Dead-End Flow Filtration of Solid Suspension in Polymer Fluid through an Active Kaolin Dynamic Membrane

ABSTRACT

In this study an active kaolin dynamic membrane formed on a SS-316 porous support was used to investigate the microfiltration of a solid suspension in polymer fluid. It was found that a homogeneous sodium acetate suspension in polymer can be completely removed by the active kaolin dynamic membrane to yield a very clear polymer product. The filtration rate as a function of operating temperature and pressure were experimentally determined. When the operating temperature was increased, the decreasing polymer viscosity resulted in an increase of filtration rate but was counteracted by the swelling effect of the membrane layer. Similarly, when the pressure was increased, the increase in driving force for filtration was counteracted by a simultaneous increase in particle packing. The filtration behavior of this dynamic membrane system was also simulated by the general blocking model d ² t/dV ² = k(dt/dV)^q, where q was found to have negative values. Negative q values mean that our system reached a maximum blocking rate during the initial period of filtration and then decreased gradually. When the blocking rate became small enough, the system behaved like cake filtration. A satisfactory fit between experimental data and theoretical calculations was demonstrated.

Key Words::

• Microfiltration
• Dynamic membrane
• Polymer fluid
• Active kaolin
• Theoretical analysis