Dilution refrigeration minimum temperature

As a consequence of a release atmospheric dispersion occurs. The dispersion is airborne if the material is lighter than air. However, if is heavier than air it is dispersed as a dense gas. Additionally issues such as minimum released mass or minimum mass flow rates and the release temperature are considered in deciding on one of the two kinds of dispersion. A combination of both kinds of dispersion is possible. For example, refrigerated ammonia is initially dispersed as a dense gas and after being warmed by heat transfer from the surrounding air and diluted as an airborne gas. It should be noted that the release of any dense gas becomes airborne after a certain distance due to dilution of the gas with air (vid. Sect. 10.5). 

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