JPS58123008A - Combustion wick - Google Patents

Abstract

PURPOSE:To permit stable combustion of fuel for a long period of time as well as suppress the formation and accumulation of tarry substances by a method in which metal oxides are adsorbed on part of a fuel vaporizing portion consisting of a porous material, e.g., ceramic fibers, etc., and the grain size of the oxides is made smaller than the pore diameter of the fuel vaporizing portion. CONSTITUTION:A main wick 1 is made of a mixture of a ceramic fiber of a silica-alumina system, for example, and a polyacrylate, and an upper suction wick portion 2 connected to the lower part of the main wick 1 is made of a woven cloth of glass fibers, etc. Also, a lower suction wick portion 3 is made of a woven cloth of cotton, etc. In this case, metal oxides 5, together with anhydrous silicic acid, are dispersed and adsorbed in the fuel vaporizing portion 4 formed at the upper part of the main wick 1, and the grain size of the metal oxides 5 is made smaller than the main pore dieameter of the fuel vaporizing portion 4, whereby permitting the metal oxides 5 to be dispersed and adsorbed easily in the fuel vaporizing portion 4 and the capillary diameter of the fuel vaporizing portion 4 to be made smaller. Thus, fuel can be effectively sucked up to the surface of the fuel vaporizing portion 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion wick used in a liquid fuel combustor.

This is a so-called suction vaporization type combustor that sucks up liquid fuel by the capillary action of the combustion wick and vaporizes and burns the liquid fuel from the surface of the fuel vaporization section, which is the tip of the wick exposed in the vaporization chamber. is widely used in oil stoves, oil stoves, etc. In this type of combustor, the fuel vaporization section is exposed to a high temperature and oxygen-containing atmosphere, so during combustion, part of the fuel contained in the fuel vaporization section becomes tar-like due to oxidation and polymerization reactions. Therefore, the phenomenon of accumulation in the fuel vaporization part easily occurred. Especially when trace amounts of high-boiling components are mixed into the fuel (for example, when machine oil, light oil, salad oil, etc. are mixed into kerosene)
, or some of the fuel components have changed in quality (for example, oxides that occur when kerosene is stored at high temperatures or under direct sunlight for a long period of time,
(peroxide, resin, etc.), the generation and accumulation of the tar-like substance increases significantly.

When this tar-like substance accumulates in the fuel vaporization section, the capillary tubes on the surface or inside the fuel vaporization section are blocked, thereby inhibiting fuel suction and vaporization. As a result, the amount of fuel vaporized is abnormally reduced, causing problems such as the air-fuel ratio in the combustion chamber being disrupted and the generation of odor, soot, and toxic carbon monoxide. Furthermore, at the time of ignition, the tar-like substance prevents a rapid temperature rise in the fuel vaporization section and an increase in the amount of fuel vaporization, and it takes an extremely long time to reach stable combustion. This increased the generation of carbon oxide, etc. Furthermore, the tar-like substance causes the combustion wick and the metal parts that support it to stick together, making it impossible for the combustion wick to operate mechanically.
There were also dangerous conditions that made it impossible to extinguish the fire by lowering the wick.

The present invention aims to suppress the generation and accumulation of tar-like substances in order to eliminate such conventional drawbacks.

In order to achieve this object, the present invention impregnates, adsorbs, or coats a metal oxide on at least a portion of a fuel vaporization section made of a porous body mainly formed of ceramic fibers, and The particle size is smaller than the main pore size of the fuel vaporization section.

With this configuration, the capillary diameter of the fuel vaporization section is reduced, and high boiling point components and degraded components, which are the main causes of generation and accumulation of tar-like substances, are pushed out to the surface of the fuel vaporization section, which is in a high temperature state, due to capillary action. On the surface of this vaporizing part, it is affected by temperature and flame as well as being subject to the strong catalytic action of metal oxides, making it easy to decompose and vaporize. This suppresses the generation and accumulation of tar-like substances in the fuel vaporization section of the combustion wick, making it possible to maintain stable combustion for a long period of time.

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

FIG. 1 shows a longitudinal section of a combustion wick according to an embodiment of the present invention, and 1 mainly shows silica-alumina ceramic fibers (60=60 weight ratio in silica:alumina) with polyacrylic acid ester. It was formed by adding. 2 is the upper part of the suction wick connected to the lower part of the master 1, and is made of a braided cloth of glass fiber, cotton, or the like. 3 is the upper part of the wick, cotton, sufu,
Alternatively, it is made of braided cloth such as polypropylene. 4 is the fuel vaporization part formed on the top of main part 1. When installed in the combustor,
This is the part exposed to the combustion chamber. In the fuel vaporization section 4, metal oxide 5 is dispersed together with silicic anhydride.

It is adsorbed. 6 is a sewing thread, and t is an adhesive tape.

In the above configuration, the liquid fuel is sucked up from the suction wick upper part 3 through the suction wick upper part 2 to the main body 1, and is vaporized from the surface of the fuel vaporizing part 4. Here, the effects of this embodiment will be explained in detail by comparing the fuel flow and the differences between the conventional example and the main particle size of the metal oxide 6.

Figure 2 shows an example of a conventional combustion wick in which silicic acid anhydride is dispersed and adsorbed in the fuel vaporization part 4 of a porous body formed by adding polyacrylic acid ester to heptaramic fibers, and a cross section of the fuel vaporization part 4. Show the diagram. In addition, in a fuel vaporization section 4 of a porous body formed by adding polyacrylic acid ester to ceramic fibers, metal oxide 5 is dispersed and adsorbed together with silicic anhydride, and FIG. 3 shows the main particles of metal oxide 6. The diameter is equal to or larger than the main pore diameter of the fuel vaporization section 4. FIG. Although it is made small, it is a sectional view of the fuel vaporization part 4 of each combustion wick.

That is, the fuel F (solid arrow) is sucked up inside the main body 1 and vaporized from the surface of the fuel vaporization section 4. At this time, in the conventional example, as shown in FIG. 2, during steady combustion, the fuel vaporization section 4
Since the temperature of the fuel vaporizer 4 increases (to around 160° C.), the fuel is not drawn up to the surface of the fuel vaporizer 4 due to capillary action. Therefore, the fuel is easily vaporized from inside the fuel vaporization section 4, and high boiling point components and deterioration components (white arrows), which are the main factors for the generation and accumulation of tar-like substances, are not sucked up to the surface of the fuel vaporization section 4. It accumulated inside the fuel vaporization section 4, changed into a tar-like substance, and accumulated. Further, as shown in FIG. 3, when the main particle diameter of the metal oxide 6 is made equal to or larger than the main pore diameter of the fuel vaporization section 4, most of the metal oxide 5 is It is difficult to disperse and adsorb it inside the fuel vaporizing section 4, and therefore more of it adheres to the surface of the fuel vaporizing section 4. Therefore, the vaporization of the fuel F is suppressed, and the metal oxide 6 also peels off from the fuel vaporization section 4, and the surface area of the metal oxide 6 is also relatively small, so its effectiveness as a catalyst is reduced. The effect of inhibiting tar-like substance production and accumulation was small. However, as shown in FIG. 4, when the main particle diameter of the metal oxide 6 is made smaller than the main pore diameter of the fuel vaporization section 4, the metal oxide 6t is dispersed inside the fuel vaporization section 4, It is easy to adsorb the fuel, and therefore the capillary diameter of the fuel vaporization section 4 becomes small. Therefore, even during steady combustion, the fuel F is sucked up to the surface of the fuel vaporizer 4 by capillary action,
Along with this, high boiling point components and degraded components are also drawn up and pushed out to the surface of the fuel vaporization section 4.

As a result, high boiling point components and degraded components are removed from metal oxides 6 (because of their small particle size), which have a catalytic effect such as oxidation, on the surface where the temperature is higher than the inside of the vaporizer (around 180°C during combustion). The surface area is large and the catalytic effect is sufficient.

(However, the decomposition and vaporization of high-boiling components and altered components are promoted to some extent even inside the vaporization section.) As described above, the combustion wick of the present invention has a fuel vaporization section that is made of a porous body mainly made of ceramic fibers. At least a portion of the metal oxide is impregnated and adsorbed.

The main particle size of the metal oxide is made smaller than the main pore size of the fuel vaporizer, thereby suppressing the generation and accumulation of tar-like substances and providing stable combustion over a long period of time. This is something that can have a great effect.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a combustion wick according to an embodiment of the present invention, and FIGS. 2, 3, and 4 are explanatory views of the operation of the combustion wick. 1... Main window, 4... Fuel vaporization section, 6...
...Metal oxide. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A metal oxide is impregnated, adsorbed, or coated on at least a part of the fuel vaporization section made of a porous body formed mainly of ceramic fibers, and the main particle size of the metal oxide is determined by the main particle size of the fuel vaporization section. The combustion wick is smaller than the pore diameter.