Hydrophobic composite membrane gas-liquid separator with dynamic self-adaptive flow resistance of coupled valve-disk spring structure

In order to address the hazards caused by gas-liquid mixing or to utilize gases and liquids, this study proposes a preparation method for a hydrophobic composite membrane and a gas-liquid separator coupled with a valve-disk spring structure. By leveraging the hydrophobicity of porous polytetrafluoroethylene, a “liquid-blocking and gas-permeable” hydrophobic composite membrane with rigid support was prepared through multi-layer structure hot-pressing. The gas-liquid separator coupled with the valve-disk spring structure can stabilize pressure fluctuations. The structure provides a pressure difference of more than 99% for driving the separation, achieving multi-working-condition self-adaptation, and a pressure-drop equation was constructed to explain its mechanism of action. The gas-liquid separator can stably achieve separation at 36 kPa, with the pressure-difference fluctuation less than 5 kPa. The two-phase flow mechanism in the gas-liquid separation process was revealed through ultra-short timescale visualization technology. The step-like migration of the three-phase interface is influenced by Taylor flow and Kelvin-Helmholtz instability. The orthogonal experimental method was adopted to explore the influence of geometric dimensions and flow parameters on the separation performance of the device. The mechanism of the separation chamber length as a controlling factor was explained, and the characteristic curve of the separation limit was obtained. This innovative hydrophobic composite membrane and separator achieve real-time synchronization of pressure-difference-driven hydrophobic gas-liquid separation and two-phase flow, and have great application potential in phase separation in fields such as energy utilization, chemical manufacturing, microfluidics, and microgravity environments.