KR100231972B1 - Burner for reducing nox - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a nitrogen oxide (NOx) reduction type burner that maximizes the combustion air stage injection effect.

2. The technical problem to be solved by the invention

The conventional exhaust gas recirculation method or the two-stage combustion method in the furnace require additional installation of nitrogen oxide reduction facilities in the existing facilities, and thus, there is a problem in that an economic burden and a continuous burden on the equipment, maintenance, and maintenance are required.

3. Summary of Solution to Invention

According to the present invention, the air separation tube extends to the parallel part of the burner tile, and the end thereof is in the shape of an enlarged tube, and the first vane and the second vane are installed within the same radius. Resolved.

4. Important uses of the invention

By changing the internal structure of the burner, it is possible to reduce nitrogen oxide without additional equipment and at the same time reduce dust.

Description

Nitrogen oxide-reduced burner with maximized combustion air flow

The present invention relates to a nitrogen oxide (NOx) reduction type burner that maximizes the combustion air fractional influx effect, and more particularly to an industrial burner that can reduce the nitrogen oxide which is a pollutant produced by the combustion of fossil fuels in the combustion process, Primary vanes (1st. Vane) and secondary vanes (2nd. Vane) to control the combustion air are installed within the same radius so that the turnover and flow rate of the air flowing into each channel can be easily adjusted. Of the nitrogen oxides produced in the main combustion zone by expanding the primary air in the radial direction by expanding the end of the air separator separating the secondary air and extending it to the burner outlet. It promotes reduction reactions and complete combustion of incomplete combustion materials, and forms an initial flame zone with only secondary air to maintain low oxygen combustion conditions. By promoting the gasification of nitrogen components, the production of partial fuel nitrogen oxides (Fuel NOx) can be suppressed, and also the generation of thermal nitrogen oxides (Thermal NOx) can be suppressed.

In industrial boilers using fossil fuels, nitrogen oxides formed during the combustion process are the main cause of photochemical smog and their emissions are strictly regulated. Therefore, in the conversion of chemical energy into thermal energy by combustion, complete combustion is a basic requirement of the burner, and the reduction of nitrogen oxide without increasing the amount of fine dust is a very important item that determines the performance of the burner.

The nitrogen oxide reduction technique of the industrial burner used in the related art is excessive oxygen in a high temperature combustion zone to reduce the thermal NOx produced by the nitrogen contained in the combustion air reacting with the excess oxygen in a high temperature combustion atmosphere. Method of suppressing nitrogen reaction while maintaining fuel over-air insufficiency and incomplete combustion by injecting sufficient combustion air from the downstream side of the furnace where the furnace temperature is relatively low. This is mainly used.

To this end, a relatively low temperature combustion atmosphere is formed at the front of the burner to supply primary combustion air to suppress the production of nitrogen oxides, thereby maintaining fuel surplus and air shortages, and in order to completely burn the incomplete combustion products produced at this time. Combustion air was supplied. In order to form a fuel over-air deficiency in front of such a burner, there are two methods of exhaust gas recirculation and two-stage combustion in a furnace. The exhaust gas recirculation method mixes a part of the burned exhaust gas with combustion air. Refers to the method of combustion by flowing into the burner.

In addition, the two-stage combustion method in the furnace sends a part of combustion air directly to the hole installed on the burner to completely combust the unstable combustion gas in the burner area. These two techniques are nitrogen oxide reduction techniques requiring additional equipment. to be.

On the other hand, when a low nitrogen oxide burner using an aerodynamic method is used, the production of nitrogen oxide can be reduced by controlling the mixing characteristics of combustion air and fuel by splitly supplying combustion air from the burner.

The former two techniques have a high effect of reducing nitrogen oxides, but require additional installations of nitrogen oxide reduction facilities in existing facilities, and thus, economic burdens and continuous burdens on equipment, maintenance and maintenance are required. Therefore, in recent years, it is a trend to prefer the latter low nitrogen oxide burner which can reduce the nitrogen oxide without additional equipment only by the structural change by the aerodynamic consideration inside the burner.

The present invention, in order to actively respond to the above demands, by the aerodynamic consideration of the burner part to make the downstream combustion region in the excess air state to prevent the excessive increase of the unburned gas and dust generated during the combustion process and burner part initializing salt Promoting stabilization and low-oxygen combustion alleviates the peak temperature range of flames due to delayed combustion reactions. As a result, the formation of a low temperature combustion atmosphere suppresses the generation of nitrogen oxides in the excess fuel region near the burner, forms an excess air region in the wake of the flame, and promotes a reduction reaction of nitrogen oxides to nitrogen, thereby reducing nitrogen oxides The purpose of the present invention is to reduce the amount of nitrogen oxides while preventing the excessive increase of fractions while solving the disadvantages of the nitrogen oxide reduction burners.

The purpose of this is to extend the air separator to the parallel of the burner tile and to form the end of the enlarged tube so that the primary air blowing direction is directed toward the furnace wall surface, and the primary air and the secondary air are rotated and Easily control the amount of air with each swing vane, stabilize the initial salt by secondary air, and reduce the excess oxygen concentration needed to produce nitrogen oxide by low oxygen combustion of flame zone by diffusion effect of steel primary air. By suppressing the formation and dividing the flame, it is possible to realize the rapid cooling of the high-temperature flame surface and to suppress the generation of nitrogen oxides, and the unburned dust inevitably generated by the low oxygen combustion is caused by the combustion air concentrated in the wake of the flame zone. Complete combustion is achieved, and the combustion intermediates and the generated nitrogen oxides in unburned gas are converted into nitrogen. The original reaction up will be described in detail below through the drawings can bar, attached, which is achieved by the present invention so as to further reduce the nitrogen oxides.

1 is a cross-sectional view of the present invention.

2 is a flow and combustion field shape diagram according to the present invention.

3 is a temperature distribution characteristic diagram of the furnace of the present invention.

4 is a nitrogen oxide and dust emission characteristics of the present invention.

5 is a cross-sectional view of a conventional burner.

* Explanation of symbols for main parts of the drawings

1: 1st Bain 2: 2nd Bain

3: air separator 4: parallel part

5: enlarged tube 6: burner tile

7: fuel nozzle 8: flame base

9: primary vane drive shaft 10: secondary vane drive shaft

1 is a cross-sectional view of the present invention, the present invention is invented to reduce the dust and nitrogen oxides in the burner itself, the primary vane (1), secondary vanes (2), air separation vessel (3), parallel (4), enlarged tube (5), burner tile (6), fuel nozzle (7), flame gun (8), primary vane drive shaft (9), secondary vane drive shaft (10) It consists of.

Hereinafter, the operation of the present invention will be described in detail.

Figure 2 shows the flow and combustion field shape diagram according to the present invention.

In the burner to which the present invention is applied, the primary vane 1 and the secondary vane structure 2 of the conventional burner of FIG. 5 are positioned within the same radius as in FIG. 1, and the primary vane drive shaft 9 and the secondary vane are positioned. By adjusting the drive shaft 10 it is possible to easily adjust the amount of air passing through each vane and the turning degree by turning the vane angle. In particular, it is possible to control the amount of air passing through the secondary vanes (2) irrespective of the degree of rotation of the primary vanes (1) to enable the multi-stage inflow of combustion air for reducing nitrogen oxides.

In addition, in order to maximize the effect of concentrating the primary air passing through the primary vane (1) to the wake of the flame zone, a parallel portion (4) is installed at the end of the existing air separation vessel (3) to burner tile (6). Extending to the parallel portion and attaching the expansion tube (5) to mix the primary air and fuel from the rear end of the intermediate combustion region as shown in FIG. As a result, the oxygen concentration in the initial combustion zone and the intermediate combustion zone was lowered, thereby minimizing the surplus oxygen required to oxidize nitrogen in the air and nitrogen in the fuel, thereby suppressing the generation of nitrogen oxides.

In addition, the unburned components generated by low oxygen combustion are easily mixed with excessive oxygen concentrated in the complete combustion zone to completely burn them, thereby preventing the increase in the unburnt due to the reduction of nitrogen oxides, and the intermediate products generated in the intermediate combustion zone and the generated nitrogen oxides. As the reduction reaction proceeds, the nitrogen oxides are further reduced.

In order to prevent flame instability caused by low oxygen combustion, it was installed in the radius of the same vane as the primary vane (1) of the secondary vane (2), so that an appropriate amount was easily introduced into the initial combustion zone, and the oxygen concentration of the flame zone derived accordingly The increase was easily solved by strengthening the turnover at the secondary vanes (2). That is, the flame zone formed by the increase of the turning degree and the expansion tube (5) of the air separation vessel (3) increases the diameter more than the conventional burner while promoting low oxygen combustion, complete combustion in the wake of the flame zone, and reduction reaction of nitrogen oxide. As it is split, the radiant heat of the flame increases, so that the flame zone temperature can be lowered as shown in FIG. 3, which is also very effective in suppressing nitrogen oxide production.

The effect of the present invention is shown in FIG. 3 as compared with the conventional invention. In view of the flame temperature distribution along the furnace depth direction, the present invention has a gentle temperature distribution without local high temperature portion, and thus the flame temperature is increased. It was possible to suppress the production of thermal nitrogen oxides. In addition, as shown in the results of FIG. 4, the effect of reducing nitrogen oxides and increasing the amount of dust can reduce nitrogen oxides and dust at the same time as compared with the conventional burner.

In addition, since the appropriate turning degree according to the furnace shape can be adjusted by the primary vane drive shaft 9 and the secondary vane drive shaft 10, it can be easily applied to various furnace shapes, so that the combustion reliability can be improved and enhanced. There is.

Claims (2)

In the burner equipped with the burner tile 6, the fuel nozzle 7, the flame insulator 8, etc., the primary vane 1 and the secondary vane 2 are provided in the same radius, and the air separator 3 A nitrogen oxide (NOx) reduction burner that maximizes the combustion air stage influx effect, characterized in that configured to connect the parallel portion (4) and the expansion tube (5). The method of claim 1, wherein the primary vane (1) and the secondary vane (2) is added to the primary vane drive shaft (9) and the secondary vane drive shaft (10) to adjust the degree of rotation and the amount of air suitable for the furnace shape Nitrogen oxide (NOx) reduction burner that maximizes the effect of single-stage combustion air, characterized by the formation of a flame.

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