JPS60200013A - Liquid fuel burner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a liquid fuel combustion device used in a heat source device as a small-sized domestic hot water supply/heating device.

Conventional Structure and Problems Conventionally, this type of combustion apparatus has been structured as shown in FIG. That is, the middle cylinder 9 having a large number of air ejection holes 14 on its side wall and the auxiliary combustion cylinder 10 are arranged substantially concentrically, and the liquid fuel atomization means are respectively arranged upright and adjacent to each other in the combustion chamber 6. The fuel is continuously supplied into the combustion chamber 6 from the atomization means 3, and the combustion air is supplied to the combustion chamber 6 by the blower mechanism 20 via the blower passage 21 and from each air jet hole 14 on the middle cylinder 9. . The fuel particles supplied by the atomization means 3 flow into the premixing region through the spray nozzle 12 on the auxiliary combustion cylinder 10, mix with the air jetted from the middle cylinder 9, and perform diffusion combustion initially, and then Combustion heat promotes high-speed vaporization and mixing of fuel, resulting in premixed combustion. However, combustion air circulates inside the middle cylinder 9, constantly exchanging heat (cooling), and the rise in temperature to a predetermined temperature is considerably suppressed. On the other hand, spraying,
The moment of the atomized fuel particles reaches the middle cylinder 9 and collides with it, which is much larger than the airflow in the combustion chamber 6, and some of them are re-liquefied and flow down to the bottom 8 of the combustion chamber.

As a result, a portion of the fuel that has re-liquefied and flowed down is vaporized due to the temperature within the combustion chamber 6, but remains at the bottom 8 of the combustion chamber and forms a pool. Furthermore, when igniting and extinguishing the fire, odors were generated and the mixture ratio of air and fuel was uneven, resulting in deterioration of exhaust gas. This phenomenon became more serious as the combustion device was made smaller and shifted to the high-load combustion side.

Purpose of the Invention The present invention is intended to solve the above-mentioned problems, and aims to improve the combustion characteristics by suppressing the re-liquefaction of fuel on the inner cylinder wall surface and the formation of a fuel pool at the bottom of the combustion chamber by flowing down, and by promoting smooth evaporation. purpose.

Structure of the Invention In order to achieve this object, the present invention has a double pipe configuration in which a blower pipe is inserted and opened near the bottom inside the middle cylinder.

This configuration minimizes the contact surface between the middle cylinder and combustion air to suppress heat exchange, and the double-pipe structure insulates the lower part of the middle cylinder as much as possible to suppress heat exchange.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on FIGS. 2 and 3.

In the figure, the fuel tank (not shown) has an oil supply pipe 1.
A fuel pump 2 and a spiral injection valve 3 as an atomization means are connected through the fuel pump 2, and the spiral injection valve 3 and the ignition electrode 4 are included in a support cylinder 5 and incorporated into a combustion chamber 6. . The main body is formed of an inner and an outer combustion tube 7, 7', which also constitute the combustion chamber 6. At the bottom 8 of the combustion chamber 6, there is a center tube 9, and at its outer periphery there is a middle tube 9. An auxiliary combustion tube 10 is provided upright. and a wall opening 11 of the combustion chamber 6.
The ends of the spiral injection valve 3 and the ignition electrode 4 are provided in the combustion chamber 6 through the auxiliary combustion tube 10, and the auxiliary combustion cylinder 10 has a sufficiently large spray hole 12 to prevent the fuel spray particles from colliding with each other.
In addition, a large number of circulation holes 13 are provided near the bottom 8 of the combustion chamber on the same circumference. Further, a large number of air jet holes 14 are provided around the side wall of the middle cylinder 9 in a tangential direction or gradually from the tangential direction to the right angle direction from the bottom to the top. With such a configuration,
In the upper part of the middle cylinder 9 in the combustion chamber 6, there is a combustion area a1, a premixing area b where fuel particles and vaporized fuel are forcibly mixed between the middle cylinder 9 and the auxiliary combustion f@'110, and the combustion chamber 6. An internal circulation area C is formed between the auxiliary combustion cylinder 10 and the auxiliary combustion cylinder 10 . Inside the middle cylinder 9, a joint pipe 16 (joint member) having a mounting flange 15 is connected approximately concentrically to the vicinity of the lowest stage of the air jet hole 14 to form a double pipe.

Combustion air is supplied to the middle cylinder 9 from a blower mechanism 20 composed of a motor 17, a fan 18, and a fan case 19 via a blower pipe 21.

In the configuration described in Section 2, first, the motor 17 is energized and the blower (
When the irj 20 operates, combustion air flows into the middle cylinder 9 via the blast pipe 21, and each air jet hole 1 on the middle cylinder 9
4 to the combustion area a1 and the premixing area to form a swirling flow. Further, each type of air at this time is supplied at a fixed ratio, with some of the air flowing through the recirculation area C into the circulation hole 13, and some air flowing into the premixing area from the spray hole 12 again.

After a certain time delay in the operation of the blower mechanism 20, the ignition electrode 4 is energized and a spark is generated. Thereafter, the liquid fuel pressurized by the operation of the fuel pump 2 is injected into the combustion chamber 6 from the spiral injection valve 3.
sprayed inside. The fuel is diffused and mixed in the swirling flow formed in the combustion chamber 6 by the air ejected from each of the ejection holes 14, and after reaching a certain mixing ratio and a certain temperature, it is ignited and combusted. Initially, it exhibits diffusion combustion, and then the heat of combustion causes multi-stage vaporization premix combustion using multiple single-hole flames. The temperature of the atmosphere and each component increases due to the generation of flame in the combustion chamber 6 and the convection of internally circulating gas due to combustion. The lower part of the middle cylinder 9 is a double pipe, which is thermally insulated and the contact surface with the combustion air is minimized, so that the drop in I2,111 degrees due to cooling by heat exchange is suppressed as much as possible. Therefore, a group of fuel particles that collide with a part of the middle cylinder 9 are heated on the middle cylinder 9 and complete vaporization, or they vaporize and evaporate as they flow down as a liquid stream and reach the bottom 8 of the combustion chamber and form a pool. will be suppressed as much as possible.

Next, another embodiment of the present invention will be described with reference to FIG.

In this embodiment, the mounting flange 15 in the embodiment described above is
The other essential structural functions are the same as those of the above-mentioned embodiments, except that a slope is provided.

Although the operation and shut-off are still exactly the same, by inclining the flage 15 and providing a slope, the pressure loss on the path of the air supplied from the blower mechanism 20 is suppressed as much as possible, and the middle cylinder can be operated with the same blowing capacity. 9 is effectively ejected and supplied into the combustion chamber 6 as swirling air.

As described in detail, according to the liquid fuel combustion device of the present invention, by arranging the blower pipe in a double pipe configuration inside the middle cylinder, the temperature drop in the middle cylinder is suppressed, and the collision fuel is suppressed. This suppresses the formation of a pool of particles at the bottom of the combustion chamber, and reduces combustion JJI gases, odors, HC, and C during steady combustion and during extinguishing.
It is possible to improve the characteristics of o.

[Brief explanation of drawings]

FIG. 3 is a partially enlarged view of the middle cylinder and the vicinity of the bottom of the combustion chamber in FIG. 2, and FIG. 4 is a partially enlarged view of the middle cylinder and the vicinity of the bottom of the combustion chamber showing another embodiment. . 3... Volute injection valve (liquid fuel atomization means), 6... Combustion chamber, 7.7'... Combustion tube, 9...・Middle cylinder, 10...Auxiliary combustion cylinder, 1
4...Air blowout hole, 15...Mounting flange, 16...Joint pipe (joint part side). Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Quotient 1, S

Claims (4)

[Claims] (1) A bottomed cylindrical combustion chamber is constituted by a middle cylinder, an auxiliary combustion cylinder, and a combustion cylinder, each having a large number of air ejection holes arranged on substantially concentric circles, and liquid fuel is provided through the opening provided in the combustion chamber. A liquid fuel combustion device comprising: an atomizing means facing into the combustion chamber; and an air blowing pipe inserted into the middle cylinder to form a double pipe structure near the bottom thereof. (2) The liquid fuel combustion device according to claim 1, wherein a joining member having a mounting flange is provided at the insertion opening end of the blast pipe between the opening end and the middle cylinder. (3) The liquid fuel combustion device according to claim 2, wherein the mounting flange is provided near the lowest stage of the air jet hole of the middle cylinder. (4) Claim 2 in which the mounting flange is sloped
The liquid fuel combustion device described in .