JP3123849B2 - 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 a liquid fuel combustion apparatus mainly used for an oil fan heater or the like, and more particularly to a liquid fuel combustion apparatus which detects the presence or absence of a flame or a decrease in oxygen concentration by means of a frame rod.

[0002]

2. Description of the Related Art A liquid fuel combustion apparatus used for a main oil fan heater or the like takes in indoor air as combustion air and discharges combustion gas into the room. In this case, the oxygen concentration in the room decreases, resulting in oxygen deficiency, incomplete combustion, and an increase in the amount of generated carbon monoxide, or a very dangerous state. Therefore, in recent years, as shown in, for example, Japanese Utility Model Publication No. Sho 63-22521, the presence or absence of a flame and a decrease in oxygen concentration are detected by a flame rod, and when the oxygen concentration falls below a reference value, a safety device is operated to activate combustion. It is known to stop the operation.

FIG. 3 shows the structure of a conventional liquid fuel combustion apparatus. A burner 1 has a vaporizing cylinder 2 made of aluminum die cast into which liquid fuel and combustion air are supplied, and an upper part of the vaporizing cylinder 2. And a heat-resistant metal burner having a burner head 4 provided with a plurality of flame holes 3 in a peripheral wall portion, and an upright wall 5A facing the flame holes 3 and having a base mounted on the outer peripheral portion of the upper end of the vaporizing cylinder 2. A ring 5 is provided, and a frame rod 6 is provided opposite to the flame hole 3 and serves as one electrode for flowing a flame ion current.

The safety device detects a change in the ionic current of the flame flowing between the frame rod 6 and the vaporizing cylinder 2 and detects a change in the ionic current of the flame when the oxygen concentration decreases and the flow of the ionic current of the flame rapidly decreases. In addition, the burner 1 is extinguished by stopping the operation of a fuel supply device such as a fuel pump, or an alarm lamp or a buzzer is driven to generate an alarm.

[0005]

The above-described liquid fuel combustion apparatus, for example, a petroleum fan heater takes in room air as combustion air and burns it. If you frequently use oil-containing hair sprays,
The silicon oil scatters and evaporates into the room, and the evaporated silicon oil mixes with the combustion air supplied to the burner 1, and this silicon oil is mixed with the vaporized fuel inside the vaporization cylinder 2 to form a flame of the burner head 4. It will squirt from the hole 3.

During the combustion, silicic acid (SiO ₂ ) is generated from the silicon oil, and the silicic acid bonds with the oxide film (alumina) on the inner surface of the burner ring 5, particularly the upright wall 5 A, on the earth side. Then, it accumulates on the inner surface of the upright wall 5A. Therefore, the resistance value of the burner ring 5 increases, the flow of the ion current of the flame rapidly decreases, and the safety device works unnecessarily, so that there is a problem that the oil fan heater cannot be operated normally. .

The present invention has been made in view of the above circumstances, and suppresses an increase in the resistance value on the ground side due to an external factor such as silicon oil contained in hair spray or the like or an impurity in fuel. And improve the reliability of the safety device.

[0008]

According to the present invention, a vaporizing cylinder,
A burner head having a flame hole in the peripheral wall and attached to the front end opening of the vaporizing cylinder; and
Burner ring with upright wall facing the hole and flame at the tip
Peripheral wall of the burner head so that the detection part faces the flame hole
Aluminum located between the burner ring and the upright wall of the burner ring
Frame made of iron-chromium-based heat-resistant metal material containing
And a rod, and wherein the flame rod detects the current of the flame. The upright wall of the burner ring has a smaller height than a material of the frame rod.
Iron-chromium heat-resistant metal material with low luminium content
The formed earth rod is located near the frame rod.
And the ground rod is exposed to flame.
At least partly with the peripheral wall of the burner head
This is a configuration arranged between the upright wall of the burner ring .

[0009]

With this configuration, the earth rod provided on the burner ring has a smaller heat capacity than the burner ring, and is thus heated to a higher temperature than the burner ring. For this reason, cracks and pits are likely to occur on the surface of the earth rod.For example, even if an insulating film is formed on the surface of the earth rod or burner ring by silicon contained in hair spray or the like, the crack generated on the surface of the earth rod The pits and pits form a new conductive portion, and a current flows through the grounding rod and the burner ring through the conductive portion, so that an increase in the resistance value on the ground side can be suppressed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In the drawing, reference numeral 10 denotes a burner. The burner 10 is made of aluminum die-cast, and has a bottomed cylindrical vaporizing cylinder 12 in which an electric heater 11 such as a sheathed heater is buried in a peripheral wall, and an upper part in the vaporizing cylinder 12. And a burner head 14 fitted and mounted on the front end opening of the vaporizing cylinder 12 above the throttle plate 13.
A horizontal portion is fixed to the upper end of the vaporizing cylinder 12 and comprises a burner ring 15 made of a heat-resistant metal disposed on the outer peripheral wall of the burner head 14. The burner head 14 has a large number of through holes 16, 16 in the bottom wall. And a large number of flame holes 17 are provided on the peripheral wall. 18 is the vaporization cylinder 1
2 is a bottomed cylindrical burner case in which the vaporizing cylinder 12 is accommodated and fixed inside, and a frame rod 19 and an ignition rod 20 are fixedly supported on an upper end flange portion 18A of the burner case 18. I have. 21 is the vaporization cylinder 1
A primary air passage 22 for feeding primary air for combustion from a blower (not shown) into the inside 2, and a secondary air 22 for feeding secondary air for combustion from the blower into a space between the vaporizing cylinder 12 and the burner case 18. It is a passage.

The frame rod 19 has a diameter of about 2.9.
It is made of an iron-chromium-based heat-resistant metal material (FCHW) containing about 4.5 to 6% of aluminum having a thickness of 0.2 mm, and a flame detecting portion 19A at the tip thereof is bent downward to face the flame hole 17. It is located in the position to do.

Reference numeral 23 denotes a fuel nozzle provided concentrically with the primary air passage 21 and having a front end portion facing the inside of the vaporizing cylinder 12. The fuel nozzle 23 is a fuel pump (not shown) such as an electromagnetic pump. The liquid fuel (kerosene) fed from the nozzle is jetted and supplied into the vaporization cylinder 12.

The burner ring 15 has an upright wall 15A facing the flame hole 17, and a base of an earth rod 24 bent in a substantially U-shape by spot welding is attached to the upright wall 15A. The earth rod 24
Is made of an iron-chromium-based heat-resistant metal material (FCHW) containing about 2 to 4% of aluminum having a diameter of about 3.5 to 4 mm, and its tip portion 24A has a flame similar to the flame detection portion 19A of the frame rod 19. By facing the position facing the hole 17, it is exposed to the flame F formed in the flame hole 17 at the time of combustion.

In the above-described configuration, when the temperature of the vaporizing cylinder 12 rises to a temperature at which the liquid fuel can be vaporized by energizing the electric heater 11, the blower and the fuel pump (both not shown) are operated, and the liquid fuel is discharged from the fuel nozzle 23. Further, primary air for combustion taken in from the room is supplied from the primary air passage 21 into the vaporization cylinder 12. Here, the liquid fuel supplied into the vaporization cylinder 12 contacts the vaporization surface and is vaporized. The mixture of the vaporized gas and the primary air for combustion is supplied to the passage of the throttle plate 13 and the through holes 16, 16. Through the burner head 14 and blows out from each of the flame holes 17. The jetted air-fuel mixture is ignited by a spark discharge generated between the tip of the ignition rod 20 and the burner head 14 and starts burning. A flame F directed to the side or obliquely upward is formed in each of the flame holes 17. At this time, the flame detecting portion 19A of the frame rod 19 and the tip portion 24A of the earth rod 24 are connected to the flame F.
Will be exposed to

Thus, the flame ion current flows through the frame rod 19, and the presence of the flame F and a decrease in the oxygen concentration are detected by the flow of the ion current. And the safety device is
A change in the ionic current of the flame flowing through the flame rod 19 is detected. When the oxygen concentration decreases and the flow of the ionic current of the flame sharply decreases, the operation of the fuel pump is stopped to extinguish the burner 10 or an alarm. Drive a lamp or buzzer to generate an alarm.

According to the present embodiment, the refractory metal of the burner ring 15 to the distal end outer peripheral portion of the vaporizing tube 12 is provided, off in diameter upright wall 15A of the burner ring 15 of about 3.5~4mm
An earth rod 24 made of iron-chromium heat-resistant metal material (FCHW) having a lower aluminum content than the material of the frame rod is attached, and a tip portion 24A of the earth rod 24 is attached.
At a position facing the flame hole 17 so as to be exposed to the flame F formed in the flame hole 17 during combustion.
At the position facing the earth rod,
Frame rods containing aluminum
The earth rod 24 is formed of a heat-resistant metal material of an iron-chromium system. Since the earth rod 24 has a smaller heat capacity than the burner ring 15, it is heated to a higher temperature than the burner ring 15.

Therefore, when exposed to the flame F of the earth rod 24,
Cracks and pits occur on the surface of the tip 24A
-Silicone (S) from silicon oil contained in spray etc.
iO _Two) Is generated, and this silicic acid is
The surface of the tip portion 24A and the upright wall 15A of the burner ring 15
If an insulating coating adheres to the inner surface of the
Cracks or pits generated on the surface of the tip 24A of the rod 24
Is a new conductive part, and the earth lock
The flame ion current flows through the gate 24 and the burner ring 15.
As a result, the resistance of the earth side suddenly increases due to silicon.
Increase is suppressed and safety devices are activated unnecessarily to
Prevents malfunctions that can prevent the operation of the fan heater.
Can be stopped.

In the above embodiment, the ground rod 2
4, the shape is not limited to this. For example, the lower end is fixed to the inner surface of the upright wall 15A of the burner ring 15 by spot welding, and the upper end is formed on the burner head 14 side. And the upper end is flame F
The both ends may be fixed to the inner surface of the upright wall 15A of the burner ring 15 by spot welding, and the intermediate portion may be extended to a position exposed to the flame F. Any shape may be used as long as it has a portion that contacts the burner ring 15 and a portion that is exposed to the flame F.

[0019]

Since the present invention is configured as described above, it is possible to suppress a rapid increase in the resistance value on the ground side due to external factors such as silicon contained in hair spray and the like and impurities in fuel. Thus, it is possible to provide a liquid fuel combustion apparatus which is resistant to disturbances and is excellent in safety and reliability.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an entire configuration of a liquid fuel combustion apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a main part of the same.

FIG. 3 is a sectional view of the entire configuration of a conventional liquid fuel combustion device.

[Explanation of symbols]

 12 Vaporization tube 14 Burner head 15 Burner ring 17 Flame hole 19 Flame rod 24 Earth rod F Flame

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F23N 5/12

Claims (1)

(57) [Claims] 1. A vaporizing cylinder, a burner head having a flame hole in a peripheral wall and mounted in an opening at a distal end of the vaporizing cylinder, and a burner head outside the vaporizing cylinder.
A bar attached to the periphery and having an upright wall facing the flame hole
Cornering and the flame detector at the tip
Between the peripheral wall of the sea urchin head and the upright wall of the burner ring
Of iron-chromium containing aluminum
And a flame rod made of a heat metal material, in a liquid fuel combustion apparatus adapted to detect the current of the flame by the flame rod, the upright wall of the burner ring, frame
Iron with less aluminum content than mud rod material
Chromium-ground rod made of a refractory metal material of the
Provided near the frame rod , and
The earth rod is at least partially exposed to the flame
Between the peripheral wall of the burner head and the upright wall of the burner ring
A liquid fuel combustion device, being arranged .