JPH06213432A - Combustion apparatus - Google Patents

Abstract

PURPOSE:To prevent an unnecessary operation of a safety device due to an external cause such as silicone oil contained in a hair spray, etc. CONSTITUTION:A combustion apparatus comprises a flame rod 19 oppositely to a flame port 17 of a burner 10 for burning mixed gas of fuel and the air to detect presence/absence of a flame F and a decrease in oxygen concentration, and an auxiliary rod 24 of a material in which heat resistance is deteriorated as compared with that of the rod 19 at a position to be exposed with the frame F of the rod 19. With such a structure, a crack, pitting corrosion occurring on a surface of the rod 24 becomes a new conductive part to further satisfactorily feed ionic current of the flame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device mainly used for petroleum fan heaters and the like, and more particularly to a combustion device in which a flame rod detects the presence or absence of a flame and a decrease in oxygen concentration.

[0002]

2. Description of the Related Art A combustion apparatus used for this type of 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, oxygen deficiency occurs, incomplete combustion occurs, and the amount of carbon monoxide generated increases. Therefore, in recent years, for example, as shown in Japanese Utility Model Publication No. Sho 63-22521, the presence or absence of a flame or a decrease in oxygen concentration is detected by a frame rod, and when the oxygen concentration is lower than a reference value, a safety device is activated to perform combustion. It is known to stop.

FIG. 5 shows the structure of a conventional combustion apparatus. A burner 1 is equipped with a vaporization tube 2 into which liquid fuel and combustion air are supplied, and a burner 1 which is mounted on the vaporization tube 2 and has a peripheral wall portion. A burner head 4 having a plurality of flame holes 3 is provided, and a frame rod 5 is provided so as to face the flame holes 3. Then, the safety device detects a change in the ionic current of the flame flowing through the frame rod 5, and when the oxygen concentration decreases and the flow of the ionic current of the flame sharply decreases, the operation of the fuel supply device such as the fuel pump is activated. To extinguish the burner 1 by stopping the
An alarm lamp and a buzzer were driven to generate an alarm.

[0004]

By the way, since the above-mentioned combustion apparatus, for example, the oil fan heater, takes in the air in the room as combustion air and burns it, silicon oil is removed during the heating operation of the oil fan heater. When the contained hair spray is frequently used, the silicone oil is scattered and evaporated in the room, and the evaporated silicone oil is mixed with the combustion air supplied to the burner 1, and the silicone oil is vaporized in a vaporizing cylinder. 2 is mixed with vaporized fuel inside and is ejected from the flame holes 3 of the burner head 4.

During combustion, silicic acid (SiO ₂ ) is produced from the silicone oil, and this silicic acid combines with the oxide film (alumina) on the surface of the frame rod 5 and accumulates on the surface of the frame rod 5. To do. Therefore, the resistance value of the frame rod 5 is increased, the flow of the ion current of the flame is sharply reduced, the safety device is unnecessarily operated, and the oil fan heater cannot be normally operated. .

The present invention has been made in view of the above circumstances, and it is possible to prevent the safety device from unnecessarily operating due to external factors such as silicone oil contained in hair sprays and impurities in fuel. The purpose is to prevent.

[0007]

According to the present invention, a frame rod is provided so as to face a flame hole of a burner for burning a mixture of fuel and air, and the presence or absence of a flame and a decrease in oxygen concentration are detected by this frame rod. In the combustion device,
An auxiliary rod made of a material having heat resistance lower than that of the frame rod is attached to a portion of the frame rod exposed to the flame.

Further, in the present invention, a flame rod is provided facing the flame hole of the burner for burning the mixture of fuel and air, and the flame rod is used to detect the presence or absence of flame and the decrease in oxygen concentration. In the device, an auxiliary rod made of a material having a lower aluminum content than the frame rod is attached to a portion of the frame rod exposed to the flame.

[0009]

With this structure, since the auxiliary rod is slightly inferior in heat resistance strength to the frame rod, cracks and pitting easily occur on its surface. For example, silicon contained in hair spray etc. Even if an insulating coating is formed on the surface of the rod, cracks and pitting corrosion that have occurred on the surface of the auxiliary rod become a new conduction part, and the flame ion current flows through the auxiliary rod to the frame rod. It is possible to prevent the resistance value of the frame rod from rapidly increasing due to impurities in the fuel or fuel. The same applies to the second aspect.

Further, if the radial cross-sectional area of the auxiliary rod is made larger than the radial cross-sectional area of the frame rod, the surface area of the auxiliary rod is increased, and the conductive portion due to cracks or pitting can be increased.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings of FIGS. In FIG. 1, reference numeral 10 denotes a burner. This burner 10 has a bottomed cylindrical vaporization cylinder 12 in which an electric heater 11 such as a sheath heater is embedded in a peripheral wall, and a diaphragm plate 13 arranged in the upper part of the vaporization cylinder 12. And a burner head 14 fitted and mounted on the upper end opening of the vaporization cylinder 12 on the diaphragm plate 13, and a horizontal portion fixed to the upper end of the vaporization cylinder 12 and disposed on the outer periphery of the peripheral wall of the burner head 14. The burner head 14 is composed of a steel burner ring 15, and the burner head 14 has a large number of through holes 16 and 16 in its bottom wall and a large number of flame holes 17 and 17 in its peripheral wall.

Reference numeral 18 denotes a bottomed cylindrical burner case which is provided on the outer circumference of the vaporization cylinder 12 and accommodates and fixes the vaporization cylinder 12 therein.
A frame rod 19 and an ignition rod 20 are fixedly supported on A. Reference numeral 21 denotes a primary air passage for sending the primary air for combustion from a blower (not shown) into the vaporization cylinder 12 and 2
Reference numeral 2 is a secondary air passage for sending the combustion secondary air from the blower into the space between the vaporization cylinder 12 and the burner case 18.

Reference numeral 23 denotes a fuel nozzle which is provided concentrically with the primary air passage 21 and has its tip facing the inside of the vaporizing cylinder 12, and the fuel nozzle 23 is a fuel pump (not shown) such as an electromagnetic pump. The liquid fuel (kerosene) sent from is jetted and supplied into the vaporization cylinder 12.

An auxiliary rod 24 is fixed to the frame rod 19 by spot welding or the like at a tip portion 19A facing the flame hole 17 of the burner head 14 and exposed to the flame F during combustion. The length of the auxiliary rod 24 is set to about 12 to 14 mm, and as shown in FIG. 2, the lower end of the auxiliary rod 24 is separated from the tip end surface of the frame rod 19 by 3 to 5 mm, and the flame hole 17 is formed.
The auxiliary rod 24 is fixed to the opposite side thereof, and as shown in FIG. 3, the radial sectional area of the auxiliary rod 24 is larger than the radial sectional area of the frame rod 19. That is, the frame rod 1
9 has a diameter of about 2.9 mm, while the auxiliary rod 24 has a shape in which a part of the rod having a diameter of about 3.5 to 4 mm in the longitudinal direction is shaved and a portion in contact with the frame rod 19 is made flat. There is.

Further, the frame rod 19 is made of an iron-chromium refractory metal material (FCHW) containing aluminum in an amount of about 4.5 to 6%, while the auxiliary rod 24 is used.
Is an iron-chromium heat-resistant metal material (FCH containing less than 2% to 4% of aluminum and less than the frame rod 19).
W), the auxiliary rod 24 is made of a material having slightly lower heat resistance than the frame rod 19.

In the above structure, when the vaporization cylinder 12 is heated to the vaporizable temperature of the liquid fuel by energizing the electric heater 11, the blower and the fuel pump (both not shown) are activated and liquid fuel is discharged from the fuel nozzle 23. Further, the primary air for combustion taken 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 is vaporized by contacting the vaporization surface, and the mixture of the vaporized gas and the primary air for combustion is passed through the passage of the diaphragm plate 13 and the through holes 16, 16. And enters the burner head 14 and ejects from each flame hole 17, 17. The jetted air-fuel mixture is ignited by spark discharge generated between the tip of the ignition rod 20 and the burner head 14 to start combustion, and the flames directed to the flame holes 17 and 17 laterally or obliquely upward. F is formed, and at this time, the tip end portion 19A of the frame rod 19 and the auxiliary rod 24 are exposed to the flame F.

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

According to this embodiment, the tip end portion 19A of the frame rod 19 is opposed to the flame hole 17 of the burner head 14, and the frame rod 19 is located at the portion of the tip end portion 19A of the frame rod 19 exposed to the flame F. Since the auxiliary rod 24 made of a material having a lower aluminum content and poorer heat resistance is fixed, the auxiliary rod 24 is exposed to the flame F and cracks or pitting occurs on the surface thereof.

Therefore, silicic acid (SiO ₂ ) is generated from the silicone oil contained in the hair spray and the like, and the silicic acid adheres to the tip portion 19A of the frame rod 19 and the surface of the auxiliary rod 24 to form an insulating coating. In this case, the cracks and pitting corrosion that have occurred on the surface of the auxiliary rod 24 become new conduction parts, and the frame rod 1 passes through this auxiliary rod 24.
The ion current of the flame can be made to flow to 9, and the resistance value of the frame rod 19 can be prevented from rapidly increasing due to the silicone oil, so that the safety device operates unnecessarily and the oil fan heater cannot be operated. It is possible to prevent such problems.

Further, since the auxiliary rod 24 may be fixed to the anti-flame hole side of the conventionally used frame rod 19 by spot welding or the like, the conventional problems can be prevented with a simple and inexpensive structure.

Further, since the radial cross-sectional area of the auxiliary rod 24 is made larger than the radial cross-sectional area of the frame rod 19, the surface area of the auxiliary rod 24 is increased, and the surface of the auxiliary rod 24 is correspondingly increased. The number of conductive parts due to cracks and pitting that are formed is increased, and the ionic current of the flame can be made to flow better.

FIG. 4 shows another embodiment. In this other embodiment, the earth rod 25 made of the same material as the auxiliary rod 24 is fixed to the vertical wall 15A of the burner ring 15. The tip portion 25A of the earth rod 25 extending inside the vertical wall 15A is opposed to the tip portion 19A of the frame rod 19 described above, and the other structures are the same as in the one embodiment. In the other embodiment, the auxiliary rod 24 and the earth rod, which have a lower aluminum content and a lower heat resistance than both the frame rod 19 and the tip end 19A of the frame rod 19 and the burner ring 15, are used. Since the respective 25 are provided, it is possible to more reliably prevent the problem that the safety device is unnecessarily operated due to the silicone oil contained in the hair spray and the like, and it is possible to reduce the influence on the swing of the flame F.

Although the liquid fuel combustion apparatus has been described in each of the above embodiments, a gas combustion apparatus may be used.

[0024]

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it is possible to prevent the resistance value of the flame rod from rapidly increasing due to external factors such as silicon contained in hair spray and the like, and impurities in the fuel. Therefore, it is possible to prevent a defect that the safety device operates unnecessarily, improve reliability while maintaining safety, and prevent a conventional defect with a simple and inexpensive structure.

Further, as in the above-described embodiment, if the radial cross-sectional area of the auxiliary rod is made larger than the radial cross-sectional area of the frame rod, the conduction caused by cracks or pitting corrosion formed on the surface of the auxiliary rod 24. The number of parts can be further increased, and the ionic current of the flame can be better passed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of the overall configuration of a combustion apparatus showing an embodiment of the present invention.

FIG. 2 is a side view of the same frame rod.

FIG. 3 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 4 is a cross-sectional view of the overall configuration of a combustion device showing another embodiment of the present invention.

FIG. 5 is a cross-sectional view of the overall configuration of a conventional combustion device.

[Explanation of symbols]

 10 Burner 17 Flame Hole 19 Frame Rod 24 Auxiliary Rod F Flame

Claims (2)

[Claims] 1. A combustion apparatus in which a flame rod is provided facing a flame hole of a burner for burning a mixture of fuel and air, and the flame rod detects the presence or absence of a flame and a decrease in oxygen concentration. A combustion apparatus, wherein an auxiliary rod made of a material having heat resistance lower than that of the frame rod is attached to a portion of the frame rod exposed to the flame. 2. A combustion apparatus in which a flame rod is provided facing a flame hole of a burner that burns a mixture of fuel and air, and the flame rod detects the presence or absence of a flame and a decrease in oxygen concentration. A combustion device, wherein an auxiliary rod made of a material having a lower aluminum content than the frame rod is attached to a portion of the frame rod exposed to the flame.