JP3025713B2 - Gas burner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas burner used for an absorption refrigerator, an absorption heat pump, a boiler and the like.

[0002]

2. Description of the Related Art In recent years, reduction of nitrogen oxides (hereinafter referred to as NOx) discharged from boilers installed in factories or buildings has become a major issue. And, also in the gas burner provided in the boiler, low NOx of exhaust gas has been an issue.

For example, in a gas burner filed by the applicant of the present invention prior to the filing of the present invention, as shown in FIGS. Forming a plurality of secondary air passages for combustion on the periphery;
Primary air passage 29 for combustion between the outer periphery of gas nozzle 24
And a second flame holding plate 26 formed with
And a burner cone 25 connected to the inner wall of the gas nozzle 24, and the fuel gas is ejected from a gas ejection hole 28 formed at the tip of the gas nozzle 24 so as not to coincide with the secondary air passage 20, thereby achieving a low NOx reduction. I have.

[0004]

When the gas burner shown in the above-mentioned prior art is installed in, for example, a furnace having a small diameter of a combustion furnace and is burned, the fuel gas blown out from the gas blowout hole is used as a secondary air passage for combustion. The flame spreads greatly without being affected by the secondary air flowing out of the furnace, and the flame spreads greatly, hits the furnace wall, and there is a possibility that a gas such as CO may be generated beforehand.

[0005] It is an object of the present invention to suppress the generation of gas and NOx during combustion of a gas burner.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a cylindrical gas nozzle having a substantially conical first flame holding plate at the tip and a plurality of gas ejection holes formed in a peripheral wall. When,
In a gas burner including a second flame holding plate in which the gas nozzle is inserted with a gap provided in a primary air passage for combustion, and a burner cone connected to the second flame holding plate and surrounding the gas nozzle, The flame holding plate is provided with a secondary air passage for combustion at a position on the radiation of the gas ejection hole with respect to the cylindrical gas nozzle.

In the second flame holding plate, a secondary air passage for combustion is provided at a position on the radiation of the gas ejection hole with respect to the cylindrical gas nozzle, and a secondary air passage for combustion deviated from the radiation. With the provision, the generation of NOx from the gas burner is suppressed to a low level.

[0008]

When the gas burner is burning, the first flame holding plate 7 having a conical shape is used.
As a result, the primary air and the mixed gas are inclined and flow outward, and the mixing of the primary gas and the combustion gas flowing out of the gas ejection holes 8 is promoted by the secondary air to promote combustion, and before the flame hits the furnace wall. Then, the combustion is completed, and it is possible to avoid the generation of gas beforehand. Further, by increasing the gas ejection speed, the diffusion of the flame is improved, a thin-film flame is formed, the time at which the flame stays at a high temperature is shortened, and the generation of NOx is suppressed.

A rich flame is formed by secondary air for combustion from a secondary air passage for combustion provided at a position on the gas ejection hole with respect to the cylindrical gas nozzle on the radiation and combustion gas from the gas ejection hole, On the other hand, a lean flame is formed by the combustion secondary air from the combustion secondary air passage deviating from the radiation and the combustion gas from the gas ejection holes. That is, the concentration combustion is performed, the combustion temperature can be lowered, and the generation of NOx is suppressed low.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a low NOx gas burner, and FIG. 2 is a front view of the gas burner shown in FIG.

In FIG. 1 and FIG. 2, a gas burner 1 mixes fuel gas supplied from a gas supply pipe 2 and combustion air supplied from a blower 3 to burn. The gas burner 1 has a cylindrical gas nozzle 4,
It comprises a burner cone 5, a burner flange 5A, a wind box 5B, a pilot burner 6, and the like.

Reference numeral 7 denotes a first conical flame holding plate provided at the tip of the gas nozzle 4. A plurality of pieces having a diameter of, for example, 3 mm are provided near the first flame holding plate 7, that is, at the tip of the gas nozzle 4. The gas ejection holes 8 are formed at equal intervals in the circumferential direction of the nozzle.
Reference numeral 10 denotes a circular second flame holding plate provided at the tip of the burner cone 5. Here, a primary air passage 11A is provided between the gas nozzle 4 and an opening 10A formed in the center of the second flame holding plate 10. 11B is the second flame holding plate 10
The secondary air passages are formed in plural at the periphery of, for example, as shown in FIG. 2, the six secondary air passages 11B coincide with the six gas ejection holes 8 in the gas nozzle circumferential direction.
In other words, the second flame holding plate 10 is provided with the secondary combustion air passage 11B at a position on the radiation of the gas ejection hole 8 with respect to the cylindrical gas nozzle 4.

Numeral 12 denotes a combustion furnace of a regenerator of an absorption refrigerator, for example, provided with the gas burner 1 constructed as described above.
A solution (lithium bromide aqueous solution) chamber is formed around the combustion furnace 12.

When the gas burner 1 configured as described above burns, the primary air flowing out of the primary air passage 11A passes through the inside of the second flame holding plate 10. Then, the primary air flows along the first flame holding plate 7 at an angle substantially equal to the angle of the first flame holding plate 7 and flows outward along with the fuel gas flowing out from the gas ejection holes 8. The mixed gas of the fuel gas and the primary air that has tilted and flowed outward coincides with the secondary air that has flowed out of the secondary air passage 11B, and is further mixed by the secondary air to form a flame. The gas outlet 8 and the secondary air passage 11B
And combustion in the circumferential direction of the gas nozzle, so that combustion is promoted by the secondary air and is completed before the flame hits the furnace wall.

Further, since the gas ejection hole 8 is formed small and the ejection speed of the fuel gas is increased, the fuel gas is rapidly diffused to form a thin film flame.

According to the first embodiment, the gas nozzle 4
The primary air and the mixed gas are inclined by the first flame holding plate 7 provided at the tip of the cylinder and flow outward, and the flow path and the secondary air passage of the fuel gas flowing out from the gas ejection holes 8 are formed. 11B, the mixing is promoted by the secondary air, and the combustion is promoted. As a result, the combustion is completed before the flame hits the furnace wall, and generation of unburned gas such as CO can be prevented.

Further, NOx is easily generated because the combustion is promoted and the completion of the combustion is accelerated, but the diffusion of the flame can be improved by increasing the gas ejection speed, and a thin film flame is formed. The time that the flame stays at a high temperature can be shortened, and as a result, the generation of NOx can be suppressed.

Hereinafter, a second embodiment will be described with reference to FIGS. 3 and 4, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

3 and 4, at the tip of the gas nozzle 4, a first flame holding plate 15 which is, for example, a circular flat plate is provided. The outer diameter of the first flame stabilizer 15 is larger than the inner diameter of the second flame stabilizer 10, that is, the diameter of the opening 10A.
In the vicinity of the first flame holding plate 15 at the tip of the gas nozzle 4,
For example, three gas ejection holes 8 are formed. Reference numeral 11C denotes a secondary air passage for combustion, which is provided on the radiation to the gas nozzle 4 of the gas ejection hole 8. Reference numeral 11D denotes a combustion auxiliary air passage provided at a position off the radiation of the gas ejection holes 8 with respect to the gas nozzle 4. Therefore, the number (three) of the gas ejection holes 8 is half of the total number (six) of the secondary air passage for combustion 11C and the auxiliary air passage for combustion 11D.

During the combustion of the gas burner, primary air (10% to 50% of the whole) flows inside the second flame holding plate 10 along the gas nozzle 4 and flows out of the primary air 11A. The primary air flowing out of the primary air passage 11A is
With the fuel gas flowing out of the fuel tank, the fuel gas changes direction in the outer peripheral direction by the first flame holding plate 15 and flows. The mixed gas of the primary air and the combustion gas coincides with the gas ejection holes 8 in the circumferential direction. The fuel is combusted by the secondary air flowing out of the secondary air passage 11C. At this time, the subdivided flame formed at the tip of the gas ejection hole 8 becomes a combustion flame having a high gas concentration (hereinafter, referred to as a "rich flame"). The split flame which is burned by the secondary air flowing out of both sides of the rich flame, that is, the secondary air passage 11D on both sides of the secondary air passage 11C to which the fuel gas is ejected, is fuel gas diffused and burned by the secondary air. Therefore, a fuel flame having a low gas concentration (hereinafter, referred to as a “light flame”) is obtained. Then, as shown in FIG. 4, the rich flame and the light flame are alternately formed in the circumferential direction of the gas nozzle 4.

According to the second embodiment, the gas outlet 8
Of the secondary air passage 11C and the auxiliary combustion air passage 11
D and the gas nozzle 4 of the gas ejection hole 8
Since the auxiliary combustion air passage 11D is provided between the secondary combustion air passage 11C at a position on the radiation with respect to the above, in other words, at a position deviated from the radiation, the rich flame and the lean flame are arranged in the circumferential direction of the gas nozzle 4. Are formed alternately in
The concentration combustion is performed, and the combustion temperature can be lowered. As a result, the generation of NOx can be suppressed to a low level.

The present invention is not limited to the second embodiment. For example, in a gas bar having a large capacity,
Four or more gas ejection holes 8 are formed in the gas nozzle 4, a secondary combustion air passage 11 </ b> C is provided at a position on the radiation of the gas ejection holes 8 with respect to the gas nozzle 4, and a combustion secondary air passage 11 C is provided at a position off the radiation. Also in the case where the auxiliary air passage is provided, when the gas burner burns, the concentration combustion is performed, so that the generation of NOx can be suppressed similarly to the above embodiment.

[0024]

According to the present invention, there is provided a gas burner constructed as described above, comprising a cylindrical gas nozzle having a substantially conical first flame holding plate at the tip and a plurality of gas ejection holes provided on a peripheral wall. ,
In a gas burner including a second flame holding plate into which a gas nozzle is inserted with a gap provided in a primary air passage for combustion, and a burner cone connected to the second flame holding plate and surrounding the gas nozzle, Since the secondary air passage for combustion is provided in the flame plate at a position on the radiation of the gas discharge hole with respect to the cylindrical gas nozzle, the gas discharge speed from the gas discharge hole is increased, and the primary air is discharged by the first flame holding plate. And the mixed gas flow obliquely outward, and the mixing of the primary air and the secondary air is promoted by the secondary air passage for combustion located on the radiation of the gas ejection hole, and the combustion is promoted, and Even when the inside diameter is small,
The combustion is completed before the flame hits the furnace, and the generation of unburned gas can be prevented. Further, by increasing the gas ejection speed, the diffusion of the flame is improved, and the time during which a thin-film flame is formed and the flame stays at a high temperature can be shortened.
Can be reduced.

In the second flame holding plate, a secondary combustion air passage is provided at a position on the radiation of the gas injection hole relative to the cylindrical gas nozzle, and a combustion auxiliary air passage is provided at a position off the radiation. Since the rich flame having a high gas concentration from the secondary air passage for combustion and the light flame having a low gas concentration from the auxiliary air passage for combustion are formed alternately in the circumferential direction of the gas nozzle. During the combustion of the gas burner, concentration combustion is performed, so that the combustion temperature can be lowered, and as a result, the generation of NOx can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a regenerator and a gas burner according to a first embodiment.

FIG. 2 is a front view of the gas burner shown in FIG.

FIG. 3 is a sectional view of a gas burner according to a second embodiment.

FIG. 4 is a front view of the gas burner shown in FIG.

FIG. 5 is a sectional view of a conventional gas burner.

FIG. 6 is a front view of the gas burner shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas burner 3 Blower 4 Gas nozzle 5 Burner cone 7 First flame stabilizer 8 Gas ejection hole 10 Second flame stabilizer 11A Primary air passage 11B Secondary air passage 11C Secondary air passage 11D Secondary air passage

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F23D 14/02 F23D 14/22 F23D 14/74 F23C 11/00 329-330

Claims (2)

(57) [Claims] A peripheral wall having a substantially conical first flame holding plate at a tip thereof.
A cylindrical gas nozzle provided with a plurality of gas ejection holes,
The gas nozzle is inserted with a gap in the primary air passage for combustion.
A second flame holding plate to be inserted and connected to the second flame holding plate
A burner cone surrounding the gas nozzle;
The gas outlet holes in the second flame holding plate.
Burning to a position on the radiation with respect to the cylindrical gas nozzle
A gas burner characterized by having a secondary air passage for use . 2. A substantially circular first flame stabilizing plate is provided at the end, and is provided on the peripheral wall.
A cylindrical gas nozzle provided with a plurality of gas ejection holes;
The gas nozzle is inserted with a gap in the primary air passage for burning
And a second flame holding plate to be connected and
Gas bar with a burner cone surrounding the gas nozzle
The second flame holding plate is provided with the gas ejection holes.
For combustion on the position on the radiation to the cylindrical gas nozzle
The secondary air passage is located at a position off this radiation for combustion.
An auxiliary air passage is provided, and the secondary air passage for combustion is provided.
Rich flame with high gas concentration from the
Light flame with low gas concentration from the road
A gas burner characterized by being formed alternately in a direction .