JPH09324903A - Evaporating element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide stable vaporization even in the use of a liquid fuel of poor refining and a fuel akin to heavy oils to make it hard for a nozzle to be plugged and to extend a service life, by using as an evaporating element a porous body of three-dimensional mesh construction having inner communication spaces. SOLUTION: A liquid fuel stored in a tank 11 is fed to a vaporizer 12 via a fuel supply pipe 14 by means of a pump 13 to be vaporized in the vaporizer 12 by means of a heater 16 to be supplied to a burner 18 through a nozzle 17. An evaporating element 15 in the vaporizer 12 comprises a porous body of three-dimensional reticulate construction having inner communication spaces, and the heater 16 is energized to heat the vaporizer 12 to raise the evaporating element 15 in temperature. The porous body is formed of a ceramic having a bulk density of 0.5 to 2.5, a number of holes of 13 to 50per 2.5cm, and a ratio of hole of 85 to 50%. Therefore, it is possible to provide stable vaporization even in the use of a liquid fuel of poor refining and a fuel akin to heavy oils to make it hard for the nozzle to be plugged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vaporization element used in a passage in a vaporization device such as a heating device or a water heater which gasifies a liquid fuel and uses it as a fuel source.

[0002]

2. Description of the Related Art A conventional vaporizer has a structure as shown in FIG. That is, a tank 11 for storing liquid, a vaporizer 12 for vaporizing liquid fuel, and a pump 1 for sending liquid fuel.
3, the fuel supply pipe 14 for sending the liquid fuel to the vaporizer, and the fuel is vaporized by the heater 16 in the vaporizer 15 and supplied to the burner 18 from the nozzle 17.

Here, a sintered metal or a ceramic porous member is used as a member used for the vaporization element. In such a configuration, the heater 16 is energized to heat the vaporizer and raise the temperature of the vaporization element. Preheating is completed when the temperature inside the vaporizer rises to a temperature sufficient to vaporize the liquid fuel, liquid fuel flows into the vaporizer from the fuel supply pipe, vaporizes in the vaporizer, and is sent to the burner from the nozzle and ignited. To burn.

[0004]

However, when the vaporization element used in the vaporizer described above uses liquid fuel with poor purification or aged liquid fuel, foreign substances such as soot and tar are easily generated in the vaporization process. However, there is a problem that the foreign matter adheres in the vaporization element to cause clogging, and the fuel supply function deteriorates in a short period of time. Since the liberalization of oil imports in 1996, poorly refined fuels have been circulating in Japan. In such a fuel, foreign matters are likely to be generated, and in the conventional vaporization element, clogging occurs at an early stage.

In order to solve this, it has been attempted to increase the porosity and porosity of the vaporization element. However, in the case of a ceramic porous body, mechanical strength is increased when the porosity and porosity are increased due to press molding. Was markedly reduced to a practical level. Therefore, in order to remove the soot and tar deposited on the vaporization element after use for a certain period of time, backwashing and incineration treatment were absolutely necessary.

On the other hand, the sintered metal was developed for the purpose of shortening the vaporization preheating, but in the fuel of low purification degree, since sulfur is not sufficiently removed, it reacts with the water in the fuel to produce sulfuric acid. To do. This sulfuric acid may possibly damage the metal vaporization element. The present invention has been made in view of the above problems, and provides a vaporization element that is stable in vaporization even when using a liquid fuel or a fuel close to heavy oil that is poorly purified, and that is difficult to clog and can be ejected to a nozzle and has a long life. It is in.

[0007]

The vaporization element according to claim 1 of the present invention is a vaporization type combustion apparatus for vaporizing and ejecting liquid fuel by means of a fuel supply means and a heating means to burn it.
It is characterized in that a porous body having a three-dimensional network structure having an internal communication space is used as the vaporization element.

Further, in the vaporization element according to claim 2 of the present invention, the porous body is made of ceramic, and its bulk specific gravity is 0.5.
.About.2.5, the number of holes per 2.5 cm is 13 to 50, and the porosity is 85 to 50%.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described below.

The porous body having a ceramic three-dimensional network skeleton structure having an internal communication space is obtained by adhering the ceramic slurry around the skeleton of a polyurethane foam having a three-dimensional network skeleton structure made of synthetic resin, drying and firing. Oxide ceramics are used as the ceramic material of the ceramic porous body having the three-dimensional network skeleton structure, and the material is not particularly limited, and examples thereof include alumina, silica, mullite, cordierite, and zirconia. Further, clay minerals composed of complex oxides such as Kibushi clay, ordinary porcelain clay, frog clay and sirimite may be used.

In addition, a material having excellent thermal conductivity, such as silicon carbide or aluminum nitride, may be used to increase the rate of temperature rise. Further, a low melting point substance such as lithium amino silicate, an alkali metal oxide or an alkaline earth metal oxide, or a glass component may be used in order to improve the sintering density which is generally adopted for increasing the strength. Furthermore, compounds shared with the main ceramic powder, for example, oxides composed of boron, lead and copper can be mentioned.

The number of pores of the porous body having a three-dimensional network structure used in the present invention is preferably 13 to 50 per line of 2.5 cm, and more preferably 20 to 40. If the number of holes is 13 or less, uneven vaporization of the fuel occurs, and stable vaporization is difficult to obtain. Further, when the number is 50 or more, the skeleton forming the three-dimensional network structure becomes thin, and it is difficult to obtain mechanical strength. The porosity is preferably 85 to 50%, more preferably 70 to 60%. When the porosity is 85% or more, vaporization is insufficient and uneven, and tar and soot generated in the vaporization process may be supplied to the burner without being filtered. If it is 50% or less, clogging tends to occur early and vaporized fuel is difficult to be supplied to the burner section. The porosity is expressed by the following equation. Porosity = {(true density-bulk specific gravity) / true density} × 100 Further, the vaporization element shape of the ceramic porous body having the three-dimensional net-like skeleton structure of the present invention may be cylindrical or cylindrical as well as cylindrical. It doesn't matter.

[0013]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following examples.

[Embodiment] The vaporization element of the embodiment has 30 holes.
Alumina / Petalite (lithium aluminosilicate) /
A slurry of composite powder composed of normal porcelain earth was adhered, dried and fired to obtain a cylindrical vaporization element having a bulk specific gravity of 0.7 and a porosity of 74%. The size was 12 mmφ × 70 mm.

[Comparative Example] As the vaporizing element of the comparative example, a press-molded element of alumina particles which is currently in use ("Alundum" manufactured by Narita Seisakusho Co., Ltd.) was used.

The vaporizing elements of the above-mentioned Examples and Comparative Examples are
Using the vaporization type combustion apparatus shown in FIG. 1, continuous combustion was performed using FRK test kerosene under the condition that the combustion heat quantity was 4300 Kcal / h. The test results of both are shown in Table 1.

[0017]

[Table 1]

[0018]

According to the present invention, as can be seen from the above-mentioned embodiment, the porosity is larger than that in the prior art and clogging is less likely to occur.
Further, even if the porosity is large, the three-dimensional reticulated skeleton provides uniform vaporization with stable pores, which is a long-life vaporization element.

[Brief description of drawings]

FIG. 1 is an example of a configuration diagram of a vaporizer.

FIG. 2 is an enlarged view of a part of the structural diagram of the vaporization element of the present invention.

[Explanation of symbols]

 1 Ceramic Porous Body 2 Skeleton 3 Voids 11 Fuel Tank 12 Vaporizer 13 Fuel Supply Pump 14 Fuel Supply Pipe 15 Vaporization Element 16 Heater 17 Nozzle 18 Burner

Claims (2)

[Claims] 1. A vaporization-type combustion apparatus for vaporizing, ejecting and burning liquid fuel using a fuel supply means and a heating means, wherein a porous body having a three-dimensional net structure having an internal communication space is used as a vaporization element. Characterizing vaporization element. 2. The porous body is made of ceramics, has a bulk specific gravity of 0.5 to 2.5, has 13 to 50 pores per 2.5 cm, and has a porosity of 85 to 50. %. The vaporization element according to claim 1, wherein the vaporization element is%.