JP2568534B2 - Burner - Google Patents

Description

FIELD OF THE DETAILED DESCRIPTION OF THE INVENTION Industry The present invention relates to low NO _x burner chamber open combustor.

2. Description of the Related Art Conventionally, a burner utilizing completely premixed combustion has been used as such a burner. For example, as shown in FIG. 2, a double cylindrical wire mesh is formed in an outer wall 1 made of heat-resistant glass. The outer premixed gas passage 3 is formed by the outer flame port plate 2 and the outer wall 1, and the inner premixed gas passage 5 is formed in the inner flame port plate 4.

Problems to be Solved by the Invention However, in such a burner, the central part of each flame port plate has an extremely small amount of heat radiation as compared with the peripheral part adjacent to the outer wall, so that the flame at the central part is the flame port. temperature rise because the heat dissipation is reduced over the plate is large, thus had become much NO _x emissions. At the same time, the rise in temperature at the center of the flame plate accelerated the flashback and made the combustion amount variable range very small.

Further, since the flame plate generally has the highest temperature among the burner components, it is considerably deformed and deteriorated due to ignition, fire extinguishing, and an increase or decrease in the amount of combustion. Therefore, the flaring plate held only by the peripheral portion by the outer wall has a remarkable deterioration particularly in the central portion, and is the main cause of limiting the durability as a burner.

The present invention has less NO _x emissions with a simple structure, wide combustion amount variable range, moreover there is provided a durable burner.

Means for solving the problem A combustion plate holding a plurality of flame opening plates formed of a wire mesh is opposed to each other at a fixed distance, and a premixed air passage is formed by the combustion plate and the outer wall, and the combustion plate and The combustion chamber was constituted by the bottom plate and the side plates.

Operation The operation of this technical means is as follows. With the above structure, heat radiation from the flame formed in the combustion plate central portion of the burner port board can be reduced satisfactorily conducted flame temperature, at the same time can reduce the NO _x generation amount, occur backfire And the variable combustion amount range is widened. Furthermore, the amount of heat radiation of the flame plate itself increases to lower the temperature, and since it is divided and held by the combustion plate, the amount of thermal deformation is small and the strength is high, so that its durability is dramatically improved.

FIG. 1 is a perspective view of a burner according to an embodiment of the present invention.
The internal configuration is shown by a partial cross section. First, the premixed gas 11 flows into the premixed gas passage 13 via the premixed gas supply pipe 12. The premixed gas passage 13 is composed of a combustion plate 15 holding a plurality of flame opening plates 14 formed of a wire mesh in a staggered arrangement, and an outer wall 17 partially formed of heat-resistant glass 16. Here, the flame plate 14 on each of the combustion plates is opposed to the facing flame plate in a one-to-one manner. On the other hand, the combustion plate 15 forms a combustion chamber 20 from the side plate 18 and the bottom plate 19, and surrounds a plurality of flames stabilized on the flame port plate 14.

The specific operation of this embodiment having such a configuration will be described below.

When the flow rate of the premixed gas 11 is large, that is, when the amount of combustion is large, the combustion load in the combustion chamber 20 increases, and the temperature of the combustion chamber rapidly increases. Flames are burned by heat transfer or radiation
The heat is radiated to the flame plate 14, the side plate 18, the bottom plate 19 and the like.
It depends only on heat radiation to the flame plate 16. Therefore, when a single flame plate is used as in the prior art, since the heat conduction in the flame plate is very small, the flame temperature facing the central portion is higher than the peripheral portion of the combustion plate. NO _x generation was increasing. However, due to the presence of the highly thermally conductive combustion plate 15 in addition to the flame port plate 16 as in the present embodiment, the flame in the center of the combustion chamber 20 can sufficiently radiate heat. Further, since the flame opening plate 16 is divided, the flame is actually divided, and the amount of radiated heat is increased because the surface area is increased. Therefore, the flame temperature is lowered and made uniform in the combustion chamber 20, and the total NO
_x Production is drastically reduced.

In addition, since the flame plate 14 itself at the center of the combustion plate 15 also has a large amount of heat radiation and a reduced temperature, it is possible to eliminate the conventional problem of flashback when the amount of heat radiation is large. That is, the combustion amount variable range can be expanded.

Further, the flame plate 14 on each of the combustion plates is opposed to the opposed flame plate in a one-to-one manner. For this reason, the flame formed on each flame opening plate 14 is very strong against blow-off. That is, the flame is stabilized at the stagnation point formed near the center plane between the two combustion plates. Therefore, even with the same combustion amount, the premixed gas 11 having a higher air ratio
But because the stable combustion can be realized, reduction in the flame temperature, thus it is possible to perform the low NO _x reduction, it is possible to widen the substantial combustion amount variable range. Further, when the amount of combustion is large and the air ratio is high, the flame rises, has a larger area than the flame port plate 16, and stably burns on the combustion plate 15. As a result, increases the heat dissipation of the flame, the temperature can be achieved is a low NO _x reduction decreases.

Conversely, when the combustion amount is small, generally the flame temperature is too low because the flame is divided and the heat release amount is increased, so that incomplete combustion is likely to generate carbon monoxide and the like. . However, in the present embodiment, each flame plate 14 faces each other. In other words, the configuration is such that the incomplete combustion composition, which is relatively generated because the flames interfere with each other in the wake, can be processed without being discharged downstream. Further, since the plurality of flame opening plates 14 are staggered, the incomplete combustion composition that escapes from between the flames can be sufficiently reacted. Therefore, stable combustion can be realized even with a very small amount of combustion.
The combustion variable range has been considerably expanded.

On the other hand, the heat-resistant glass 16 provided on the outer wall 17 is effective in lowering the flame temperature. The flame radiates heat to the flame plate 14 and the combustion plate 15 by conduction or radiation.
The heat is not only transmitted to the side plate 18 and the bottom plate 19 but also radiated to the outside of the burner via the heat-resistant glass 16 by radiation. Thus flame temperature uniformly reduced, NO _x emissions are reduced.

As described above, the durability is improved by lowering the flame temperature and lowering the temperature of each flame port plate 14, and the holding of the flame port plate 14 by the combustion plate 15 increases the strength of the flame port plate 14. And thus the reliability of the burner as a whole is dramatically improved.

The present invention reduces the flame temperature by dividing the flame plate
At the same time reducing NO _x emissions amount it can be widely combustion amount variable range without backfire. Further, the strength is improved by lowering the temperature of the flame plate and maintaining the flame dividedly, so that the durability and reliability as a burner can be enhanced.

[Brief description of the drawings]

FIG. 1 is a partially sectional perspective view of a burner according to one embodiment of the present invention,
FIG. 2 is a sectional view of a main part of a conventional burner. 1 ... Outer wall, 2 ... Outer flame plate, 4 ... Inner flame plate, 14
…… flame plate, 15… combustion plate, 16… heat-resistant glass, 20 ……
Combustion chamber.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Tatsuo Fujita 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. No. (72) Inventor Kenkichi Hashido 1006 Kadoma, Kazuma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (56) References JP-A-49-133391 (JP, A) JP-A-62-186106 (JP, A) JP-A-63-14007 (JP, A)

Claims (3)

(57) [Claims] A combustion plate having a plurality of burner plates is opposed to each other at a fixed distance, each of the burners is opposed to one to one, a combustion chamber is constituted by a combustion plate, a bottom plate and a side plate, and a combustion plate and an outer wall are used. A burner for forming a premixing passage, wherein the flame plate is formed of a wire mesh. 2. The burner according to claim 1, wherein a part of the outer wall is made of a heat-permeable material such as heat-resistant glass. 3. The burner according to claim 1, wherein at least a part of the flame plate located on the outer peripheral portion of the combustion plate is arranged in a staggered manner.