Advances in Filtration and Separation Technology
Cake filters, Filters and filtration -- Mathematical models, Pore water -- Analysis, Porosity -- Measurement, Water -- Purification -- Filtration
During the initial stages of a Buchner funnel or specific resistance test, gravity drainage occurs prior to application of the pressure differential. Some allow time for a small cake to form by gravity drainage. Filtrate data from the gravity drainage period can be used to determine constitutive properties of the cake under a hydrostatic pressure gradient. The constitutive properties that define the structure of the cake include the permeability and porosity as functions of the applied stress. Equations governing the drainage rate during a gravity filtration experiment assuming a constant and a non-constant average cake permeability and cake porosity were developed. Numerical solutions were shown predicting the gravity drainage rate given known constitutive relationships. Also, a procedure was shown illustrating how constitutive relationships could be determined using gravity drainage data.
Wells, S., and Gregory K. Savage. "Gravity Drainage Prior to Cake Filtration." Advances in Filtration and Separation Technology, vol. 12 (1998): 646-653.