JP2004012024A - Fluidized bed boiler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To normally fluidize a bed material in a fluidized bed even at a location where an opening or the like for drawing out the bed material to an air distributer is installed. <P>SOLUTION: In the fluidized bed boiler where a plurality of air nozzles 4 are arranged on the air distributer 6 being provided at the bottom of a furnace and the bed material in the fluidized bed 5 is fluidized by air from the air nozzles 4, a branch pipe 9e is mounted to a stand pipe 9b for fitting a nozzle head 9a and a nozzle head 9a' is mounted also to the tip of the branch pipe 9e at one portion of the plurality of air nozzles 4. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fluidized bed boiler, and more particularly to an air nozzle of an air distribution plate provided for fluidizing a fluidized medium.
[0002]
[Prior art]
An example of a fluidized-bed boiler that performs combustion by supplying limestone and coal will be described with reference to FIGS. 4 to 6. 4 is a side view schematically showing an example of a conventional fluidized-bed boiler, FIG. 5 is a plan view showing a part of an air distribution plate in the conventional fluidized-bed boiler, and FIG. 6 is arranged on the air distribution plate in FIG. 3 is a vertical cross-sectional view illustrating an air nozzle. The fluidized-bed boiler is vertically divided by an air distribution plate 6, the lower part is an air chamber 1, the upper part is a fluidized-bed room 5, and the air 2 supplied to the air chamber 1 is separated from the air distribution plate 6 by a predetermined distance. The fluid medium 3 in the fluidized bed chamber 5 is jetted from an air nozzle 4 erected and placed to fluidize the fluid medium 3.
[0003]
As shown in FIG. 5, the air distribution plate 6 is composed of a plurality of water wall pipes 7 arranged at a predetermined interval in the furnace bottom and a membrane bar 8 arranged so as to close between the water wall pipes 7. It is configured. As shown in FIG. 6, the air nozzle 4 is configured by attaching a nozzle head 9a to an upper end of a stand pipe (air supply pipe) 9b having a lower end erected on the membrane 8. 9c is an upper welding portion. In order to fluidize the fluidized medium 3, it is necessary to uniformly supply air to the entire area of the fluidized bed 3. Therefore, it is necessary to arrange a large number of air nozzles 4 over the entire surface of the air dispersion plate 3 as uniformly as possible.
[0004]
[Problems to be solved by the invention]
On the other hand, as shown in FIG. 5, the air distribution plate 6 is provided with an opening 10 for extracting, for example, the fluid medium 3, and the water wall pipes 7a and 7b positioned so as to sandwich the opening 10 have openings. It is necessary to bend so as to avoid the part 10. Therefore, the space between the water wall pipes 7a and 7b and the water wall pipes 7c and 7d located outside the water wall pipes 7a and 7b becomes narrow, and the air nozzle 4 cannot be installed on the membrane bar 8 between them.
[0005]
Further, even if the membrane 8 is wide, the air nozzle 4 cannot be installed in a portion close to the opening 10. Therefore, in the case as shown in FIG. 5, eight air nozzles cannot be installed in a portion surrounding the opening 10. Therefore, there occurs a problem that the flowing medium 3 in the vicinity of the opening 10 cannot flow normally.
[0006]
The present invention has been made in view of such a situation of the related art, and the purpose is to normally remove the fluid medium in the fluidized bed even in a place where an opening for extracting the fluid medium is installed in the air distribution plate. An object of the present invention is to provide a fluidized bed boiler that can be fluidized.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a first means is to arrange a plurality of air nozzles on an air distribution plate provided at a furnace bottom, and in a fluidized bed boiler for fluidizing a fluid medium by air from these air nozzles, A branch pipe having an air nozzle at an end portion is provided on an air supply pipe for sending air to the plurality of air nozzles. Thereby, the air nozzle can be arranged as a branch pipe branched from the air supply pipe also at a portion of the air distribution plate on the fluidized bed formation side where the air supply pipe cannot be arranged.
[0008]
According to a second aspect, in the first aspect, the branch pipe is supported at a lower end by a rocking member fixed to the air distribution plate. Thereby, the branch pipe can be firmly supported.
[0009]
The third means is that in the first or second means, the stand pipe to which the branch pipe is attached is inserted into the air distribution plate, and the upper and lower sides of the air distribution plate are fixed by welding. This makes it possible to improve the welding strength of the standpipe.
[0010]
A fourth means is characterized in that, in the first to third means, it is arranged near a portion surrounding an opening for extracting a fluid medium formed in the air distribution plate.
[0011]
A fifth means is the fourth means, wherein the air nozzle to which the branch pipe is attached is disposed so as to be located on the opening side.
[0012]
According to the fourth and fifth means, it is possible to attach the air nozzle also in the vicinity of the opening for extracting the fluid medium to which the air nozzle could not be attached conventionally, and the fluid medium can also be attached in the vicinity of the opening. Can flow normally.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same reference numerals will be given to the respective portions which can be regarded as equivalent to the above-described fluidized-bed boiler of the conventional example, and duplicate description will be omitted as appropriate. FIG. 1 is a plan view showing a part of an air distribution plate in a fluidized-bed boiler according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing a dispersion-type air nozzle arranged on the air distribution plate in FIG. FIG. 3 is a view cut along the line III-III in FIG. 2.
[0014]
As shown in FIG. 1, eight air nozzles 4 a positioned so as to surround the opening 10 for extracting the fluid medium 3 are arranged outside the air nozzles 4 with respect to the opening 10 of the air nozzle 4. It is provided in a form branched from. That is, in FIG. 1, the air nozzles 4 located near the opening 10 and on the left and right sides of the opening 10, respectively, are provided on the membrane bar 8 between the water wall pipes 7a and 7b. Six air nozzles 4 including a nozzle 4, an air nozzle 4 provided upright on a membrane bar 8 between water wall pipes 7a and 7c, and an air nozzle 4 provided upright on a membrane bar 8 between water wall pipes 7b and 7d; The air nozzle 4 erected on the membrane bar 8 between the water wall pipes 7c and 7e, the air nozzle 4 erected on the membrane bar 8 between the water wall pipes 7a and 7c, and the membrane between the water wall pipes 7d and 7f. A total of eight air nozzles 4 of the two air nozzles 4 erected on the bar 8 are provided with branched air nozzles 4a.
[0015]
That is, as shown in FIGS. 2 and 3, one end of a branch pipe 9 e bent in a substantially L-shape is provided at an intermediate portion of each of the stand pipes 9 b of the eight air nozzles 4. The nozzle heads 9a 'are attached to the upper ends of the branch pipes 9e, respectively. Similarly to the nozzle head 9a, the nozzle head 9a 'also has a plurality of openings in the circumferential direction for ejecting the air supplied from the air chamber 1. 9d is a lower welded portion where the lower end of the stand pipe 9b is fixedly welded to the emblem bar 8. Thereby, the welding strength of the mounting portion of the stand pipe 9b is improved. Numeral 11 denotes a swing stopper for preventing the branch pipe 9e from swinging, the upper end of which is fixed to the horizontal portion of the branch pipe 9e and the lower end of which is fixed to the membrane 8 by welding. This solves the problem of the strength of the stand pipe mounting portion caused by the branch type air nozzle 4. Although not shown, a damper may be provided at the branch between the stand pipe 9b and the branch pipe 9e so that the amount of air flowing through the branch pipe 9e can be adjusted.
[0016]
In this way, even if the position where the air nozzle should be installed is near the opening 10, the branch pipe 9e is connected to the stand pipe 9b of the air nozzle 4 located outside the opening, and the tip of the branch pipe 9e is connected. By positioning the side near the opening 10 and providing the nozzle head 9a 'at the tip thereof, it is possible to arrange the air nozzle also near the opening 10, thereby increasing the number of air nozzles. And the fluid medium 3 in the fluidized bed 5 can flow normally.
[0017]
【The invention's effect】
As described above, according to the present invention, since the branch pipe having the air nozzle at the tip is provided in the air supply pipe for feeding air to the plurality of air nozzles, the air dispersion plate is used to extract the fluid medium in the fluidized bed. The air nozzle can be provided in a place where it cannot be installed conventionally, such as an opening of the air nozzle, so that the number of air nozzles can be increased and the flowing medium can flow normally.
[Brief description of the drawings]
FIG. 1 is a plan view showing a part of an air distribution plate in a fluidized-bed boiler according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a dispersion type air nozzle arranged on the air distribution plate of FIG.
FIG. 3 is a view cut along a line III-III in FIG. 2;
FIG. 4 is a side view schematically showing an example of a conventional fluidized bed boiler.
FIG. 5 is a plan view showing a part of an air distribution plate in a conventional fluidized bed boiler.
FIG. 6 is a vertical sectional view showing an air nozzle arranged on the air distribution plate of FIG. 5;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Air chamber 2 Air 3 Fluid medium 4, 4a Air nozzle 5 Fluid chamber 6 Air distribution plate 7 Water wall tube 8 Membrane bar 9a, 9a 'Nozzle head 9b Stand pipe (air supply tube)
9c Upper weld 9d Lower weld 9e Branch pipe 10 Opening 11 Sway stopper

Claims (5)

In a fluidized-bed boiler in which a plurality of air nozzles are arranged on an air distribution plate provided at the furnace bottom and a fluidized medium is fluidized by air from these air nozzles,
A fluidized-bed boiler, wherein a branch pipe having an air nozzle is provided at an end of an air supply pipe for sending air to the plurality of air nozzles. The fluidized-bed boiler according to claim 1, wherein the lower end of the branch pipe is supported by an anti-sway member fixed to the air distribution plate. The fluidized-bed boiler according to claim 1 or 2, wherein the stand pipe to which the branch pipe is attached is inserted into the air distribution plate, and an upper side and a lower side of the air distribution plate are fixed by welding. . 4. The air nozzle to which the branch pipe is attached is disposed near a portion surrounding an opening for extracting a fluid medium formed in the air distribution plate. The fluidized-bed boiler according to Item. The fluidized-bed boiler according to claim 4, wherein the air nozzle to which the branch pipe is attached is arranged so as to be located on the opening side.

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