Abstract: In order to improve the RH refining efficiency, the physical simulation research on the bottom blowing position and flow of RH refining ladle were carried out for the 120 t RH refining unit of a steel plant. Firstly, the more appropriate process parameters were determined, the lifting gas flow was 1 408 L/min and the depth of impregnation tube was 540 mm. Then, three different positions of bottom blowing holes were set relative to the positions of the riser and the down comer, which were that the single hole was directly below the riser, and the connecting line between the double hole and the riser and the downcomer was vertical and parallel. Through the study of three indexes of mixing time, circulating flow and flow velocity, it was found that the refining effect of the single hole was better than that of the double hole, the refining effect of double hole vertical position was better than that of parallel position, so it was recommended to adopt single hole bottom blowing process.

Key words: RH refining, bottom blowing, physical simulation, mixing time, circulating flow, flow velocity