JP2931425B2 - Liquid fuel combustion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil fan heater,
The present invention relates to a vaporization type liquid fuel combustion device used for 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 liquid fuel combustion apparatus is provided on the upper outer periphery of a vaporizing cylinder having a burner head having a flame hole in a peripheral wall. A ground plate having an annular upright wall facing the flame hole is provided, and the spread of the flame formed from the flame hole toward the side is suppressed as much as possible by this ground plate. There is known one that is prevented from being heated to a temperature higher than the temperature.

[0003]

By the way, in the above-mentioned vaporizing cylinder of the conventional apparatus, the heat generated by the combustion is recovered by the upper surface part which is fogged by the flame, and the vaporizing part is kept in kerosene even if the power supply to the vaporizing heater is stopped. And the like, the temperature at which the liquid fuel vaporizes can be maintained, but the temperature varies by about 50 to 70 degrees depending on the combustion state (strong combustion and weak combustion). That is, in the strong combustion, the heat recovery amount decreases because the high temperature part of the flame moves away from the burner head, and conversely, in the weak combustion, the heat recovery amount increases because the flame approaches the burner head.

[0004] The preferred temperature of the vaporizing section is about 260-350.
It is said to be ° C. When the temperature is lower than 260 ° C., tar easily accumulates in the vaporizing section, and when the temperature is higher than 350 ° C., a phenomenon occurs in which the particulate unvaporized fuel flies in the vaporization chamber (splashing phenomenon). As a result, the flame was mixed with red fire.

[0005] Therefore, in the conventional apparatus, the amount of heat recovered to the vaporizing cylinder changes greatly depending on the combustion state, and the temperature difference due to the change in the amount of heat recovery causes the vaporized portion to cover a wide range from strong combustion to weak combustion. It is not possible to maintain a suitable temperature, and there is a problem that it is not possible to maintain good combustion when trying to expand the combustion width.

The present invention has been made in view of the above-mentioned facts, and has as its object to maintain the temperature of the vaporizing section in an optimum state over a wide range from strong combustion to weak combustion. .

[0007]

According to the present invention, a liquid fuel is used.
A cylindrical cylinder with a bottom that is heated and vaporized by mixing with secondary air, and a mixture that is disposed above the vaporizer and is vaporized by the vaporizer.
Numerous flame holes for ejecting gas to form a combustion flame
A burner head having a peripheral wall and a burner head
Shaped so as to be opposed to the flame hole by being sandwiched between
The formed annular upright wall, and the upright wall and the flame hole are provided.
Between the obtained peripheral wall, fuel configuration a plurality of heat recovery wall exists a gap to each other and disposed at a constant temperature of the vaporizing tube and the heat transfer relationship
It is a baking device .

[0008]

With this construction, the flame becomes small during weak combustion, and the flame approaches the burner hole of the burner head. Therefore, the burner head and the upper end of the vaporizing cylinder are sufficiently heated by the flame in contact with the flame. Can be heated and maintained at a temperature suitable for fuel vaporization.

Further, the flame becomes large during the strong combustion, and the high temperature portion of the flame separates from the flame hole portion. However, the heat recovery wall located between the upright wall and the burner head is heated in contact with the high temperature portion of the flame. Since the flame enters the space between the heat recovery walls, the contact area with the flame can be increased, and the heat recovery amount during strong combustion can be increased.

Here, since a plurality of heat recovery walls are provided at intervals from each other, heat recovery conditions such as the height of the heat recovery walls and the distance between adjacent heat recovery walls are appropriately set. Thus, the amount of heat recovery during strong combustion can be easily adjusted at the time of design or the like.

[0011]

1 and 2 show an embodiment of the present invention.
This will be described with reference to the drawings. In the drawing, reference numeral 1 denotes a bottomed cylindrical burner case to which combustion secondary air from a blower 3 is supplied via a secondary air passage 2, 4 is built in the burner case 1, and a sheath heater is provided on the upper peripheral wall thereof. Heater 5
Is a buried cylindrical vaporizing cylinder having a bottom.
Is made of aluminum die cast having good thermal conductivity, and a vaporization chamber 6 is formed inside.

An aperture plate 7 is provided in the upper part of the vaporizing cylinder 4, and a burner head 8 composed of a head main body 8A and a canopy 8B is provided on the upper end opening of the vaporizing cylinder 4 above the aperture plate 7. It is installed. Also, the head main body 8A is provided with a large number of ventilation holes 10, 10 in a bottom wall 9 thereof, and a large number of flame holes 12, 12 in a peripheral wall 11 thereof. Is omitted)
Is provided with a wire net 13.

A fuel nozzle 14 for supplying liquid fuel (kerosene) to the vaporizing chamber 6 and an air nozzle 15 for supplying primary combustion air are coaxially provided on the side of the peripheral wall of the vaporizing cylinder 4. The nozzle 15 is connected to the blower 3 via a primary air passage 16, while the fuel nozzle 14 is connected to the fuel supply passage 1.
7 and a fuel pump 18 communicate with an oil tank 19. Reference numeral 20 denotes a cartridge tank for replenishing the oil tank 19 with liquid fuel.

Reference numeral 21 denotes an earth plate disposed on the outer periphery of the upper end of the vaporizing cylinder 4. This earth plate 21 has an annular upright wall 21A facing the flame holes 12, 12 on the outer peripheral edge thereof. The height of 21A is changed to the canopy 8B of the burner head 8.
It is assumed to be approximately equal to the height of And the upright wall 21A
The detection part of the frame rod 22 for detecting the flame F is positioned inside the frame.

23, 23 are standing walls 21 of the earth plate 21
And a plurality (22 in the embodiment) provided at the upper end of the vaporizing cylinder 4 at a position substantially at the center between the A and the peripheral wall 11 of the head main body 8A.
The heat recovery walls 23, 23 are provided with an interval S of 2 to 6 mm (3 mm in the embodiment) mutually,
Its height is set to be substantially the same as or slightly lower than the upper edge of the flame hole 12, and is formed integrally with the vaporizing cylinder 4. Reference numeral 24 denotes an igniter for igniting a mixture of vaporized fuel and air ejected from the flame hole 12, and reference numeral 25 denotes a temperature detector for detecting the temperature of the peripheral wall of the vaporizing cylinder 4 which is a vaporizing unit.

In the above configuration, when the temperature of the vaporizing cylinder 4 rises to a predetermined temperature by energizing the heater 5, the blower 3 and the fuel pump 18 operate, and liquid fuel from the fuel nozzle 14 and liquid fuel from the air nozzle 15 Combustion air is in vaporization chamber 6
Supplied to Here, the fuel ejected from the fuel nozzle 15 contacts the vaporizing surface and is vaporized, and a mixture of the vaporized gas and the combustion air passes through the passage of the throttle plate 7 and enters the burner head 8, and the flame hole It gushes from 12. This air-fuel mixture is ignited by spark discharge from the igniter 24 to form a flame F and start burning. Then, when the temperature of the vaporizing cylinder 4 is maintained at a high temperature by the combustion heat, the power supply to the heater 5 is stopped.

In the case of strong combustion, the flame F formed on the side of the flame hole 12 is large, and the high-temperature portion of the flame F is separated from the flame hole 12. The heat recovery walls 23, 23 located between the upright wall 21 </ b> A and the peripheral wall 11 of the head main body 8 </ b> A are brought into contact with each other to heat them, and a flame is applied to each space S between the heat recovery walls 23, 23. Since F enters, not only the contact area with the flame F increases, but also the heat of each heat recovery wall 23, 23
And the heat recovery amount can be dramatically increased compared to the past, even during strong combustion where heat recovery is difficult.
The vaporizing cylinder 4 can be heated and maintained at a temperature of about 260 to 350 ° C. suitable for vaporizing liquid fuel (kerosene).

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 of the vaporizing cylinder 4 are sufficiently heated by the flame F which has come into contact with the flame. Thus, the vaporizing cylinder 4 can be heated and maintained at a temperature suitable for vaporizing the fuel.

Therefore, as described above, the temperature difference of the carburetor 4 from strong combustion to weak combustion can be reduced, and the combustion is stabilized over a wide range from strong combustion to weak combustion, thereby stabilizing the flame current. And the amount of CO generated is reduced, and the temperature of the flame F is reduced by the heat recovery action of the heat recovery walls 23, 23, whereby the generation of nitrogen oxides can be suppressed, and the combustion range can be greatly expanded. Is what you can do.

Further, since the heat recovery walls 23, 23 are provided in large numbers with an interval S therebetween, the height of the heat recovery wall 23 is set slightly lower than the upper edge of the flame hole 12. Alternatively, by appropriately setting the conditions for heat recovery, such as increasing or decreasing the distance S between the adjacent heat recovery walls 23, 23, the amount of heat recovery during strong combustion can be adjusted. Easy to do when designing.

Further, in the above embodiment, the heat recovery wall 23
Is set lower than the upright wall 21A of the ground plate 21, the flame F formed from the flame hole 12 toward the side is formed.
The spread of heat can be suppressed by both the heat recovery wall 23 and the earth plate 21, and the heating of the metal cylinder constituting the combustion chamber can be further suppressed, and the combustion chamber can be made more compact.

Although the heat recovery wall 23 is formed integrally with the vaporizing cylinder 4 in the above-described embodiment, it may be manufactured separately from the vaporizing cylinder 4 and attached to the vaporizing cylinder 4.

[0023]

According to the present invention, the temperature difference of the vaporizing cylinder from strong combustion to weak combustion is reduced so that the temperature of the vaporizing section is always kept at an optimum state. Thus, it is possible to provide a liquid fuel combustion apparatus in which combustion is performed stably over a wide range, the combustion range is wide, and the combustion characteristics are excellent.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a liquid fuel combustion apparatus according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of the vaporizing cylinder.

[Explanation of symbols]

 Reference Signs List 4 vaporization cylinder 8 burner head 11 peripheral wall (peripheral wall) 12 flame hole 21 ground plate 21A upright wall 23 heat recovery wall S interval

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F23D 11/40 F23D 11/44 F23D 11/10

Claims (1)

(57) [Claims] 1. Heating and vaporizing a liquid fuel mixed with primary air
A bottomed cylindrical vaporization tube which, disposed on top of the vaporizing tube
The gaseous mixture that has been vaporized in the vaporizer
Burner head having a large number of flame holes on its peripheral wall for forming
Before being interposed between the burner head and the combustion secondary air flow path.
An annular upright wall formed to face the flame hole;
Between the upright wall and a peripheral wall provided with the said burner ports of each other exists a <br/> gap plurality of heat recovery walls the vaporizing tube and the heat transfer relationship
A liquid fuel combustion apparatus, wherein the liquid fuel combustion apparatus is disposed while being kept .