Implementation and validation of an innovative method for fluid mechanical characterization of haemo-catharsis modules

Abstract

Proper fluid-mechanical characterization of haemo-catharsis (HC) modules is indispensable for optimizing their design and operation. A recently developed methodology allows determination of (heretofore ignored) significant pressure losses in the headers of HC-modules, taking into account the main fluid-mechanical phenomena through appropriate/representative parameters. The latter comprise friction coefficients ff and fs (for fiber-lumen and shell-side flow), membrane permeance K and four parameters ζi1-ζi4 representative of pressure drop in the module-headers. A mechanistic model and pressure/flow-rate measurements, taken with two specially-selected operating modes, are used for such parameter estimation. Implementation of this methodology is reported herein, to the practically important case of counter-current flow, that involves theoretical-model extension/adaptation and experiments with liquids of viscosity 1 cp and 2 cp. These data are employed to investigate and optimize the data-fitting procedure (considering computational accuracy/stability and convenience) and to validate the counter-current flow model. Assessment of experimental and theoretical-model results suggests that the procedure involving data from the two special operating-modes is essential for facile implementation of the novel methodology, including the accurate determination of membrane permeance K. The methodology developed, allows reliable prediction of the key spatially-evolving process-variables, and is recommended for practical applications and advanced overall HC-module performance modeling. Suggested future work is outlined.