JPS5813803B2 - burner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a burner, which is particularly suitable for mixed combustion of liquid fuel and gas fuel, thereby achieving complete combustion of liquid fuel and reducing nitrogen oxides (NOx) generated by combustion. The present invention relates to a low pollution burner constructed as follows.

A burner that is configured to reduce NOx by injecting water as one of the propellants when generating a flame and suppressing the rapid temperature rise of the flame is proposed in an application filed by the same applicant as the present applicant. Related Utility Application No. 1988-88634
This method has already been proposed in Publication No. 3-5827.

In the burner proposed in the future, water is injected in the form of being mixed with a liquid fuel such as heavy oil or kerosene, or a gas fuel such as propane or butane.

The present invention differs from the above-mentioned water injection method in that it injects water by mixing it with air in advance, and also mixes gas fuel, air, or water vapor in advance when injecting liquid fuel. This aims to improve the atomization and complete combustion of liquid fuel, thereby reducing the generation of soot due to incomplete combustion of liquid fuel and the generation of NOx due to the rapid temperature rise of the flame, and improving from the perspective of pollution while ensuring good combustion. The purpose is to provide a burner that is

This purpose, according to the present invention, is to introduce water into a continuous annular air flow through a small hole by opening downstream of the intersection of a water supply passage and an air supply passage that intersect with each other. A first nozzle for injecting a mixture of water and air and a first nozzle for injecting a mixture of gaseous fuel, air or steam intersecting each other in a manner that introduces the liquid fuel through small holes into an annular continuous flow of gaseous fuel, air or steam. a second nozzle that opens in an annular shape around the first nozzle downstream of the intersection of the supply passage and the liquid fuel supply passage and injects gaseous fuel, air, or a mixture of water vapor and liquid fuel; This is achieved by a burner device characterized by having a third nozzle that opens annularly around the second nozzle and injects air.

According to this configuration, the water is injected in the form of a mist mixed with air in advance and is supplied separately from the fuel, so that a flame can be generated satisfactorily without interfering with the ignitability of the fuel, and the flame After generation, the temperature rise can be appropriately suppressed.

Furthermore, in the above configuration, the liquid fuel is mixed with gas fuel, air, or water vapor in advance, and is assisted in atomization by the gas fuel, air, or water vapor, and is injected as fine particles that are well atomized. ignitability and combustibility are improved.

In the above-mentioned Utility Model Application No. 51-88634, by supplying combustion air and, in some cases, fuel in stages, combustion is carried out in stages at the time of flame generation, thereby preventing the rapid growth of the flame. NOx is reduced by suppressing the temperature rise, but in the burner of the present invention as described above, combustion air is similarly supplied in stages, and in some cases, fuel is further supplied. By performing stepwise steps, it is possible to further reduce NOx.

Therefore, in the present invention, in addition to the above-described configuration, a fourth nozzle having an annular opening around the third nozzle and injecting air; and an annular opening around the fourth nozzle. It is proposed to provide a fifth nozzle for injecting gaseous fuel, air or a mixture of gaseous fuel and air.

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

The accompanying figure is a somewhat exploded sectional view of one embodiment of a burner according to the invention.

In the figure, 1 is a tube arranged along the central axis of the burner and providing a water supply passage.

The distal end of the tube 1 is closed by a plug 2, and at the distal end adjacent to the plug several small holes 3 are bored in the circumferential wall of the tube 1.

A tube 4 is arranged around the tube 1 concentrically therewith.

The tube 4 is supplied with air through a joint 5, and the air guided to its tip through the tube 4 flows across the front of the small hole 3 of the tube 1 and at this time passes through the small hole 3. It mixes with the water that has been sucked in or pushed out, and becomes an air jet containing water droplets, which is ejected from a nozzle opening 6 at its tip.

A tube 7 is further provided around the tube 4 and concentrically therewith.

The pipe 7 supplies propane through a joint 8 connected to its base.
A gaseous fuel such as butane or air or steam is supplied.

The tip of the tube T is advantageously widened into a somewhat trumpet-like shape as shown in the figure, and several small holes 9 are drilled at its base.

Another tube 10 is provided around the tube 8 so as to include these small holes 9 and surround the tube 8.

The pipe 10 receives heavy oil through a joint 11 connected to its base.
A liquid fuel such as light oil or kerosene is supplied, and this liquid fuel flows toward the closed end of the pipe 10 through an annular passage defined between the pipes 10 and 7. From this, it flows into the pipe 7 through the small hole 9 of the pipe 7, and is mixed with the gas fuel, air, or water vapor flowing in the pipe T, and is atomized. The mixture is injected from an annular nozzle 12.

The polymers of tubes 1, 4, 7 and 8 are supported by a tubular housing 13.

Air is supplied to the housing 13 through a joint 14 connected to its rear end.

In the illustrated embodiment, a butterfly-type flow control valve 15 is provided within the joint portion 14 .

The distal end of the housing 13 is tapered in diameter as shown in the figure, and forms a nozzle 16 that opens in an annular shape around the nozzle 12.

It should be noted that in the illustrated embodiment a cylindrical guide element 17 is disposed adjacent to the nozzle 16 and carried by the tube 10, which may be preferable as required for the air flow injected from the nozzle 16. It is designed to provide a rectifying action or a swirling action.

A burner throat block 1 is installed at the tip of the housing 13.
8 is attached at its flange portion 19 so as to be slidable in the axial direction.

The burner throat block 18 has a conical throat surface 20 formed at the base of the flange portion 19, and this throat surface cooperates with a conical surface 21 formed at the tip of the housing 13 to provide a space between the burner throat block 18 and the conical throat surface 20. Conical cylindrical nozzle 2
2.

An air supply port 23 is provided in the flange portion 19, and air supplied from the port is ejected through a nozzle 22.

The degree of opening of the nozzle 22 is adjusted by moving the burner throat block 18 in the axial direction with respect to the housing 13.

The burner throat block 18 further includes its throat surface 2.
An annular nozzle 25 is formed in the middle of the nozzle 4.

This annular nozzle is formed as a gap between the root part 26 and the tip part 27 that constitute the burner throat block 18, and is formed as a gap between the root part 26 and the tip part 27 along the cylindrical surface. The opening degree of the annular nozzle 25 is adjusted by relatively displacing the two.

The annular nozzle 25 communicates with an annular chamber 29 formed in the throat block 18, to which a gas fuel supply port 30 and an air supply port 31 are connected, and a predetermined amount of fuel is supplied depending on the combustion design of the burner. gas fuel or air or both.

When such a burner is operated, as described above, water is supplied from the tube 1 and air is supplied from the tube 4, and a mist mixture of these water and air is injected from the nozzle 6.

Further, gas fuel, air, or steam is supplied from the pipe 7, liquid fuel is supplied from the pipe 10, and a mist mixture of these two is injected from the nozzle 12.

The atomized material containing the fuel component injected from the nozzle 12 is ignited while being mixed mainly with the air injected from the nozzle 16 to form a flame that spreads through the burner throat.

Air is additionally supplied to this flame through the nozzle 22, and gas fuel or air or both are additionally supplied through the nozzle 25. Thus, multi-stage combustion is performed in which combustion develops in stages, and the temperature of the flame increases rapidly. Achieve complete combustion of fuel while avoiding rise.

At the same time, a mist of air and water injected from the nozzle 6 is supplied to the center of the flame, allowing combustion to develop while suppressing the internal temperature of the flame to an appropriate level.

Thus, according to the burner of the present invention, the combustion efficiency of liquid fuel can be increased by co-firing gas fuel with liquid fuel such as heavy oil, light oil, or kerosene.

In this case, complete combustion of the liquid fuel can be achieved by assisting the combustion of the liquid fuel with the gas fuel.
It has the effect of suppressing the generation of soot.

Further, by controlling the flame temperature and developing combustion through water injection and multistage combustion, the amount of NOx generated can be reduced.

In the burner of the present invention, the fuel ratio of liquid fuel and gas fuel can be varied over a wide range, and combustion modes such as flame length and temperature distribution can also be varied depending on the purpose of use of the burner. Adjustable.

In the above explanation, only liquid fuel was supplied to the pipe 10, but water may be mixed in the liquid fuel in advance, or the pipe 10 may have a separate joint part from the joint part 11. In this case, the amount of water supplied from the pipe 1 may be reduced accordingly, or in some cases, it may be completely stopped. .

Although the present invention has been described above in detail with respect to one embodiment, it will be obvious to those skilled in the art that various modifications can be made to this embodiment within the scope of the present invention.

[Brief explanation of drawings]

The accompanying figure shows a somewhat exploded longitudinal section through an embodiment of a burner according to the invention. 1: Pipe, 2: Plug, 3: Small hole, 4: Pipe, 5: Joint part,
6: Nozzle, 7: Pipe, 8: Joint part, 9: Small hole, 10: Pipe, 11: Joint part, 12: Nozzle, 13: Housing, 1
4: Joint part, 15: Control valve, 16: Nozzle, 17: Pipe element, 18: Burner nut block, 19: Flange part, 20, 21: Conical surface part, 22: Nozzle, 23: Port, 24: Burner nut surface , 25: Nozzle, 26: Block rear end, 27: Block tip, 28: Engagement part, 2
9: Annular chamber, 30: Fuel gas supply port, 31: Air supply port.

Claims (1)

[Scope of Claims] 1. A system that opens downstream of the intersection of a water supply passage and an air supply passage that intersect with each other in such a manner that water is introduced into a continuous annular air flow through a small hole. a first nozzle for injecting a mixture of gaseous fuel, air or steam, and gaseous fuel, air or steam supply passages that intersect with each other in a manner that introduces the liquid fuel through small holes into an annular continuous flow of gaseous fuel, air or steam; a second nozzle that opens in an annular manner around the first nozzle downstream of the intersection with the liquid fuel supply passage and injects a mixture of gaseous fuel, air, or water vapor and liquid fuel; A burner characterized in that it has a third nozzle that is annularly opened around the nozzle and injects air. 2. In an embodiment in which water is introduced into the continuous annular air flow through small holes, a first opening is provided on the downstream side of the intersection of the water supply passage and the air supply passage, which intersect with each other, and injects a mixture of water and air. a nozzle, a gas fuel, air or water vapor supply passage and a liquid fuel supply passage that intersect with each other in a manner that introduces the liquid fuel through a small hole into an annular continuous flow of gaseous fuel, air or water vapor; a second nozzle opening in an annular manner around the first nozzle downstream of the intersection and injecting a mixture of gaseous fuel, air or water vapor and liquid fuel; and an annular opening around the second nozzle. a third nozzle that opens and injects air; a fourth nozzle that opens annularly around the third nozzle and injects air; and a fourth nozzle that opens annularly around the fourth nozzle and injects gas fuel and air. or a fifth nozzle for injecting a mixture of gaseous fuel and air.