Vapor-liquid contact, occurrence

Removal of sulfur dioxide from a gas stream. If a fuel that contains sulfur is burned, the product gas contains sulfur dioxide. If the gas is released directly into the atmosphere, the SO2 combines with atmospheric oxygen to form sulfur trioxide. The SO3 in turn combines with water vapor in the atmosphere to form sulfuric acid (H7SO4), which eventually precipitates as acid rain. To prevent this occurrence, the combustion product gas is contacted with a liquid solution in an absorption or scrubbing process. The SO2 dissolves in the solvent and the clean gas that remains is released to the atmosphere. 

A violent vapor explosion can result when a cold volatile liquid is suddenly brought into contact with a hot liquid. The explosion is due to the rapid vaporization of the cold liquid from heat transfer from the hot liquid. Such explosions are referred to as vapor, steam, physical, or thermal explosions rapid-phase-transitions (RPTs) (typically when referring to explosions involving cryogenic liquids) and molten fuel-coolant interactions (FCIs) when applied to nuclear reactor accidents. Accidental vapor explosions are frequent occurrences in the metallurgical, pulp and paper, and cryogenic industries. General reviews of the various aspects of vapor explosions can be found in Reid [1] and Corradini et al. [2]. 

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