Application Of Inferential Control To Molecular Distillation Equipment

Molecular distillation technology as a pure physical separation method, the effective eparation of the heat-sensitive, high boiling point substances. Thus in the petrochemical, food and drug processing, daily cosmetics production has been widely used around the world. Molecular distillation technology to overcome the shortcomings of the currentdistillation method in a high vacuum state and better, and faster to achieve the separation and purification of the mixture of substances, which greatly improves production efficiency in the actual industrial production has a significant researchsignificance.Inferential control system can use the model to calculate the unmeasurable controlled output variables, the design inference controller, it is estimated that by measurable information in order to achieve the feedback control. Inference Control also previously feed-forward control for the purpose, projected the unpredictable disturbances in order to achieve the optimization of the control system performance.Today, domestic and international application of inferential control algorithm compared to the control field of control theory methods, in theory and in fact slightly immature, but its value in the control system can not be ignored. Inferential control of the accuracy of the mathematical model of demanding, in the practical engineering background, for example, in a continuous rolling mill production control strip thickness; and if pure oxygen top-blown converter in industrial production, carbon the control of the content. Both in the metallurgical industry or the petrochemical industry, sampling, measurement and other problems often encountered difficult for the controlled output. Inference control algorithm can solve these problems encountered in the actual industrial production.The experimental equipment used in this article is DCH-300model control equipment, a detailed theoretical study and serious operating under the premise of the process and characteristics of the three film molecular distillation equipment is analyzed. A clear exposition of the film flow process of molecular distillation equipment, and simplify the material on the heated wall evaporation link on this basis, the single-parameter model is reasonably applied to a molecular distillation process, the use of the Lord-sidestream dual circulation model simulation and Create a linear model to complete on the of Schisandra ester A matter of Schisandrin B matter of the simulation. Literature values and the calculated results compared and analyzed, each level wiped film evaporator, the evaporation temperature and feed rate parameters on the effect of separation, and further elaborated that the evaporation temperature and feed rate affect the separation and yield of the most important factor. The experimental data obtained in experiments with literature values coincide, thus confirming the correctness and feasibility of the established mathematical model.Through in-depth study of molecular distillation device parameters and process standards, combined with the unpredictable disturbances in Schisandra oil distillation, and the inference control algorithm, given the reasonable solution of the design reasoning controller and estimator. Inference control algorithm used in the molecular distillation Schisandra oil test, the complete control system design and optimization.Build the inferential control scheme for the device parameters and experimental requirements, design the inferential control system, solve disturbance unpredictable difficulties Schisandra oil distillation purification process, so as to achieve the purpose of improving purity and product yield, energy conservation.Application of S7-300series PLC to complete the design of the DCS control programs, vacuum control subsystem of the pilot project, scraping the film speed control subsystem, the evaporation temperature control subsystem, condensation control subsystem and material handling subsystem, to achieve the vacuum degrees, scraping membranes speed, evaporation temperature, condensation temperature, the material level, and transmission of flow control. Molecular distillation separation efficiency and energy savings to achieve the technical specifications of the project requirements.