JPH10141609A - Surface combustion burner to be provided with its combustion surface close to water cooling pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a burner plate from being overheated and hence prevent premixing gas from leaking from a distorted part of the burner plate due to heat by filling a heat insulation member between a burner plate fixing tool and a water cooling pipe disposed closest to the burner plate fixing tool. SOLUTION: A rectangular burner plate 1 being a mat formed with metal fibers for example is provided on a tip end surface of a mixer chamber 4, and a peripheral edge of line burner plate 1 is fixed to a burner plate fixing tool 5. On the side of a surface combustion burner where a flame is produced there are provided many water cooling pipes 6 and a water cooling pipe wall where the water cooling pipe 6 are connected through a fillet 9, and further a heat insulation member 7 is filled between the water cooling pipe 6 located in closest vicinity to the burner plate fixing tool 5 and the burner plate fixing tool 5. Hereby, reflected heat from the water cooling pipe 6 is shielded by the heat insulating member 7 to prevent the burner plate fixing tool 5 from being overheated so that distorsion of the burner plate fixing tool 5 due to heat is prevented from being produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface combustion burner provided with a combustion surface close to a water cooling pipe.

[0002]

2. Description of the Related Art It has been practiced to provide a combustion surface of a surface combustion burner close to a water cooling pipe to lower the flame temperature and reduce the amount of NOx generated during combustion. in this case,
The shorter the interval between the combustion surface and the water cooling tube, the shorter the time during which the flame temperature is high, and the amount of NOx generated can be reduced. Therefore, the distance between the combustion surface and the water cooling tube is reduced. However, when the gap between the combustion surface and the water cooling tube is small, the heat of the flame is reflected by the water cooling tube, and the burner plate fixture of the surface combustion burner is heated, causing distortion in the heated burner plate fixture. It was found that there was a risk that the premixed gas in the mixing chamber would leak.

[0003]

The problem to be solved by the present invention is that in a surface combustion burner provided with a water cooling tube in close proximity, the burner plate fixture is distorted by heat and premixed gas leaks from the distorted portion. It is to prevent that.

[0004]

Means for Solving the Problems Surface combustion in which a premixed gas obtained by mixing fuel gas and combustion air in a mixing chamber is injected from a burner plate provided downstream of the mixing chamber to generate a flame on the surface of the burner plate. A surface combustion burner in which a combustion surface of a burner is provided close to a side surface of a water cooling tube provided in a vertical direction, and a NOx generation amount is reduced by lowering a temperature of a flame by the water cooling tube. In the surface combustion burner, the periphery of which is fixed to the mixing chamber by the burner plate fixing device, a heat insulating material is filled between the burner plate fixing device and the water cooling pipe closest to the burner plate fixing device to thereby fix the burner plate fixing device. Prevent overheating.

In the surface combustion burner, the wall of the mixing chamber is divided into a tip side and a root side, and the wall on the tip side is a burner plate fixture, and the wall on the root side is a mixing chamber base side wall. The burner plate fixture is bent inward at the burner front end and bent outward at the base end, and the mixing chamber base side wall body is bent outward at the front end. The burner plate fixing device fixes the burner plate at the part bent inside the front end and overlaps the part bent outside the base end with the part bent outside the mixing chamber base side wall body front end. By adopting a configuration that fixes together, the burner plate fixture can be easily replaced, and if the strength of the burner plate fixture decreases,
Prevent distortion by replacing the burner plate fixture.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of an essential part when a surface combustion burner according to an embodiment of the present invention is provided in a multi-tube once-through boiler.
FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. In the surface combustion burner, a combustion air supply pipe 2 for supplying combustion air and a fuel gas supply pipe 3 for supplying fuel gas are connected to the root side, and the combustion air and fuel gas are sent into the mixing chamber 4. It is supposed to be. Mixing room 4
Is provided with a rectangular burner plate 1 which is a mat formed of, for example, metal fibers, and a peripheral edge of the burner plate 1 is fixed to a burner plate fixture 5. The wall of the mixing chamber 4 is formed of two parts, a root side and a tip side. The wall on the tip side corresponds to the burner plate fixture 5, and the root side corresponds to the mixing chamber root side wall 8. The side wall body has its front end bent outward. The burner plate fixture 5 bends the front end of the burner inward,
The burner plate 1 has a structure in which a base end is bent outward, and a portion bent inward of a front end covers the entire peripheral edge of the combustion side surface of the burner plate 1. The plate 1 is sandwiched, and the burner plate 1 is fixed to the burner plate fixture 5. Also,
The burner plate fixture 5 and the mixing chamber base side wall 8 are overlapped with the part bent outside the front end of the burner plate fixture 5 outside the front end of the mixing chamber base side wall 8. With bolts. On the flame generating side of the surface combustion burner, a number of water cooling pipes 6 (only some of which are shown) and water cooling pipe walls connecting the water cooling pipes 6 with fins 9 are provided on the flame generating side. The heat insulating material 7 is filled between the water cooling pipe 6 adjacent to the water cooling pipe 6, that is, the water cooling pipe 6 closest to the burner on the wall of the water cooling pipe, and the burner plate fixture 5.

In the combustion of the surface combustion burner, combustion air and fuel gas are supplied to a mixing chamber 4 through a combustion air supply pipe 2 and a fuel gas supply pipe 3 and mixed in the mixing chamber 4 to be burned as a premixed gas. The fuel is injected from the plate 1 to generate a flame 11 on the combustion surface side of the burner plate 1. Water is supplied to the inside of the water cooling pipe 6, and the flame 11 generated on the combustion surface side of the burner plate 1 is immediately deprived of heat by the water cooling pipe 6 and its temperature is lowered, so that the NOx generation amount is reduced. The water inside the water cooling tube 6 that has dropped and absorbed the heat is taken out as steam. At this time, the water cooling tube 6 has not only a function of absorbing heat but also a function of reflecting heat. By filling the heat insulating material 7 between the burner plate fixing device 5 and the water cooling tube 6 closest to the burner plate fixing device 5, the heat reflected from the water cooling tube 6 is blocked by the heat insulating material 7, and the burner plate Since the overheating of the fixture 5 can be prevented, it is possible to prevent the burner plate fixture 5 from being distorted by heat.

Further, since the burner plate fixture 5 is connected to and fixed to the mixing chamber base side wall body 8 outside the mixing chamber 4, the burner plate fixture 5 can be easily replaced. When the strength of the burner plate fixing device 5 is reduced, the occurrence of distortion is prevented by replacing the burner plate fixing device 5.

It is also conceivable to fill the space between the water cooling pipe 6 and the burner plate fixture 5 with a refractory material instead of the heat insulating material 7. However, in the case of the refractory material, the heat insulating effect is small,
It is not preferable because it may fall off.

[0010]

According to the present invention, the occurrence of distortion in the burner plate fixture can be prevented, and the leakage of the premixed gas from the mixing chamber can be completely prevented, thereby increasing the safety. .

[Brief description of the drawings]

FIG. 1 is a top sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Burner plate 2 Combustion air supply pipe 3 Fuel gas supply pipe 4 Mixing chamber 5 Burner plate fixing tool 6 Water cooling pipe 7 Insulation material 8 Mixing chamber root side wall body 9 Fin 10 Holding plate 11 Flame

Claims (2)

[Claims] 1. Combustion of a surface combustion burner in which a premixed gas obtained by mixing fuel gas and combustion air in a mixing chamber is injected from a burner plate provided downstream of the mixing chamber to generate a flame on the surface of the burner plate. A surface combustion burner provided with a surface close to the side surface of a vertically provided water cooling tube and reducing the amount of NOx by reducing the temperature of the flame with the water cooling tube. A surface combustion burner fixed to a mixing chamber by a burner plate fixture, wherein a heat insulating material is filled between the burner plate fixture and a water cooling pipe closest to the burner plate fixture. 2. The surface combustion burner according to claim 1, wherein the wall of the mixing chamber is divided into a tip side and a base side, and the tip side wall is mixed with a burner plate fixture and the base side wall is mixed. The burner plate fixture is formed by bending inward at the burner front end and bending outward at the base end.The mixing chamber base side wall is bent outward at the front end. The burner plate fixing device fixes the burner plate at the part bent inside the front end,
The burner plate fixture can be easily replaced by a configuration in which the part bent outside the base end and the part bent outside the base wall end of the mixing chamber are overlapped and fixed. Characterized by a surface burning burner.