The working principle of the air atomizing nozzle is different from that of the mechanical nozzle. It uses the spraying effect of compressed air to atomize the fuel.
The air atomizing nozzle is a two-fluid nozzle (air and liquid), and the atomizing nozzle is a one-fluid nozzle (liquid). There are many types and different internal structures. Therefore, it can avoid the disadvantages of poor atomization at low oil pressure inherent in mechanical nozzles and the limitation of oil supply pressure for oil site adjustment.
In this type of fuel injection nozzle, most of the compressed air is injected into the combustion space through the air velocity at a velocity of about 300m/s. The inner cavity of the fuel is mixed with fuel and shot out from the nozzle. This two-layer air interflow solution can ensure good fuel atomization.
The fuel quantity adjustment of the air injector is also achieved by changing the fuel supply pressure, but because the atomization is based on air spray instead of the fuel injection speed, the fuel injection pressure is required to be lower, as long as 1.0- under full load. 1.5MPa (gauge pressure) is sufficient, and its atomization quality is controlled by adjusting the pressure and flow of the atomizing air.
The test shows that the consumption rate of atomizing air is generally 4% of the theoretical combustion air site of the fuel, and the ratio of the pressure of atomizing air to the pressure in the combustion chamber is about 1.8. The adjustment range of fuel flow can reach 7%-100%. When working at low pressure load, because the ratio of atomized air volume to fuel oil is larger, the atomization quality is better. This kind of fuel injector has high reliability, even if it is applied to dirty heavy fuel. Blockage occurs, and because of the low flow rate of the fuel in the oil passage, it is not easy to wear, and the atomization quality is the most stable. Therefore, it has outstanding advantages over mechanical fuel injectors for burning heavy fuels.