JP6726476B2 - Surface burning burner - Google Patents

Description

The present invention relates to a surface combustion burner that burns fuel gas and combustion air in a mixed manner on the surface of a breathable member.

There are various burners that form a flame by the combustion of fuel gas and combustion air. Among them, as a surface combustion burner for mixing and burning the fuel gas and the combustion air on the surface of the breathable member, there is one described in Patent Document 1. In this surface combustion burner, the fuel gas that is ejected from the combustion header and flows from the inside to the outside of the breathable member, and the combustion air that passes through the outside of the combustion header and flows from the inside to the outside of the breathable member. , The surface of the breathable member is mixed and burned to form a flame in the cylindrical barrier. With this, it is possible to prevent local overheating of the combustion header and flashback to the inside of the combustion header, and to form a stable flame along the axial direction of the barrier.

Japanese Patent No. 5475374

However, in the conventional surface combustion burner, no special device has been made in the shape of the combustion header. Therefore, when the combustion is performed on the surface of the breathable member provided on the outer side surface of the combustion header, the combustion header and the breathable member move toward the downstream side of the flow of the combustion air and the combustion gas. It is heated violently. In particular, when the distance between the breathable member and the barrier becomes narrow, the durability of the breathable member may deteriorate. Further, the fuel gas and the combustion air may not be sufficiently mixed on the surface of the breathable member, and the concentration of the fuel gas in this mixture may be biased, resulting in unstable flame formation.

The present invention has been made in view of the above problems, and has been obtained in order to provide a surface combustion burner capable of improving the durability of a breathable member and making it possible to prevent uneven concentration of fuel gas. ..

One aspect of the present invention is an air tube through which combustion air passes,
Disposed within the air pipe, a fuel pipe fuel gas passes,
Are arranged in the air tube is connected to the distal end side of the fuel tube, the combustion header for jetting air Ki及 beauty the fuel gas for the combustion,
A breathable member made of metal knit formed of a metal fiber material, which is provided on the outer surface of the combustion header,
In the combustion header, the tip side portion where the breathable member is provided, convex portions and concave portions are alternately formed at a plurality of places around the central axis of the combustion header,
On the outer peripheral surface of the convex portion, a tapered outer peripheral surface is formed whose outer shape is reduced toward the tip side of the combustion header,
The breathable member is provided along the tapered outer peripheral surface,
In the above combustion header,
A gas passage formed along the central axis of the combustion header,
A plurality of gas outlets communicating the gas passage with the tapered outer peripheral surface of the protrusion at a plurality of locations around the central axis of the combustion header;
A plurality of first air jets communicating the base end surface of the combustion header and the recess at a plurality of locations around the central axis of the combustion header;
In a state where a gap is formed between the inner peripheral surface of the air pipe and a flange portion protruding toward the outer peripheral side at the base end portion of the combustion header,
The surface combustion burner has a plurality of second air jets penetrating the flange portion formed at a plurality of locations around the central axis of the flange portion .

In the surface combustion burner, the breathable member is provided along the tapered outer peripheral surface whose outer shape is reduced toward the tip side of the combustion header. As a result, the distance between the air tube and the breathable member becomes wider toward the tip side of the combustion header. Therefore, on the outside of the breathable member, it is possible to secure a space that becomes wider toward the downstream side of the flow of the combustion air and the combustion gas. Then, the combustion of the combustion gas with the fuel gas or the air-fuel mixture on the surface of the breathable member is performed using this space, and the breathable member is provided at the tip side of the combustion header (or the combustion air and the combustion gas). It is possible to avoid the intense heating as it goes to the downstream side of the flow). As a result, the durability of the breathable member can be improved.

Further, in the above surface combustion burner, the combustion header has a plurality of second air jets in addition to the plurality of gas jets and the plurality of first air jets. Then, the fuel gas or the air-fuel mixture ejected from the plurality of gas ejection ports passes from the inside to the outside of the breathable member. Further, the combustion air ejected from the plurality of first air ejection ports passes from the inside to the outside of the breathable member, and the combustion air ejected from the plurality of second air ejection ports is the tip of the combustion header. Pass to the side. When the fuel gas or the air-fuel mixture ejected from the plurality of gas ejection ports and the combustion air ejected from the plurality of first air ejection ports are mixed on the surface (outer side) of the breathable member, Combustion air ejected from the plurality of second air ejection ports is also mixed with the mixed gas. As a result, the fuel gas and the combustion air are sufficiently mixed on the surface (outer side) of the breathable member, the concentration of the fuel gas in this mixture is less likely to be biased, and a stable flame is formed. be able to.

Therefore, according to the surface combustion burner, it is possible to improve the durability of the breathable member and make it possible to prevent uneven concentration of the fuel gas.

FIG. 4 is a view showing the surface combustion burner according to the first embodiment and is a cross-sectional view taken along the line I-I in FIG. 3. FIG. 4 is a view showing the surface combustion burner according to the first embodiment and is a cross-sectional view taken along the line II-II in FIG. 3. 1 is a view showing a surface combustion burner according to the first embodiment, and is a view taken along the arrow III in FIG. Sectional drawing which shows the surface combustion burner concerning Embodiment 2. Sectional drawing which shows the surface combustion burner concerning Embodiment 3. FIG. Sectional drawing which shows other surface combustion burner concerning Embodiment 3.

A preferred embodiment of the surface combustion burner described above will be described with reference to the drawings.
(Embodiment 1)
As shown in FIGS. 1 to 3, the surface combustion burner 1 of the present embodiment includes an air pipe 3 through which the combustion air A passes, a fuel pipe 4 disposed in the air pipe 3, and through which a fuel gas F passes. The combustion header 2 is connected to the front end side L1 of the fuel pipe 4 and is arranged in the air pipe 3, and is provided on the outer surface of the combustion header 2 for ejecting the combustion air A and the fuel gas F. And a breathable member 26 made of a fiber material. On the outer peripheral surface of the combustion header 2 where the breathable member 26 is provided, a tapered outer peripheral surface 201 is formed, the outer shape of which decreases as it goes to the front end side L1 of the combustion header 2. The breathable member 26 is provided along the tapered outer peripheral surface 201. In FIG. 3, the breathable member 26 and the like are omitted.

The combustion header 2 has a gas passage 21, a plurality of gas ejection ports 221, a plurality of first air ejection ports 23, a flange portion 24, and a plurality of second air ejection ports 241. The gas passage 21 is formed along the central axis of the combustion header 2 as shown in FIG. The plurality of gas ejection ports 221 are formed at a plurality of locations around the central axis of the combustion header 2 so that the gas passage 21 and the tapered outer peripheral surface 201 communicate with each other. As shown in FIG. 2, the plurality of first air outlets 23 connect the base end surface 202 of the combustion header 2 and the tapered outer peripheral surface 201 at a plurality of locations around the central axis of the combustion header 2. Has been formed. As shown in FIG. 1, the flange portion 24 is formed so as to project to the outer peripheral side at the base end portion of the combustion header 2. The plurality of second air ejection ports 241 are formed so as to penetrate the flange portion 24.

The surface-combustion burner 1 of this embodiment is arranged in a heating furnace or the like and is used to heat the atmospheric gas in the furnace.
As shown in FIGS. 1 and 2, the air pipe 3 and the fuel pipe 4 are arranged in parallel with each other and have a double pipe structure. The tip of the air pipe 3 is located further on the tip side L1 than the tip of the combustion header 2. The entire outer circumference of the combustion header 2 is covered with the air pipe 3. In the state where the combustion header 2 is arranged inside the air pipe 3, a slight gap M is formed between the flange portion 24 of the combustion header 2 and the air pipe 3.

The central axis of the combustion header 2 is parallel to the central axes of the air pipe 3 and the fuel pipe 4. The gas passage 21 of the combustion header 2 is formed in the central portion including the central axis of the combustion header 2. The tip of the gas passage 21 is closed by a closing member 27 provided on the combustion header 2. The combustion header 2 of this embodiment includes a first header part 2A in which a gas passage 21, a plurality of gas outlets 221 and a plurality of first air outlets 23 are formed, a flange portion 24 and a plurality of second air outlets. It is configured by combining with the second header part 2B in which 241 is formed. The second header component 2B is attached to the outer periphery of the base end portion of the first header component 2A, and is fixed to the first header component 2A by welding or the like.

As shown in FIG. 3, on the outer peripheral surface of the first header component 2A, a plurality of concave portions 230 that form the first air ejection port 231 and a convex portion 22 are formed in the circumferential direction C around the central axis thereof. Are formed alternately. Each recess 230 is recessed from the outer peripheral surface of the first header component 2A, is formed along the central axis, and is formed in a state parallel to the central axis. As shown in FIG. 1 and FIG. 3, the plurality of gas ejection ports 221 are formed in the radial direction of the first header part 2A from the gas passage 21 at the formation positions of the plurality of protrusions 22 in the circumferential direction C of the first header part 2A. It is formed toward R. Then, the gas ejection ports 221 and the first air ejection ports 23 are formed alternately at a plurality of positions in the circumferential direction C of the combustion header 2.

As shown in FIGS. 1 to 3, the second header component 2B has an annular shape, and has a mounting portion 25 mounted on the outer periphery of the first header component 2A and a radial direction R from the mounting portion 25. And a flange portion 24 protruding outward. A part of each first air ejection port 231 is formed as a through hole surrounded by the recess 230 and the mounting portion 25. The plurality of second air ejection ports 241 are formed side by side at equal intervals in the circumferential direction C of the flange portion 24. Further, the flange portion 24 is also formed with an insertion port 242 for inserting the spark rod 281 for ignition. The tip portion of the spark rod 281 is arranged so as to face an ignition earth rod 282 provided on the outer peripheral surface of the first header part 2A.

The mounting portion 25 of the second header component 2B is mounted on the outer periphery of the base end side portion of the first header component 2A, and the tapered outer peripheral surface 201 of the first header component 2A is formed on the distal end side portion of the first header component 2A. Has been done.
The breathable member 26 of this embodiment is a metal knit made of heat-resistant metal fiber as a fiber material. The breathable member 26 can be made of metal or ceramics having a plurality of pores or voids that allow gas to pass, in addition to the metal knit. The breathable member 26 can also be made of, for example, glass wool formed of glass fibers. The breathable member 26 can be made of various materials that have heat resistance, breathability, and are nonflammable. The breathable member 26 is fixed to the first header component 2A and the second header component 2B by welding or the like.

In the surface-combustion burner 1, the combustion header 2 guides the fuel gas F and the combustion air A through different paths until just before the air-permeable member 26, and the fuel gas F and the combustion air A are communicated with each other. Is mixed and burned on the surface of the.
When performing combustion in the surface combustion burner 1, the fuel gas F passes through the fuel pipe 4 and the gas passage 21 of the combustion header 2, and is branched from the gas passage 21 into a plurality of gas ejection ports 221. The gas flows and is ejected from the opening tip of each gas ejection port 221 in the tapered outer peripheral surface 201, and passes from the inside to the outside of the breathable member 26.

On the other hand, the combustion air A passes through the air pipe 3 to form a plurality of first air outlets 23 in the combustion header 2 and a plurality of second air outlets 241 of the flange portion 24 of the combustion header 2. It branches and flows. Then, the combustion air A is ejected from the opening tips of the plurality of first air ejection ports 23 on the tapered outer peripheral surface 201, passes from the inside to the outside of the breathable member 26, and collides with the flange portion 24. , And is ejected from the plurality of second air ejection ports 241 and passes to the front end side L1 of the combustion header 2.

Then, the fuel gas F ejected from the plurality of gas ejection ports 221 and the combustion air A ejected from the plurality of first air ejection ports 23 are in the circumferential direction C on the surface (outside) of the air-permeable member 26. Move to and mix with each other. Further, on the surface (outer side) of the breathable member 26, the fuel gas F ejected from the plurality of gas ejection ports 221 and the combustion air A ejected from the plurality of first air ejection ports 23 have a plurality of The combustion air A ejected from the second air ejection port 241 is mixed. As a result, the fuel gas F and the combustion air A are sufficiently mixed on the surface (outer side) of the air-permeable member 26, and the concentration of the fuel gas F in this mixture can be prevented from becoming uneven. Then, the mixed gas of the fuel gas F and the combustion air A is ignited by the spark generated between the spark rod 281 and the earth rod 282, burns on the surface of the breathable member 26, and the flame in the air tube 3 is generated. Form H. At this time, since the concentration of the fuel gas F in the air-fuel mixture is less likely to be biased, the flame H can be stably formed.

Further, in the present embodiment, the plurality of second air ejection ports 241 are formed side by side at equal intervals in the circumferential direction C of the flange portion 24. Thereby, in each part of the combustion header 2 in the circumferential direction C, the fuel gas F ejected from the plurality of gas ejection ports 221 and the combustion air A ejected from the plurality of first air ejection ports 23 are provided. The combustion air A ejected from the plurality of second air ejection ports 241 is mixed more uniformly. Then, the bias of the air ratio (excess air ratio) in each portion of the combustion header 2 in the circumferential direction C can be reduced, and the flame H can be formed more stably.

Further, since the plurality of gas ejection ports 221 and the plurality of first air ejection ports 23 formed by the recesses 230 are located at different positions in the circumferential direction C in the combustion header 2, the fuel gas F and the fuel gas F are formed on the surface of the breathable member 26. The combustion air A is not rapidly mixed, but is gently mixed. Thereby, the slow combustion is performed in substantially the entire region of the breathable member 26, and the temperature of the flame H formed is kept low.

Further, the breathable member 26 is provided along the tapered outer peripheral surface 201 whose outer shape is reduced toward the tip side L1 of the combustion header 2. As a result, as shown in FIGS. 1 and 2, the distance between the air tube 3 and the air-permeable member 26 in the radial direction R becomes wider toward the tip end side L1 of the combustion header 2. Therefore, on the outside of the breathable member 26, it is possible to secure a space S that becomes wider as it goes to the downstream side of the flow of the combustion air A and the combustion gas. Then, the combustion of the fuel gas F and the combustion air A on the surface of the air permeable member 26 is performed using this space S, and the air permeable member 26 causes the air permeable member 26 to move toward the tip end side L1 (or for combustion) of the combustion header 2. Vigorous heating can be avoided as it goes to the downstream side of the flow of air A and the combustion gas. In other words, it is possible to prevent the heat generated by combustion from overlapping in the radial direction of the combustion header 2 and to easily escape toward the tip side L1 of the combustion header 2. As a result, the durability of the breathable member 26 can be improved.

Therefore, according to the surface combustion burner 1 of the present embodiment, it is possible to improve the durability of the breathable member 26 and prevent the concentration of the fuel gas F from becoming uneven.

(Embodiment 2)
The present embodiment shows one variation of the surface combustion burner 1 that recovers exhaust heat.
The surface combustion burner 1 of the present embodiment constitutes a direct-fire (direct heating) self-exhaust heat recovery burner. Specifically, as shown in FIG. 4, an exhaust pipe 5 for collecting the exhaust gas G after combustion is provided on the outer peripheral side of the air pipe 3 of the surface combustion burner 1. The exhaust pipe 5 is provided with an exhaust port 51 through which the exhaust gas G is exhausted. Further, the air pipe 3 is provided with an air supply port 31 into which the combustion air A is introduced.

The surface combustion burner 1 of this embodiment can be used for a heating furnace or the like that directly heats an object to be heated by the flame H. Then, the combustion in the combustion header 2 is performed, a flame H is formed toward the tip side L1 of the tubular air tube 3, and the flame H heats the inside of the furnace such as a heating furnace, The exhaust gas G is recovered from the exhaust pipe 5. At this time, heat exchange between the exhaust gas G passing through the exhaust pipe 5 and the combustion air A passing through the air pipe 3 is performed, and exhaust heat of the exhaust gas G is recovered to the combustion air A.
In this embodiment, by recovering the exhaust heat of the exhaust gas G, it is possible to perform highly efficient combustion with suppressed exhaust loss. Also in this embodiment, the other configurations and the components indicated by the reference numerals in the drawing are the same as those in the first embodiment, and the same effects as the first embodiment can be obtained.

(Embodiment 3)
This embodiment also shows another variation of the surface combustion burner 1 that recovers exhaust heat.
The surface combustion burner 1 of this embodiment constitutes an indirect heating type self-exhaust heat recovery burner. Specifically, as shown in FIG. 5, an exhaust pipe 5 for collecting exhaust gas G after combustion and a tip side L1 of the exhaust pipe 5 are connected to the outer peripheral side of the air pipe 3 of the surface combustion burner 1. A cylindrical radiant tube 6 having a closed end is provided. The radiant tube 6 can be made of ceramics, casting, or the like having excellent heat transfer and heat resistance.

The surface combustion burner 1 of the present embodiment can be used in a heating furnace for indirectly heating an object to be heated by a flame H, a melting and holding furnace for molten metal, an atmosphere heat treatment furnace, and the like. When the surface combustion burner 1 is used in a melting and holding furnace for molten metal, it can be used by immersing it in the molten metal. Then, when combustion is performed in the combustion header 2 to form the flame H, the inside of the furnace is indirectly heated by the radiant heat of the flame H via the radiant tube 6, and the exhaust gas G after combustion is exhausted from the exhaust pipe 5 Exhausted from. At this time, heat exchange between the exhaust gas G passing through the exhaust pipe 5 and the combustion air A passing through the air pipe 3 is performed, and exhaust heat of the exhaust gas G is recovered.

In the surface combustion burner 1 of the present embodiment, as shown in FIG. 5, the flame H formed by the combustion header 2 is formed inside the air pipe 3 toward the tip side L1 of the air pipe 3. On the other hand, in the surface combustion burner 1, as shown in FIG. 6, the tapered outer peripheral surface 201 of the combustion header 2 can be located closer to the tip side L1 than the air tube 3. In this case, the flame H formed by the combustion header 2 is formed in the radiant tube 6 toward the base end side L2.
Also in this embodiment, by recovering the exhaust heat of the exhaust gas G, it is possible to perform highly efficient combustion with suppressed exhaust loss. Also in this embodiment, the other configurations and the components indicated by the reference numerals in the drawings are the same as those in the first and second embodiments, and the same operational effects as those in the first and second embodiments can be obtained.

It should be noted that the present invention is not limited to each of the embodiments, and can be applied to further different embodiments without departing from the scope of the invention. For example, in the fuel pipe 4, instead of the fuel gas F, a mixture of the fuel gas F and the combustion air A passes, and from the plurality of gas ejection ports 221 of the combustion header 2, the fuel gas F is replaced. Alternatively, the air-fuel mixture may be jetted.

DESCRIPTION OF SYMBOLS 1 Surface-combustion burner 2 Combustion header 201 Tapered outer peripheral surface 21 Gas passage 22 Convex part 221 Gas ejection port 23 First air ejection port 230 Recessed part 24 Flange part 241 Second air ejection port 26 Air permeable member 3 Air pipe 4 Fuel pipe F Fuel gas A Combustion air

Claims (1)

An air tube through which combustion air passes,
Disposed within the air pipe, a fuel pipe fuel gas passes,
Are arranged in the air tube is connected to the distal end side of the fuel tube, the combustion header for jetting air Ki及 beauty the fuel gas for the combustion,
A breathable member made of metal knit formed of a metal fiber material, which is provided on the outer surface of the combustion header,
In the combustion header, the tip side portion where the breathable member is provided, convex portions and concave portions are alternately formed at a plurality of places around the central axis of the combustion header,
On the outer peripheral surface of the convex portion, a tapered outer peripheral surface is formed whose outer shape is reduced toward the tip side of the combustion header,
The breathable member is provided along the tapered outer peripheral surface,
In the above combustion header,
A gas passage formed along the central axis of the combustion header,
A plurality of gas outlets communicating the gas passage with the tapered outer peripheral surface of the protrusion at a plurality of locations around the central axis of the combustion header;
A plurality of first air jets communicating the base end surface of the combustion header and the recess at a plurality of locations around the central axis of the combustion header;
In a state where a gap is formed between the inner peripheral surface of the air pipe and a flange portion protruding toward the outer peripheral side at the base end portion of the combustion header,
A surface combustion burner in which a plurality of second air jets penetrating the flange portion are formed at a plurality of locations around the central axis of the flange portion .

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