JPH08166111A - Burner device and hot air heating device using the same - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention aims to achieve low NOx in the entire combustion range. A plurality of main flame holes 2 provided on a surface facing the longitudinal direction of the burner 1 main body or on two surfaces continuous with the facing surface, and a primary combustion chamber wall surrounding the burner 1 main body or the main flame hole 2 3, a primary flame hole 4 formed in the primary combustion chamber, a plurality of auxiliary air ports 5 provided in the primary combustion chamber wall 3, a secondary combustion chamber wall 6 surrounding the primary combustion chamber, and A secondary flame hole 7 formed in the secondary combustion chamber wall 6 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner device for reducing NOx.

[0002]

2. Description of the Related Art Conventionally, a burner device of this type is, for example,
There is one disclosed in Japanese Examined Patent Publication No. 62-39329.
As shown in FIG. 4, the structure is such that the main flame holes 12
The burner 11 having the above structure was covered with the primary combustion chamber wall 13 having the primary flame holes 14. With this configuration, the primary flame 15 is formed on the main flame hole 12 and the secondary flame 16 is formed on the primary flame hole 14, so that the flame temperature is lowered and low NOx combustion is realized.

[0003]

However, in the above conventional structure, when the oxygen concentration in the atmosphere decreases, the primary flame 1
5 easily lifts from the main flame hole 12. When the primary flame 15 lifts, the primary flame is formed inside the secondary flame 16,
Since the two-stage combustion is not formed, there is a problem that it becomes difficult to maintain the low NOx combustion. However, simply suppressing the lift of the primary flame 15 can be solved by providing the auxiliary air port 17 in the primary combustion chamber wall 13.
However, the air flowing into the primary combustion chamber 13 from the auxiliary air port 17 raises the temperature of the primary flame 15 and further raises the temperature of the secondary flame 16. As a result, the lift phenomenon can be suppressed,
It becomes impossible to maintain low NOx combustion. In any case, the conventional two-stage combustion technique has a problem in that low NOx combustion cannot be maintained when the oxygen concentration in the atmosphere decreases.
Further, since the load of the primary flame hole 14 is usually designed according to the maximum combustion, the secondary flame 16 on the primary flame hole 14 returns to the main flame hole 12 and the two-stage combustion is formed when the combustion amount decreases. It will not be done. Therefore, there is also a problem that the NOx concentration increases when the combustion amount decreases.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a burner device which realizes low NOx combustion in the entire combustion region and maintains low NOx combustion even when the atmospheric oxygen concentration is reduced. It is a thing.

[0005]

In order to achieve the above object, the present invention has a plurality of main flame holes on a surface facing the longitudinal direction of the burner body or on two surfaces continuous with the facing surface, and the burner body. Alternatively, a primary combustion chamber wall surrounding the main flame hole, a primary flame hole formed in the primary combustion chamber, a plurality of auxiliary air ports provided in the primary combustion chamber wall, and surrounding the primary combustion chamber. This is a configuration including a secondary combustion chamber wall and a secondary flame hole formed in the secondary combustion chamber wall.

Further, the difference in height in the vertical direction between the plurality of main flame holes and the plurality of auxiliary air ports on the two surfaces connected to the surface facing the longitudinal direction of the burner body is 10 times the hydraulic radius of the main flame holes. The gap between the main flame hole and the auxiliary air port in the horizontal direction is at least twice the hydraulic radius. The portion of the primary combustion chamber wall where the plurality of auxiliary air ports are provided is the bottom surface or the side surface. The primary flame and the load of the flame are reduced in the order of the main flame, the primary flame and the secondary flame, and the primary flame and the secondary flame are composed of a single hole. The plurality of main flame holes and auxiliary air ports have a slit shape,
It has a round hole shape, an elongated hole shape, or a combination thereof. The secondary flame holes are provided on the primary combustion chamber wall and the secondary combustion chamber wall, which face the main flame holes.

[0007]

According to the present invention, since the plurality of main flame holes are formed on the two surfaces which are continuous with the surfaces facing the longitudinal direction of the burner body, the flame hole load is lower than that of the conventional burner. Therefore, the jet speed of the air-fuel mixture becomes slow, and the primary flame spreads over the main flame hole. Therefore, even if the oxygen concentration in the atmosphere is reduced, the primary flame does not lift as in the conventional case, and stable two-stage combustion can be formed.

Further, a primary combustion chamber wall surrounding the burner body or the main flame hole, a primary flame hole formed in the primary combustion chamber, and a plurality of auxiliary air ports provided in the primary combustion chamber wall, A secondary combustion chamber wall surrounding the primary combustion chamber,
In a configuration including a secondary flame hole formed in the secondary combustion chamber wall, the load of the primary flame hole and the flame hole is reduced in the order of the main flame hole, the primary flame hole, and the secondary flame hole, The primary flame hole and the secondary flame hole consist of a single hole, and the secondary flame hole has two stages in the entire combustion region due to the structure provided on the primary combustion chamber wall and the secondary combustion chamber wall on the surface facing the main flame hole. It becomes possible to burn. For example, when the combustion amount is large, the primary flame is formed on the main flame hole and the secondary flame is formed on the secondary flame hole. When the amount of combustion decreases, the secondary flame is formed on the primary flame hole by the secondary air flowing into the secondary combustion chamber from the secondary flame hole. As a result, low NO in the entire combustion range
x conversion is realized. The secondary air flowing in from the auxiliary air port faces the unburned gas discharged from the main flame hole at the position where the secondary air blows out due to the above-described configuration. Therefore, the secondary air is not directly supplied to the primary flame, but the unburned gas is burned at the auxiliary air port. The flame on this supplemental air is lean in fuel, while the primary flame on the main pits is rich in fuel. That is, the two-stage combustion and the rich-lean combustion are performed at the same time, and more excellent reduction of NOx can be realized.

Therefore, by combining the area, shape, arrangement, and position of the main flame holes of the auxiliary air ports described in this configuration, the ratio of the two-stage combustion and the rich-lean combustion can be controlled. By increasing the ratio of dark and light combustion, it is possible to reduce NOx while reducing the yellow region and the soot generation region.

[0010]

Embodiments of the present invention will be described below with reference to FIGS. In FIG. 1, reference numeral 1 denotes a burner main body having a main flame hole 2, and a plurality of main flame holes 2 are provided at a surface facing the burner 1 main body and two surfaces continuous with the surface.
The main flame hole 2 may have a flame hole shape with a long slit as shown in FIG. 1, or the opposing surfaces may be slits and the two continuous surfaces may be round holes. 3 is the wall of the primary combustion chamber,
A primary flame hole 4 consisting of a single hole at a position facing the main flame hole 2
Have. A plurality of auxiliary air ports 5 provided in the primary combustion chamber wall 3
Is the vertical height difference of the hydraulic radius of the main flame hole 2 is 1
It is set to 0 times or less, and the gap between the main flame hole 2 and the auxiliary air port 5 in the horizontal direction is set to 2 times or more of the hydraulic radius. In FIG. 1, the portion of the primary combustion chamber wall 3 where the plurality of auxiliary air ports 5 are provided is the bottom surface, but FIG. 2 is an embodiment in which the auxiliary air ports 5 are provided on the side surface. Reference numeral 6 denotes a secondary combustion chamber wall, which is a single hole at a position facing the main flame hole 2 and has a secondary flame hole 7. The flame hole load is smaller in the order of the main flame hole 2, the primary flame hole 4, and the secondary flame hole 7.
Reference numeral 8 denotes a combustion detection sensor, which faces the primary combustion chamber and is located directly above the main flame hole 2 and the auxiliary air port 5, and the vertical height is 5 times or more the hydraulic radius from the surface of the main flame hole 2 to 50 times or less. did.

In the above structure, since the plurality of main flame holes 2 are formed on the two surfaces which are continuous with the surface facing the longitudinal direction of the burner 1, the flame hole load becomes lower than that of the conventional burner. For this reason, the speed at which the air-fuel mixture is ejected from the main flame hole 2 becomes slow, and the primary flame 9 spreads and is formed on the main flame hole 2. Therefore, even if the oxygen concentration in the atmosphere decreases, the primary flame 9 does not lift as in the conventional case, and stable two-stage combustion can be formed.

Further, the burner 1 main body or the main flame hole 2
A primary combustion chamber wall 3, a primary flame hole 4 formed in the primary combustion chamber, a plurality of auxiliary air ports 5 provided in the primary combustion chamber 3 wall, and a secondary combustion chamber surrounding the primary combustion chamber. With the configuration including the secondary combustion chamber wall 6 and the secondary flame hole 7 formed in the secondary combustion chamber wall 6, the load of the flame holes is the main flame hole 2, the primary flame hole 4, and the secondary flame hole 7. The primary flame hole 4 and the secondary flame hole 7 are composed of a single hole, and the secondary flame hole 7 has the primary combustion chamber wall 3 and the secondary combustion chamber wall 6 facing the main flame hole 2. Since the primary flame 9 is installed in the main flame hole 2 when the combustion amount is large,
On top, the secondary flame 10 is formed on the secondary flame hole 7. When the combustion amount decreases, the secondary flame 10 is formed on the primary flame hole 4 by the secondary air that has flowed into the secondary combustion chamber from the secondary flame hole 7. As a result, low NOx is realized in the entire combustion range. With the above-described configuration, the secondary air flowing in from the auxiliary air port 5 faces the unburned gas discharged from the main flame hole 2 at the blowing position. For this reason, the secondary air is
The unburned gas is burned at the auxiliary air port 5 without being directly supplied to. The flame on the auxiliary air port 5 is lean in fuel, while the primary flame 9 on the main flame hole 2 is rich in fuel. That is, the two-stage combustion and the rich-lean combustion are performed at the same time, and more excellent reduction of NOx can be realized.

Therefore, by combining the area, the shape, the arrangement, and the position of the main flame hole of the auxiliary air port 5 described in this configuration, the ratio of the two-stage combustion and the rich-lean combustion can be controlled. By increasing the ratio of dark and light combustion, it is possible to reduce NOx while reducing the yellow region and the soot generation region.

FIG. 3 shows an embodiment in which a burner is incorporated in a warm air heater according to the present invention. A burner composed of a plurality of main flame holes 2 provided on a surface facing the longitudinal direction of the burner 1 main body or on two surfaces continuous with the facing surface, and a primary combustion surrounding the burner 1 main body and the main flame hole 2 A chamber wall 3, a primary flame hole 4 formed in the primary combustion chamber, a plurality of auxiliary air ports 5 provided in the primary combustion chamber wall 3, and a secondary combustion chamber wall 6 surrounding the primary combustion chamber. And a secondary flame hole 7 formed in the secondary combustion chamber wall 6. Further, the combustion detection sensor 8 provided directly above the main flame hole 2 and the auxiliary air port 5 in the primary combustion chamber, the combustion cylinder 11 surrounding the secondary combustion chamber wall 6 and having the upper and lower surfaces opened, and the hot air blowout A blower 13 is provided for sending air to the louver 12 and for inducing air in the combustion cylinder by the air blowing pressure.

When the combustion amount is large, the primary flame 9 is rich in fuel.
Is formed on the main flame hole 2, and the secondary flame 10 is formed on the secondary flame hole 7. On the auxiliary air port 5, by the secondary air induced by the blower 13 and the high temperature unburned gas generated from the main flame hole 2,
A flame with lean fuel is created. As a result, the two-stage combustion and the rich / lean combustion are simultaneously performed, and the NOx reduction can be realized.

[0016]

As described above, the burner device of the present invention has the following effects. Even if the atmospheric oxygen concentration decreases, the primary flame does not lift as in the conventional case, and stable two-stage combustion can be formed. When the amount of combustion is large, the primary flame is formed on the main flame hole and the secondary flame is formed on the secondary flame hole. When the amount of combustion decreases, the secondary flame is formed on the primary flame hole by the secondary air flowing into the secondary combustion chamber from the secondary flame hole. As a result, low NOx can be realized in the entire combustion range. The flame on the auxiliary air port is lean in fuel, and the primary flame on the main flame hole is rich in fuel. That is, the two-stage combustion and the rich-lean combustion are performed at the same time, and it is possible to further reduce NOx. In addition, by combining the area, shape, arrangement, and position of the main flame holes of the auxiliary air ports, the ratio of two-stage combustion and rich-lean combustion can be controlled. By increasing the ratio of dark and light combustion, it is possible to reduce NOx while reducing the yellow region and the soot generation region.

[Brief description of drawings]

FIG. 1 is a sectional view of a burner device using a slit in a main flame hole according to an embodiment of the present invention.

FIG. 2 is a sectional view of a burner device in which an auxiliary air port of another embodiment of the present invention is provided on a side surface of a wall of a primary combustion chamber.

FIG. 3 is a sectional view of the burner device of the present invention incorporated in a warm air heater.

FIG. 4 is a sectional view of a conventional burner device.

[Explanation of symbols]

 1 Burner 2 Main Flame Hole 3 Primary Combustion Chamber Wall 4 Primary Flame Hole 5 Auxiliary Flame Hole 6 Secondary Combustion Chamber Wall 7 Secondary Flame Hole 8 Combustion Detection Sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoichi Hara 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (9)

[Claims] 1. A plurality of main flame holes provided on a surface facing the longitudinal direction of the burner body or on two surfaces continuous with the facing surface, and a primary combustion chamber wall surrounding the burner body or the main flame hole. A primary flame hole formed in the primary combustion chamber, a plurality of auxiliary air ports provided in the primary combustion chamber wall, a secondary combustion chamber wall surrounding the primary combustion chamber and the secondary combustion chamber wall Burner device with secondary flame holes. 2. A difference in vertical height between a plurality of main flame holes and a plurality of auxiliary air ports on two surfaces that are continuous with a surface facing the longitudinal direction of the burner body is 10 hydraulic pressure radius of the main flame hole. 2. The burner apparatus according to claim 1, wherein the burner device is not more than double, and the horizontal gap between the main flame hole and the auxiliary air port is not less than twice the hydraulic radius. 3. The burner device according to claim 1, wherein the horizontal and vertical positions of the plurality of auxiliary air ports provided in the wall of the primary combustion chamber are the bottom surface or the side surface. 4. The burner device according to claim 1, wherein the primary flame holes and the secondary flame holes are provided on the primary combustion chamber wall and the secondary combustion chamber wall on the surface facing the main flame holes. 5. The burner according to claim 1, wherein the load of the flame holes is made smaller in the order of the main flame hole, the primary flame hole and the secondary flame hole, and the primary flame hole and the secondary flame hole consist of a single hole. apparatus. 6. The burner device according to claim 1, wherein the plurality of auxiliary air ports have a slit shape, a round hole shape, an elongated hole shape, or a combination thereof. 7. The burner device according to claim 1, wherein the main flame hole has a slit shape, a round hole shape, an elongated hole shape, or a combination thereof. 8. A combustion detecting element is provided directly above the main flame hole and the auxiliary air port, facing the primary combustion chamber, and the vertical height of the combustion detecting element is at least 5 times the hydraulic radius from the main flame surface. The burner device according to claim 1, wherein the burner device is set to 50 times or less. 9. A plurality of main flame holes provided on a surface facing the longitudinal direction of the primary air suction section, the mixing tube section, the burner body, or two surfaces continuous with the facing surface, the burner body and the main flame. A primary combustion chamber wall surrounding the hole, a primary flame hole formed in the primary combustion chamber, a plurality of auxiliary air ports provided in the primary combustion chamber wall, and a secondary combustion chamber surrounding the primary combustion chamber. A burner device comprising a wall and a secondary flame hole formed in the wall of the secondary combustion chamber, a combustion detection element provided directly above the main flame hole and the auxiliary air port in the primary combustion chamber, and the secondary combustion A warm air heating device comprising: a combustion cylinder which surrounds a chamber wall and whose upper and lower surfaces are open;