Mixing behavior in the RH degasser with bottom gas injection

Shortening the mixing time of melt can enhance the decarburization rate during the Rheinsahl-Heraeus (RH) degassing process. In this study, a numerical method has been employed to investigate and compare the mixing behavior in the RH degasser without and with simultaneous bottom injection of gas (one porous plug, and three porous plugs, respectively). The locations of plug are discussed and optimized to yield the shortest mixing time of melt. Then, industrial trials are preliminarily conducted to study the effect of bottom injection on decarburization rate during the RH degassing. Simulation results show that gas injection through one plug at the ladle bottom, under the up-snorkel, can shorten the melt mixing time remarkably by increasing the melt circulation rate and optimizing the flow pattern in the RH degasser, and the addition of other two plugs at appropriate locations can further reduce the mixing time. Trial results show that a lower [C] content in steel can be obtained in a shorter time for the RH degasser with bottom injection. (C) 2016 Elsevier Ltd. All rights reserved.