Study On Atomization Characteristics And Structure Of Spray Nozzle For Release Agent

Release agent spraying is one of the key steps of pretreatment of die casting in the former process, film quality is largely dependent on the atomization quality of release agent. The purpose of this paper is to optimize the structure of the nozzle, research carried out under this background, and influences of working parameters on the spray performance is discussed. Through the research above, some useful methods and suggestions are put forward in the nozzle design. The main work of this thesis is summarized as following:1) The paper establishes geometric and mathematical models of spraying gas flow and gas-liquid two-phase flow, and operating parameters of air-assisted atomizer on the effect of spray characteristics and the particle size distribution on the downstream section of nozzle outlet are discussed. Meanwhile, it analyzes main factors affecting the spray characteristics.2) The paper sets up a mathematic model according to the breakup of liquid film process, and put forward that the main factors that affect the derivation of atomization characteristics of spray are gas-liquid relative velocity and gas-liquid angle. Then structure optimization of nozzle is done referred to the Victoria Brzezinski curve. Results of optimisation are consistent with the theoretic analysis.3) At last a test bench is built to study flow characteristics and atomization characteristics of nozzles with different gas-liquid angle and indent distance in order to verify the simulation results. The #2-2 nozzle, whose gas-liquid angle is 20 degree and indent distance is 1 mm, is equipped with more flow stable characteristics, spray cone angle increasing by about 4 degrees, atomization ability increasing by early 10%. The experiment results indicate that the structure optimization in this paper is reasonable.