EXPRESSION OF UNSATURATED MIXTURES UNDER CONSTANT PRESSURE

Abstract

Expression mechanisms of unsaturated systems are analyzed where simultaneous flow occurs of pore gas and pore liquid through consolidated cakes, and basic equations for calculating expression operations are presented in this paper.
Expression processes are divided into two parts: instantaneous initial compression and so-called consolidation. Equations for the initial compression are analytically solved in view of the adiabatic compression of pore gas. Basic equations for the consolidation period are solved in the use of newly defined consolidation coefficient Ce. The operational variables for expression, i.e. void ratio e₁ due to initial compression, consolidation ratio Uc and final degree of saturation S₂, are well predicted from calculations based upon compression-permeability cell data. It is demonstrated that the amount of initial compression and the time rate of consolidation depend heavily on the initial degree of saturation.
Favourable coincidence between theory and experiments is confirmed for unsaturated mixtures over about 0.7 of initial saturation.