JPH06159627A - Low nox burner - Google Patents

Abstract

PURPOSE:To provide a low NOX burner in which occurrence of NOX can be restricted and it has a simple configuration capable of preventing a lifting of flame. CONSTITUTION:A combustion surface 20 having main flame holes arranged in row-is formed at an upper end, a fuel rich mixing pipe 13 and an air rich mixing pipe 15 are independently formed, suction of primary air is restricted at the fuel rich mixing pipe and an excessive amount of primary air is sucked into the air rich mixing pipe 1,5. The air rich mixing pipe 15 is communicated with the combustion surface 20, an expanded plate 25 expanding outwardly is connected to an upper end of a side plate 11. and the upper end is opened. Flame holding openings 26 are formed along both sleeves of the combustion surface, and a fuel rich mixing pipe 13 is communicated in a spacing formed by the side plate 11 and the expanding plate 25. In this way, occurrence of NOX is restricted through air rich combustion and lifting of flame is prevented by flame holding formed through fuel rich combustion.

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 nitrogen oxide (NOx) contained in the exhaust gas of a gas appliance is reduced.

[0002]

2. Description of the Related Art Generally, a household gas appliance such as a water heater or a bath cooker comprises a plurality of gas burner bodies made of steel plates arranged side by side to form a combustion apparatus, and the gas burner body is formed by joining edges of bulged side plates. Produced. Recently, it has been demanded to reduce NOx contained in the combustion exhaust gas of such gas appliances, and air-rich combustion in which air is excessively supplied is combined with fuel-rich combustion in which gas is excessively supplied to lower the overall combustion temperature. Therefore, a means for suppressing the generation of NOx is effective. Further, various gas burners aiming to reduce NOx are provided by combining 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, flame holding means is required to prevent the lift of the flame, and the structure is complicated and the gas burner body tends to be large. In particular, household gas appliances are required to be downsized, and the installation space for the gas burner body is limited. Therefore, a complicated configuration is not preferable.

An object of the present invention is to provide a low-NOx burner having a novel structure and solve these problems. By combining air-rich combustion and fuel-rich combustion, NOx generation is suppressed and air-rich combustion is performed. The present invention provides a low NOx burner that has a simple structure and is manufactured in a small size by stabilizing the main flame formed by the above by the flame holding formed by the fuel rich combustion to prevent the lift of the flame.

[0005]

In order to achieve the above-mentioned object, the low NOx burner of the present invention is formed by joining the edges of the bulged side plates and forming the combustion surface in which the main flame holes are arranged at the upper end. It is a low NOx burner, and the fuel-rich mixing pipe and the air-rich mixing pipe are independently formed, the suction of the primary air is limited to the fuel-rich mixing pipe, and the primary air is excessively sucked to the air-rich mixing pipe. To set. Then, the air-rich mixing pipe is connected to the combustion surface, the bulging plate that bulges outward is joined to the upper end of the side plate to open the upper end, and flame-holding openings are formed along both sleeves of the combustion surface. A fuel-rich mixing tube is connected in the space formed by the side plate and the bulging plate. Then, the side plates are formed symmetrically with respect to the combustion surface, and the side plates are bent and manufactured. 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 incorporated in a forced combustion type gas appliance for blowing combustion air by a fan to constitute a combustion device for heating a heat exchanger. It is a thing. The gas burner body (10) has a vertically long inlet opening (12) which is an inlet for gas and primary air.
Is formed on the side surface of the fuel-rich mixing pipe (13) and the air-rich mixing pipe (15) are vertically and independently formed, and both mixing pipes (13) and (15) are provided with an inlet opening (12).
It communicates with the upper and lower two stages. Fuel Rich Mixing Tube (1
The throat portion (14) of 3) is set to a small diameter, while the throat portion (16) of the air-rich mixing pipe (15) is set to a large diameter, and the suction of primary air is limited to the fuel-rich mixing pipe (13). The primary air is sucked into the air-rich mixing pipe (15) excessively. Then, gas nozzles for injecting the fuel gas into the both mixing pipes (13) and (15) are installed in the upper and lower two stages so as to face the throat portions (14) and (16).

A combustion surface (2) having slit holes (21) arranged in a row.
0) is formed on the upper end of the gas burner body (10), and the air-rich mixing pipe (15) is bent upward and communicates with the combustion surface (20). A bulging plate (25) bulging outward is joined to the upper end of the side plate (11), and the bulging plate (25) has an open upper end and is groove-shaped along both sleeves of the combustion surface (20). A flame-holding opening (26) is formed in the opening. Then, the fuel rich mixing pipe (13) bends upward, and the side plate (11)
And the bulging plate (25) communicate with each other at the end thereof.

The gas burner body (10) has a side plate (11) formed by symmetrically bulging a single steel plate around the combustion surface (20) to form a side plate (11), which is bent at the combustion surface (20) to form an edge portion. Fold it together and join. Then, two bulging plates (25) are welded to the upper end of the side plate (11) with the combustion surface (20) interposed therebetween.

Next, the gas burner body (10) having the above structure
The combustion will be described. When the operation switch is turned on, the valve in the gas supply path is opened, and both mixing pipes (1
When the gas is discharged into 3) and (15), a smaller amount of primary air than the primary air amount suitable for the gas species is sucked into the fuel rich mixing pipe (13), and the gas and the primary air are mixed in the rich gas state. Are mixed. On the other hand, excess air is sucked into the air-rich mixing pipe (15) in excess of the amount of primary air suitable for the gas species, and the gas and the primary air are mixed in a lean gas state. Then, a lean gas is ejected from the slit hole (21) to form a long-flame air-rich flame (30) on the combustion surface (20),
The rich gas is gently discharged from the flame holding opening (26) to form a short fuel rich flame (32).

[0010]

The characteristic effects of the present invention are as follows. An air-rich mixing pipe (15) set to suck the primary air excessively is provided with a combustion surface (2) in which main flame holes are arranged.
0), the lean gas is ejected from the main flame holes to form the air-rich flame (30) on the combustion surface (20), and the overall combustion temperature is kept low to suppress the generation of NOx contained in the combustion exhaust. be able to. Then, the fuel-rich mixing tube (13), which is formed so that the flame holding openings (26) are formed along both sleeves of the combustion surface (20) and the suction of the primary air is limited, is expanded with the side plate (11). Since it is configured to communicate with the inside of the space formed by the discharge plate (25), the combustion surface (2
A fuel rich flame (32) is formed in a state of sandwiching the air rich flame (30) formed in (0). Then, the air rich flame (30) has a fuel rich flame (3
It can be reinforced by 2) and rooted, preventing the lift of flame and realizing stable combustion.

Further, the edge portion of the side plate (11) is joined to form the combustion surface (20) at the upper end of the side plate (11), which is small and thin, and the low NOx burners of the present invention are arranged side by side to easily constitute a combustion device. It is also possible to design the installation space to be small and arrange them densely to achieve high performance, and in particular, it can be adapted to miniaturization and high performance of household gas appliances.

Further, the side plate (11) is formed symmetrically with respect to the combustion surface (20) and is bent and produced at the combustion surface (20). It has a practical function such that it is formed, there is no waste in plate cutting, and the manufacturing process is excellent in efficiency in a simple process.

[Brief description of drawings]

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

FIG. 2 is a plan view of an embodiment of the present invention.

FIG. 3 is a side view of the embodiment of the present invention.

[Explanation of symbols]

 11 Side Plates 13 Fuel Rich Mixing Tubes 15 Air Rich Mixing Tubes 20 Combustion Surfaces 25 Bulging Plates 26 Flame Retaining Openings

Claims (2)

[Claims] 1. A low NOx burner in which a swelled side plate (11) is joined at its edge and a combustion surface (20) in which main flame holes are arranged is formed at the upper end, which is a fuel rich mixing pipe (13). ) And air-rich mixing pipe (1
5) and the fuel-rich mixing tube (1
The suction of the primary air is restricted to 3), the primary air is sucked into the air-rich mixing pipe (15) excessively, the air-rich mixing pipe (15) is connected to the combustion surface (20), and The bulging plate (25) bulging in the direction is joined to the upper end of the side plate (11) to open the upper end, and the flame holding openings (26) are formed along both sleeves of the combustion surface (20) to form the side plate. A low NOx burner constituted by connecting a fuel rich mixing pipe (13) in a space defined by (11) and a bulging plate (25). 2. The low NOx burner according to claim 1, wherein side plates (11) are formed symmetrically with respect to the combustion surface (20) and bent at the combustion surface (20).