JPS5974415A - Liquid fuel combustion device - Google Patents

Abstract

PURPOSE:To prevent the accumulation of a large amount of tar on the vaporization surface of a vaporization cylinder to thereby secure a stabilized combustion condition for a prolonged period of time by a method wherein the vaporization surface is roughened and oxidized by an anode oxidation process to form a porous film thereon and the temperature of the vaporization surface is made higher than the film boiling temperature of the liquid fuel. CONSTITUTION:A vaporization cylinder 11 is heated by a preheating sheath heater 12. When the temperature of the vaporization cylinder 11 rises up to a temperature at which the liquid fuel film-boils, a motor 7 is started and a cone 8, a shake-off plate 9 and an agitating vane 10 rotate. Then, simultaneously with the initiation of ventilation, a fuel pump operates to supply the liquid fuel over the cone 8 through a supply pipe 17 so that the liquid fuel becomes oil drops of 100mum in grain size as it runs against the shake-off plate 9 and the agitating vane 10 and scatters toward the vaporization surface 18. In this case, primary air is supplied into the vaporization cylinder 5 where the air is mixed with the vaporized fuel to produce a gas mixture which flows through a burner head 15 to make a combustion flame 16. The vaporization surface 18 of the vaporization cylinder 11 roughened to 50mum, treated by an anode oxidation process in a nitric acid bath to thereby form the porous film thereon. Thus, when the vaporization surface of such structure is heated continuously, the amount of tar accumulated on the surface reduces.

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICATION The present invention relates to a liquid fuel combustion device, particularly to a vaporization section thereof.

Configuration of conventional examples and their problems The vaporizing surface of conventional vaporizing liquid fuel combustion equipment (Vl) is a smooth metal surface made of die-cast aluminum or machined, and its surface roughness is usually less than 10μ. This type of equipment has a cylinder structure and is characterized by easy combustion control, but it also produces vaporized residue (hereinafter referred to as tar) on the vaporization surface where the fuel evaporates. This has the disadvantage that the heat transfer from the vaporization surface to the fuel is reduced, the vaporization rate is reduced and pulsation occurs, and white smoke and odor are produced during ignition and extinguishment, inhibiting stable combustion. In particular, impurities such as denatured oil 9 heavy oil (peroxide,
When using fuel 3t+ containing organic acids, gum, etc., there was a drawback that a large amount of tar accumulated during short-time combustion.

OBJECTS OF THE INVENTION The present invention eliminates these conventional drawbacks, and aims to prevent a large amount of tar from accumulating on the vaporizing surface and ensure stable combustion over a long period of time.

In order to achieve the object of the present invention, the vaporizing surface is roughened and anodized, and the vaporizing surface temperature is made to be equal to or higher than the film boiling temperature to vaporize liquid fuel.

With this configuration, liquid fuel (for example, kerosene) that comes into contact with the vaporizing surface causes film boiling, becomes particulate, and evaporates while moving on the vaporizing surface.

At this time, if the vaporization surface is sufficiently smooth for the oil droplets as in the conventional example, the oil droplets come into point contact with the vaporization surface as shown in FIG. 1, and evaporate and vaporize while moving on the vaporization surface.

In the figure, 1 indicates an oil layer and 2 indicates a vaporization surface. In contrast, the vaporized surface of the present invention is roughened and anodized as shown in FIG.

This failure ■ The oil layer is in point contact at more points than in the conventional example, and is more likely to receive heat from the vaporizing surface 2, making it easier to evaporate.

■ Vaporizing surface 2 area is larger than the conventional example, achieving a medium level of 1rii.
Tar accumulation per product is reduced.

(2) The oxide film 3 formed by the anodic oxidation process is a porous film with a diameter of 100 to 3 ooZ and a number of pores of approximately 1.times.10@8, so that accumulated tar can be easily decomposed.

Due to these effects, tar accumulation is reduced.

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

In FIG. 3, numerals 4 to 6 are a cylindrical motor case, a burner case, and a combustion cylinder, which are connected in this order. 7 is a motor installed inside the motor case 4, and the shaft is a circular raccoon-shaped cone 8 inside the burner case 6, and a circular swing plate 9.
, is connected to the stirring blade 10. Reference numeral 11 denotes a cylindrical vaporizing cylinder placed in the burner case 5, and is made of die-cast aluminum. 18 is roughened to a surface roughness of 500μ,
This vaporization surface consists of a porous film anodized in sulfuric acid. 12 is a preheating sheathed heater embedded in the vaporization cylinder 11. Reference numeral 13 denotes a turbo fan fixedly attached to the middle of the motor shaft within the burner case 5, and in combination with a guide blade 14 fixed to the burner case 5 forms an air blowing chamber.

In the above configuration, when starting combustion, first, the preheating sheathed heater 12 is energized to heat the vaporization cylinder 11.

When the temperature of the vaporization tube 11 rises to the temperature at which the liquid fuel film boils due to energization, the motor 7 starts and the cone 8. Shaking board 9. The stirring blade 10 rotates.

When the turbo fan 13 generates wind pressure, secondary and secondary combustion air flows inside and outside of the carburetor cylinder 5 .

Simultaneously with the start of air blowing, the fuel pump operates, liquid fuel is supplied onto the cone 8 through the supply pipe 17, and the swinging plate 9. After passing through the stirring blade 1o, the oil becomes an oil layer with a particle size of 100 μm and scatters toward the vaporizing surface 18.

On the other hand, since primary air is sent into the vaporization cylinder 5, it is mixed with this vaporized fuel to form a mixed gas flow, which passes through the burner head 15 and becomes a combustion flame 16.

Inner diameter 8477 [L (7) Total acid value 0.1 change 11 in the vaporizer cylinder
If the amount of tar deposited on the vaporizing surface 18 is measured by the molding method, the curved line in Figure 4 is obtained. The results shown in were obtained. At this time, the temperature of the vaporizer cylinder 11 is 3
The temperature was 26°C.

In the same figure, curves B and C are conventional examples, B is smooth aluminum with a machined vaporization surface and a surface roughness of 10μ or less, the vaporization surface temperature is 275°C, which is the nucleate boiling temperature, and B is the same vaporization surface. The vaporization surface temperature is 325°, which is the rising temperature of the film ff1t.
It is C.

School principle 11: Raise the vaporizing surface temperature from the same figure! It can be seen that the amount of tar is reduced by reducing the temperature to the film boiling temperature and simultaneously roughening and anodizing the vaporization surface.

Next, metallic titanium was applied to the vaporization surface of an iron vaporization cylinder having the same shape and dimensions as those used in the above example by thermal spraying, and the surface was roughened to a roughness of 50 μm and anodized in nitric acid. A film was formed.

When continuous combustion was performed in this carburetor cylinder under the same conditions as in the above example and the amount of tar accumulated on the vaporization surface was measured, the results shown in the curved line in FIG. 4 were obtained, and the amount of tar was reduced compared to the conventional example.

Effects of the Invention In the liquid fuel combustion device of the present invention, the temperature of the vaporization surface is set to 1" - above the film boiling temperature, and the vaporization surface is roughened and anodized to facilitate the evaporation of oil droplets, and the unit area The effect of reducing tar accumulation is obtained because the amount of tar accumulated around the area is reduced and the tar is more easily decomposed.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional example, Fig. 2 is a configuration diagram of the vaporization surface section of a liquid fuel Y1 combustion device according to an embodiment of the present invention, and Fig. 3 is a configuration diagram of the same liquid fuel combustion device. FIG. 4 is a characteristic diagram illustrating the effects of the liquid fuel combustion device. 11... Vaporizing tube, 18... Vaporizing surface. Fig. 1 Fig. 2 Fig. 3 Fig. 4 Kyoto; Nupu temp. 8F'+<ttr Noah 3

Claims (6)

[Claims] (1) The liquid fuel 1 has a structure in which the vaporization surface is roughened and anodized, and the vaporization surface is heated to a temperature higher than the film boiling temperature of the liquid fuel 1 to vaporize the liquid fuel! '1 Burning neck. (2) The liquid fuel combustion device according to claim 1, wherein the vaporization surface temperature is 3000C or higher. (3) The liquid fuel 1 combustion device according to claim 1, wherein the roughness of the vaporizing surface is 50 to 500 μm. (4) The liquid fuel combustion device according to claim 1, wherein the vaporizing surface made of an anodizable metal is roughened and anodized. (5) The liquid fuel combustion device according to claim 1, wherein an anodizable metal is deposited by thermal spraying on the vaporization surface of the vaporization cylinder made of a non-anodizable metal, and the surface is roughened and anodized. (6) The liquid fuel shield according to any one of claims 2 to 5, wherein the anodizable metal is selected from the group of aluminum, titanium, and tantalum.