JPS60223910A - Structure of gas burner - Google Patents

Abstract

PURPOSE:To fulfill calm combustion by reducing a variation based on a draft in the inside of a furnace, by so constituting the titled burner that a cylindrical flame holder is provided around an injection opening and a stable flame is formed by igniting from the root of the injection opening part of fuel gas. CONSTITUTION:Gaseous fuel 16 is passed through an inner pipe 24A and injected respectively through gas injection openings 17, 18, 19. Air is supplied to a flame holder 20 through air supply openings 21, 22 respectively, mixed with the gaseous fuel to be supplied through the gas injection opening 17 in an air-fuel mixing chamber 25 and premixing of the gaseous fuel and the air is fulfilled. An air vortex 31 is formed at a rear flow of an air stirring plate 26 provided on the tip of the flame holder 20, and an air-fuel mixture vortex 30 is formed at the rear flow of a fuel stirring plate 27 provided on the tip of the flame holder 20 by the air-fuel premixture streamed out of the air-fuel mixing chamber 25 through the fuel stirring plate 27. An appropriate combustible air-fuel mixture is formed on the tip of the flame holder 20 by the air vortex 31 and the air-fuel mixture vortex 30, through which a stable flame is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a gas burner structure, and more particularly to a gas burner structure that reduces draft fluctuations in a flame path in a combustion device such as a boiler that uses gas fuel. .

(Background of the Invention) Conventionally, a gas burner nozzle used in this type of combustion device has a main hole that spouts gas fuel at a certain angle into a main passage;
Similarly, it has a subhole (two or more energized holes are arranged) that ejects gas fuel in a direction perpendicular to the burner axis and toward the burner axis, and the gas fuel supplied from the subhole is provided at the center of the burner. The flame was held on the impeller, which stabilized the flame.

However, in such a gas burner structure,
The gaseous fuel ejected from the main hole and the sub-hole both have a slight ignition delay, which has the disadvantage of causing draft fluctuations in the main passage. In other words, the gas fuel ejected from the main hole has a slight ignition delay because no flame is formed from the base of the gas nozzle, and the main hole flame may be blown away. It is a factor that causes this. In addition, the gas fuel ejected from the sub-holes also suffers a slight ignition delay because a flame is not formed from the base of the gas nozzle, and therefore even if flame holding is performed on the impeller, the flame is not formed near the burner nozzle. The ignition delay caused periodic heat generation fluctuation components, which caused draft fluctuations in the furnace.

(Objective of the Invention) The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, form a stable flame at the base of the gas nozzle, and ensure that the supplied gas fuel has no ignition delay and performs stable combustion. The objective is to provide a gas burner structure that can be used.

(Summary of the Invention) The present invention provides a fuel supply pipe through which gaseous fuel is supplied, 1111 or more nozzles provided at the tip of the fuel supply pipe, and means for supplying combustion air around the nozzles. This gas burner structure is characterized in that a cylindrical frame holder is provided around the gas fuel nozzle, and a part of the nozzle is disposed within the frame holder.

In the present invention, it is preferable that the cylindrical frame holder 2 provided around the nozzle of the fuel supply pipe is provided with an air agitation plate and/or a fuel agitation plate.

These disturbance plates may have any non-streamlined shape to form a vortex in the wake of air or fuel, such as plate-like pieces provided perpendicular to the air or fuel flow. be able to. These disturbance plates may be provided separately or may be provided integrally. The frame holder may allow cooling gas to flow therethrough for cooling the fuel supply pipe.

In the present invention, a part of the gas fuel nozzle of the fuel supply pipe is disposed within the frame holder, which performs premixing of fuel and air within the frame holder, and an air disturbance plate and/or Or to measure early ignition by a fuel disturbance plate.

The air stirring plate or the fuel stirring plate may be provided with slits or openings to generate small vortices in the wake of the flow, further enhancing the stirring effect and alleviating thermal stress.

Hereinafter, the present invention will be explained in more detail with reference to embodiments shown in the drawings.

(Embodiment of the Invention) FIG. 1 is a sectional view of a gas burner structure showing an embodiment of the present invention, FIG. 2 is a plan view in the direction of view A in FIG. 1, and FIG. Detailed sectional view of the gas nozzle part 14,
FIG. 4 is a plan view seen from direction B in FIG. 3. 1 and 2, this burner structure consists of an impeller rod 1 provided on the central axis of a channel wall 15, an impeller 2 provided at its tip, and a primary impeller provided concentrically around the impeller rod 1. Air port 3A and primary air damper 4
A primary air pipe 3 with
and a secondary air port 8, a tertiary register 9 and a tertiary air port 10 provided in an outer tertiary air passage, and a wind box wall 11 provided through the secondary and tertiary air passages. It is mainly composed of a gas fuel supply pipe 13. Above 2
Next register 6. Secondary vane 7 and tertiary register 9 are:
It can be driven externally if necessary. The inside of the wind box 12 is constituted by a wind box wall 11 and a furnace wall 15, to which primary, secondary, and tertiary air are supplied, respectively. The gas fuel supply pipe 13 and the gas nozzle part 14 are connected to the second
As shown in the figure, six pieces are arranged evenly along the circumference.

The gas nozzle part 14 at the tip of the gas fuel supply pipe 13 is composed of an outer tube 24 and an inner tube 24A of the fuel supply tube, as shown in FIG. is provided with gas nozzles 17, 18 and 19, and the outer tube 24 has a large-diameter portion at its tip, which has air supply ports 21 and 22, and also has gas fuel flow and An air stirring plate 26 and a fuel stirring plate 27 are provided in a direction perpendicular to the air flow. A gas mixing chamber 25 is formed in the gap between the large-diameter portion of the outer tube 24 and the inner tube 24A, a gas nozzle 17 of the inner tube 24A is open, and gas nozzles 18 and 19 of the inner tube 24A are for air and fuel, respectively. Disturber plate 2
6 and 27. As shown in FIG. 4, the air and fuel stirring plates 26 and 27 have a plurality of slits 28 and 29 along the circumferential direction.

In the above configuration, combustion air is supplied into the wind box 12 via a fan and a duct (none of which are shown). A part of the combustion air in the wind box 12 is transferred to the primary air damper 4.
The air flows in from the primary air port 3A whose opening area is adjusted, and is supplied into the furnace from the air port 5 at the tip of the primary air supply pipe 3. A part of the other combustion air in the wind box 12 is introduced from the secondary register 6, and after the swirling strength is adjusted by the secondary vane 7, it is supplied into the furnace from the secondary air port 8. Inside the wind box 1
The remaining combustion air of No. 2 is introduced from the tertiary register 9 and supplied into the furnace from the tertiary air port 10. On the other hand, the gas fuel 16 passes through the gas supply pipe 13 and is ejected from the gas nozzle 14 into the furnace. That is, as shown in FIG. 3, the gas fuel 16 passes through the inner pipe 24A and enters the gas nozzles 17, 18 and 19;, 6□14. □. Wah, -Nio 7°?
' 2041m is supplied with air from the air supply ports 21 and 22, respectively, and mixed with the gas fuel supplied from the gas nozzle 17 in the gas mixing chamber 25, thereby achieving premixing of the gas fuel and air. Moreover, in order to cool the gas nozzle part 14, cooling air 23 is passed between the outer pipe and the inner pipe, enters the gas mixing chamber 25, and is similarly mixed with the gas fuel.

Air stirring plate 26 provided at the tip of frame holder 20
Air temperature 31 is formed in the wake, and gas mixing chamber 25
The premixed gas flowing out from the frame holder 20 forms a mixture temperature 30 in its wake by a fuel stirring plate 27 provided at the tip of the frame holder 20 .

An appropriate amount of combustible mixed gas is formed at the tip of the frame holder 20 due to the air temperature 31 and the mixture temperature 30, and a stable flame can be formed. Further, as shown in FIG. 4, by providing slits 28 and 29 in the disturbance plates 26 and 27, many smaller strong vortices can be generated, thereby further stabilizing the flame. Further, by providing such slits 28- and 29, it is also possible to relieve thermal stress on the disturbance plate.

According to the above embodiment, a stable flame can be formed from the base of the gas nozzle portion 14, so flame fluctuations due to drafts in the furnace are reduced, and stable and quiet combustion can be performed.

The present invention is not limited to the above-mentioned embodiments, and various other modifications can be considered. That is, in FIG. 1, the gas nozzle portion 14 may be provided at the primary air port 5 or the secondary air port 8, and the gas nozzle portion 18 and 10 may be provided at the gas fuel supply pipe 13 if only one is provided. (Also, the Harnaro shape can be applied to rectangular shapes other than circular, and the frame holder 2o can also be applied to square shapes other than circular.) In addition, the hone and register provided in the secondary air and tertiary air passages are not only movable, but may also be fixed.
1 and 22 may be omitted depending on the case.

(Effects of the Invention) As described above, according to the present invention, since a stable flame can be formed by igniting the fuel gas from the base of the nozzle, fluctuations due to drafts in the furnace are reduced, and quiet combustion is achieved. be able to. Furthermore, by forming a stable flame, a stable combustion range required for the burner, that is, a large turndown can be achieved. In addition, low N such as exhaust gas mixing
Since flame detection can be performed stably even in the case of Ox combustion, the reliability of burner operation can be increased.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a gas burner structure showing an embodiment of the present invention, FIG. 2 is a ground view of A in FIG. 1, and FIG. FIG. 4 is a view from B in FIG. 3. 1... Impeller rod, 2... Impeller, 3...
Primary air supply pipe, 3A...Primary air port, 4...Primary air damper, 5...Primary air port, 8...Secondary air port, 1o...Third air port , 11... Wind box wall, 12...
- Inside the wind box, 13... Gas fuel supply pipe, 14... Gas nozzle part, 15... Channel wall, 16... Gas fuel, 17
．． 18.19... Gas nozzle, 20... Frame holder, 21.22... Air supply 1], 23... Cooling air, 24... Outer tube, 24A... Inner tube, 25... ...Gas mixing chamber, 26...Air disturbance plate, 27...Fuel disturbance plate, 28.29...Slit, 3o...Mixture temperature. Agent Patent Attorney Takenaga Kawakita

Claims (1)

[Claims] (1) A fuel supply pipe to which gaseous fuel is supplied, one or more nozzles provided at the tip of the fuel supply pipe, and means for supplying combustion air around the nozzles. A gas burner structure characterized in that a cylindrical frame holder is provided around the gas fuel nozzle, and a part of the nozzle is disposed within the frame holder. (2. A gas burner structure according to Claim 1, characterized in that an air disturbance plate and/or a fuel disturbance plate is provided at the tip of the frame holder. (3) Claim 1 or 2) 3. The gas burner structure according to item 2, characterized in that the air disturbance plate and/or the fuel disturbance plate is provided with a suction 1 or an opening.