JPS6131763B2 - - 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 obtain 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 4 of the fuel supply body 1, which sucks up 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.

20 is a burner housing that forms a mixing chamber/combustion chamber 21 surrounding the upper part of the vaporizing wick 15 and a main combustion chamber 22, and is located on both sides of an outer chamber plate 22 which is bent into a substantially U-shaped cross section as shown in FIG. A side wall plate 23 is fixed to the surface, and an inner wall plate 24 is fixed to the inside and upper surface of the side wall plate 23 to form a hollow box shape. The burner housing 20 has primary air holes 2 in both combustion chamber walls communicating with a hollow part 26.
7, 27a, and a large number of secondary air holes 28 are formed, and air is supplied from these air holes 27, 27a, 28 to vaporize the fuel in the vaporization wick 19 facing into the mixing chamber/combustion chamber 21. It is designed to let it burn. Among these air holes, primary air holes 27, 2
7a, especially the first stage rear air hole 27, the 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 the two air holes 27, 27a, the left and right air holes in the first stage are opposed to each other, and those in the second stage are shifted in position in a staggered arrangement. Further, at least one of the left and right air holes 27 of the first stage is set to be located opposite to the notch 15a provided in the vaporizing wick 15.
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, and the opening 30 faces and matches the oil chamber 4 of the twist supply unit 1 in the fuel supply unit. It is mounted and fixed on the top surface.
Four air holes 33 are formed in the bottom surface of the hollow portion 26 of the burner housing 20.
3 matches the four air holes 34 provided on the upper surface of the fuel supply unit body 1, and air is obtained from an air supply pipe 35 with an air amount variable damper 35a connected to the lower part of the heat exchanger. ing.

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 in the longitudinal direction of the mixing chamber/combustion chamber 21 so as to face each other. It is bent downward at an inclination angle of about 40 degrees from a position slightly above 27a and is inclined 40b. This downwardly bent piece 40b has a notch 41a in a portion facing the second stage primary air hole 27a, and a protruding portion 41 is provided in the portion facing the first stage primary air hole 27.
It is listed as b. Further, an opening 42a for escape of the heater is formed in the flame holding plate 40 on the side from which the ignition heater 38 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 6 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 burned by the primary air from the primary air holes 27 and 27a, but most of it rises as it is and is supplied from the secondary air hole 28. secondary air is obtained, 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 to be 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, the vaporizing wick 15
The first stage primary air hole 2 facing the notch 15a of
7, the flames from the left and right cross each other at the notch 15a. Therefore, at the time of ignition, even if the ignition flame is formed in only one of the left and right primary air holes 27, the ignition flame will instantly spread to both the left and right sides due to the effect of the cross, and from the ignition. The transition to normal combustion will occur more quickly. Furthermore, at the time of ignition, the air ejected from the second-stage primary air hole 27a spreads along the flame holding plate 40, creating an air curtain of air only, making it difficult for fire to spread. Since the opening 42b is formed in the opening 40, the air curtain flow is directed through the opening 42b.
The flame formed in the first stage primary air hole 27 is sucked into this rising air current, and this air curtain flow mixes with the vaporized gas, making it easier to ignite. That is, the presence of the opening 42b further improves the ignition performance.

On the other hand, when ignition is completed in this manner, normal combustion begins as described above. At this time, the primary air hole 27
The flame that is formed collides with the side surface of the vaporizing wick 15 and spreads to the left and right, and the flame comes into contact with the adjacent flame to form a flame band on the surface of the vaporizing wick. For this reason, the tar that tends to occur on the surface of the vaporizing wick will be formed almost uniformly and thinly over the entire surface of the vaporizing wick, and will not be concentrated locally and become impossible to extinguish by dry firing. It has the advantage that the wicking performance of its vaporizing wick can be maintained for a long period of time by 1.5 times. This requires that the flame be formed in the form of a band on the side of the vaporizing wick, and if the flame is formed locally, it will have a very short lifespan. In addition to reducing the hole pitch as in the embodiment, possible means for forming the flame into a band shape include increasing the hole diameter and bringing the hole closer to the side surface of the vaporizing wick. Good too.

On the other hand, the flame formed in the second-stage primary air hole 27a holds the flame formed in the first-stage primary air hole 27 as described above, but the second-stage primary air hole 27a holds the flame formed in the first-stage primary air hole 27a. Since the primary air holes 27 are provided at a ratio of one to two, they act efficiently on all the flames formed in the first stage primary air holes 27, reducing pulsating combustion in the low combustion range. This has the effect of extending the low combustion range to even lower locations.

On the other hand, as described above, since this combustion device has a large number of first and second stage primary air holes 27 and 27a, the amount of vaporized fuel from the vaporizing wick 15 inevitably increases, and the atmosphere in the primary flame formation area increases. The temperature becomes high. In addition to this, the second stage primary air hole 27a
Since the flames formed in the air holes 27a come into contact with each other, the temperature becomes particularly high. For this reason, the vaporized fuel rising from the first-stage primary air hole 27 without being completely burned is thermally decomposed between the primary air holes 27a, which tends to generate yellow flame, soot, and the like. In other words, when the amount of combustion is increased, yellow flame, soot, etc. are more likely to be generated. However, in this combustion apparatus, the protruding part 41b of the flame stabilizing plate 40, which is in a relatively low temperature state due to contact with the air from the second stage primary air hole 27a, is located in the high temperature part and lowers the temperature of this part. Become. Therefore, even though the combustion amount is high, good combustion can be expected with less generation of yellow flame, soot, etc. Further, the protruding portion 4 of the flame stabilizing plate 40
1b diffuses the mixed gas of vaporized fuel and air rising from the vaporizing wick 15, which has the advantage of improving the combustion state. In addition, this protrusion 41
The combustion width is expanded due to the diffusion effect of b, and the combustion condition during extinguishing becomes stable and good.

In addition, the presence of the bent portion 40a of the flame stabilizing plate 40 promotes the diffusion of the vaporized mixed gas in the combustion chamber 21 and converges it to the center, thereby improving the combustion characteristics from ignition to steady state and extinguishing. In particular, soot generation during ignition and extinguishing is reduced. Furthermore, the bent portion 40a also serves as reinforcement for the flame-holding plate, suppressing thermal deformation, and has the effect of ensuring stable combustion over time. Furthermore, since the edge of the notch 40b of the flame stabilizing plate 40 is located slightly below the second stage primary air hole 27a, the flame formed in the primary air hole 27a protrudes upward and inward from the edge. If the operation is restarted during the extinguishing process, that is, when the combustion flame has subsided and the vaporizing wick 15 has become red hot and is in the process of dry firing, the flame formed in the primary air hole 27a will be removed from the secondary air hole 28 part. There is also the advantage that the flame transfer occurs smoothly, eliminating the explosion phenomenon caused by delayed flame transfer, and improving safety.

As described above, according to the present invention, a belt-shaped flame is formed on the surface of the vaporizing wick, and the tar generated is dispersed, and only enough tar is generated to be removed by dry burning.
Combustion performance can be maintained well over a long period of time.
Moreover, since the vaporization wick contains liquid fuel in a liquid phase, the amount of vaporization, that is, the amount of combustion, changes depending on the amount of air. effective.

[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, Figure 6 is a plan view taken along B-B' in Figure 2, Figure 7a is C-O-O'- in Figure 6.
The cross-sectional plan view of C′, FIG. 7b is D-O- in FIG.
It is a sectional plan view taken along O'-D'. 15... Vaporization wick, 27, 27a... Air supply means (primary air hole), 38... Ignition heater.

Claims (1)

[Claims] 1. A heat-resistant porous vaporizing wick containing liquid fuel in a liquid phase, an air supply means for supplying air to the vicinity of the vaporizing wick, and an air supply means disposed near the vaporizing wick to supply the vaporized fuel from the vaporizing wick. and an ignition heater for igniting the liquid, and the air supply means is configured such that the flame formed by the air flow from the air supply means is continuous in a band shape on the surface of the vaporizing wick. Fuel combustion equipment.