JPH08100904A - Gas burner - Google Patents

Abstract

PURPOSE: To suppress NOx , to increase the town down ratio, to reduce the vibration and the noise at the time of burning and to increase the O2 range. CONSTITUTION: A disc plate 20 is mounted at the end of a gas pipe 1, a blade type circular plate 22 with an air hole 25 is mounted at the rear, a primary gas nozzle 26 is provided and the front face of the plate 22, the outer diameter of the plate 20 is set slightly larger than the inner diameter of the cutout 23 of the plate 22, the mixture of the air with the gas is expedited, and the flame (a) is diffused to the periphery by the plate 20 to be brought into direct contact with a water wall thereby to lower the flame temperature, thereby suppressing the generation of NOx .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas burner used in various boilers, absorption chillers, etc., which has a low NO _x and a wide town down ratio, reduces vibration and noise, and has a wide O ₂ width. It is proposed for the purpose.

[0002]

2. Description of the Related Art In the case of various gas burners, reduction of NO _x is a proposition in order to prevent air pollution. Moreover, for the purpose of improving the usage characteristics, the town down ratio (the maximum and minimum width of the combustible gas amount) is expanded, noise and vibration are reduced,
The expansion of the O ₂ width is required. As a means for achieving these objects, in the case of a conventional gas burner, a split flame combustion or a lean combustion method is adopted, and any of these methods is a method of recirculating its own exhaust gas inside the furnace.

FIG. 6 shows an example of a gas burner adopting a lean burn method. 1 is a gas pipe, 2 is a draft tube, 3 is a wind box, 3a is an air supply port, 4 is a primary gas nozzle provided in the gas pipe 1, Reference numeral 5 is a secondary gas nozzle provided at the tip of the gas pipe 1, 6 is a burner cone attached between the tip of the gas pipe 1 and the draft tube 2, and the burner cone 6 is provided with a large number of dilution gas ejection holes 7. There is. 8 is by lot burner,
Reference numeral 9 is a flame rod for combustion confirmation. In the case of this conventional example, the combustion gas is supplied from the gas pipe 1 and a part thereof is ejected from the primary gas nozzle 4 into the draft tube 2,
It is mixed and diluted in the air supplied from the air port 3a,
Burner cone 6 from dilution gas injection hole 7 of burner cone 6
The flame a is formed at the tip of the draft tube 2 by being jetted inward and mixed with the gas jetted from the secondary gas nozzle 5.

[0004]

However, the above gas burner has the following drawbacks. a. When various combustion experiments were performed, in the graph shown in Fig. 7
As shown by, the maximum value of NO _X does not fall below 45 ppm, and even the minimum value does not fall below 39 ppm. b. Since the diluent gas is ejected toward the center by the burner cone 6, the flame a is long forward and does not diffuse. For this reason,
The towndown ratio is limited to around 3.5: 1. c. Vibration and noise during combustion are large. d. Since the angle of the burner cone 6 and the processing of the diluent gas ejection holes 7 are required to be highly precise, the manufacturing cost is high and the structure inside the burner is complicated. e. A large amount of O ₂ is emitted.

[0005]

The structure of the present invention proposed to solve the above problems is as follows. A circular plate having a diameter larger than that of the gas pipe was attached to the tip of the gas pipe, and a blade-shaped circular plate having a notch formed in the periphery was attached at a certain distance behind the circular plate, and the primary gas nozzle was attached to the above. The blade-shaped circular plate plate is provided close to the front, the blade-shaped circular plate plate is provided with an air hole, and the outer peripheral portion of the blade of the blade-shaped circular plate plate is fixed to the tip of the draft tube. A gas burner characterized in that the outer diameter of the plate is formed to be slightly larger than the inner diameter of the cutout portion of the blade-shaped circular plate plate.

[0006]

The combustion gas is supplied through the gas pipe, ejected from the primary gas nozzle to the outside, mixes with the air ejected from the air holes of the vane-shaped circular plate, and further mixes with the air supplied through the notch. Then, it is diluted and diffuses around while colliding with a circular plate to form a flame at the tip of the draft tube.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of a gas burner embodying the present invention, in which 1 is a gas pipe, 2 is a draft tube, and 3 is a draft tube.
Is a wind box, 3a is an air supply port, 20 is a circular plate attached to the tip of the gas pipe 1, 21 is a pilot gas nozzle, and 22 is a blade-shaped circular plate.
This circular plate plate 22 has a notch 2 of 30 degrees around it.
6 blades 24 are formed by forming 3 and are attached to the gas pipe 1 at a position of 50 m / m behind the circular plate 20, and the outer periphery of the blade 24 is the inner peripheral surface of the tip of the draft tube 2. It is fixed. In the case of the embodiment, the outer diameter of the circular plate 20 is 175 m / m, and the outer diameter of the blade-shaped circular plate plate 22 is 227 m / m. Reference numeral 25 is an air hole provided in the blade-shaped circular plate plate 22, 26 is a primary gas nozzle provided in the gas pipe 1, and the primary gas nozzle 26 is provided at a position as close as possible to the front surface of the blade-shaped circular plate plate 22. The diameter is 7.5 m /
m, the number is 12 in the circumferential direction.

In the case of the above-mentioned embodiment, the fuel gas supplied from the gas pipe 1 is jetted from the primary gas nozzle 26 to the front surface of the blade-shaped circular plate plate 22, and here is jetted from the air holes 25 of the blade-shaped circular plate plate 22. As well as mixing with the air coming in, it is further diluted with the air supplied from the notch 23, collides with the circular plate 20 and diffuses to the surroundings.
A diffusion flame a as shown in FIG.

[0009]

The effects of the present invention are as follows.

A. By setting the outer diameter of the circular plate to be larger than the inner diameter of the cutout part of the blade-shaped circular plate plate, the gas that is ejected from the primary gas nozzle and mixed with the air ejected from the air hole and still high in concentration is discharged from the cutout part. It further mixes with the outflowing air, which impinges on the circular plate and diffuses into the surroundings.
As a result, the flame because the temperature decreases in direct contact with the water wall of the furnace, it is possible to suppress the generation of NO _X. Fig. 3 is a graph showing the NO _x generation value.
It can be seen that it is suppressed to 5 ppm or less.

B. By providing the primary gas nozzle close to the front surface of the blade-shaped circular plate plate and providing the notch in the blade-shaped circular plate plate, the air and the primary gas are smoothly mixed, and the vibration and noise level is 20 to 20% higher than the conventional level. 7
It can be reduced by 0%.

C. Since the air and the primary gas are mixed smoothly, the O ₂ width is 100,000 kcal / h and 5.3.
%, And 8.7% at 500,000 kcal / h (FIGS. 4 and 5).

D. According to experiments, the combustion range is 500,000-10
It is stable without vibration up to 10,000 kcal / h, and thus the town down ratio can be improved to 5: 1 (FIGS. 3, 4, and 5).

E. Manufacturing cost is 7 ~ due to simple structure
It can be reduced by 15%.

[Brief description of drawings]

FIG. 1 is an explanatory view of a gas burner embodying the present invention.

FIG. 2 is an explanatory view of a circular plate and a blade-shaped circular plate plate attached to a gas pipe.

FIG. 3 is an explanatory diagram of NO _X values when the present invention is implemented.

FIG. 4 is a graph showing a good combustion range and a towndown ratio when the present invention is carried out.

FIG. 5 is a graph showing an O ₂ width and a towndown ratio when the present invention is carried out.

FIG. 6 is an explanatory view of a conventional cone type lean burn gas burner.

FIG. 7: Conventional gas burner (marked with ◇) and burner of the present invention (□)
A graph showing the amount of NO _x generated in ().

[Explanation of symbols]

 1 Gas Pipe 2 Draft Tube 20 Circular Plate 22 Blade Type Circular Plate Plate 23 Notch 24 Blade 25 Air Hole 26 Primary Gas Nozzle

Claims (1)

[Claims] 1. A circular plate having a diameter larger than that of the gas pipe is attached to the tip of the gas pipe, and a blade-shaped circular plate plate having a notch in the periphery is attached at a certain distance behind the circular plate. The primary gas nozzle was installed close to the front of the blade-shaped circular plate plate, the air holes were provided in the blade-shaped circular plate plate, and the outer peripheral portion of the blade of the blade-shaped circular plate plate was fixed to the tip of the draft tube. The gas burner is characterized in that the outer diameter of the circular plate is formed to be slightly larger than the inner diameter of the cutout portion of the blade-shaped circular plate plate.