Centrifugal Molecular Distillation Rotating Film Flow Model And Device Design

Molecular distillation is a sort of advanced liquid-liquid separating technique, widely applied for petroleum chemical engineering,medication,light industry,oiL foodstuff etc.. This new technique can concentrate and refine the materials which have high molecular weight,high boiling point,high viscidity and organic compounds whose thermal stability is sensitive. The research about the technique of molecular distillation is lacking in china, especially basic process and theory study are less absent,, In the wake of study hotspot, the paper develops exploring study for molecular distillation together with model investigation and equipment design. This paper includes four aspects: 1 Analyzing and studying process parameters and structure parameters about centrifugal molecular distillation still summarizing their common rules, providing theory direction for the still's process optimizing and structure amelioration. 2 On the evaporation turnplate, flowing and evaporation characters of liquid film are the key factor of the centrifugal molecular distillation technique. From a consideration of the mass and heat transfer mechanism, together with studies of fluid dynamics,surface evaporation phenomenon , a dimensional mathematical model for liquid on the tail-Waging round-arch shape evaporation turnplate. Simulation calculation program using VB6. 0 language computers the liquid film's flowing and evaporating characters respectively whether heat transfer occur or not, and drawing the distributing curves of film thickness δ film radial velocity u and film surface temperature Ts, summarizing the rules. 3 Combining with practical application, flowing characters ofdistillation fluid on round arch evaporation turnplate are experimented. Film radical velocity of flowage at the edge of turnplate un is measured. Through experimental data comparing with the results of Simulation calculation , the dependability of film's flow model are validated. The influence on flowing character un, and δA from Rotating speed of the turnplate ψ, quantity of the feed QL,evaporating turnplate'structure parameter e was observed . 4 Finally, the principal design schemes of centrifugal molecular distillation equipment are suggested. The novel viewpoint about the design of key components is brought forward.