Pc. Bargale et al., Measurement of consolidation and permeability properties of extruded soy under mechanical pressing, J AGR ENG R, 74(2), 1999, pp. 155-165
A compression-permeability testing apparatus was developed to measure prope
rty functions of oilseeds relevant to mechanical pressing for oil recovery,
namely time-varying coefficients of permeability, consolidation and volume
change. The cell was designed to accommodate testing of different specimen
depths, under various compression pressures and temperatures. Properties w
ere measured for extruded soy for two specimen sizes (10, 20 g) compressed
at three pressures (20, 40, 60 MPa) and three temperatures (22, 60, 90 degr
ees C).
Consolidation and permeability property functions were significantly affect
ed by applied pressure, temperature, sample size and pressing time. Several
of the key assumptions of classical consolidation theory (as developed for
saturated soils) were violated for the extruded soy medium, namely, the as
sumption of incompressible solids phase and constant material parameters. I
n other words, the sample structure changed substantially during pressing.
The designed testing apparatus may be used to measure time-varying material
parameters for use with consolidation models that have been appropriately
modified for compressible oilseeds. (C) 1999 Silsoe Research Institute.