论文部分内容阅读
采用Fluent软件建立超声雾化喷嘴气流场的数值模拟模型,研究入口压力、导液管孔径与伸出长度对超声雾化喷嘴气雾化性能的影响,并采用超声雾化法制备GCr15轴承钢粉末,验证入口压力对粉末粒度的影响。结果表明:导液管伸出长度Δh=1 mm时,入口压力越大,越有利于提高雾化效果;在Δh=2 mm或Δh=3 mm条件下,当入口压力小于2.0 MPa时,增大入口压力可有效提高雾化性能,而当入口压力超过2.0 MPa后,增大入口压力对提高雾化性能效果有限。导液管的孔径对气流场结构影响较小,主要通过影响金属液的质量流率来影响雾化效果。雾化实验结果表明,在Δh=1 mm、导液管孔径d=4.5 mm时,2.8 MPa入口压力下的雾化性能优于2.0 MPa与1.2 MPa下的雾化性能,获得的GCr15轴承钢粉末平均粒径最小,整体球形度最佳,该实验结果与数值模拟研究结果一致。
Fluent software was used to establish the numerical simulation model of the flow field of the ultrasonic atomizing nozzle. The effects of inlet pressure, the diameter of the liquid pipe and the protruding length on the gas atomization performance of the ultrasonic atomizing nozzle were studied. The GCr15 bearing steel powder was prepared by ultrasonic atomization , To verify the impact of inlet pressure on the particle size of the powder. The results show that when the extension length of the catheter is Δh = 1 mm, the larger the inlet pressure is, the better the atomization effect is. When Δh = 2 mm or Δh = 3 mm, when the inlet pressure is less than 2.0 MPa, Large inlet pressure can effectively improve the atomization performance, and when the inlet pressure exceeds 2.0 MPa, increasing the inlet pressure has a limited effect on improving the atomization performance. The pore size of the catheter has little effect on the structure of the gas flow field, which affects the atomization effect mainly by affecting the mass flow rate of the liquid metal. The results of atomization show that the atomization performance under inlet pressure of 2.8 MPa is better than that of 2.0 MPa and 1.2 MPa when Δh = 1 mm and the diameter of the liquid pipe is 4.5 mm. The obtained GCr15 bearing steel powder The average particle size is the smallest and the overall sphericity is the best. The experimental results are consistent with the numerical simulation results.