Liquid Pressure Distribution within Cakes in the Constant Pressure Filtration

Abstract

F.M. Tiller1), using a consolidometer, got the functional relation of the cake porosity (ε) to the pressure on cake-solid (Ps), and, applying this functional relation to the case of filter cakes, obtained indirectly the liquid pressure distribution curves.We, however, measured directly the liquid pressure distribution during actual constant pressure filtration, to investigate how the distribution varied with the filtrate volume (V), the concentration of the slurry (s) and the filtration pressure (Po). We used chiefly the slurries for ignition plugs, and a kieselguhr slurry as well. The liquid pressure was measured with the air-sealed glass capillary manometers as shown in Fig. 1.As the result, we got Figs. 7 & 13, from which we obtained(1)andν_??_0.48, for the ignition plug slurries within the range of Po=5.05-0.965kg/cm2ν_??_0.83, for the kieselguhr slurry.The value ν might be taken as a measure of the so-called incompressibility of the cake, and it seemed that ν was nearly independent of any of V, s and Po within the range of our filtration pressure experiments.The thickness of the cake (L) increased linearly with the filtrate volume (V), which proved the m-value to be coincident with the m-value obtained by the method described in our former report2).