JP2923749B2 - Spray type combustor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray combustor for mixing liquid fuel sprayed from a fuel spray nozzle with air and burning the mixture.

[0002]

As shown in Prior Art FIG. 4, the inner cylinder b bottomed tubular into the outer cylinder a is provided, thereby forming a vent path c between the outer cylinder a and the inner cylinder b, the inner cylinder b around the fuel spray nozzle d formed on the, by providing an annular stabilizer e the inner peripheral wall of the inner cylinder b in front of the fuel spray nozzle d, to supply the blower or al the fuel sprayed from the fuel spray nozzle d A spray-type combustor for mixing and burning air in the inner cylinder b is known, and the combustion ignites the air-fuel mixture in the inner cylinder b and forms the majority of the flame in front of the inner cylinder b while forming the flame. The flame is kept at an appropriate temperature for combustion.

[0003]

To explain the combustion of the liquid fuel, the fuel droplets during spraying are vaporized by their own combustion heat and burn while forming a mixed layer of vaporized fuel and air around them. Therefore, as shown in FIG. 4, as the angle becomes larger from the spray angle, that is, from θ1 to θ3, not only does the mixing time of the atomized fuel and air become shorter, but also the time that the fuel droplets are kept in the flame becomes shorter. Therefore, the time during which the fuel is kept at a high temperature in the flame is shortened, and the vaporization of the fuel droplet is difficult to progress.
Furthermore, the outer peripheral portion of the spray pattern is out of the flammable range due to excessive air, and is not burned, but is discharged to the outside in the form of fuel droplets. An object of the present invention is to obtain a spray-type combustor free of such a problem.

[0004]

According to the first aspect of the present invention, a bottomed inner cylinder is provided in an outer cylinder connected to a blower, and a ventilation path is provided between the outer cylinder and the inner cylinder. A fuel spray nozzle is provided at the center of the inner cylinder, and a fuel spray nozzle is provided in the center of the inner cylinder, and a fuel sprayed from the fuel spray nozzle is mixed with air supplied from a blower in the inner cylinder and burned. It is characterized in that a narrowed portion having a large radius of curvature is provided inward at the front end, and by having such a configuration, it is possible to concentrate the flame in the central portion at the narrowed portion.

[0005] The invention described in claim 2 of the present application is claim 1
In the invention, the tip inner diameter of the narrowed portion is characterized by a substantially half of the inner cylinder diameter, by providing such a configuration, without interfering with the formation of the flame, it is possible to narrow the flame.

[0006]

Embodiments of the present invention will be described with reference to the drawings. In the drawing, reference numeral 1 denotes an outer cylinder provided at a discharge port 2a of a blower 2, 3 denotes a bottomed cylindrical inner cylinder provided in the outer cylinder 1, and an inner circumference of the outer cylinder 1 and an outer circumference of the inner cylinder 3 are shown. A combustion path is formed between the inner cylinder 3 and an air hole 5a provided in the peripheral wall of the inner cylinder 3 and an air hole 5b provided in the bottom wall. 6
Is a fuel spray nozzle provided forward in the center of the inner cylinder 3, 7 is a spark plug facing the vicinity of the fuel spray nozzle 6, 8 is an inner periphery of the inner cylinder 3 in front of the fuel spray nozzle 6. A stabilizer formed of an annular plate 8a having an opening 8b at the center thereof, the stabilizer 8 being cut and raised in the radial direction, and having a radial slit 8c and a slit 8c communicating with the opening 8b at an inner end. And a blade 8d that covers the front surface of the inner cylinder 3 so that the blade 8d is inclined by 10 ° to 15 ° with respect to the annular plate 8a to form a swirling flow along the circumferential direction of the inner cylinder 3 in the airflow passing through the slit 8c. did.

The present invention relates to a spray-type combustor having such a structure, in which a narrowing portion 9 is provided at the front end of the inner cylinder 3 so as to be curved inwardly in an arc shape to narrow the opening area. A throttle member 10 having a throttle section 9 formed by inwardly bending an arc is attached to the front end of the inner cylinder 3, and the throttle member 10 is provided so as to protrude forward from the front end of the air passage 4. Was. The aperture member 10 has a rear end inner diameter A
Is set to about 10 cm to be fitted to the outer periphery of the front end of the inner cylinder 3, and the inner diameter B at the tip is set to about 5 cm, which is approximately の of the cross-sectional area of the inner cylinder 3. It is desirable that the length C of the constricted portion 9 be equal to or more than 1/2 of the inner diameter B of the distal end.

When the fuel is sprayed, a portion of the atomized fuel sprayed from the fuel spray nozzle 6 which is close to the outer periphery collides with the inner surface of the throttle portion 9 and is discharged from the inner cylinder 3 in a state of a fuel droplet. it is that a small pop out. Further, the flame concentrates at the central portion at the throttle portion 9, the temperature of the flame is maintained at a high temperature, and the vaporization of the fuel droplet proceeds. In particular, even when carbon adheres to the fuel spray nozzle 6 and the fuel supply amount is reduced, or the fuel supply amount is reduced by the proportional control or the like and the fuel supply amount is reduced and the mixture ratio becomes lean, the high temperature state is maintained. . As a result, generation and emission of unburned components due to a decrease in the temperature of the flame can be suppressed. In addition, by providing the throttle portion 9 having the large radius of curvature, a smooth flow of the air-fuel mixture can be created along the inner surface of the throttle portion 9, and the air-fuel mixture is separated or the air-fuel mixture stagnates in the throttle portion 9. Can be avoided, and the adhesion of carbon to the inner surface of the narrowed portion 9 can be suppressed.

Reference numeral 11 denotes ventilation holes arranged in a line at the front end of the ventilation passage 4 so as to surround the throttle member 10.
The outer periphery of the flame discharged from the tip of the throttle member is wrapped by the air blown out from No. 1. In this way, the supply of the secondary air can be effectively performed, and the propagation of the combustion noise can be suppressed. Vent 1 for performing such an operation
It is desirable that one diameter be equal to or less than １ ／ of the length C of the constricted portion 9. In the conventional combustor, a front end opening of the inner cylinder 3 and a vent hole 10 provided on the front surface of the air passage 4 surrounding the front end opening are provided.
And the fuel that has been atomized,
It goes around to one side and burns while forming a flame. However, there was a problem that tar was attached in the vicinity of the ventilation hole 11 because the temperature was relatively low. In the embodiment of the present invention, the diaphragm member by protrudes forward from the front end of the air passage 4, because the tip opening and the vent hole 11 of the inner cylinder 3 is separated, it can cause flame vent 11 parts As a result, tar does not adhere to the periphery of the vent hole 11. In addition, the ventilation holes 11 arranged in a row at the front end of the ventilation passage 4 so as to surround the diaphragm member 10 are arranged in a single row, but the invention is not limited to this, and the ventilation holes 11 may be provided in double inside and outside.

[0010]

According to the first aspect of the invention, of the fuel atomized from the fuel spray nozzle and atomized, a portion of the fuel close to the outer periphery of the spray pattern collides with the inner surface of the throttle portion, so that the fuel droplets are formed. In this state, it is less likely to jump out of the inner cylinder. Further, since the flame is concentrated at the central portion at the throttle portion, the temperature of the flame is maintained at a high temperature, and the vaporization of the fuel droplets is easy to proceed. Further, even when the supply amount of fuel decreases as compared with the supply amount of air, and the mixture ratio becomes lean, the flame can be maintained at a high temperature, and the generation and emission of unburned components due to a decrease in the temperature of the flame can be suppressed. Moreover,
Since the constricted portion is curved inwardly in an arc shape, a flow of the air-fuel mixture can be made smoothly along the inner surface of the constricted portion, and separation of the air-fuel mixture or stagnation of the air-fuel mixture in the constricted portion can be avoided. Thus, the adhesion of carbon to the inner surface of the narrowed portion can be suppressed.

According to a second aspect of the present invention, in the first aspect of the present invention, the cross-sectional area of the narrowed portion is set to approximately half of the cross-sectional area of the inner cylinder, so that the formation of the flame can be surely prevented. Flames can be squeezed.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of the invention.

FIG. 2 is a front view of FIG. 1;

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a partially cutaway side view showing a conventional example.

[Explanation of symbols]

 Reference Signs List 1 outer cylinder 2 blower 3 inner cylinder 4 ventilation path

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F23D 11/24

Claims (2)

(57) [Claims] 1. A bottomed cylindrical inner cylinder is provided in an outer cylinder connected to a blower, a ventilation path is formed between the outer cylinder and the inner cylinder, and a fuel spray nozzle is provided at the center of the inner cylinder. In a spray-type combustor that mixes and burns the fuel sprayed from the fuel spray nozzle with air supplied from a blower in an inner cylinder,
A spray type combustor characterized in that a narrowing portion is provided at the front end of the inner cylinder so as to curve inwardly in an arc shape to reduce the opening area. 2. The spray-type combustor according to claim 1, wherein the inner diameter of the tip of the throttle is approximately one half of the inner cylinder diameter .