As a kind of mechanical and electrical integration equipment with high degree of automation, burner can be divided into five systems from its functions: air supply system, ignition system, monitoring system, fuel system and electric control system.

I. air supply system

The function of the air supply system is to send air with certain wind speed and air volume into the combustion chamber. Its main components are: shell, fan motor, fan impeller, air gun fire pipe, air door controller, air door baffle and diffusion plate.

1. Shell: it is the main part of the installation bracket of each part of the burner and the fresh air inlet channel. From the appearance, it can be divided into two types: box type and gun type. Most of the high-power burners adopt split shell, generally gun type. The shell is generally made of high strength light alloy castings. (as shown in Figure 1-1) the observation hole on the top cover has the function of observing the flame

2. Fan motor: it mainly provides power for the operation of fan impeller and high-pressure oil pump. Some burners also use separate motor to provide power for oil pump. Some small power burners use single-phase motor, the power is relatively small, most burners use three-phase motor, the motor can make the burners work normally only according to the determined direction of rotation. It has the function of driving oil pump and air vane. The motor is generally 2800 rpm

3. Fan impeller: generate enough air pressure through high-speed rotation to overcome furnace resistance and chimney resistance, and blow enough air into the combustion chamber to meet the needs of combustion. It is composed of cylindrical wheels equipped with blades with a certain angle of inclination, and its material is generally high-strength light alloy steel. All qualified fan impellers have good dynamic balance performance.

4. Air gun fire pipe: it plays the role of guiding the air flow and stabilizing the air pressure, and it is also an integral part of the air inlet channel. Generally, it has a coat flange connected with the furnace mouth. Its component material is generally alloy steel with high strength and high temperature resistance. It can adjust the wind speed.

5. Damper controller: it is a kind of driving device, which controls the rotation of damper plate through mechanical linkage. Generally, there are three kinds of controllers: manual control, hydraulic drive controller and servo motor drive controller. The former works stably and is not easy to cause faults, while the latter controls accurately and the air volume changes smoothly.

6. Damper: the main function is to adjust the size of the air inlet channel to control the size of the air inlet. Its composition material is alloy, and alloy baffle plate has a variety of combination forms such as single piece, double piece and three piece. (Fig. 1-6)

7. Diffusion disk: also known as flame stabilizing disk, its special structure can produce rotating air flow, which is conducive to the full mixing of air and fuel, as well as regulating the secondary air volume. (Fig. 1-7)

II. Ignition system

The function of ignition system is to ignite the mixture of air and fuel. Its main components are: ignition transformer, ignition electrode, high-voltage electric fire cable.

8. Ignition transformer: it is divided into electronic type and mechanical (inductive) type. It is a conversion element that produces high-voltage output. Its output voltage is generally 25kV, 26kv and 27KV, and the output current is generally 15-30ma. There are EDI, Danfoss, domestic Danfoss and Feida. The difference between oil engine and gas engine is that oil engine generally has two heads and gas engine generally has one head. It can be divided into electronic type and mechanical type (as shown in Figure 1-8)

9. Ignition electrode: convert high-voltage electric energy into light energy and heat energy in the form of arc discharge to ignite fuel. Generally, there are two kinds of styles: single style and split style. Generally, the ignition pin is made of stainless steel, which can withstand high temperature of 800 degrees, while we use nickel chromium wire, which can withstand high temperature of 1500 degrees. Pay attention that the ignition rod cannot contact with the metal

10. Electric fire high-voltage cable: its function is to transmit electric energy. It can withstand 1.5 million volts.

III. monitoring system

The function of the monitoring system is to ensure the safe operation of the burner. Its main components are flame monitor, pressure monitor, external temperature monitor, etc.

11. Flame monitor: its main function is to monitor the formation of flame and generate signals to report to the program controller. There are three kinds of flame detector: photoresist, UV eye and ionization electrode. (Fig. 1-11)

A. photoresistor: it is mainly used on light oil and heavy oil burners. Its function and working principle are: photoresistor is connected with a flame relay with three contacts. The resistance of photoresistor changes with the brightness of light received by the device. The brighter the light received, the lower the resistance. When the voltage applied to both ends of photoresistor is fixed, the higher the current in the circuit will be. When the current reaches At a certain value, the flame relay is activated, so that the burner continues to work downward. When the photoresist does not feel enough light, the flame relay does not work and the burner will stop working. Photoresistors are not suitable for gas burners.

B. ionization electrode: mostly used on gas burner. The programmable controller supplies power to the ionization electrode. If there is no flame, the power supply on the electrode will stop. If there is flame, the gas will be ionized by its own high temperature. The ion current flows between the electrode, the flame and the combustion head. The ion current will be rectified into direct current, and it will reach the flame relay through the shell of the grounded burner to make it work, so as to ensure that the subsequent work of the burner can be carried out smoothly. If the ionization electrode is grounded, the generated current is AC rather than DC, the flame relay will not work and the program controller will lock. In addition, the instability of the flame in the ionization zone will also cause the burner to open when the flame still exists, which may be due to the improper air gas ratio, which can be solved by adjusting the air or gas quantity, or the uneven distribution of the air gas on the combustion head, which can be solved by adjusting the position of the combustion head.

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