JPH0330049B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a premix combustion device used in oil fan heaters and the like.

BACKGROUND ART Conventionally, this type of combustion apparatus is constructed by covering the upper opening of a vaporizer cylinder 2 in which a heater 1 is embedded, with a burner head 3 in the form of a canopied cylinder, as shown in FIG. A mixed gas of vaporized fuel and combustion air supplied into the burner head 2 is guided into the burner head 3, and is ejected from the flame hole 3a to form a flame 4.

Problems to be Solved by the Invention However, in the above configuration, the vaporizer cylinder 2
The premixed gas of vaporized fuel and fuel air that has been premixed in the burner head 3 passes through the burner head 3 in its premixed state, so sufficient premixing is not performed, and the premixed gas is Flames with different air-fuel ratios are formed. Therefore, due to changes in the amount of combustion air or fuel flow rate, a flame with a large air-fuel ratio tends to be in a lifted state, and conversely, a flame with a small air-fuel ratio tends to generate yellow flame.
In addition, when the flame holes 3a are provided all around the peripheral wall of the burner head 3, the flame ignited in a part of the flame holes 3a spreads to the entire circumference and ignition is completed, but when the temperature is low, etc. When flame transfer is poor, it takes time for the flame to spread to all the flame holes, especially to the flame hole on the side opposite to the ignition electrode (not shown), and during that time, the flame erupts from the flame hole on the side opposite to the ignition electrode. There was also the problem that the premixed gas would flow out as white smoke.

The present invention solves these conventional problems, and aims to form a uniform flame over the entire circumference of the flame hole on the peripheral wall of the burner head, and at the same time eliminate ignition white smoke.

Means for Solving the Problems In order to solve the above problems, the present invention provides a perforated plate in the burner head that covers the inlet of the premixed gas from the vaporizing cylinder and a mixing cylinder in the form of a ceiling cylinder that covers the perforated plate. The perforated plate has a non-porous part facing the mixed gas inlet, and the mixing tube has an opening in the ceiling part opposite to the non-porous part of the perforated plate, and has an opening in the peripheral wall part facing the ignition electrode. The configuration includes a bypass opening.

Effects According to the present invention, with the above configuration, premixing of vaporized fuel and combustion air is performed not only inside the vaporization cylinder but also inside the mixing cylinder, and furthermore, this premixed gas is distributed to the portion near the bypass opening of the mixing cylinder. After ejecting from the flame hole, it will start ejecting from other flame holes.
Therefore, a uniform flame is formed over the entire circumference of the flame hole in the peripheral wall of the burner head, and white smoke due to delayed flame transfer is also eliminated.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In FIGS. 1 and 2, 5 is a low cylindrical mixing/vaporizing cylinder with an open top (hereinafter referred to as a vaporizing cylinder), 6 is a sheathed heater embedded in this vaporizing cylinder 5, and 7 is the vaporizing cylinder 5. It is an air passageway that supplies combustion air to the air blower 8 and communicates with the blower 8. 9 is a fuel pulp that supplies fuel to the carburetor cylinder 5, and a pump 10
It communicates with the fuel tank 11 via. 12 is a burner case surrounding the outer periphery of the vaporizing cylinder 5; 13 is a cylindrical burner head attached to the upper opening of the vaporizing cylinder 5; the upper part is covered with a cap 13a to form a cylinder shape with a ceiling; the lower opening is a small diameter burner head; It is narrowed down to the mixed gas inlet 13b. This burner head 1
3 has a large number of flame holes 14 provided approximately equally on its peripheral wall, and wire meshes 15 and 16 are attached to the inner and outer walls of each of the inner and outer walls, respectively. Reference numeral 18 designates a flame rod as a flame detection sensor, the tip of which hangs down at the center of the flame hole. 19 is an ignition electrode that ignites by spark discharge, the tip of which is an ignition flame hole 14
It is located opposite to a. Reference numeral 20 denotes a cylindrical mixing cylinder with a ceiling provided in the burner head 13, and is provided so as to cover the mixed gas inlet 13b.
1 is provided. This perforated plate 21 has a portion facing the mixed gas inlet 13b as a non-porous portion. The mixing cylinder 20 is provided with an opening 20a in a portion facing the non-porous portion of the perforated plate 21, and a small bypass opening 20b in a peripheral wall portion facing the ignition electrode 19. The opening 20a has a diameter smaller than that of the mixed gas inlet 13b, and a perforated plate 2 is attached to the edge of the opening 20a.
A cylindrical portion 20c protruding toward the first side is formed. In addition, 22 in the figure is a ground plate fitted to the outer periphery of the vaporizing cylinder.

In the above configuration, when the sheathed heater 6 is energized and the temperature of the vaporization cylinder 5 rises to a certain set value, fuel is supplied from the fuel pipe 9 into the vaporization cylinder 5 by the pump 10, and at the same time, the blower 8 passes the fuel through the air passage 7 and burns it. air is sent. The fuel is vaporized in the vaporization cylinder 5, mixed with combustion air, and ejected from the flame hole 14. This premixed gas is then ignited by a spark discharge from the ignition electrode 19,
A flame 23 is formed. At this time, since the flame 23 is formed, a flame current flows between the flame rod 18 and the earth of the burner head 13, the earth plate 22, etc., and flame detection is performed.

Here, when the premixed gas mixed in the vaporization cylinder 5 flows into the mixing cylinder 20 from the mixed gas inlet 13b, it first collides with the non-porous part of the perforated plate 21, and is dispersed around the non-porous part. It passes through the plate 21. A part of this premixed gas is ejected from the flame hole 14a near the ignition electrode via the bypass opening 20b, and most of the premixed gas flows from the periphery of the mixing tube 20 to the central opening 20a and flows into the burner head. 13 and the flame hole 14 in the burner head peripheral wall.
It starts gushing out. Therefore, the vaporized fuel and the combustion air are mixed very well, and a uniform flame is formed all around the burner head. That is, even if the air-fuel ratio is slightly unbalanced, only a part of the flame will not be in a lifted state or a yellow flame state. Therefore, it is possible to obtain good combustion characteristics (eg, combustion exhaust gas characteristics, combustion range, etc.) over a wide range of air-fuel ratios. Further, the inside of the burner head 13 is divided by a mixing cylinder 20, and an opening 20
Since it has a complicated structure in which the perforated plate 21 communicates with the inside of the mixing cylinder 20 through the holes 20a and 20b, it acts as a kind of muffler, and the vaporizer cylinder 5
At the same time, the sound generated when the liquid fuel vaporizes inside the engine is attenuated, and at the same time, it no longer resonates with the combustion sound and generates loud noise.

In addition, with this configuration, the mixing cylinder 20
The ignition flame 14a passes through the bypass opening 20b of
Since the premixed gas flowing out to the flame hole reaches the flame hole earlier than the premixed gas flowing out from the other flame holes 14, a flame is first formed in the ignition flame hole 14a and becomes a pilot flame, Since the flame sequentially moves to the flame holes 14 of the ignition flame hole 14 before the pilot flame is formed,
The unburned premixed gas will not flow out from the flame holes 14 other than a, that is, the generation of white smoke will not occur, and the characteristics at the time of ignition (e.g. combustion exhaust gas characteristics,
Fire circulation, etc.) will also improve.

Furthermore, in this embodiment, the bypass opening 20
Since b is a small opening (here, an opening smaller than 1/5 of the opening 20a), this bypass opening 20b
The amount of premixed gas flowing out through the bypass opening 20b is not so large, and the amount of premixed gas jetting out from the flame hole on the side where this bypass opening 20b is provided is large. The inconvenience that the flame becomes significantly larger than the flame in other parts is eliminated.

Although the above embodiment has been described using a combustion apparatus that uses liquid fuel, the same applies to a combustion apparatus that uses gaseous combustion, and what corresponds to the vaporization cylinder 5 in this case is simply a mixing cylinder.

Effects of the Invention As is clear from the above description of the embodiments, according to the present invention, the premixing of fuel and combustion air is improved, so a uniform flame is formed all around the burner head, and the combustion range is also improved. It becomes wide. Moreover, the premixed gas is ejected from the flame holes other than the flame hole facing the ignition electrode later than from the flame hole facing the ignition electrode, so there is no generation of white smoke etc. due to delayed flame transfer. The effects are significant, such as improved ignition characteristics.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of a main part of a combustion apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view showing the overall structure of the same, and FIG. 3 is an enlarged sectional view of a main part of a conventional combustion apparatus. 5... Carburizer cylinder, 13... Burner head, 13b
...Mixed gas inlet, 14... Flame hole, 14a...
Ignition flame hole, 19... Ignition electrode, 20... Mixing cylinder, 20a... Opening, 20b... Bypass opening,
21...Perforated plate.

Claims (1)

[Claims] 1. A vaporizer cylinder having an opening, a burner head in the form of a ceiling cylinder that covers the opening of the vaporizer cylinder, and flame holes provided approximately evenly around the entire circumference of the inner wall of the burner head,
Equipped with an ignition electrode facing a part of this flame hole,
Inside the burner head, there is provided a perforated plate that covers the mixed gas inlet from the vaporization cylinder, and a ceiling-shaped mixing cylinder that covers this perforated plate, and the perforated plate has a non-porous part facing the mixed gas inlet. At the same time, the mixing cylinder has an opening in the part facing the non-porous part of this perforated plate,
The combustion device further includes a bypass opening provided in a peripheral wall of the mixing cylinder facing the ignition electrode.