JPS58182010A - Burner for liquid fuel - Google Patents

Abstract

PURPOSE:To provide the titled device which has a very high atomizing efficiency and an excellent atomizing property and is adapted to perform an efficient and perfect combustion of a liquid fuel, by improving the shape of a colliding body. CONSTITUTION:The apex part of an colliding body 9 is formed in an inverted cone, and a colliding surface 8 makes an acute angle with an adjacent colliding body surface 8a around the impinging surface 8. Thus, when the liquid fuel spread to make a liquid film by the colliding surface 8 is flown into a space, it only makes contact with a sharp edge part 10 which is different from the case of a conventional cylindrical colliding body, and thereby, the reduction in a speed in a radial direction is made very low. Further, because of the shape described above, the surface tension of the liquid fuel exceeds an affinity between the liquid fuel and the colliding body side 8a, and the liquid fuel is prevented from wetting the colliding body side 8a. Thus, the speed in the radial direction within the liquid film is approximately maintained, the formed liquid film is thinned, very fine atomized particles are formed, and simultaneously, nearly all of the fuel jetted through a nozzle may be atomized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid fuel combustion device that atomizes and burns liquid fuel using the collision atomization phenomenon.

Collision atomization has been widely studied in the past, and involves ejecting liquid from a nozzle having fine holes and colliding it with an impactor to atomize the liquid.

The liquid ejected from the nozzle initially has a smooth cylindrical shape, but gradually begins to vibrate, and eventually breaks up into droplets. For collision atomization, there are two methods: one in which the jets collide in a smooth flow region, and the other in a droplet flow region. The present invention relates to the former method in which the jets collide into collision 2 in the smooth flow region. This method has much better atomization efficiency than the method of colliding in the droplet flow region (
, it has advantages such as being able to reduce the distance from the nozzle to the collision weight. In other words, in the method of colliding in the droplet flow region,
Only about half of the liquid ejected from the nozzle can be atomized, and the device tends to be large.

However, even with the method of colliding in a smooth flow region, the atomization efficiency is 1
Some of them, not just 00, will stick to the collision object. 1. The diameter of the spray particles produced was relatively large, and various measures were required to achieve complete combustion.

The present invention was made in order to improve the drawbacks of collision atomization in which collisions occur in such a smooth flow region, and aims to improve the atomization efficiency and atomization characteristics. To provide a liquid fuel combustion device that can efficiently and completely burn liquid fuel.

An embodiment of the present invention will be described below with reference to the drawings.

A conventional liquid fuel combustion device will be explained with reference to FIGS. 1 and 2. The liquid fuel is pressurized by the pump 1 and is ejected from the pores of the nozzle 2. The collision body 3 has a circular collision surface 4
is attached to the nozzle 2 so that it is located perpendicular to the jet in the smooth flow region of the jet. The collision surface 4 is polished to a mirror surface so as not to reduce the momentum of the fuel due to friction. The fuel jet ejected from the nozzle 2 collides with the collision surface 4 to form a liquid film, which is split from the periphery of the liquid film to become fine particles. The generated fine particles are supplied by a blower fan 6, transported by an air flow rectified by a rectifying grid 6, and burned at a flame port 7.

In order to achieve complete combustion, the smaller the particle size is, the better, and for this purpose, the thickness of the liquid film formed on the collision surface 4 must be reduced. Since the liquid film thickness is determined by the radial velocity of the liquid fuel within the liquid film, it is necessary to preserve the momentum of the fuel jet at the collision surface 4 as much as possible. Therefore, in order to reduce the friction on the collision surface 4, the collision surface is made into a mirror surface. However, when the liquid film that spreads on the collision surface 4''2 jumps out from around the collision surface 4 into space, its radial velocity is reduced due to the affinity between the collision body side surface 4a and the liquid fuel, and the collision body side surface 4a is It will get wet. For this reason, the thickness of the liquid film formed becomes large, and the particle size of the generated spray cannot be made sufficiently small. Further, there is a drawback that all of the liquid fuel ejected from the nozzle 2 cannot be atomized, and a portion of it adheres to the side surface 4a of the collision body, causing dripping.

The present invention has been made to improve these drawbacks, and by improving the shape of the collision body, it has realized improvements in atomization characteristics and atomization efficiency. An embodiment of the present invention is shown in FIGS. 3 and 4, in which the same parts as in FIG. 1 are denoted by the same numbers as d.

The collision surface 8 is circular and polished to a mirror surface, as in the past, or the tip of the collision body 9 is shaped like an inverted cone, so that around the collision surface 8, the collision surface 8 and adjacent collision bodies Side 8a
forms an acute angle. For this reason, when the liquid fuel spread into a liquid film on the collision surface 8 is ejected into space, it has sharp edges 1.
Since the collision body only makes contact with the cylindrical collision body, the decrease in velocity in the radial direction is extremely small, unlike in the case of a conventional cylindrical collision body.

Moreover, by adopting such a shape, the surface tension of the liquid fuel overcomes the affinity between the liquid fuel and the side surface 8a of the collision body, and the liquid fuel wets the side surface 8a of the collision body. The radial velocity of the nozzle is almost conserved, the thickness of the liquid film formed is reduced, very small atomized particles are produced, and it is possible to atomize almost the entire amount of fuel injected from the nozzle. .

The nozzle 11 used in this example has a pore diameter of 80 μm, and the collision surface 8 has a diameter of 1 μm. Unfortunately, the length of the smooth flow region of the fuel jet obtained by the nozzle 11 was approximately 70 degrees.

This is determined by the shape of the nozzle pore, the fuel jet speed, and external disturbances, but the collision surface 8 must always be located within this region. In this example, the distance from the nozzle outlet to the collision surface 8 was 40 mm. Collider 9
The vicinity of the collision surface 8 is shaped like an inverted cone, and the angle between the collision surface 8 and the collision body side surface 8a at the edge portion 1o around the collision surface 8 is 46.
°. In this embodiment, the collision surface 6 8 has a circular flat end shape, but the present invention is not limited to this. For example, even if a hemispherical convex surface is used as the collision surface 8, the same effect can be obtained. is obtained.

Further, since the pressure applied to the liquid fuel determines the amount of combustion and the length of the smooth flow region, it may be determined by taking these into consideration.

However, from the viewpoint of atomization characteristics, it is desirable to set the pressure P and the diameter of the liquid film formed at the collision surface 8 in a region where the relationship dD/dP (O) holds. To explain the relationship, as the pressure P is gradually increased, the diameter of the liquid film formed initially increases as P increases.In other words, in this region, dD/dP)○,
The liquid film formed is a smooth laminar flow film, and spray particles are almost exclusively generated around the liquid film. However, when P is further increased, the liquid film formed becomes a turbulent film, and dD/dP
(It will be ○. In this region, spray particles will be generated in areas other than the periphery of the liquid film, and the particle size at this time will be smaller than the particle size generated from the laminar flow membrane. Therefore, the pressure P will be It is desirable to set it within this area of 7.

As is clear from the following explanation, the present invention has an extremely simple structure and achieves a fuel atomization means having extremely high atomization efficiency and good atomization characteristics, thereby efficiently and completely converting liquid fuel. The present invention provides a liquid fuel combustion device that can burn liquid fuel, and its industrial value is extremely high.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of a conventional liquid fuel combustion device, FIG. 2 is an enlarged sectional view of section A in FIG. 1, and FIG. 3 is a side view of a conventional liquid fuel combustion device according to an embodiment of the present invention. FIG. 4 is an enlarged sectional view of section B in FIG. 3. 6...Blower fan, 7...Flamer mouth part, 8...
...Collision surface, 8a...Collision surface side, 9...
... Colliding object.

Claims (1)

[Claims] A liquid fuel combustion device comprising: a collision body that collides and atomizes liquid fuel, and configured such that a liquid fuel collision surface of the collision body and another constituent surface adjacent thereto form an acute angle.