A Profile of the Heat Generation Inside a Cigarette During Puffing

Abstract

The transient temperature distribution inside a burning cigarette during a 2-second constant-draw single puff was measured to determine the heat generation rate at various positions. The calculation of the heat generation was applied only to a vertically positioned cigarette. The solid-phase temperature was measured by an infrared thermometer with an optical fiber probe, and the gas-phase temperature was measured by a thermocouple. Heat generation rates at various positions inside the burning cigarette were obtained from the temperature distribution profile based on the heat balance equations. Heat generation was found to be concentrated within a region 2 to 3 mm behind the paper char line. The maximum heat generation rate was observed during the initial period of puffing and the heat generation rate decreased significantly in the interval during the middle unsteady period. Steady heat generation was observed in the latter period. The puffing volume as well as the properties of cigarette paper affected the heat generation rate during the unsteady period. The amount of the heat generated during the unsteady period was more than half of the total regardless of the cigarette paper basis weight and the puffing volume.

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

“…In a previous report (6) it was found that most of the heat generation inside the burning cigarette during puffing occurred in the region close to the paper char-line where the air is mainly flowing into the burning tobacco bed. Therefore, it is presumed that the weight loss of the cigarette during puffing is related to the oxygen transfer coefficient of the shredded tobacco bed, which affects the propagation rate in the reverse combustion of the tobacco bed.…”

“…To investigate details of the air inflow position into the burning cigarette and the flow rate outside the cigarette, we measured the transient change of the flow rate distribution outside the burning cigarette during puffing directly using the Particle Image Velocimetry system (5). We also estimated the net heat generation rate at various positions inside the burning cigarette during puffing by calculation from the heat balance equations using the experimental temperature profiles (6). Figure 1 shows the distribution of the flow rate outside the burning cigarette, the heat generation rate, and the solid-and gas-phase temperatures inside the burning cigarette during puffing.…”