Improved Traps for Removing Gases From Coolant Liquids

Two documents discuss improvements in traps for removing noncondensable gases (e.g., air) from heat-transfer liquids (e.g., water) in spacecraft cooling systems. Noncondensable gases must be removed because they can interfere with operation. A typical trap includes a cylindrical hydrophobic membrane inside a cylindrical hydrophilic membrane, all surrounded by an outer cylindrical impermeable shell. The input mixture of gas bubbles and liquid flows into the annular volume between the membranes. Bubbles pass into the central hollow of the hydrophobic membrane and are vented. The liquid flows outward through the hydrophilic membrane and is recirculated.