JPH0449466Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a diffusion-type radiant gas burner that can be used in ethylene cracking furnaces, ethylene dichloride cracking furnaces, etc., and can achieve stable combustion at a low air ratio. .

BACKGROUND ART Gas burners used in ethylene cracking furnaces and ethylene dichloride cracking furnaces have conventionally been configured to form a flat flame for the purpose of uniform heating. That is, the third
As shown in Figures to Figure 4, a tubular gas burner main body 1 is installed through a furnace wall 2, has a diameter that gradually increases in the direction toward the inside of the furnace 3, and has a closed end 1a, and a closed end 1a. A plurality of slits 1c parallel to the axis are provided at equal intervals around the entire circumference of the tube wall 1b near the section, and the end on the outside 4 side of the furnace has an opening 1d.
Facing d, a gas ejection nozzle 5 is arranged so as to be able to eject gas into the gas burner body 1. The pipe diameter near the opening 1d is narrowed and gas is ejected from the gas injection nozzle 5, thereby causing the gas burner body 1 to
Air is sucked through the opening 1d (or by pressurizing the air) to forcefully feed the gas-air premixture 6 into the gas burner main body 1, and this premixture is jetted out from the slit 1c to flatten the air. Forming a flame, the furnace wall 2
The flame is burned along the inner surface of the flame, and the radiant heat from the flame surface provides heat to the heated tube (not shown).

Problems to be Solved by the Invention In the conventional gas burner as described above, a gas-air premixture is supplied for combustion, so the premixture mixes well with air and has good combustibility.
However, on the other hand, thermal _NO
Problems arise such as flame backfire into the gas burner body 1.

This invention solves the above-mentioned problems with conventional gas burners, suppresses the generation of NO _x ,
The present invention aims to provide a gas burner that can prevent backfire and perform stable combustion at a low air ratio.

Means for Solving the Problems In order to solve the above problems, the present invention is a radiant gas burner consisting of a double pipe with the end inserted into the furnace closed, the inner pipe being the fuel gas introduction flow path,
The annular part between the inner tube and the outer tube is used as an air introduction flow path,
A plurality of rows of gas injection chips are arranged at equal intervals around the entire circumference of the pipe wall near the closed end of the inner pipe, and correspond to the gas injection chips provided on the inner pipe on the pipe wall of the outer pipe. It is characterized in that an air-gas ejection port having a diameter larger than the outer diameter of the gas injection chip is concentrically formed at the location.

Function In the radiant gas burner of the present invention, the fuel gas supplied from the fuel gas introduction channel of the inner pipe is
Air is ejected from the gas injection chip and supplied from the air introduction channel in the annular part between the inner tube and the outer tube,
Part of the mixture is injected into the furnace from the air-gas outlet in the outer tube and burned. However, since the gas injection chip injects only the fuel gas, the pore diameter can be minimized, allowing the gas to The injection flow rate becomes high and there is no backfire, and multiple rows of gas injection chips are provided from near the closed end of the inner pipe to the upstream side of the fuel gas supply, so the amount of injected gas is reduced to the closed end. The closer it is, the more it is, and the more upstream it is, the less it is.The injection gas from the gas radiant heat chip on the closed end side lifts the flame and does not ignite, but the flame is held at the upstream side gas injection chip, resulting in bias combustion and thermal NOx. In addition, the mixture of fuel gas and air is slower than in conventional premixing gas burners, and combustion is also slow and stable _.
The occurrence of is reduced.

Embodiment An embodiment of the present invention will be described based on the drawings.
The radiant gas burner 11 has an inner tube 12 and an outer tube 1.
The inner tube 12 and the outer tube 13 are both closed 12a and 13a at one end 11a. The inner pipe 12 is a fuel gas introduction flow path.
The annular portion 14 between the outer tube 13 and the outer tube 13 is an air introduction flow path. End portion 11 of this radiant gas burner 11
The a side vertically penetrates the furnace wall 15 and is inserted into the furnace interior 16. A plurality of (16 in this embodiment) gas injection chips 17 are erected in multiple rows (3 rows in this embodiment) at equal intervals around the entire circumference of the tube wall 12b near the closed end 12a of the inner tube 12. However, this gas injection chip 17 has a small diameter gas injection hole 17a, and the outer tube 1
It is formed at a height that does not touch the inner wall of No. 3. Pipe wall 13 near the closed end 13a of the outer tube 13
In b, an air-gas outlet 18 having a diameter larger than the outer diameter of the gas injection chip 17 is concentrically bored at a location corresponding to the gas injection chip 17 installed upright on the inner wall 12. . The gas injection chip 17 and the air-gas injection port 18 are arranged such that the gas and air are parallel to the wall surface of the furnace wall 15 or
It is provided so that it ejects toward the wall surface at an angle α of 20° (approximately 15° in this example). The shapes of the gas injection tip 17 and the air-gas injection port 18 may be circular, or may be oval, polygonal, etc. as necessary.

In the above-mentioned radiant gas burner 11, the fuel gas 19 supplied from the fuel gas introduction channel of the inner pipe 12 is ejected from the gas injection port tip 17a of the gas injection chip 17, and is Air 2 supplied from the air introduction channel of the annular portion 14
0 and a part of both are mixed and ejected into the furnace interior 16 from the air-gas ejection port 18 bored in the outer tube 13 21
and burns by forming a flat flame. Since the gas injection hole 17a has a small diameter, the fuel gas 19 ejected from the gas injection chip 17 has a high ejection flow rate, and does not cause flashback even if the burner load fluctuates. Further, a plurality of rows (three rows) of gas injection chips 17 are provided from near the closed end 12a of the inner pipe 12 to the upstream side of the fuel gas 19 supply.
The pore diameters of a are the same, so the amount of injected gas increases as it approaches the closed end 12a, and decreases as it approaches the second flow side.
With the gas injected from No. 7, the flame lifts and does not ignite, and the flame is stabilized toward the upstream side, resulting in overall bias combustion and suppressing the generation of thermal NO _x . Further, the fuel gas 19 and air 20,
The mixing that takes place near the air-gas outlet 18
It is slower than conventional premix gas burners, and does not cause sudden combustion reactions, resulting in slow and stable combustion, which also reduces NO _x generation.
Overall, NO _x was reduced by approximately 50% compared to conventional premix gas burners. And since combustion is slow, low wind pressure and low air ratio combustion can be performed.
The residual oxygen concentration in the combustion exhaust gas was almost 0, and the generation of carbon monoxide was also 0.

Effects of the invention In the radiant gas burner of the invention, a flat flame can be formed and heated uniformly without using premixed gas-air air, there is no flashback, and the combustion is bias combustion. Because it is slow, there are no temperature peaks, reducing the generation of NO _x , and low wind pressure and low air ratio combustion are possible, allowing stable combustion of both fuel gas and air at room temperature without being subject to temperature constraints such as preheating. I can do it.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 1, and FIG.
Fig. 4 shows a conventional example, Fig. 3 is a schematic vertical cross-sectional view,
FIG. 4 is a plan view of the main part. 11...Radiant gas burner, 12...Inner tube, 13...Outer tube, 14...Annular part, 17...Gas injection chip, 18...Air-gas outlet.

Claims (1)

[Scope of utility model registration request] It consists of a double tube with the end inserted into the furnace closed.The inner tube serves as the fuel gas introduction passage, the annular part between the inner tube and the outside serves as the air introduction passage, and the inner tube near the closed end of the inner tube serves as the fuel gas introduction passage. A plurality of rows of gas injection chips are erected at equal intervals around the entire circumference of the tube wall, and at locations corresponding to the gas injection tips provided on the inner tube of the tube wall of the outer tube,
A radiant gas burner characterized in that an air-gas ejection port having a diameter larger than the outer diameter of the gas injection chip is concentrically formed.