CORESTA Meeting, Smoke/Technology, Hamburg, 1997, ST12
A study of the effect of cigarette rod construction on filtration efficiency
Philip Morris USA, Research Center, Richmond, VA, USA
Since the pressure drop and ventilation levels are the most important parameters contributing to filtration efficiency, it follows that one can predict changes in efficiency if changes in pressure drop and ventilation are predicted. An earlier paper demonstrated the ability to predict ventilation levels and pressure drop. The continued study of the volumetric flows generated in the dynamic interactive system, called a ventilated filtered cigarette, has resulted in additional predictive tools. The effects on filtration efficiency with changes in tobacco rod construction and its changing length during consumption are represented mathematically in this study. The consumption of the tobacco rod is more than a reduction in length, it also presents an additional pressure drop term and changes in the dynamic volumetric flows resulting from the burning coal. Presented is a mathematical model that predicts the total cigarette pressure drop and filter ventilation values. The model is flexible enough to predict the ventilation and pressure drop changes of any filter constructions. This capability gives the ability to predict filtration efficiency on a puff-by-puff basis.