Classification and principle of fuel atomization nozzle
1、 Mechanical atomization.
The mechanical atomization nozzle uses high oil pressure to spray oil from the nozzle at high speed to realize atomization. The fuel with a certain pressure and temperature enters the tangential groove through the oil inlet hole and uniform oil groove to obtain a higher speed, and then enters the swirl chamber. The oil produces strong centrifugal rotation in the swirl chamber, which causes the groove pulsation, and sprays out from the nozzle, forming a hollow conical membrane. Due to the diffusion of oil through the nozzle under turbulent flow and the centrifugal effect, the surface tension is crushed into many small oil particles, thus achieving the purpose of atomization.
2、 Rotor atomization.
The working principle of the rotor atomization is that the fuel oil is sent to the high-speed rotating cup-shaped device of 3000~5000r/min through the hollow shaft. Under the action of centrifugal force, the oil sticks to the inner wall of the rotor, forms a thin oil film, flies out along the rotor mouth, and atomizes into thin oil particles. At the same time, the fan blades installed on the same shaft blow out the wind through the guide vane along the rotor mouth, and the direction of the wind rotation is opposite to the direction of the oil droplets, further atomizing the oil droplets.
3、 Steam atomization.
The principle of steam atomization is to use high-speed steam to take oil out and break it into oil particles by spraying, and then use steam expansion and oil heating in the furnace to further break the oil particles into thinner oil mist.
According to the mixing position of oil and steam, steam atomizing nozzle can be divided into internal mixing nozzle and external mixing nozzle. The mixing of steam and oil in the nozzle is internal mixing, and the mixing of steam and oil outside the nozzle is external mixing. Steam atomization has good quality, fine and uniform oil particles, and can be used for various fuel oils.
4、 Air atomization.
Oil is sprayed out of the nozzle at a low pressure, and high-speed air (about 80m/s) is used to spray around the oil to atomize the oil. According to the different air pressure used, the air atomizing nozzle is divided into three types: high pressure, medium pressure and low pressure. In order to obtain high pressure air, high and medium pressure air atomizing nozzles must use air compressors, so they are rarely used in boilers, while low pressure air atomizing nozzles are mainly used in boilers.