JP3229481B2 - Concentration combustion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an enrichment burner for burning a rich air-fuel mixture formed at one end thereof. A flat rich burn portion formed with a rich inlet port for introducing combustion air is arranged in parallel at a plurality of intervals, and the lean burn port for burning a light mixture is the rich burn port. A flat lean burn portion provided on the same side end face and having a lean mixing chamber communicating with the lean flame port and a lean air inlet for introducing combustion air into the lean mixing chamber is provided. The lean gas section is formed between adjacent rich burn sections using the rich burn section as a constituent member, and a lean gas conducting path for conducting a fuel gas or a mixture for producing a lean mixture is provided. A fuel gas or air-fuel mixture is injected into the light mixing chamber from an injection port formed in the conduction path; Rich gas supply means for supplying fuel gas, and lean gas supply means for supplying fuel gas to the lean gas passage, combustion air being provided at the rich inlet and the lean air inlet. The present invention relates to a concentration combustion apparatus provided with air supply means for supplying air.

[0002]

2. Description of the Related Art Such a gray-scale combustion apparatus has been conceived in order to lower the combustion temperature of the entire apparatus and to minimize the generation of NOx as a nitrogen oxide. Japanese Patent Application No. 6-3356 filed in U.S. Pat. First, the structure disclosed in Japanese Patent Application No. 6-3356 will be briefly described with reference to FIG.
The rich flame 7 that burns the rich mixture and the light flame 10 that burns the light mixture are alternately arranged to stably burn the rich mixture from the rich flame 7 and maintain the rich flame. By the flame action, a large amount of the lean air-fuel mixture from the lean flame 10 is stably burned, the combustion temperature of the entire apparatus is kept low, and the generation of NOx is reduced. And, the light flame port 1
0, the mixing chamber 11
The fuel air or the air-fuel mixture is ejected from the jet port 20 formed in the lean gas passage 14 and mixed with the combustion air supplied to the fuel gas to generate a lean air-fuel mixture. The structure was to discharge and burn.

[0003]

The lean mixture generated in the lean mixing chamber is a mixture having a large air mixing ratio, in other words, a small amount of combustion gas is mixed with a large amount of combustion air. Therefore, it is important to mix as uniformly as possible. In this regard, in the above-mentioned prior application, the fuel gas or the air-fuel mixture was spouted vigorously and mixed with the combustion air supplied into the lean mixing chamber. There was room for improvement in this point. In short, how to generate a uniform lean mixture is a very important issue in a rich-lean combustion apparatus, and the present invention focuses on the generation of the lean mixture, and a uniform mixture with a structure as simple as possible. It is an object of the present invention to provide a light-and-dark combustion apparatus which can generate and generate NOx as much as possible and can perform stable combustion.

[0004]

In order to achieve this object, a lean-burn combustion apparatus according to the present invention is provided at a position closer to a light-flame port than a light-gas passageway in the light-mixing chamber. The main feature is that an orifice for restricting the flow of the air-fuel mixture is located.

Further, in addition to this main feature, the following configuration is also characterized. The lean gas passage may be located between the rich combustion section and the lean air inlet, and the orifice may be located between the lean gas passage and the rich combustion section. Features. Further, the lean gas passage is provided so as to overlap with the rich combustion portion when viewed from the rich mixture outlet from the rich combustion port, and the orifice is fixedly held in the rich combustion portion, It is also characterized in that the lean gas passage is integrally formed of the same member as the rich combustion section. Further, the orifice is formed of a plate having a large number of holes, and the plate is
It is also characterized by being in contact with the rich combustion sections located on both sides thereof.

[0006]

In other words, according to the main feature of the present invention, at a position closer to the light flame outlet than the light gas passage in the light mixing chamber,
Since the orifice that restricts the flow of the air-fuel mixture in the lean-air mixing chamber is located, the fuel gas and the air-fuel mixture are injected into the combustion air by vigorously ejecting them from the ejection port formed in the lean-gas passage. On the other hand, the air-fuel mixture that has been generated by spouting and mixing is once squeezed by this orifice.
It will spread rapidly. Therefore, the fuel gas and the air-fuel mixture are more uniformly mixed with the combustion air by the rapid diffusion action, and the mixing is further promoted by the action of the turbulence generated by the diffusion. As a result, a large amount of the combustion air is produced. On the other hand, a lean mixture in which the combustion gas is uniformly mixed is generated.

In this case, the lean mixing chamber can be elongated in the flow direction of the lean mixture by positioning the lean gas passage between the rich combustion section and the lean air inlet. By locating the orifice between the lean gas passage and the rich combustion section, the distance from the orifice to the lean burn port can be increased. This makes it possible to rectify the flow of the lean mixture that has been disturbed by passing through the orifice, and to discharge the uniformly mixed lean mixture from the lean flame outlet.

Further, by providing the lean gas conducting passage so as to overlap with the rich combustion portion when viewed from the direction in which the mixture is discharged from the rich flame port, the lean gas passage is provided between the rich combustion portions. The light mixing chamber itself can be formed into a simple shape with little unevenness, avoiding the situation where the conduction path is located. As described above, if there are few things in the lean mixing chamber that hinder the good flow of combustion air, the pressure loss due to ventilation is reduced, and the shape is close to ideal as a lean mixing chamber through which a large amount of combustion air flows. Become.

Further, by fixing the orifice to the rich combustion portion, the orifice can be held with a relatively simple structure. In addition, the lean gas passage is connected to the rich combustion portion. By integrally forming the same member, the structure can be simplified, the manufacturing can be facilitated, and the cost can be reduced. Further, when the orifice is formed from a plate-like body having a large number of holes, the orifice itself can be easily and inexpensively manufactured, and the plate-like body is brought into contact with the rich combustion portions located on both sides. Thus, the orifice can also perform the function of maintaining the interval of the rich combustion portion and the function of reinforcing.

[0010]

As described above, according to the gray-scale combustion apparatus of the present invention, a lean air-fuel mixture in which combustion gas is uniformly mixed with a large amount of combustion air by rapid diffusion and turbulence. Can be generated and discharged from the light flame outlet, and as a result, stable and good combustion can be achieved. In addition, the flow of the lean mixture which is disturbed by the passage through the orifice can be rectified to discharge the lean mixture in an orderly manner, or the lean mixing chamber itself can be made simple to reduce the pressure loss due to ventilation. Further, the orifice that enables cost reduction by simplifying the structure and facilitating the manufacture, and the orifice that enables such uniform mixing can also maintain the interval of the rich combustion portion and perform the reinforcing action. .

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concentration combustion apparatus according to the present invention is used for a burner unit of a hot water supply apparatus, for example. Referring to FIGS. A large number of rich-burning burners 3 as flat rich-burning sections are housed in the inside 2 in parallel at predetermined intervals. Below the burner case 1, a fan 4 as an air supply means for combustion air is located, and a discharge port 4a of the fan 4 is opened at the bottom of the burner case 1, so that the bottom of the burner case 1 An air chamber 5 is formed between the bottom of the frame 2. Thus, by arranging the flat rich burners 3 side by side at predetermined intervals,
A flat space is formed between adjacent burners 3 for rich combustion, and this space is used for forming a burner 6 for light combustion as a light burn portion. In other words, the burner for rich combustion 3 itself is used as a constituent member of the burner for light combustion 6, and by sharing the constituent members, saving of members and simplification of the structure are achieved.

The rich combustion burner 3 has a rich flame port 7 for discharging a rich air-fuel mixture having a low primary air mixing ratio upward,
An enrichment mixing chamber 8 communicating with the enrichment flame port 7, and an enrichment inlet 9 for introducing a fuel gas for generating an enriched mixture and combustion air into the enrichment mixing chamber 8 are formed. . On the other hand, the light burner 6 has a light flame port 10 for discharging a light air mixture having a high primary air mixing ratio upward, a light mixing chamber 11 communicating with the light flame port 10, and a light mixing chamber 11. A light air inlet 12 for introducing combustion air from below into the mixing chamber 11 and the like, and a perforated air conditioning plate 13 forming a bottom wall of the box-shaped frame 2 are formed in the light air inlet 12. Through the air chamber 5
The air for combustion is supplied from the upper side to the upper side.

A lean gas passage 14 for introducing a fuel gas or a mixture for producing a lean mixture into the lean mixing chamber 11 of the burner 6 for lean combustion. The light introduction port 15 for introducing air is separated from the rich mixing chamber 8 and the rich introduction port 9, and the rich combustion port is viewed from the discharge direction of the mixture from the rich flame port 7. Overlapping with the burner 3, the lean gas passage 14 and the lean inlet 15 are closer to the lean air inlet 12 than the rich mixing chamber 8 and the rich inlet 9 in a plate-like shape. The members are integrally formed with the same members as the burners 3 for rich combustion.

The rich inlet 9 of the rich burner 3 and the lean inlet 15 of the light burner 6 are open in the same direction and are close to each other. The fuel gas headers 16 and 17 are located, and the rich fuel gas header 16 located above is provided with a number of rich gas nozzles 18 as an example of rich gas supply means. The gas header 17 is provided with a plurality of light gas nozzles 19, each of which is an example of light gas supply means.

Each of the enrichment gas nozzles 18 faces each of the enrichment inlets 9 and blows fuel gas from the enrichment gas nozzle 18 to enrich combustion air in the air chamber 5 at a predetermined rate by an ejector action. The mixture is sucked into the inlet 9 and mixed in the process of passing through the rich mixture chamber 8 to generate a rich mixture, and this rich mixture is discharged from the thick flame 7. Similarly, each light gas nozzle 19 faces each light inlet 15,
By blowing the fuel gas from the lean gas nozzle 19,
The combustion air in the air chamber 5 is sucked into the lean gas inlet 15 at a predetermined ratio by an ejector action, and is mixed in advance in the passage of the lean gas passage 14, and the mixture is provided in the lean gas passage 14. The mixture is spouted from the plurality of spouts 20 into the light mixing chamber 11. Then, in the light mixing chamber 11,
The lean air-fuel mixture is mixed with the combustion air from the lean air inlet 12 to generate a lean air-fuel mixture, and the lean air-fuel mixture is discharged from the lean flame port 10.

The air-fuel mixture discharged from the light-emission flame port 10 is a light air-fuel mixture having a high air mixing ratio. A problem is how to uniformly mix the air-fuel mixture jetted from the jet port 20 of the light gas passage 14 with the air. In the combustion device of the present invention, in the mixing chamber 11 for lean, the gas passage 10 for the lean gas is closer to the flame opening 10 for the lean, and the mixing chamber 8 and the inlet 9 for the lean are used for the lean mixing. An orifice 21 for restricting the flow of the air-fuel mixture in the lean mixing chamber 11 is located at a position close to the gas passage 14.

The light mixing chamber 1 is connected to the light air inlet 12 through the light mixing chamber 1.
The fuel gas contained in the air-fuel mixture is converted into the combustion air by vigorously ejecting the air-fuel mixture from the ejection port 20 formed in the lean gas passage 14 with respect to the combustion air supplied into the combustion gas supply line 1. On the other hand, some mixing is possible. However, by providing such an orifice 21, the air-fuel mixture which has been mixed to some extent can be further rapidly diffused after being once squeezed. Mixing appears. Moreover, since the orifice 21 is located in the light mixing chamber 11 at a position relatively close to the light gas passage 14, in other words, at a position distant from the light flame port 10, turbulence is generated by diffusion. Even if it occurs, it is rectified while passing through the light mixing chamber 11 and is discharged neatly from the light flame port 10 to enable stable combustion.

As shown in FIG. 4, the orifice 21 includes a single flat plate 22 and a number of round holes 23 formed in the plate. These many holes 23
Are arranged in a row at substantially equal intervals along the longitudinal direction of the light mixing chamber 11, and between each row of the large number of holes 23, in the longitudinal direction of the light mixing chamber 11. Along the slit 24 is formed. These slits 24 terminate in the middle of the light mixing chamber 11 in the longitudinal direction, so that a residual portion 22a exists, and the plate-like body 22 remains integrated by the residual portion 22a.

A projection 25 is formed on the opposite side of the remaining portion 22a of the plate-like body 22, and a slit 26 is formed on each rich combustion burner 3 side. As shown in FIG. The burner 3 for rich combustion is juxtaposed, and the plate-like body 22 is inserted, so that the remaining portion 22a of the plate-like body 22 enters the slit 26 on the side of the burner 3 for rich burn.
2 is inserted into the through hole formed in the box-shaped frame 2 so that the orifice 21 composed of the plate-shaped body 22 and the large number of holes 23 can be positioned in the light mixing chamber 11. Has become.

When the orifice 21 is fixedly held on the burner 3 for rich combustion in this manner, each burner 3 for rich burn enters the slit 24 of the plate-like body 22 in a contact state, and the plate-like body 22 is At the same time as the formation of the orifice 21, the function of maintaining the interval between the burners 3 for rich combustion is also performed.

The uniform light air-fuel mixture thus generated is discharged from the light flame 10 and burned, and the primary air mixing ratio is reduced from the thick flame 7 adjacent to the light flame 10. By discharging and burning a rich mixture that can be stably burned alone, a light mixture can be stably and continuously burned by the flame holding action of the combustion flame of the rich mixture. As a result, stable combustion can be achieved while minimizing the generation of NOx.

The fuel gas header 16 for thickening
Is provided with a rich gas supply passage 27 and a light fuel gas header 1.
The gas supply path 28 is connected to the gas supply path 7, and the total amount of fuel gas to be supplied to the main gas supply path 29 upstream of the branch point of the two gas supply paths 27 and 28 is adjusted. A main gas amount adjusting valve V is provided. The main gas amount adjusting valve V is for adjusting the heating power by changing the supply amount of the fuel gas to the combustion device, and is used when a weak heating power which cannot be adjusted by the main gas amount adjusting valve V is required. Is to burn only a specific rich combustion burner 3 and light combustion burner 6 among a plurality of rich combustion burners 3 and light combustion burners 6 to obtain a desired heating power.

[Other Embodiments] The embodiments of the present invention have been specifically described above. However, various modifications can be made in actual implementation, and examples thereof are listed below.

In the above embodiment, the plate 22 forming the orifice 21 is integrated by leaving the remaining portion 22a. However, the plate 22 may be divided into a plurality of parts. Can also. For example, as shown in FIG. 5 and FIG. 6, a large number of holes 23 are formed in a row in a plate-like body 22 divided into widths substantially corresponding to the intervals between the respective rich combustion burners 3, and the holes 23 are formed substantially in the center. Further, the plate-like members 22 may be divided and fixed to the adjacent burners 3 for rich combustion by spot welding or the like, and the plate-like members 22 may be arranged to face each other. At this time, the plate-like members 22 fixed to the rich combustion burner 3 do not necessarily need to be brought into contact with each other. 22 are brought into contact with the rich combustion burners 3 located on both sides, and the plate-like body 22 can also maintain the intervals between the rich combustion burners 3 as in the previous embodiment.

As shown in FIGS. 7 and 8, a large number of holes 23 are formed in a plurality of plate-like members 22 in a row, and the plate-like members 22 are adjacent to each other. Is fixed to one of them by spot welding or the like.
2 can be carried out by contacting the free end side of the second burner 3 with the other burner 3 for rich combustion.
Thus, the intervals between the rich combustion burners 3 can be maintained.

Further, the orifice 21 does not necessarily need to be the round hole 23, but may be an elongated slit. As an example, as shown in FIGS. 9 and 10, a plate-like body 22 having a bent portion 22b on its free end is fixed to both sides of each burner 3 by spot welding or the like. 3 are arranged side by side at regular intervals, as a result, the slits 23
It is also possible to use the same structure as in the case of a.

In each of the embodiments described above, the structure in which the air-fuel mixture is ejected obliquely upward from the ejection port 20 of the lean gas passage 14 is shown. However, it may be horizontal or obliquely downward, and can be ejected in all directions. The ejection is not limited to the air-fuel mixture. Alternatively, the fuel gas may be directly ejected from the fuel cell 20. Further, in each of the embodiments described above, the bottom wall of the box-shaped frame 2 is provided with the perforated plate 1 for air conditioning.
3, the orifice 21 is expected to have the effect of restricting the flow of the air-fuel mixture in the lean mixing chamber 11 and rectifying the air-fuel mixture. As shown in the figure, the perforated plate 13 for air conditioning as in the past can be eliminated, and the air for combustion can be directly supplied from the air chamber 5 to the air inlet 12 for lean air. Becomes In this case, the structure can be simplified by reducing the number of parts.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is an enlarged right side view sectional view showing an embodiment.

FIG. 2 is an enlarged sectional front view showing the embodiment.

FIG. 3 is a cutaway perspective view showing an embodiment.

FIG. 4 is an exploded perspective view of an essential part showing an embodiment.

FIG. 5 is an exploded enlarged perspective view of a main part showing another embodiment.

FIG. 6 is an enlarged right side sectional view showing another embodiment.

FIG. 7 is an exploded perspective view of a main part showing another embodiment.

FIG. 8 is an enlarged right side view sectional view showing another embodiment.

FIG. 9 is an exploded enlarged perspective view of a main part showing another embodiment.

FIG. 10 is an enlarged right side sectional view showing another embodiment.

FIG. 11 is an enlarged right side sectional view showing another embodiment.

FIG. 12 is an enlarged right side view sectional view showing a conventional structure.

[Explanation of symbols]

 3 Rich Burning Section 4 Air Supply Means 6 Light Burning Section 7 Rich Flame 8 Rich Mixing Room 9 Rich Inlet 10 Light Flame 11 Light Mixing Room 12 Light Air Inlet 14 Light Gas Inlet 18 Rich gas supply means 19 Light gas supply means 20 Spout port 21 Orifice 22 Plate-like body 23 Hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F23D 14/02 F23D 14/08 F23D 14/48 F23D 14/62-14/64 F23C 11/00 329-330

Claims (6)

(57) [Claims] An enrichment opening (7) for burning an enriched mixture is formed at one end surface, and an enrichment mixing chamber (8) communicating with the enrichment opening (7); and an enrichment mixing chamber. A plurality of flat rich combustion sections (3) formed with (8) an enrichment inlet (9) for introducing fuel gas and combustion air are arranged side by side at a plurality of intervals to burn a lean mixture. A light flame outlet (10) is provided on the same end face as the thick flame outlet (7).
0), and a light air inlet (1) for introducing combustion air into the light mixing chamber (11).
2) is formed between the adjacent rich combustion sections (3), using the rich combustion section (3) as a constituent member, and a flat lean combustion section (6) for producing a lean mixture. A lean gas passage (14) for conducting a fuel gas or an air-fuel mixture is provided, and the fuel gas or the air-fuel mixture is discharged from the jet port (20) formed in the lean gas passage (14) to the lean mixing chamber. (11) a fuel gas supply means (18) for supplying a fuel gas to the fuel inlet (9); and a fuel gas to the light gas passage (14). A light gas supply means (19) is provided, and the concentration inlet (9) and the light air inlet (1) are provided.
2) An air-fuel combustion device provided with an air supply means (4) for supplying combustion air to the light-gas mixture passage (1) in the light-mixing chamber (11).
A rich-burn combustion apparatus in which an orifice (21) for restricting the flow of the air-fuel mixture in the lean-mixing chamber (11) is located closer to the lean-flame port (10) than in (4). 2. The lean gas passageway (14) is located between the rich combustion section (3) and the lean air inlet (12), and the orifice (21) is provided with the lean gas passage. The lean-burn apparatus according to claim 1, wherein the lean-burn apparatus is located between the gas passage for use and the rich combustion section. 3. The rich gas passage (14) is provided so as to overlap with the rich combustion section (3) when viewed from the direction in which the mixture is discharged from the rich flame port (7). 3. The apparatus according to claim 2, wherein the orifice (21) is fixedly held in the part (3). 4. The lean-burn combustion apparatus according to claim 3, wherein the lean gas passage (14) is formed integrally with the rich burn portion (3) by the same member. 5. The orifice (21) has a plurality of holes (2).
5. The apparatus according to claim 4, wherein the apparatus comprises a plate-shaped body provided with 3). 6. A light-to-dark combustion apparatus according to claim 5, wherein the plate-like body (22) forming the orifice (21) is in contact with the rich combustion portions (3) located on both sides thereof.