SOLID-PHASE CREEP DURING THE EXPRESSION OF PALM-OIL FILTER CAKES

For an adequate model of the processes of compressible cake filtration and mechanical expression, permeability and compressibility data are required Experimental and modeling results of the creep behavior of pa lm-oil filter cakes at constant and time-dependent pressures are prese nted. Creep curves of palm-oil filter cakes at constant pressures cann ot be modeled with linear viscoelastic models. Modeling with a modifie d form of the empirical equation of Nutting gives satisfactory results . This modification does not lead to unrealistic values of the porosit y at extreme conditions, contrary to the original form of the equation of Nutting. Creep curves at time-dependent pressures were modeled wit h two nonlinear viscoelastic models, which describe the time-dependent creep behavior as a function of the pressure history and creep curves at constant pressures. Modeling with the strain-hardening model provi des the best porosity predictions.