A COMPARATIVE ANALYSIS OF THE MASS TRANSFER COEFFICIENTS OF THREE MODELS OF MEMBRANE BLOOD OXIGENATORS USING WATER AND A PERFLUOROCARBON EMULSION

Abstract

A dynamic method with water and a perfluorocarbon emulsion was used to determine the total mass transfer coefficients of three models of membrane blood oxygenators. The experiments were performed with blood oxygenators with exchange areas of 0.25, 0.7, and 1.6 m2. Experimental conditions were varied by changing gas flow rates from 0.5 to 6 l/min. and the liquid from 0.5 to 2.5 l/min. The Liquid phases used were distilled water and an emulsion formulated with Oxypherol FC-43 diluted with distilled water up to 18,5 % v/v. The experiments were done in triplicate totalizing 650 runs. The simultaneous scanning of two variables resulted in data in response surface form, which were plotted as three-dimensional graphic maps for the volumetric mass transfer coefficient Kla(s−1), the total mass transfer coefficient K(ml(O2 STP).cm−2.s−1.mmHg−1), and the t-Student normalized errors. Empirical mass transfer correlations were adjusted for these mass transfer devices by the variations in the gas and liquid flow rates. The mass transfer coefficient maps are useful to seek for the optimum operating conditions, to provide knowledge about the responses to variations on the operational situation, to help to evaluate new devices under development, to enhance the production quality control, to choose an equipment for a given situation, and as a marketing appeal, since it provides an impressive amount of information about the equipment's performance to the perfusionists.