JP2956242B2 - Combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a household combustion apparatus for reducing NOx and noise of a burner.

[0002]

2. Description of the Related Art A conventional combustion apparatus will be described below. As shown in FIG. 3, a first air-fuel mixture chamber 3 provided in a burner main body 2 having a first flame hole 1 and a first air-fuel mixture chamber 3
A second air-fuel mixture chamber 6 having a second flame hole 5 constituted by a wall plate 4 on both sides of the first air-fuel mixture chamber, and a burner main body 2 communicating the first air-fuel mixture chamber 3 and the second air-fuel mixture chamber 6 Mixture passage 7 provided in
And a flame stabilizing plate 8 for stabilizing the flame base between the first flame hole 1 and the second flame hole 5, and a primary air ratio of the second mixture chamber 6 in the wall plate 4. An air intake 9 is provided.
A large number of the burner bodies 2 having such a configuration are housed inside the burner case 10 with the wall plate 4 in contact with each other.
Arrows indicate the direction in which the mixture flows.

In the combustion device configured as described above, a stable rich flame having a low oxygen concentration is formed on the first flame hole 1. Further, a large amount of air from the air inlet 9 and the air-fuel mixture supplied from the air-fuel mixture passage 7 become a lean air-fuel mixture outside the flammable limit inside the second air-fuel mixture chamber 6, and the second flame hole 5
It burned out under the influence of the rich flame and was thermally affected by the rich flame, forming a lean flame with a high oxygen concentration. The rich flame and the lean flame are stabilized at the flame base by the effect of the small vortex formed on the flame holding plate 8, and the lean flame having a low NOx concentration and unstable characteristics is stabilized by the rich flame. To reduce the generation of NOx.

[0004]

However, in the above-mentioned conventional structure, the effect of reducing NOx is satisfied, but as the amount of combustion is reduced, the first and second flame holes 1 and 2 are reduced. As a result, the air-fuel mixture inside the second air-fuel mixture chamber 6 enters the flammable range, and the lean flame is mixed through the second flame hole 5. There is a problem that a backfire occurs at the outlet of the air passage 7 and the burner main body 2 and the wall plate 4 are abnormally heated.

Further, since the upper end surfaces of the wall plates 4 which are in contact with each other are not fixed, they are easily deformed, and a gap is formed between the adjacent wall plates 4 so that the secondary air inside the second mixture chamber 6 is formed. There was a problem that the amount was reduced.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and achieves both low NOx and high load combustion at the same time, and a variable width (TD) of a combustion amount by preventing a lean flame from returning to the outlet of a mixture passage of a lean flame.
It is an object of the present invention to provide a combustion device capable of reducing noise by expanding R), preventing burner deformation, and stabilizing a flame.

[0007]

In order to achieve this object, a combustion apparatus according to the present invention comprises a plurality of burner bodies having a first flame hole and a first air-fuel mixture chamber, and a plurality of burner bodies disposed between the burner bodies. Arranged, and an injection plate having a second flame hole portion composed of a large number of injection ports provided on the inclined portion, and a second flame formed on both sides of the first flame hole portion with the injection plate and the burner body. A mixture chamber, a mixture passage communicating with the first mixture chamber and the second mixture chamber and provided in the burner body, a flame holding chamber formed by the burner body and the injection plate, and It has a configuration provided with a flame holding mixture passage provided in the burner body so as to communicate with the mixture chamber.

[0008]

With this configuration, a lean mixture out of the flammable range is ejected at an angle from the ejection port of the second flame hole to inject the thermal mixture of the rich flame formed on the first flame hole. It ignites by being affected and performs lean combustion with low NOx characteristics, and the lean flame still contains a large amount of oxygen after combustion,
By being forcibly supplied to the rich flame, the flame becomes small and high load combustion is performed. At the base of the rich flame formed in the first flame hole, an auxiliary flame is formed by the combustion of the air-fuel mixture having a low flow rate from the flame holding chamber.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 showing one embodiment of the present invention, the same parts as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIG. 1 and FIG.
A first flame hole 1 having a large number of slits is provided on an upper surface of a burner main body 2 containing a flame, and a flame holding mixture passage 11 is provided at an upper portion on both sides of the burner main body 2 and a mixing passage is provided at a central portion. The air passages 7 are provided at optimal intervals in the longitudinal direction. Supports 12 are attached to both side surfaces of the burner main body 2, and an end of the injection plate 13 is inserted into a groove formed by the support 12 and the burner main body 2 to connect the adjacent burner main bodies 2. It is integrated. The injection plate 13 is formed by bending a flat plate, and a flame holding chamber 16 is formed by the burner main body 2, the horizontal portion 14, and the vertical portion 15. The second flame hole 5 composed of a large number of ejection ports is formed. Between the burner body 2 and the injection plate 13
The space on the downstream side of the mixture passage 7 surrounded by is the second mixture chamber 6. A throat portion 19 is formed on the upstream side of the burner main body 2, and a plurality of such burner main bodies 2 are arranged to form a burner block and housed inside the burner case 10. A fuel tube 21 provided with a nozzle 20 for ejecting fuel opposite to each throat portion 19 and a fan 22 are provided in the burner case 10.

[0010] The operation of the combustion apparatus configured as described above will be described below. A part of the combustion air supplied from the fan 22 flows into the burner main body 2 from the throat portion 19, and most of the remaining air is supplied to the burner main body 2.
And supplied to the respective second mixture chambers 6. On the other hand, the fuel supplied from the fuel pipe 21
The gas is ejected from 0 toward each throat portion 19, flows into the burner main body 2, mixes, and is supplied to the first air-fuel mixture chamber 3. The mixture in the first mixture chamber 3 has a primary air ratio of 30% to 60%. A part of this air-fuel mixture blows out from the first flame hole 1 and the flame-holding air-fuel mixture passage 11 to form a rich flame, and most of the remaining air-fuel mixture flows into the air-fuel mixture passage 7.
It is further guided into the second mixture chamber 6 and mixed with a large amount of air entering from between the burner bodies 2. At this time, the primary air ratio of the air-fuel mixture is about 170% to 250%, and after becoming a lean air-fuel mixture outside the flammable range and being homogenized,
The gas is jetted obliquely with respect to the jet direction of the first flame hole 1 from the jet port provided in the inclined portion 18 which is the second flame hole 5. The lean mixture is ignited by the thermal influence of the rich flame formed on the first flame hole 1 and burns lean. The lean flame still contains a large amount of oxygen even after the combustion, and by forcibly injecting and supplying the rich flame, the combustion reaction is promoted, and the flame is reduced to perform high load combustion.

Since the amount of generated NOx decreases as the temperature of the combustion reaction zone decreases, the leaner mixture containing a larger amount of air increases the heat capacity, lowers the flame temperature, and lowers the NOx. It is discharged from the flame holding chamber outlet 17 via the flame holding chamber 16. By setting the area of the flame holding mixture passage 11 to which the air / fuel mixture is supplied to be smaller than the area of the flame holding chamber outlet 17, the speed of the gas mixture ejected from the flame holding chamber outlet 17 becomes the first flame hole. The speed is lower than the speed of the air-fuel mixture ejected from 1 and a more stable flame is formed on the flame holding chamber outlet 17. The rich flame formed on the first flame hole 1 and the lean flame formed on the second flame hole 5 are stabilized by the thermal effect of the auxiliary flame and the difference in the flow rate of the jet air-fuel mixture. In addition, the combustion noise can be suppressed, and low NOx combustion can be realized as the entire burner block.

When the amount of combustion is small, the flow velocity of the mixture mixture in the first and second flame holes 1 and 5 becomes small, and the flame approaches the respective flame holes. .
Further, if the supply air amount fluctuates, the amount of combustion is small, so that the air-fuel mixture inside the second air-fuel mixture chamber 6 may enter the flammable range. At this time, the lean flame tends to advance into the second mixture chamber 6, but since the second flame hole 5 is set to a hole diameter smaller than the extinction diameter, the inside of the second mixture chamber 6 is reduced. The flame can be prevented from backfire. Therefore, even if the amount of combustion is reduced, there is no flashback, so that the burner body 2 is not abnormally heated.

Further, the injection plate 13 is formed by bending a plate material by integral molding, and a lower vertical wall 23 is inserted into a gap formed between the support 12 and the burner main body 2. Since the wall of the burner block 2 and the wall of the burner main body 2 are in close contact with each other, the rigidity of the burner block as a whole is increased, and thermal deformation is prevented. Therefore, the variation in the mixing ratio of the second mixture chamber 6 due to the generation of a gap that cannot be controlled in design can be reduced, and the combustion performance can be stabilized.

[0014]

As is apparent from the above description of the embodiment, the present invention provides a plurality of burner bodies having a first flame hole and a first mixing chamber, and is disposed between the burner bodies. And, an injection plate having a second flame hole portion composed of a large number of injection ports provided in the inclined portion, a second air-fuel mixture chamber formed by this injection plate and the burner main body, a first air-fuel mixture chamber, An air-fuel mixture passage provided in the burner main body by communicating the two air-fuel mixture chambers, and a flame holding chamber and a first air-fuel mixture chamber formed on both sides of the first flame hole portion by the burner main body and the injection plate. As described above, since the structure is provided with the flame holding mixture passage provided in the burner main body, low NOx and high load combustion can be achieved at the same time, and the variable width of the combustion amount can be reduced by preventing the backflow of the lean flame to the mixture passage outlet. It can realize an excellent combustion device that can reduce noise by expanding, preventing burner deformation, and stabilizing the flame. .

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a concept of a main part of a combustion apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the combustion apparatus according to the embodiment;

FIG. 3 is a schematic cross-sectional view showing a concept of a main part of a conventional combustion device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st flame hole part 2 Burner main body 3 1st air-fuel mixture chamber 5 2nd flame hole part 6 2nd air-fuel mixture chamber 7 Air-fuel mixture passage 11 Flame-storage air-fuel mixture passage 13 Injection plate 16 Flame-proof room

Continuation of the front page (51) Int.Cl. ⁶ identification code FI F23D 14/74 F23D 14/74 B (56) References JP-A-4-283307 (JP, A) JP-A-4-151411 (JP, A JP-A-4-273906 (JP, A) JP-A-4-28909 (JP, A) JP-A-4-158107 (JP, A) JP-A-2-21115 (JP, A) 115627 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F23D 14/02 F23D 14/08 F23C 11/00 329-330 F23D 14/62 F23D 14/74

Claims (1)

(57) [Claims] 1. A second burner body comprising a plurality of burner bodies having a first flame hole and a first air-fuel mixture chamber, and a plurality of ejection ports provided between the burner bodies and provided on an inclined portion. An injection plate having a flame hole, a second air-fuel mixture chamber formed on both sides of a first flame hole with the injection plate and the burner main body, the first air-fuel mixture chamber and the second mixture A gas mixture passage communicating with the air chamber and provided in the burner main body, and a burner main body provided so as to communicate the flame holding chamber formed by the burner main body and the injection plate with the first gas mixture chamber. A combustion device having a flame holding mixture passage.