Convective Heat Transfer Measurements in Cigarettes

An unsteady-state technique has been used to measure convective heat transfer coefficients in the tobacco rods of American and British cigarettes. The coefficients measured in dry cigarettes near room temperature at flow rates from 7.6 to 28 cm³/s increase linearly from 0.0003 to 0.0012 cal/(cm² s °C). Because of channeling of the gas flow in the relatively porous (70-80 %) tobacco rods, these heat transfer coefficients are an order of magnitude lower than those for large scale packed beds, in which the gas flow is more evenly distributed.