Multilayer Screen Mesh Wicks for use in Temperature and Humidity Control

Condensate recovery from the temperature and humidity control system is an essential function for closed loop environmental control and life support system (ECLSS) design for continuous crew presence in space. This is made possible using a condensing heat exchanger (CHX) in which moisture condenses out of the air stream when cooled below the dew point of the cabin. A new method of collecting the droplets at the outlet of the CHX has been explored by Collins Aerospace, where a collection baffle using multilayer stainless steel, woven wire screen wicks are used. A mock-up was experimentally tested for feasibility and the results and observations are summarized in this paper. A CFD model of the airflow over varying baffle geometries was studied. The purpose of this development effort was to propose an improvement to the baseline THC system design which is used on the international space station (ISS), where the condensate collection portion of the system could be separated from the weldment of the CHX. An additional goal of this device was to potentially exclude hydrophilic coatings from the core design, as the flow regime in this proposed design relies on impinging droplets onto the baffle surface, rather than the state-of-the-art method in which the suction side of the rotary separator pulls in droplets adhering to the surface via surface tension. A comparison of the proposed system architecture to the on-orbit system is also reviewed in this work.