JPH062819A - Low-nox burner - Google Patents

Abstract

PURPOSE:A full primary combustion is carried out between one burner unit and the other burner unit, restrict NOx with a simple and less-expensive structure and prevent clogging of a flame port of each of the burners with dusts. CONSTITUTION:A plurality of burner units 1 are arranged side-by-side with a predetermined spacing therebetween. Each of the burner units 1 is provided with a rich mixture gas chamber 3 for feeding rich mixture gas 2 composed of combustion gas and primary air. Between the adjoining burner units 1 is formed an open space 6 for use in mixing secondary air 4 with the rich mixture gas 2 and producing lean mixture gas 5. A berry part of each of the burner units 1 is provided with an upper communicating hole 13, a lower communicating hole 7 and a guide plate 8 for separating these communicating holes. Between the upper ends of the guide plate 8 is formed a main flame port 10 for use in discharging the lean mixture gas 5, and auxiliary flame ports-12-for discharging the rich mixture gas 2 are formed at both sides of the main flame port 10. At the upper surface of each of the burner units 1 is arranged s short- circuited secondary air discharging port 16 for use in discharging the short circuited secondary air 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas burner installed in various gas appliances such as a water heater and a heater, and more particularly to a low NOx burner configured to suppress harmful NOx (nitrogen oxide). Is.

[0002]

2. Description of the Related Art It is known that all primary combustion is effective for reducing NOx. According to this combustion method, in order to keep the temperature of the flame low, the gas is burned in an air-rich state, so it is difficult to stabilize the flame. Therefore, conventionally, a technique has been proposed in which sleeve fires are formed on both sides of the main flame to stabilize the main flame. For example, in Japanese Laid-Open Patent Publication No. 3-263501 or Japanese Utility Model Laid-Open No. 3-38515, in order to form sleeve fire, the structure of the nozzle is modified, a throat tube is provided on the upstream side of the burner plate, or a fan is used. A technique for partitioning the exit is disclosed. Further, in the conventional plate burner of all primary combustion type, a ceramic plate is often used because the flame becomes small and the burner temperature rises. on the other hand,
As a low NOx burner provided with a press burner unit, conventionally, for example, the technique disclosed in Japanese Patent Laid-Open No. 3-274307 or Japanese Utility Model Laid-Open No. 2-115627 is known, but here, it is arranged in a plurality of rows. A main flame port that forms a main flame and an auxiliary flame port that forms a sleeve flame are provided at the upper end of the installed burner unit.

[0003]

However, the conventional low N
According to the Ox burner, not only the structure of the air supply path is complicated, but also it is necessary to use an expensive ceramic plate. Moreover, since the flame port is provided on the burner unit, dust such as combustion products is generated. Was dropped on the burner and clogged at the flame mouth, and vibration combustion was likely to occur. Therefore, an object of the present invention is to provide a low NOx burner capable of suppressing NOx with a simple and inexpensive structure by performing all primary combustion between the burner unit and the burner unit and preventing clogging of the flame mouth with dust. Especially.

[0004]

In order to solve the above problems, a low NOx burner of the present invention has a plurality of burner units arranged in parallel at a predetermined interval, and each burner unit has a combustion gas and a primary gas. A rich mixture chamber for introducing a rich mixture consisting of air is provided, and an upper communication hole and a lower communication hole for leading out the rich mixture are formed in the abdomen of each burner unit, and an upper communication hole and a lower communication hole are formed. A guide plate for separating and guiding the rich air-fuel mixture is provided, and secondary air is mixed between the adjacent burner units and the burner units to generate a light air-fuel mixture by mixing the secondary air. An open space is provided, and a main flame port that discharges a light air-fuel mixture is formed between the upper ends of the guide plates above the open space, and an auxiliary flame port that discharges a rich air-fuel mixture from the upper communication holes on both sides of the main flame port. Forming the top of each burner unit Short circuit to discharge the short-circuit the secondary air is 2
A secondary air outlet is provided.

According to a second aspect of the invention, the guide plate is provided so as to project higher than the upper surface of the burner unit. Also,
In the third aspect of the invention, the short-circuit secondary air outlet is composed of a lower outlet having substantially the same height as the main flame outlet and the auxiliary flame outlet, and a higher outlet higher than that.

[0006]

In the low NOx burner of the present invention, since the main flame is formed by the light air-fuel mixture discharged from the main flame port, the temperature of the main flame is suppressed and NOx is reduced. On both sides of the main flame, sleeve fire is formed by the rich air-fuel mixture discharged from the auxiliary flame port, and the main flame burns in a stable form without lifting. The short-circuited secondary air discharged from the short-circuited secondary air discharge port on the burner unit splits adjacent flames and flames, completely burns sleeve heat, and stably burns the main flame. Cool to prevent flashback. Therefore, the press of a simple and inexpensive structure does not need to modify the nozzles or use the ceramic plates for the three systems of air supply paths leading to the main flame opening, the auxiliary flame opening, and the short-circuit secondary air discharge opening. Can be formed in the burner, and with this, low NO equivalent to all primary combustion
It becomes possible to construct a burner that exerts the x-effect.
Moreover, since the main flame port is formed between the adjacent burner units, it is possible to drop dust into the main flame port, prevent clogging of the main flame port with dust, and avoid vibration combustion in advance. be able to.

Further, if the guide plate is projected higher than the upper surface of the burner unit, the sleeve fire is continuously formed at the base of the main flame, so that the lift of the main flame is surely prevented and the main flame is further prevented. It can be burned in a stable form and noise is reduced. Further, when the short-circuit secondary air discharge port is composed of the low-level discharge port and the high-level discharge port, the short-circuited secondary air is distributed and discharged from both the high-level discharge port and the low-level discharge port, so the amount of air supplied to the base of the flame. The temperature of the flame as a whole can be lowered by restricting the temperature of the flame and by excessively supplying air to the tip portion of the flame, thereby suppressing NOx more effectively.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show the low NO of the first embodiment.
This shows an x burner, in which a plurality of burner units 1 having a press burner structure are arranged side by side at predetermined intervals. Each burner unit 1 is rich in gas composed of combustion gas and primary air (for example, excess air ratio = 0.3-0.
A rich mixture chamber 3 for introducing the rich mixture 2 of 5) is provided. At the abdomen of each burner unit 1, an upper communication hole 13 and a lower communication hole 7 through which the rich mixture 2 in the rich mixture chamber 3 is drawn out.
Are formed in large numbers. Between the adjacent burner unit 1 and the burner unit 1, the rich air mixture 2 from the lower communication hole 7 is mixed with the secondary air 4 to be air rich (for example, excess air ratio = 1.1 to 1.3). There is provided an open space 6 for generating the light air-fuel mixture 5.

A guide plate 8 for separating and guiding the rich air-fuel mixture 2 from the upper communication hole 13 and the lower communication hole 7 is provided at the abdomen of each burner unit 1 at the same height as the burner unit 1. A main flame port 10 that discharges the light air-fuel mixture 5 to form a main flame 9 is provided between the upper ends of the guide plates 8 above the open space 6, and upper communication holes are provided on both sides of the main flame port 10. An auxiliary flame port 12 is provided for discharging a rich mixture 2 from 13 to form a sleeve fire 11. An introduction pipe 15 for introducing a part of the secondary air as the short-circuit secondary air 14 from the rear end in the longitudinal direction of the burner unit 1 is superposed and fixed on the top of each burner unit 1, and the short-circuit 2 is formed on the upper surface of the introduction pipe 15. Next air 1
A plurality of short-circuit secondary air discharge ports 16 that discharge 4 are provided in the width direction.

The low N of the first embodiment constructed as described above
In the Ox burner, the main flame 9 is formed by the air-rich light air-fuel mixture 5 discharged from the main flame port 10. Therefore, the temperature of the main flame 9 can be suppressed to reduce NOx. Further, the sleeve fire 11 is formed on both sides of the main flame 9 by the rich air-fuel mixture 2 discharged from the auxiliary flame port 12. Therefore, the sleeve flame 11 enables the main flame 9 to be burned in a stable form without lifting. Further, the short-circuit secondary air 14 discharged from the short-circuit secondary air discharge port 16 of the introduction pipe 15 is divided so that adjacent flames and flames do not interfere with each other, and the sleeve flame 11 is completely burned, so that the main flame 9 is removed. The combustion is performed stably, and the upper surface of the introduction pipe 15 is cooled to prevent flashback.

As a result, the nozzles of the three system air supply paths leading to the main flame outlet 10, the auxiliary flame outlet 12, and the short-circuit secondary air outlet 16 are modified as in the conventional case, or a ceramic plate is used. Without doing so, it is possible to form a press burner having a simple and inexpensive structure, and with this, it becomes possible to construct a burner that exhibits a low NOx effect equivalent to that of all primary combustion. Moreover, since the main flame port 10 is formed between the adjacent burner unit 1 and the burner unit 1, dust can be dropped into the main flame port 10 to prevent clogging of the main flame port 10 with vibration. Combustion can be avoided in advance.

FIG. 3 shows a low NOx burner of the second embodiment, in which the guide plate 8 is provided so as to project higher than the upper surface of the burner unit 1. According to this configuration, the guide plate 8 enters the inside of the flame, so that the sleeve fire 11 is continuously formed at the base of the main flame 9. Therefore, the lift of the main flame 9 can be reliably prevented, and the main flame 9 can be burned in a more stable form. As a result, noise is also reduced.

FIG. 4 shows a low NOx burner of the third embodiment, in which the short-circuit secondary air discharge port 16 is the main flame port 1.
0 and the low-level discharge port 16a having the same height as the auxiliary flame port 12,
It is composed of a higher discharge port 16b higher than that. The high-order discharge port 16b is provided at the upper end of the standing piece 17 provided upright on the introduction pipe 15 so that the short-circuit secondary air 14 is discharged toward the tip of the main flame 9. According to this
Since the short circuit secondary air 14 is distributed and discharged from both the high and low discharge ports 16a and 16b, the amount of air supplied to the base of the flame is limited, and excess air is supplied to the tip of the main flame 9. ,
The temperature of the flame as a whole can be lowered, and thus NOx can be suppressed more effectively. In addition, according to this structure, the temperature of the entire flame can be lowered, and accordingly, the excess air ratio of the light air-fuel mixture 5 is 1.0 or less (for example, 0.6 to
It may be set to 1.0).

FIGS. 5 and 6 show a low NOx burner of the fourth embodiment, in which a pair of introducing walls 18 for introducing the short-circuit secondary air 14 from below are provided in the central portion in the width direction of the burner unit 1. Inserted and short-circuited at the upper end Secondary air outlet 1
6 is provided. Also with this configuration, substantially the same operational effects as those of the first embodiment can be obtained.

In addition, the present invention is not limited to the above-described embodiments, and the shapes and configurations of the respective portions can be appropriately modified and embodied without departing from the spirit of the present invention.

[0016]

As described in detail above, according to the invention described in claim 1, the main flame opening and the auxiliary flame opening are provided between the burner unit and the burner unit, and the short circuit 2 is provided on the burner unit. Since the secondary air discharge port is formed, all primary combustion is performed between each burner unit, and NOx is simple and inexpensive structure.
It has an excellent effect of suppressing the clogging and preventing clogging of the flame mouth with dust.

According to the second aspect of the invention, since the guide plate is provided so as to project higher than the upper surface of the burner unit, the main flame can be burned in a more stable form, and the noise is also reduced. .

According to the invention described in claim 3, the short circuit 2
Since the secondary air outlet is composed of the low-level outlet and the high-level outlet, the temperature of the entire flame can be lowered and NOx can be suppressed more effectively.

[Brief description of drawings]

FIG. 1 is a sectional view of a low NOx burner showing a first embodiment of the present invention.

2 is a side view of the low NOx burner of FIG. 1. FIG.

FIG. 3 is a sectional view of a low NOx burner showing a second embodiment of the present invention.

FIG. 4 is a sectional view of a low NOx burner showing a third embodiment of the present invention.

FIG. 5 is a sectional view of a low NOx burner showing a fourth embodiment of the present invention.

6 is a side view of the low NOx burner of FIG.

[Explanation of symbols]

1 ・ ・ Burner unit, 2 ・ ・ Dense mixture, 3 ・ ・ Dense mixture chamber, 4 ・ ・ Secondary air, 5 ・ ・ Light mixture, 6 ・ ・ Open space, 7 ・ ・ Lower communication hole, 8 ・・ Guide plate, 9 ・ ・ Main flame,
10 ・ ・ Main flame mouth, 11 ・ ・ Sleeve, 12 ・ ・ Auxiliary flame mouth, 1
3 ・ ・ Upper communication hole, 14 ・ ・ Short-circuit secondary air, 15 ・ ・ Introduction pipe, 16 ・ ・ Short-circuit secondary air discharge port, 16a ・ ・ Low-level discharge port, 16b ・ ・ High-level discharge port, 17 ・ ・ Standing piece , 18
・ Introduction wall.

Claims (3)

[Claims] 1. A plurality of burner units are arranged side by side at a predetermined interval, a rich mixture chamber for introducing a rich mixture of combustion gas and primary air is provided in each burner unit, and each burner unit is provided with a rich mixture chamber. In the abdomen, an upper communication hole and a lower communication hole for leading out the rich air-fuel mixture are formed, and a guide plate for separating and guiding the rich air-fuel mixture from the upper communication hole and the lower communication hole is provided. An open space is created between the burner unit and the secondary mixture to generate a light air-fuel mixture from the rich air-fuel mixture, and the light air-fuel mixture is discharged between the upper ends of the guide plates above the open space. The main flame opening is formed, and the auxiliary flame opening that discharges the rich air-fuel mixture from the upper communication hole is formed on both sides of the main flame opening, and the short-circuit secondary air that discharges the short-circuit secondary air is provided on the top of each burner unit. Characterized by being provided with an air discharge port Low NOx burner. 2. The guide plate is provided so as to project higher than the upper surface of the burner unit.
Low NOx burner. 3. The short-circuit secondary air outlet is composed of a lower outlet having substantially the same height as the main flame outlet and an auxiliary flame outlet, and a higher outlet higher than the lower outlet. Low NOx burner.