Physical And Numerical Simulation On Top And Bottom Combined Blown Technology In70t Vanadium Extraction Converter

According to the similarity theory, based on70t vanadium extraction converter in a factory, the study uses the converter model in1:8to do many experiments. They have been done to study the influence for top-bottom blowing vanadium extraction converter on bath mixing time of the arrangement of the bottom of the gas component and the bottom blowing flow. The study investigates their influence on the slag splashing of different heights of converter lining at the same time. The experiments are based on numerical simulation to study the flow field inside the pool. The conclusions are as follows:(1) By comparing the mixing time of7bottom blowing layout schemes, the study find that the best bottom blowing layout scheme is:four bottom guns are unsymmetrically arranged at the two rings of bottom diameter are0.42D and0.51D, the line between four gun of two corresponding diameter has the angle of60°.(2) Regardless of the flow and top-blowing lance conditions, with the bottom blowing flow rate increases, the mixing time were tested as a decreasing trend. Therefore, the best water model experiment bottom-blown flow is0.069Nm3/h. Binding field conditions, taking a flow rate of bottom-blown of0.054Nm3/h.(3) The best experimental program is:top-blown flow is24.84Nm3/h, the gun position is212.5mm, bottom blowing flow is0.054Nm3/h in early slag splashing; top-blown flow is23.18Nm3/h, the gun position is212.5mm, bottom blow flow is0.054Nm3/h in the late slag splashing.(4) Surface height of cavity of mathematical model is36±3mm, the relative difference with physical model is10%, radius of cavity of mathematical model is75±2mm, the relative difference with physical model is16.7%, mixing time of mathematical model is78s, mixing time of physical model is70s, the relative difference is10.3%, the inosculation between them is better. (5) With the lance height from1000mm to900mm, surface height of cavity is from190mm to285mm, radius of cavity of mathematical model is from311.5mm to330.5mm in the numerical model to site; with the lance height from900mm to800mm, surface height of cavity is from285mm to299mm, radius of cavity of mathematical model is from330.5mm to307.5mm in the numerical model to site and bottom gas flow rate has no obvious effect on surface of cavity, so site should use lance range of800mm-900mm considering cavity on blowing effect.(6) To low lance height, the molten steel flow velocity in the pool is slower and more stable at high lance height and the "dead zone" is bigger at high lance height, so with the conditions allowing low lance height is benefit to blowing.(7) Compared with pool of top blowing, flow velocity of the liquid steel in molten pool has increased, especially in "dead zone" and "circumfluence zone". So improve the bottom blowing layout schemes is particularly important.(8) Unsymmetrical bottom blowing tuyeres layout leads to "circumfluence" at bottom and is benefit to blowing of all pool, special to the central region, which provides a scientific basis for superiority of A4bottom blowing layout.