JP2980533B2 - Premix gas burner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a premixed gas burner, and more particularly to a premixed gas burner for preventing a pilot burner from igniting.

[0002]

2. Description of the Related Art A burner is ignited by first igniting a pilot burner by generating a spark with a spark rod and igniting a main burner by using the flame of the pilot burner. Is not provided separately from the main burner.
As described in -57022, a pilot gas nozzle, a frame rod and a spark rod are provided in the vicinity of the pilot gas nozzle in the wind box, a part of the main burner is set as a pilot burner, and the pilot burner is ignited. There has been proposed a premixed gas burner that detects the presence or absence of a flame by detecting the current flowing in the flame with a frame rod provided in the gas burner.

[0003] However, when the pilot burner is ignited, normal ignition may not be performed and non-ignition may occur. In addition, if the position of the pilot flame and the electrode of the frame rod are displaced, no flame is detected. In some cases, it was judged abnormal.

[0004]

An object of the present invention is to prevent a premixed gas burner from igniting a pilot burner.

[0005]

A premixed gas burner in which a premixed gas is introduced into a wind box of a burner and burns downstream of a combustion plate provided at the end of the wind box. A pilot gas nozzle, a flame rod and a spark rod at positions close to the pilot gas nozzle are provided, and in a premixed gas burner in which a part of the main burner is a pilot burner, the gas injection direction of the pilot gas nozzle is concentrated in the direction of the flame rod and the spark rod. By doing so, ignition of the pilot burner and detection of the flame are reliably performed. In addition, a means is provided to prevent a large amount of air from being sent to the pilot burner portion or to provide a means for reducing the amount of combustion air sent into the wind box, and by performing control to reduce the amount of air blown when the pilot burner is ignited. Improve the performance.

[0006]

In the conventional pilot gas nozzle, the gas injection ports are provided radially, and the fuel gas spreads over the entire pilot burner portion. Although the flame was not detected due to the deviation from the part, the fuel gas injected from the pilot gas nozzle was concentrated in the direction of the flame rod and the spark rod, and the fuel gas ratio near the spark rod was increased. After ignition, the flame is burned in the flame rod portion, so that the presence or absence of a flame can be reliably detected. Also, when the amount of air sent to near the pilot gas nozzle is reduced,
The fuel gas ratio is relatively increased, and the ignitability is improved.

[0007]

An embodiment of the present invention will be described. A mixing chamber 3 for mixing the combustion air sent from the blower 1 and the fuel gas sent from the main gas supply pipe 2 is provided on the base side of the premixing burner, and the mixing chamber 3 is connected to a wind box 4 of the burner. Have been. A baffle plate 5 for diffusing the premixed gas sent from the mixing chamber 3 into the wind box 4 is provided near the connection portion with the mixing chamber 3 in the wind box 4, and a rectifying plate made of punching metal further downstream. 6. At the tip of the burner, a combustion plate 7 having a large number of holes is provided.

A pilot gas nozzle 9 is provided between the current plate 6 and the combustion plate 7 near the wall surface 8 of the wind box, and a partition plate 10 is provided between the current plate 6 and the combustion plate 7 so as to surround the pilot gas nozzle 9. And a flame rod 12 for generating a spark downstream of the combustion plate 7 of the pilot burner section and a flame rod 12 for detecting a flame downstream of the combustion plate 7 of the pilot burner section.

The combustion control of the burner is performed by a control device 14. The control device 14 includes a blower 1, a main solenoid valve 15 provided in a main gas supply pipe 2, and a pilot gas supply pipe for supplying fuel gas to a pilot gas nozzle. 16
It is connected to a pilot solenoid valve 17, a spark rod 11, and a frame rod 12 provided therein.

When igniting the pilot burner,
The controller 14 sends the combustion air to the mixing chamber 3 by operating the blower 1, but the main solenoid valve 15 is not opened and the fuel gas is not supplied, so that only the combustion air is sent into the wind box 4. It is. The combustion air that has entered the wind box 4 hits the baffle plate 5 and is diffused into the wind box 4, passes through a hole formed in the current plate 6, and a part of the combustion air is surrounded by the partition plate 10. Enter the pilot burner section. The gas injection ports 13 of the pilot gas nozzle 9 are directed toward the spark rod 11 and the frame rod 12, and the fuel gas is mixed with the combustion air and passes through the holes of the combustion plate 7. Since the fuel gas is injected toward the spark rod 11, the premixed gas in the vicinity of the spark rod 11 has a high gas concentration, and a spark is generated by the spark rod 11 to easily form a pilot flame. . Further, since the fuel gas is also injected toward the frame rod 12, the flame burns near the frame rod 12 and the flame rod 1
No. 2 can reliably detect the flame. The combustion of the main burner is performed by supplying a fuel gas from a main gas supply pipe 2, and the fuel gas is mixed with combustion air in a mixing chamber 3, enters a wind box 4 as a premixed gas, and is supplied to a wind box 4. Combustion takes place over the entire surface.

FIG. 2 shows the diameter of the hole in the current plate 6 and FIG.
FIG. 4 is a cross-sectional view taken along the line AA when the density of the holes of FIG.
It is BB sectional drawing when the shape of the baffle plate 5 is changed. When the hole for introducing the combustion air to the pilot burner portion surrounded by the partition plate 10 of the rectifier plate 6 is made smaller than the diameter of the other portion, or is made smaller than the density of the other portion, the hole is introduced into the pilot burner portion. Combustion air volume is reduced. The amount of air introduced into the pilot burner can also be reduced by widening the baffle plate 5 toward the pilot burner. By reducing the amount of air in the pilot burner, the gas concentration is increased to prevent misfiring.

Further, by reducing the air supply amount at the time of ignition, it is possible to prevent non-ignition. The motor that drives the blower 1 is a DC motor whose rotation speed can be changed by changing the voltage, and a circuit that reduces the voltage supplied to the motor of the blower 1 is provided in the control device 14.
When the pilot burner is ignited by emitting sparks from the air blower 1, the amount of air sent from the blower 1 is reduced by lowering the voltage supplied to the blower 1, and the gas ratio in the pilot burner is increased. Ignition prevents misfiring. After ignition, the voltage supplied to the blower 1 is returned to normal, and when burning the main burner, a normal amount of air is supplied.

[0013]

According to the present invention, it is possible to prevent the pilot burner from being ignited.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line AA in another embodiment.

FIG. 4 is a sectional view taken along line BB of FIG. 1;

FIG. 5 is a perspective view showing an outline in one embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 blower 2 main gas supply pipe 3 mixing chamber 4 wind box 5 baffle plate 6 rectifier plate 7 combustion plate 8 wind box wall surface 9 pilot gas nozzle 10 partition plate 11 spark rod 12 frame rod 13 gas injection port 14 control device 15 main electromagnetic valve 16 pilot Gas supply piping 17 Pilot solenoid valve

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F23D 14/14-14/18 F23N 1/02 F23N 3/08 F23Q 9/00

Claims (3)

(57) [Claims] 1. A premixed gas burner for introducing combustion air and fuel gas into a wind box of a burner and performing combustion downstream of a combustion plate provided at a tip of the wind box on a downstream side in a flow direction of the combustion air. A pilot gas nozzle is provided near the wall surface in the wind box, a part of the main burner is provided as a pilot burner part by providing a partition plate so as to surround the pilot gas nozzle, and a spark rod that generates a spark downstream of the combustion plate of the pilot burner part. In a premixed gas burner in which a flame rod that detects a flame on the downstream side of the combustion plate of the pilot burner section is provided in the pilot burner section so as to be parallel to the combustion air flow direction, the gas injection direction from the pilot gas nozzle is Flame rod and spark rod A premix-type gas burner, wherein a gas injection port of a pilot gas nozzle is provided so as to be in each direction. 2. A premixed gas burner for introducing combustion air and fuel gas into a wind box of a burner and performing combustion downstream of a combustion plate provided at a tip of the wind box on a downstream side in a flow direction of the combustion air. A pilot gas nozzle is provided near the wall surface in the wind box, a part of the main burner is provided as a pilot burner part by providing a partition plate so as to surround the pilot gas nozzle, and a spark rod that generates a spark downstream of the combustion plate of the pilot burner part. In a premixed gas burner provided with a frame rod for detecting a flame downstream of a combustion plate in a pilot burner portion, a baffle plate perpendicular to a combustion air flow direction is provided in a wind box, and the baffle plate is provided in the wind box. By widening from the center to the pilot burner side A premixed gas burner characterized in that the amount of air sent to the pilot burner section is reduced. 3. A premixed gas burner for introducing combustion air and fuel gas into a wind box of a burner and performing combustion downstream of a combustion plate provided at a tip of the wind box on a downstream side in a combustion air flow direction. A pilot gas nozzle is provided near the wall surface in the wind box, a part of the main burner is provided as a pilot burner part by providing a partition plate so as to surround the pilot gas nozzle, and a spark rod that generates a spark downstream of the combustion plate of the pilot burner part. In a premixed gas burner equipped with a flame rod that detects a flame on the downstream side of the combustion plate of the pilot burner, a number of holes that allow combustion air to pass through a plane perpendicular to the combustion air flow direction are provided in the wind box. An open current plate is provided, and the current plate is located in front of the pilot burner. The minute hole is made smaller than the diameter of the hole in the other part or is made smaller than the density of the other part to reduce the amount of air sent to the pilot burner part. Mixed gas burner.