JPH0712312A - Rich or lean combustion burner - Google Patents

Abstract

PURPOSE:To enable a pulsating combustion of rich flame at a rich r lean combustion burner to be eliminated and further enable an amount of generated NOx and a discharging amount of non-ignited gas to be sufficiently restricted. CONSTITUTION:In a rich or lean combustion burner having a rich combustion burner A and a lean mixed combustion burner B alternatively arranged therein, a rich flame (a) is ignited along flame holding plates 1 installed an upper part of one side of the rich burner A, thereby the rich flame (a) is stably ignited to eliminate any pulsating combustion, lean mixture gas is guided to the rich mixture side by guiding pieces 2 set at the tip of each of the flame holding plates 1, resulting in that contact and mixing of the lean mixture gas against the rich flame (a) is well adapted to decrease its combustion temperature, its combustion characteristic is also superior and a generating amount of NOx and discharging amount of non-ignited gas can be sufficiently restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rich / lean burner which suppresses the production of NOx (nitrogen oxide) by simultaneously burning a rich mixture of excess fuel and a lean mixture of excess air.

[0002]

2. Description of the Related Art A rich burner unit (hereinafter referred to simply as "rich burner") that burns a rich air-fuel mixture (a gas-rich air-fuel mixture) and a light side that discharges an air-rich light air-fuel mixture (air-rich air-fuel mixture) The rich-lean combustion burner in which the mixture units (hereinafter simply referred to as the light mixture) are installed alternately,
It is already known to be one of the combustion burners effective for low NOx combustion.

As a conventional technique of the rich / lean combustion burner, for example, as disclosed in Japanese Patent Application Laid-Open No. 3-263502, and as shown in FIG. (The reference numeral is according to FIG. 14), a plurality of first
The burner tube A'and the plurality of second burner tubes B'are alternately joined to each other to form the first burner port 4'of the first burner tube A '.
And the second flame port 6'of the second burner tube B'is arranged side by side on the same plane.

In the above-mentioned prior art concentrated burner burner, the first flame port 4'of the first burner tube A'and the second flame port 6'of the second burner tube B'are aligned on the same plane. A rich air-fuel mixture (generally, air ratio λ <1) is ejected from the first burner port 4'of the first burner tube A ', and the second burner tube 6'of the second burner tube B'adjacent thereto is ejected. When a light air-fuel mixture (generally, air ratio λ> 1) is jetted and simultaneously burned, the first burner tube 4 ′ of the first burner tube A ′ is discharged.
Since the rich flame a ′ from No. 2 is burned in the exhaust gas of the lean flame b ′ from the second flame port 6 ′ of the second burner tube B ′, oxygen becomes insufficient, the flame temperature is lowered, and NOx generation is suppressed. .

On the other hand, in the lean flame b'formed at the second flame port 6'of the second burner tube B ', since the fuel gas is lean, the flame temperature is lowered and the generation of NOx is suppressed. Low NOx as a whole is achieved by the synergistic effect,
Moreover, it is possible to greatly change the amount of combustion.

[0006]

However, in the prior art, since the light air-fuel mixture ejected from the second flame port 6'of the second burner tube B'flows straight upward, the first burner tube A ' The amount of CO produced cannot be sufficiently suppressed because the contact mixture of the light air-fuel mixture with the rich flame a'is not good enough, and since the rich-lean combustion is a kind of oxygen deficient combustion, the oscillatory combustion due to the turbulence of the flame There is a problem that it easily occurs and it is easy to discharge unburned gas.

In view of the above problems of the prior art, the present invention stably burns the flame to eliminate oscillating combustion, and improves the contact mixing of the light air-fuel mixture with the rich flame to improve the CO production amount and The purpose is to provide a rich / lean combustion burner capable of sufficiently suppressing the amount of unburned gas emitted.

[0008]

To achieve the above object, the rich-lean burner according to the present invention burns a rich fuel-rich mixture as shown in the drawings corresponding to the embodiments. In a rich-lean combustion burner in which a rich burner A and a lean mixture B for ejecting an excess air-fuel mixture are alternately installed, the rich burner 4 is provided on one side of the rich burner 4 of the rich burner A. The main feature is to provide the flame holding plate 1 along which the rich flame a from No. 1 is provided.

As a related invention of the specified invention, a flame holding plate 1
A guide piece 2 for guiding the light air-fuel mixture from the light air-fuel mixture B to the adjacent rich air-fuel mixture is provided at the tip of the, or a guide hole 3 for guiding a part of the light air-fuel mixture to its own rich air-fuel mixture It is characterized in that it is provided on the piece 2.

The rich burner A and the light mixture B are installed so as to be inclined, and the flame holding plate 1 provided in the rich burner A is used as the rich burner port 4 of the rich burner A or the rich burner port 4 of the rich burner A. The discharge port 6 of the light mixture B is covered, or the flame port forming surface 5 of the rich burner A,
Alternatively, it is characterized in that the flame port forming surface 5 of the rich burner A and the discharge port forming surface 7 of the light mixture B are provided obliquely.

The rich burner A is characterized in that the rich flame port 4 is provided so as to be biased toward the flame holding plate 1.

[0012]

Since the rich / lean burner of the present invention is constructed as described above, the rich flame a of the rich burner A burns along the flame holding plate 1 to rectify the rich air-fuel mixture to produce the rich flame a. Stable and no oscillatory combustion occurs.

Further, the tip guide plate 2 of the flame holding plate 1 guides the light air-fuel mixture to the adjacent rich air-fuel mixture, and the guide holes 3 and the like 3 of the guide plate 2 are introduced.
Then, by introducing a part of the light air-fuel mixture into the rich air-fuel mixture of its own, the light-air mixture comes into contact with the rich flame a better, and the light-air mixture comes into contact with the rich flame a from the base portion. The combustion temperature is reduced, the combustibility is improved, NOx production is sufficiently suppressed, and the emission of unburned gas is also suppressed.

Moreover, the rich air-fuel mixture from the rich-side flame port 4 is jetted directly above, and the lean air-fuel mixture from the light-side flame port 10 formed in the upper part of the light-mixture B flows out laterally, so that the rich air-fuel mixture is produced. Since the discharge directions of the air-fuel mixture and the light-air mixture are different from each other, feedback of the oscillating combustion is less likely to occur, and from this point also, the oscillating combustion is suppressed in combination with the good combustion.

Further, the dense burner A and the light mixture B are installed at an angle, and the flame holding plate 1 covers the thick flame port 4 or the dark flame port 4 and the discharge port 6 of the light mixture B. The clogging of the flame mouth or the clogging of the discharge mouth due to the scale (combustion oxide) or the like falling from the upper side of the heat collector or the like is prevented, and moreover, the rich flame a with respect to the flame stabilizing plate 1 is also improved. Further, the flame burner forming surface 5 of the rich burner A or the flame burner forming surface 5 of the rich burner A and the light mixture B
By providing the discharge port forming surface 7 in a slanted shape, in combination with the presence of the flame holding plate 1, the clogging of the flame port or the clogging of the discharge port due to the fall of the scale or the like is prevented.

Furthermore, by bringing the dense flame port 4 of the rich burner A closer to the flame holding plate 1 side, an upward rich flame a is formed along the flame holding plate 1 and its flame length becomes long and flame holding Do not heat plate 1 red.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the rich burn burner of the present invention will be described below with reference to the drawings.

In the drawing, A is a rich burner for burning a rich mixture of excess fuel, and a large number of slit-shaped rich side flame openings 4 are formed in parallel on a flame opening forming surface 5 at the top of the burner. ,
A rich mixture of the fuel gas and the combustion air mixed in the mixing chamber 8 (for example, an air ratio of 1.0 or less) is jetted upward from the rich side flame port 4 and burned to form a rich flame a. It is configured to do.

As in the embodiment shown in FIGS. 1 to 12, the thick flame opening 4 has a flame opening extending over substantially the entire width of the flame opening forming surface 5 at the top thereof, as shown in FIG. As in the embodiment, the flame opening extending over approximately half the width of the flame opening forming surface 5 at the top thereof may be formed so as to be biased toward the flame holding plate 1 side. The width of the flame mouth is not limited to a half width. In FIG. 13, 13 is a sleeve flame mouth.

Reference numeral B denotes a light mixture for discharging a light air-fuel mixture in excess of air, and a large number of slit-shaped discharge ports 6 are formed on the discharge port forming surface 7 at the top of the mixture at regular intervals in parallel. 6, a light air-fuel mixture of the fuel gas and the combustion air mixed in the mixing chamber 9 (for example, an air ratio of 1.0 or more) is discharged upward, and between the upper end side surfaces of the adjacent rich burners A, A. It is configured to flow out from the upper light side flame port 10 formed in 1 above and burn to form a light flame b.

The rich burner A and the light mixture B are alternately arranged with a constant gap e, and the light mixture B is positioned below the rich burner A and the dark side of the rich burner A is located. A step h is provided between the flame port 4 and the discharge port 6 of the light mixture B so that the light mixture hits the base of the rich flame a, and the oxygen concentration of the light mixture is sufficiently reduced, and the light is supplied from the gap e. The air for combustion c is supplied by an air fan (not shown) or the like.

Therefore, although the rich air-fuel mixture (for example, having an air ratio of about 0.5) mixed in the mixing chamber 5 is ejected from the rich-side flame port 4 of the rich burner A, the light mixture B is mixed. The combustion air c flowing in through the gap e is mixed in the upper space of the discharge port 6 with the light air-fuel mixture discharged from the discharge port 6 (for example, an air ratio similar to the rich air-fuel mixture having an air ratio of about 0.5). A light mixture d having an air ratio of 1.0 or more is produced and flows out from the light side flame port 10 above.

Reference numeral 1 is a flame holding plate for passing the rich flame a of the rich burner A, which is extended to the downstream side (upper side) of one side of the rich burner port 4 of the rich burner A, and is provided to the rich burner A. The rich flame a formed at the rich side flame port 4 burns along the flame holding plate 1, whereby the rich mixture is rectified and the rich flame a is stabilized.

As the flame holding plate 1, as in the embodiment shown in FIGS. 1 and 2, a vertically extending flame holding plate 1 is provided at one upper side (the upper right side in the figure) of the rich burner A. Besides,
As in the embodiment shown in FIGS. 3 and 4, an oblique flame holding plate 1 that extends obliquely outward and upward may be provided at one upper side (upper left side in the drawing) of the rich burner A.

Further, as in the embodiment shown in FIG. 9, an oblique flame holding plate 1 extending obliquely outwardly is provided at one upper side (the upper right side in the figure) of the rich burner A, and as shown in FIG. As in the embodiment described above, a vertical flame holding plate 1 that extends upward in a state of projecting outward at one upper side of the rich burner A (upper right side in the drawing).
May be provided.

Reference numeral 2 is a guide piece for guiding the light air-fuel mixture from the light air-fuel mixture B to the adjacent rich air-fuel mixture.
That is, the lean mixture that is formed integrally with the flame holding plate 1 by bending in the direction opposite to the rich flame port 4 of the rich burner A (right side in the drawing) and is discharged from the discharge port 6 of the light mixture B. After d flows out from the light side flame port 10, the direction of the adjacent rich mixture (right side in the figure)
This improves the contact mixing of the light air-fuel mixture with the rich flame a.

As the guide piece 2, as in the embodiment shown in FIGS. 1 and 2, the tip end portion of the vertical flame holding plate 1 is bent outward (rightward in the drawing) at a right angle to form a horizontal shape. In addition to providing the guide piece 2 of FIG. 8, as in the embodiment shown in FIG. 8, the tip end portion of the vertical flame holding plate 1 is bent outward obliquely upward to provide the oblique guide piece 2, or As in the embodiment shown in FIG. 9, the tip end portion of the outwardly inclined oblique flame holding plate 1 is bent outward (to the right in the drawing) to provide the horizontal guide piece 2, or further, as shown in FIG. As in the embodiment shown in Fig. 3, the tip of the vertical flame holding plate 1 that projects outward (to the right in the drawing) is bent at a right angle outward (to the right in the drawing) to form the horizontal guide piece 2. It may be provided.

Numeral 3 is a guide hole for guiding a part of the light air-fuel mixture from the light mixture B to the rich air-fuel mixture of itself (a thick burner provided with an induction piece). It is provided in the above section and guides a part of the light air-fuel mixture discharged from the discharge port 6 of the light-air mixture B to its own rich air-fuel mixture to further improve the contact and mixing of the light air-fuel mixture with the rich flame a.

As the guide holes 3 and the like, as in the embodiment shown in FIGS. 5 and 6, a large number of guide holes 3 such as round holes and square holes are formed in the guide piece 2 in parallel, and in FIG. As in the illustrated embodiment, the guide piece 2 may be formed in a concavo-convex shape and a large number of recesses 3 may be formed in parallel.

Next, the rich burner A and the light mixture B are installed so as to be inclined, and the flame holding plate 1 provided in the rich burner A is used to provide the rich burner port 4 of the rich burner A or the rich burner port of the rich burner A. 4 and the discharge port 6 of the light mixture B are covered (in the embodiment shown in FIG. 11, the flame holding plate 1 covers only the dark side flame port 4 of the rich burner A). Using the rich burner A itself provided on the upper side of one side as it is, clogging of the flame port or ejection port due to the scale f falling from the upper side is effective in combination with the inclination of the flame port forming surface 5 and the ejection port forming surface 7. Can be prevented.

Further, the flame port forming surface 5 of the rich burner A, or the flame port forming surface 5 of the rich burner A and the discharge port forming surface 7 of the light mixture B are formed.
If it is provided obliquely, the scale or the like f falling from above will fall down and the clogging of the flame mouth can be prevented. In this case, as in the embodiment shown in FIG. 12, when the flame port forming surface 5 of the rich burner A having the oblique flame holding plate 1 is formed as a slope continuous with the flame holding plate 1, the effect is remarkable. .

Incidentally, in FIGS. 3, 4 and 12, 1
Reference numeral 1 is a rectifying plate provided near the light side flame port 10, which not only rectifies the light air-fuel mixture but also serves to prevent flashback.

The rich / lean combustion burner of the present invention described above is used as a heating source of a water heater, for example, as shown in FIG.
As shown in FIG. 2, the heat collector (not shown) is installed in the lower portion of the combustion chamber 12 to heat the heat collector.

In the above-mentioned structure, the rich air-fuel mixture is ejected from the rich-side flame port 4 of the rich burner A for combustion, and is also ejected from the ejection port 6 of the light mixture B to be mixed with the combustion air in the upper space thereof. The lean air-fuel mixture flows out from the light side flame port 10 and burns at the same time to perform rich-lean combustion.

In this case, the rich flame a formed at the rich flame port 4 of the rich burner A burns along the flame holding plate 1 on the upper side of one side, so that the rich mixture is rectified and the rich flame a Is stable and no oscillatory combustion occurs.

As shown in the embodiment shown in FIG. 13, the thick burner A of the rich burner A is biased to the flame holding plate 1 side so that the flameless opening is not formed on the flame holding plate side. For example,
With a high load of about 20-40 kcal / Hmm ² ,
The rich flame a is formed in a flame along the flame holding plate 1 and the flame length becomes long, so that the flame holding plate 1 does not glow red. This is because the base portion of the rich flame a formed at the dense flame opening 4 is the outer end g of the rich flame opening 4.
This is because the bent corner portion i of the flame holding plate 1 is formed.

Further, the light mixture B is discharged from the discharge port 6,
The light air-fuel mixture d mixed with the combustion air in the upper space flows out of the light side flame port 10, and then, for example, in the embodiment shown in FIGS. The induction piece 2 provided at the position is guided to the rich mixture (rich flame a) of the adjacent rich burner A (on the right side in the drawing) to be mixed in by contact (see FIG. 1).

Further, for example, in the embodiment shown in FIGS. 5 and 6, most of the light air-fuel mixture is concentrated by the thick burner A adjacent (on the right side in the drawing) by the guide piece 2 provided at the tip of the flame holding plate 1. Although it is introduced into the air-fuel mixture (rich flame a) and comes into contact therewith, part of it is introduced into the rich air-fuel mixture (rich flame a) of its own burner A (on the left side in the drawing) through the guide hole 3 and comes into contact therewith. It is mixed (see FIG. 5).

Therefore, since the lean air-fuel mixture d contacts the base of the rich flame a to form the lean flame b, the contact and mixing of the lean air-fuel mixture (including the exhaust gas of the lean flame b) with the rich flame a is improved. Since the combustion temperature of the rich flame a is lowered and the good combustion range is widened, the production amount of NOx emitted from the rich flame a is very small and the emission amount of unburned gas is effectively suppressed. It

Moreover, since the rich air-fuel mixture and the light air-fuel mixture have different discharge directions, feedback of the oscillatory combustion is less likely to occur, and the oscillatory combustion is suppressed in combination with the good combustibility.

Further, as in the embodiment shown in FIG.
If the thick burner A and the light mixture B are installed diagonally as a whole by using the shape of the thick burner A provided with the flame holding plate 1 on the upper part of one side as a whole, a scale or the like f falling from the upper side of the heat collector or the like f Is blocked by the flame holding plate 1 and does not enter the dark side flame port 4 or the discharge port 6, and the flame port of the rich burner A and the discharge port of the light mixture B are formed on the flame port forming surface 5 and the discharge port. This is effectively prevented due to the fact that the surface 7 is inclined.

As in the embodiment shown in FIG. 12, when the flame port forming surface 5 of the rich burner A having the oblique flame holding plate 1 is formed on the slope continuous with the flame holding plate 1, the heat collector is collected. The scale or the like f falling from above does not fall down on the flame holding plate 1 and the flame mouth forming surface 5 to enter the rich flame mouth 4, so that the burner clogging of the rich burner A is effectively prevented.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it is needless to say that the present invention can be implemented in various modes without departing from the gist of the present invention. is there.

[0044]

According to the rich / lean combustion burner of the present invention, since the rich flame of the rich burner burns along the flame holding plate, the rich air-fuel mixture is rectified to stabilize the flame and prevent the oscillating combustion.

The above-mentioned thick flame port of the rich burner is biased toward the flame holding plate side, and the pressure is increased by increasing the flow velocity by reducing the opening area, so that a rich flame having a long flame length is formed.
Therefore, even if the flame becomes small with a small input, the flame retaining plate will not glow red.

Further, since the lean air-fuel mixture is guided to the adjacent rich air-fuel mixture or the adjacent rich air-fuel mixture and its own rich air-fuel mixture by the induction piece or the induction piece and the induction hole, contact mixture of the light air-fuel mixture with the rich flame occurs. Since the combustion temperature is improved, the combustion temperature is lowered, and the combustibility is improved, the generation of NOx due to the combustion of the rich burner is sufficiently suppressed, and the emission of unburned gas is also suppressed.

In addition, since the rich air-fuel mixture and the light air-fuel mixture have different discharge directions, feedback of oscillating combustion is less likely to occur, and oscillating combustion is suppressed in combination with good combustibility.

Furthermore, if the burner is installed entirely diagonally using the shape of the rich burner as it is, or if the flame port forming surface of the rich burner or the discharge port forming surface of the light mixture is formed diagonally, It is possible to prevent the clogging of the flame or the ejection due to the falling scale.

[Brief description of drawings]

FIG. 1 is an overall schematic configuration diagram showing an embodiment of a rich / lean combustion burner of the present invention.

FIG. 2 is a perspective view thereof.

FIG. 3 is an overall schematic configuration diagram of another embodiment of a flame holding plate.

FIG. 4 is a perspective view of a main part thereof.

FIG. 5 is an overall schematic configuration diagram of an embodiment in which a guide piece has a guide hole.

FIG. 6 is a perspective view thereof.

FIG. 7 is a perspective view of a thick burner of an embodiment in which a guide recess is formed in a guide piece.

FIG. 8 is a schematic configuration diagram of a light and shade burner of another embodiment of the guide piece.

FIG. 9 is a schematic configuration diagram of a light and shade burner of a different embodiment of the flame holding plate and the guide piece.

FIG. 10 is a schematic configuration diagram of a dark and light burner of an embodiment in which a flame holding plate and a guide piece are different.

FIG. 11 is a schematic configuration diagram of an embodiment in which a thick burner and a light burner are installed so as to be entirely inclined.

FIG. 12 is a schematic configuration diagram of an embodiment in which the flame surface is inclined.

FIG. 13 is a schematic configuration diagram of an embodiment in which the burner port of the rich burner is biased.

FIG. 14 is a schematic configuration diagram of a main part of a conventional rich-lean combustion burner.

[Explanation of symbols]

 A thick burner B light mixture a rich flame 1 flame holding plate 2 induction piece 3 induction hole, etc. 4 dark side burner of rich burner 5 flame burner surface of rich burner 6 discharge port of light mixture 7 discharge of light mixture Exit formation surface

Front Page Continuation (72) Inventor Kiyoshi Kawashima 6-23 Taoyuan-cho, Mizuho-ku, Nagoya-shi Paloma Engineering Co., Ltd. Company Technology Department

Claims (6)

[Claims] 1. A rich-lean combustion burner in which a rich-side burner unit that burns an excess fuel-rich mixture and a lean-side mixture unit that discharges an excess air-rich mixture are alternately installed. A rich / lean combustion burner characterized in that a flame holding plate is provided on one side of the burner unit on the rich flame side to allow the rich flame from the rich flame side to go along. 2. The rich / lean burner according to claim 1, wherein an induction piece for guiding the lean air-fuel mixture from the light-side mixture unit to the adjacent rich air-fuel mixture is provided at the tip of the flame holding plate. 3. The leading hole of the flame holding plate is provided with a guide hole or the like for guiding a part of the light air-fuel mixture from the light-side mixture unit to its own rich air-fuel mixture. Light and dark burning burner. 4. The dense side burner unit and the light side mixture unit are installed so as to be inclined, and the flame holding plate provided in the rich side burner unit is used as the burner port of the rich burner unit or the burner port of the rich burner unit. 2. The rich / lean combustion burner according to claim 1, wherein a discharge port of the light side mixture unit is covered. 5. The flame port forming surface of the rich side burner unit, or the flame port forming surface of the rich side burner unit and the discharge port forming surface of the light side mixture unit are obliquely provided. The described light and dark combustion burner. 6. The rich / lean burner according to claim 1, wherein the rich flame port of the rich burner unit is provided so as to be biased toward the flame holding plate side.