Design and evaluation of a Laval-type supersonic atomizer for low-pressure gas atomization of molten metals
来源期刊：International Journal of Minerals Metallurgy and Materials2014年第6期
论文作者：Chao-run Si Xian-jie Zhang Jun-biao Wang Yu-jun Li
文章页码：627 - 635
摘 要：A Laval-type supersonic gas atomizer was designed for low-pressure gas atomization of molten metals. The principal design objectives were to produce small-particle uniform powders at lower operating pressures by improving the gas inlet and outlet structures and optimizing structural parameters. A computational fluid flow model was developed to study the flow field characteristics of the designed atomizer. Simulation results show that the maximum gas velocity in the atomization zone can reach 440 m·s–1; this value is independent of the atomization gas pressure P0 when P0 > 0.7 MPa. When P0 = 1.1 MPa, the aspiration pressure at the tip of the delivery tube reaches a minimum, indicating that the atomizer can attain the best atomization efficiency at a relatively low atomization pressure. In addition, atomization experiments with pure tin at P0 = 1.0 MPa and with 7055 Al alloy at P0 = 0.8 and 0.4 MPa were conducted to evaluate the atomization capability of the designed atomizer. Nearly spherical powders were obtained with the mass median diameters of 28.6, 43.4, and 63.5 μm, respectively. Compared with commonly used atomizers, the designed Laval-type atomizer has a better low-pressure gas atomization capability.
Chao-run Si1，Xian-jie Zhang1，Jun-biao Wang1，Yu-jun Li1,2
1. Shannxi Engineering Research Center for Digital Manufacturing Technology, Northwestern Polytechnical University2. Institute of Applied Mechanics, RWTH Aachen University
摘 要：A Laval-type supersonic gas atomizer was designed for low-pressure gas atomization of molten metals. The principal design objectives were to produce small-particle uniform powders at lower operating pressures by improving the gas inlet and outlet structures and optimizing structural parameters. A computational fluid flow model was developed to study the flow field characteristics of the designed atomizer. Simulation results show that the maximum gas velocity in the atomization zone can reach 440 m·s–1; this value is independent of the atomization gas pressure P0 when P0 > 0.7 MPa. When P0 = 1.1 MPa, the aspiration pressure at the tip of the delivery tube reaches a minimum, indicating that the atomizer can attain the best atomization efficiency at a relatively low atomization pressure. In addition, atomization experiments with pure tin at P0 = 1.0 MPa and with 7055 Al alloy at P0 = 0.8 and 0.4 MPa were conducted to evaluate the atomization capability of the designed atomizer. Nearly spherical powders were obtained with the mass median diameters of 28.6, 43.4, and 63.5 μm, respectively. Compared with commonly used atomizers, the designed Laval-type atomizer has a better low-pressure gas atomization capability.
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