JP2006250431A - Burner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a burner capable of preventing a blowout nozzle from having red heat and improving its durability. <P>SOLUTION: This burner 1 has an outer pipe 2 through which first fluid F1 passes, and an inner pipe 3 which is inserted into the outer pipe 2 and in which second fluid F2 passes. The inner pipe 3 has a flange portion 31 projecting to an outer portion in the radial direction R at its tip portion, and the blowout nozzle 4 mounted on a tip side of the flange portion 31. The flange portion 31 has a plurality of blowout grooves 32 for blowing out the first fluid F1. The blowout grooves 32 are formed by forming an inlet opening portion 321 of the first fluid F1 formed on a surface of a rear end portion side of the flange portion 31 and an outlet opening portion 322 of the first fluid F1 formed on a surface of a tip portion side of the flange portion 31 in a state of being shifted from each other in the circumferential direction, and a width of the radial direction R of the outlet opening portion 322 is smaller than a width in the radial direction R of the inlet opening portion 321. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a burner having an outer pipe through which a first fluid passes and an inner pipe through which a second fluid passes.

As the burner for heating the inside of the heating furnace or the like by combustion, for example, as shown in FIG. 4, an outer pipe 92 through which an air-fuel mixture G of fuel gas and combustion air is passed and ejected is inserted into the outer pipe 92. There is a burner 9 having an inner pipe 93 through which the fuel gas F is ejected. The inner pipe 93 has a flange portion 931 that protrudes outward in the radial direction at the distal end portion thereof, and a fuel gas F ejection nozzle 94 that is disposed on the distal end side of the flange portion 931. The flange portion 931 is formed with a plurality of ejection holes 932 for ejecting the air-fuel mixture G.
The air-fuel mixture G ejected from the plurality of ejection holes 932 is combusted to form a pilot flame H, and the fuel gas F ejected from the ejection nozzle 94 is combusted using the pilot flame H as an ignition source. .

  However, in the conventional burner 9, the air-fuel mixture G is ejected in parallel with the axial direction L of the burner 9, and the pilot flame H is formed in parallel with the axial direction L of the burner 9. For this reason, the pilot flame H is formed near the ejection nozzle 94, and the ejection nozzle 94 is heated and reddened, which is not sufficient for improving the durability.

  For example, Patent Document 1 discloses a gas burner in which an intermediate pipe through which primary air flows is inserted into an outer pipe through which fuel gas flows, and an inner pipe through which premixed gas flows is inserted into the intermediate pipe. And in patent document 1, the pilot flame by premixed gas is formed in the center part of a gas burner. Further, the primary air ejected from the intermediate pipe can be combusted with the fuel gas to prevent the main flame from being lifted, and the combustion exhaust due to the combustion of the fuel gas can be prevented from being mixed into the premixed gas.

  However, the gas burner disclosed in Patent Document 1 forms a pilot flame at the center thereof, and burns by injecting fuel gas around the pilot flame. For this reason, no attempt has been made to suppress the red heat of the gas nozzle.

JP-A-6-117612

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a burner capable of suppressing redness of the burner nozzle and improving its durability.

The present invention relates to a burner having an outer pipe that allows passage of a first fluid and an inner pipe that is inserted into the outer pipe and allows passage of a second fluid.
The first fluid is fuel gas or a mixture of fuel gas and combustion air,
The inner pipe has a flange portion that protrudes radially outward at the tip portion thereof, and a jet nozzle that is disposed on the tip side of the flange portion and jets the second fluid,
The flange portion has a plurality of ejection grooves for ejecting the first fluid, and the ejection grooves are formed with an inlet opening portion of the first fluid formed on a surface on the rear end side of the flange portion. The outlet opening of the first fluid formed on the front end side surface of the flange portion is formed at a position shifted in the circumferential direction, and the radial width of the outlet opening is set to the inlet The burner is characterized in that it is formed smaller than the radial width of the opening (claim 1).

The burner of the present invention has a double pipe structure of the outer pipe and the inner pipe, and is devised in the shape of a plurality of ejection grooves formed in the flange portion of the inner pipe.
That is, the ejection groove has an inlet opening through which the first fluid flows in and an outlet opening through which the first fluid flows out at positions shifted in the circumferential direction, and in the radial direction of the outlet opening. The width is formed smaller than the radial width of the inlet opening.

  The first fluid passing through the outer pipe collides with the flange portion, flows into the ejection groove from the inlet opening, and rotates in the circumferential direction and radially outward when passing through the ejection groove. It flows toward. Thus, when the first fluid is ejected from the outlet opening, the first fluid becomes a swirling flow spreading obliquely outward.

Therefore, when the first fluid is combusted, it is possible to suppress the flame formed by the combustion from colliding with the ejection nozzle.
Therefore, according to the burner of the present invention, redness of the burner nozzle can be suppressed and its durability can be improved.

A preferred embodiment of the present invention described above will be described.
In the present invention, the second fluid may be fuel gas, a mixture of fuel gas and combustion air, or combustion air.
Moreover, it is preferable that the front-end | tip surface of the said outer side pipe protrudes rather than the surface by the side of the front-end | tip part of the said flange part in the said inner side pipe (Claim 2).
In this case, the flame caused by the combustion of the first fluid can be formed by colliding with the inner peripheral surface at the tip of the outer pipe. Therefore, it is possible to improve the flame holding property (performance for stably holding the flame) of the flame.

Hereinafter, embodiments of the burner according to the present invention will be described with reference to the drawings.
As shown in FIGS. 1 to 3, the burner 1 of this example includes an outer pipe 2 that allows the first fluid F1 to pass therethrough and an inner pipe 3 that is inserted into the outer pipe 2 and allows the second fluid F2 to pass therethrough. Yes.
The first fluid F1 in this example is a mixture of fuel gas and combustion air, and the second fluid F2 is fuel gas.

  Moreover, as shown in FIGS. 1 to 3, the inner pipe 3 includes a flange portion 31 formed to protrude outward in the radial direction R at the distal end portion thereof, and a second portion disposed on the distal end side of the flange portion 31. And an ejection nozzle 4 for ejecting the fluid F2. The flange portion 31 has a plurality of ejection grooves 32 for ejecting the first fluid F1.

The ejection groove 32 includes an inlet opening 321 of the first fluid F1 formed on the surface 301 on the rear end side of the flange portion 31 and an outlet of the first fluid F1 formed on the surface 302 on the tip end side of the flange portion 31. The opening 322 is formed at a position shifted in the circumferential direction C. Further, the ejection groove 32 is formed such that the radial width R2 of the outlet opening 322 is smaller than the radial width R1 of the inlet opening 321.
The front end side means the downstream side of the flow of the first fluid F1 and the second fluid F2, and the rear end side means the upstream side of the flow of the first fluid F1 and the second fluid F2. Say.

Below, it explains in full detail about the burner 1 of this example.
As shown in FIGS. 1 to 3, the plurality of ejection grooves 32 are formed by connecting the inlet opening 321 and the outlet opening 322 toward one side in the circumferential direction C of the flange 31. Inclined. The air-fuel mixture ejected from each of the ejection grooves 32 can be ejected as a swirl flow swirling around the axial direction L of the burner 1.
As shown in FIGS. 2 and 3, the inlet opening 321 of this example is formed over the entire length in the radial direction R from the inner peripheral end 303 to the outer peripheral end 304 on the surface 301 on the rear end side of the flange portion 31. Has been. Further, the outlet opening 322 is notched from the outer peripheral end 304 on the front surface 302 of the flange portion 31.

Further, a spark rod (not shown) for generating a spark is disposed between the outer pipe 2 and the inner pipe 3. 1 and 2, the air-fuel mixture as the first fluid F1 is ignited by the spark generated from the spark rod, and the pilot flame H is formed. The pilot flame H can be used as an ignition source when the fuel gas as the second fluid F2 ejected from the ejection nozzle 4 is combusted with the combustion air around the burner 1.
Further, the distal end surface of the outer pipe 2 protrudes from the front end surface 302 of the flange portion 31 of the inner pipe 3, and is configured to hold the pilot flame H.

As shown in FIGS. 1 and 2, the flange portion 31 of the inner pipe 3 closes most of the tip end portion of the outer pipe 2. In addition, a plurality of protrusions 33 for facilitating insertion of the flange portion 31 into the outer pipe 2 are formed on the outer periphery of the flange portion 31 of this example. A slight gap is formed by a plurality of protrusions 33 between the flange portion 31 and the inner peripheral surface of the outer pipe 2.
Moreover, the fuel gas of this example is natural gas (city gas 13A), and the combustion air is fresh air.

As shown in FIG. 1, the ejection nozzle 4 of this example has a diameter of φ8 to 16 mm in order to increase the ejection distance of the fuel gas as the second fluid F2 and to form a main flame by combustion of this fuel gas far away. One fuel injection port 41 having the above is formed.
The fuel gas ejected from the ejection nozzle 4 can be combusted with the combustion air around the outer pipe 2 and the inner pipe 3 to form a main flame.

In this example, when the pilot fluid H is formed by burning the first fluid F1, the first fluid F1 is passed through the outer pipe 2.
At this time, the first fluid F <b> 1 passing through the outer pipe 2 collides with the flange portion 31, flows into the ejection groove 32 from the inlet opening 321, and passes through the ejection groove 32 in the circumferential direction. It turns around C and flows outward in the radial direction R. Thereby, when the 1st fluid F1 is ejected from the exit opening part 322, it turns into a swirling flow which spreads toward diagonally outward.

Therefore, when the pilot fluid H is formed by burning the first fluid F <b> 1, the pilot flame H can be prevented from colliding with the ejection nozzle 4.
Further, the pilot flame H is formed by colliding with the inner peripheral surface at the tip of the outer pipe 2. Therefore, the pilot flame H formed by burning the first fluid F1 can be stably maintained.
Therefore, according to the burner 1 of this example, the red hotness of the ejection nozzle 4 can be suppressed, its durability can be improved, and the flame holding property of the pilot flame H can be improved.

FIG. 4 shows the formation state of the pilot flame H in the conventional burner 9, and FIG. 1 shows the formation state of the pilot flame H in the burner 1 of this example. As can be seen from both figures, in the conventional burner 9, the pilot flame H may come into contact with the ejection nozzle 94, so the ejection nozzle 94 becomes red-hot and it is difficult to improve its durability. there were.
On the other hand, according to the burner 1 of this example, the pilot flame H hardly contacts the ejection nozzle 4, and it turns out that the red hot of the ejection nozzle 4 can be suppressed and the durability can be improved.

Cross-sectional explanatory drawing which shows the principal part of the burner in the Example seen from the side. It is a figure which shows the principal part of a burner in the Example seen from the axial direction, and is AA arrow line cross-section explanatory drawing in FIG. The perspective explanatory drawing which shows the formation state of the ejection groove | channel in the flange part in an Example. Cross-sectional explanatory drawing shown in the state which looked at the principal part of the burner in the prior art example from the side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Burner 2 Outer pipe 3 Inner pipe 31 Flange part 301 Rear end side surface 302 Front end side surface 32 Injection groove 321 Inlet opening 322 Outlet opening 4 Injection nozzle F1 First fluid F2 Second fluid H Pilot flame L Axial direction C Circumferential direction R Radial direction

Claims (2)

In a burner having an outer pipe that allows passage of a first fluid and an inner pipe that is inserted into the outer pipe and allows passage of a second fluid;
The first fluid is fuel gas or a mixture of fuel gas and combustion air,
The inner pipe has a flange portion that protrudes radially outward at the tip portion thereof, and a jet nozzle that is disposed on the tip side of the flange portion and jets the second fluid,
The flange portion has a plurality of ejection grooves for ejecting the first fluid, and the ejection grooves are formed with an inlet opening portion of the first fluid formed on a surface on the rear end side of the flange portion. The outlet opening of the first fluid formed on the front end side surface of the flange portion is formed at a position shifted in the circumferential direction, and the radial width of the outlet opening is set to the inlet A burner characterized in that it is formed smaller than the radial width of the opening.   2. The burner according to claim 1, wherein a front end surface of the outer pipe protrudes from a front end side surface of the flange portion of the inner pipe.

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