JPH06300230A - Combustion device - Google Patents

Abstract

PURPOSE:To prevent unburnt components from being generated in a large amount and a local lift from being produced by a method wherein air shields which protrude upward are provided along the periphery of a burner to keep secondary air from blowing into burner ports. CONSTITUTION:A thick-fuel mixing section A is composed of a flat rectangular tubular body (a) and air shield plates 15 are attached at both upper edges of the rectangular tubular body (a) to keep secondary air from blowing directly into a burner port 1 through a gap 8. The air shield plates 15 protrude upward beyond a burner port 1. Providing the air shield plates 15 prevents the secondary air from being unnecessarily supplied in excess to thick-fuel flames located at the edges, and stabilizes the combustion state, resulting in a reduction in CO content in the exhaust gas. Flow equalizing plates 14 for thin-fuel mixing sections B, which are provided on both sides of the rectangular tubular body (a), and the air shield plates 14 are integrally made into one body and fixed at the side edges of the rectangular tubular body (a).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus which is constructed so that secondary air for combustion is ventilated upward in a side peripheral portion of a burner in which flame holes are formed.

[0002]

2. Description of the Related Art Conventionally, in this type of combustion apparatus, the peripheral portion of the burner is formed at the same height as the flame holes.

[0003]

However, according to the above-mentioned prior art, since the secondary air is blown directly into the flame formed in the burner, a region of excess air is locally generated, and the unexposed region is not generated. There are inconveniences that a large amount of fuel components (for example, CO and HC) are generated, and local lifts (blowing phenomenon) occur. An object of the present invention is to eliminate the above-mentioned conventional drawbacks.

[0004]

The combustion apparatus according to the present invention is characterized in that a peripheral portion of the burner is provided with a shielding plate for shielding the secondary air from being blown into the flame holes so as to project upward. There is a point.

[0005]

According to the characterizing feature of the present invention, since the shield plate is provided at the peripheral portion of the burner so as to project upward, the secondary air does not blow directly into the flame.

[0006]

According to the characterizing features of the present invention, since the secondary air is not blown directly into the flame, an excessive air region is locally generated and a large amount of unburned components are generated. It is possible to provide a combustion device that solves the inconvenience and the inconvenience of causing local lift.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, secondary air for combustion is ventilated upward to the side peripheral portions of the rich mixing portion A and the light mixing portion B as burners in which the flame holes 1 and 2 are formed. A rich / lean burner is shown as an example of a burner.

In the rich-lean combustion device, a flat rich mixing section A for producing a rich air-fuel mixture having a small primary air suction ratio and a light mixing section B having a large primary-air suction ratio are alternately arranged to provide a rich air-fuel mixture. A rich mixture air flame hole 1 is formed on the upper surface of the portion A, and a light air mixture flame hole 2 is formed on the upper surface of the light mixture portion B. The rich flame of the rich air mixture provides ignitability and flame holding effect. while maintaining, by performing the combustion of desired combustion amount while lowering the combustion temperature by pale flame produced by a light mixture, performing combustion generated is minimized of the NO _X in the exhaust gas (nitrogen oxides) It is a combustion device that can.

The rich / lean combustion device in this embodiment is constituted by a so-called Bunsen burner. The rich mixing section A and the light mixing section B are housed in a casing K in the shape of a square cylinder with a bottom arranged alternately. The rich flame is above the flame hole 1 provided in the rich mixing section A, and the lean flame is the lean mixing section B.
Are formed above the flame holes 2 provided in each. The casing K includes a bottom plate 5, a burner fixing plate 6 as a side wall of the casing K, and a side plate 7. In the bottom plate 5 of the casing K, there are provided a rich mixing supply port 5a and a light mixing supply port 5b corresponding to the rich mixing part A and the light mixing part B, respectively, and an opening area of the light mixing supply port 5b. Is larger than the opening area of the supply port 5a for dense mixing. Below the bottom plate 5, a supply port 5a for deep mixing is provided.
Of concentrated fuel gas for dense mixing, which is provided with an ejection nozzle 3a as an ejecting portion for ejecting fuel gas toward the air, and ejection as an ejecting portion for ejecting fuel gas toward the supply port 5b for light mixing Two light fuel gas supply pipes 4 for light mixing provided with nozzles 4b are provided. Therefore, the supply port 5a and the supply port 5 are provided to the dense mixing section A and the light mixing section B, respectively.
The fuel gas is blown through b, and the primary combustion air is sucked with it.

The casing K for accommodating the rich mixing portion A and the light mixing portion B, and the rich fuel gas supply pipe 3 and the light fuel gas supply pipe 4 are in the shape of a bottomed rectangular tube which forms the combustion chamber of the rich and lean combustion device. It is provided inside the barrel R. At the outer peripheral portion of the casing K, a gap 8 is formed by the barrel R and the casing K.
Are formed. The gap 8 is configured such that the secondary air for combustion is ventilated upward, and the secondary air for combustion is supplied to the flame holes 1 and 2 and, at the same time, the secondary air for combustion is passed. It is configured to cool the casing K by the flow and to block the heat from the casing K with respect to the barrel R.

A fan discharge port 9a of a blower fan 9 for blowing the primary combustion air and the secondary combustion air toward the bottom plate 5 and the gap 8 is provided at the bottom of the barrel R. The fan discharge port 9a is provided with a baffle plate 10 for making the flow velocity distribution of the discharge air more uniform and blowing an equal amount of air to each part in the barrel R. The air conditioning plate 10 is made of punching metal or the like. Further, the air rectifying plate 10 is generally configured so that the opening area for the ventilation air is as large as possible so as not to hinder the air blowing effect of the air blowing fan 9 as much as possible while providing the air conditioning effect. By narrowing the area or providing a plurality of air conditioning plates 10, the air conditioning effect and the air blowing effect of the air blowing fan 9 can be adjusted.

FIG. 2 shows two dense mixing sections A and the two
The light mixing section B formed between the dense mixing sections A of the sheet is shown. The rich mixing portion A is composed of a flat rectangular tubular body a. In the lower part of the rectangular tubular body a, a vertically long rectangular tubular inlet portion 11 is formed for supplying fuel gas and primary air for combustion. The inlet portion 11 is configured to be located above the air supply port 5a formed in the bottom plate 5 of the casing K when the rectangular tubular body a is housed in the casing K. A flat rectangular tube-shaped mixing portion 12 is formed on an upper portion of the inlet portion 11. In the mixing section 12, the fuel gas and the primary air for combustion are mixed. At the center of the mixing section 12, there is provided a throttle section 13 for making the distribution of the air-fuel mixture in the mixing section 12 more uniform.

A flame hole 1 for a rich air-fuel mixture is formed on the upper surface of the rectangular tubular body a. In this embodiment, the flame holes 1 are formed by a set of three elliptical flame holes 1a, and eleven flame holes 1 are provided for one square tubular body a at an appropriate pitch. Therefore, the fuel gas and the combustion primary air, which have been supplied to the inlet portion 11 through the air supply port 5a, rise in the inlet portion 11, are mixed and diffused in the mixing portion 12, and are discharged from the flame hole 1. Forms a rich flame.

A rectifying plate 14 for a light mixing section B, which will be described later, is provided on both side surfaces of the upper portion of the rectangular tubular body a.

Further, on both end edges of the upper surface of the rectangular tubular body a,
A shield plate 15 is provided to shield the secondary air from the gap 8 from directly blowing into the flame holes 1. Shield plate 1
As shown in FIG. 3, the reference numeral 5 is provided so as to project upward from the flame hole 1. By providing the shield plate 15, unnecessary excess air in the rich flame located at the end is prevented, the combustion state is stabilized, and CO in the exhaust gas is reduced. In this embodiment, the current plate 14 and the shield plate 15 are integrally formed and fixed to the rectangular tubular body a at the side end portion of the rectangular tubular body a.

In the light mixing section B, as shown in FIG. 4, a plurality of rectangular tubular bodies a are housed in a casing K in a state in which they are spaced at regular intervals. Formed during. The air supply port 5b formed in the bottom plate 5 of the casing K is provided so as to be located between the rectangular tubular bodies a. Therefore, the fuel gas and the primary air for combustion supplied from the air supply port 5b rise in the light mixing section B while being mixed and diffused in the light mixing section B, and are provided above the light mixing section B. After being rectified by the rectifying plate 14 existing therein, it is discharged from the flame hole 2 for the light air-fuel mixture formed between the upper surfaces of the two rectangular tubular bodies a to form a light flame.

The current plate 14 is a rectangular tubular body a located on both sides.
Both of the above are attached, so that one light mixing section B is provided with two straightening vanes 14. Light mixing section B
In the above, the rectifying plate 14 promotes the mixing of the fuel gas and the primary air for combustion, and prevents the flashback at the time of low input,
In addition, it is configured to have a flame holding effect of light flame. The upper end of the current plate 14 is the upper surface of the rectangular tubular body a, or
It is formed at the same height as the flame hole 2 of the light mixing portion B. The vertical width of the rectifying plate 14 promotes the mixing of the fuel gas and the primary air for combustion in a state where the flow resistance of the air-fuel mixture does not unnecessarily increase, and reduces the noise when the lean flame is burned. Is adjusted and formed.

Further, a plurality of convex portions 14a are formed on the current plate 14, and the projections 14a are abutted against the square tubular body a and the other straightening plate 14 to provide a space between the square tubular body a and the straightening plate 14. Interval of
In addition, it is configured to maintain the space between the straightening vanes 14. The distance between the rectangular tubular body a and the rectifying plate 14 and the distance between the rectifying plates 14 are adjusted to dimensions effective for the rectifying plate 14 to exert a quenching effect (cooling effect) in a lean flame. ing.

The shielding plate 15 which is integrally formed with the flow regulating plate 14 shields the direct blowing of the secondary air into the flame hole 1 and also directly blows the secondary air into the flame hole 2. It is configured to shield.

[Other Embodiments] In the above-described embodiments, the shielding plate 15 is formed integrally with the flow straightening plate 14, but is formed separately from the flow straightening plate 14, and the peripheral portion of the rectangular tubular body a. It may be attached directly to.

The shape, structure, size, etc. of the shielding plate 15 can be appropriately changed. For example, it is possible to adjust the effect of shielding the secondary air by changing the height of the protrusion above the flame hole 1 or 2.

The burner is not limited to the rich mixing portion A and the light mixing portion B in the rich / lean combustion device, but in the present invention, secondary air for combustion is directed upward in the side peripheral portion of the burner in which the flame holes are formed. It can be applied to various combustion devices configured to ventilate.
FIG. 5 shows a shield plate 15 provided in a plate type burner. The flame hole 1 is formed on the upper surface of the flame hole plate C. The secondary air is ventilated upward in the side peripheral portion of the flame hole plate C. The shielding plate 15 is provided so as to surround the flame hole 1 in a state of protruding upward on the peripheral portion of the flame hole plate C.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the configuration of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a perspective view showing the overall configuration of a combustion device.

FIG. 2 is a perspective view showing a burner.

FIG. 3 is a sectional view showing a burner.

FIG. 4 is a sectional view showing a burner.

FIG. 5 is a perspective view showing a burner of another embodiment.

[Explanation of symbols]

 A burner B burner 1 Flame hole 2 Flame hole 15 Shielding plate

Claims (1)

[Claims] 1. A combustion device configured such that secondary air for combustion is ventilated upward in a side peripheral portion of a burner (A, B) in which flame holes (1, 2) are formed. There is a shield plate (1) for shielding the blow-in of the secondary air into the flame holes (1, 2) at the peripheral edge of the burner (A, B).
The combustion device 5) is provided so as to project upward.