JPH09159122A - Premixing gas burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain perfect combustion by improving the flame holding performance and promoting the mixing of the flow of gas and air for burning in a ceramic kiln. SOLUTION: In a premixing gas burner mixed in advance that comprises a gas supplying pipe 2, with which the edge of the center axis of a burning air flow path 1 is shut and at just before the end of the edge, gas nozzles 3 are formed vertically to the center axis and the flame holding plate 4, on the front side of which edge part, burning air nozzles of the same number with the burning gas nozzles are formed, and air nozzle chambers 5 that protrudes beyond the gas nozzles 3 and the nozzles 4a that do not protrude are arranged alternatively as the burning air nozzles of the flame holding plate 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a premixed gas burner for use in a furnace for a ceramic industry, etc., which promotes the mixing of a gas stream and a combustion air stream while having high flame holding performance, and achieves complete combustion. Related to mixed gas burners.

[0002]

2. Description of the Related Art A conventional premixed gas burner has a structure in which fuel gas and combustion air are completely burned.
No. 73, a premixed gas burner in which a plurality of combustion air jets around the fuel gas jet flow path are long and protrudingly arranged and non-projecting jets are alternately arranged.
Japanese Patent No. 30482 discloses a combustion device in which a secondary air supply cylinder is projected forward from a gas fuel ejection end so that a gas ejection hole has a certain angle so that a gas fuel flow impinges on the secondary air supply cylinder.

[0003]

In the former premix burner, the air ejected from the protruding jet port and the air jetted from the non-projecting jet port only mix with the fuel gas at a position separated in the jetting direction. In the latter combustion device, the gas flow ejected from the gas ejection holes collides with the secondary air supply pipe at an angle, and most of the gas flows upward along the secondary air supply tube and is attracted to the secondary air flow. Just flowing in parallel, gas and air cannot be mixed sufficiently, resulting in slow combustion,
Soot was apt to be generated, and the flame burned and the flame extended for a long time, so that it was not easy to use as a premix burner for the ceramic industry.

According to the present invention, a gas flow ejected from a gas ejection hole of a gas supply pipe collides with a peripheral wall of a protruding air nozzle cylinder so as not to directly collide with an air flow, and a gas flow from an ejection port which does not project directly. It is an object of the present invention to provide a premixed gas burner which can improve the flame holding performance and effectively promote the mixing of air and gas, separately from a part to be mixed by collision.

[0005]

According to a first aspect of the present invention, there is provided a premixed gas burner in which a tip is closed at an axial center of a combustion air flow path 1 and a plurality of the peripheral surfaces immediately before the tip are perpendicular to the axial center. In the premixed gas burner in which the gas supply pipe 2 provided with the gas ejection holes 3 is provided and the flame holding plate 4 provided with the same number of combustion air ejection ports as the gas ejection holes at a position before the tip end, As a plurality of combustion air outlets of the plate 4, air nozzle tubes 5 protruding beyond the gas outlets 3 and jet outlets 4a which do not protrude are alternately arranged in the circumferential direction, so that the gas flow of the gas outlets is reduced. The gas nozzle is provided so as to be ejected immediately before the ejection port 4a where a part does not project, and a part of the gas flow collides with the protruding peripheral wall of the air nozzle cylinder 5.

According to the second aspect of the present invention, the protruding air nozzle cylinder 5
The distance L between the peripheral wall and the gas ejection hole 3 is 2 mm to 5 mm.
Is provided in the range.

According to a third aspect of the present invention, a primary combustion cylinder 10 is provided with a secondary air flow path 11 outside a combustion air flow path 1,
The combustion air is divided into primary air and secondary air, and the excess air ratio in the primary combustion is partially burned in the range of 0.5 to 0.8, and then the secondary air is completely burned.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a gas introduction head 7 is provided on one side of an air introduction head 6, a gas supply pipe 2 is connected to the gas introduction head 7, and a combustion cylinder 12 is provided on the other side of the air introduction head 6. In the premixed gas burner to which the gas supply pipe 2 is attached, the distal end of the gas supply pipe 2 is closed, and a plurality of gas ejection holes 3 are formed at a position immediately before the distal end in a circumferential direction and perpendicularly to the axis, and are maintained at a position in front of the gas supply hole. A flame plate 4 is provided, and an air nozzle cylinder 5 protruding beyond the gas ejection hole 3 and an ejection port 4a not protruding at a position crossing the center line of the gas ejection hole are alternately arranged on the flame holding plate 4 in the circumferential direction. To be provided. The distance L between the gas ejection hole 3 and the air nozzle cylinder 5 is in a range of 2 mm to 5 mm. A primary combustion tube 10 is provided in the combustion air flow path 1 in the air introduction head 6.
The primary combustion cylinder 10 faces a secondary combustion chamber 12 a of a combustion cylinder 12 connected to the air introduction head 6. In addition, the jet port 5a of the air nozzle cylinder 5 of the flame holding plate 4 and the jet port 4a which does not protrude.
The air-rich portion and the gas-rich portion can be arbitrarily changed by changing the area ratio of the air-rich portion.

As shown in FIGS. 4 and 5, a part of the gas ejected from the gas ejection hole 3 collides with the peripheral wall of the protruding air nozzle cylinder 5 and is diverted to the right and left, and the gas flows to the peripheral wall. Along with the surrounding air to generate a flame a. Further, by colliding with the cylinder surface, a spiral recirculation region is formed behind the cylinder to generate a flame b. This flame has a very excellent flame holding property and becomes a continuous ignition source, among which it protrudes. When the distance L between the peripheral wall of the air nozzle cylinder 5 and the gas ejection hole 3 is in the range of 2 to 5 mm, the strongest flame holding performance can be provided.

Further, the air flow from the air outlet which does not protrude, and the jet gas flow intersect and collide with each other at that location and mix. In this case, although the flame holding ability is low because the mixing is very good, the flame generated by colliding with the peripheral wall of the protruding air nozzle cylinder becomes a continuous ignition source, and as a result, the flame c is also generated here. As a result, combustion can be promoted in the primary combustion chamber even with an air amount less than the theoretical air amount. FIG.
FIG. 5 and FIG. 5 show the shape of a flame in low combustion, and the same principle is used in high combustion.

In the primary combustion, an excess air ratio of 0.5 to
In the range of 0.8, the partially burned partial combustion gas containing a large amount of CO and H ₂ is subjected to the secondary combustion in the combustion cylinder 12 by the secondary air supplied from the secondary air flow path on the outer periphery of the primary combustion cylinder. Room 1
After the start of the secondary combustion in 2a, the combustion is completed in a very short time, and the reaction stops before the time when NOx is generated. Therefore, the complete combustion is executed while the NOx is low. it can.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the drawings. 1 to 3, reference numeral 6 denotes an air introduction head having an air introduction port 8, reference numeral 7 denotes a gas introduction head having a gas introduction port 9. The air introduction head 6 is attached to the gas introduction head 7. A gas supply pipe 2 is connected to the gas introduction head 7 at the axis of the combustion air flow path 1. The front end of the gas supply pipe 2 is closed, a plurality of gas ejection holes 3 are formed in the position immediately before the front end in the circumferential direction and perpendicularly to the axis, and a disc-shaped flame holding plate is provided in the front position. 4 are integrally formed, and the flame holding plate 4 is provided with the same number of combustion air ejection ports as the gas ejection holes 3.

There are two types of combustion air outlets of the flame holding plate 4, and air nozzle cylinders 5 protruding beyond the gas outlets 3 and non-projecting outlets 4a are arranged alternately in the circumferential direction. The air nozzle cylinder 5 is formed integrally with the flame holding plate 4,
An ejection port 5 a is opened ahead of the gas ejection hole 3. The center line of the gas outlet 3 and the center line of the combustion air outlets 4a, 5a are arranged so as to intersect with each other, and the gas flow jetting vertically from the gas outlet 3 in the circumferential direction is applied to the peripheral wall of the air nozzle tube 5. It is designed to directly collide with the air flow of the jet port 4a which does not collide and does not project.

Reference numeral 10 denotes a primary combustion cylinder made of metal, which is provided with a secondary air flow path 11 around the inside of the air introduction head 6, and the combustion cylinder 1 having the primary combustion cylinder 10 connected to the air introduction head 6.
2 facing the inside of the secondary combustion chamber 12a. The combustion tube 12 is a refractory burner tile, but is not limited thereto.

Reference numeral 13 denotes a nozzle body provided with a secondary air ejection hole 14 provided between the air introduction head 6 and the combustion cylinder 12 to provide a secondary air flow path 11 between the combustion cylinder 12 and the primary combustion cylinder 10. Secondary air is blown out. 15 is a hole for mounting a spark plug,
Reference numeral 16 is a flame detection hole.

[0016]

According to the premixed gas burner of the first aspect of the present invention, the gas flow ejected vertically in the circumferential direction from the gas ejection hole of the gas supply pipe protrudes from the gas ejection hole of the gas supply pipe in either case of low combustion or high combustion. It collides with the peripheral wall of the air nozzle cylinder, spreads along the cylindrical surface, comes into contact with the surrounding air, generates a flat flame, and generates a spiral recirculation area behind the cylinder to generate a flame,
This flame is very flame-retardant and becomes a continuous ignition source. On the other hand, the air from the air outlet which does not protrude and the jetted gas directly collide and mix with each other, and the flame generated by colliding with the peripheral wall of the nozzle cylinder also generates a flame here. Since it is possible to simultaneously promote the effective mixing of air and gas, unlike the prior art, a soot-free, short flame and blue flame combustion can be obtained, and higher stable combustion characteristics can be obtained.

If the distance between the air nozzle cylinder and the gas ejection hole is set to 2 mm to 5 mm, the gas flow from the gas ejection hole surely collides with the peripheral wall to divide the gas precisely. A rich zone can be formed and a recirculation zone can be created to provide particularly strong flame holding performance.

According to the third aspect of the present invention, the combustion air is divided into the primary air and the secondary air, and the combustion is performed in two stages so that the combustion can be completely completed quickly. It can be suppressed by the burner itself without adding.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a premixed gas burner of the present invention.

FIG. 2 is a side view of a gas supply pipe.

FIG. 3 is a sectional view taken along line XX of FIG. 2;

FIG. 4 is an explanatory view showing a flame in low combustion in FIG. 2;

FIG. 5 is an explanatory view showing a flame in low combustion in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion air flow path 2 Gas supply pipe 3 Gas ejection hole 4 Flame holding plate 4a Non-projecting ejection port 5 Air nozzle cylinder 10 Primary combustion cylinder 11 Secondary air flow path

Claims (3)

[Claims] A gas supply pipe (2) having a front end closed at an axis of a combustion air flow path (1) and a plurality of gas ejection holes (3) provided on a peripheral surface immediately before the end perpendicular to the axis. ), And a premixed gas burner provided with a flame holding plate (4) provided with the same number of combustion air injection ports as gas injection holes at a position before the tip end.
As a plurality of combustion air outlets of the flame holding plate (4), an air nozzle cylinder (5) protruding beyond the gas outlet (3) and a non-projecting outlet (4a) are alternately arranged in the circumferential direction. It is arranged so that a part of the gas flow from the gas discharge hole is blown out immediately before the gas outlet (4a) where the gas flow does not protrude, and a part of the gas flow collides with the protruding peripheral wall of the air nozzle cylinder (5). Characterized by a premixed gas burner. 2. A premixed gas burner according to claim 1, wherein the distance L between the peripheral wall of the protruding air nozzle cylinder (5) and the gas ejection hole (3) is in the range of 2 mm to 5 mm. 3. A primary combustion cylinder (10) is provided outside a combustion air flow path (1) with a secondary air flow path (11) outside to distribute combustion air to primary air and secondary air. 2. The premixed gas burner according to claim 1, wherein after partially burning the excess air ratio in the primary combustion in the range of 0.5 to 0.8, complete combustion is performed with the secondary air.