JPS62119311A - Burner - Google Patents

Abstract

PURPOSE:To suppress generation of white smoke and improve the ignitability of the titled burner by arranging an ignition electride in opposition to the open ing of a porous plate around the outer periphery of a burner head having burner ports around the entire periphery of a peripheral wall and containing therein a porous plate with slitted opening, in a premixing type burner of a kerosene fan heater or the like. CONSTITUTION:A premixed gas which has been mixed in a vaporizing cylinder 7 flows into a burner head 15 through a mixed gas inlet port 15b by accompanying a turning flow. A part of the premixing gas is ejected out of ignition burner ports 16a in the vicinity of an ignition electrode via a slitted opening 21a for bypassing, and the flow of the greater part of the premixing gas is stagnant due to pressure loss of a flow suppressing metal fitting 22 and a porous plate 21, and the mixing of the gas is promoted and becomes uniform. Thus, the mixed gas passes the porous plate 21 and is ejected through burner ports 16. by these procedures, the mixing of the vaporized fuel with combustion air is improved, and flame is formed uniformly around the entire periphery of the burner head. By this construction, generation of white smoke due to the delay in the fire shift is prevented and the ignition characteristic can be improved.

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 OF THE INVENTION As shown in FIG. 3, this type of combustion apparatus is constructed by covering the upper opening of a vaporizing cylinder 2 in which a heater 1 is embedded and a burner head 3 in the form of a ceiling cylinder. A mixed gas of vaporized fuel and combustion air supplied into the vaporization tube 2 is guided 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 at 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, in the case where 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 opposite side of the ignition electrode 4, and during that time, There was also the problem that the premixed gas ejected from the side flame holes would flow out unburned 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 in the peripheral wall of the burner head, and at the same time eliminate ignition white smoke.

Means for Solving the Problems The present invention solves the above problems by providing a perforated plate in the burner head that covers the inlet of the premixed gas from the vaporizing cylinder, and a perforated plate facing the ignition electrode. The configuration includes a cut-and-raised opening for bypass at the position where the

Effects of the present invention With the above-described configuration, the strong swirling flow of the premixed gas generated in the vaporization station is relaxed by the perforated plate and mixing is promoted, and the premixed gas flows through the flame holes in the bypass cut-out portion of the perforated plate. After it erupts from the flame, it will start ejecting from other flame holes.

Therefore, a uniform flame can be formed all around the flame hole in the peripheral wall of the burner head, and white smoke and the like due to delayed flame transfer are 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 a static passage that supplies combustion air to the air blower 10, and communicates with the blower 10. 11 is a fuel pipe that supplies fuel to the same carburetor 7;
It communicates with a fuel tank 13 via a pump 12.

14 is a burner head surrounding the outer periphery of the vaporization tube 7; 15 is a cylindrical burner head attached to the upper opening of the vaporization tube 7;
The upper part is covered with a cap 15a to form a cylindrical shape,
The lower opening is narrowed down 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 its inner and outer walls are each lined with wire mesh 17, 18 on the inside and outside. Reference numeral 19 denotes a flame rod for the flame detection sensor, the tip of which hangs down at the center of the flame hole. Reference numeral 20 denotes an ignition electrode that ignites by spark discharge, the tip of which is positioned opposite to the ignition flame hole 16a. Reference numeral 21 denotes a perforated plate provided in the burner head 15 so as to cover the mixed gas inlet 15b, and is provided with a cut-and-raised opening 21a at a position facing the ignition electrode 20 to bypass 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 15b and the porous plate 21 on the side opposite to the ignition electrode 20. In addition, the reference numeral 23 in the figure is a ground plate fitted to the outer periphery of the vaporizing 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 diffused in the vaporizing 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,
A flame 24 is formed. At this time, by forming the flame 24, the flame rod 19 and the burner head 15,
A flame current flows between the earth plate 23 and the earth, and flame is detected.

Here, the pre-warming gas mixed in the vaporization cylinder 7 flows from the mixed gas inlet 15b to the burner head 1 with a strong swirling flow.
5, a part of the premixed gas flows into the ignition flame hole te near the ignition electrode via the bypass cut-and-raised opening 21&.
While being ejected from a, most of the premixed gas stagnates in flow due to the pressure loss between the flow suppressing fitting 22 and the perforated plate 21, promoting mixing, being uniformly dispersed, passing through the perforated plate 21, and reaching the peripheral wall of the burner head 15. The flame will come out from the flame hole 16. Therefore, the vaporized fuel and the combustion air are mixed very well, and a uniform flame is formed all around the burner head. In other words, 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 will occur. 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.

Moreover, with this configuration, the premixed gas flowing out from the ignition flame hole 16a at the time of ignition reaches the flame hole earlier than the premixed gas flowing out from other flame holes 16, so that the premixed gas flows out from the ignition flame hole 16a first. A flame is formed in the ignition flame hole 16a and becomes a pilot flame, and the flame sequentially moves to other flame holes 16, so the premixed gas flows out from the flame holes 16 other than the ignition flame hole 16a before the pilot flame is formed. That is, the generation of white smoke is eliminated, 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 a current suppressing fitting 22.Furthermore, in this embodiment, the cut-and-raised opening 2 for bypass is provided.
ta is a small area (here, 1/of the total opening serum of the porous plate 21)
10 or less), the amount of premixed gas flowing out through this cut-and-raised opening 21a for bypass is not so large, and the amount of premixed gas that flows out from the flame hole on the side where this cut-and-raised opening 21a for bypass is provided. In other words, the inconvenience that the flame in the flame hole on the side where the bypass cut-and-raised opening 21 & is provided becomes a lift flame more significantly than in other parts is eliminated.

Although the above embodiment has been described using a combustion device that uses liquid fuel, the same applies to a combustion device that uses gaseous fuel, and what corresponds to the cylinder 7 in this case is a simple mixing cylinder.

Effects of the Invention As is clear from the 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 due to delayed flame transfer.
It also has great effects, such as improved ignition characteristics.

[Brief explanation of drawings]

(Fig. 1 is an enlarged cross-sectional view of a main part of a combustion device according to an embodiment of the present invention, Fig. 2 is a cross-sectional view showing the overall configuration of the same, and Fig. 3 is an enlarged cross-sectional view of a main part of a conventional combustion device).・・・・・・During vaporization, 15・・・Burner head, 1
6... Flame hole, 20... Ignition electrode, 21
...Perforated plate, 21a... Cut and raised opening, 22... Current suppressing fitting. Name of agent: Patent attorney Toshio Nakao and 1 other person/6
--Duji Jshi20-11 Shomata Electric Fox? 1-11 porous temporary

Claims (2)

[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 flame holes on the entire circumference of the peripheral wall of the burner head. and a perforated plate is provided inside the burner head, and a cut-and-raised opening is provided in the perforated plate at a position facing the ignition electrode. (2) The combustion device according to claim 1, further comprising a semicircular current suppressing metal fitting provided between the burner head and the perforated plate on the side opposite to the ignition flame hole.