JPS6132568B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid fuel combustion device in which air is applied to a vaporization element impregnated with liquid fuel, and an amount of liquid fuel corresponding to the amount of air is vaporized and burned from the vaporization element. The purpose is to reduce the yellow flame that occurs during the transition period during ignition and extinguishing, prevent deterioration of combustion due to soot accumulation, and ensure good combustion over a long period of time.

An example of this will be explained below with reference to the drawings.
Reference numeral 1 denotes a long linear fuel supply unit built into the lower part of the heat exchange case 2, which is made of aluminum die-casting with good thermal conductivity, and whose upper peripheral edge 3 is fitted into the wall of the heat exchange case. It is fixed in an airtight state.

An oil chamber 4 with an open upper surface is integrally formed approximately in the center of the fuel supply body 1, and an oil reservoir chamber 6 communicating through a slit hole 5 is integrally formed on the side of the oil chamber. be. As shown in FIG. 3, this oil reservoir chamber 6 is divided into three chambers 8, 9, and 10 by a partition wall, and the fuel flows from the fuel pipe 11 connected through the heat exchanger wall as indicated by the arrows a, b. The excess fuel flows into the oil chamber 4 as shown in FIG. 3C, and at the same time, the excess fuel overcomes the weir 13 that keeps the oil level constant and flows out into the return pipe 14 to the fuel tank (not shown). Reference numeral 15 denotes a vaporizing wick inserted into the oil chamber 7 of the fuel supply unit body 1, which sucks up the liquid fuel accumulated in the oil chamber 4 by capillary action and contains it in a liquid phase. There is. This vaporizing core 15 is made of petalite (alumina approx.
A mixture of 50% by weight, 100% by weight of silica, 10% by weight of Cobalon, 10% by weight of starch, 3% by weight of barium oxide, and 12% by weight of polyvinyl alcohol is molded and baked at approximately 1250℃. After firing, it consists of 100% by weight of petalite (about 50% by weight of alumina, about 50% by weight of silica) and 3% by weight of barium oxide, and the other components are fired to create the vent.

Further, this vaporizing wick 15 has a U-shaped notch 15a formed on the top surface facing an ignition heater, which will be described later. Reference numeral 16 denotes a holder for holding the vaporizing wick 15, which covers the lower outer surface of the vaporizing wick 15 as shown in FIG.
7 is suspended by being engaged with recesses 18 provided on both side opening edges of the oil chamber 4. As a result, a fuel passage gap t is formed between the bottom of the vaporizing wick and the bottom of the oil chamber, and the fuel from the slit hole 5 spreads over the entire area of the vaporizing wick 15 through this gap t. Note that this fuel is drawn up into the vaporizing wick 15 through an opening 19 provided on the lower surface of the holder 16.

Reference numeral 20 denotes a burner housing forming a mixing chamber/combustion chamber 21 surrounding the upper part of the vaporizing wick 15 and a main combustion chamber 22, which is located on both sides of an outer chamber plate 22a which is bent into a substantially U-shaped cross section as shown in FIG. A side wall plate 23 is fixed to the surface,
An inner wall plate 24 is fixed to the inner side and upper surface of the box to form a hollow box shape. The burner housing 20 has a large number of primary air holes 27, 27a and secondary air holes 28 formed in both combustion chamber walls that communicate with the hollow part 26, and air is supplied from these air holes 27, 27a, 28. The fuel in the vaporizing wick 15 facing into the mixing chamber/combustion chamber 21 is vaporized and combusted. Among these air holes, primary air holes 27, 2
7a, especially the first stage air hole 27,
The flame formed from this collides with the side surface of the vaporizing wick 15, and the flame spreads from side to side to form a belt-like pitch, for example, about 6 mm. The air holes 27a in the second stage are formed at appropriate intervals, for example, at a ratio of one to two air holes 27 in the first stage, for the purpose of stabilizing the flame from the first stage. 27a are formed on the same line. Furthermore, among these air holes 27, 27a, the left and right air holes 27 in the first stage are opposite to each other, and the air holes 27a in the second stage are shifted in position in a staggered arrangement. In addition, the first stage air hole 27
At least one of the left and right ones is vaporized wick 15
It is set so as to be located opposite to the notch 15a provided in the. On the other hand, the burner housing 20 has an opening 30 facing the mixing chamber/combustion chamber 21 on the bottom surface of its outer wall plate.
It is mounted and fixed on the upper surface of the fuel supply unit body so as to face and match with the fuel supply unit body. And the hollow part 2 of the burner housing 20
6. Four air holes 33 are formed on the bottom surface of the fuel supply unit 1, and these air holes 33 match the four air holes 34 provided on the top surface of the fuel supply body 1, and the air holes connected to the lower part of the heat exchanger Air is obtained from an air supply pipe 35 with a damper 35a for variable quantity.

Reference numeral 37 designates a heater guide that extends through the side of one of the hollow portions 26 of the burner housing 20, into which an ignition heater 38 that projects above the notch 15a of the vaporizing wick 15 is fitted so as to be freely insertable and removable. Reference numeral 40 denotes a flame stabilizing plate attached to the left and right walls of the mixing chamber/combustion chamber 21 so as to face each other in the longitudinal direction. The angle of inclination is approximately from a position slightly above the primary air hole 27a of the eye.
It is bent downward at 40 degrees and sloped 40b. This downward bent piece 40b is the second stage primary air hole 2.
A notch 41a is provided in a portion facing the primary air hole 7a, and a protruding portion 41b is provided except for the portion facing the first stage primary air hole 27. Furthermore, the ignition heater 38
An opening 42a for escaping the heater is formed in the flame holding plate 40 on the side from which the flame holding plate 40 projects, and an opening 42b facing this opening 42a is formed in the other flame holding plate 40. Note that consideration is given so that no primary air hole 27 exists in the combustion chamber wall facing this opening 42b.

Reference numeral 44 denotes a flame regulating plate fixed to the upper surface of the burner housing 20, and an opening 45 facing the upper opening edge of the main combustion chamber 22 is formed approximately in the center. This opening 45 is formed smaller than the upper opening of the main combustion chamber 22, and is set so that its opening edge protrudes inward over the entire circumference.

In the above configuration, the liquid fuel supplied to the oil reservoir chamber 7 enters the oil chamber 4 through the slit hole 5 and is sucked up into the vaporizing wick 15 by capillary action. The air supplied from the air supply pipe 35 is supplied to the air hole 3.
The primary and secondary air holes 27, which enter the hollow part 26 of the burner housing 20 through the combustion chamber walls 3 and 34
Each combustion chamber 21, according to the cross-sectional area ratio of 27a, 28
22. At this time, the air from the primary air hole 27 hits the surface of the vaporizing wick 15.
evaporates the fuel contained in it and mixes it with it.
Therefore, when the ignition heater 38 is energized to make the element 38' red-hot, the heat ignites and starts combustion. The amount of vaporization increases due to this combustion heat, and a part of it is combusted by the primary air from the primary air holes 2 and 27a.
Most of the air rises as it is and obtains secondary air supplied from the secondary air hole 28, resulting in green combustion.

Here, the size of the above combustion flame is the primary air hole 2.
It is determined by the amount of air supplied from 7 and 27a. In other words, the air supplied near the vaporizing wick mixes with the vaporized fuel from the vaporizing wick 15 to create a mixed gas in the flammable range, but the larger the amount of air supplied, the smaller the amount of mixed gas in the flammable range. The less it becomes. Therefore, the size of the combustion flame is proportional to the amount of air supplied. The amount of vaporized fuel vaporized from the vaporization wick 15 is proportional to the size of the combustion flame (the amount of heat). Therefore,
In this combustion device, if the amount of air supplied is changed, the amount of combustion will change accordingly. The amount of air and the amount of fuel always maintain a substantially constant relationship (the air-fuel ratio is substantially constant), resulting in good combustion.

In such a combustion device, especially since this type of burner uses a diffusion combustion method, in the combustion region during transition periods such as ignition and extinguishing, the mixing chamber/combustion chamber 2
When the vaporized gas and air are mixed in the chamber 1, the uniformity of the concentration and mixture distribution tends to deteriorate in some areas, and yellow flame combustion and soot are likely to occur. Therefore, as in this embodiment, by providing the bent portion 40a of the flame stabilizing plate 40, the diffusion effect of the vaporized mixed gas in the combustion chamber 21 is promoted. That is, the vaporized mixed gas rising through the opening between the left and right flame stabilizing plates 40 causes a large vortex at the upper part of the flame stabilizing plate 40, that is, the upper part of the mixing chamber/combustion chamber 21, and the mixing action is performed to some extent. However, the vortex effect is doubled when multiple stages are provided, and these conditions are essential for this type of burner. Therefore, by providing the bent part 40a on the upper part of the flame stabilizing plate 40, the mixing action by the eddy current acts in two stages with this bent part 40a as a boundary, and the vaporized mixed gas is uniform in concentration distribution. In addition, since the retention volume of the vaporized mixed gas is halved and the vortex action is moved away from the wall surface, the combustion characteristics are improved without any variation in the mixing characteristics in the combustion region during the transition period, and the generation of yellow flame combustion and soot in the extreme regions is improved. is reduced. Furthermore, even if soot adheres to the wall near the bent portion 40a, each time the fire is extinguished, the flame stabilizing plate 40 and the bent portion 40a receive the heat of the flame and reach a high temperature, and the soot is burnt off by the heat, resulting in a cleaning function. Therefore, the mixing chamber/combustion chamber 21 can be maintained very effectively and soot-free for a long time, and stable combustion characteristics can be maintained. Furthermore, the bending part 40
A also has the effect of reinforcing the flame holding plate 40, suppressing thermal deformation, and ensuring stable combustion over time.

As described above, according to the present invention, yellow flame generated during the transition period during ignition and extinguishing can be reduced, combustion deterioration due to soot generation can be prevented, and good combustion can be obtained over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a liquid fuel combustion device according to an embodiment of the present invention, FIG. 2 is a side view with a side thereof partially cut away, and FIG. 3 is a plan view with the same portion cut away. , Figure 4 is a perspective view, Figure 5 is A of Figure 2.
-A' line sectional view, Fig. 6 is a plan view taken along B-B' line in Fig. 2, Fig. 7a is a C-O-
A cross-sectional plan view taken along the O'-C' line, Figure 7b is D in Figure 6.
It is a cross-sectional plan view taken along the line -O-O'-D'. 15... Vaporization wick, 27, 27a... Air supply means (primary air hole), 38... Ignition heater, 40...
...Flame holding plate, 40a...Bending part.

Claims (1)

[Claims] 1. A mixing chamber/combustion chamber, a main heating chamber provided downstream thereof, and a main combustion chamber provided at the bottom of the mixing chamber/combustion chamber,
a heat-resistant porous vaporization wick containing liquid fuel in a liquid phase; a plurality of air holes provided in the wall of the mixing chamber/combustion chamber so as to supply air to the vicinity of the vaporization wick;
an ignition heater disposed near the vaporization wick to ignite the vaporized fuel from the vaporization wick; and a flame holding plate provided in the mixing chamber/combustion chamber to hold the flame formed by the ignition of the ignition heater. 1. A liquid fuel combustion device comprising: a flame stabilizing plate having an upper part bent toward the center of a burner housing.