Study on combustibility and particle size distribution in smoke aerosols of cigarettes with different circumferences
In order to investigate the effects of cigarette circumference on its combustibility and particle size distribution in smoke aerosol, the solid phase temperature of combustion cone and the gas phase temperature in filter tip of the same brand cigarettes with three circumferences (ø 24.37 mm, normal; ø 20.06 mm, medium; ø 17.02 mm, slim) were tested by infrared thermal imager temperature measurement technology and thermocouple temperature measurement method, respectively. Meanwhile, a smoking cycle simulator and a fast particulate spectrometer DMS500 were employed to determine the particle size distribution in smoke aerosol under ISO smoking regime. The results showed that: (1) The solid phase temperature of the combustion cone of medium and slim cigarettes was higher than that of normal cigarettes by 100 °C on average. (2) The gas phase temperature at the front of the filter of medium and slim cigarettes was higher than that of normal cigarette by 5 °C; however, the gas phase temperature in filters of the three sizes of cigarettes tended to be consistent due to the cooling effect of filters. (3) With the decrease of cigarette circumference, the average particle number concentration of aerosols for all puffs increased significantly, while the count median diameter (CMD) decreased, which indicated that the number of fine particles increased. (4) With the decrease of cigarette circumference, the average particle surface area of aerosols for all puffs increased significantly, and the area median diameter (AMD) reduced, which suggested that the total area of fine particle increased remarkably.