JPS5823052Y2 - Low nitrogen oxide burner for boilers - Google Patents

Description

[Detailed description of the invention] This invention has a wide range of applications, including industrial use as well as air conditioning for urban buildings, and can respond to stricter pollution regulations to prevent pollution in modern urban environments. In order to fully adapt to the gas supply format in urban areas where there are overwhelmingly many It is one of the sources of air pollution.

A low nitrogen oxide burner for boilers that is configured to reduce the amount of nitrogen oxides (hereinafter referred to as NOx) generated. A fuel gas supply mechanism having a nozzle at its tip for ejecting air is provided on the axis, and an air header is provided on the combustion chamber side surface for dispersing and supplying primary air into the combustion chamber toward the axis. and an air chamber provided with a plurality of combustion exhaust gas mixing pipes arranged at predetermined intervals in the circumferential direction while penetrating in the axial direction is externally fitted and fixed to the tip of the fuel gas supply mechanism 5. Furthermore, from the side opposite to the combustion chamber 2 with respect to the air chamber A, the exhaust gas mixing pipe 1...
Air nozzle 3 blows out secondary air towards...
A low nitrogen oxidation system for a boiler, which is configured to recirculate combustion exhaust gas into the combustion chamber 2 through the mixing pipe 1 by using secondary air ejected from these air nozzles 3. Regarding burners.

This type of burner has been used for a long time, for example, in the 1970s.
In such a conventional burner known from Japanese Patent No. 55232, the opening of the combustion exhaust gas mixing pipe facing the air nozzle is shaped along a plane perpendicular or substantially perpendicular to the burner axis. Therefore, when the combustion exhaust gas around the opening is sucked into the mixing pipe as secondary air is blown toward the mixing pipe by the air nozzle, the inflow angle of the combustion exhaust gas with respect to the opening is large. Therefore, the suction introduction efficiency is not very good, and therefore, the nitrogen oxides cannot be sufficiently reduced by circulating the combustion exhaust gas.

The present invention was developed in view of the above-mentioned circumstances, and its purpose is to improve the burner having the above-mentioned configuration so that it has extremely high combustion exhaust gas introduction efficiency, and to achieve even better NOx emissions. The objective is to achieve a reduction effect and to achieve this improvement with a configuration as simple as possible.

In order to achieve such an object, the low nitrogen oxide burner for a boiler according to the present invention has an opening of the flue gas mixing pipe facing the air nozzle formed with a surface that slopes toward the combustion chamber as the distance from the burner axis increases. It has the characteristic of being structured in a shape that follows.

According to the characteristic configuration described above, the opening of the combustion exhaust gas mixing pipe opens at an angle toward the outer periphery of the air chamber, and the opening area becomes larger than the cross-sectional area of the mixing pipe. Combined with this, it becomes possible to suction and introduce combustion exhaust gas with the secondary air jetting, and as a result, compared to the amount of combustion air jetted from the air nozzle, sufficient combustion exhaust gas can be sucked in and the combustion can be mixed into the
This makes it possible to further improve the effect of reducing nitrogen oxides through exhaust gas circulation.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

A fuel gas supply mechanism 5 equipped with a nozzle 5B at its tip that injects fuel gas into the combustion chamber 2 configured in a horizontal trapezoidal shape in a radial outward wave pattern with respect to the burner axis (not shown) is placed on the burner axis. At the same time, an air header 4 is provided on the surface on the combustion chamber 4 side for further dispersing and supplying air into the combustion chamber 2 toward the burner axis, and the air header 4 is provided on the surface on the combustion chamber 4 side, and extends around the periphery in a state penetrating in the axial direction. A feather-shaped air chamber A having a plurality of combustion exhaust gas mixing pipes 1 disposed at predetermined intervals in the direction is externally fitted and fixed to the tip of the fuel gas supply mechanism 5. Further, an air nozzle 3 is provided for jetting secondary air toward the exhaust gas mixing pipe 1 from the side opposite to the combustion chamber 2 with respect to the air chamber A, The low nitrogen optimized burner for a boiler is configured to recirculate the combustion exhaust gas into the combustion chamber 2 through the mixing pipes 1 by using the secondary air ejected from these air nozzles 3.

The air nozzle 3... is a combustion air supply port 6.
The air port 7 is provided in a protruding state on the front wall surface of the air port 7, and the combustion exhaust gas in the furnace is caused by the secondary air pressure ejected from each of these nozzles 3 toward the mixing pipe 1, as shown by the arrow. The mixture is drawn in and mixed into the mixing tube 1 and recirculated into the combustion chamber 2.

The air chamber A is connected to the tip of an air supply pipe 8 that extends toward the combustion chamber 2 and communicates with the air port 7 .

The opening of the combustion exhaust gas mixing pipe 1 facing the air nozzle 3 has a shape that follows a surface that slopes toward the combustion chamber 2 as the distance from the burner axis increases. It is configured.

With this configuration, the combustion exhaust gas around the opening is extremely efficiently introduced into the mixing pipe 1 as air is ejected from the air nozzle 3.

[Brief explanation of drawings]

The drawing shows a longitudinal sectional view of a low nitrogen oxide burner for a boiler, which is an embodiment of the present invention.

Claims (1)

[Scope of utility model registration request] The fuel gas is radially outwardly undulated from the burner axis into the combustion chamber 2.
A fuel gas supply mechanism 5 equipped with a nozzle 5B at its tip that spouts inward is provided on the axis, and an air header 4 for distributing and supplying primary air into the combustion chamber 2 toward the axis is provided on the axis. A plurality of combustion exhaust gas mixing pipes 1 are provided on the surface of the combustion chamber 4 and are arranged at predetermined intervals in the circumferential direction so as to penetrate in the axial direction.
An air chamber A comprising: is externally fitted and fixed to the tip of the fuel gas supply mechanism 5, and further, from the side opposite to the combustion chamber 2 with respect to the air chamber A, the exhaust gas mixing pipe 1... Air nozzles 3 are provided that eject secondary air toward the mixing pipe 1,
A low nitrogen oxide burner for a boiler, which is configured to recirculate the combustion exhaust gas into the combustion chamber 2 through the air nozzle 3 of the flue gas mixing pipe 1.
. . . A low nitrogen oxide burner for a boiler, characterized in that an opening portion facing the .