JPS6331682B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a combustion wick used in a liquid fuel combustor, and its purpose is to suppress the generation and accumulation of tar-like substances in the fuel vaporization part of the combustion wick and maintain stable combustion over a long period of time. The purpose is to provide a combustion wick that can be obtained. BACKGROUND ART A so-called suction vaporization type combustor, which sucks up liquid fuel by the capillary action of a combustion wick, vaporizes the liquid fuel from the surface of a fuel vaporization part, and burns it, is widely used in oil stoves, oil stoves, and the like. In this type of combustor, the fuel vaporization section is exposed to a high temperature and oxygen-containing atmosphere, so some of the fuel contained in the fuel vaporization section undergoes oxidation, polymerization, etc. during combustion. This turns into a tar-like substance that accumulates in the fuel vaporization section. 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, if some of the fuel components have changed in quality (for example, if kerosene is stored at high temperatures or under direct sunlight for a long period of time, oxides, peroxides, resins, etc. are formed). , the amount of 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 vaporizing section are blocked, inhibiting fuel suction and vaporization. As a result, the amount of fuel vaporized is abnormally reduced, the air-fuel ratio in the combustion chamber is disrupted, and a large amount of odor, soot, and harmful carbon monoxide are emitted. In addition, 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. Large amounts of odor, soot, and carbon monoxide were being generated. Furthermore, the tar-like substance caused the wick to stick to the metal part that supported it, making it impossible to mechanically operate the wick, and lowering the wick and making it impossible to extinguish the fire, which was dangerous. In order to eliminate these conventional drawbacks, the present invention
This invention suppresses the generation and accumulation of tar-like substances, and one embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, 1 is the main core, which is made by bonding silica-alumina ceramic fibers (silica:alumina≒50:50, weight ratio) with a silica-based binder. Reference numeral 2 denotes a suction core, which is made of polypropylene cloth and is connected to the main core 1. 3 is a fuel vaporization section, when installed in a combustor (not shown),
This is the part exposed to the combustion chamber. The upper surface of the fuel vaporization section 3 is covered with a covering material 4. This coating material 4 is made of an inorganic pigment, anhydrous silicic acid, and a water-soluble organic binder, and is applied to the surface of the fuel vaporization section 3 so as not to lose its porosity. 5 is sewing thread, 6
is adhesive tape. In the above configuration, liquid fuel is sucked up from the suction wick 2 to the main wick 1 and vaporized from the surface of the fuel vaporization section 3. Here, the flow of fuel will be explained in detail as shown in FIG. 2. That is, the fuel f is sucked up inside the main core 1 and vaporized from the surface of the fuel vaporization section 3. On the other hand, a portion of the fuel f changes into a tar-like substance t near the surface of the fuel vaporization section 3, particularly near the surface of the tip of the fuel vaporization section 3 which is exposed to high temperatures, under the influence of temperature and oxygen. In addition, impure components (altered components or high boiling point components such as salad oil) contained in kerosene are also pushed up to the top of the wick by the kerosene and accumulated there. This causes clogging and reduces the vaporization area, lowering the amount of heat generated. However, when the covering material 4 is provided as in this embodiment, the amount of vaporization in that portion decreases from the beginning, and as a result, the temperature on the surface and inside of the fuel vaporization section 3 becomes high. Therefore, even if there are high boiling point components in this area, these components will easily vaporize or decompose. Furthermore, since the inside of the fuel vaporization section 3 is not directly exposed to air, kerosene is less likely to be oxidized, and high molecular weight tar components due to so-called polycondensation are less likely to be formed. To explain these principles in more detail, the temperature of the fuel vaporization section 3 of a conventional combustion wick of the kerosene vaporization type that uses kerosene is limited by the components of the kerosene.
When commercially available JIS kerosene is used, the temperature of the fuel vaporizing section 3 (2-3 mm below the tip) is 160°C to 170°C. However, at this temperature, it is not possible to vaporize or decompose the very small amount of impurity components (high boiling point components) contained in kerosene, and as a result, these high boiling point components accumulate inside and become vaporized. The quantity is decreasing. Only then does the temperature of the fuel vaporization section 3 rise, but by this time the calorific value has already decreased, resulting in poor exhaust gas characteristics and strong odor. However, if the fuel vaporization section 3 is covered with the covering material 4 for the purpose of suppressing the vaporization of kerosene as in the embodiment of the present invention, the temperature will rise and reach a high temperature even if the calorific value does not decrease, so these components can be easily removed. Disassemble,
Tar components are less likely to accumulate. The coating material 4 may be made of any component as long as it has heat resistance (600 to 700 degrees Celsius), but the pigment particles should not be too fine or too large, and should not be used in the fuel vaporization section. 10μ to 100μ slightly finer than the average pore of 3.
Good condition. In addition, a binder is required when applying this coating material 4 to the fuel vaporization part 4, but this binder is heat resistant and has excellent adhesiveness to the fuel vaporization part 3.
It is also necessary to have sufficient heat resistance, not to penetrate into the interior of the fuel vaporization section 4, and not to damage the porosity of the covering material 4 to some extent. The present invention relates to the component ratio of these binders and pigments, and the effects thereof will be explained below using specific examples. We prepared the following types of lamp wicks. The basic configuration of the lamp wick is the configuration shown in FIG. 1, with only the main wick 1 being changed. [1] Main core 1 made of a glass/splash blend [2] Main core 1 made of a glass/splash blend, with a black pigment solid content of 100% containing FeO as the main component at the exposed tip part, colloidal silica solid content of 5%, polyvinyl alcohol ( Main core 1 with coating material 4 mixed at a ratio of 2 parts (product number PVA117) 4 mm from the top end. [3] The main core is formed from a silica-alumina ceramic core, and the fuel vaporization section 3 is an untreated main core. [4] The above-mentioned coating material 4 is applied to the main core 1 of [3] 3 mm from the top end. The above four types of main cores 1 were prepared. For acceleration experiments, kerosene mixed with 0.1% salad oil was used and continuously burned in a portable oil stove. The results are shown in Table 1.

[Table] As is clear from Table 1, in the main core 1 of [1] and [2], 3 to 4
Tar was formed at a distance of 5 to 10 mm from the tip of the main core 1 in about an hour, and as a result, the ability to absorb kerosene was insufficient and the amount of combustion deteriorated. In the case of the main core 1 of [3] and [4], the one of [3] without the covering material 4 is approximately
Calories were reduced by 20% in 10 hours, and tar had accumulated inside main core 1, slightly below the tip. The product [4] provided with the coating material 4 had a calorie reduction of 20% in 30 hours, and although tar was deposited on the surface near the tip of the main core 1, almost no tar was accumulated inside. Also, it takes about 80 hours to reduce calories by 30% compared to main core 1 of [3].
It lasted twice as long. Next, prepare the main core 1 of [3] above, and
Various main cores 1 were made with the formulations shown in the table, and the combustion characteristics are shown in Table 2. The main core 1 is made of an organic binder, has a thickness of 3 mm, and is flexible. This organic binder did not dissolve in water and was water repellent.

[Table] In Figure 2, A (represents the solid content ratio of inorganic pigment, silicic anhydride, and organic binder) B (represents the continuous combustion time with kerosene mixed with 0.1% salad oil, and the amount of combustion from the initial stage) When it is 80%, it is said to be 20% down, and when it is 70%, it is said to be 30% down.) C (A black pigment whose main components are FeO, _MnO2 ,
It is in a water suspension state. ) D (20% colloidal silica solution using Nissan Chemical Co., Ltd. Snotex C-20) E (Polyvinyl alcohol using Kuraray Co., Ltd. PVA117
It was used. ) As can be seen from [5] and [6] in Table 2, those in which the binder silicic anhydride is less than 2 to the inorganic pigment have poor binding properties, so other materials may be used until the combustion rate deteriorates by 20%. However, the coating material 4 peels off during combustion and the time for 30% deterioration is shorter, and when combustion is interrupted and reburned, , the performance was no different from that of the unprocessed version. Also

On the other hand, when the silicic anhydride is 10 or more compared to the pigment, as in main core 1 of [9], main core 1
Pigment and silicic anhydride as a binder permeate into the tip and the oil content near the tip decreases, so that the effect of providing the covering material 4 is almost lost. Further, as shown in main core 1 of [14], when the organic binder exceeds 5, the coating material 4 has no effect because it turns into a tar component during combustion. Also, as in main core 1 of [12], the initial properties were good when using only a pigment and an organic binder, but once the dry firing was carried out, the binding property was lost and it began to peel off. As is clear from the above explanation, in order to exhibit the effect of the coating material 4, an appropriate binder is required for the inorganic pigment, and the ratio is 2 to 10 parts of silicic anhydride to 10 parts of pigment, and 2 to 10 parts of organic pigment. It was appropriate for the binder to be 5 or less. In addition, there are other water glass-based silicic acid anhydrides, but they crack when heated and are not effective. A certain amount of organic binder has no effect on the deterioration of the combustion amount even if it is not present, but it is very effective from the viewpoint of stability of the coating material 4. However, if the amount of the organic binder is too large, the coating material 4 can be made stable, but the organic binder turns into tar during combustion, causing clogging and deteriorating the amount of combustion. As described above, according to the present invention, generation and accumulation of tar-like substances can be suppressed and stable combustion can be achieved over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a combustion wick according to an embodiment of the present invention, and FIG. 2 is an explanatory view of its operation. DESCRIPTION OF SYMBOLS 1... Main core, 2... Suction core, 3... Fuel vaporization part, 4... Covering material, 5... Sewing thread, 6... Adhesive tape.

Claims (1)

[Claims] 1. The fuel vaporization section is made of silica-alumina ceramic fiber, and at least a part of the surface of the fuel vaporization section is coated with a coating material composed of an inorganic pigment, anhydrous silicic acid, and an organic binder, and the blending ratio is inorganic. 2 to 10 parts of silicic anhydride and 5 parts of organic binder to 100 parts of pigment
A combustion wick characterized by: