Analysis of the forced ventilation in containership holds

An analysis of the fluid flow and mass transfer induced by ventilation systems in containership holds was carried out. The result of the work was used to support the U.S. position before a committee of the International Convention on Safety to Life at Sea. The analysis consists of a detailed calculation of the forced motion through an interconnected set of narrow, stably stratified, vertical air passages, which represent an idealized containership hold. The results of this calculation were then used to predict the vapour concentration of spilled volatile material assumed to lie at the bottom of the vertical air passages. The result is a set of formulae which determine the rate of extraction of volatile material as a function of hold geometry, ventilation parameters, and ambient stratification. A variety of computed results are presented. The results indicate the crucial importance of locating the extractor as close to the hold bottom as technically possible.