JPH0526090B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a liquid fuel combustion device for domestic or commercial use such as a heating appliance.

BACKGROUND OF THE INVENTION In recent years, efforts have been made to expand the variable range of the combustion amount of combustion devices while improving the exhaust gas characteristics.

As one means of achieving this, we have succeeded in greatly improving the above characteristics by using a combustion device in which a large number of flame ports are placed facing each other.

An example of the above-mentioned combustion device will be described below with reference to the drawings.

FIG. 6 is a sectional view of a conventional combustion device using opposed flames. In Fig. 6, 1 is a fuel nozzle that spouts fuel, 2 is a vaporizer tube that vaporizes fuel, and 3 is a fuel nozzle that spouts fuel.
is a heater that heats the vaporization cylinder, 4 is a mixing chamber that mixes vaporized fuel and air, 5 is a fuel passage, 6 is a fuel supply passage branched from the fuel passage, 7 is a flame port, and 8
9 is a combustion chamber wall forming a combustion chamber, and 9 is an ignition electrode.

The operation of the combustion apparatus configured as described above will be explained below.

First, when the heater 3 is energized and the vaporization tube 2 reaches a predetermined temperature, combustion air and liquid fuel are sent into the vaporization tube 2, and the liquid fuel is vaporized by the vaporization tube 2 and mixed with air. The vaporized fuel is then sent to the mixing chamber 4, where the air and vaporized fuel are sufficiently mixed. The mixed air-fuel mixture passes through the fuel passage 5 and reaches the flame port 7 from a large number of fuel supply passages 6. flame mouth 7
A flame is formed when the air-fuel mixture ejected from the air is ignited. Here, since the flame ports 7 are provided facing each other, the flames are formed facing each other as shown in FIG. As a result, even when the amount of air increases or the amount of combustion is large, flame blow-off becomes extremely difficult to occur, and the variable range of the amount of air and the amount of combustion becomes wider.

Problems to be Solved by the Invention However, with the above configuration, it takes time for the air-fuel mixture to reach the flame port 7 from the mixing chamber 4 via the fuel passage 5 and the fuel supply path 6 at the time of ignition. There is a time difference between when the air-fuel mixture exits from the upstream side flame port 7a closest to the mixture chamber 4 and when it comes out from the downstream side flame port 7b remote from the mixing chamber 4. Therefore,
When the air-fuel mixture starts to come out from the flame port where the ignition electrode 9 is placed, the combustion chamber is already filled with the air-fuel mixture, so the discharge of the ignition electrode 9 causes the above-mentioned filled air-fuel mixture to instantly flow. There was a possibility of explosion and ignition. Therefore, at that time, a sudden pressure rise in the combustion chamber may occur, which may cause damage to the gaskets, etc., or the generation of loud ignition noises, which may cause anxiety to the user and may also pose a risk of combustion gas leaking. It was hot. In addition, in order to solve this problem, if the tip of the ignition electrode 9 is extended to the flame port 7a on the upstream side, the position of the tip of the ignition electrode 9 becomes longer and cannot be accurately aligned with the flame port 7a. On the other hand, there was a possibility that the ignitability would deteriorate or the ignition electrode would be deformed by the heat of combustion, causing similar problems.

The present invention was made in view of the above problems, and it improves the positional accuracy of the ignition electrode mounting position and the ignition flame port, and also improves the positional accuracy of the ignition electrode and the ignition flame port without making the ignition electrode long. An ignition flame port is provided between opposing flame ports at the same location, and the flame is ignited before the air-fuel mixture is ejected from the other flame ports, allowing the flame to gradually propagate according to the flow of the air-fuel mixture. The purpose of this is to suppress explosive ignition and eliminate damage to gaskets and the like or generation of loud ignition noises due to sudden pressure rises.

Means for Solving the Problems In order to solve the above-mentioned problems, the combustion device of the present invention has combustion chamber walls having a large number of flame ports facing each other and arranged to face each other, and each flame port is connected to the combustion chamber through a fuel supply path. At the same time, one of the facing surfaces of the combustion chambers arranged opposite to each other is closed with a side plate, and the other side is connected to the carburetor and the fuel passage. A combustion chamber is formed by fixing a mixing chamber body with a mixing chamber body, and an ignition flame port is provided in a part of the mixing chamber body and opens toward between flame ports opening oppositely to each other in the combustion chamber, and An ignition electrode is attached so as to penetrate through the body, and the ignition electrode is provided near the combustion chamber side of the ignition flame port.

Effect The present invention has the above-described configuration, so that the air-fuel mixture sent from the vaporizer at the time of ignition enters the mixing chamber, and then first jets out into the combustion chamber from the ignition flame port provided in the mixing chamber body, and the ignition flame It is ignited by the discharge of an ignition electrode placed near the mouth. Thereafter, the air-fuel mixture that has passed through the fuel supply path from the fuel passage is sequentially ejected from the flame port near the mixing chamber, and at the same time, the flame spreads and is ignited by the flame formed at the ignition flame port, so that the air-fuel mixture is in the combustion chamber. It ignites very slowly without filling up. Therefore, there is no sudden pressure rise in the combustion chamber at the time of ignition, and no loud ignition noise is generated, so there is no fear for the user, and there is no risk of combustion gas leaking due to damage to the gaskets, etc.
In addition, since the ignition electrode attachment part and the ignition flame port are provided in the mixing chamber body, their relative positions can be determined with high accuracy, and the ignition electrode can be shortened, so there is no misalignment between the ignition flame port and the discharge part of the ignition electrode. Also, problems such as deformation of the ignition electrode due to heat are eliminated.

Embodiment The following is a first example of a combustion apparatus according to an embodiment of the present invention.
This will be explained using FIGS.

In the figure, 11 is a vaporizer that vaporizes liquid fuel, and 12 is a fuel nozzle that makes the vaporizer 11 inject the liquid fuel, which is communicated with a pump. Reference numeral 13 denotes an air passage that guides combustion air from the blower to the carburetor 11, and is open to the inlet of the carburetor 11 together with the fuel nozzle 12. A main mixing chamber 14 is provided at the outlet of the carburetor 11 and communicates with fuel passages 15 on both sides. A large number of fuel supply passages 16 branch from the fuel passage 15, and the other end of the fuel supply passage 16 penetrates the combustion chamber wall 17 and opens into the combustion chamber 18, forming a flame port 19. Here the two combustion chamber walls 1
7 are facing each other, and the flame ports 19 are provided at positions facing each other. 20 is a flame formed at the flame port 19, and the flames 20 from both sides are facing each other. Further, the fuel passage 15, fuel supply passage 16, and combustion chamber wall 17 are formed by a burner body 2 formed by bending a single sheet metal.
1, and a plurality of burner bodies 21 are connected together to form a combustion section. 22 is a side plate on which the burner body 21 and the vaporizer 11 are fixed on the opposite side of the main mixing chamber body 14; 23 is a secondary air supply pipe for flowing secondary air into the space between the burner bodies 21; It's summery. 24 is the burner body 21 and the carburetor 1
1 is fixed on the side of the main mixing chamber body 14, and has a through hole 25 approximately in the center. A holding plate 26 fixes a perforated plate 27 provided so as to cover the through hole 25, and has an ignition flame port 28 opening into the combustion chamber 18. Reference numeral 29 denotes an ignition electrode fixed such that its tip is located near the ignition flame port 28. In the figure, 30 is a heater embedded in the vaporizer 11, 31 is a burner cover that covers the outside of the burner body 21, and the space between the burner bodies is used as a secondary air supply chamber 32; A large number of air holes 33 are formed to blow out secondary air.

The operation of the combustion device configured as described above will be explained below.

First, the heater 30 is energized to heat the vaporizer 11. When the vaporizer 11 reaches a predetermined temperature, the blower is operated and combustion air is sent to the vaporizer 11 through the air passage 13. The pump also operates, and fuel is injected from the fuel nozzle 12 into the carburetor 11. Since the temperature of the vaporizer 11 is such that the liquid fuel vaporizes, the fuel is vaporized and flows from the outlet of the vaporizer 11 into the main mixing chamber body 14 while mixing with the combustion air as shown by the broken line arrow in FIG. be guided. The fuel and air in the main mixing chamber body 14 become a uniformly mixed mixture and flow into the fuel passage 15 as shown by the solid line arrow in FIG. At the same time, it reaches the ignition port 28 of the holding plate 26 from the through hole 25 of the auxiliary mixing chamber body 24 through the perforated plate 27. The air-fuel mixture ejected from the ignition flame port 28 into the combustion chamber 18 is
It is ignited by discharge from the ignition electrode 29 to form a flame. On the other hand, the air-fuel mixture that has flowed into the fuel passage 15 sequentially flows out from the side closer to the main mixing chamber body 14 of the multiple fuel supply passages 16 and is ejected into the combustion chamber 18 from the multiple flame ports 19 located on the combustion chamber wall 17. . At this time, the flames are ejected sequentially from the flame ports 19 on the side closer to the mixing chamber 14, so the flame spreads from the flame first formed in the ignition flame port 28, and from the flame port on the upstream side to the flame port on the downstream side. From right to left in Figure 1) the flame is formed.

This flame formation is caused by the combustion chamber walls 17 on opposite sides.
are carried out almost simultaneously. As a result, a large number of flames facing each other are formed, and the combustion continues stably thereafter. If we look closely at the flame formation during ignition, the air-fuel mixture is first formed at the ignition flame port 28, which is injected into the combustion chamber 18, and then the flame is formed in order from the upstream side of the flame port 19 provided in the combustion chamber wall 17. is formed. That is, since the flame propagates in the same direction as the air-fuel mixture flows, a flame is formed at the same time as the air-fuel mixture is ejected from the flame port 19. Therefore, the combustion chamber 18 is not filled with air-fuel mixture and is ignited very slowly. In addition, combustion chamber 1
There is no sudden pressure rise inside the 8, and there is no loud ignition noise. This operation becomes particularly noticeable when the combustion chamber 18 and the combustion chamber wall 17 are at a high temperature and the combustion rate is high. In other words, even a small amount of air-fuel mixture
If the mixture is ignited after remaining in the flame nozzle, the flame propagation speed will be high, and the pressure will rise accordingly, causing an explosion and ignition. Therefore, it is important to ignite the mixture at the same time as it is ejected from the flame nozzle. be.

Further, since the ignition flame port 28 is provided in a part of the auxiliary mixing chamber body 24 between the combustion chamber walls 17 arranged oppositely, it goes without saying that the air-fuel mixture is spouted out the earliest. Since the direction of the flame is perpendicular to the direction of ejection from the numerous flame ports 19, the flame propagation described above can be carried out more smoothly. Furthermore, in this embodiment, since the perforated plate 27 is arranged inside the ignition flame port 28, backfire does not occur even if the ignition flame port 28 has a relatively large diameter, and the ignition electrode 29 Problems such as misalignment of installation are eliminated.

In addition, in this embodiment, the ignition flame port 28 is connected to the perforated plate 2.
7 is provided on the holding plate 26 for fixing the mixing chamber body 24, but it may be provided on the mixing chamber body 24 as shown in FIG.

Further, although this embodiment is a combustion device that uses liquid fuel, it may also use gaseous fuel, and in that case, the vaporizer 11 becomes a mere mixer.

Effects of the Invention As is clear from the above description of the embodiments, according to the combustion apparatus of the present invention, the air-fuel mixture ejected from the flame port is ejected, and at the same time, the flame propagates due to the flame previously formed in the ignition flame port. Since the fuel is ignited very slowly, the combustion chamber is not filled with air-fuel mixture and is ignited very slowly. Therefore, the pressure within the combustion chamber does not rise suddenly during ignition, and no loud ignition noise is generated. As a result, the user will not feel uneasy, and there will be no risk of combustion gas leaking due to damage to the packing or the like. Further, problems such as misalignment between the ignition flame port and the discharge portion of the ignition electrode and deformation of the ignition electrode due to heat are eliminated.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a combustion device according to an embodiment of the present invention, as seen from the top, Fig. 2 is a perspective view of the same, Fig. 3 is a cross-sectional view taken along line A-A' in Fig. 2, and Fig. 4 is a sectional view of Fig. 3. B of
-B' sectional view, FIG. 5 is a sectional view of a main part in another embodiment, and FIG. 6 is a sectional view of a conventional combustion device. 14, 24...Mixing chamber body, 15...Fuel passage, 16
... Fuel supply path, 17... Combustion chamber wall, 18... Combustion chamber,
19... Flame port, 22... Side plate, 28... Flame port for ignition, 2
9...Ignition electrode.

Claims (1)

[Claims] 1 Two combustion chamber walls each having a large number of flame ports are arranged to face each other, and the flame ports face each other, and each of the flame ports is arranged outside the combustion chamber wall via a fuel supply path. one of the opposing surfaces between the opposingly arranged combustion chamber walls is closed with a side plate, and the other is fixed with a mixing chamber body that connects the carburetor and the fuel channel. to form a combustion chamber, and a part of the mixing chamber body is provided with an ignition flame port that opens toward between the flame ports that open oppositely to each other in the combustion chamber, and extends through the mixing chamber body. A combustion device in which an ignition electrode is attached and a tip of the ignition electrode is arranged near the combustion chamber side of the ignition flame port.