KR19980040512U - Air two-stage combustion gas burner with primary communication - Google Patents

Abstract

The present invention is to extend the primary combustion zone to extend the combustion gas in the primary combustion zone by addressing the heat-resistant primary communication to the draft pipe from which the primary air and fuel are ejected, so that the generation amount of nitrogen oxides can be greatly reduced. A two-stage combustion gas burner equipped with a primary combustion communication system. An air two-stage combustion gas burner that splits and sprays combustion air into primary air and secondary air, and is provided in the outer periphery of the fuel supply pipe at the center of the burner. It is designed to have a primary combustion station and a secondary combustion station by attaching primary combustion communication to the end of the fuel pipe or to the outer periphery of the fuel supply pipe with primary and secondary air bulkheads.

Description

Air two-stage combustion gas burner with primary communication

The present invention relates to an air two-stage combustion gas burner equipped with a primary combustion communication, and in particular, by installing a heat-resistant primary communication connection to a draft pipe through which primary air and fuel are ejected, the primary combustion region is expanded to burn the combustion in the primary combustion region. The gas stay time is extended to reduce the amount of nitrogen oxide generated extremely.

In general, low-nitrogen oxide burners are widely used in combustion equipment for direct heating such as furnaces or boilers to reduce the amount of nitrogen oxides generated during combustion, and air two stage combustion burners are the mainstream.

Air two-stage combustion burner supplies the air required for combustion in two stages within the burner, and adjusts the ratio of primary and secondary air by adjusting the position of the fold.

Therefore, the first stage is supplied with 20 to 70% of the amount of air required to achieve two effects: inhibition of nitrogen oxide generation due to lack of oxygen and inhibition of nitrogen oxide generation due to lower combustion temperature. It is a way to burn completely.

As an example, Korean Utility Model Registration No. 66685 describes the characteristics of a two-stage combustion gas burner and the structure and characteristics of a conventional conventional two-stage combustion gas burner.

1 is a cross-sectional configuration diagram of a conventional two-stage combustion gas burner.

Referring to FIG. 1, the air supply port 10 is divided into a primary air passage 11 and a secondary air passage 12 by a side surface 15, and is supplied from the primary air passage 11. The fuel supply pipe 16 is installed in the center of the burner to which the air is injected.

The primary air is injected into the annular space between the fuel supply pipe 16 and the draw pipe 18. The air introduced into the secondary air passage 12 is sprayed through the secondary air nozzle 14. The primary air and the fuel are mixed in the draw 13 to generate primary combustion, and the fuel incompletely burned due to the lack of air is completely burned by the secondary air injected from the secondary air nozzle 14.

The results of theoretical computer simulations using nitrogen oxide production rate equations to predict the production of nitrogen oxides showed that the final nitrogen oxides were changed according to the change of filling time in the primary combustion zone during the combustion of air two stage burners. Emissions have been shown to change, and longer stays in the primary combustion zone have been shown to be effective in reducing NOx emissions.

This is because the longer the residence time in the primary combustion zone, the slower the combustion reaction with the secondary air is. Therefore, it can be seen that the expansion of the primary combustion zone will be useful for the reduction of nitrogen oxides.

However, in the case of the conventional air two-stage burner, as shown in FIG. 2, when the structure of the burner is determined, the primary combustion station 21 and the secondary combustion station 22 are determined in advance according to the burner structure. Therefore, the primary combustion zone 21 has a disadvantage in that it cannot extend the size (or primary combustion time). Therefore, the conventional air two-stage injection burner as shown in FIG. 1 is 40% or more nitrogen oxide compared to the one-stage combustion burner. Reduction has a difficult problem.

The present invention has been invented to solve the above problems in view of the above problems, and an object of the present invention is to provide an air two-stage combustion gas burner equipped with a primary combustion communication that can greatly reduce the amount of nitrogen oxides generated.

In order to achieve the above object, a feature of the present invention is an air two-stage combustion type gas burner that splits and splits combustion air into primary air and secondary air, and the primary and secondary air bulkheads at the outer periphery of the fuel supply pipe at the center of the burner. It is designed to have a primary combustion station and a secondary combustion station by installing primary combustion communication in connection with

1 is a cross-sectional configuration of a conventional air two-stage combustion gas burner,

Figure 2 is a state diagram showing the air / fuel mixing situation of the conventional air two-stage burner,

3 is a cross-sectional view of the air two-stage combustion gas burner according to the present invention,

4 is a state diagram showing a mixed state of air / fuel of the air two-stage combustion burner of the present invention,

5 is a graph showing the tendency of nitrogen oxide production according to the change in the primary combustion length of the two-stage combustion gas burner of the present invention.

* Description of the symbols for the main parts of the drawings *

10: air supply port 11: primary air passage

12: secondary air passage 13: drip

14: secondary air nozzle 16: fuel supply pipe

18: draft pipe 19: 1st and 2nd air bulkhead

20: 1st communication 21: 1st combustion station

22: secondary combustion station

Figure 3 of the present invention is a cross-sectional view of the air two-stage combustion burner according to the present invention, Figure 4 is a state diagram showing the air / fuel mixing situation of the burner of the present invention, Figure 5 is the first combustion communication length change of the minute design burner A graph showing the trend of nitrogen oxide formation.

The air two-stage combustion type gas burner of the present invention is attached to the draw pipe 18 of the conventional burner and is equipped with a heat resistant primary combustion communication 20. The primary combustion communication 20 may be connected to the primary and secondary air partitions 19 instead of the drop pipe 18. When the independent primary combustion cylinder 20 is installed as described above, the secondary combustion speed can be delayed by blocking direct contact between secondary air and unburned fuel at the burner discharge port. Can be reduced (see also the air / fuel mixture situation in FIG. 4).

Figure 5 shows the tendency of nitrogen oxides according to the change in the primary combustion length of the air two-stage burner of the present invention, the combustion capacity 200,000 by using a coke oven gas of 4,400 Kcal / Nm ³ calorific value generated in steel mills This is the result of experiment on burner of Kcal / hr.

The furnace temperature of the experiment furnace was maintained at 1,200 ℃. In FIG. 5, the burner installed with a 0.4 m length primary combustion cylinder can reduce additional nitrogen oxide by about 20% compared to a conventional air two-stage burner without the primary combustion cylinder, and has a length of the primary combustion cylinder. It can be seen that the longer the length of the nitrogen oxide can be reduced, the longer the length of the primary combustion cylinder, the higher the nitrogen oxide reduction rate increases.

This reduction of nitrogen oxides is the result of verifying the relationship between the nitrogen oxide production theoretically described above and the residence time of the primary combustion.

Primary communication communication 20 of the present invention may have a variety of installation methods and forms, since the primary communication communication 20 of Figure 3 shows only the basic form as an example, the present invention is a primary communication and other forms of It basically includes the installation method.

The material of the primary combustion tube 20 is not limited to heat-resistant steel, heat-resistant fiber sintered body, ceramics such as silica or alumina, etc., which ensure heat resistance, and an appropriate material may be used according to the temperature conditions of the combustion furnace in which the burner is used.

Even in the form of primary combustion communication 20, a reduction tube, expansion tube, horizontal tube, etc. can be used, and includes a porous tube for early combustion of some unburned fuel.

The gas burner of the present invention as described above has the effect of minimizing the amount of nitrogen oxides generated in the air two-stage combustion gas burner by providing independent primary combustion communication at the end of the draw pipe.

Claims (1)

In the air two-stage combustion type gas burner that splits and sprays combustion air into primary air and secondary air, By connecting the first and second air bulkheads 19 to the end of the draw pipe 18 installed at the outer periphery of the fuel supply pipe 16 at the center of the burner or to the outer periphery of the fuel supply pipe 16, An air two-stage combustion gas burner equipped with a primary combustion communication, characterized in that it has a secondary combustion station (21) and a secondary combustion station (22).