JP2953245B2 - 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 used in 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 divided secondary air passages 5 that are not in communication with the dispersion passage 1 are provided between the porous flame openings 4, respectively. ing. A plurality of secondary air outlets 6 are formed in the secondary air passage 5 so as to be 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 excessively, and as a result, the amount of nitrogen oxides in the exhaust gas has increased, and there has been a problem that the natural environment is deteriorated. In addition, since the plurality of flame outlets 4 and the secondary air passages 5 are connected to each other, the number of assembly steps is increased, and the weight of the combustion device is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to reduce the generation amount of nitrogen oxides in exhaust gas and to simplify the structure of a combustion apparatus. .

A second object of the present invention is to prevent deformation of a combustion chamber wall.

[0007]

In order to achieve the above object, according to the present invention, a flame upper plate having a plurality of projections on the downstream side of the mixing passage and a plurality of depressions on the upstream side are provided. A secondary air passage is formed by connecting the flame bottom plate provided with the portion,
A plurality of mixture inlet holes are provided from the upstream side of the mixing passage, and a plurality of secondary flame ports are provided on the downstream side, and a plurality of primary flame ports are provided between the secondary air passages. Things.

According to a second aspect of the present invention, a plurality of secondary air outlets are provided in the secondary air passage at the end where the mixture flow inlet is not provided in contact with the combustion chamber wall.

[0009]

According to the first aspect of the present invention, there is provided the present invention,
Since a lean flame having a low mixture concentration is formed at the secondary flame outlet and the combustion reaction is suppressed, the flame temperature is reduced and nitrogen oxides in the exhaust gas are reduced. Further, since the burner is constituted by two plates, the upper plate and the lower plate, the combustion device is simplified, and the number of assembling steps and weight are reduced.

In the second aspect, since the air flows along the combustion chamber wall, the combustion chamber wall is cooled, and deformation of the combustion chamber wall due to combustion heat is prevented.

[0011]

An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, 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. On the side wall of the carburetor 10, there is provided a blower pipe 11 through which vaporization air flows, and a supply pipe 12 for supplying liquid fuel to the carburetor 10 in the blower pipe 11. 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 a mixing passage 15 is provided above the vaporizer 10 so as to surround the air-fuel mixture outlet 14. A combustion section 16 is provided above the mixing passage 15.
Is provided.

The combustion section 16, the mixing passage 15, the carburetor 1
A box-shaped secondary air chamber 17 having an opening only above the combustion portion 16 is provided around the periphery of the combustion chamber 16. This secondary air chamber 1
An introduction pipe 19 for introducing air from the blower 18 is provided in a part of 7. Around the evaporator 10, a cover 20 is provided so as to penetrate the blower tube 11 until the cover 20 comes into contact with the mixing passage 15. An end of the blower tube 11 is opened in the secondary air chamber 17.

The combustion section 16 is formed by continuously bending a single plate toward the downstream side of the mixing passage 15 to form a flame upper plate 22 having a plurality of projections 21 provided therein.
5. The flame bottom plate 2 having a plurality of recesses 23 provided by continuously bending one plate toward the upstream side
4. The flame top plate 22 and the flame bottom plate 2
4, a plurality of cylindrical secondary air passages 25 are provided by the protrusions 21 and the recesses 23. Both ends of the secondary air passage 25 are opened in the secondary air chamber 17. In addition, between each of the plurality of secondary air passages 25, there is provided a bonded contact portion 26 between the flame port upper plate 22 and the flame port bottom plate 24. A plurality of primary flame ports 27 are provided.
The projecting portion 21 is provided with an inclined portion 28 such that the space above the bonding portion 26 is gradually enlarged toward the downstream side of the mixing passage 15. A plurality of secondary flame ports 29 having a large opening are also provided. The recess 23 is provided with a plurality of mixture inlets 30 having openings larger than the primary flame port 27. 31
Is a primary flame, 32 is a secondary flame, and 33 is an air-fuel mixture.

In the above configuration, the heater (not shown)
The air for vaporization is sent from the secondary air chamber 17 to the vaporizer 10 heated by the air from the secondary air chamber 17 via the blower pipe 11, and the liquid fuel is sent from the supply pump 13 via the supply pipe 12.
Then, a mixture 33 formed by the vapor of the liquid fuel and the air for vaporization flows into the mixing passage 15 from the mixture outlet 14, and at this time, a part of the mixture rises as it is and the concentration from the primary flame port 27 increases. It is ejected as a rich mixture. The other air-fuel mixture 33 flows from the air-fuel mixture inlet 30 into the secondary air passage 25, is mixed with the secondary air introduced from the secondary air chamber 17, and is ejected from the secondary flame port 29 as a low-concentration air-fuel mixture. You. Here, when an igniter (not shown) ignites a part of the air-fuel mixture ejected from the primary flame port 27, the primary flame port 2
7, the fire is sequentially transferred to the secondary flame port 29, and the primary flame 31, the secondary flame 32 is formed, and the combustion is continued.

According to the configuration of this embodiment, the opening area of the air-fuel mixture inlet 30 is made larger than the opening area of the primary flame port 27. Most of the air-fuel mixture becomes lean burn with a low air-fuel mixture concentration, and the combustion reaction 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 29 is made larger than the opening area of the primary flame port 27, the emission velocity of the secondary flame during the lean combustion is reduced to improve the flame holding, and the carbon monoxide and the stimulation are reduced. Odor generation is prevented.
Since the primary flame 31 having a rich mixture is formed in the primary flame port 27, the surrounding flame is stabilized by the flame holding power and the flame temperature of the primary flame 31 and the secondary flame 32 having a large and low flame temperature is stabilized. At the same time, the flame temperature is adjusted to prevent the generation of carbon monoxide, which is a component in other exhaust gas, while suppressing the generation of nitrogen oxides. Since the flame top plate 22 and the flame bottom plate 24 each composed of a single plate are joined and assembled, the assembly time is reduced, the number of steps is reduced, and the cost is reduced. In addition, since the configuration of the combustion unit 16 is simplified, the weight of the combustion device can be reduced, and the labor for installation can be saved.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 2, the difference from the above-described embodiment is that an opening is formed at an upper portion of an end secondary air passage 35 in contact with a combustion chamber wall 34 formed by a side wall of the secondary air chamber 17 toward the downstream side of the mixing passage 15. Thus, a plurality of secondary air outlets 36 are provided along the combustion chamber wall 34. According to this configuration, the secondary air 37 from the secondary air Since the wall 34 is cooled, deformation due to heat of combustion can be prevented.

[0017]

According to the combustion apparatus of the present invention as described above, the following effects can be obtained.

(1) Since the evaporated fuel is mixed with the secondary air in the secondary air passage to perform lean combustion at the secondary flame port, the combustion reaction is suppressed and the flame temperature is reduced. As a result, nitrogen oxides in the exhaust gas are reduced, and a stable flame is formed in the primary flame using a part of the air-fuel mixture. The components in the exhaust gas do not deteriorate.

(2) Since the flame top plate and the flame bottom plate are joined, the number of assembling steps is reduced, and the weight of the combustion device can be reduced.

(3) Since the combustion chamber wall is cooled by the two o'clock air, deformation of the combustion chamber wall can be prevented.

[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 sectional view of a main part of another embodiment of the present invention.

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 Mixing passage 17 Secondary air chamber 21 Projection part 22 Flame port upper plate 23 Depressed part 24 Flame port bottom plate 25 Secondary air path 27 Primary flame port 29 Secondary flame port 30 mixed air inlet 36 secondary air outlet

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Chinori Aso 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-6-300226 (JP, A) JP-A-6 -129610 (JP, A) JP-A-3-263501 (JP, A) JP-A-2-36716 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F23D 11/40 F23D 11/10 F23C 11/00 329-330

Claims (2)

(57) [Claims] 1. A vaporizer provided with a fuel supply pipe and a vaporizing air blower pipe, an air-fuel mixture outlet provided in a part of the vaporizer, a mixing passage facing the air-fuel mixture outlet, A secondary air chamber provided around the passage, a flame upper plate provided in the middle of the mixing passage and having a plurality of protrusions facing the downstream side of the mixing passage, and a flame upper plate connected to the flame upper plate; A flame bottom plate with a plurality of depressions facing the upstream side of the mixing passage, a secondary air passage composed of the protrusions and the depressions, the ends of which are communicated with a secondary air chamber, A plurality of primary flame ports provided between the secondary air passages and penetrating the flame port upper plate and the flame port bottom plate from an upstream side of the mixing passage; and a part of the secondary air passages A plurality of mixed gas inlets provided upstream of the mixing passage;
A combustion device comprising a plurality of secondary flame ports provided in a part of a secondary air passage and opened downstream of the mixing passage; 2. A combustion chamber wall formed inside a secondary air chamber, and a part of a secondary air passage which is in contact with the combustion chamber wall and is not provided with a mixture inlet, and is provided at a part of the secondary air passage. 2. The combustion apparatus according to claim 1, comprising a plurality of secondary air outlets opened along the combustion chamber wall.