JP2018112332A - Two-kind fuel burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-kind fuel burner capable of largely changing the rate of liquid fuel and gas fuel and, moreover, can combust preferably the liquid fuel while keeping flame of the liquid fuel into a combustion flame of the gas fuel when combusting the liquid fuel and the gas fuel in the mixed combustion state.SOLUTION: A liquid fuel ejection part D which atomizes a liquid fuel with atomizing air and injects atomized liquid fuel to a combustion space N is provided on a burner center part, a tubular combusting air supply path Ls which supplies combusting air to the combustion space N through an air injection hole 13 is provided on a burner outer circumferential part, a gas fuel injection nozzle 14 which injects the gas fuel to be supplied through a gas fuel supply path Lg to a gas fuel injection path 12 is provided on a portion corresponding to a part between the liquid fuel injection part D and the combusting air supply path Ls and a communication part E for introducing a part of air which flows through the combusting air supply path Ls into a negative pressure space between the gas fuel injection path 12 and the gas fuel injection nozzle 14 is formed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a two-type fuel burner that burns gaseous fuel and atomized liquid fuel in a combustion space.

Such a two-type fuel burner burns a gas fuel such as city gas and a liquid fuel such as heavy oil in a combustion space, and is used in various heating furnaces.
By atomizing the liquid fuel, combustibility is ensured. As a method for atomizing the liquid fuel, there is a method in which the liquid fuel is pressurized and sprayed in a mist form from the liquid fuel ejection nozzle. In this case, there is a disadvantage that a pump for pressurizing the liquid fuel to a high pressure is required.
Further, there is a method of atomizing using vapor pressure, but in this method, it is impossible to carry out when there is no vapor for atomization.

For this reason, as a system for atomizing liquid fuel, there is one configured to atomize liquid fuel by using gaseous fuel as atomizing gas (see, for example, Patent Document 1).
Incidentally, in Patent Document 1, a gas fuel ejection path and a mixing chamber on the tip side thereof are formed in a jet body that ejects gaseous fuel toward a combustion space, and liquid fuel is supplied from the outer peripheral side of the mixing chamber to the inside of the mixing chamber. The gas fuel and the atomized liquid fuel are ejected from the ejection body into the combustion space.

JP 2006-137965 A

  Since the conventional two-type fuel burner uses a gaseous fuel as a gas for atomizing the liquid fuel, in order to burn the liquid fuel while properly atomizing, the ratio of the liquid fuel to the gaseous fuel is increased. It was something that could not be changed.

  That is, in the type 2 fuel burner, depending on the usage situation, it may be desired to burn the liquid fuel more than the gaseous fuel or to burn the gaseous fuel more than the liquid fuel. Depending on the situation, it may be desired to burn only liquid fuel or to burn only gaseous fuel.

  However, since the conventional two-type fuel burner uses a gaseous fuel as the gas for atomizing the liquid fuel, in order to burn the liquid fuel while properly atomizing the liquid fuel, the amount of the liquid fuel is larger than that of the gaseous fuel. Therefore, it is impossible to burn the liquid fuel alone or to burn only the liquid fuel, and improvement is desired.

  The present invention has been made in view of the above circumstances, and can greatly change the ratio of liquid fuel to gaseous fuel, and when burning liquid fuel and gaseous fuel in a co-firing state, The second object is to provide a two-type fuel burner capable of burning liquid fuel satisfactorily while holding the flame properly with a combustion flame of gaseous fuel.

The two-type fuel burner of the present invention burns gaseous fuel and atomized liquid fuel in a combustion space.
In the center of the burner, the liquid fuel supplied through the liquid fuel supply passage is atomized by the atomizing air supplied through the atomization air supply passage, and the atomized liquid fuel is jetted into the combustion space. A liquid fuel ejection section is provided,
A cylindrical combustion air supply path for supplying combustion air to the combustion space through an annular air ejection hole at the tip is provided on the outer periphery of the burner,
The gas fuel is supplied to the portion corresponding to the portion between the liquid fuel injection portion and the combustion air supply passage through the gas fuel injection passage on the tip side of the burner for injecting the gaseous fuel into the combustion space, and the gas fuel supply passage. A gaseous fuel ejection nozzle for ejecting gaseous fuel into the gaseous fuel ejection path;
A communication portion for introducing a part of the air flowing through the combustion air supply path into the negative pressure space between the gaseous fuel ejection path and the gaseous fuel ejection nozzle is formed.

That is, the liquid fuel supplied through the liquid fuel supply path is atomized by the atomizing air supplied through the atomizing air supply path, and is ejected from the liquid fuel ejection section in the center of the burner to the combustion space. .
In this case, if the concentration of the atomized liquid fuel with respect to the atomizing air is too low, the flammability of the liquid fuel decreases due to a decrease in the ignitability of the liquid fuel. The supply amount is set to an amount smaller than the amount of air required to burn the liquid fuel, for example, about 20% of the amount of air required to burn the liquid fuel, thereby ensuring the combustibility of the liquid fuel. However, the liquid fuel will be atomized.

  Since the combustion air supplied through the combustion air supply passage is ejected from the annular air ejection hole on the outer periphery of the burner to the combustion space, the combustion air ejected from the air ejection hole is used as the combustion air for the liquid fuel. Used, the atomized liquid fuel ejected from the liquid fuel ejection portion into the combustion space is combusted.

  The gaseous fuel is ejected from the gaseous fuel ejection path provided between the liquid fuel ejection section and the combustion supply path into the combustion space. The gaseous fuel supplied through the gaseous fuel supply path is used as the gaseous fuel ejection path. And a communicating portion for introducing a part of the air flowing through the combustion air supply path into the negative pressure space between the gaseous fuel ejection path and the gaseous fuel ejection nozzle. Since it is provided, combustion air is premixed with the gaseous fuel ejected from the gaseous fuel ejection path into the combustion space, and the combustibility of the gaseous fuel is improved.

In other words, by ejecting gaseous fuel from the gaseous fuel ejection nozzle to the gaseous fuel ejection path, the space between the gaseous fuel ejection path and the gaseous fuel ejection nozzle becomes negative due to the venturi effect. A part of the air flowing through the combustion air supply passage in the form of being sucked flows through the communication portion to the gaseous fuel ejection passage.
As a result, the combustion fuel is premixed with the gaseous fuel ejected from the gaseous fuel ejection path.

Combustion air is premixed in the gaseous fuel ejected from the gaseous fuel ejection path into the combustion space, but the combustion air required for combustion is insufficient, so combustion from the air ejection holes on the outer periphery of the burner The combustion air ejected into the space is used as combustion air for the gaseous fuel, and the gaseous fuel ejected from the gaseous fuel ejection path into the combustion space is combusted.
That is, the combustion air ejected from the air ejection hole in the outer peripheral portion of the burner to the combustion space is ejected from the liquid fuel ejection portion to the combustion space and the combustion space from the gaseous fuel ejection path. It will be used as combustion air with gaseous fuel.

  The gaseous fuel ejected from the gaseous fuel ejection path into the combustion space burns in a form covering the periphery of the atomized liquid fuel ejected from the liquid fuel ejection section into the combustion space. The atomized liquid fuel ejected from the section into the combustion space is burned while being held by the combustion flame of the gaseous fuel.

  In other words, when liquid fuel and gaseous fuel are burned, combustion is performed from the liquid fuel injection part while properly holding the flame with a combustion flame of gaseous fuel that burns with good stability by premixing the combustion air. In a state where the atomized liquid fuel ejected into the space is burned, the liquid fuel and the gaseous fuel are co-fired.

Further, since the liquid fuel is atomized with atomizing air, the liquid fuel can be appropriately atomized and burned even if the supply amount of the gaseous fuel is reduced. It is also possible to reduce the amount of fuel supplied, or in some cases, eliminate the supply of gaseous fuel and burn only liquid fuel.
Incidentally, when reducing the supply amount of gaseous fuel, it is unnecessary to reduce the supply amount of combustion air supplied through the combustion air supply passage on the outer periphery of the burner in accordance with the decrease in the supply amount of gaseous fuel. It is avoided that a large amount of combustion air is supplied.

Combustion air for the gaseous fuel that is ejected from the gaseous fuel ejection path into the combustion space is ejected from the air ejection holes on the outer periphery of the burner to the combustion space. It is also possible to burn only gaseous fuel without supplying liquid fuel.
By the way, when reducing the supply amount of liquid fuel, the supply amount of atomization air supplied through the atomization air supply passage and the supply amount of combustion air supplied through the combustion air supply passage in the outer periphery of the burner, By reducing the supply amount of liquid fuel in accordance with the decrease in supply amount, it is possible to avoid supplying an unnecessarily large amount of atomizing air and supplying an unnecessarily large amount of combustion air.
Since the combustion air is premixed with the gaseous fuel, the amount of combustion air supplied through the combustion air supply passage at the outer periphery of the burner is reduced as the combustion air for the gaseous fuel. In other words, gaseous fuel can be burned at a low air ratio.

  As described above, by atomizing the liquid fuel with the atomizing air, the liquid fuel is appropriately atomized and burned well, but the supply amount of the gaseous fuel and the supply of the liquid fuel The amount can be changed greatly. In other words, the ratio of liquid fuel to gaseous fuel can be changed greatly.

  In short, according to the characteristic configuration of the two-type fuel burner of the present invention, the ratio between the liquid fuel and the gaseous fuel can be greatly changed, and when the liquid fuel and the gaseous fuel are burned in a co-firing state, The fuel can be burned satisfactorily while properly holding the flame with a combustion flame of gaseous fuel.

A further characteristic configuration of the two-type fuel burner of the present invention is that a plurality of the gaseous fuel ejection paths are provided at intervals in the circumferential direction on an annular body surrounding the liquid fuel ejection section,
The gaseous fuel ejection nozzle is provided corresponding to each of the plurality of gaseous fuel ejection paths.

That is, since the gaseous fuel ejection path is formed in the annular body that surrounds the liquid fuel ejection section with a different phase in the circumferential direction, the annular body covers the outer periphery of the liquid fuel ejection section. If installed, a plurality of gaseous fuel ejection paths can be provided with different phases in the circumferential direction.
That is, the installation configuration of the plurality of gaseous fuel ejection paths can be simplified.

  Then, by providing a plurality of gaseous fuel ejection nozzles corresponding to each of the plurality of gaseous fuel ejection paths, the mist ejected from the liquid fuel ejection section into the combustion space when burning the liquid fuel and the gaseous fuel The nebulized liquid fuel sprayed into the combustion space is burned well while the surrounding area of the liquid fuel is properly covered with the combustion flame of the gaseous fuel and the flame is held with the combustion flame of the gaseous fuel. Can be made.

  In short, according to the further characteristic configuration of the two-type fuel burner of the present invention, the atomized liquid fuel injected into the combustion space is gasified while simplifying the installation configuration of the plurality of gaseous fuel injection paths. It is possible to hold the fuel properly with the fuel combustion flame and burn it well.

  A further characteristic configuration of the two-type fuel burner of the present invention is that the gaseous fuel ejection passage and the front end portion of the combustion air supply passage are formed in an inclined shape positioned radially inward as the burner front end side. There is in point.

  That is, since the tip side portions of the gaseous fuel ejection passage and the combustion air supply passage are formed in an inclined shape located on the radially inner side toward the burner tip side, the diameter of the burner tip portion can be reduced. Therefore, for example, when installing the type 2 fuel burner on the furnace wall of the heating furnace, it is possible to reduce the diameter of the hole for installing the burner that opens in the furnace wall. Can be made.

  Further, since the gaseous fuel ejected from the gaseous fuel ejection passage and the combustion air ejected from the air ejection hole are directed toward the burner center side, the combustion of the gaseous fuel is performed when the liquid fuel and the gaseous fuel are burned. By burning the flame while suppressing the outward spread, the atomized liquid fuel ejected from the liquid fuel ejection section into the combustion space is more appropriately held by the combustion flame of the gaseous fuel. It can be burned well.

  In short, according to the further characteristic configuration of the two-type fuel burner of the present invention, the convenience of installation can be improved, and the atomized liquid fuel injected into the combustion space can be used as a combustion flame of gaseous fuel. Therefore, it can be burned well while properly holding the flame.

According to a further characteristic configuration of the two-type fuel burner of the present invention, the liquid fuel supply path is disposed inside the atomizing air supply path,
The liquid fuel ejection part is configured to atomize the liquid fuel ejected from the tip of the liquid fuel supply path with the atomizing air ejected from the periphery of the tip of the liquid fuel supply path. There is in point.

  That is, by atomizing the atomizing air from the periphery of the front end of the liquid fuel supply path to atomize the liquid fuel ejected from the front end of the liquid fuel supply path, the liquid fuel supply path is used for atomization. The liquid fuel can be atomized with a simple configuration arranged inside the air supply path.

  In short, according to the further characteristic configuration of the two-type fuel burner of the present invention, the configuration for atomizing the liquid fuel can be simplified.

  A further characteristic configuration of the two-type fuel burner of the present invention includes: a liquid fuel adjustment unit that adjusts the supply amount of the liquid fuel; an atomization air adjustment unit that adjusts the supply amount of the atomization air; There is a gas fuel adjustment unit for adjusting the supply amount and a combustion air adjustment unit for adjusting the supply amount of the combustion air.

  That is, since the supply amount of liquid fuel, the supply amount of atomizing air, the supply amount of gaseous fuel, and the supply amount of combustion air can be adjusted, the ratio of the liquid fuel and the gaseous fuel is greatly changed. Thus, the liquid fuel and the gaseous fuel can be co-fired, and switching to a state where only the liquid fuel is combusted or a state where only the gaseous fuel is combusted can be performed appropriately.

  In short, according to the further characteristic configuration of the two-type fuel burner of the present invention, the combustion state can be appropriately changed.

  A further characteristic configuration of the two-type fuel burner of the present invention is that the combustion space is formed in a truncated cone shape whose diameter is increased toward the tip side.

  In other words, in the combustion space formed in a truncated cone shape whose diameter increases toward the tip side, gaseous fuel and liquid fuel can be combusted in a mixed combustion state while suppressing radial expansion. Liquid fuel can be burned well in a mixed combustion state.

  In short, according to the further characteristic configuration of the two-type fuel burner of the present invention, the gaseous fuel and the liquid fuel can be favorably burned in the mixed combustion state.

Longitudinal side view of two types of fuel burner Vertical side view of burner tip Front view of burner tip Longitudinal side view of the tip of the second type fuel burner of another embodiment

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Overall structure of type 2 fuel burner)
As shown in FIG. 1, a frustoconical combustion space N whose diameter increases toward the tip side is formed in the burner tile 1 attached to the furnace wall R of the heating furnace, and a flame F is formed inside the combustion space N. A two-type fuel burner B that burns in this manner is provided.

The two-type fuel burner B is configured to burn using liquid fuel such as heavy oil and gaseous fuel such as city gas as fuel.
That is, the gas fuel and the atomized liquid fuel are configured to burn in the combustion space N.

That is, an outer cylinder 3 is provided in a state of being connected to an annular support 2 mounted on an end surface portion of the burner tile 1, and an annular coupling body 4 is provided at an end of the outer cylinder 3. A first intermediate cylinder 5 is provided while being supported by the body 4.
In a state in which the second intermediate cylinder 6 having a smaller diameter than the first intermediate cylinder 5 and the inner cylinder 7 fitted into the second intermediate cylinder 6 are connected and supported by the support body 8 at the end of the first intermediate cylinder 5. Is provided.
Inside the inner cylinder 7, a liquid fuel supply pipe 9 that supplies liquid fuel is provided in a state of being supported by a connection body 10 connected to an end of the inner cylinder 7.

  As shown in FIG. 2, an air guide body 7A having a smaller diameter toward the distal end side is provided at the distal end portion of the inner cylinder 7, and a liquid fuel ejection body 9A is disposed at the distal end portion of the liquid fuel supply pipe 9, The outer surface of the distal end portion of the ejection body 9A is formed to have a smaller diameter toward the distal end side in a state of facing the air guide body 7A.

The outer cylinder 3, the first intermediate cylinder 5, the second intermediate cylinder 6, the inner cylinder 7, and the liquid fuel supply pipe 9 are arranged concentrically around the axis of the type 2 fuel burner B.
An annular body 11 is provided so as to cover the outer periphery of the air guide body 7A at the tip of the inner cylinder 7. The annular body 11 is provided with gaseous fuel ejection passages 12 for ejecting gaseous fuel into the combustion space N at intervals in the circumferential direction (see FIG. 3).

In the present embodiment, the annular body 11 is provided in a state of being formed integrally with the air guide body 7 </ b> A at the distal end portion of the inner cylinder 7. That is, the annular body 11 is formed in a form including the air guide body 7A on the radially inner side and the annular portion forming the gaseous fuel ejection path 12 on the radially outer side.
Instead of such a configuration, the annular body 11 and the air guide body 7A may be formed separately, and the annular body 11 may be provided so as to be externally fitted to the air guide body 7A.

An atomizing air supply path Lm for supplying atomizing air is formed between the inner cylinder 7 and the liquid fuel supply pipe 9, and the atomizing air supply path Lm is formed inside the liquid fuel supply pipe 9. A liquid fuel supply path Ln disposed inside is formed.
A swirl vane 16 for swirling the atomizing air is provided at a position corresponding to between the ejection body 9A and the air guide body 7A.
Therefore, the liquid fuel ejected from the ejection body 9A is atomized with the atomizing air ejected toward the radially inward side between the ejection body 9A and the air guide body 7A, and atomized. A liquid fuel ejection part D for ejecting the liquid fuel into the combustion space N is formed at the center of the burner.

That is, the liquid fuel ejection part D atomizes the liquid fuel ejected from the front end of the liquid fuel supply path Ln with the atomizing air ejected from the periphery of the front end of the liquid fuel supply path Ln. The annular body 11 is provided in a state surrounding the liquid fuel ejection portion D.
By the way, if the concentration of the liquid fuel with respect to the atomizing air is too low, the flammability of the liquid fuel will decrease due to a decrease in the ignitability of the liquid fuel, etc. The amount is smaller than the amount of air required to burn the fuel, and in this embodiment, the amount is about 20% of the amount of air required to burn the liquid fuel.

An annular air ejection hole 13 for ejecting combustion air into the combustion space N is formed between the support body 2 and the annular body 11, and is located on the inner side of the outer cylinder 3. A cylinder that supplies combustion air to the air ejection hole 12 at the tip at a position corresponding to the outer side of the one intermediate cylinder 5 (in other words, between the outer cylinder 3, the annular body 11, and the first intermediate cylinder 5). A combustion air supply passage Ls having a shape is formed.
That is, a cylindrical combustion air supply passage Ls for supplying combustion air to the annular air ejection hole 13 and the air ejection hole 12 is provided on the outer periphery of the burner.

And between the liquid fuel injection part D and the combustion air supply path Ls, a cylinder is formed between the gaseous fuel injection path 12 formed in the annular body 11 and the first intermediate cylinder 5 and the second intermediate cylinder 6. A gaseous fuel ejection nozzle 14 is provided for ejecting gaseous fuel supplied through the gaseous fuel supply path Lg formed in a shape into the gaseous fuel ejection path 12.
That is, the gas fuel is supplied to the portion corresponding to the space between the liquid fuel injection portion D and the combustion air supply path Ls through the gas fuel injection path 12 on the tip side of the burner that jets gaseous fuel into the combustion space N, and the gas fuel supply path Lg. A gaseous fuel ejection nozzle 14 for ejecting the gaseous fuel to be ejected into the gaseous fuel ejection path 12 is provided.

Further, a communication part E that introduces a part of the air flowing through the combustion air supply path Ls into the negative pressure space between the gaseous fuel ejection path 12 and the gaseous fuel ejection nozzle 14 is connected to the gaseous fuel ejection path 12. The space between the gaseous fuel injection nozzles 14 and the combustion air supply path Ls are formed so as to communicate with each other.
That is, the communication part E is configured in such a manner that a part on the radially inner side of the combustion air supply path Ls communicates with the space between the gaseous fuel ejection path 12 and the gaseous fuel ejection nozzle 14.

  Therefore, by ejecting the gaseous fuel from the gaseous fuel ejection nozzle 14 to the gaseous fuel ejection path 12, the space between the gaseous fuel ejection path 12 and the gaseous fuel ejection nozzle 14 becomes a negative pressure state due to the venturi effect. Part of the air flowing through the combustion air supply path Ls is introduced into the gaseous fuel ejection path 12 in the form of being sucked in the pressure space, and as a result, ejected from the gaseous fuel ejection path 12. The gaseous fuel is configured so that combustion air is premixed.

  Incidentally, the annular closing plate 15 that closes the annular opening between the tip of the first intermediate cylinder 5 and the tip of the second intermediate cylinder 6 is in a state in which the connection location of the gaseous fuel injection nozzle 14 is open, A gas fuel injection nozzle 14 is attached to the closing plate 15 at the tip of the intermediate cylinder 5 and the second intermediate cylinder 6.

  Therefore, the two-type fuel burner B uses the atomized liquid fuel ejected from the liquid fuel ejection portion D at the center of the burner to the combustion space N and the gaseous fuel ejected from the gaseous fuel ejection path 12 to the air. Combustion is performed using combustion air ejected from the ejection holes 12, and combustion is performed in the combustion space N in a mixed combustion state.

  In addition, the type 2 fuel burner B2 mixes a part of the air flowing through the combustion air supply path Ls with the gaseous fuel ejected from the gaseous fuel ejection nozzle 14 to the gaseous fuel ejection path 12, and gas By premixing air for fuel with the gaseous fuel ejected from the fuel ejection passage 12, the gaseous fuel is burned with good stability, and the liquid fuel is ejected with the combustion flame of the gaseous fuel that burns with good stability. The liquid fuel and the gaseous fuel are mixedly fired while properly atomizing the atomized liquid fuel ejected from the part D into the combustion space N.

(Regarding adjustment of combustion state)
As shown in FIG. 1, a liquid fuel adjustment valve Vn is provided in the external liquid fuel passage Zn connected to the liquid fuel supply pipe 9 as a liquid fuel adjustment unit that adjusts the supply amount of the liquid fuel.
As an atomizing air adjusting unit for adjusting the amount of atomizing air supplied to the external atomizing air passage Zm connected to the atomizing air inlet Wm of the atomizing air supply passage Lm, atomization is performed. An air adjustment valve Vm is provided.

Similarly, a gas fuel adjustment valve Vg is provided in the external gas fuel passage Zg connected to the gas fuel inlet portion Wg of the gas fuel supply passage Lg as a gas fuel adjustment portion that adjusts the supply amount of the gas fuel.
Further, a combustion air adjustment valve Vs is provided as a combustion air adjusting unit that adjusts the supply amount of combustion air to the external combustion air passage Zs connected to the combustion air inlet Ws of the combustion air supply passage Ls. Is provided.

  In the present embodiment, the external atomizing air passage Zm and the external combustion air passage Zs are provided in a form branched from a common air supply passage Zk that guides air from an air supply section such as an air supply blower. However, you may implement in the form which provides air supply parts, such as an air supply blower, with respect to each of the external atomization air path Zm and the external combustion air path Zs.

Therefore, the supply amount of liquid fuel and the supply amount of gaseous fuel can be changed according to the usage situation, etc., and the supply of combustion air can be changed according to the change in the supply amount of liquid fuel and the supply amount of gaseous fuel The amount can be changed.
Moreover, when changing the supply amount of the liquid fuel, the supply amount of the atomizing air can be changed in accordance with the supply amount of the liquid fuel.

  That is, since the type 2 fuel burner B of this embodiment is for atomizing the liquid fuel with the atomizing air, the liquid fuel is appropriately atomized even if the supply amount of the gaseous fuel is decreased. Since the fuel can be combusted, the supply amount of the gaseous fuel can be reduced. In some cases, the supply of the gaseous fuel can be eliminated and only the liquid fuel can be combusted.

  Further, since the combustion air for the gaseous fuel ejected from the gaseous fuel ejection passage 12 into the combustion space N is ejected from the air ejection holes 13 on the outer periphery of the burner to the combustion space N, the amount of liquid fuel supplied is reduced. In some cases, it is possible to eliminate the supply of liquid fuel and to burn only gaseous fuel.

  When increasing or decreasing the supply amount of gaseous fuel or the supply amount of liquid fuel, the supply amount of combustion air supplied through the combustion air supply path Ls is adjusted to increase or decrease in accordance with the supply amount of gaseous fuel or liquid fuel. become.

[Another embodiment]
Next, although another embodiment is described, this another embodiment shows another embodiment of the burner tip portion, and the other configurations are the same as the above-described embodiment. Only the different parts will be described, and description of parts having the same configuration as in the above embodiment will be omitted.

  In the said embodiment, although the case where the front end side part of the gaseous fuel ejection path 12 and the combustion air supply path Ls was formed in the form parallel to the burner axial center along a burner longitudinal direction was illustrated, in this another embodiment. As shown in FIG. 4, the tip side portions of the gaseous fuel ejection passage 12 and the combustion air supply passage Ls are formed in an inclined shape that is located radially inward as the burner tip side.

  Thus, the diameter of the tip of the burner can be reduced by forming the tip side portions of the gaseous fuel ejection passage 12 and the combustion air supply passage Ls so as to be inclined inward in the radial direction toward the tip of the burner. Therefore, it is possible to reduce the diameter of the opening formed in the furnace wall R in order to mount the type 2 fuel burner B, and to improve the installation property of the type 2 fuel burner B.

[Other alternative embodiments]
Next, other embodiments are listed.
(1) In the above embodiment, the liquid fuel ejection part D atomizes the liquid fuel ejected from the front end of the liquid fuel supply path Ln with the atomizing air ejected from the periphery of the front end of the liquid fuel supply path Ln. For example, the liquid fuel is supplied by supplying the liquid fuel into the atomizing air supply path Lm and ejecting the liquid fuel in a mixed state of the liquid fuel and the atomizing air. The specific configuration of the liquid fuel ejection part D can be changed in various ways, such as to atomize the fuel.

(2) In the above embodiment, the case where the gaseous fuel ejection path 12 is formed in the annular body 11 surrounding the liquid fuel ejection section D is illustrated, but the members forming the gaseous fuel ejection path 12 are arranged in the circumferential direction. In the form, the gaseous fuel ejection path 12 may be formed.

(3) In the above embodiment, the gaseous fuel supply passage Lg is formed in a cylindrical shape, and the gaseous fuel injection nozzle 14 is connected to the tip of the gaseous fuel supply passage Lg. However, if the circumferential phase is different, Alternatively, a plurality of gaseous fuel supply passages Lg connected to each of the gaseous fuel ejection nozzles 14 to be positioned may be provided.

(4) In the above embodiment, the case where the type 2 fuel burner B is installed in the heating furnace is illustrated, but the type 2 fuel burner B can be applied to various heating, for example, installed in a boiler.

  The configuration disclosed in the above embodiment (including another embodiment, the same shall apply hereinafter) can be applied in combination with the configuration disclosed in the other embodiment, as long as no contradiction occurs. The embodiment disclosed in this specification is an exemplification, and the embodiment of the present invention is not limited to this. The embodiment can be appropriately modified without departing from the object of the present invention.

11 annular body 12 gaseous fuel ejection path 13 air ejection hole 14 gaseous fuel ejection nozzle D liquid fuel ejection section E communicating section Lg gaseous fuel supply path Ln liquid fuel supply path Lm atomization air supply path Ls combustion air supply path N combustion Space Vg Gaseous fuel adjusting unit Vn Liquid fuel adjusting unit Vm Atomizing air adjusting unit Vs Combustion air adjusting unit

Claims (6)

A two-type fuel burner that burns gaseous fuel and atomized liquid fuel in a combustion space,
In the center of the burner, the liquid fuel supplied through the liquid fuel supply passage is atomized by the atomizing air supplied through the atomization air supply passage, and the atomized liquid fuel is jetted into the combustion space. A liquid fuel ejection section is provided,
A cylindrical combustion air supply path for supplying combustion air to the combustion space through an annular air ejection hole at the tip is provided on the outer periphery of the burner,
The gas fuel is supplied to the portion corresponding to the portion between the liquid fuel injection portion and the combustion air supply passage through the gas fuel injection passage on the tip side of the burner for injecting the gaseous fuel into the combustion space, and the gas fuel supply passage. A gaseous fuel ejection nozzle for ejecting gaseous fuel into the gaseous fuel ejection path;
A type 2 fuel burner in which a communication portion is formed for introducing a part of the air flowing through the combustion air supply path into a negative pressure space between the gaseous fuel ejection path and the gaseous fuel ejection nozzle. A plurality of the gaseous fuel ejection paths are provided in the annular body surrounding the liquid fuel ejection section at intervals in the circumferential direction,
2. The type 2 fuel burner according to claim 1, wherein the gaseous fuel ejection nozzle is provided corresponding to each of the plurality of gaseous fuel ejection paths.   3. The type 2 fuel burner according to claim 1, wherein tip portions of the gaseous fuel ejection passage and the combustion air supply passage are formed in an inclined shape located radially inward toward the burner tip side. The liquid fuel supply path is disposed inside the atomizing air supply path;
The liquid fuel ejection part is configured to atomize the liquid fuel ejected from the tip of the liquid fuel supply path with the atomizing air ejected from the periphery of the tip of the liquid fuel supply path. The two-type fuel burner according to any one of claims 1 to 3.   A liquid fuel adjustment unit that adjusts the supply amount of the liquid fuel, an atomization air adjustment unit that adjusts the supply amount of the atomizing air, a gas fuel adjustment unit that adjusts the supply amount of the gaseous fuel, and the combustion The type 2 fuel burner according to any one of claims 1 to 4, further comprising a combustion air adjusting unit that adjusts a supply amount of the operating air.   The two-type fuel burner according to any one of claims 1 to 5, wherein the combustion space is formed in a truncated cone shape whose diameter increases toward the tip side.

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