JP3558461B2 - Combustion equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention suppresses the generation of excess fuel mixture (rich mixture) and the excess air mixture (pale mixture) and was allowed simultaneous burning of nitrogen oxides (NO _X), relates to a so-called thick and thin fuel combustion apparatus.
[0002]
[Prior art]
Conventionally, thick and thin fuel combustion apparatus is known as one of the combustion device to reduce the NO _X. This device simultaneously ejects a rich mixture with a low air ratio (the ratio of the actual air amount to the theoretical air amount) from some of the multiple outlets, and a lean mixture with a high air ratio from the other outlets. And burn it.
[0003]
For example, in Japanese Unexamined Patent Publication No. Hei 6-347003, as shown in FIG. 13, a dark side burner 60 is integrally formed on one side with a central partition plate 75 therebetween, and a light mixing unit 70 is integrally formed on the other side. An arrangement in which the burner units 80 are juxtaposed at intervals is disclosed. The rich-side burner 60 sucks and mixes the fuel gas and the combustion air to blow out a rich air-fuel mixture having a low air ratio from the deep-side flame outlet 63. A light air-fuel mixture having a higher air ratio than the rich air-fuel mixture is ejected from the light-side flame port 73 thus obtained. As a result, a rich air-fuel mixture is blown out from the deep-side burner port 63 of each deep-side burner 60, and at the same time, a light-fuel mixture is blown out from the light-side burner port 73 between the deep-side burners 60 to perform rich-light combustion. Then, it is lack of oxygen at the base of the flame from the dark side flame hole 63, upward becomes oxygen-deficient by the exhaust gas of the flame from the light side flame hole 73 is produced of the NO _X is suppressed. On the other hand, in the light flame 76 from the light side flame port 73, since the fuel gas is lean, the flame temperature is lowered and the generation of NO _X is suppressed, and the low NO _X as a whole is achieved by the synergistic effect of these.
In addition, since the light mixing unit 70 is formed integrally with the dark side burner 60, it is not necessary to individually arrange the light mixing units 70 between the dark side burners 60, and the arrangement interval of the dark side burners 60 is reduced. It was an excellent thing that could be narrowed.
Japanese Patent Laid-Open No. 7-42917 discloses a second burner 8 in which a first burner 6 is formed on both sides of a first burner 6 of a first burner 5 as shown in FIG. The second burner 7 is provided with a burner 7. The second burner 7 is independent of the first burner 5. The common burner 7 sucks the fuel gas and the primary air and supplies the fuel gas and the primary air to the second burners 8 provided on both sides of the first burner 6. Shown is a gas appliance burner 100 having a mouth 9 provided above the inlet 3 of the first burner. The gas appliance burner 100 jets a lean air-fuel mixture from the first flame port 6 and a rich air-fuel mixture from the second flame port 8, and is supplied with secondary air from around the second flame port 8 to perform lean-burn combustion. .
[0004]
[Problems to be solved by the invention]
However, it has been shown in Japanese Patent Laid-Open No. 6-347013, since a small contact each burner unit 80 and the secondary air, in particular primary air ratio of light mixing unit 70 (hereinafter expressed as lambda _L) The higher combustion range had to be set at a higher level, and the good combustion range for the fluctuation of the primary air ratio was narrow. For example, as shown in FIG. 11, when the change of CO / CO _{2 in} the flue gas with respect to the change of the primary air ratio of the lean mixture is tested and graphed, the good combustion region is λ _L = 1.2 to 2 2 (CO / CO ₂ <0.005). In consideration of NO _X , λ _L > 1.8 (NO _X <50 ppm). For these reasons, λ _L is set to 180% or more (1.8 <λ _L , λ _L = about 1.9). Therefore, λ _L is close to the combustion limit, and stable combustion cannot be ensured due to slight fluctuations in the fuel gas composition, fuel gas amount, or combustion air amount.
Further, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 7-42917, stable combustion is ensured by supplying secondary air to the second flame port 8, and it is easy to adjust the air-fuel ratio of each burner. Since two inlets are provided, and the fuel gas and the primary air for combustion are supplied from the two inlets while being mixed, the mixing distance for sufficiently mixing has always been long. Therefore, the overall size (particularly, the width L shown in FIG. 14) cannot be made compact.
An object of the present invention is to provide a compact combustion apparatus which solves the above-mentioned problems, expands a good combustion area by changing the setting of a primary air ratio, and improves a method of mixing fuel gas and air. I do.
[0005]
[Means for Solving the Problems]
The combustion apparatus according to claim 1 of the present invention that solves the above-mentioned problems,
A light-side burner that inhales and mixes the fuel gas and the primary air for combustion to eject a light-air mixture having a stoichiometric air ratio or higher from a light-side flame port;
On both sides, a rich burner that ejects a rich air-fuel mixture that is less than the stoichiometric air ratio from the rich burner is provided integrally, and while supplying secondary air for combustion from around the rich burner, In a combustion device that burns a burner and a rich burner simultaneously,
The light-side burner has a first suction port for sucking primary air for combustion and fuel gas, and a second suction port for sucking only fuel gas. The gas is sucked and mixed, and the air-fuel mixture is distributed and supplied to the light-side flame port and the rich-side flame port, and the fuel gas is sucked from the second intake port and supplied to the supply path to the rich-side flame port. The gist is to make it erupt.
[0006]
The combustion device according to claim 2 of the present invention is the combustion device according to claim 1,
The ratio of the fuel gas amount of the rich burner to the total fuel gas amount (the sum of the fuel gas amount of the rich burner and the fuel gas amount of the light burner) is set to 30 to 40%.
The ratio of the primary air amount of the rich burner to the theoretical air amount is 50 to 80%,
The gist is that the ratio of the primary air amount of the light side burner to the theoretical air amount is set to 140 to 170%, and the ratio of the total secondary air amount to the theoretical air amount is set to 30 to 50%.
[0007]
In the combustion apparatus according to the first aspect of the present invention having the above-described structure, rich burners are integrally formed on both sides of the light burners, and air-fuel mixtures having different air ratios are ejected from the burner ports of the burners. And burn at the same time. The light-side burner sucks and mixes the primary air for combustion and the fuel gas from the first suction port and distributes and supplies the air-fuel mixture to the light-side flame port and the rich-side flame port. The fuel gas is sucked from the mouth and jetted out to the supply path to the rich side flame outlet. The section from the second intake port to the supply path to the rich-side flame port only needs to pass the fuel gas, and does not need to be mixed with air or the like. That is, in the rich side burner, fuel for increasing the concentration from the second intake port of the light side burner is added to the air-fuel mixture mixed to some extent, so that the fuel passage section can be shortened as much as possible and the whole can be made compact. .
[0008]
In the combustion apparatus according to the second aspect of the present invention, the ratio of the fuel gas, the ratio of the primary air amount, and the ratio of the secondary air amount of the rich burner and the lean burner are set and adjusted in appropriate ranges. It is stable and generates little harmful substances in flue gas.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of the combustion apparatus of the present invention will be described below.
FIG. 1 shows a schematic configuration of a burner 1 using a combustion device as one embodiment. The burner 1 has a plurality of burner units 10 as combustion devices arranged in a line at predetermined intervals, and fuel gas is supplied from nozzles 11 and 12 provided behind the burner units 10 at the same time. The primary air is also sucked into the burner unit 10, and the air-fuel mixture blows out from the upper flame port to form a flame, and the flame is supplied with the secondary air rising between the burner units 10. ing. The nozzles 11 and the nozzles 12 are arranged in two rows at predetermined intervals corresponding to each burner unit 10.
[0010]
As shown in FIGS. 2 and 3, the burner unit 10 includes a light-side burner 20 formed by folding a single stainless steel plate having a symmetrical concave portion formed by a press at the center to form an overlapping room, It is composed of a dark side burner 30 in which a similar stainless steel plate is further laminated on both sides of the light side burner 20 to form a room, and a flame port plate 50 inserted into the flame port 25 of the light side burner 20. You.
The light-side burner 20 is formed by folding a right mixing plate 21R and a mixing plate left plate 21L as shown in FIG. 22, the throat portion 23, the mixing chamber 24, and the light flame port 25) are integrally formed. However, the right plate 21R of the light mixing unit will be described because it is symmetric. Further, for easy understanding, the superposed flat plate portions are indicated by hatching.
The light mixing unit right plate 21R forming the side surface of the light-side burner 20 is formed with a concave portion by pressing, leaving a flat plate portion right 29R, and is provided at a lower left portion when viewed from the side surface to suck fuel gas and primary air for combustion. A funnel-shaped intake right 22R, a throat right 23R narrowing the flow path downstream thereof, a L-shaped bent right intake chamber 24R for mixing fuel gas and combustion primary air from the intake; And a right flame opening 25R for opening the air-fuel mixture and ejecting the air-fuel mixture. In the vicinity of the downstream of the throat portion 23R, there are provided a plurality of air-fuel mixture injection holes 28R right of small holes that have penetrated therethrough. In addition, a fuel opening right 26R formed by a groove opened to the left end is provided above the intake right 22R, and several small gas ejection holes 27R pass through the side surface of the fuel opening right 26R. .
The left plate 21L of the light mixing unit leaves the flat plate portion 29L left, and these concave portions (the intake left 22L, the throat left 23L, the mixing chamber left 24L, the light flame opening left 25L, and the fuel left 26L) are mixed with the light mixing unit. It is formed in a symmetrical shape with the right plate 23R, and an air-fuel mixture ejection hole left 28L and a gas ejection hole left 27L are also provided.
As shown in FIG. 6, the flame port plate 50 has two plates having two ears 50b protruding left and right and three protrusions 50a formed at equal intervals therebetween, and a groove corresponding to the protrusion 50a. Two plates are formed by overlapping the protrusion 50a and its groove.
[0011]
The dark side burner 30 is formed by integrally connecting the right and left symmetric dark mixing unit right plate 31R and the left and right thick mixing unit left plate 31L with three connecting plates 32 at the center, as shown in FIG. After being bent in a U-shape, the chambers are superimposed on both side surfaces of the light-side burner 20 to form air-mixture channels. In order to make the explanation easy to understand, similarly to the explanation of the light-side burner 20, first, the shape of the rich mixing unit right plate 31R constituting the side surface shape of the room will be explained.
The right plate 31R of the rich mixing unit forms a concave portion leaving a flat plate portion 39R (shown by hatching in the figure), and the concave portion is a passage of the air-fuel mixture ejected from the air-mixture ejection hole right 28R of the light mixing unit right plate 21R. And a gas mixture chamber right 36R through which gas ejected from the gas ejection hole right 27R of the light mixing unit right plate 21R and gas mixture from below pass therethrough. It has a deep flame opening right 37R that opens to the upper part and blows out the mixture.
On the other hand, the rich mixing unit left plate 31L has a left-right symmetric shape with the rich mixing unit right plate 31R, and a recess is formed leaving a flat plate portion left 39L (indicated by hatching in the figure). 35L, a gas introduction chamber left 36L, and a rich flame outlet left 37L.
[0012]
The burner unit 10 (see FIG. 2, FIG. 3, and FIG. 4) first bends the light mixing unit right plate 21R and the light mixing unit left plate 21L at the center, and superimposes the flat plate portion right 29R and the flat plate left 29L to spot. The light-side burner 20 is formed by welding, and the flame port plate 50 is inserted into the flame port 25 through the upper opening. Further, the dark side burner 30 bent in a U-shape with the connecting plate 32 as a bottom is superposed from outside, and the flat plate portion 39R and the flat plate portion 39L are spot welded. In this way, the intake 22, the throat 23, the mixing chamber 24, the light flame port 25, and the fuel port 26 are formed in the light burner 20 while leaving the flat plate portion 29. A chamber right 35R, a mixture gas introduction chamber left 35L, a gas introduction chamber right 36R, a gas introduction chamber left 36L, a rich flame opening portion 37R, and a rich flame opening left 37L are formed.
In assembling the light-side burner 20 and the dark-side burner 30, one plate is bent from the center and then spot-welded, so that the right and left light mixing unit right plates 21R, the light mixing unit left plates 21L, and the dark mixing unit right The positioning of the plate 31R and the left plate 31L of the rich mixing unit is simple and easy to manufacture.
[0013]
The supply of the fuel gas and the combustion air to the burner unit 10 is performed as follows (see FIGS. 2, 3, and 4). First, in the light-side burner 20, fuel gas is jetted from the nozzle 11 toward the intake 22. The jetted fuel gas passes through the throat portion 23, which is narrowed on the way, and enters the mixing chamber 24. At this time, at the same time, the primary air for combustion is sucked from the gap between the nozzle 11 and the intake port 22 and enters the mixing chamber 24 through the throat section 23. An air-fuel mixture of fuel gas and primary air for combustion (hereinafter, referred to as a lean air-fuel mixture) is sufficiently mixed in the mixing chamber 24 and jets upward through the flame port plate 50 of the light flame port 25. Further, a part of the lean air-fuel mixture enters the air-fuel mixture outlet chamber right 35R and the air-fuel mixture inlet chamber left 35L of the burner 30 on the rich side from the air-fuel mixture outlet hole 28R and the air-fuel mixture outlet hole 28L on the way.
Fuel gas from the nozzle 10 is also supplied to the rich burner 30 (see also FIG. 5). First, fuel gas is ejected from the nozzle 10 to the fuel port 26 of the light-side burner 20, and passes through the gas ejection hole right 27R and the gas ejection hole left 27L to the gas introduction chamber right 36R and the gas introduction chamber left 36L of the dark side burner 30. enter. No gap is provided between the nozzle 10 and the fuel port 26, and no primary air is sucked.
In the rich burner 30, the air-fuel mixture from the light-side burner 20 enters the air-fuel mixture introduction chamber right 35R and the air-fuel mixture introduction chamber left 35L from the air-fuel mixture ejection hole right 28R and the air-fuel mixture ejection hole left 28L, and the gas introduction chamber right 36R. After passing through the gas introduction chamber left 36L, the gas is blown upward from the rich flame mouth right 37R and the rich flame mouth left 37L. At this time, the fuel gas from the nozzle 10 is additionally supplied to the right gas introduction chamber 36R and the left gas introduction chamber 36L. That is, the fuel gas is ejected from the nozzle 10 to the fuel port 26 of the light-side burner 20, and passes through the gas ejection hole right 27R and the gas ejection hole left 27L to the gas introduction chamber right 36R and the gas introduction chamber left 36L of the dark side burner 30. enter. Since the primary air is not sucked from the fuel port 26, the air-fuel mixture (hereinafter, referred to as a rich air-fuel mixture) ejected from the rich-air-portion right 37R and the rich-air-portion left 37L is converted into a lean air-fuel mixture by a fuel gas. The concentration of fuel gas is increased by the amount added. In addition, since the fuel gas only passes through between the fuel port 26 and the gas ejection hole right 27R and the gas ejection hole left 27L without mixing anything, the distance can be reduced as much as possible.
[0014]
Next, a description will be given of the relationship generation amount and the air ratio of nitrogen oxides when burned with the combustion device 1 (NO _X) and carbon monoxide (CO).
FIGS. 9 and 10 are graphs in which the horizontal axis represents the air ratio and the vertical axis represents NO _X and CO / CO _2, and the change in the amount of both generated with respect to the change in the air ratio. The air ratio of the rich mixture is set to 0.6, the burner gas amount of the rich side: the burner gas amount of the light side = 3: 7, the secondary air ratio is set to 0.45, and FIG. _L) only is varied, a graph obtained by changing only the overall air ratio (lambda _T) in FIG. 10.
When the air ratio λ _L of the lean air-fuel mixture is changed, as shown in FIG. 9, a section where λ _L is extremely small (λ _L = 0.7 or less) and a section where λ _L is extremely large (λ _L = 2. 2 or more), CO / CO ₂ increases (CO / CO ₂ = 0.005 or more), and CO / CO ₂ becomes minimum and stable around λ _L = 1.4. NO _X gradually increases when λ _L is decreased, and exceeds 50 ppm when λ _L = 1.4 or less.
When the overall air ratio λ _T is changed, as shown in FIG. 10, an interval where λ _T is extremely small (λ _T = 1.4 or less) and an interval where λ _T is extremely large (λ _T = 3.0 or more) )), CO / CO ₂ increases (CO / CO ₂ = 0.005 or more), and CO / CO ₂ stabilizes at a minimum (CO / CO ₂ = 0.001) around λ _T = 2.25. NO _X gradually increases when λ _T is decreased, and exceeds 50 ppm when λ _T = 1.8 or less.
By the way, when the same test is performed in a conventional combustion device (a combustion device having a configuration shown in FIG. 13 disclosed in Japanese Patent Application Laid-Open No. 6-347013), graphs as shown in FIGS. 11 and 12 are obtained.
When the air ratio λ _L of the lean mixture is changed, as shown in FIG. 11, in a section where λ _L is small (λ _L = 1.2 or less) and in a section where λ _L is large (λ _L = 2.2 or more). , CO / CO ₂ increases (CO / CO ₂ = 0.005 or more), and CO / CO ₂ becomes minimum around λ _L = 1.7. There is no stable section. NO _X gradually increases as λ _L decreases, and exceeds 50 ppm at λ _L = 1.8 or less.
When the overall air ratio λ _T is changed, as shown in FIG. 12, in the section where λ _T is small (λ _T = 1.4 or less) and the section where λ _T is large (λ _T = 2.2 or more), CO 2 is reduced. / CO ₂ increases (CO / CO ₂ = 0.005 or more), and the CO / CO ₂ becomes minimum (CO / CO ₂ = 0.002) near λ _T = 1.8. There is no stable section.
NO _X gradually increases when λ _T is decreased, and exceeds 50 ppm when λ _T = 1.8 or less.
[0015]
Comparing the burner 1 of the embodiment with the conventional example, the burner 1 is supplied with the secondary air from around the rich-side flame at the rich-side burner 30 and the light-side burner 20 and burns simultaneously. In the air-fuel mixture, it is not necessary to make the primary air ratio extremely high, and good combustion can be performed together with the secondary air. Therefore, especially in the light side burner 20, the range of the air ratio width in the good combustion area is expanded to the lower air ratio side as compared with the conventional case where the ratio of the primary air is extremely high, and the secondary air is also reduced. In addition to providing a margin for changing the mixing ratio of the entire air including the air, the good combustion range is expanded.
For example, the good combustion width Δλ _T in the change in the overall air ratio λ _T is as narrow as Δλ _T = 0.8 in the conventional example, while Δλ _T = 1.6 in the burner 1, and CO / CO ₂ is also used in the embodiment. Is minimum and CO / CO ₂ = 0.001, whereas the conventional example is minimum and CO / CO ₂ = 0.002. A similar difference exists for the air ratio λ _L of the lean mixture. Moreover, lambda in the _L configuration, and select a point NO _X and CO / CO ₂ is small, the conventional example in lambda _L = 1.9, sets the lambda _L = 1.4 in the burner 1. However, the setting of λ _L = 1.9 in the conventional example is close to the upper limit of the flammable air ratio λ _L = 2.2, so that the flame lifts up due to a slight change in the air ratio, or exceeds the combustion limit and CO / CO ₂ will increase rapidly. On the other hand, the setting of λ _L = 1.4 for the burner 1 is at the center of the change width of the flammable air ratio, and the lift is hard to lift even with the change of the air ratio, so that the combustion state does not deteriorate.
Further, since good combustion can be achieved even when the overall air ratio λ _T is increased, λ _T can be increased and the dew point can be increased particularly when the combustion is performed with a small amount of gas. Therefore, generation of drain adhering to the heat exchanger is reduced, and durability is improved.
[0016]
Also, when compared with the combustion device disclosed in Japanese Patent Application Laid-Open No. 7-42917, the combustion device has a longer distance from the fuel port to the flame port, whereas the burner 1 of the present embodiment has a richer flame port. The fuel-air mixture supplied from the light mixing unit 21 is further mixed with fuel gas from the fuel port 26 to increase the fuel gas concentration. The length of the fuel gas passage can be shortened, and the whole becomes compact. As a result, in particular, the entire width L shown in FIG. 1 can be reduced.
In comparison with the conventional example, in the embodiment, the air ratio of the rich mixture is set to 0.6, the burner gas amount of the rich side: the burner gas amount of the lean side = 3: 7, and the secondary air ratio is set to 0.45. Although the graph was described using only the air ratio (λ _L ) of the lean air-fuel mixture or the overall air ratio (λ _T ), various tests are performed without being limited thereto, and a favorable combustion range is determined. Was. that is,
Gas ratio I _{R of} rich burner (fuel gas amount of rich burner / total fuel gas amount) = 30 to 40%
Light-side burner gas amount ratio I _L (light-side burner fuel gas amount / total fuel gas amount) = 60 to 70%
Air ratio λ _{R of} rich burner (primary air ratio of rich burner / theoretical air amount) = 50-80%
Light side burner air ratio λ _L (primary air ratio of light side burner / theoretical air amount) = 140 to 170%
Secondary air ratio λ ₂ (total secondary air amount / theoretical air amount) = 30 to 50%
It is.
However the whole of the fuel gas amount = amount of fuel gas + amount of fuel gas pale side burner λ _{T =} λ _R × dark side burners _{I R + λ L × I L} + λ 2
In this range, a result of CO / CO ₂ ≦ 0.005 (a safety standard value in our company) was obtained.
Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments at all, and it goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention. For example, in the embodiment, in assembling the light-side burner 20 and the dark-side burner 30, one plate is bent from the center and then spot-welded. However, the right and left light mixing unit right plates 21R and the light mixing unit left plate 21L, the rich mixing unit right plate 31R, and the rich mixing unit left plate 31L may be formed separately, and spot welding may be performed while positioning. In this case, the press die is not large and the die cost is low.
The slit plate 50 has substantially the same shape as seen from the top, as shown in FIGS. 2 and 6, but has a small size as shown in FIG. 7 or FIG. A combination of different slits or a corrugated flame outlet may be formed.
[0017]
【The invention's effect】
As described in detail above, according to the combustion apparatus of the first aspect of the present invention, the rich burner is supplied with the air-fuel mixture mixed to some extent from the light burner, and the air-fuel mixture is supplied with the air-fuel mixture from the fuel port. Since the fuel to be added is further added and mixed, the distance of the fuel passage section in the light-side burner can be minimized. Therefore, the whole can be made compact.
[0018]
According to the combustion apparatus of the second aspect, since the combustion conditions are set and adjusted in an appropriate range, the combustion is stable, and the generation of harmful substances in the combustion exhaust gas is small.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a combustion device as one embodiment.
2 is a top view and a side view of the burner unit 10. FIG.
3 is a sectional view and a rear view of the burner unit 10. FIG.
FIG. 4 is a component diagram of the light-side burner 20.
FIG. 5 is a component diagram of the dark side burner 30.
FIG. 6 is a perspective view of a flame port plate 50;
FIG. 7 is a top view of the burner unit.
FIG. 8 is a top view of the burner unit.
FIG. 9 is a graph showing a change in the generation amount of NO _X and CO / CO ₂ with respect to a change in the air ratio in the example.
FIG. 10 is a graph showing a change in the generation amount of NO _X and CO / CO ₂ with respect to a change in the air ratio in the example.
FIG. 11 is a graph showing a change in the generation amount of NO _X and CO / CO ₂ with respect to a change in the air ratio in the conventional example.
FIG. 12 is a graph showing a change in the generation amount of NO _X and CO / CO ₂ with respect to a change in the air ratio in the conventional example.
FIG. 13 is a schematic configuration diagram of a combustion device as a conventional example.
FIG. 14 is a schematic configuration diagram of a combustion device as a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Burner 10 Burner unit 11, 12 Nozzle 20 Light side burner 21R Light mixing unit right plate 21L Light mixing unit left plate 22 Intake port 23 Throat section 24 Mixing chamber 25 Light flame port 26 Fuel port 29, 39 Flat plate section 30 Dark side Burner 31R Rich mixing unit right plate 31L Rich mixing unit left plate 32 Connecting plate 35 Mixture introduction chamber 36 Gas introduction chamber 37 Rich flame outlet

Claims (2)

A light-side burner that inhales and mixes the fuel gas and the primary air for combustion to eject a light-air mixture having a stoichiometric air ratio or more from a light-side flame port;
On both sides, a rich burner that ejects a rich air-fuel mixture that is less than the stoichiometric air ratio from the rich burner is provided integrally, and while supplying secondary air for combustion from around the rich burner, In a combustion device that burns a burner and a rich burner simultaneously,
The light-side burner has a first suction port for sucking primary air for combustion and fuel gas, and a second suction port for sucking only fuel gas. The gas is sucked and mixed, and the air-fuel mixture is distributed and supplied to the light-side flame port and the rich-side flame port, and the fuel gas is sucked from the second intake port and supplied to the supply path to the rich-side flame port. A combustion device characterized by being ejected. The ratio of the fuel gas amount of the rich burner to the total fuel gas amount (the sum of the fuel gas amount of the rich burner and the fuel gas amount of the light burner) is set to 30 to 40%.
The ratio of the primary air amount of the rich burner to the theoretical air amount is 50 to 80%,
The ratio of the primary air amount of the light-side burner to the theoretical air amount is 140 to 170%,
2. The combustion apparatus according to claim 1, wherein the ratio of the total amount of secondary air to the theoretical amount of air is set to 30 to 50%.

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