JP2002022143A - Liquid fuel combustor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To jet air almost uniformly from a plurality of air supply holes formed on an air chamber around a combustion chamber of a liquid fuel combustor. SOLUTION: A burner 10 comprises an air chamber 43 arranged at the upper end outer periphery of a combustion chamber 22, an air communicating channel 45 connected to the air chamber 43 and a blower 12 for supplying air to the air communicating channel 45. The air chamber 43 comprises a plurality of air supply holes 47 arranged along the extending direction thereof, and the number of holes per area is smaller in the vicinity of the outlet port 45A of the air communicating channel 45 compared with whose in the other regions of the chamber. As a result, it is possible to substantially uniform air quantity jetted out from each air supply hole 47.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid fuel combustion apparatus, and more particularly, to a liquid fuel combustion apparatus for making the amount of air ejected from a number of air holes formed in an air chamber around a combustion chamber substantially uniform. Related to the device.

[0002]

2. Description of the Related Art Conventionally, a burner 50 as shown in FIGS. 4 and 5 has been known as a liquid fuel combustion device used for a water heater or the like. The burner 50 has a substantially circular combustion chamber 60 in a plan view, in which fuel such as kerosene burns, a duct-shaped air chamber 70 arranged along the outer peripheral edge of the upper end of the combustion chamber 60, and an outer periphery of the air chamber 70. An air communication passage 72 connected to the air passage 70 and a blower 74 connected to the air communication passage 72 and supplying air to the air chamber 70 are provided. Above the burner 50, a heat exchanger 76 that opens toward the combustion chamber 60 is arranged.
Numeral 6 heats water in the heat exchange pipe 78 wound around the outside of the combustion space S using the combustion heat generated in the combustion chamber 60. Here, at the upper end of the air chamber 70, a large number of air supply holes 80 are formed at equal intervals along the outer periphery of the combustion chamber 60, and air from the blower 74 flows upward from each of the air supply holes 80. It is gushing toward. The ejected air forms an air layer along the inner wall surface 76A forming the combustion space S, and thereby the inner wall surface 76A
It is possible to prevent the dew condensation at the winding part of the heat exchange pipe 78 in A.

[0003]

However, in the burner 50, since the air supply holes 80 are provided at equal intervals along the outer circumference of the combustion chamber 60, the discharge of the air communication passage 72 is prevented. The amount of air ejected from the air supply hole 80 located near the outlet 72A is relatively larger than that of the air supply hole 80 located away from the discharge port 72A. As a result, the amount of air ejected from the air supply hole 80 apart from the discharge port 72A becomes relatively small, and the inner wall surface 76
There is a disadvantage that the condensation of A cannot be sufficiently prevented. In addition, since the amount of air ejected from each of the air supply holes 80 is not uniform, a partial temperature difference occurs in the heat exchange portion, which causes a decrease in heat efficiency or a decrease in durability of the heat exchanger. It becomes a factor to make it. In particular, in a burner (see Japanese Patent Application No. 2000-180041) having a substantially flat combustion chamber in plan view, which has already been proposed by the present applicant, a burner having a substantially circular combustion chamber in plan view is more preferable. In addition, the air supply hole is formed at a position farther from the discharge port of the air communication passage, and the above-mentioned inconvenience becomes more apparent.

[0004]

SUMMARY OF THE INVENTION The present invention has been devised in view of such inconvenience, and its object is to substantially reduce the amount of air ejected from a number of air supply holes formed in an air chamber around a combustion chamber. An object of the present invention is to provide a liquid fuel combustion device that can be made uniform.

[0005]

In order to achieve the above object, a combustion chamber is provided on the heat exchanger side, and air supplied from a blower to the air chamber via an air communication passage is formed in the air chamber. In the liquid fuel combustion device capable of forming an air layer along an inner wall surface forming a combustion space of the heat exchanger by ejecting the air from a large number of air supply holes, an air supply hole area ratio in a region near a discharge port of the air communication passage is provided. Is set lower than the area outside the area near the discharge port. According to such a configuration, since the area ratio of the air supply hole in the region near the discharge port of the air communication passage is set lower than that in the other region, sufficient air can be supplied from the air supply hole at a position distant from the region near the discharge port. And the amount of air ejected from each air supply hole can be made substantially uniform.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is also applicable to those having a combustion chamber which is substantially flat in plan view. Thus, even when a combustion chamber that is substantially flat in plan view is employed, the amount of air ejected from each air supply hole can be made substantially uniform.

[0007] In the present specification, the term “flat” refers to a rectangular shape, an elliptical shape, an oval shape, a rhombic shape,
As exemplified by the same gourd shape, it is used as a concept including a shape having a long direction and a short direction in a plan view, and is used as a concept excluding a shape such as a perfect circular shape in a plan view and the same regular n-gon shape. .

[0008] The "air supply hole area ratio" means the ratio of the total air supply hole opening area per unit area on the upper end surface of the air chamber, which is the air supply hole formation site. Note that the “unit area” here means a plurality of air holes (preferably a few air holes) in a region where the air holes are the densest or a region where the air holes having the largest opening area per one exist. ) (See FIG. 2).

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic perspective view of a burner as a liquid fuel combustion apparatus according to the present embodiment, and FIG.
FIG. 2 shows a schematic plan view of FIG. 1. FIG. 3 is a sectional view taken along line AA of FIG. In these figures, the burner 10 includes a combustion unit 11 for burning liquid fuel such as kerosene, and a blower 12 provided below the combustion unit 11 to supply air to the combustion unit 11. I have.

The combustion portion 11 includes a bottomed square tubular combustion chamber outer cylinder 14 located outside, a bottomed square cylindrical combustion panel 15 provided inside the combustion chamber outer cylinder 14, and a combustion panel 15. Bell-shaped vaporizing cylinder 16 rotatably provided at the approximate center of the inside
And a scattering ring 18 provided below the vaporizing cylinder 16.
And an ignition device 20 extending near the vaporization cylinder 16. Here, the internal space of the combustion plate 15 excluding the vaporization cylinder 16 functions as a combustion chamber 22 for burning liquid fuel, and the combustion chamber 22 has a substantially rectangular shape having a longitudinal direction and a lateral direction in plan view. ing.

In the combustion chamber 22, after the liquid fuel is ignited and the spray combustion is performed, the mixture obtained by mixing the vaporized liquid combustion with the air is ignited so that the vaporized combustion is performed. Has become. That is, at the time of startup, the liquid fuel supplied from the fuel supply pipe 32 is scattered from the gap C between the vaporizing cylinder 16 and the scattering ring 18 by the rotation of the vaporizing cylinder 16, and the scattered liquid fuel is ignited. The fuel is ignited by the device 20 to perform spray combustion. Then, the vaporization cylinder 16 is heated by the combustion heat, the liquid fuel in the vaporization cylinder 16 is vaporized, and the vaporized fuel is supplied to the blower 12.
Mixed with air from This air-fuel mixture passes through a gas chamber 25 between the combustion plate 15 and the outer cylinder 14 of the combustion chamber, and passes through the combustion plate 15.
Are sprayed from the large number of flame holes 26 formed in the combustion chamber, thereby shifting from the initial spray combustion to the vaporization combustion.

Outside the upper peripheral edge of the combustion chamber 22, a rectangular cylindrical air chamber 43 is arranged along the outer peripheral edge. The air chamber 43 includes a pair of longitudinal portions 43A extending in the longitudinal direction in a plan view, and a pair of short portions 43B connecting both ends of the longitudinal portion 43A. here,
An air communication passage 45 connected to the blower 12 is connected to a substantial center of one longitudinal portion 43A located at a lower part in FIG. Therefore, the air from the blower 12 is also supplied to the inside of the air chamber 43 through the air communication passage 45. Further, on the upper end surface of the air chamber 43, a number of air supply holes 47 are formed along the extending direction of the air chamber 43, so that the air in the air chamber 43 can be ejected upward. I have. The number of the air supply holes 47 per unit area in a region near the discharge port 45A of the air communication passage 45 is smaller than that in other regions. Specifically, each air hole 4
7 have the same opening area, and the air supply holes 47 located in a region near the discharge port 45A of the air communication passage 45 are provided at equal intervals at a predetermined wide pitch, while being outside the vicinity region. The located air supply holes 47 are provided at equal intervals at a smaller pitch than the neighboring region. In other words, the area ratio of the air supply holes in the vicinity area is set lower than that in the area outside the vicinity area.
It is provided so that the amount of air ejected from 7 is substantially uniform.

The combustion chamber 2 is located above the burner 10.
A heat exchanger 48 opening to the two sides is arranged. The heat exchanger 48 includes a heat exchange pipe 49 wound around the outside of the combustion space S, so that water flowing in the heat exchange pipe 49 can be heated by combustion heat generated in the combustion chamber 22. I have. Here, when air is ejected upward from a large number of air supply holes 47 formed in the air chamber 43, the combustion space S
An air layer is formed between the inner flame and the inner wall surface 48A that forms the combustion space S, that is, an air curtain is formed along the inner wall surface 48A, and the air-curing portion of the heat exchange pipe 49 on the inner wall surface 48A is formed. Dew condensation will be prevented.

Therefore, according to such an embodiment, since the amount of air jetted upward from the air supply hole 47 is substantially uniform in the entire region, the air supply hole 47 remote from the discharge port 45A of the air communication passage 45 is provided. Air can be spouted from the
The effect is obtained that the dew condensation on the upper inner wall surface 48A can be prevented. In addition, the temperature distribution along the circumferential direction of the heat exchanger 48 can be made uniform, so that a reduction in thermal efficiency can be prevented, and the effect of improving the durability of the heat exchanger can be obtained.

In the above embodiment, the number of air holes 47 per unit area is reduced to reduce the air hole area ratio. However, the present invention is not limited to this. May be smaller than the other air supply holes 47. Further, while the air holes 47 have the same opening area, the pitch of the air holes 47 may be gradually narrowed as the air holes 47 are separated from the vicinity of the discharge port 45A of the air communication passage 45.

Further, in the present invention, it is sufficient that at least a portion of the air chamber 43 that faces the discharge port 45A of the air communication passage 45 has a lower air supply area ratio than the other portions.

Further, in the above embodiment, the combustion chamber 22
The shape of the shape is a substantially rectangular shape in a plan view, but the present invention is not limited to this, and other flat burning shapes such as a substantially oval shape, a elliptical shape, a rhombic shape, and a gourd shape in plan view are exemplified. The present invention may be applied to a burner having a combustion chamber, or may be applied to a burner having a combustion chamber having a substantially circular shape in plan view.

[0019]

As described above, according to the present invention,
Since the air hole area ratio in the area near the discharge port of the air communication passage is set lower than in other areas, air can be sufficiently blown out from the air holes outside the area near the discharge port, and the air is blown out from each air hole. The amount of air to be supplied can be made substantially uniform.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a burner according to an embodiment.

FIG. 2 is a schematic plan view of FIG.

FIG. 3 is a vertical sectional view taken along the line AA in FIG. 2;

FIG. 4 is a schematic plan view of a burner according to a conventional example.

FIG. 5 is a schematic sectional front view of a burner according to a conventional example.

[Explanation of symbols]

10 ... burner (liquid fuel combustion device), 12 ...
Blower, 22 combustion chamber, 43 air chamber, 45
..Air communication passage, 45A discharge port, 47 air supply hole, 48 heat exchanger, 48A inner wall surface, S ..
・ Combustion space

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23D 11/08 F23D 11/08 C 11/40 11/40 A

Claims (2)

[Claims] 1. A combustion chamber having a combustion chamber open to a heat exchanger side, and air supplied from a blower to an air chamber via an air communication passage is blown out from a number of air holes formed in the air chamber. In a liquid fuel combustion device capable of forming an air layer along an inner wall surface that forms a combustion space of a heat exchanger, an air communication hole area ratio in a region near a discharge port of the air communication passage is larger than a region outside the region near the discharge port. A liquid fuel combustion device characterized by being set low. 2. A combustion chamber having a substantially flat combustion chamber open to the heat exchanger side and having a plurality of air holes formed in the air chamber for supplying air supplied from the blower to the air chamber via an air communication passage. In the liquid fuel combustion apparatus capable of forming an air layer along an inner wall surface forming a combustion space of the heat exchanger by ejecting the air from the heat exchanger, the air communication hole area ratio in a region near a discharge port of the air communication passage is equal to the discharge port. A liquid fuel combustion device, which is set lower than a region outside the vicinity region.