JPH0362965B2 - - 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.

2. Description of the Related Art As shown in FIG. 3, a conventional combustion apparatus of this type 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. A mixed gas of vaporized fuel and combustion air supplied into the vaporization cylinder 2 is led into the burner head 3 and ignited by a spark discharge from the ignition electrode 4, igniting a part of the flame hole 5. The flame spreads all around the burner head 3 to form a flame 6.

Problems to be Solved by the Invention However, in the conventional configuration described above, the premixed gas of the vaporized fuel and combustion air premixed in the vaporization cylinder 2 passes through the burner head 3 as it is with a strong swirling flow. As a result, sufficient premixing is not performed, and flames with different air-fuel ratios are formed for each flame hole 5 in the circumferential direction. Therefore, due to changes in the combustion air flow rate 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 5 are divided and provided all around the peripheral wall of the burner head 3 in this way, the flame ignited in a part of the flame holes 5 spreads to the entire circumference of the burner head 3 and ignition is completed. However, if the flame transfer is poor, such as at low temperatures, 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 4, and during that time, There was also the problem that the premixed gas ejected from the flame holes in some parts of the reactor would turn into white smoke and flow out.

The present invention solves these conventional problems, and aims to form a uniform flame over the entire circumference of the flame hole in 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 vaporization cylinder, and the perforated plate is provided with a perforated plate facing the ignition electrode. It has a structure in which a cut-out opening for bypass is provided at the position.

Effects According to the present invention, the strong swirling flow of the premixed gas generated in the vaporization cylinder is relaxed by the perforated plate and mixing is promoted by the above-mentioned configuration, and this premixed gas is After ejecting from the flame hole at the opening, it will begin to eject 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, 7 is a cylindrical mixing/vaporizing cylinder with an open top (hereinafter referred to as a vaporizing cylinder), 8 is a sheathed heater embedded in this vaporizing cylinder 7, and 9 is the vaporizing cylinder 7. This is an air passage that supplies combustion air to the air blower 10, and communicates with the blower 10. A fuel pipe 11 supplies fuel to the carburetor cylinder 7, and communicates with a fuel tank 13 via a pump 12. 1
4 is a burner case surrounding the outer periphery of the vaporization cylinder 7, 15
A cylindrical burner head is attached to the upper opening of the vaporizing cylinder 7, and the upper part is covered with a cap 15a to form a ceiling cylinder shape, and the lower opening is narrowed to a small diameter and serves as a mixed gas inlet 15b. This burner head 15 has a large number of flame holes 16 provided approximately equally on its peripheral wall, and wire meshes 17 and 16 are placed on the inner and outer walls of the burner head 15, respectively.
8 is pasted on the inside and outside. Reference numeral 19 denotes a flame rod as a flame detection sensor, the tip of which hangs down to the center of the flame hole. Reference numeral 20 denotes an ignition electrode for igniting by spark discharge, the tip of which is positioned opposite to the ignition flame hole 16a. Reference numeral 21 designates a perforated plate provided in the burner head 15 so as to cover the mixed gas inlet portion 15b, and has a cut-and-raised opening 21a at a position facing the ignition electrode 20 for bypassing a portion of the mixed gas. Reference numeral 22 denotes a semicircular flow suppressing metal fitting provided in the gap between the mixed gas inlet portion 15b and the porous plate 21 on the side opposite to the ignition electrode 20. In addition, 23 in the figure is a ground plate fitted to the outer periphery of the vaporization cylinder 7.

In the above configuration, when the sheathed heater 8 is energized and the temperature of the vaporization cylinder 7 rises to a certain set value, the pump 12 supplies fuel from the fuel pipe 11 into the vaporization cylinder 7, and at the same time, the blower 10 passes the fuel through the air passage 9 and burns it. air is sent. The fuel is vaporized in the vaporization tube 7, mixed with combustion air, and ejected from the flame hole 16. This premixed gas is then ignited by a spark discharge from the ignition electrode 20 to form a flame 24. At this time, since the flame 24 is formed, a flame current flows between the flame rod 19 and the earth of the burner head 15, the earth plate 23, etc., and the flame is detected.

Here, when the premixed gas mixed in the vaporization cylinder 7 flows into the burner head 15 from the mixed gas inlet 15b with a strong swirling flow, a part of the premixed gas flows through the cut-and-raised opening 21a for bypass. While ejecting from the ignition flame hole 16a near the ignition electrode, most of the premixed gas stagnates due to the pressure loss between the flow suppressing fitting 22 and the perforated plate 21, promoting mixing, and being uniformly dispersed through the perforated plate 21. The flame passes through and comes to be ejected from the flame hole 16 in the peripheral wall of the burner head 15. 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.

In addition, with this configuration, the ignition flame hole 1 at the time of ignition
Since the premixed gas flowing out from the flame hole 6a reaches the flame hole earlier than the premixed gas flowing out from the other flame holes 16, a flame is first formed in the ignition flame hole 16a and becomes a pilot flame, Since the flame moves sequentially to the flame holes 16 of the ignition flame hole 1 before the pilot flame is formed,
Premixed gas does not leak out unintentionally from the flame holes 16 other than 6a, that is, white smoke is not generated, and the characteristics at the time of ignition (for example, combustion exhaust gas characteristics, fire circulation, etc.) are also improved. In particular, this embodiment is effective because it is provided with the current restraining metal fittings 22.

Furthermore, in this embodiment, the bypass cut-and-raised opening 21a has a small area (in this case, an area of 1/10 or less of the total opening area of the perforated plate 21), so that the flow of water through the bypass cut-and-raised opening 21a is small. The amount of mixed gas is not so large, and the amount of premixed gas ejected from the flame hole on the side where this cut-and-raised opening 21a for bypass is provided is large, in other words, the flame of the flame hole on the side where this cut-and-raised opening 21a for bypass is provided This eliminates the inconvenience of lift inflammation being more pronounced than in other areas.

Although the above embodiment has been described with reference to a combustion apparatus using liquid fuel, the same applies to a combustion apparatus using gaseous fuel, and what corresponds to the vaporization cylinder 7 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 that a uniform flame is formed all around the burner head. 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 drawings]

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. 7... Carburizer cylinder, 15... Burner head, 16...
... Flame hole, 20 ... Ignition electrode, 21 ... Perforated plate, 2
1a... cut and raised opening, 22... flow suppressing fitting.

Claims (1)

[Claims] 1. A vaporizing cylinder having an opening, a burner head attached to the opening of the vaporizing cylinder, and an ignition electrode provided on the outer periphery of the burner head, and a large number of flames are arranged around the entire circumference of the peripheral wall of the burner head. In addition to providing a hole, a perforated plate is provided in the front side of the flame hole inside the burner head, and a cut-out opening is provided in the perforated plate at a position facing the ignition electrode, so that a hole can be opened from the flame hole facing the ignition electrode. A combustion device in which the mixed gas is ejected earlier than the mixed gas ejected from other flame holes. 2. The combustion device according to claim 1, further comprising a semicircular flow suppressing fitting provided between the burner head and the perforated plate on the side opposite to the ignition flame hole.