Research On Pressing Theory And Experiment For Oil Plant

Edible oil is one of basic materials maintaining human life. Mechanical pressing is one of the most popular methods of oil separation from oil plant. The research on the mechanical behavior of oil plant in pressing has important theoretical significance and extreme engineering application value. On the bases of available achievements of pressing theory and experiment research, new researches have been carried out, which were as follows:(1) A visual testing apparatus has been developed to observe the microphenomenon and process of compression of oil plant. The conceptions of . oil-point pressure and strain were proposed. Experiments of oil-point pressure and oil expressed were carried out. The experiments for lateral pressure of oil plant were carried out.(2) The experiments of stress-strain of oil plant were carried out. The Effects of rate of applied pressure on the stress-strain was studied. The simulating model of stress-strain based on the Kawakita's Equation was developed. The prediction model of stress-strain of oil plant by using of BP neural networks was developed.(3) The microstructure of cakes of rapeseed decorticated, formed under uniaxial compression, was measured by using Quanta400 scanning electronic microscope and TIM-200 image analyzer. Using multiple regression analysis the porosity equation was developed based on experiments.(4) The conception of physical models of granular materials, semisolid saturationmaterial and cakes was advanced. The model can be identified by pressing rate. For the sake of improving precision of mathematical simulation of uniaxial compression, Hopfield neural networks was used to identify the coefficient of consolidation.(5) One-dimensional partial differential equation for fluids in porous media of oil cake was developed on the basis of theory of fluid-solid interaction, in which the cake is deformable and the permeability is variable. Analytic solution to problem of fluid-solid interaction of one-dimensional stead flow in porous media was proposed. The parameter inverse problems of permeability model of rapeseed cake and rapeseed dehulled cake, by using improved simulated annealing, was researched.(6) By using of Doraivelu's yield criterion, plasticity constitutive equations of rapeseed and rapeseed dehulled were developed on the bases of experiments.(7) By using of combining theoretical model with empirical model, the nonlinear visco-elastic-plasticity constitutive model of rapeseed and rapeseed dehulled was developed on the basis of the rheological test. The parameter inverse problems of constitutive model, using improved simulated annealing, was carried out.(8) In view of interaction of fluid flow field and rheology field, the interaction numerical method to the fluid flow field and rheology field was proposed, which adopted finite difference and finite element method. The deformations of rapeseed and rapeseed dehulled in pressing were simulated. The distribution and disappearance of fluid in rapeseed dehulled, and the distribution and change of effective stress of rapeseed dehulled were numerically simulated and predicted.