Hydraulic tests of a new centrifugal pump with shrouded impeller for extracorporeal membrane oxygenation systems

Abstract

AIMS: to determine and compare the head-flow characteristics of the new ECMO pump with the closed impeller when operating on water and water-glycerin mixtures. MATERIALS AND METHODS: a series of hydraulic tests of pump prototypes, manufactured using different technologies, was carried out. Three liquids were considered as the working fluid during the tests: process water at a temperature of 20 ⁰C, and two water-glycerin mixtures at a temperature of 20 ⁰C with different ratios of water and glycerin (to obtain different viscosities). RESULTS: the pressure characteristics of pump prototypes, manufactured using different technologies, were obtained using water and water-glycerin mixtures. For tests on water, it is shown that the deviation of the calculated and experimental characteristics does not exceed 4%, the deviation of the characteristics of prototypes, manufactured using different technologies, on average is 1.5%. Tests on a water-glycerin mixtures showed a deviation of the characteristics from those obtained on water on average is 6%, the largest deviation being observed at the edges of the characteristics. In addition, when tested on a water-glycerin mixture, the deviation of the characteristics of prototypes, manufactures using different technologies, is about 4%, which is higher than when tested on water. CONCLUSIONS: The results obtained allow us to conclude that the numerical model used in previous work can reliably predict the performance of the pump on water. The pressure characteristics of water and a water-glycerin mixture differ from each other, which must be taken into account when assessing the operating parameters of such pumps. The influence of manufacturing technology on the performance characteristics of the pump is higher when it operates on a liquid more viscous than water, eg on a water-glycerin mixture.