JPS5849812A - Combustion apparatus for liquid fuel - Google Patents

Abstract

PURPOSE:To completely burn liquid fuel, even if a fuel of low quality is used, and to reduce noise, as well as to make the combustion rate variable over a wide range, by feeding the primary air into a vaporizing chamber, so as to contact with the external periphery of liquid fuel which is approximately conically injected into the vaporizing chamber. CONSTITUTION:A nozzle 2, which is projected into a vaporizing chamber 3 from one end of the chamber 3 in order to inject liquid fuel into it, is provided to the approximately conical vaporizing chamber 3, of which one end is closed, while the other end is opened. The primary air is fed into the vaporizing chamber 3 from primary air feeding ports 7, so as to contact with the external periphery of liquid fuel which is injected approximately conically into the vaporizing chamber 3 from the nozzle 2. The secondary air is fed into mixed gas which flows out of the vaporizing chamber 3, from secondary air feeding ports in a downstream part against the open part of a vaporizing chamber 3. With such an arrangement, liquid fuel of low quality can be used, while the generation rate of soot, carbon monoxide, and the like, are very low, and complete combustion with blue flames can be available from the time immediately after ignition, in a liquid fuel combustor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid fuel combustion device configured to spray liquid fuel through a nozzle, vaporize the sprayed liquid fuel in advance, and then burn it.

A widely used method for burning liquid fuel is a spray combustion method in which it is mixed with air, then atomized and burned to promote vaporization.

However, the atomized liquid fuel, which has an extremely large momentum compared to gaseous fuel, is quickly forced to mix with the humid air stream. Therefore, considerable noise is generated due to the turbulence of this air flow and the difference in evaporation rate of each oil droplet, and if mixing with air is not done properly, a large amount of soot and carbon monoxide will be generated. A flaw that easily spreads is formed again n6
The flame is a diffusion flame of vaporized liquid fuel and air, and the flame length is large and the combustion chamber volume is large.

In order to overcome all of these drawbacks, the liquid fuel is vaporized, premixed with air, and then premixed and combusted, and this method has been known as the gunpot method. In this method, the atomized liquid fuel is vaporized by colliding with a solid wall that is heated by the heat of combustion. It becomes a pore flame and the temperature rise is insufficient, so complete combustion cannot be achieved, and there is a drawback that odor and soot are generated during the startup time.If low-quality liquid fuel is used, the residue in the liquid fuel may be left on the solid wall soil. It has the disadvantage that it accumulates. In addition, when the combustion amount is fully variable, it is difficult to hold the pore flame in the small combustion amount region, so there is also the drawback that the range of change in the combustion amount cannot be adjusted.

The present invention has been made in order to improve the conventional drawbacks, by supplying primary air into the vaporization chamber in contact with the outer periphery of liquid fuel jetted into the vaporization chamber from a nozzle in a substantially conical shape. To provide a liquid fuel combustion device in which low-quality liquid fuel can be used, complete combustion can be carried out by blue flame immediately after ignition, the amount of combustion can be varied over a wide range, and the noise is low.

Hereinafter, one embodiment of the present invention will be described with reference to all the attached drawings. In FIG. 1, liquid fuel is pressurized by a pump 1, supplied to a nozzle 2, and sprayed into a vaporization chamber 3 in a substantially conical shape. The vaporization chamber 3 has a substantially cylindrical shape with one end closed and the other end open, and the nozzle 2 projects into the vaporization chamber 3 from one end.

Combustion air is supplied by a blower fan 4 through five air volume regulators. - Medical Qi is ejected into the vaporization chamber 3 from a vibro, which is used as an example of a primary air supply port. Fig. 2 shows details of the inside of the vaporization chamber 3, where the vibro is opened in a direction substantially tangential to the outer circumference of the conical surface of the conical liquid fuel ejected by the nozzle 2, and the ejected primary air The liquid fuel is attracted to droplets on the outer circumference of the cone and mixed, and is ignited by the ignition electrode 7 to form a flame sound. The high-temperature combustion exhaust gas generated by this secondary combustion swirls and rises while contacting and mixing with the outer circumference of the upper cone.

- 10,000, because the opening 8 of the vaporization chamber 3 is narrowed and the nozzle 2 induces the spray at the base of the spray, the vaporization chamber 3
Due to the decrease in the static pressure in the lower part of the vaporization chamber 3, a circulating flow is generated in the vicinity of the wall of the vaporization chamber 3 from the upper part to the lower part, sucked into the spray cone at the lower part and again to the upper part. The combustion exhaust gas that has risen while coming into contact with the outer peripheral surface of the spray cone is sucked into the interior of the spray cone again by this circulation flow and mixed with the atomized liquid fuel. Since the spray and the combustion gas are sufficiently mixed in this way, the spray is quickly vaporized in the vaporization chamber 3, and the vaporization chamber 3 is filled with fuel vapor in a short time after the ignition. The fuel vapor flowing out from the opening 8 is mixed with secondary air supplied from the secondary air supply hole 9 to form a premixture.
It erupts from zero and burns with blue flame.

The primary combustion only needs to supply the amount of heat required to vaporize the atomized liquid fuel, and even including the loss due to heat radiation, the primary combustion 1 only needs to be about 10% of the total combustion amount, accounting for most of the combustion. is performed by secondary combustion. In the secondary combustion, premix combustion is performed.
Second, in addition to low noise, blue flame is formed and the flame length is short, it is possible to reduce the combustion load per unit volume by 7 people, and the volume of the combustion chamber can be reduced. In addition, it also improves the disadvantage that, unlike in conventional liquid fuel combustion equipment, liquid fuel in the form of droplets is present in the flame, which increases the local equivalence ratio and easily generates soot and carbon monoxide. It is possible to easily achieve complete combustion.

In addition, in the liquid fuel combustion apparatus configured as in this embodiment, the combustion exhaust gas generated in the secondary combustion and the sprayed liquid fuel are brought into direct contact and mixed, so it is similar to the conventional pot-type liquid fuel combustion apparatus. Since there is no need to fully heat the solid wall during ignition, the rise time after ignition is extremely short, and no odor or soot is generated immediately after ignition. However, if an attempt is made to vaporize the atomized liquid fuel by bringing it into direct contact with something extremely high-temperature, such as the heat of a flame or exhaust gas, the liquid fuel that has been exposed to high temperatures for a long period of time will usually undergo thermal decomposition. However, in this example, in order to avoid this,
- The liquid fuel sprayed on the outer periphery of the conical surface is blown off in the tangential direction by medical airflow, and this is combusted to form a flame at a position that does not come into direct contact with the conical surface, while at the same time swirling the combustion exhaust gas. By rapidly mixing with the surrounding gas, the temperature is lowered and then mixed with the sprayed liquid fuel. Therefore, no soot is generated.

As described above, this embodiment is fully applicable to plate-fin type heat exchangers, etc., which cannot be used in soot exchanges in any case. In addition, liquid fuel does not vaporize in solid wall soil, but mixes with high-temperature exhaust gas in the air and vaporizes, so even if low-quality liquid fuel is used, residue may accumulate. Moreover, since the residue of fine particles is oxidized and decomposed in the secondary combustion, they are not discharged as coarse particles.

In addition, in conventional pot-type liquid fuel combustion devices, when the combustion amount is varied, it is difficult to reliably hold the pore flame in the small combustion amount region, and the flame is easily extinguished. This is because the size of the air hole formed in the air supply hole is small and the amount of heat generated is suppressed to prevent the fuel from becoming too hot and causing red flames or soot. Because of that, the amount of combustion? This is because if the size is made smaller, the pore spacer gets closer to the wall, which increases heat loss from the flame to the wall and causes the flame to go out.

On the other hand, in the configuration of the present embodiment, the primary flame can be made considerably large, so that the flame does not go out in the small combustion amount region, and therefore it is possible to vary the amount of lower combustion phosphorus over a wide range.

As is clear from the above explanation, the present invention allows the use of low-quality liquid fuel, generates extremely little soot and carbon monoxide, and furthermore allows complete combustion with blue flames to occur immediately after ignition. In addition, the combustion amount can be varied over a wide range, and a low-noise liquid fuel combustion device can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a liquid fuel combustion apparatus according to an embodiment of the present invention, and FIG. 2 is a partially cutaway perspective view of the vaporization chamber shown in FIG. 2...nozzle, 3...vaporization chamber, 7...
...Pipe (-medical air supply port), 9...Secondary air supply port. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure 2

Claims (1)

[Claims] (1) A substantially cylindrical vaporization chamber with one end closed and the other end open, and a vaporization chamber Ω protruding into the vaporization chamber from one end.
, a nozzle for ejecting liquid fuel, a primary air supply port for supplying primary air into the vaporization chamber that is ejected from the nozzle into the vaporization chamber in a substantially conical shape and in contact with the outer periphery of the liquid fuel; and an opening in the vaporization chamber. and a secondary air supply port that supplies secondary air to the mixed gas flowing out from the vaporization chamber downstream. The liquid fuel combustion device according to claim 1, wherein the air supply port is formed of a plurality of pipes protruding into the vaporization chamber.