JPS636765B2 - - Google Patents

Description

Detailed Description of the Invention The present invention utilizes the centrifugal force of a rotating body to atomize liquid fuel, disperse it dropwise onto the inner surface of a vaporization cylinder, and gasify it.
Regarding a so-called rotary spray type liquid fuel combustion device that burns the gasified fuel in a burner section, the width of dispersion and dripping of fuel particles is expanded to prevent a local temperature drop on the inner surface of the vaporization cylinder and to prevent tar generation.
By dividing the fuel particles into fine particles and obtaining a uniform distribution pattern, the effective use of vaporization heat and the mixing of primary air and vaporized gas are promoted, thereby stabilizing combustion.

Conventionally, this type of rotary spray burner has many advantages in various respects, but on the other hand, tar is deposited in the vaporizing section, which has a negative effect on combustion itself, and eventually leads to a state in which combustion is no longer possible. There was a drawback. A conventional example will be explained below with reference to FIGS. 7 to 11.

In FIG. 7, 101 is a burner motor,
The rotating shaft 102 has a cone 103 and a rotating plate 104.
is fixed. 105 is a liquid fuel supply port, and 106 is a vaporization cylinder. Next, the effect will be explained.

The tapered cone 103 and rotary plate 104 attached to the rotating shaft 102 of the motor 101 rotate together, and when liquid fuel is supplied from the liquid fuel supply port 105 to a part of the tapered cone 103, the liquid fuel becomes tapered. It adheres to the surface of the cone 103, climbs up to the surface of the tapered cone 103 due to the action of centrifugal force, is sprayed from around the rotary plate 104, is spread on the inner surface of the vaporizer cylinder 106, and is evaporated and gasified. However, in this example, since the rotary plate 104 is a relatively thin flat plate, the fuel is sprayed on the inner surface of the vaporization tube 106 in a linear or narrow band shape, so that the inner surface of the vaporization tube 106 is locally sprayed. This caused a decrease in vaporization efficiency and caused the generation of tar. Furthermore, since it does not have a mixing plate, the mixing of primary air and vaporized gas is extremely poor.
It had the disadvantage of easily generating red flames.

In the example shown in FIG. 8, rotating blades 107 that rotate integrally with the rotating plate 104 are added to the outside of the rotating plate 104, and the blades 107 catch some of the fuel particles scattered from the rotating plate 104. By re-spraying from the outer peripheral edge of the fuel gas, the fuel gas and air are mixed with each other by the air stirring action of the blades 107 while spreading the spray pattern in the axial direction. Since the particle pattern is in the form of a thin plate, the blade plate 10
7 has a limited effect, and the spraying pattern varies slightly depending on the angle and surface condition of the vane plate 107, so that a consistent distributed dropping effect cannot be obtained.

In the example shown in FIG. 9, a foam metal having open cells is used as the rotating body 108, liquid fuel is supplied to the inner surface 109 of the rotating body 108, and liquid fuel is transferred from the outer circumferential surface of the foamed metal rotating body 108 to the rotating body due to centrifugal force. Although it was expected that the dispersion width would be similar to that of No. 108, in reality, due to subtle differences in the bubble distribution of individual foams and the influence of centrifugal force, there is a tendency for the bubbles to concentrate in specific parts of the outer circumferential surface. There is also large variation in particle size. Furthermore, when extinguishing a fire, the oil impregnated in the foam has the effect of causing a fire extinguishing odor and generating a large amount of CO.

In order to prevent tar formation in the evaporation section, one measure is to make the fine particles of liquid fuel hit the evaporation surface as widely and uniformly as possible, that is, to lower the evaporation load rate on the evaporation surface. 1st
This will be explained in Figure 0.

103 is a cone, and a plurality of rotating disks 12
2a to 122e are fixed at regular intervals in the axial direction of the cone 103. Furthermore, cone 103
Openings 125b to 125e are provided at the contact portions of the rotary disks 122a to 122e. 105
is the fuel supply port.

Next, the effect will be explained. The fuel dripped into the cone 103 from the fuel supply port 105 crawls up the surface of the cone 103, and some of the fuel reaches the rotating disk 122e.
It scatters from the tip of the circumference. Other fuels are at opening 12
5e, ascends the surface of the cone 103, and gradually scatters from the circumferential tips of the rotating disks 122d to 122a, respectively.

By scattering fine particles using a plurality of rotating disks in this manner, it is possible to prevent (reduce) tar formation in the vaporization section. However, cone 1
03 and the rotating bodies 122a to 122e are complicated in structure, and the dimensional accuracy of the openings 125b to 125e during assembly is difficult to achieve, making management difficult and problematic in practice.

The present invention uses a rational and simple structure to widen the dispersion width of liquid fuel and atomize it, as well as promote mixing of the particles with air, thereby solving the drawbacks of the conventional examples.

Specifically, the present invention provides a rotary spray burner that vaporizes (gasifies) liquid fuel fine particles sprayed by a rotating body on a vaporizing surface, in which a hollow substantially conical rotating body is provided on the large-diameter end surface of a tapered cone. The load on the inner surface of the carburetor cylinder is reduced by installing multiple swirl vanes around the rotating body and evenly rotating and spraying fine fuel particles from multistage openings on the surrounding surface of the rotating body. This prevents tar formation in the vaporization section, promotes mixing of air and vaporized gas, and stabilizes combustion.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

In FIG. 1, 1 is a cylindrical motor case, which is connected to a burner case 2 and a combustion tube 3 in this order, with a heat-resistant packing 4 interposed between the combustion tube 3 and the burner case 2. . 5 is a motor installed in the motor case 1, and one end of the motor shaft 6 protrudes into the burner case 2 and extends to a position close to the combustion tube 3.

In addition, an air intake port 7 is provided on the side of the motor case 1.
A plurality of communication holes 8 communicating with the inside of the burner case 2 are provided at the periphery of the end face portion on the burner case 2 side. 9 is the rotating shaft 6 in the burner case 2.
A turbo fan is installed and fixed in the middle, and has multiple stages (two stages in Fig. 1), and a guide vane 10 fixed to the burner case 2 is provided on the discharge side of each turbo fan 9. . The combination of these turbo fans 9 and guide blades 10 constitutes an air blowing chamber 11, and by increasing the number of stages in the combination, the static pressure can be increased. 12
is a partition plate fixed to the burner case 2 at an appropriate distance from the final stage guide vane 10, and in the center thereof is a relatively large primary air inlet 1 through which the rotating shaft 6 passes.
3, and several small secondary air inlets 14 are provided at its periphery. That is, the separation chamber 1 is located between the final stage guide vane 10 and the partition plate 12.
5, the blown air that has passed through the guide vane 10 at the final stage is divided into two in this branch chamber 15, one of which passes through the primary air inlet 13 of the partition plate 12 and becomes primary air, and the other The air passes through the secondary air inlet 14 of the partition plate 12 and becomes secondary air. Reference numeral 16 denotes a cylindrical vaporizing cylinder installed in the space on the leeward side of the partition plate 12 in the burner case 2, and is made of a metal material with good thermal conductivity such as aluminum die-casting. A sheathed heater 17 is embedded in the peripheral wall near the end. One end of this vaporizing cylinder 16 is attached to the partition plate 12 via a heat insulating packing (not shown), and the other end is in close contact with the burner case 2. The internal space of this vaporizing cylinder 16 is a vaporizing chamber 18 communicating with the primary air inlet 13, and furthermore, the space between the vaporizing cylinder 16 and the burner case 2 is a secondary air chamber 19 communicating with the secondary air inlet 14. The secondary air flows into the combustion chamber 2 through this outlet 20.
It is designed to flow into 1.

On the other hand, a tapered cone 23 is attached to the tip of the rotating shaft 6 protruding into the vaporization chamber 18, and a hollow, substantially conical rotating body 22 is fixed to the large diameter end of the tapered cone 23. The end is an open end that gradually becomes larger in diameter toward the smaller diameter side on the outer periphery of the tapered cone 23. Next, reference numerals 22a to 22d in FIG. 2 are openings provided around the rotating body 22, and the opening areas are appropriately adjusted in order to uniformly inject the atomized fuel. 24 is a plurality of stirring blades provided in the radial direction around the open end of the rotating body 22;
It promotes vaporization (gasification) on the vaporization surface of the vaporization tube 16, and also removes air from the primary air inlet 13 (secondary air inlet).
This improves the mixing of the gas (arrow in the figure) and the vaporized fuel.

Note that the fuel is sent from a pump (not shown) through the liquid fuel supply pipe 26;
This pipe 26 is guided slightly above the rotating shaft 6 through the flow dividing chamber 15, where it is bent into an inverted U-shape, and its tip opening is connected to a conical tapered cone 2.
It is located close to and above 3. Note that the outer peripheral portion 12 of the primary air inlet 13 provided in the partition plate 12
a is formed in a tapered shape so as to slightly protrude into the vaporization chamber 18, and the primary air inlet 13 is connected to a cone 23.
The opening is towards the liquid fuel supply point. 2
A burner head 7 is installed and fixed near the opening at the tip of the vaporization tube 16 facing the combustion tube 3, and has a plurality of thin holes.A flame rod 28 for combustion detection is positioned in front of the burner head 7 in the combustion flame A. An ignition electrode 29 protrudes from the combustion tube 3.

In the above configuration, when starting combustion, the sheathed heater 17 is first energized to heat the vaporization tube 16. When the temperature of the vaporizer cylinder 16 rises to a set temperature sufficient to vaporize the liquid fuel due to this energization, the burner thermometer (not shown) is turned on, the motor 5 is started, and as the rotating shaft 6 rotates, the turbo fan is activated. 9, cone 22, swinging board 23,
The stirring blade 24 rotates. When the turbo fan 8 generates wind pressure, the combustion air first flows through the air intake port 7→
The inside of the motor case 1 → the communication hole 8 → the air blowing chamber 11, and then it is divided into two parts in the branching chamber 15. One becomes the primary air that enters the vaporization chamber 18 through the primary air inlet 13, and the other becomes the secondary air. Secondary air enters the secondary air chamber 19 through the air inlet 14. Simultaneously with the start of this air blowing, the fuel pump operates, and liquid fuel passes through the liquid fuel supply pipe 26 to the tapered cone 23.
Supplied on top. Since the tapered cone 23 has a conical shape, the liquid fuel supplied onto the tapered cone 23 is transferred to the larger diameter side of the tapered cone 23 by rotational centrifugal force, and then transferred to the rotating body 2.
2, and a portion of the fuel is first sprayed from the opening 22a. (In this case, since the openings are arranged in four stages in the axial direction, the ideal amount of fuel is about 1/4 to 1/5.) Furthermore, the remaining fuel rises up the inner surface of the rotary body 22 and flows through the openings 22b to 1/5. As a result, all the fuel is sprayed from the peripheral outer surface of the rotating body 22 and scattered toward the vaporizing surface of the vaporizing cylinder 16. Since the vaporization tube 16 has already been heated as described above, the atomized fuel instantly becomes vaporized fuel. On the other hand, the primary air inlet 13 is provided in the vaporization chamber 18.
Since the primary air is sent into the vaporization cylinder 16 from the fuel tank 16, the vaporized fuel and the primary air are mixed to form a mixed gas flow. This mixed gas flow flows through the burner head 27.
If the flame is ignited by the ignition electrode 29, a blue combustion flame A is formed in the burner head 27. The combustion detection flame rod 28 then detects that combustion is in progress. on the other hand,
The secondary air sent to the secondary air chamber 19 is
The air passes through the outer periphery of the air, enters the combustion chamber 21 from the secondary air outlet 20, and contributes to combustion.

In this embodiment, the positions of the openings 22a to 22d on the surface of the rotating body 22 are set in multiple stages in the direction of the rotation axis 6, and the opening areas of the openings 22a to 22d are appropriately adjusted. is not concentrated in one place, but is evenly dispersed and scattered on the vaporization surface of the vaporization cylinder 16, and is quickly gasified by receiving heat from the wall surface.

At the same time, a part of the air from the primary air inlet 13 (solid arrow in FIG. 2) is moved along the vaporizing surface of the vaporizing cylinder 16 to the burner head 27 by the operation of the stirring blade 24 provided around the open end of the rotating shaft 22. Flows to the side. At this time, the diffusion layer of fuel molecules near the evaporation surface of the properly dispersed oil film is destroyed and becomes thinner, so the velocity gradient between the oil film and the surrounding air flow increases, and the vaporization rate from the evaporation surface of the vaporization tube 22 increases. It gets even faster. Further, at this point, the vaporized fuel and the primary air are mixed.

Furthermore, in this embodiment, in addition to atomization by centrifugal force as described above, the primary air inlet 13
Since the flow of air is introduced into the openings 22a to 22d, the jetting speed of the fine particles jetted out from the openings 22a to 22d is increased, and atomization is further promoted.

Although the openings 22a to 22b are described as having a slit shape in the embodiment, the shape is not limited to this, and the same effect can be achieved with a small diameter circle or the like. Further, in this embodiment, the rotating body 22 and the stirring blade 24 are separate bodies, but as shown in FIG.
The stirring blades 24 may be cut and raised at the open end extensions of the openings 2 and formed integrally.

As described above, according to the present invention, in the rotary spray burner that vaporizes liquid fuel particles on the vaporization surface,
A hollow, substantially conical rotating body is attached to the large-diameter end face of the tapered cone, and a plurality of stirring blades are provided in the radial direction around the open end of the rotating body. By spraying fine fuel particles evenly onto the vaporization surface, the following effects can be obtained.

(1) While uniformly supplying liquid fuel to the wide vaporization surface of the vaporization cylinder, by forcing airflow along the vaporization surface, the vaporization speed is accelerated and the temperature of the vaporization surface is extremely reduced. Since it can be vaporized at around the set temperature, tar precipitation can be prevented and the life of the burner can be extended.

(2) Since the liquid fuel can be made into fine particles, it can be mixed well with the combustion air and combustion can be stabilized.

(3) The temperature of the vaporization surface is normally set to a temperature slightly higher than the fuel evaporation temperature in consideration of the amount of heat taken away during fuel evaporation, but in the present invention, the vaporization area is widened to reduce the vaporization load. Therefore, it is possible to shorten the preheating time of the vaporizing section and shift to steady operation.

(4) Conventionally, this type of combustor was mechanically suitable for low combustion (6000kcal/h), but by effectively utilizing the vaporization surface (dispersion and atomization of spray particles), high combustion has been achieved. It is also easy to handle large quantities.

(5) Since the speed of vaporization on the vaporization side is accelerated, the response during ignition and extinguishing is quick and odor is reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the liquid fuel combustion device of the present invention, Fig. 2 is a sectional view of the vaporization section in the same device, Fig. 3 is a spray distribution diagram of the vaporization section, and Fig. 4 is the same device. 5 is a front view of the rotating body, FIG. 6 is a front view of another embodiment of the rotating body, and FIGS. 7, 8, 9, and 10 are respectively FIG. 11 is a configuration diagram showing a conventional example, and is a spray distribution diagram of the rotating body in FIG. 10. 6... Rotating shaft, 17... Sheathed heater, 13...
...Primary air inlet, 16... Vaporization cylinder, 22... Rotating body, 22a-22d... Opening, 23... Cone, 24... Stirring blade, 26... Liquid fuel supply pipe, 27... Burner head.

Claims (1)

[Claims] 1. A rotating shaft is arranged concentrically with a vaporizing cylinder equipped with a heater, a tapered cone and a rotating body are attached to the rotating shaft for scattering fuel oil to the vaporizing cylinder, and fuel is placed near the surface of the tapered cone. A supply pipe is arranged, one end of a hollow substantially conical rotating body is fixed to the large diameter side end surface of the tapered cone, and the other end is an open end that gradually increases in diameter toward the small diameter side of the tapered cone, A liquid fuel combustion device, wherein a plurality of stirring blades are provided in a radial direction from the periphery of the open end, and openings are provided in multiple stages around the rotating body in the axial direction of the rotating shaft.