Effect of a self-rotating oxygen lance system on mass transfer between slag and molten steel

To improve the efficiency of the steelmaking process,a system of self-rotating lance was designed,and corresponding cold simulation mechanism was developed.The influence of the self-rotating lance on the mass transfer rate between slag and molten steel was investigated by comparing this novel system with the traditional oxygen lance.The results show that the self-rotating lance can stably rotate with a gas jet as the power source.The mass transfer rate increases with an increase in the top and bottom blow flow rates and with a decline in the lance position.Approximately 13.7% of the top blow flow rate is converted to stirring energy,which is approximately twice that of the traditional oxygen lance,and the mass transfer rate can increase by over 30%.Furthermore,the impact energy can be concentrated at different depths of the molten bath by adjusting the rotational speed.With the same energy density,the mass transfer rate produced by the self-rotating lance is higher;however,the influence of the energy density on the mass transfer rate is low when the rotational speed is 30-50 r/min.

An experimental study on RH vacuum chamber with a weir

A new Ruhrstahl-Heraeus(RH)equipment with a weir added to the vacuum chamber was designed to help improve refining efficiency of low-carbon steel production.The flow characteristics of the new RH equipment and a traditional RH equipment were evaluated and compared through water modeling experiments and an optimized calculation model.In the water experiments,the mixing time,the residence time and the circulation flow rates were measured,and the flow simulating molten steel in the vacuum was photographed.The results show that the decarburization efficiency in the new RH equipment is much improved.The mixing time is equal to or less than that of the latter when the gas flow rate is higher than 2.33 m^(3)/h.The proportion of the piston flow increases by at least 40%,and the proportion of the well-mixed flow decreases from greater than 40%to less than 20%.The effective flow rate of the new RH equipment increases greatly in the piston flow zone and the total lag flow zone based on the residence time distribution experiment.In conclusion,when a weir is added to a RH vacuum chamber,the effective circulation flow increases significantly,and the decarburization rate KC of molten steel at low-carbon stage is improved.