| There are many advantages for the top and bottom blowing converter. For example, the balance between molten steel and slag is easily achieved, and the oxidizability of molten steel and slag is decreased. It improves the molten bath stirring and makes the time of the molten steel temperature and ingredient mixing time shorter. It also can increase the capability of desulfurization and produce good economic efficiency, etc. This paper is based on the actual production data of the top and bottom blowing converter of Bayuquan steel plant, Ansteel. The influence of the top and bottom blowing converter on the carbon oxygen equilibrium, the composition of molten steel, the consumption of metal materials is studied. The results show that: the carbon and oxygen equilibrium of top and bottom converter is lower than that of top blowing converter, and at the beginning of furnace service life, the combined blowing effect is better than that at the later of furnace service life; the proper number of bottom gun is two to three; it is benefit to the melting of low carbon steel for the top and bottom combined blown converter, which is reached about 80% for the steel of final carbon belonging0.03%-0.06%; the final [P] is lower, Mn is higher and the effect on the [S] is not evident; the index of metal materials of combined blown converter is better than that of top blown converter and the economical benefit is evident.Bottom blowing is the key for the combined blowing. Therefore, on the base of production data, the effect of furnace life, bottom lance type and bottom lance position on the bottom blowing is studied in this paper. The results showed that: the key factors to increase the combined blowing are controlling the bottom lance part melting and furnace thickness fluctuation and the adopted main method is bottom lance hot replace on line; average life can reflect the management and technical criteria, economical furnace life is about 5000 in Ba Yuquan steel on thinking about combined blowing effect and furnace line maintenance cost; critical thickness of converter bottom is about 500 mm. The metallurgical effect of circumferential bottom lance is better than that of single pipe. The erosion of furnace line of position 5# and 6# bottom lance locating near to trunnion is slow and that of position 3# and 4# is fast. |
