JPS63187014A - Burner - Google Patents

Abstract

PURPOSE:To reduce the exhaust quantity of NOx, widen the variable range of the combustion with no back fire, and further improve the durability and reliability of a burner by reducing flame temp. due to the division of flame hole plates. CONSTITUTION:The title device is composed of combustion plates 15 holding a plurality of flame hole plates 14 composed of wire gauzes in zigzag arrangement and outer walls 17 partially composed of heat-resisting glass 16. The pletes 14 on both plates 15 are facing each other in one-to-one. On the other hand, the plates 15 form a combustion chamber 20 with side plates 10 and a bottom plate 19 and they surround a plurality of flames stabilized on the plates 14. By this constitution, heat from the flames formed on the flame hole plates at the central part of the combustion plates is radiated satisfactorily to reduce flame temp. As a result, the generated amount of NOx can be reduced and simultaneously back fire does not occur to widen the variable range of the combustion amount. Further, the amount of rediation heat from the flame hole plates is increased to reduce temp. Because of the division with the combustion plates, the thermally deformed amount of the device is made small to increase the strength of the device and the durability of the device is improved accordingly.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a low NOx burner for an indoor open combustor.

BACKGROUND OF THE INVENTION Conventionally, a burner using complete premix combustion has been used as such a burner. For example, as shown in FIG. An outer premixture passage 3 was formed between the outer burner outlet plate 2 and the outer wall 1, and an inner premixture passage 5 was formed within the inner burner outlet plate 4.

Problem to be Solved by the Invention However, in such a burner, the amount of heat dissipated from the central part of each burner plate is extremely small compared to the peripheral part adjacent to the outer wall, so that the flame in the central part is Since the amount of heat dissipated via the plate is reduced, the temperature rise is large, and therefore the total amount of No work generated is increased. At the same time, the temperature rise in the center of the burner plate accelerated flashback, making the combustion rate variable range extremely small.

Furthermore, since the burner port plate generally reaches the highest temperature among the burner components, it is subject to deformation and deterioration due to ignition and extinguishment, as well as increases and decreases in the amount of combustion. Therefore, the burner port plate, which was held only at the periphery of the outer wall, was severely deteriorated, especially in the center, which limited its durability as a burner.

The present invention provides a burner with a simple structure, low NOx emissions, wide variable range of combustion amount, and high durability.

Means to Solve the Problem Combustion plates holding a plurality of burner ports made of wire mesh are opposed to each other at a certain distance, and a premixture passage is formed between the combustion plates and the outer wall, so that the combustion The combustion chamber was composed of a plate, a bottom plate, and a side plate.

For production The effect of this technical means is as follows.

With the above configuration, heat can be effectively dissipated from the flame formed on the burner port plate in the center of the combustion plate, and the flame temperature can be lowered, reducing the amount of nozzle generation and at the same time preventing backfire. This increases the combustion amount variable range. Furthermore, the amount of heat dissipated from the burner port plate itself increases and the temperature decreases, and since the burner plate itself is divided and held, the amount of thermal deformation is small and the strength is high, so its durability is dramatically improved.

Embodiment FIG. 1 is a perspective view of a burner according to an embodiment of the present invention, partially showing the internal components in cross section. First, the premixture 11 passes through the premixture supply pipe 12 and passes through the premixture passage 1.
Flows into 3. The premixture passage 13 includes a combustion plate 15 that holds a plurality of burner ports 14 made of wire mesh in a staggered arrangement.
and an outer wall 17 partially made of heat-resistant glass 16. Here, each burner port plate 14 on both combustion plates faces the opposing burner port plate one-on-one.

On the other hand, the combustion plate 15 forms a combustion chamber 2o 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 premixture 11 is large, that is, when the amount of combustion is large, the combustion load within the combustion chamber 2o increases, and the temperature within the combustion chamber rapidly increases. The flame is transferred to the combustion plate 15 by heat transfer or radiation. Flare plate 14. Although heat is radiated to the side plates 18, further to the bottom plate 19, etc., the flame in the center of the combustion chamber 20 in particular depends only on the heat radiated to the adjacent combustion plates 15° and flame opening plate 16.

Therefore, when there is a single burner port plate as in the past, the heat conduction within the burner port plate is very small, so the flame temperature facing the central part of the burner plate is higher than the periphery of the burner plate, and therefore the thermal No
x The amount generated 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 this embodiment, the flame in the central portion of the combustion chamber 20 is able to radiate sufficient heat. Furthermore, since the flame port plate 16 is divided, the flame is actually divided, and the surface area is increased, so that the amount of radiant heat is also increased. Therefore, the flame temperature is the combustion chamber 20
The total amount of NOx generated is drastically reduced.

Further, since the flame outlet plate 14 itself in the center of the combustion plate 16 has a large amount of heat radiation and its temperature is lowered, it is possible to eliminate the backfire that occurs when the amount of combustion is large, which has been a problem in the past. In other words, the combustion amount variable range has been expanded.

Further, each of the burner ports 14 on both combustion plates faces the opposing burner port plate one-on-one.

Therefore, the flame formed on each flame port plate 14 is extremely strong against blow-off. In other words, the flame is stabilized at the stagnation point formed near the center plane between both combustion plates. Therefore, even with the same combustion amount, stable combustion can be achieved even with the premixture 11 having a higher air ratio, the flame temperature can be lowered, and therefore NOx can be reduced, and the range in which the actual combustion amount can be varied can be expanded. Further, when the amount of combustion is large and the air ratio is high, the flame rises to the surface, and the flame port plate 16 has a larger area, and stable combustion occurs even on the combustion plate 15. As a result, the amount of heat dissipated by the flame increases, the temperature decreases, and low No.

On the other hand, when the amount of combustion is small, the flame is generally divided to increase the amount of heat released, which causes the flame temperature to drop too much, causing incomplete combustion and making it easier to generate carbon monoxide, etc. . However, in this embodiment, the burner ports 14 face each other. In other words, since the flames interfere with each other in the wake, the relatively incomplete combustion composition can be treated without being discharged downstream. Furthermore, since the plurality of flame port plates 14 are arranged in a staggered manner, incompletely burned compositions that come out between the flames can be sufficiently reacted. Therefore, stable combustion can be achieved even with a very small amount of combustion, so the range of variable combustion amount is 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 port plate 14 and combustion plate 15 by conduction or radiation, but the heat is transferred to the outer wall 17. Heat is not only transferred to the side plates 18 and the bottom plate 19, but also radiated to the outside of the burner via the heat-resistant glass 16. Therefore, the flame temperature decreases uniformly,
NOx emissions will decrease.

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

Effects of the Invention The present invention reduces the flame temperature and reduces N by dividing the flame port plate.
At the same time, the oX emission range can be reduced, flashback can be eliminated, and the combustion amount variable range can be widened. Furthermore, by lowering the temperature of the burner port plate and holding it separately, the strength is improved, and the durability and reliability of the burner can be increased.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional perspective view of a burner according to an 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 outlet plate, 4...
...Inner flame outlet plate, 14... Flame outlet plate, 15...
... Combustion plate, 16 ... Heat-resistant glass, 20.
... Combustion chamber.

Claims (4)

[Claims] (1) Combustion plates holding a plurality of flame port plates made of wire mesh are opposed to each other at a constant distance, the combustion chamber is constituted by the combustion chamber, the bottom plate and the side plate, and the premixture passage is formed by the combustion plate and the outer wall. A burner characterized by forming. (2) The burner according to claim 1, wherein a part of the outer wall is made of a heat-transparent material such as heat-resistant glass. (3) The burner according to claim 1 or 2, wherein in the facing combustion plates, each burner port plate faces one-to-one. (4) The burner according to claim 1, 2, or 3, wherein at least some of the burner ports located on the outer periphery of the combustion plate are arranged in a staggered manner.