Evaluation of Combustion of a Shredded Tobacco Bed Using a Reactor to Produce Reverse Smolder: Influence of Properties Related to Mass Transfer on Combustion of the Bed

The combustion mechanism of a shredded tobacco bed during puffing has been investigated. To evaluate changes in the burning rate of the shredded tobacco bed in the region close to the paper char-line, an experimental study was carried out on the reverse combustion of the shredded tobacco bed packed in a furnace. Measurements of the temperature in the shredded tobacco bed were conducted to calculate the combustion propagation rate. The combustion propagation rate decreased with an increase in the tobacco shred width, the tobacco packing density, and with a decrease in the air flow velocity. To investigate differences in the combustion propagation rate, the oxygen transfer coefficient of the shredded tobacco bed was evaluated using the effective diameter of the tobacco shred and the effective surface area of the shredded tobacco bed. The combustion propagation rate of the shredded tobacco bed increased with the oxygen transfer coefficient of the shredded tobacco bed. Furthermore, the weight loss of the cigarette during puffing was evaluated. The weight loss of the cigarette during puffing showed an increase with an increase in the oxygen transfer coefficient of the shredded tobacco bed.