Mechanics of cooling liquids by forced evaporation in bubbles

TL;DR

This paper investigates how forced evaporation in bubbles cool liquids, demonstrating that bubble growth depends on sub-cooling levels and developing a model that accurately predicts this process, offering an alternative cooling method.

Contribution

The study quantifies bubble growth dependence on sub-cooling and develops a phenomenological model validated by high-speed imaging, challenging previous assumptions.

Findings

Bubble growth depends on the degree of sub-cooling.

The developed model matches experimental observations.

Bubble cooling effectively cools liquids without complex techniques.

Abstract

Injecting a non-dissolvable gas into a saturated liquid results in sub-cooling of the liquid due to forced evaporation into the bubble. Previous studies assumed the rate of evaporation of liquid into the bubble to be independent of the degree of sub-cooling. In our study we quantify the bubble growth by direct observation using high speed imaging and prove that this hypothesis is not true. A phenomenological model of the bubble growth as a function of the degree of sub-cooling is developed and we find excellent agreement between the measurements and theory. This bubble cooling process is employed in cooling a liquid. By identification of all heat flows, we can well describe the cool down curve using bubble cooling. Bubble cooling provides an alternative cooling method for liquids without the use of complicated cooling techniques.