JPH0658507A - Combustion apparatus - Google Patents

Abstract

PURPOSE:To provide a combustion apparatus which effectually utilizes the whole of a burning furnace as a combustion field to form a spiral flame without superheating a burning furnace located in the vicinity of a nozzle. CONSTITUTION:Burners 3 are mounted on each of a front wall and a rear wall of a peripheral wall 2 constituting a burning furnace 1 into three stages four by four on each stage. Each spiral flame is formed with the pair of the two burners 3 each located on the front wall and the opposite rear wall. Such adjacent spiral flames are oppositely rotated. In each burner, the burning furnace is supplied with a fuel and air without undergoing diffusion mixture of the fuel and air, in which burning furnace the fuel and air are rendered to diffusion mixing in a process of spiral combustion for slow combustion with satisfactory use thereof as a combustion field.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device such as a boiler for electric power and a private power generator.

[0002]

2. Description of the Related Art A basic example of the prior art is shown in FIGS. In this example, the front wall 13 and the rear wall 14 each have four rows of three-stage total 1
Two burners 3, two in total, are installed in the furnace 1. Each of the burners 3 is attached to the front wall 13 and the rear wall 14 at symmetrical positions facing each other at right angles to the wall surface.

The structure of each burner 3 is shown in FIG. 9, in which a primary air nozzle 11 and a secondary air nozzle 12 are arranged around a fuel-air mixture (hereinafter referred to as mixture) nozzle 10. 11 and 12 are equipped with swirlers 15 and 16 for promoting mixing with the air-fuel mixture, respectively.

[0004]

In the conventional combustion apparatus, each burner 3 is independent as one combustion apparatus (burner), and each burner 3 mixes the air-fuel mixture with the primary air and the secondary air. , Designed to complete combustion. Therefore, the primary air and secondary air nozzles 11 and 12 of each burner 3
As described above, the swirling blades 15 and 16 are installed in the. Therefore, the combustion becomes short flame combustion near the furnace wall.

Although it is an excellent combustion system from the viewpoint of only combustion, the heat load in the vicinity of the burner becomes high and the reliability problem due to overheating of the furnace wall in the vicinity of the burner, slugging in the case of coal burning (melt adhesion of ash) The problem of NO, the problem of occurrence of NO _X , etc. accompany.

Further, since the entire furnace is not effectively used as a combustion field, the residence time of the combustion gas cannot be sufficiently secured, and an unburned component may increase (incomplete combustion). The present invention is
It is an object of the present invention to provide a combustion device that can perform stable combustion, excluding these problems found in conventional combustion devices.

[0007]

In order to solve the above-mentioned problems, the present invention has a plurality of burners installed on the front wall and the rear wall or both side walls of the furnace, and the burners are opposed to each other.
One pair of two burners forms one spiral flame (helical frame), and the pair of adjacent burners is attached to the furnace wall so as to form spiral flames in opposite rotation directions.

In order to form this spiral flame, in the present invention, a burner is attached to the furnace wall at an angle, or one to two burners facing each other are displaced and attached to the furnace wall at a substantially right angle.

In order to solve the above-mentioned problems, in the combustion apparatus according to the present invention, each of the burners is composed of a fuel nozzle and a primary air nozzle and a secondary air nozzle which are concentrically arranged around the fuel nozzle. In this configuration, a flow rate control device is provided at each of the air nozzle inlets.

Furthermore, according to the present invention, the burner has a primary air wind box communicated with each primary air nozzle and a secondary air wind box communicated with each secondary air nozzle of the burner, and both of them are provided. It also employs a burner that has an air volume control device that controls the amount of air flowing through the air box. The present invention also employs a configuration in which the above-described combustion device is arranged in a plurality of stages in the vertical direction of the furnace.

[0011]

In the combustion apparatus according to the present invention, the burner is attached to the furnace wall in a slanted manner, or the one-to-two burners facing each other are displaced, and the burner is attached to the furnace wall at a substantially right angle.
Multiple spiral burners are formed on the front wall and the rear wall of the furnace, or on opposite side walls, and one to two burners facing each other form a spiral flame. Adjacent pairs of burners generate spiral flames in opposite rotation directions. Formed and stable combustion is established.

Further, in the combustion apparatus according to the present invention, each burner is not equipped with a mechanism such as a swirl vane for promoting diffusion and mixing of fuel (mixture) and air for each burner, and these are supplied concentrically to the furnace. In the case of a furnace in which the air-fuel mixture and air are diffusely mixed in the process of spiral combustion in a smelting furnace, slow combustion is performed by fully utilizing the furnace as a combustion field.

Further, in the combustion apparatus according to the present invention, a primary air flow rate control device in which each burner is installed for each stage, a secondary air flow rate control device, and a primary air nozzle and a secondary air nozzle of each burner are provided. With the one having the provided flow rate control device, a spiral flame adapted to the size of the furnace can be stably established by adjusting these.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the embodiments shown in FIGS. 1 to 6, parts corresponding to those of the conventional device shown in FIGS. 7 to 9 are designated by the same reference numerals. 1 to 6, each of the front wall 13 and the rear wall 14 of the peripheral wall 2 forming the furnace is equipped with four rows of three-stage burners 3.

FIGS. 2 and 3 are plan views showing the arrangement of eight burners 3 in 4 rows and 4 rows in each stage.
It is shown that one burner forms four spiral flames and one burner 3 forms four spiral flames.

In the example of FIG. 2, the burners 3 of each stage are installed in the same plane, and the mounting positions are opposite to each other on the front and rear walls. The charging direction of is set at an angle at which four spiral flames are stably established. This mounting angle is selected so that the spiral flame has an optimum shape and size for the furnace cross-sectional shape.

Further, in the example of FIG. 3, the burners 3 are mounted at right angles to the front wall 13 and the rear wall 14 of the furnace, but the pair of opposing burners 3 are not opposed to each other, but a predetermined spiral flame is easily formed. Are installed with a gap between them and installed in a relationship that does not hinder the formation of adjacent spiral flames.

FIG. 4 shows the positional relationship between the furnace and the air passage. In FIG. 4, the combustion air supplied via an air preheater (not shown) is supplied via the main air passage 4 to the wind boxes arranged in front of and behind the furnace 1. The air box is divided into a primary air chamber 5 and a secondary air chamber 6, and each of the air chambers 5 and 6 is divided into burner stages.

Air volume control devices 7 and 8 are installed at the inlets of the air chambers 5 and 6, respectively, so that the primary air amount and the secondary air amount can be controlled for each stage. Each burner 3 is attached to the wind box. The basic structure of the burner 3 mounted at a right angle to the furnace wall 1 is shown in FIG.

The air-fuel mixture supplied from the air-fuel mixture supply pipe 9 is introduced into the furnace 1 through the fuel nozzle (or air-fuel mixture nozzle) 10.
The secondary air nozzles 11 and the secondary air nozzles 12 are concentrically arranged, and an annular air volume adjusting device (ring damper) is attached to each inlet (primary air adjusting ring damper 17, secondary air). Adjustment ring damper 18).

Reference numeral 13 denotes the front wall of the furnace, but the same applies to the rear wall 14. In the conventional burner (FIG. 9), swirl vanes 15 and 16 are installed in the primary air nozzle and the secondary air nozzle, respectively, and the air-fuel mixture and the primary air at the nozzle outlet of each burner,
Although the structure is such that secondary air is mixed, in this burner, the nozzle is at the nozzle outlet so that the fuel and air have a certain momentum in a certain direction so as to form a stable spiral flame in the furnace. It has a function to throw in without mixing.

10 and 11 show the combustion state (flow of combustion flame) in the furnace by the conventional burner and the combustion apparatus of the present invention. In the conventional combustion system, the flame formed by the burner of the furnace wall collides with the central surface of the furnace and becomes a combustion gas flow that rises along the central surface, but with the combustion apparatus of the present invention, as shown in FIG. Multiple spiral flames (one spiral flame for each burner pair) are formed and the flame fills the furnace, and the furnace functions more effectively as a combustion field.

Although the combustion apparatus according to the present invention has been specifically described above based on the illustrated embodiments, it goes without saying that the present invention is not limited to these embodiments and various modifications are possible within the scope of the present invention. May be added.

[0024]

EFFECTS OF THE INVENTION According to the combustion apparatus of the present invention, one spiral flame is formed in the furnace by the opposed one-to-two burners installed on the front and rear walls or both side walls. Accordingly, a plurality of small-sized spiral flames can be formed in the furnace, and the furnace can function as a combustion field more effectively. Therefore, the combustion reaction in the furnace can be slowly and uniformly performed.

Therefore, the heat load distribution in the furnace becomes uniform and no local high heat load is generated. Therefore, NO _X generation is suppressed,
The reliability against burnout of the furnace wall is improved, and the problem of slugging due to ash melting can be prevented.

Further, according to the present invention, since a stable spiral flame is established, stable combustion is maintained and the operation reliability is improved as compared with the conventional independent combustion method for each burner. Further, according to the present invention, since a long flame pass and a longer furnace residence time are possible, diffusion and mixing of fuel and air become complete, and it becomes easy to perform complete combustion at a lower air ratio, so that the boiler Thermal efficiency is improved.

Further, according to the combustion apparatus of the present invention, the primary air amount and the secondary air amount are adjusted for each burner stage and for each individual burner, so that the burner can be properly adjusted depending on the furnace shape, boiler load, and fuel property. A stable spiral flame can be established.

[Brief description of drawings]

FIG. 1 is a perspective view showing installation of a burner in a furnace according to an embodiment of the present invention.

FIG. 2 is a plan view showing a furnace plane and a burner attached state in the first embodiment of the present invention.

FIG. 3 is a plan view showing a furnace plane and a burner attached state in a second embodiment of the present invention.

FIG. 4 is a plan view showing a relational diagram of a furnace, an air duct, and a wind box in the combustion apparatus according to the present invention.

FIG. 5 is a sectional view showing a burner structure in a combustion apparatus according to the present invention.

FIG. 6 is a front view showing a burner nozzle structure in a combustion apparatus according to the present invention.

FIG. 7 is a plan view showing a furnace plane and a burner position by a conventional combustion device.

FIG. 8 is a side view showing a furnace front wall and a burner position by a conventional combustion device.

FIG. 9 is a sectional view of a burner nozzle according to a conventional combustion device.

FIG. 10 is a side view showing a combustion state in a furnace by a conventional combustion device.

FIG. 11 is a side view showing a combustion state in a furnace by the combustion apparatus according to the present invention.

Claims (6)

[Claims] 1. A front wall and a rear wall of a furnace, or a plurality of burners respectively installed on both side walls, the burner forming one spiral flame with one to two burners facing each other, and adjacent burners. A combustor in which a pair of burners are attached to a furnace wall so as to form spiral flames in mutually opposite rotation directions. 2. The combustion apparatus according to claim 1, wherein the burner is attached to the furnace wall in an inclined manner. 3. The combustion apparatus according to claim 1, wherein the pair of paired burners facing each other are displaced from each other and are attached to the furnace wall at a substantially right angle. 4. Each of the burners is composed of a fuel nozzle and a primary air nozzle and a secondary air nozzle which are concentrically arranged around the fuel nozzle, and a flow rate control device is provided at each of the air nozzle inlets. The combustion device according to claim 1, wherein the combustion device is provided. 5. A primary air wind box communicated with each primary air nozzle of the burner and a secondary air wind box communicated with each secondary air nozzle of the burner, and both flow boxes flow. The combustion apparatus according to claim 4, further comprising a flow rate control device that controls an air amount. 6. The combustion device according to claim 1, wherein the combustion device is arranged in a plurality of stages in the vertical direction.