The construction and principle of the burner can vary according to their type and use. The following are the structures and working principles of several common buraks:
1. Process burner: the process nozzle usually adopts a three-flow casing structure, with the central tube conveying oxygen, the middle casing conveying coal slurry, and the outer gap conveying oxygen again. A cooling coil is usually provided at the nozzle. The working principle is that the oxygen of the ring gap of the central cavity and the outer tube is mixed with the coal slurry at the nozzle. Using the impact force of oxygen, the coal slurry is sprayed into the gasifier in the form of high-speed fog to achieve the effect of atomized coal slurry.
2. Gas burner: the working principle of the gas burner is that the blower motor rotates and drives the fan blade to rotate. Due to the principle of centrifugal force, the air is sent out by the rotating impeller at high speed. The air is fully mixed in the mixing room with the incoming fuel (gas or fuel oil). When the gas fuel is used, the gas passes through the control valve into the mixing chamber and mixed with the air. The mixed fuel must be ignited by an ignition system before it is fired into the furnace. The firing mouth is equipped with a booster transformer. When the primary transformer is connected into the power supply, the transformer secondary generates high voltage, which is sent to the ignition electrode through the high voltage cable, and the ignition electrode breaks through the air for discharge, forming an arc and lighting into the mixed fuel.
3, Venturi burner: Venturi burner usually uses natural gas or liquefied petroleum gas as fuel. Gas enters from the entrance, and the air is brought in by the high-speed gas airflow. The gas is mixed with the air in the mixing tube, and then enters a section of the expansion tube. The mixed gas comes out of the expansion pipe into the stainless steel (ceramic) nozzle, where the gas mixture is quickly heated to the ignition temperature and burned. The advantages of Venturi burner include the low air excess coefficient of gas complete combustion, low pollutant emissions, premixing of gas and air, high combustion temperature, energy saving and environmental protection design, and the structure to avoid tempering and flameout phenomenon.
4. The regenerative burner: the working principle of the regenerative nozzle is two burner with heat transfer function, and the other burner is used as the exhaust outlet, and the heat of the flue gas is absorbed to the heat exchanger used as the burning nozzle, so as to achieve the effect of heat accumulation.
5. Flat flame burner: the structure and principle of the flat flame burner is that the gas and air entering the burner nozzle rotate strongly under the action of the cyclone, unfold along the surface of the furnace wall perpendicular to the center line of the burning mouth brick, and are burned out in the first floor space close to the furnace wall, forming a garden plate flame. After using the flat flame burner, because the heat radiation capacity is strengthened, the temperature field is uniform, so the heating speed is fast, the metal oxidation burning rate is low, which has a significant effect on the uniform heating of steel, rapid heating and fuel saving.
In conclusion, different types of burner mouths have different structures and working principles, and they are designed to meet specific industrial needs, such as improving combustion efficiency, reducing pollution emissions, optimizing the temperature distribution in the furnace, etc.