JP2827758B2 - Combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus for burning kerosene, which is used for a water heater or a heater in a home or the like, and more particularly to a structure of a combustion section.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional combustion apparatus of this type is configured such that a carburetor 2 and a combustion section 3 are communicated via a dispersion passage 1, and the combustion section 3 has a dispersion passage. 1, and a plurality of cylindrical secondary air passages 5 are provided between the flame openings 4 and not communicated with the dispersion passage 1. Have been. The secondary air passage 5 is configured such that a plurality of secondary air outlets 6 are opened downstream of the combustion unit 3.

[0003] In the combustion section 3, when the air-fuel mixture 7 sent from the vaporizer 2 is ignited, a flame 8 is formed on the flame opening 4, and secondary air 9 is supplied from a secondary air outlet 6. , Combustion is promoted.

[0004]

However, in the above-mentioned conventional construction, the flame 8 is formed in the divided flame opening 4 to increase the chance of contact with the secondary air, so that the combustion reaction is promoted and the flame temperature is increased. Has risen too much, and the amount of nitrogen oxides in the exhaust gas has increased.

[0005] The present invention has been made to solve the above problems, and has as its object to reduce the amount of nitrogen oxides generated in exhaust gas.

[0006]

In order to achieve the above object, the present invention provides a secondary air passage which divides a primary flame port into a plurality, and a dilution passage which communicates with the secondary air passage. A plurality of secondary air outlets are provided between the secondary air passage and the dilution passage, and a mixture inlet hole larger than the plurality of primary flame openings is provided in the dilution passage from an upstream side of the primary flame opening. In addition, a plurality of secondary flame ports are provided which are opened downstream of the primary flame port.

[0007]

According to the present invention, a lean flame having a low air-fuel mixture concentration is formed in the secondary flame outlet to suppress the combustion reaction, so that the flame temperature is reduced and the nitrogen oxides in the exhaust gas are reduced. It becomes like.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIGS. 1 and 2, reference numeral 10 denotes a cylindrical vaporizer made of a material having good heat conductivity, such as aluminum die casting, into which a heater (not shown) for electric heating is cast.
Blower tube 1 for introducing vaporizing air into the side wall of vaporizer 10
1 is provided, and a supply pipe 12 for supplying liquid fuel to the vaporizer 10 in the blower pipe 11 is inserted.
The other end of the supply pipe 12 is connected to a supply pump 13. An air-fuel mixture outlet 14 is provided at an upper portion of the vaporizer 10, and an air-fuel mixture passage 15 is provided above the vaporizer 14 so as to surround the air-fuel mixture outlet 14 and expand upward. A combustion section 16 is provided downstream of the upper portion of the mixture passage 15. A box-shaped secondary air chamber 17 having an opening only above the combustion unit 16 is provided around the combustion unit 16, the mixture passage 15, and the vaporizer 10. An introduction pipe 19 for introducing air from a blower 18 is provided in a part of the secondary air chamber 17. In addition, a cover 20 is provided around the vaporizer 10 so as to penetrate the blower pipe 11 until the cover 20 comes into contact with the mixture passage 15. An end of the blower tube 11 is opened in the secondary air chamber 17. The combustion unit 16 is communicated with the mixture passage 15,
A group consisting of a large number of primary flame ports 21 constituted by a punching plate or the like is provided.
A plurality of secondary air passages 22 are provided. Both ends of the secondary air passage 22 are opened in the secondary air chamber 17.
A dilution passage 23 is provided above the secondary air passage 22 so as to be adjacent to the primary flame port 21.
A pair is formed on both sides of the secondary flame outlet 21, and is formed as a part integrally formed with the secondary air passage 22 by bending a metal plate. Also, both sides of the primary flame port 21 are bent and extended along the sides of the dilution passage 23 and the secondary air passage 22, and the end 24 is spot-welded with the bottom 25 of the secondary air passage 22 by spot welding or the like. The combustion part 16 is assembled by fixing. Between the secondary air passage 22 and the dilution passage 23, a plurality of 2
A secondary air outlet 26 is provided, and a plurality of mixed air inlets 27 penetrate toward the dilution passage 23 on the upstream side of the primary flame port 21. Further, the total area of the opening of the mixture inlet 27 provided on both sides of the primary flame 21 is made larger than the total area of the opening of the primary flame 21, and the mixture is distributed to the dilution passage 23 with a large amount of the mixture. It is planned to be. A plurality of secondary flame ports 28 are provided in the upper part of the dilution passage 23, and are opened in parallel with the primary flame ports 21 toward the downstream side of the primary flame ports 21. The total area of the opening of the secondary flame port 28 is determined by the total area of the opening of the primary flame port 21 and the mixture inlet 27.
Are larger than the total area of the openings. A part of the primary flame port 21 and the dilution passage 23, which constitute the combustion part 16, in contact with the air-fuel mixture passage 15 is constituted by a secondary air passage 22 and a dilution passage 23. 29 is the primary flame,
30 is a secondary flame and 31 is secondary air.

In the above configuration, a heater (not shown)
When air for vaporization is sent from the secondary air chamber 17 to the vaporizer 10 heated by the air supply via the air supply pipe 11 and the liquid fuel is sent via the supply pipe 12 by the supply pump 13, the vapor of the liquid fuel and An air-fuel mixture formed with air for vaporization flows into an air-fuel mixture passage 15 from an air-fuel mixture outlet 14,
At this time, a part of the air-fuel mixture rises as it is and is ejected from the primary flame port 21 as a rich air-fuel mixture. The other air-fuel mixture flows into the dilution passage 23 from the air-fuel mixture inlet 27, is mixed with the secondary air introduced from the secondary air outlet 26, and is ejected from the secondary flame port 28 as an air-fuel mixture having a low concentration. Here, when a part of the air-fuel mixture ejected from the primary flame port 21 is ignited by an igniter (not shown), the fire is sequentially transferred to the primary flame port 21 and the secondary flame port 28, and the primary flame is fired. 29, a secondary flame 30 is formed, and combustion is continued.

According to the structure of this embodiment, since the opening area of the mixture inlet 27 is made larger than the opening area of the primary flame port 21, most of the mixture becomes lean burn with a low concentration of the mixture, and the combustion reaction takes place. Is suppressed, the flame temperature is reduced, and the nitrogen oxides in the exhaust gas are reduced.
Since the opening area of the secondary flame port 28 is made larger than the opening area of the primary flame port 21, the discharge velocity of the secondary flame during lean burn is reduced to improve the flame holding, and the carbon monoxide and pungent odor are improved. This has the effect of preventing the occurrence of the occurrence. Since the primary flame 29 is formed with the primary flame 29 having a high air-fuel mixture concentration in the primary flame port 21, the surrounding flame is stabilized by the flame holding power and the flame temperature of the primary flame 29, and the secondary flame 30 having a small and low flame temperature is stabilized. At the same time, the flame temperature is adjusted so that the production of carbon monoxide, which is a component in other exhaust gas, is prevented while the production of nitrogen oxides is suppressed. Since the portion of the combustion section 16 that is in contact with the air-fuel mixture passage 15 is constituted by the secondary air passage 22 and the dilution passage 23, only the secondary air is ejected from the secondary flame ports 28 at both ends. There is an effect that the side wall of the mixture passage 15 is cooled to prevent deformation and the like.

[0012]

As described above, in the combustion apparatus of the present invention, a dilution air passage is provided in communication with the secondary air passage which divides the primary flame port, and a large portion of the air-fuel mixture flows into the dilution passage. Since it is mixed with the secondary air to perform lean combustion at the secondary flame outlet, the combustion reaction is suppressed, and the nitrogen temperature in the exhaust gas is reduced by reducing the flame temperature,
In addition, since a stable flame is formed using a part of the air-fuel mixture in the primary flame outlet, the flame holding of lean combustion can be strengthened, and there is an effect that components in other exhaust gas such as carbon monoxide are not deteriorated. .

[Brief description of the drawings]

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

FIG. 2 is a partial plan sectional view of a main part of the apparatus.

FIG. 3 is a sectional view of a main part of a conventional combustion device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vaporizer 11 Blower pipe 12 Supply pipe 14 Mixed-air spout 15 Mixture passage 16 Burning part 17 Secondary air chamber 21 Primary flame opening 22 Secondary air passage 23 Dilution passage 26 Secondary air spout 27 Mixed-air inlet 28 2 Next flame outlet

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Chitonori Aso 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A-3-263501 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) F23D 11/10 F23C 11/00 330 F23C 11/00 329 F23D 11/40

Claims (1)

(57) [Claims] 1. A vaporizer provided with a fuel supply pipe and a vaporizing air blower pipe, a gas mixture outlet provided in a part of the vaporizer, and a gas mixture passage facing the gas mixture outlet. ,
A combustion section provided on the downstream side of the mixture passage, a secondary air chamber provided around the combustion section and the mixture passage, and a porous section forming the combustion section and communicating with the mixture passage. And the primary flame port is divided into a plurality of primary flame ports,
A secondary air passage communicating with the secondary air chamber; a dilution passage communicating with the secondary air passage;
A secondary air outlet communicating with a primary air passage; and a plurality of air-fuel mixture inlet holes provided in a part of the dilution passage and larger than the primary flame port penetrated from an upstream side of the primary flame port. When,
A combustion device comprising a plurality of secondary flame ports provided in a part of the dilution passage and opened downstream of the primary flame port.