JP2022106319A - Burner - Google Patents

Abstract

To provide a burner whose pilot flame can easily be ignited.SOLUTION: The burner 1 according to one embodiment of the present invention, comprises a pilot fuel supply pipe 10 with a pilot fuel opening 11 formed on the front end thereof for flowing out the pilot fuel, a flange-shaped flame holding plate 20 attached to the outer periphery of the fuel supply pipe and disposed upstream of the pilot fuel opening 11, and a first air supply cylinder 40 at least supplying combustion air from outside of the pilot fuel supply pipe 10. The flame holding plate 20 comprises an auxiliary opening 21 to allow the combustion air to flow through an area adjacent to the pilot fuel supply pipe 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a burner.

Conventionally, it is provided with a pilot fuel supply pipe that supplies fuel for forming a pilot flame that serves as a pilot flame, and a main fuel supply pipe that supplies fuel for forming a main flame for obtaining a target amount of heat. A combustion device has been proposed. Further, a burner in which a pilot fuel supply pipe is arranged in a flow path for supplying main fuel and combustion air has also been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-204940

It is desirable that the pilot flame burns stably even when air for main combustion is introduced, but if the performance as a burner that forms the main flame is prioritized and designed, the ignitability of the pilot flame will be insufficient. May become. Therefore, it is an object of the present invention to provide a burner in which the pilot flame can be easily ignited.

The burner according to one aspect of the present invention has a pilot fuel supply pipe having a pilot fuel opening formed at the tip thereof and a flame holding flame arranged in a flange shape on the outer periphery on the upstream side of the pilot fuel opening. A plate and a first air supply cylinder for supplying at least combustion air from the outside of the pilot fuel supply pipe are provided, and the flame holding plate passes the combustion air to a region close to the pilot fuel supply pipe. Has an auxiliary opening to allow.

In the burner according to one aspect of the present invention, the area of the auxiliary opening may be 1% or more of the total area of the openings that allow the combustion air to flow out to the downstream side of the flame holding plate.

The burner according to one aspect of the present invention is arranged coaxially with the pilot fuel supply pipe on the outside of the pilot fuel supply pipe and inside the first air supply pipe, and is a main fuel supply pipe for supplying the main fuel. The main fuel supply pipe further includes a closing lid portion that closes the tip end portion of the main fuel supply pipe with a predetermined distance from the flame holding plate, and the tip end portion of the main fuel supply pipe. It may have a main fuel opening formed on the outer periphery of the side and allowing the main fuel to flow out.

The burner according to one aspect of the present invention is arranged outside the first air supply cylinder, and a part of the combustion air is introduced as secondary air into the space between the burner and the first air supply cylinder. The second air supply cylinder may further include two air supply cylinders, and the first air supply cylinder may have a secondary air opening for ejecting the secondary air inward on the downstream side of the flame holding plate.

According to the present invention, it is possible to provide a burner in which the pilot flame can be easily ignited.

It is a schematic cross-sectional view of the burner which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a burner 1 according to an embodiment of the present invention. The shape of each component of the burner 1 shown in the figure has been simplified, and the dimensions of each component have been adjusted so that they can be easily seen.

The burner 1 has a pilot fuel supply pipe 10 for supplying pilot fuel, a flame holding plate 20 arranged on the outer periphery of the pilot fuel supply pipe 10, and coaxially with the pilot fuel supply pipe 10 on the outside of the pilot fuel supply pipe 10. A main fuel supply pipe 30 that is arranged to supply the main fuel, a first air supply cylinder 40 that is arranged coaxially with the pilot fuel supply pipe 10 on the outside of the main fuel supply pipe 30 and supplies the primary air, and a first 1 The second air supply cylinder 50, which is arranged coaxially with the pilot fuel supply pipe 10 on the outside of the air supply cylinder 40 and supplies secondary air, is connected to the upstream end of the second air supply cylinder 50. The first air supply cylinder 40 and the second air supply cylinder 50 are provided with an air supply chamber 60 for distributing combustion air. The burner 1 forms a downward flame in the lower combustion space by ejecting the main fuel and the combustion air downward in the vertical direction.

The pilot fuel supply pipe 10 extends in the vertical direction. A pilot fuel opening 11 for flowing out pilot fuel is formed at the tip of the pilot fuel supply pipe 10. Specifically, the pilot fuel supply pipe 10 may be configured such that the tip is sealed and a plurality of pilot fuel openings 11 penetrating in the radial direction are formed on the side wall near the tip. The diameter of the pilot fuel supply pipe 10 and the size and number of the pilot fuel openings 11 are selected so as to appropriately supply the fuel necessary for forming the pilot flame in the combustion space downstream of the flame holding plate 20. ..

The flame holding plate 20 is arranged in a crossguard shape on the outer periphery on the upstream side of the pilot fuel opening 11 of the pilot fuel supply pipe 10. The outer diameter of the flame holding plate 20 can form a gap between the inner peripheral surface of the first air supply cylinder 40 and the inner peripheral surface of the first air supply cylinder 40 through which necessary combustion air (primary air for forming the main flame) can pass. It is preferable to make it as large as possible within the range. This makes it possible to prevent the pilot flame from being blown out by the primary air supplied from the first air supply cylinder 40.

The distance D1 between the flame holding plate 20 and the pilot fuel opening 11 is preferably sufficiently small. By making the distance D1 between the flame holding plate 20 and the pilot fuel opening 11 as small as possible, it is possible to prevent the flame from being blown out by the primary air wrapping around from the outside of the flame holding plate 20. The distance D1 between the flame holding plate 20 and the pilot fuel opening 11 can be set to zero.

The flame holding plate 20 has an auxiliary opening 21 for passing combustion air in a region close to the pilot fuel supply pipe 10. The auxiliary openings 21 are formed in a number and size that allow the amount of combustion air required for forming the pilot flame to pass through. The auxiliary opening 21 may be a round hole, but may be formed in a slit shape so that a small number of combustion air required for forming a pilot flame can be supplied.

Specifically, as the lower limit of the total area of the auxiliary openings 21, the openings (the gap between the flame holding plate 20 and the first air supply cylinder 40 and the gap between the flame holding plate 20 and the first air supply cylinder 40, which will be described later, are used to allow the combustion air to flow out to the downstream side of the flame holding plate 20. 1% of the total area of the secondary air openings 41) is preferable, and 2% is more preferable. On the other hand, as the upper limit of the total area of the auxiliary openings 21, 10% of the total area of the openings that allow the combustion air to flow out to the downstream side of the flame holding plate is preferable, and 8% is more preferable. By setting the area of the auxiliary opening 21 to be equal to or larger than the lower limit, oxygen necessary for igniting and maintaining the pilot flame can be appropriately supplied. Further, by setting the area of the auxiliary opening 21 to be equal to or larger than the lower limit, even if the fuel to the pilot fuel supply pipe 10 is stopped during the main combustion operation, the pilot fuel supply pipe 10 is cooled by the air flowing out from the auxiliary opening 21. Therefore, damage due to overheating of the pilot fuel supply pipe 10 can be effectively prevented. Further, by setting the area of the auxiliary opening 21 to be equal to or less than the upper limit, an appropriate air-fuel ratio can be realized to ensure ignition and maintenance of the pilot flame.

The distance D2 between the auxiliary opening 21 and the pilot fuel supply pipe 10 is preferably sufficiently small. By making the distance D2 between the auxiliary opening 21 and the pilot fuel supply pipe 10 as small as possible, a stable pilot flame can be formed. The distance D2 between the auxiliary opening 21 and the pilot fuel supply pipe 10 can be set to zero.

The flame holding plate 20 may further have a plurality of protrusions serving as spacers on the outer periphery for keeping the distance from the first air supply cylinder 40 constant.

The main fuel supply pipe 30 is arranged on the outside of the pilot fuel supply pipe 10 coaxially with the pilot fuel supply pipe 10. The main fuel for main combustion is introduced into the space between the main fuel supply pipe 30 and the pilot fuel supply pipe 10.

The main fuel supply pipe 30 has a closing lid portion 31 that closes the tip end portion with a predetermined distance from the flame holding plate 20, and a main fuel opening that is formed on the outer periphery of the tip end side and allows the main fuel to flow out. 32 and. That is, the main fuel supply pipe 30 supplies the main fuel to the internal space of the first air supply cylinder 40 through the space between the main fuel supply pipe 30 and the first air supply cylinder 40. The diameter of the main fuel supply pipe 30 and the size and number of the main fuel openings 32 are selected so as to supply the fuel required for the main combustion of the burner 1.

In the burner 1, since the main fuel supply pipe 30 has the closing lid portion 31, a space through which combustion air flows is formed between the tip of the main fuel supply pipe 30 and the flame holding plate 20, so that the flame holding plate is formed. The auxiliary opening 21 of 20 can be provided close to the pilot fuel supply pipe 10. As a result, the air required for forming a stable pilot flame can be supplied in the vicinity of the pilot fuel opening 11 and mixed with the fuel flowing out from the pilot fuel opening 11.

The tip end portion of the main fuel supply pipe 30 may partially project to the downstream side of the closing lid portion 31 and be connected to the flame holding plate 20. In this way, the pilot fuel supply pipe is connected by connecting the tip of the main fuel supply pipe 30 to the flame holding plate 20 while securing the flow path of the combustion air between the closing lid portion 31 and the flame holding plate 20. 10. The positional relationship between the flame holding plate 20 and the main fuel supply pipe 30 can be easily determined.

The first air supply pipe 40 is arranged coaxially with the main fuel supply pipe 30 and thus the pilot fuel supply pipe 10 on the outside of the main fuel supply pipe 30, and is retained from the outside of the pilot fuel supply pipe 10 and the main fuel supply pipe 30. At least primary air is supplied to the combustion space through the gap with the flame plate 20. The diameter of the first air supply cylinder 40 is selected so as to supply the primary air required for combustion of the burner 1.

Further, the first air supply cylinder 40 is a plurality of units that eject secondary air supplied through a space between the first air supply cylinder 40 and the second air supply cylinder 50, which will be described later, to the inner combustion space on the downstream side of the flame holding plate 20. It has a secondary air opening 41. The burner 1 has a good combustion state due to the secondary air ejected from the secondary air opening 41 in the shape of the main combustion flame formed by the combustion of the combustion air flowing out from the first air supply cylinder 40 and the mixed gas of the main fuel. Can be arranged so that That is, the secondary air ejected from the secondary air opening 41 promotes the complete combustion of the main fuel by suppressing the spread of the main combustion flame to the outside. The size and number of main fuel openings 32 are selected to stabilize the main combustion flame.

The second air supply cylinder 50 is arranged on the outside of the first air supply cylinder 40 coaxially with the first air supply cylinder 40 and thus the pilot fuel supply pipe 10 and the main fuel supply pipe 30, and is connected to the first air supply cylinder 40. A part of the combustion air is introduced as secondary air into the space between them. The downstream end of the gap between the first air supply cylinder 40 and the second air supply cylinder 50 is closed by the sealing plate portion 51.

The air supply chamber 60 communicates with the upstream side of the first air supply cylinder 40 and the second air supply cylinder 50, and a supply duct 61 to which combustion air is supplied from a blower (not shown) is connected. The air supply chamber 60 divides the combustion air supplied through the supply duct 61 into primary air and secondary air, and divides the space inside the first air supply cylinder 40 and the inside of the second air supply cylinder 50. Introduce to space.

As described above, since the burner 1 includes the flame holding plate 20 having the auxiliary opening 21 for passing the combustion air in the region close to the pilot fuel supply pipe 10, the tip side of the pilot fuel supply pipe 10 is provided from the auxiliary opening 21. Can be supplied with combustion air. As a result, the combustion air required for combustion of the pilot fuel flowing out from the pilot fuel opening 11 can be effectively supplied, so that the ignitability of the pilot flame is improved. Further, even if the burner 1 stops the supply of the pilot fuel during the combustion operation, the tip portion of the pilot fuel supply pipe 10 can be cooled by the combustion air supplied from the auxiliary opening 21, so that the pilot fuel supply can be performed. The life of the tube 10 can be extended.

Further, the burner 1 has a configuration in which a main fuel opening 32 for flowing out the main fuel is formed on the outer periphery of the main fuel supply pipe 30 arranged coaxially with the pilot fuel supply pipe 10 on the outside of the pilot fuel supply pipe 10. As a result, the main fuel can be evenly supplied to the primary air flowing inside the first air supply cylinder 40, and a mixed gas capable of appropriate combustion can be generated. Further, in the burner 1, the tip of the main fuel supply pipe 30 is provided by the main fuel supply pipe 30 having a closing lid portion 31 that closes the tip of the main fuel supply pipe 30 with a predetermined distance from the flame holding plate 20. Since it is possible to secure a flow path for combustion air flowing into the auxiliary opening 21 between the flame holding plate 20 and the flame holding plate 20, the pilot flame is ignited by forming the auxiliary opening 21 in the immediate vicinity of the pilot fuel supply pipe 10. You can definitely improve your sex.

Although the preferred embodiments of the burner of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be appropriately modified.

As an example, in the burner according to the present invention, the main fuel may be finally supplied to the inside of the first air supply pipe, and it is not always necessary to use the main fuel supply pipe arranged coaxially with the pilot fuel supply pipe. There is no. In addition, fins or the like that promote mixing of the main fuel and combustion air may be provided. In the above-described embodiment, it is assumed that a gaseous fuel is used as the fuel, but a liquid fuel may be used by providing a spray nozzle or the like.

In the burner according to the present invention, the configuration for supplying secondary air is also an arbitrary configuration. For example, the secondary air may be supplied by a blower different from the blower that supplies the primary air to the first air supply cylinder. Further, the secondary air may be supplied by using a component other than the second air supply cylinder arranged coaxially with the first air supply cylinder, and the secondary air opening formed in the first air supply cylinder. It is not an essential configuration to do through.

1 Burner 10 Pilot fuel supply pipe 11 Pilot fuel opening 20 Flame retaining plate 21 Auxiliary opening 30 Main fuel supply pipe 31 Closing lid 32 Main fuel opening 40 1st air supply cylinder 41 Secondary air opening 50 2nd air supply pipe 51 Sealed Stop plate 60 Air supply chamber 61 Supply duct

Claims (4)

A pilot fuel supply pipe with a pilot fuel opening that allows pilot fuel to flow out at the tip,
A flame-retaining plate arranged in a crossguard shape on the outer periphery on the upstream side of the pilot fuel opening,
A first air supply cylinder that supplies at least combustion air from the outside of the pilot fuel supply pipe, and
With
The flame holding plate is a burner having an auxiliary opening for passing the combustion air in a region close to the pilot fuel supply pipe. The burner according to claim 1, wherein the area of the auxiliary opening is 1% or more of the total area of the openings that allow the combustion air to flow out to the downstream side of the flame holding plate. A main fuel supply pipe, which is arranged coaxially with the pilot fuel supply pipe and supplies the main fuel, is further provided outside the pilot fuel supply pipe and inside the first air supply pipe.
The main fuel supply pipe
A closing lid portion that closes the tip of the main fuel supply pipe with a predetermined distance from the flame holding plate, and a closing lid portion.
A main fuel opening formed on the outer periphery of the tip end side of the main fuel supply pipe to allow the main fuel to flow out,
The burner according to claim 1 or 2. A second air supply cylinder, which is arranged outside the first air supply cylinder and in which a part of the combustion air is introduced as secondary air, is further provided in the space between the first air supply cylinder.
The burner according to any one of claims 1 to 3, wherein the first air supply cylinder has a secondary air opening for ejecting the secondary air inward on the downstream side of the flame holding plate.

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