Experimental validation of a model predicting the evaporation rate of zinc in a transferred arc.

摘要

A mathematical model has been developed to allow optimization and scale up of a metal evaporator as a function of plasma operating parameters such as composition and flow rate of the plasma gas, arc current, arc length as well as wall and crucible temperatures. The system argon-zinc has been chosen to validate and calibrate the output of the model simulations with experimental measurements. The plasma gas used in the system was argon, and the metal to be evaporated was zinc. The relatively low boiling point of zinc allowed more precise measurements of the boundary and operation conditions being examined. Experimental measurements of the evaporation rate of zinc at atmospheric pressure and steady state were compared with the predictions of the computational model over a broad range of plasma operating conditions and temperature boundary conditions. Measurements of temperature at different locations in the crucible were taken to obtain the crucible temperature profile; the range of current used was between 100 and 275 A; the plasma gas flow rate covered a range from 10.7 to 27.9 slpm while the arc length was varied from 3.0 to 5.2 cm. (Abstract shortened by UMI.).