Criterial modeling of centrifugal separation process of massecuite III crystallization

Continuous filter centrifuges (CFCs) are used in the food, chemical and other industries. This type of machines is designed for separation of suspensions with undissolved solid phase, dehydration of crystalline and granular products, classification of materials by size, clarification of low concentration suspensions. Centrifuges of this type are also used for the separation of suspensions with a solid phase, particle size 5-74 microns and a volume content of 5-30%. A characteristic constructive feature of such centrifuges is a drum in the form of a hole rotor. When analyzing the process of suspensions separation into the CFCs quantitatively, it is necessary to take into account the flow structure, the kinetics of sediment formation on the rotor wall, the condensation of the liquid system being treated, and the particle size variation of the slurry. The aim of the work: from the viewpoint of the theory of the similarity of physical processes, using the example of the centrifugal separation of the third product's massecuite, to analyze quantitatively the kinetics of sucrose crystals isolation from the sugar-containing solution and dehydrate this solution in the working volume of the continuous filter centrifuge. The mechanical and geometrical parameters of the centrifugal equipment of the CFCs type, as well as the physicomechanical and dispersion characteristics of the liquid system being treated, were considered as the basis for the initial positions of the process under study. This allowed quantitative analysis of the kinetics of isolation from the sugar-containing solution of medium-dispersed sucrose crystals on the basis of physical and mathematical modeling, as well as to calculate the process of dehydration of this solution in the working volume of a continuous filtering centrifuge. As the controlling parameter of the process, the coefficient of clarification - the synthetic (integrative) index of the severity of the separation of the liquid system was used. As a result of a numerical experiment on the analysis of the dependence of the clarification coefficient on the productivity of a centrifuge on equipment of the FVI-1001K-1 type, data similar to those observed in a real centrifuge were obtained.