JPS63210512A - Liquid fuel combustion device - Google Patents

Abstract

PURPOSE:To maintain the temperature of flame port section at high temperature even in a small amount of combustion to stabilize combustion, by a method wherein a flame port tube, having cylindrical configuration with a bottom, is connected to the upper part of an evaporating tube, provided with an upright heat receiving part having a built-in electric heater at the center thereof, while a gas passageway is provided at the lower part and in the outer periphery of the flame port tube. CONSTITUTION:When an electric heater 2 is switched on, a heat receiving part 3 is heated, an evaporating tube 1 is heated by heat conduction and, simultaneously, a flame port tube 4 is heated from the bottom. Fuel, discharged into an evaporating chamber 1a through a nozzle 10, contacts with the heat receiving part 3 and the wall surface of the evaporating tube 1 of a high temperature; it is evaporated, mixed with air, supplied through a throat 12, and injected into a combustion chamber 6 through flame ports 4b for ignition and forms combustion flame. Subsequently, the resulting gas is injected into the combustion chamber 6 through small holes 4a bored in the wall surface of the flame port tube 4, is ignited by flames formed at the flame ports 4b for ignition and combustion is started. The flames are formed from small holes 4a toward the inside of a combustion tube 9 and are concentrated to the central part of the tube 9, whereby the diameters of the flames become small and the flames ascend through the combustion tube 9. The flames heat the small holes 4a and combustion temperature is raised upon normal combustion, whereby stabilized combustion condition may be obtained upon small combustion.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a liquid fuel combustion device used in oil heaters and the like.

2. Description of the Related Art Conventionally, this type of combustion device has a vaporization chamber 1 made of aluminum alloy or the like with an electric heater 2 embedded in its outer periphery, as shown in FIG.
A flame hole plate 3 is connected to the upper part of the combustion chamber 1, and the fuel is pumped into the vaporization chamber 1 by a fuel pump 8, discharged from a fuel nozzle 7, and vaporized on the wall surface of the vaporization chamber 1 heated by the electric heater 2 and combustion heat. The fuel gas and the air supplied from the blower 6 through the throat 5 are premixed and then
A method of ejecting and burning the fuel is often used.

Problems to be Solved by the Invention According to such conventional means, in order to heat the vaporization chamber with combustion heat, it is necessary to direct the combustion flame outward or in a straight direction. Due to the large diameter, it is difficult to downsize the combustion device, there is a lot of heat dissipated from the flame hole, and the temperature at the flame hole is low, so the flame becomes unstable when the combustion amount is small, and the range of variable adjustment of the combustion amount is small, etc. It has the following problems.

Means for Solving the Problems In order to solve these problems, the present invention has a heat receiving section with a built-in electric heater installed in the vaporization chamber in the approximate center of the vaporization chamber. A bottomed cylindrical flame tube with an ignition flame hole drilled in it is connected so that the bottom surface is in contact with the heat receiving part of the vaporization tube, and a vaporized gas passage is provided from the vaporization chamber to the lower part and outer periphery of the flame hole tube. It has a similar structure.

Function In the above configuration, the fuel supplied to the vaporization chamber is vaporized in the heat receiving part heated by the electric heater and the inner surface of the vaporization tube, mixed with the primary air, and passed through the vaporized gas passage to the small hole of the flame tube and the ignition tube. The flame is ejected from the flame hole, forms a flame in the inner circumferential direction of the flame hole tube, and burns. Since the combustion flame is formed in the inner circumferential direction, the diameter of the flame becomes small, and the diameter of the combustion tube on the downstream side of the combustion chamber can be made small. In addition, since the flame is directed inward, there is less heat dissipated from the flame hole, and by being heated by the flame, the temperature of the flame hole can be maintained at a high temperature even when the amount of combustion is small, resulting in a stable combustion state. be able to.

On the other hand, at the time of ignition, if the temperature of the ignition part is low, the vaporized gas will be cooled and the energy required for ignition will be large, making ignition difficult and causing ignition delay.However, according to the configuration of the present invention, the electric heater The heat-receiving part of the vaporizing cylinder is heated, and the flame tube in contact with the heat-receiving part is heated, but because the flame hole for ignition is provided on the bottom of the flame-hole tube near the heat-receiving part and the vaporization chamber, the electric heater is not energized. The temperature of the post-ignition flame hole increases faster than other flame holes, and the vaporized gas reaches the post-ignition flame hole faster than other flame holes, making it easier to ignite. When an igniter is used to ignite an ignition flame hole, a flame is formed in the same flame hole, and the heat ignites other flame holes where the vaporized gas reaches with a slight delay, forming a flame over the entire flame hole group. Therefore, compared to a case without an ignition flame hole, it is possible to ignite in a short time after starting electricity, and since the flame hole drilled in the wall of the flame hole can be reliably ignited, raw gas (unburned gas) due to ignition delay The generation of vaporized gas) can be reduced.

Example An embodiment of the present invention will be described below based on the drawings.

Referring to ζ in FIG. 1, reference numeral 1 denotes a vaporizing cylinder made of aluminum alloy or the like, which has an internal space forming a vaporizing chamber 1a, and has a hollow cylindrical heat receiving part 3 with an electric heater 2 built therein in the center. 4 is a flame hole cylinder with a small hole 4a on the wall and a flame hole 4b for ignition on the bottom.
Further, the center part of the bottom surface is in contact with the heat receiving part 3. Reference numeral 5 denotes a vaporized gas passage which communicates from the vaporizing chamber 1a with the small hole 4a through the lower part of the flame port cylinder 4 and the outer circumference thereof. Reference numeral 6 indicates a combustion chamber formed in the space inside the flame tube, 7 indicates a secondary air passage for guiding air supplied from a blower to a secondary air outlet, and 8 supplies secondary air to the combustion chamber. It is a secondary air outlet for. 9 is a combustion tube provided on the downstream side of the combustion chamber 6; 10
The fuel nozzle discharges the fuel supplied from the fuel pump 11 into the vaporization chamber 1a. A throat 12 blows air supplied from a blower 13 into the vaporization chamber. 13 is a blower for supplying air necessary for combustion.

14 is an igniter for igniting the vaporized gas.

Reference numeral 15 denotes a temperature detector made of a thermocouple or the like for detecting the temperature of the vaporization cylinder 1, and is fixed to the bottom of the vaporization cylinder.

In the above configuration, when electricity is applied to the electric heater 2, the heat receiving part 3 is heated, and the vaporizing tube 1 is further heated by heat conduction, and at the same time, the flame hole tube 4 is heated from the bottom surface.

When the temperature of the vaporization tube reaches the fuel vaporization temperature or higher by a temperature detector 15 fixed to the bottom of the vaporization tube 1 and a control circuit (not shown), a high voltage is applied to the igniter 14 and the flame tube, and the igniter is activated. A spark is generated between the tip of No. 14 and the bottom of the burner tube. Next, the fuel pump 11 operates and the fuel tank (not shown)
The fuel is then discharged into the vaporization chamber 1a through the fuel nozzle 10. At the same time, the blower 13 also operates, and primary air is supplied into the vaporization chamber 1a through the throat 12, and air is supplied into the combustion chamber from the secondary air passage 7 through the secondary air outlet 8.
It is divided into two parts: air and air. The fuel discharged into the vaporization chamber 1a contacts the high-temperature heat receiving part 3 and the wall surface of the vaporization cylinder 1, vaporizes, mixes with the air supplied from the throat 12, passes through the vaporized gas passage 5, and enters the combustion chamber 6 through the ignition flame hole 4b. The fuel is ignited by the spark from the igniter 14, forming a combustion flame. Subsequently, the vaporized gas is ejected into the combustion chamber 6 through a small hole 4a formed in the wall surface of the flame hole cylinder 4, and is ignited by a flame formed in the ignition flame hole 4b to start combustion.

The flame is formed inward from the small hole 4a, heats the heat receiving part 3, and supplies a heat source for vaporization, and the flame is concentrated in the center and rises in the combustion tube 9 with a small diameter. During normal combustion, flames are formed from the small holes 4a in the inner circumferential direction, so the flames heat the small holes 4a and the combustion temperature rises, making it possible to obtain a stable combustion state even during low combustion. In addition, when there is no flame hole for ignition as in the present invention at the time of ignition, a small hole 4a bored in the wall surface of the flame hole cylinder 4 is used.
Although it is necessary to directly ignite the small hole 4a, the temperature rise is slow because the small hole 4a is far from the electric heater 2, which is the heat source. If an attempt is made to ignite the small hole 4 when the temperature is low, the vaporized gas of the fuel will be cooled, making ignition difficult, causing a delay in ignition, and causing generation of raw gas (unburned vaporized gas).

According to the structure of the present invention, by providing the ignition flame hole 4b on the bottom surface of the flame hole cylinder 4 near the electric heater 3 which is a heat source, the temperature of the ignition part increases quickly and ignition can be carried out in a bright state. 4b can be easily ignited. At this time, the larger the cross-section of the ignition flame hole, the more vaporized gas will be present and the easier ignition will occur, and if a plurality of small hole groups are formed, the flow rate of the vaporized gas will be reduced, making ignition easier. When the ignition flame hole is ignited, the temperature of the small hole 41 is low and the vaporized gas is also cooled, but the ignition source is the flame of the ignition flame hole which has much more energy than the spark of the ignition tool 14. It ignites in a short time and the generation of raw gas is greatly reduced. Therefore, by providing the ignition flame hole, the time from energizing the electric heater to ignition can be significantly shortened, and ignition delay can be prevented.

Effects of the Invention As is clear from the above explanation, according to the combustion apparatus of the present invention, a heat receiving section with a built-in electric heater is installed in the upper part of the vaporizing cylinder, which is installed upright at approximately the center of the vaporizing chamber, with numerous small holes in the wall surface and in the bottom surface. A bottomed cylindrical flame tube with a flame hole for ignition is connected so that the bottom surface touches the heat receiving part of the vaporization tube, and a vaporized gas passage is provided from the vaporization chamber to the lower part and outer periphery of the flame hole tube. With this configuration, (1) ignition is reliable and less raw gas is generated.

(2) The time from energization to ignition is short.

(3) The diameter of the combustion tube is small, allowing the combustion device to be made smaller and thinner.

(4) A stable combustion state can be obtained even when the combustion amount is small, and the combustion amount can be adjusted over a wide range.

The following effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a liquid fuel combustion apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view of a main part of a conventional combustion apparatus. 1. Vaporizing tube, 2... Electric heater, 3... Heat receiving part, 4... Flame hole tube, 4a... Small hole, 4b... Flame hole for ignition, 5... Vaporizing gas Passage, 6... Combustion chamber. Name of agent: Patent attorney Toshio Nakao and 1 other person/-
--Kii Otsujo 2-゛Electric heater Figure 1

Claims (3)

[Claims] (1) A bottomed cylindrical flame with many small holes in the wall and ignition holes in the bottom of the bottomed cylindrical vaporizing cylinder, which has a heat receiving part with a built-in electric heater standing upright in the center. A liquid fuel combustion device, wherein the hole tubes are connected so that the bottom surface is in contact with the heat receiving part of the vaporization tube, and a vaporized gas passage is provided from the vaporization chamber in the vaporization tube to the outer peripheral part of the flame hole tube from the lower part of the flame hole tube. (2) The liquid fuel combustion device according to claim 1, wherein the cross-sectional area of the ignition flame hole is larger than the cross-sectional area of the small hole in contact with the wall surface. (3) The liquid fuel combustion device according to claim 1, wherein the ignition flame hole is comprised of a plurality of small hole groups.