Abstract
A new centrifugal ultrafiltration theory under centripetal-flow was developed to predict the filtration flux and the local filtration characteristics in the protein solute filter cake. The centripetal-flow cell is constructed whereby the centrifugal force vector is perpendicular to the membrane surface but opposite to the filtration flux vector for transmembrane flow. Therefore, this process makes it possible to maintain a high filtration flux by minimizing the cake formation on the membrane surface during ultrafiltration. By using a new centrifugal ultrafiltration equation for the filtration flux data, the values of the solute mass in the centrifugal filter cake were determined experimentally and the centripetal-flow ultrafiltration effects were quantitatively evaluated. The experimental results of bovine serum albumin solution in the pH4 to 9 and soy protein solution in the pH6.7 coincided favourably with the calculated results based on the new centrifugal ultrafiltration theory under centripetal-flow and the data of dead-end ultrafiltration.
