat transfer tubes 1 are provided around the burner throat portion 6 inside the furnace 15 with respect to the intermediate portion 14.
3b and 13a are arranged in an inclined shape whose diameter gradually increases from the heat transfer tube 13c toward the furnace 1.

The heat transfer tubes 13f to 13i located outside the furnace 1 with respect to the intermediate portion 14 are arranged in an inclined shape whose diameter gradually increases toward the outside of the furnace 1.

Each heat transfer tube 13 in the burner throat section 6
A casing 20 is provided on the outer peripheral side of a to 13i and on the inner peripheral side of the heat transfer tubes 13f to 13i located outside the furnace 1, and the refractory material 16 embedded between the curved portions of the heat transfer tubes 13a to 13i is provided. The refractory material 16 is cast, and the plurality of heat transfer tubes 13c to 13e located in the intermediate portion 14 in the depth direction around the burner throat portion 6 and the heat transfer tubes located outside the furnace 1 with respect to the intermediate portion 14. For 13f to 13i, these heat transfer tubes 13c to 13i are embedded so that a cylindrical surface 17 having a constant diameter is formed in the intermediate portion 14.

The refractory material 16 on the inside 15 of the furnace spreads out from the above-mentioned cylindrical surface 17 of the intermediate portion 14 at a steeply steep surface 18, and the inner side of the furnace 1 further than the steep surface 18 is
A gently sloping surface 19 whose diameter increases from the heat transfer tube 13c along the inclination of the plurality of heat transfer tubes 13b, 13a arranged in an inclined shape so that the diameter increases and the surface of the heat transfer tubes 13c, 13b, 13a is exposed. Is formed in.

In the burner throat structure shown in FIG. 1 described above, the inside 1 of the furnace, which receives the heat from the combustion of pulverized coal most
The refractory material 16 of No. 5 has a plurality of heat transfer tubes 1 on the gently inclined surface 19.
Since the surfaces of 3c, 13b and 13a are exposed, the temperature rise is suppressed by the cooling effect of the water flowing through the plurality of heat transfer tubes 13c, 13b and 13a by the gently inclined surface 19 of the refractory material 16 inside the furnace 15. Therefore, the temperature does not rise to the high temperature as in the past.

Therefore, the molten ash produced by the combustion of the pulverized coal ejected from the burner 3 is less likely to adhere to the gently sloped surface 19 of the refractory material 16 inside the furnace 15 of the burner throat section 6, and the clinker is the burner. The throat part 6 falls inside the furnace 1 before it grows and falls.

[0022]

According to the present invention, since the surface of the refractory material inside the furnace of the burner throat section suppresses the temperature rise due to the cooling effect of the water flowing through the heat transfer tube, and the molten ash hardly adheres,
The clinker will fall inside the furnace at the burner throat before it grows, hindering combustion, or the grown clinker will fall and damage the heat transfer tube at the bottom of the furnace or clog the clinker hopper. There is an effect that does not happen.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing an outline of a coal-fired boiler.

FIG. 3 is an enlarged front view of a conventional burner throat structure.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 furnace 6 burner throat part 13a-13i heat transfer tube 14 middle part 15 furnace inner side 16 refractory material 17 cylindrical surface 18 steep slope 19 gentle slope

Claims (1)

[Claims] 1. A plurality of heat transfer tubes are bent so as to bypass the burner throat section symmetrically, and the plurality of heat transfer tubes located in an intermediate portion in the depth direction around the burner throat section are arranged in a cylindrical shape having a constant diameter. A plurality of heat transfer tubes located inside the furnace around the burner throat section are arranged in an inclined shape whose diameter increases toward the furnace, and a refractory material provided around the burner throat section is provided at an intermediate portion in the depth direction around the burner throat section. Is a cylindrical surface having a constant diameter formed by embedding a plurality of heat transfer tubes arranged in a cylindrical shape having a constant diameter, and the refractory material is expanded at a steep inclination inside the furnace from the cylindrical surface having the constant diameter. It was formed on a steeply inclined surface, and on the inside of the furnace further than the steeply inclined surface, it was formed on a gently inclined surface with an enlarged diameter so that the surfaces of a plurality of heat transfer tubes arranged in an inclined shape in which the diameter is expanded are exposed. Special Burner throat structure to be considered.