Test of Development Condensing Heat Exchanger to Characterize Particulates and Metals Concentration in ISS Condensate 2001-01-2312

An evaluation of a development Condensing Heat Exchanger (CHX) was conducted at the MSFC ECLS Test Facility. The purpose of this test was to assess the effect of particulates and metals in the CHX condensate on downstream components, primarily the Air/Water Separator and the Back Pressure Relief Valve (BPRV). This test was performed using a flight-like CHX to simulate the particulate load and the concentration of metals from the ISS CHX coating. Two designs of the flight BPRV used on ISS were tested to assess the effect of particulates on the valve operation. As expected, the original design of the BPRV showed it was susceptible to particulate blockage. Particulate levels were not as significant as those observed in condensate generated during ground tests of the Lab and Airlock modules. The concentration of silver measured in the condensate varied throughout the test, thus additional testing will be required to define the steady-state concentration at nominal flow rates and estimate the life of the CHX coating.