Surface Flow Control
Recently, optimum control of mixing in current refining processes accompanied by bottom gas injection has become increasingly important because the metallurgical reactions in the bath proceed at different rates and in different sites with a lapse of time. The intensity of mixing is commonly represented by the mixing time T m [1-8]. Measuring the mixing time in the bath of real metallurgical reactors is difficult. Therefore, it is usually predicted on the basis of water model experiments using electric conductivity sensor and dilute aqueous KCl solution as tracer. The mixing time is known to be influenced by operating variables, such as the bath diameter D, bath depth H L, the location of bottom nozzle, and gas flow rate Q g . However, only Q g can be easily controlled during processing. Even the effect of the gas flow rate Q g on the mixing time is relatively weak.
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