Experimental Methods for Investigating the Discrete Droplet Impact Phenomena of a Model Fluid Relevant for LNG Heat Exchangers Available to Purchase

To improve knowledge on the design and operational issues of heat exchangers used in the liquefaction process of liquefied natural gas (LNG), experiments were conducted to investigate the complex two-phase flow phenomena in an n-pentane environment. Special focus was placed on characterizing the impact thresholds (bouncing, coalescence, splashing, etc.) of n-pentane droplets impinging on a flowing liquid film of various angles. In the phase diagram of velocity and diameter, the threshold of splashing for n-pentane was found to be below that for water (i.e. lower translational energies lead to splashing). The splashing threshold was well-characterized by a model reported previously for water droplets on stationary surfaces, adjusted slightly for non-normal impacts, which is influenced greatly by the thickness of the liquid film. In addition, the bouncing threshold of n-pentane was found to decrease with higher liquid film velocities with a threshold generally lower than that of water.