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Mechanics of Constant‐Rate Filter Pressing of Highly Flocculated Slurries
Author(s) -
Kellett Bruce J.,
Lin ChiangYao
Publication year - 1997
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1997.tb02842.x
Subject(s) - slurry , materials science , consolidation (business) , mechanics , filter cake , piston (optics) , composite material , nonlinear system , pressing , volumetric flow rate , engineering , physics , chemical engineering , accounting , optics , wavefront , quantum mechanics , business
The growth of a powder compact from a highly flocculated slurry has been simulated by a computer program that models non‐steady‐state Darcian flow. Computer simulations have been compared with filter‐pressing experiments. Constant‐rate filter‐pressing experiments are divided into two regimes of piston stress—displacement behavior: an initial, almost‐linear, but concave‐up, regime during cake growth, followed by a second region of rapidly increasing piston stress when the piston comes into contact with the cake. Linear piston stress—displacement behavior is expected, from theory based on a uniform cake model. Highly flocculated slurries show highly nonlinear behavior. Nonlinear behavior is shown to be consistent with nonuniform growth of the cake. The permeability and consolidation behavior of the cake has been determined by a consolidometer experiment. Computer simulations indicate that the particle‐packing density profiles during cake build‐up are surprisingly similar during cake growth. Conditions for uniform consolidation can be determined from a general equation for non‐steady‐state Darcian flow. Results are directly applicable to constant‐flow‐rate pressure casting or slip casting.