JPS6029504A - Liquid fuel combustion apparatus of evaporation type - Google Patents

Abstract

PURPOSE:To shorten the time of evaporation and to decrease the depositing quantity of tar, by keeping the temperature in an evaporating surface at the temperature to boil a coating layer, by roughening the inside surface of a metallic evaporating cylinder, and by coating both surfaces with a layer to decompose organic substance made of material having high thermal conductivity and high heat radiant property, in the title combustion apparatus. CONSTITUTION:The inside surface of a metallic evaporating cylinder 1 is roughened and a layer 10 to decompose organic substance is coated on the roughly- treated surface. The layer is composed of a material 11 (shown by X) having high thermal conductivity and high heat radiant property, a catalyst 12 (shown by O) to decompose organic substance, and a refractory bonding material 13 (shown by shaded part), so that the evaporating surface can be kept at the temperature to boil the layer 10. With such an arrangement, liquid fuel containing unvolatile content 14 (shown by ) which causes formation of tar, is evaporated. By shortening the residence time of fuel on the layer, the quantity of tar deposited on the layer can be decreased.

Description

[Detailed Description of the Invention] a. --- Industrial Field of Use The present invention relates to a vaporized liquid fuel combustion device that is widely used in heaters, cookers, etc. In particular, there is a problem when tar accumulates. This is related to the vaporization surface.

Conventional structure and problems The vaporizing surface of conventional devices is made of die-cast aluminum or machined to maintain a smooth surface in the nucleate boiling temperature range, making it easy for tar to accumulate.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a vaporized liquid fuel combustion device which solves all of the above problems and has a vaporizing surface with less tar accumulation.

Structure of the Invention In order to achieve this object, the present invention roughens the inner surface of the metal vaporization cylinder, and the treated surface has an organic substance made of a material with high thermal conductivity and high flux resistance, an organic substance decomposition catalyst, and a heat-resistant binder. It is coated with a decomposition film to maintain the vaporizing surface temperature at the film boiling temperature. This configuration expands the vaporization area, prevents liquid fuel particles from becoming coarse due to recombination, shortens vaporization time by improving the atomizer, and extremely reduces tar accumulation due to catalytic action.

Description of examples Hereinafter, a practical example of the present invention will be explained using all the drawings.

First, a conventional example will be explained with reference to FIGS. 1a and 1b.

The vaporizing surface of the metal vaporizing tube 1 having a smooth inner surface is coated with a film 2 having low thermal conductivity, and the liquid fuel 3 is ejected together with air 4, vaporized by the film 2 on the heated vaporizing surface, and then transferred to the mixed gas tray burner head 5. It burns to form a flame 6. 7 is an electric heater for heating the vaporization cylinder; 8 is a temperature detection element; while the vaporization surface temperature is detected by the temperature detection element 8, the electric heater 7
The temperature is maintained at a constant temperature by conductive heat from the burner head 5. Such a conventional device has a drawback that tar is concentrated and accumulated at the location shown in 9.

Next, an example of the present invention will be described.

An embodiment of the present invention is shown in FIG. 2a + b. The material, shape, and combustion method of the vaporizer cylinder are the same as the conventional example shown in Figure 1, but the vaporization surface is treated to have a roughened surface of 5-2" to be rougher than the particle size of the liquid fuel, and organic matter decomposition is carried out on the same treated surface. The organic matter decomposition film 10 is coated with a film 10.The temperature of the vaporized surface is detected by the temperature detection element 8, and the temperature is maintained at film boiling temperature by the conduction heat from the electric heater 7 and the burner head 5. One of the main components is a fine powder material with high thermal conductivity and high flux, including carbon, graphite, beryllium oxide,
It is necessary to contain 15 to 50% by weight of at least one selected from the group of magnesium oxide, silicon carbide, vanadium carbide, tungsten carbide, titanium carbide, boron nitride, and zirconium polide. The second main component is an organic decomposition catalyst, which includes titanium, zirconium, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, copper,
and at least one selected from the group of rare earth oxides, elemental platinum and palladium, activated clay, zeolite, calcium silicate, alumina cement, and potassium carbonate. It is. Furthermore, the third main component is a heat-resistant binder, which must contain 40 to 80% by weight of a material selected from the group of water-soluble phosphates, water-soluble guates, and silicone paints.

FIG. 3 shows an enlarged view of the vaporized surface of the present invention. Metal vaporizer cylinder 1
The inner surface is roughened and an organic decomposition film 1 is applied to the treated surface.
0 fully coated. The film consists of a highly thermally conductive and highly resistant material 11 (indicated by an x), an organic matter decomposition catalyst 12 (
(indicated by O) and a heat-resistant bonding material 13 (indicated by diagonal lines). This type of vaporization surface metal device maintains the temperature of the vaporization surface within the boiling range and eliminates the non-volatile components 14 that cause tar.
When the liquid fuel 1 containing (indicated by △) is vaporized, the volatile components in the fuel are extremely short-lived due to the thermal effects of heat transfer and radiation because the material 11 with high thermal conductivity and high flux is present in the film. It vaporizes over time, shortening the residence time on the film and reducing the amount of tar.

Organic matter decomposition catalysts reduce tar formation through oxidative decomposition, partial oxidative decomposition, or cranking of nonvolatile components that cause tar. The heat-resistant bonding material is a material that has high thermal conductivity and high flux and is necessary for adhering to the organic substance heptad decomposition catalyst total vaporization cylinder.

The main materials for this are water-soluble phosphate, water-soluble silicate, and silicone paints, but in order to achieve complete curing and shorten curing time, all hardening materials are used, and they are fire-resistant, oil-resistant, and water-resistant. All fillers are used in order to ensure all reflective properties such as gender. The heat-resistant bonding material is required in an amount of 40 to 90% by weight in order to ensure adhesion to the vaporization tube and full film strength.

A specific example will be explained below.

Without further ado, a conventional example will be explained. The vaporizer cylinder having the structure shown in FIG. 1 was manufactured entirely from aluminum. Plate thickness 3mm, inner diameter 4
Q mm, height 3 Q mm vaporizing cylinder, film 2 on the vaporizing surface.
A skin of approximately 30/1 thickness was formed on smooth aluminum machined to a surface roughness of 10 μm or less, consisting of ferrite as a filler and silicone paint as a binder. This film has a thermal conductivity of 0.80 and a thermal conductivity of 0.8' at 200℃! i/mh'C. In this device, the temperature of the vaporization surface is set to 350'C by the heater and combustion heat, and the non-volatile components that cause tar are 37.5 T).
l) All 2.8I of bad kerosene including m! It/) (r % Air amount 5.3 N m'/Hr) Spray vaporizes at a rate of 5.3 N m'/Hr, and measures all changes over time in the amount of accumulated tar while burning.
The characteristic line A shown in the figure was obtained. Approximately 300 in 1000 hours
'Q's cool is accumulated at the place 9 in Figure 1, and 1500
At 0 hours, tar of 1y- or more is expected to accumulate locally, and when igniting and extinguishing, the amount of odor, hydrocarbons, and carbon oxides emitted increases, which is not desirable as a combustion device. Since this conventional coating has low thermal conductivity, kerosene vaporizes by nucleate boiling near the collision surface, causing tar to accumulate there.

Next, an example of the present invention will be described.

(1) The entire inner surface of the vaporizer cylinder, similar to the above conventional example, is roughened to a surface roughness of approximately 700μ as shown in Figure 3, and the coating composition after combustion is 45% by weight of graphite and 10% by weight of manganese dioxide.
Approximately 30μ thick, made of 45% by weight heat-resistant binder.
The organic matter decomposition film was completely formed. The heat-resistant bonding material in this example is composed of primary aluminum phosphate as a main material, sodium phosphate as a hardening material, and alumina as a filler. The thermal conductivity of this film at 200°C is 0.90 and the thermal conductivity is approximately 15-7m h.
'C. When the temperature of the vaporization surface was set to 1350'c and the change in the amount of accumulated tar over time was measured under the same conditions as in the conventional example, characteristic line 1 shown in FIG. 4 was obtained. Approximately 3.00 hours in 1000 hours.
It is expected that 5 mg of tar will accumulate and the amount will be extremely small at about 5 ml even after 15,000 hours. The particle size of the sprayed kerosene in this example was about 1 mm, and the particle size after colliding with the vaporizing surface was about 0.2 to 0.5 m.

(2) After firing, the inner surface of the vaporizer cylinder was roughened in the same manner as in Example 1 above, and the film composition after firing was 20% by weight of aluminum oxide, and 20% by weight of alumina cement as an organic matter decomposition catalyst.
An organic decomposition film of approximately 30 μm in thickness consisting of 70% by weight of a heat-resistant binder was completely formed.

The heat-resistant binder in this example is composed of sodium silicate as the main material and silica as the filler. The thermal conductivity of this film at 200° C. is 0.82 and the thermal conductivity is approximately 101 d/mh'C. Evaporation surface temperature 3
When the change in accumulated tar amount over time was measured at 50 DEG C. under the same conditions as in the conventional example on page 10, characteristic line 2 shown in FIG. 4 was obtained. Approximately 1 in 1000 hours.
0''g of tar accumulated on the bottom of the vaporization chamber.

(3) The same vaporizing cylinder as in Example 1 above is coated with 23% by weight of graphite, 76.2% by weight of a heat-resistant binder, and 0.2% by weight of platinum as an organic matter decomposition catalyst after firing. A 30μ thick organic matter decomposition film was formed. The heat-resistant bonding material in this example is composed of primary aluminum phosphate as a main material, sodium phosphate as a hardening material, and alumina as a filler. The thermal conductivity of this film at 200'C is 0.81, and the thermal conductivity is approximately 7 g/m-h.
It is °C. When the vaporization surface temperature was set at 350° C. and the change in accumulated tar amount over time was measured under the same conditions as in the conventional example, a characteristic curve 3 shown in FIG. 4 was obtained.

Approximately 11 mg of tar accumulated on the bottom of the vaporization chamber in 1000 hours.

2) On the same vaporizing cylinder as in Example 1 above, an organic matter decomposition film with a thickness of about 30μ consisting of 23% by weight of graphite, 10% by weight of manganese dioxide, 11% by weight of manganese dioxide, and 67% by weight of a heat-resistant binder was applied. was formed. The heat-resistant bonding material in this example is composed of aluminum phosphate as a main material, sodium phosphate as a hardening material, and alumina as a filler.

The thermal conductivity of this film at 200° C. is 0.83 and the thermal conductivity is approximately 6 μm/mh'c. When the change in the amount of accumulated tar over time was measured under the same conditions as in the conventional example, a characteristic line 4 shown in FIG. 4 was obtained. Approximately 32 m7 of tar accumulated on the bottom of the vaporization chamber in 1000 hours (51) In the same vaporization cylinder as in Example 1 above, the composition of Bl after firing was 23% by weight of graphite, zeolite [Ca(Na).

K) 4A116S13oO72] 8% by weight, activated clay [
Al 2S113029] 2% by weight, heat-resistant binder 67
An organic matter decomposition film having a thickness of about 30 μm was formed. The heat-resistant bonding material in this example is composed of primary aluminum phosphate as the main material, sodium phosphate as the hardening material, and alumina as the filler. The thermal conductivity of this film at 2000C is 0.83 and the thermal conductivity is approximately 6vmh'C. When the change in accumulated tar amount over time was measured under the same conditions as in the conventional example, a characteristic line 5 shown in FIG. 4 was obtained. Approximately som'i of tar accumulated on the bottom of the vaporization chamber in 1000 hours.

(6) Complete formation of an organic decomposition film with a thickness of about 30 μm on the same vaporizing cylinder as in Example 1 above, which has a film composition after firing of 20% by weight of boronated zircon, 13% by weight of manganese dioxide, and 67% by weight of heat-resistant binder. did. The heat-resistant bonding material in this example is composed of silicone resin as the main material and ferrite as the filler. This film has a thermal conductivity of 0.81 and a thermal conductivity of about 6-/mh°C at 200°C. When all changes over time in the amount of accumulated tar were measured under the same conditions as in the conventional example, a characteristic line 6 shown in FIG. 4 was obtained. Approximately 100"iF of tar accumulated on the bottom of the vaporization chamber in 1000 hours.

(7) The same vaporizing cylinder as in Example 1 above has a film composition of 20% by weight of silicon carbide and 10% by weight of calcium silicate.
, an organic decomposition film consisting of 70% by weight of a heat-resistant binder was completely formed. 13,,,- in this example.

The heat-resistant binder is mainly composed of sodium silicate and has a silica filler. The thermal conductivity of this film at 200°C is 0.80%, approximately 4 kA/m.
h'C. When the change in accumulated tar amount over time was measured under the same conditions as in the conventional example, a characteristic line 7 shown in FIG. 4 was obtained. Approximately 1201 ng of tar accumulated on the bottom of the vaporization chamber in 1000 hours.

Effects of the Invention As described above, according to the present invention, the inner surface of the metal vaporization cylinder is roughened, and the treated surface is coated with a material having high thermal conductivity and high radiation property.
By covering with an organic decomposition film made of an organic decomposition catalyst and a heat-resistant binder and maintaining the vaporizing surface temperature at the film boiling temperature, a vaporizing liquid fuel combustion device with extremely low tar accumulation can be obtained.

[Brief explanation of drawings]

Figures 1a and 1b show an example of a conventional vaporized liquid fuel combustion device.
Cross-sectional view and top view showing an example package, FIG. 2a. b is a sectional view and a top view showing an embodiment of the vaporized liquid fuel combustion device of the present invention, FIG. 3 is a partially enlarged sectional view of the vaporizing surface of the same device, and FIG. It is a characteristic diagram showing the relationship between the amount of accumulated tar and the amount of accumulated tar. 1...Metal vaporization tube, 7...Electric heater, 8.Old temperature detection element, 1o...Organic substance decomposition film. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2 Figure 3 Figure 4 Burning time (Hr)

Claims (1)

[Scope of Claims] (1) The inner surface of the metal vaporization cylinder is subjected to surface roughening treatment, and the treated surface is coated with an organic matter decomposition film made of a highly thermally conductive and highly fused material, an organic matter decomposition catalyst, and a heat-resistant binder. A vaporizing liquid fuel combustion device configured to maintain the vaporizing surface temperature at the film boiling temperature. (2) The vaporized liquid fuel combustion device according to claim 1, wherein the surface roughness is equal to or larger than the particle size of the liquid fuel. (3) The organic matter decomposition film consists of 15 to 50% by weight of a material with high thermal conductivity and high flux resistance, 0.1 to 15% by weight of an organic matter decomposition catalyst, and 40 to 80% by weight of a heat-resistant binder. The vaporized liquid fuel combustion device described in Section 4.G4) High thermal conductivity and high flux resistance materials include carbon, graphite, beryllium oxide, magnesium oxide, carbonized carbide, vanadium carbide, tungsten carbide,
The vaporized liquid fuel combustion device according to claim 3, which contains at least one member selected from the group consisting of titanium carbide, poron nitride, and 2-zirconium polide. (5) As organic substance decomposition catalysts, titanium, zirconium, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, copper, and rare earth oxides, elemental platinum and palladium, activated clay, zeolite, calcium silicate 4. The vaporized liquid fuel combustion device according to claim 3, which comprises one or more selected from the group consisting of , alumina cement, and potassium carbonate. (6) #The vaporized liquid fuel combustion device according to claim 3, wherein the thermal binder is selected from the group of water-soluble phosphate paints, water-soluble silicate paints, and silicone paints. (7) The vaporizing liquid fuel combustion device according to claim 1, wherein the vaporizing surface temperature is maintained at the film boiling temperature using combustion heat, an electric heater, and a temperature detection element.