Experiments on gas transfer to a film of blood through a membrane

The result of an increase in mean saturation of blood predicted by two mathematical models was verified by means of a series of experiments using cattle blood flowing in a 1.1 mm thick film, with flow rates ranging between 0.6 and 2.5 cc/min. The use of the equation of O2 transfer without taking into account the coupled CO2 transfer leads to slightly conservative predictions, and experimental data fit the calculated values of saturation within an error of 5%. For very slow flow rates the deviations reach 10%.Facultad de Ingenierí

Gas absorption with second-order chemical reaction in a packed column : Effects of contact-time distribution

Absorption of carbon dioxide into aqueous solution of sodium hydroxide was studied in a packed column under conditions such that the accompanying reaction was of the second order. In this case the average or volumetric reaction factor for the packed column, i.e. the ratio of the volumetric coefficients for absorption with and without chemical reaction, is complicated by the non-uniform contact-time distribution. However, the assumption of Porter''s "long, slow flow paths" model for the contact-time distribution led to a successful correlation for the average reaction factor.Facultad de Ingenierí

A mathematical model for transfer of O<SUB>2</SUB> and CO<SUB>2</SUB> in a membrane artificial lung

An analysis of oxygen absorption and carbon dioxide desorption in a film of blood through a gas-permeable membrane is presented. The mathematical analysis treats blood as a homogeneous, non-Newtonian fluid, in which the system pO2, pCO2 hemoglobin, pH is always in equilibrium due to the reaction rate in the erythrocites. Influence of flow rate, hematocrit and gas composition on blood saturation are studied, and the possibility of calculating an optimal membrane length is found.Facultad de Ingenierí