Improving heat and mass transfer rates through continuous drop-wise condensation

Abstract

Drop-wise condensation (DWC) has been the focus of scientific research in vapor condensation technologies since the 20th century. Improvement of condensation rate in DWC is limited by the maximum droplet a condensation surface could sustain and the frequency of droplet shedding. Furthermore, The presence of non-condensable gases (NCG) reduces the condensation rate significantly. Here, we present continuous drop-wise condensation to overcome the need of hydrophobic surfaces while yet maintaining micron-sized droplets. By shifting focus from surface treatment to the force required to sweep off a droplet, we were able to utilize stagnation pressure of jet impingement to tune the shed droplet size. The results show that droplet size being shed can be tuned effectively by tuning the jet parameters. our experimental observations showed that the effect of NCG is greatly alleviated by utilizing this technique. An improvement by multiple folds in mass transfer compactness factor compared to state-of-the-art dehumidification technology was possible.

Preparation of porous membrane for moisture absorption from high‐humidity gases

“…The maximum moisture-holding capacity of the sample was determined by identifying the minimum time required to reach equilibrium. The initial moisture adsorption rate (v 0 ) was calculated using Equation (6), where v 0 (gÁg À1 Ámin À1 ) is the initial moisture adsorption rate, and M (gÁg À1 ) is the adsorption capacity after 5 min of moisture adsorption:…”

“…A relative humidity of 40%–60% is typically regarded as the best atmosphere for healthy and productive work 4,5 . Dehumidification techniques, such as condensation, 6 solution, 7 solid, 8 and membrane dehumidification, 9 play an important role in this regard. Condensation dehumidification is a process that utilizes the phase transition of substances to reduce the saturation of air containing water vapor by cooling it, resulting in the condensation of water vapor into liquid water 10 .…”