JPH0828813A - Low nox burner - Google Patents

Abstract

PURPOSE:To suppress generation of NOx by combining air rich combustion and fuel rich combustion together and make combustion stable by forming air rich flames and fuel rich flames adjacent to each other. CONSTITUTION:A burner 20 for air rich combustion, in which a primary air is superfluously sucked into a mixing pipe 24, and a burner 30 for fuel rich combustion, in which the primary air is limitedly sucked into a mixing pipe 34, are formed by subjecting outer side faces thereof to bulging making combustion surfaces 21, 31 as centers and bending the same. The both burners 20, 30 are joined with inner surfaces thereof back to back to make the combustion surfaces 21, 31 align on a top surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low NOx burner in which a nitrogen gas in exhaust gas is reduced by incorporating it into a forced combustion gas appliance in which combustion air is blown by a fan.

[0002]

2. Description of the Related Art Recently, in gas appliances for home use such as water heaters and bath kettles, a forced combustion type has been widely used in order to achieve miniaturization and high performance, and a plurality of steel plate gas burner bodies are arranged to form a combustion device. are doing. On the other hand, there is a demand for reducing nitrogen oxides (NOx) contained in the combustion exhaust gas of such gas appliances, and air-rich combustion in which air is excessively supplied and fuel-rich combustion in which gas is excessively supplied are combined as a whole. A means for reducing the combustion temperature and suppressing the generation of NOx is effective. Then, various gas burners aiming to reduce NOx are provided by the combination of such rich and lean combustion.

[0003]

However, the air-rich combustion in which the primary air is excessively supplied into the mixing tube and mixed with the gas, and the lean gas is discharged from the flame hole contributes to the decrease of the combustion temperature and suppresses NOx. However, there is a problem that combustion is not stable due to flame lift. Further, the conventional low NOx burner based on the combination of rich and lean combustion has a complicated structure and a large gas burner body, and in particular, household gas appliances are required to be downsized, and the installation space of the gas burner body is limited. The configuration is not preferred.

The present invention is intended to solve these problems, and is a low-NOx steel plate having a novel construction incorporated in a forced combustion gas appliance in which combustion air is blown by a fan.
A burner is provided to suppress the generation of NOx by combining air-rich combustion and fuel-rich combustion, and an air-rich flame and a fuel-rich flame are formed adjacently to stabilize combustion at the base of the flame. It is an object of the present invention to provide a low NOx burner that is manufactured in a small size.

[0005]

In order to achieve the above object, the low NOx burner of the present invention has a combustion surface as a center and an outer surface which is bent by bulging to suck excessive primary air into the mixing tube. A burner for air-rich combustion and a burner for fuel-rich combustion in which suction of primary air is restricted are formed in the mixing tube, both burners are joined back to back, and combustion surfaces are arranged on the upper surface. Is. The configuration of the present invention will be specifically described below with reference to the embodiments of the drawings.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings show an embodiment of the present invention in which a gas burner body (10) made of a steel plate is arranged at a predetermined interval and incorporated in a forced combustion gas appliance to construct a combustion device for heating a heat exchanger. In the drawings, the burner for air-rich combustion (20) and the burner for fuel-rich combustion (20) whose outer shapes are approximately the same are bulged by bulging and bending the outer side around the combustion surfaces (21), (31). And are formed. Then, the inner side surfaces of both burners (20) and (30) are back-to-back abutted against each other and the edges are folded and folded, so that both burners (20) and (3
0) are integrally joined to form a gas burner body.
Both burners (20), (30) have inlet openings (22), (3) which are suction ports for gas and air due to the bulging portion on the outer surface.
2) are opened side by side below the side of the gas burner body, and the throat portion (2) is continuously formed from the inlet openings (22) and (32).
3), (33), mixing pipe (2) for mixing gas and air
4) and (34) are formed, and mixing tubes (24) and (34) are formed.
Is bent upward, and combustion surfaces (21) and (31) are arranged side by side on the upper surface, and slit flame holes (25) and (35) are arranged in rows on the combustion surfaces (21) and (31). .

In this gas burner body, the throat portion (23) is arranged so that the air-rich combustion burner (20) sucks excessive primary air and the fuel-rich combustion burner (30) limits suction of the primary air. ) And (33) are set. And each inlet opening (22),
The gas nozzles are arranged opposite to (32), and the gas inputs to both burners (20) and (30) are set so that the air-rich combustion becomes the main combustion and the fuel-rich combustion becomes the sub-combustion.

Next, the combustion of the gas burner body thus constructed will be described. When the operation switch is turned on, the valve in the gas supply path is opened, and both gas mixing nozzles (24),
Gas is ejected into (34) and combustion air is blown by a fan to mix gas through the inlet openings (22) and (32).
4), (34) is sucked. Then, in the air-rich combustion burner (20), excess primary air is sucked from the primary air amount suitable for the gas type, the gas and the primary air are mixed in a lean gas state, and the lean gas is discharged from the slit flame hole (25). Are ejected to perform air-rich combustion, and an air-rich flame is formed on the combustion surface (21). On the other hand, in the fuel rich combustion burner (30), a smaller amount of primary air than the amount of primary air suitable for the gas type is sucked, the gas and the primary air are mixed in a rich gas state, and the rich air is discharged from the slit flame hole (35). The gas is ejected to perform fuel rich combustion, and a fuel rich flame is formed on the combustion surface (31). As a result, the air-rich flame and the fuel-rich flame are adjacent to each other to form a flame and burn.

[0009]

The characteristic effects of the present invention are as follows. An air-rich combustion burner (20) and a fuel-rich combustion burner (30) are formed, and both burners (2
0) and (30) are formed by joining the inner surfaces thereof back to back, and the air-rich combustion and the fuel-rich combustion are reliably performed, so that the combustion temperature can be kept low as a whole, and the generation of NOx can be suppressed. And the burning surface (21),
(31) is arranged on the upper surface, and the air-rich flame and the fuel-rich flame are formed adjacent to each other. Stability can be achieved.

Further, both burners (20) and (30) are joined back to back to be manufactured in a small size and in a thin shape, and the low NOx burners of the present invention can be arranged side by side to easily construct a combustion device, and the installation space is required. It is also allowed to design it small and arrange it densely to achieve high capacity, and in particular, it can be adapted to miniaturization, thinning and high capacity of household gas appliances.
When the low NOx burners of the present invention are arranged side by side to form a combustion device, air-rich combustion and fuel-rich combustion are performed in an alternating relationship, and it is possible to realize balanced combustion as a whole.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention.

FIG. 2 is a front view.

FIG. 3 is a rear view.

FIG. 4 is a plan view.

[Explanation of symbols]

 20 Air-rich combustion burner 21 Combustion surface 24 Mixing tube 30 Fuel-rich combustion burner 31 Combustion surface 34 Mixing tube

Claims (1)

[Claims] 1. A low NOx burner made of a steel plate to be incorporated in a forced combustion gas appliance for blowing combustion air by a fan, the outer surface of which is bulged around the combustion surfaces (21, 31). Bending, an air-rich combustion burner (20) in which the primary air is excessively sucked into the mixing pipe (24), and a fuel-rich combustion burner (30) in which the suction of the primary air is restricted into the mixing pipe (34). To form both burners (2
Low NO with 0) and (30) joined together with their inner surfaces back to back and combustion surfaces (21) and (31) arranged side by side.
x burner.