Generalized mathematical modelling of spray barriers

In this paper, experimental and theoretical investigations on liquid spray curtains are presented, in the context of absorbing and dispersing hazardous gaseous releases. The problem of release mitigation by absorption, either in pure water or in aqueous solution, was investigated or analytically solved by developing a general approach. The structure of the model includes a fluid-dynamic model describing air entrainment rate both in still air and in windy conditions, an absorption model, predicting spray efficiency and a mixing-dispersion model for the evaluation of the overall barrier effectiveness in environmental control. The model was validated by means of replicated experimental runs in a wind tunnel equipped with spray nozzles suitable to create a two-blade barrier. The model agreement with experimental data was fairly good in both cases of water and reacting curtain, which is promising for short-cut design purposes. The developed framework can be applied to more complex situations and different gas, allowing, as well, the attainment of a more generalized approach for the design of a curtain, once given the release parameters, the site layout and the sensitive target specifications.