Porous Media Based Phase Separation in Condensing Heat Exchanger for Space Systems 2006-01-2275

One of the key elements of a recently proposed composite porous media condensing heat exchanger for space systems is to utilize capillary pressure for collecting and removing water from the condensing unit. This eliminates the need for rotary devices for phase separation under microgravity environments. The selective phase separation aspect of the design was investigated under controlled saturation of the porous substrate in terrestrial environment without the occurrence of condensation. Experiments were conducted with a composite porous system comprised of porous graphite block and porous ceramic tubes. It was demonstrated that the liquid phase could be preferentially separated from the unsaturated porous graphite block as proposed. This paper discusses the results of the selective phase extraction investigation. A flow model was also presented for predicting the phase separation by the composite porous system.