JPH051803A - Liquid fuel burner - Google Patents

Abstract

PURPOSE:To hold the temperature in the vaporization section in the most suitable state in a broad range from strong combustion to weak combustion and, at the same time, improve the ignition performance. CONSTITUTION:The subject device is provided with a vaporization cylinder 4 into which liquid fuel and combustion air are applied, burner head 8 that is provided at the upper section of the vaporization cylinder 4 and has a flame port 12 in the circumferential wall section 10, and an ignition electrode 24 that ignites the mixture gas blowing out of the flame port 12. And a plurality of heat recovery projections 23, 23 that are opposite to the flame port 12 are provided at the upper section 4A of the vaporization cylinder 12 and, at the same time, the electric discharge section 24A of the ignition electrode 26 is positioned at the side position of the heat recovery projections 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an oil fan heater, F
The present invention relates to a vaporization type liquid fuel combustion device used in an F type oil hot air heater or the like.

[0002]

2. Description of the Related Art As a liquid fuel combustion apparatus of this type, for example, as disclosed in Japanese Patent Publication No. 63-45003, a vaporization cylinder having a burner head having flame holes in its peripheral wall is provided on the upper outer circumference. , A grounding plate with an annular standing wall facing the flame hole is provided to suppress the spread of the flame formed forward from the flame hole as much as possible, and the metal cylinder forming the combustion chamber is heat resistant. It is known that it is prevented from being heated to a temperature higher than the temperature.

By the way, the vaporizing cylinder of the above-mentioned conventional apparatus is
The heat generated by combustion is recovered by the upper surface exposed to the flame, and even if the vaporization heater is de-energized, the vaporization part can be maintained at a temperature at which liquid fuel such as kerosene vaporizes. However, there was a difference of about 50 to 70 ° C depending on the combustion state (strong combustion and weak combustion). That is, the heat recovery amount decreases because the high temperature part of the flame separates from the burner head in strong combustion, and conversely the heat recovery amount increases because the flame approaches the burner head in weak combustion. Further, it is said that the suitable temperature of the vaporizing section is about 260 to 350 ° C. When the temperature is 260 ° C or lower, tar easily accumulates in the vaporizing section, and when the temperature is 350 ° C or higher, particulate matter is generated in the vaporizing chamber. The non-evaporated fuel from the plant flew off, which caused a red fire. Therefore, in the conventional device, the amount of heat recovered to the vaporizing cylinder changes greatly depending on the combustion state, and the temperature of the vaporizing part changes due to this change in the amount of heat recovering, and the vaporizing part has a wide range from strong combustion to weak combustion. The temperature cannot be maintained at a suitable temperature for a long time, and there is a problem that a good combustion state cannot be maintained when trying to expand the combustion width.

Further, in the conventional apparatus, the discharge portion of the ignition electrode is provided so as to face the flame hole on the peripheral wall of the burner head, and the spark discharge from the discharge portion is blown to the edge of the flame hole for ignition. As a result, the sparks fly almost parallel to the mixed airflow ejected from the flame holes, and the air-fuel mixture in the place where the sparks fly may not be ready to ignite. It took a considerable amount of time, and the ignition performance was likely to vary.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and maintains the temperature of the vaporizing section in an optimum state over a wide range from strong combustion to weak combustion and improves ignition performance. The purpose is to

[0006]

DISCLOSURE OF THE INVENTION The present invention is directed to a vaporizing cylinder into which liquid fuel and combustion air are supplied, a burner head provided on the upper portion of the vaporizing cylinder and having a flame hole in its peripheral wall, and a flame hole. An ignition electrode for igniting the air-fuel mixture that jets out more is provided, and a plurality of heat recovery projections facing the flame holes are provided at the upper end of the vaporization cylinder, and the discharge part of the ignition electrode is provided for the heat recovery projection. It is a structure located laterally.

[0007]

With this structure, the flame becomes smaller at the time of weak combustion and approaches the flame hole portion of the burner head, so the burner head and the upper end of the vaporizing cylinder are sufficiently heated by the flame in the flame contact state, and the vaporizing portion is It can be heated and maintained at a temperature suitable for fuel vaporization. On the other hand, during strong combustion, the high temperature part of the flame separates from the flame hole part, but multiple heat recovery projections are wrapped in the high temperature part of the flame to be heated, and the heat of the heat recovery projection heated to high temperature Can be transmitted to the vaporization section, and the heat recovery amount in strong combustion can be dramatically increased.

Further, by arranging the discharge part of the ignition electrode on the side of the heat recovery projection, and by causing the spark discharge from the discharge part to fly to the heat recovery projection, this spark discharge is mixed from the flame holes. Because the airflow is always crossed, it makes wide contact with the mixed airflow,
The spark and the air-fuel mixture easily come into contact with each other in a combustible state, and the ignition can be reliably performed in a short time.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings of FIGS. In the figure, reference numeral 1 is a bottomed cylindrical burner case to which combustion secondary air is supplied from a blower 3 through a secondary air passage 2, 4 is built in the burner case 1, and a sheath heater is provided above the peripheral wall thereof. Is a bottomed cylindrical vaporization cylinder in which a heater 5 is embedded. The vaporization cylinder 4 is made of aluminum die-cast with good thermal conductivity, and a vaporization chamber 6 is formed inside. . A diaphragm plate 7 is provided in the upper part of the vaporization cylinder 4, and
A burner head 8 composed of a head main body 8A and a canopy 8B is fitted and attached to the upper end opening of the vaporization cylinder 4 on the diaphragm plate 7, and a peripheral wall 11 thereof has a plurality of flame holes 12, 12.
Is provided, and wire mesh 13 is attached to both inner and outer surfaces of the peripheral wall 11. Further, the flame holes 12, 12 have a substantially triangular shape, and the flame holes 12, 12 are
Are provided upside down alternately in the circumferential direction of the peripheral wall 11 and close to each other.

A fuel nozzle 14 for supplying liquid fuel (kerosene) to the vaporization chamber 6 and an air nozzle 15 for supplying primary combustion air are coaxially provided on the side of the peripheral wall of the vaporization cylinder 4. The blower 3 is communicated with the primary air passage 16, while the fuel nozzle 14 is communicated with the oil tank 19 through the fuel supply pipe 17 and the fuel pump 18.
Reference numeral 20 is a cartridge tank for supplying liquid fuel to the oil tank 19.

Reference numeral 21 denotes an earth plate arranged on the outer periphery of the upper end portion of the vaporizing cylinder 4, and this earth plate 21 has an annular standing wall 21A facing the flame hole 12 at the outer peripheral edge thereof. The height is substantially equal to the height of the canopy 8B of the burner head 8. The detection portion of the frame rod 22 for detecting the flame F is located inside the standing wall 21A.

Reference numerals 23 and 23 denote flame holes 1 of the burner head 8.
2 is a plurality of (6 in the embodiment) heat recovery projections projectingly provided on the upper end 4A of the vaporization cylinder 4 and these heat recovery projections 23, 23 are shown in FIG. As shown, each has a cylindrical shape with a diameter T of about 6 to 8 mm and a height H.
Is set to approximately 8 to 10 mm, and approximately 25 to 3 which are substantially equal to each other in the circumferential direction of the upper end portion 4A of the vaporizing cylinder 4 which is annular.
It is provided with a large interval S of 5 mm, and is formed integrally with the vaporization cylinder 4. Here, all the heat recovery projections 23 are opposed to the flame holes 12 with the tops up, so that efficient heat recovery is performed.

Reference numeral 24 is an ignition electrode for igniting a mixture of vaporized fuel and combustion air ejected from the flame hole 12, and the discharge portion 24A at the tip of the ignition electrode 24 is, as shown in FIGS. Of the plurality of heat recovery protrusions 23, 23, the heat recovery protrusion 23 is laterally opposed to the heat recovery protrusion 23 at a distance V of about 2 to 3 mm. As shown in FIG. 4, the spark discharge from the discharge part 24A is blown to the heat recovery projection 23.

In the above-mentioned structure, when the vaporization cylinder 4 is heated to a predetermined temperature by energizing the heater 5, the blower 3 and the fuel pump 18 are operated, liquid fuel is supplied from the fuel nozzle 14 and air is supplied from the air nozzle 15. Combustion primary air is supplied to the vaporization chamber 6. Here, the liquid fuel ejected from the fuel nozzle 14 contacts the vaporization surface and is vaporized, and the mixture of the vaporized gas and the combustion primary air enters the burner head 8 through the passage of the diaphragm plate 7. Eject from the flame hole 12. Then, this air-fuel mixture is ignited by the spark discharge blown from the discharge part 24A of the ignition electrode 24 to the heat recovery projection 12, forms a flame F, and starts combustion. Then, when the temperature of the vaporization cylinder 4 is maintained at a high temperature by the combustion heat, the energization to the heater 5 is stopped, but the combustion is continued.

Here, when the combustion is strong combustion, the flame F formed on the side of the flame hole 12 becomes large and the high temperature portion of the flame F separates from the flame hole 12, but the high temperature portion of this flame F is A plurality of heat recovery projections 23 protruding from the upper end 4A of the vaporization cylinder 4,
Since each 23 is wrapped and heated, not only the contact area with the flame F increases but also the heat recovery projection 2
The heat of No. 3 is transferred to the vaporization cylinder 4 well, and even in the case of strong combustion where it is difficult to recover heat, the amount of heat recovery can be dramatically increased compared to the conventional case, and the vaporization cylinder 4 can be heated at about 260 to 350 ° C. The temperature suitable for vaporizing liquid fuel (kerosene) can be maintained.

On the other hand, when the combustion is weak, the flame F becomes small and approaches the respective flame holes 12, 12, so that the head main body 8A and the upper end portion 4A of the vaporization cylinder 4 are sufficiently heated by the flame F contacted with the flame. As a result, the vaporizing cylinder 4 can be heated and maintained at a temperature suitable for vaporizing the liquid fuel.

Therefore, the range of temperature change of the vaporizing cylinder 4 can be reduced, the combustion is stabilized over a wide range from the strong combustion to the weak combustion, the flame current can be stabilized, and the CO generation amount can be reduced, and the heat recovery can be achieved. By reducing the flame temperature due to the heat recovery action of the projecting projection 23, nitrogen oxides can be reduced and the combustion range can be greatly expanded.

Further, the discharge part 24 at the tip of the ignition electrode 24 is
The discharge part 24A is located opposite to the heat recovery protrusion 23 with a distance V of about 2 to 3 mm between the heat recovery protrusion 23 and the heat recovery protrusion 23.
Since the spark discharge from the electric field is blown to the heat recovery projection 23, the sparks flying from the discharge section 24A to the heat recovery projection 23 generate a mixed air flow ejected from the flame hole 12 as shown in FIG. It will always lie down and can make wide contact with the mixed air flow. This air-fuel mixture has a thick part and a thin part of the air-fuel mixture, but the wide contact of the spark with the air-fuel mixture increases the probability of contact between the dark part of the air-fuel mixture, which is in the flammable state, and the spark, and in a short time. It can be surely ignited. Therefore, it is possible to significantly improve the ignition performance without fear of causing an ignition mistake and taking too long time to ignite, and suppressing the outflow of unburned gas at the time of ignition and reducing the generation of a bad smell at the time of ignition. ..

Further, in the above-mentioned embodiment, the heat recovery projections 23, 23 are formed by aluminum die-casting in the vaporization cylinder 4
Since it is integrally molded with, the heat recovery projection 23 can be provided on the vaporization cylinder 4 without requiring a troublesome work such as cutting work, and can be manufactured very easily.

Further, since the plurality of heat recovery projections 23, 23 are provided with a space S between each other, the height H of the heat recovery projections 23 can be changed and the size of the diameter T can be changed. By appropriately setting the conditions for heat recovery, such as changing the number or increasing or decreasing the number, it is possible to easily adjust the heat recovery amount during strong combustion at the time of design.

[0021]

EFFECTS OF THE INVENTION Since the present invention is constituted as described above, the temperature of the vaporization section is always kept in an optimum state, the combustion is stable over a wide range from strong combustion to weak combustion, and the combustion width is wide. Moreover, a liquid fuel combustion device having excellent combustion characteristics can be obtained. Further, since the discharge part of the ignition electrode is located on the side of the heat recovery protrusion, the discharge spark can be widely contacted with the mixed air flow, the ignition performance is improved, and the foul odor during ignition can be reduced.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part of a liquid fuel combustion apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an overall configuration of the liquid fuel combustion apparatus, similarly.

FIG. 3 is a plan view of the same main part.

FIG. 4 is an enlarged plan view of an essential part of FIG.

FIG. 5 is a perspective view of the vaporizer tube alone.

[Explanation of symbols]

 4 vaporization cylinder 4A upper end of vaporization cylinder 8 burner head 11 peripheral wall (circumferential wall portion) 12 flame hole 23 heat recovery projection 24 ignition electrode 24A discharge part

Claims (1)

Claim: What is claimed is: 1. A vaporization cylinder into which liquid fuel and combustion air are supplied, a burner head provided at an upper portion of the vaporization cylinder and having a flame hole in a peripheral wall portion, and ejected from the flame hole. And a plurality of heat recovery projections facing the flame holes are provided at the upper end of the vaporization cylinder, and the discharge part of the ignition electrode is located on the side of the heat recovery projection. A liquid fuel combustion device characterized by being located at.