JPH0674841U - Low NOx burner flame detection structure - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] In a burner that swirls and burns air and fuel in the combustion cylinder, the fuel and air are mixed well and a stable flame is generated while the flame light is emitted. Send the flame detector securely. [Structure] The flame detection device 11 is provided on the upper surface of the wind box 15 which is just above the combustion cylinder inner cylinder 2, and a hole for light collection is opened in the nozzle side surface of the combustion cylinder inner cylinder vertically lowered from the installation location. A lighting pipe 13 is attached between the hole 9 and the flame detection device, and the light of the flame generated in the combustion cylinder is sent to the flame detection device through the lighting pipe.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a burner that swirls and burns air and fuel in a combustion cylinder.

[0002]

[Prior art]

 A conventional burner injects primary air and secondary air into the fuel flow from parallel or oblique directions, and mixes and burns them.Therefore, when trying to obtain good combustion, the amount of air is reduced. It is necessary to increase the amount, and there is a problem that the amount of NOx generated increases. Therefore, the nozzle side has a small hole for fuel spraying, the opposite side is open, and the four side faces are in a row parallel to the central axis of the combustion cylinder at a position close to one corner side. A rectangular parallelepiped combustion cylinder inner cylinder with small holes at the same position on each surface, and a square ring at the tip of the combustion cylinder, swirl and mix the fuel and air in the inner cylinder to burn and burn. Combustion with good mixing was performed by mixing the flame emitted from the cylinder with the secondary air (Japanese Patent Laid-Open No. 2-267407).

If no flame is generated during fuel supply, it is very dangerous. If no flame is present, fuel supply is stopped and abnormal stop is performed. In the case of a burner that burns in the inner cylinder, the flame is generated in the inner cylinder, so the light reaching the flame detector installed on the original side of the combustion cylinder is much less than in a normal burner, and the precision It is necessary to frequently perform maintenance management using a different flame detection device, but it is still easy to cause false detection, and abnormal stoppage occurred even during normal combustion.

[0004]

[Problems to be solved by the present invention]

 The problem to be solved by the present invention is to prevent the malfunction of the flame detection device by reliably sending the flame light to the flame detection device while mixing the fuel and air well and generating a stable flame. It is in.

[0005]

[Means for Solving the Problems]

 A flame detector is installed on the upper surface of the wind box, which is directly above the inner cylinder of the combustion cylinder, and a hole for lighting is opened in the nozzle side surface of the inner cylinder of the combustion cylinder that is vertically lowered from the installation location. A light tube is attached between the two to allow the light of the flame generated in the combustion cylinder to be sent to the flame detection device through the lighting tube.

[0006]

[Action]

 If a hole is made in the nozzle side surface, more light will reach the flame detection device, but since the amount of air flowing in the same direction as the fuel injection direction will increase, the flame will lift and the air from the side of the inner cylinder that creates the swirling air flow Due to the reduced flow, the swirling force is weakened and the mixture of fuel and air is reduced. A hole is opened on the side of the nozzle of the combustion cylinder inner tube, and the combustion cylinder inner cylinder and the flame detection device are connected by a lighting tube, and when light is passed through the tube, the light emitted from the lighting hole does not diffuse and flame detection is performed. Light can be sent directly to the device. Since the pipe is attached to cover the lighting hole, air does not enter the inner cylinder through the lighting hole, so that flame does not lift and good combustion can be performed and soot adhesion can be prevented.

[0007]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. The combustion cylinder tip ring (12) which is drawn in a square shape is connected to one end of the cylindrical combustion cylinder outer cylinder (1), and the other end is connected to the blower (10). A rectangular parallelepiped combustion cylinder inner cylinder (2) is provided in front of the spray nozzle (7) on the tip side of the combustion cylinder. The spray nozzle (7) is connected to the oil pump (3) by the oil feed pipe (8), and the fuel pressurized by the oil pump is sprayed by the spray nozzle and passes through the spray hole (4) of the combustion cylinder inner cylinder and the combustion cylinder. Enter the inner cylinder (6). The combustion air sent out by the blower passes from the wind box (15) through the combustion cylinder outer cylinder, enters the combustion cylinder inner cylinder through the air holes (5) formed on the four sides of the combustion cylinder inner cylinder, and then inside the cylinder. Form a swirling flow. A flame detection device (11) for detecting the presence or absence of a flame is provided on the upper surface of the wind box directly above the combustion inner cylinder by utilizing the fact that the electric resistance changes depending on the brightness. A lighting hole (9) is opened at a position vertically lowered from the flame detection device in the combustion cylinder inner cylinder. A lighting tube (13) having the same inner diameter as the lighting hole is provided between the lighting hole and the flame detecting device, and a heat-resistant glass (14) is provided between the flame detecting device and the lighting tube. When combustion starts, the flame generated in the combustion cylinder produces intense light and heat. Light and heat pass from the lighting hole through the lighting tube, and the heat is blocked by the heat-resistant glass, and only light reaches the flame detection device. The light is sent to the flame detection device without being scattered, and the flame detection device detects that the flame is generated by the light. The presence or absence of flame is sent to the combustion control device (16), and when the flame actually disappears, the oil pump is stopped immediately.

[0008]

[Effect of device]

 Combustion inside the combustion cylinder The combustion inside the cylinder can be kept very good, and since the light of the flame surely reaches the flame detection device, malfunction of the flame detection device can be prevented. Since reliable flame detection can be performed, it is possible to prevent an abnormal stop that occurred because the flame could not be detected when the flame was normally generated.

[0009]

[Brief description of drawings]

1 is a cross-sectional perspective view of an embodiment of the present invention 1 combustion cylinder outer cylinder 2 combustion cylinder inner cylinder 3 oil pump 4 spray hole 5 air hole 6 combustion cylinder inner cylinder 7 spray nozzle 8 oil pipe 9 light collection hole 10 blower 11 Flame Detecting Device 12 Combustion Cylinder Tip Ring 13 Lighting Tube 14 Heat-Resistant Glass 15 Windbox 16 Combustion Control Device

Claims (1)

[Scope of utility model registration request] 1. A rectangular parallelepiped combustion cylinder inner cylinder is provided at the tip of a nozzle in the combustion cylinder outer cylinder, a fuel spray hole is provided on the nozzle side surface, and the opposite surface is opened, On each of the remaining four side faces parallel to the central axis, a plurality of small holes parallel to the central axis of the combustion cylinder are arranged in rows close to one corner side of the side surface, and at the tip of the outer cylinder of the combustion cylinder. In a burner equipped with a combustion cylinder outer cylinder tip ring that is opened so that the inside is parallel to each side of the tip of the combustion cylinder, install a flame detection device on the upper surface of the wind box just above the combustion cylinder. A low NOx burner characterized in that a hole for lighting is provided on the nozzle side surface of the combustion cylinder inner cylinder vertically provided from the flame detection device, and a lighting pipe is attached between the lighting hole and the flame detection device. Flame detection structure.