Freeze-drying modified system

Instrumentation. Vacuum distillation of parfait column effluents was performed on an FTS Systems model FD-20-84, high-capacity, corrosion-resistant, freeze-drying apparatus modified as described in the text. 

This paper presents the application of a model based predictive control strategy for the primary stage of the freeze drying process, which has not been tackled until now. A model predictive control framework is provided to minimize the sublimation time. The problem is directly addressed for the non linear distributed parameters system that describes the dynamic of the process. The mathematical model takes in account the main phenomena, including the heat and mass transfer in both the dried and frozen layers, and the moving sublimation front. The obtained results show the efficiency of the control software developed (MPC CB) under Matlab. The MPC( CB based on a modified levenberg-marquardt algorithm allows to control a continuous process in the open or closed loop and to find the optimal constrained control. 

Uses Humectant, moisturizer for personal care prods., sunscreens, soap bars, dry skin creams, shampoos, liq. soaps emollient in aq. and hydroalcoholic prods. foam modifier in detergent and shampoo systems humectant, solvent, and solubilizer for topical pharmaceuticals freezing pt. depressant Properties Pale yel. thin syrup pract. odorless sol. in water, alcohol, hydroalcoholic systems acid no. 1.0 max. iodine no. 1 max. sapon. no. 1.0 max. hyd. no. 205-225 100% cone. 

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