JPH0614721U - Nitrogen oxide low generation burner device - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] To reduce the generation of nitrogen oxides during combustion and to make the burner compact. [Structure] A lean fuel flame 4 to be formed on the same axis of the lean fuel mixture introducing portion 3 from the tip of the lean fuel introducing portion 3.
Of the fuel leaning premixed gas introduction portion is provided with a premixed gas swirl vane 6 on the outer periphery of the fuel supply portion 5 at the tip of the fuel lean premixed gas introduction portion. This is a nitrogen oxide low generation burner device in which a secondary air supply unit 7 is provided outside the lean premixed gas introduction unit. By forming the lean fuel combustion and the slow combustion stably on the burner central axis, nitrogen oxide is reduced and at the same time, the burner is made compact by forming it on the burner central axis.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a nitrogen oxide low generation burner device used in various heating furnaces and the like.

[0002]

[Prior art]

 The burner shown in FIG. 1 is the burner device shown in U.S. Pat. No. 4,496,306. In such a burner, a primary fuel supply part b is provided on the burner shaft of the air supply part a by retracting from the tip part, and a secondary fuel supply part c is provided outside the air supply part a. Is.

[0003]

【Problems to be solved】

 In the burner having such a configuration, in order to reduce the generation of nitrogen oxides, the position of the secondary fuel supply section c needs to be sufficiently away from the position where the primary combustion is performed, and the entire burner becomes large. In addition, there is a problem that secondary fuel is ejected at the outermost periphery of the burner, so if the mixing with the combustion gas containing excess air in the primary combustion is poor, soot adheres to the wall.

[0004]

[Means for solving problems]

 In order to solve the above-mentioned problems, the present invention provides a fuel lean premixed gas introduction portion coaxially with a length of about ½ or more of a lean fuel flame to be formed from the tip of the premixed gas introduction portion. The fuel supply section that protrudes by a certain amount is provided, and a premixed gas swirl vane is provided on the outer periphery of the fuel supply section at the tip of the fuel lean premixed gas introduction section. Is provided with a secondary air supply unit.

[0005]

[Action]

 When the lean fuel premix is ejected from the premixed air swirl vane, a stable lean fuel swirl flame with the swirl vane as the ignition source is formed while performing good mixing by swirling. On the other hand, at the center of the premixed gas swirl vane, there is located a fuel supply part which is protruded by a length of at least approximately ½ of the fuel lean swirl flame. Is being ejected, and this fuel has its roots clogged by the fuel-lean combustion flame, and while maintaining good flame holding, it is further mixed with the fuel-lean combustion flame and the secondary air supply It forms a diffusion slow combustion flame while mixing with the ambient air emanating from the section. Both the lean fuel flame and the slow diffusion combustion flame are located on the burner center axis.

[0006]

【Example】

 Reference numeral 1 is a furnace body, and 2 is a burner of the present invention attached to the furnace body 1. Reference numeral 3 denotes a fuel lean premixed gas introduction portion, and a fuel lean flame 4 to be formed coaxially with the fuel lean premixed gas introduction portion 3 from the tip of the fuel lean premixed gas introduction portion 3. The fuel supply unit 5 is provided so as to protrude by at least one length of about 2 minutes. A premixed gas swirl vane 6 is provided on the outer periphery of the fuel supply section 5 at the tip of the lean fuel premixed gas introduction section 3, and a secondary air supply section is provided outside the lean fuel premixed gas introduction section 3. 7 is provided.

When the lean fuel premixing is ejected from the premixed gas swirl vane 6, a stable lean fuel swirl flame 4 with the swirl vane 6 as an ignition source is formed while being mixed well by swirling. On the other hand, at the center of the premixed gas swirl vane 6, there is located a fuel supply unit 5 which is protruded by a length equal to or more than about half of the lean fuel swirl flame 4, and the fuel supply unit 5 is provided. 5, fuel is jetting out, and this fuel is in a state in which its root is entrapped by the fuel-lean combustion flame 4, and thereby the flame is satisfactorily maintained, and while mixing with the fuel-lean combustion flame 4, The diffusion slow combustion flame 8 is formed while mixing with the ambient air ejected from the secondary air supply unit 7. The lean fuel flame 4 and the diffusion slow combustion flame 8 are both located on the central axis of the burner. In this way, the generation of nitrogen oxides can be reduced by the lean fuel combustion flame 4 and the slow diffusion combustion flame 8 as shown in FIG. In particular, according to the present invention, the diffusion slow combustion flame 8 is in a state in which its root is surrounded by the lean combustion flame 4, so that the diffusion slow combustion progresses while being extremely stable. Moreover, while the lean burn flame 4 and the diffusion slow burn flame 8 are on the burner central axis, they simultaneously progress continuously and effectively reduce nitrogen oxides. The burner of the present invention was applied to an aluminum melting furnace, operated at a furnace temperature of 1300 ° C., and reduced to 38 ppm in NOx value ppm (O ₂ = 11%). It can be understood that this is extremely effective because the conventional burner has 63 ppm under the same conditions. .

[0008]

【The invention's effect】

 As described above, the present invention reduces nitrogen oxides by stably forming lean fuel combustion and slow diffusion combustion on the burner central axis, and at the same time achieves compaction of the burner by forming on the burner central axis. effective.

[Brief description of drawings]

FIG. 1 is an explanatory view of a conventional burner.

FIG. 2 is an explanatory view of a burner of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace body 2 Burner of the present invention 3 Fuel lean premixed gas introduction section 4 Fuel lean flame 5 Fuel supply section 6 Premixed gas swirl blade 7 Secondary air supply section 8 Slow diffusion combustion flame

Claims (1)

[Scope of utility model registration request] 1. A fuel projecting coaxially with a lean fuel mixture introducing portion from a tip of the lean fuel introducing portion by a length of about ½ or more of a lean fuel flame to be formed. A supply unit is provided, a premixed gas swirl vane is provided on the outer periphery of the fuel supply unit at the tip of the fuel lean premixed gas introduction unit, and secondary air is supplied to the outside of the fuel lean premixed gas introduction unit. Nitrogen oxide low generation burner device equipped with a section.