直流电弧热等离子体制备纳米镍粉过程的数值模拟

Numerical simulation of nano-nickel powder preparing process by DC arc thermal plasma

摘要:

研究镍粉颗粒在直流电弧热等离子体中的汽化过程可以为优化热等离子体纳米镍粉的制备工艺提供参考。本文通过对磁流体力学方程和颗粒热动力学方程的耦合求解，研究了原料粒径、工作气流量及送粉速率等参数对镍粉颗粒在直流热等离子体中的运动行为及加热过程的影响效应。研究表明，粒径较小的颗粒在高温区内停留的时间更长，从等离子体中吸收到的热量更多，因此能够在更短的时间内被加热到完全汽化；降低工作气流量及送粉速率均可以增加镍粉颗粒从热等离子体中获得的能量，这对于提升颗粒的汽化率，改善最终制备的纳米镍粉品质是有益的。

Abstract:

Study on vaporization process of nickel powder particles inside direct current thermal plasma can provide theoretical guidelines for improving preparation process of nickel nanopowder. In this paper, The effects of particle size, working gas flow rate and feeder rate on the nickel particle behavior in thermal plasma are investigated by coupled solution of the magnetohydrodynamic equations and particle thermodynamics equations. The research shows that small particles can be heated to complete vaporization in a shorter time owing to longer residence time in the high temperature region; Decrease of working gas flow rate and powder feeder rate can increase the energy of nickel particle get from plasma, thus Improving the quality of the final prepared nano nickel powder.