Specific Resistance Measurements: Nonparabolic Data

Abstract

A computer‐aided data acquisition system was developed for the generation of slurry filtration data. The system has some advantages over the traditional Buchner funnel apparatus, including: (1) Operation at pressure differences up to 200 psi (1.4 MPa); (2) a more desirable aspect ratio for the filtration vessel; (3) the ability to record filtrate volumes at intervals of 1 s or less; (4) improved accuracy and precision; (5) avoidance of the need for constant attention to data collection during filtration experiments; and (6) convenient computerized manipulation of data. The data acquisition system was used to investigate nonparabolic filtration behavior. The results show that nonparabolic filtration data are associated with filtration runs accompanied by sedimentation prior to filtration, sedimentation concomitant with filtration, or slurry‐media interactions. In many instances, nonparabolic filtrations can be redone to produce parabolic filtration data by applying pressure immediately following the introduction of the slurry into the filtration vessel, thickening the slurry prior to filtration to reduce the significance of sedimentation with respect to filtration, and choosing a different support medium.