JPS6199007A - Liquid fuel combustion device - Google Patents

Abstract

PURPOSE:To enable maintenance of excellent exhaust gas characteristics even when there is a low combustion amount, by a method wherein the distance in a longitudinal direction of the cross section of a flat combustion chamber is gradually decreased from a lower part toward an upper part. CONSTITUTION:The sectional area of a combustion chamber 2 is gradually decreased from the position of a wick 1 to upward. This causes fuel evaporated gas to be spread throughout the whole of the combustion chamber 2, and ensures and uniformizes stabilization of flame in the vicinity of the wick, resulting in a rapid increase in an amount of fuel evaporated and causes combustion to be brought into a constant state in a short time. When the opening rate of a shutter 9 for varying a combustion amount is decreased to decrease an amount of the air flowing to the combustion chamber to decrease a combustion amount, an amount of fuel evaporated at both ends of the wick 1 is extremely decreased over that at a central part when a combustion amount is low. But, since the sectional area of the combustion chamber 2 is gradually decreased to upward, the velocity of flow and the pressure of combustion gas in a longitudinal direction of the flat combustion chamber 2 are brought to a flat distribution state, and a combustion state is also uniformized. This enables shortening of a time, in which combustion is brought to a constant state after ignition, and improvement of exhaust gas characteristics, and prevent the production of a yellow flame and soot at the side part of the combustion chamber when a combustion amount is low.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a wick vaporization type liquid fuel combustion device having a flat combustion chamber, which can be used in porta-pull kerosene stoves, kerosene fan heaters, etc. .

BACKGROUND OF THE INVENTION In a conventional lamp wick vaporization type liquid fuel combustion device having a flat combustion chamber, vaporized fuel is fed from a lamp wick 1 as shown in Fig. 2.
A perforated plate 2a forming a combustion chamber 2.

The combustion reaction is completed by premixing or combustion with the air flowing in through the pores provided in the incandescent body 2b, and by mixing the air all at once through the secondary air slit 3 installed at the upper end of the combustion chamber 2. Ta.

Problems to be Solved by the Invention In such conventional liquid fuel combustion devices, there are nine problems, firstly, flame extension immediately after ignition.

In other words, even if the flame spreads throughout the entire wick after ignition, the amount of fuel vaporized is still insufficient, and even though it mixes with the air flowing in from the pores, the total flow rate is insufficient for the cross-sectional area of the combustion chamber. In addition, standing flame and diffusive combustion become dominant in the combustion chamber due to the draft of the combustion gas itself. As shown in Figure 3,
The standing flame 5 in the combustion chamber continues until the amount of fuel vaporized reaches a steady state. During that time, the tip of the standing flame 6 comes into contact with the secondary incandescent body 4, and a large amount of combustion reaction intermediate products are released, which changes the exhaust gas characteristics. The second problem was the occurrence of yellow flame in the side parts of the combustion chamber during steady combustion. In a flat combustion chamber, heat tends to escape to the sides, and the amount of fuel vaporized at both ends of the wick is considerably smaller than at the center, especially when the amount of combustion is small.

Therefore, although the combustion gas is mixed with the air flowing in from the pores of the perforated plate 2a forming the combustion chamber, the total flow rate of combustion gas at the side portions of the combustion chamber is smaller than that at the center portion. However, the cross-sectional area of the combustion chamber is constant in the height direction. Therefore, in the combustion chamber, which is under negative pressure due to the draft caused by the high-temperature gas in the upper part of the combustion chamber, there is a strong negative pressure tendency, especially in the side portions. Therefore, conversely speaking, the velocity of the inflowing air from the pores of the perforated plate 2a increases at the side portions of the combustion chamber, and the air rushes into the gas with a very low air-fuel ratio near the center in the width direction of the combustion chamber. , there is a high risk of yellow fire occurring. In particular, the incandescent body 2b has a large aperture ratio, and the amount of air flowing into the strong negative pressure part at the side part of the combustion chamber is excessive compared to the central part, so that the generation of the yellow flame is essential. As shown in Figure 3,
When the amount of combustion is small, yellow flame 6 always occurs in the side parts of the combustion chamber, and a large amount of soot is released into the exhaust gas, making it impossible to maintain good exhaust gas characteristics.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention is configured such that the longitudinal distance of the cross section of the flat combustion chamber decreases from the bottom to the top.

Effect of the present invention Due to the above-described structure, the fuel vaporized gas rapidly spreads throughout the combustion chamber even immediately after ignition, eliminating the conventional standing flame, and furthermore, the pore combustion in the lower part of the combustion chamber, near the lamp wick, spreads over the length of the combustion chamber. Since the fuel vaporization is performed uniformly in the direction, the time required for the amount of fuel vaporized to reach a steady state is rapidly shortened.

In addition, regarding the occurrence of yellow flame at the side part of the combustion chamber during steady combustion, especially when the combustion amount is low, the gas flow rate at the side part of the combustion chamber is insufficient due to the small cross-sectional area of the combustion chamber at the top. is eliminated, the pressure distribution in the longitudinal direction of the combustion chamber becomes uniform, the amount of incoming air becomes uniform, there is no yellow flame in the side parts, and a good combustion state can be realized.

Example FIG. 1 shows an embodiment of the liquid fuel combustion apparatus of the present invention.

In FIG. 1, numeral 1 denotes a lamp wick, and numeral 2 denotes a flat combustion chamber consisting of a perforated plate 2a and a red-hot body 2b, from which the tip of the lamp wick 1 is exposed. The longitudinal distance of the cross section of the combustion chamber 2 decreases from the bottom to the top. Here, the red-hot body 2b is exposed to the perforated plate 2a. Further, the amount of smoldering is adjusted by the aperture ratio of the variable combustion amount shutter 9 provided at the upper end of the outer cylinder 3.

In the above configuration, first, immediately after the lamp wick 1 is ignited, even if the fire reaches the entire lamp wick 1, the amount of fuel vaporized is not sufficient compared to the steady state. However, as the cross-sectional area of the combustion chamber 2 becomes smaller as it moves upwards from the position of the lamp wick 1, the fuel vapor gas spreads throughout the combustion chamber 2, and flame holding near the lamp wick becomes reliable and uniform. The quantity increases rapidly and a steady state is reached within a fairly short time.

In the steady state of combustion, the fuel vapor gas mixes with the air flowing in from the perforated plate 2& and burns while reacting rapidly in the red-hot body 2b. The reaction heat is released as radiant heat from the incandescent body 2b through the heat-adjusting glass plate 8. Then, the combustion reaction of the P combustible gas containing the unburned components is completed at once by a large amount of air flowing in from the slit 3, and the secondary incandescent body 4 is heated by the high-temperature exhaust gas. Heat is also released from the secondary incandescent body 4 as radiant heat.

If the aperture ratio of the combustion amount variable shutter 9 is reduced to reduce the amount of air flowing into the combustion chamber and the combustion amount is reduced, the amount of fuel vaporized at both ends of the lamp wick 1 will be:
The cross-sectional area of the combustion chamber 2 becomes smaller as it goes upward, so the combustion chamber 2 becomes flat.
There is a flat distribution of combustion gas flow velocity and pressure in the longitudinal direction, and therefore the combustion state is also uniform. In other words, there is no occurrence of yellow flame in the side parts of the combustion chamber as in the conventional case, and good exhaust gas characteristics can be obtained.

Effects of the Invention As described above, according to the present invention, by oriented the flat combustion chamber upward and reducing the longitudinal distance of the cross section, the time required to reach steady state after ignition is shortened, and the exhaust gas characteristics are improved. In addition, it is possible to eliminate yellow flame and soot generation on the sides of the combustion chamber during normal operation, especially at low combustion rates, and maintain good exhaust gas characteristics.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a liquid fuel combustion device according to an embodiment of the present invention, FIG. 2 is a perspective view of a conventional liquid fuel combustion device, and FIGS. FIG. 3 is a front perspective view in a state of use. 1...Light wick, 2...Combustion chamber. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] A liquid fuel combustion device in which the longitudinal distance in the cross section of a flat combustion chamber surrounded by a perforated plate and with the tip of the wick facing toward the bottom decreases from the bottom to the top.