Effect of Machine Smoking Intensity and Filter Ventilation Level on Gas-Phase Temperature Distribution Inside a Burning Cigarette

Abstract

SUMMARYAccurate measurements of cigarette coal temperature are essential to understand the thermophysical and thermochemical processes in a burning cigarette. The last systematic studies of cigarette burning temperature measurements were conducted in the mid-1970s. Contemporary cigarettes have evolved in design features and multiple standard machine-smoking regimes have also become available, hence there is a need to re-examine cigarette combustion. In this work, we performed systematic measurements on gas-phase temperature of burning cigarettes using an improved fine thermocouple technique. The effects of machine-smoking parameters (puff volume and puff duration) and filter ventilation levels were studied with high spatial and time resolutions during single puffs. The experimental results were presented in a number of different ways to highlight the dynamic and complex thermal processes inside a burning coal. A mathematical distribution equation was used to fit the experimental temperature data. Extracting and plotting the distribution parameters against puffing time revealed complex temperature profiles under different coal volume as a function of puffing intensities or filter ventilation levels. By dividing the coal volume prior to puffing into three temperature ranges (lowtemperature from 200 to 400 °C, medium-temperature from 400 to 600 °C, and high-temperature volume above 600 °C) by following their development at different smoking regimes, useful mechanistic details were obtained. Finally, direct visualisation of the gas-phase temperature through detailed temperature and temperature gradient contour maps provided further insights into the complex thermophysics of the burning coal. [Beitr. Tabakforsch. Int. 26 (2014) 191-203]

Integration of Time and Spatially Resolved In-Situ Temperature and Pressure Measurements With Soft Ionisation Mass Spectrometry Inside Burning Superslim and King-Size Cigarettes

“…A series of temperature and gas-flow velocity maps were produced that characterized the dynamic combustion system in the cigarette in response to an externally applied air flow (12). Our approach builds on recent work by LI et al in which a semi-automatic sampling stage was used to obtain two-dimensional measurements of temperature and pressure inside a burning cigarette, yielding gradient maps of temperature and pressure as a function of time during smouldering and puffing (21)(22)(23)(24). The temperature and pressure sensor arrays were combined with a microprobe for simultaneous sampling of the gas flow for chemical analysis by single-photon soft ionisation time-of-flight mass spectrometry (SPI-TOF-MS) (12), an analytical technique that allows both real-time measurements of volatile organic compounds, and on-line puff-bypuff monitoring of tobacco smoke constituents ranges (26,1,2,27).…”

Effects of Varying Tobacco Rod Circumference on Cigarette Combustion: An Experimental Investigation

“…The cigarette combustion temperature measurement system used in this study has been described before (20)(21)(22). To provide a brief description: the system consisted of a thermocouple insertion kit, a single-port smoking machine and a high-speed analogue-to-digital converter.…”

“…In order to describe the cigarette burning process in detail, several temperature parameters were defined and used in our previous studies (20)(21)(22). During the cycle of smoldering and puffing, the coal volume (V) is experiencing constant fluctuations as a result of the forced air flow.…”

“…Recently, our group has developed a special test module composed of eight thermocouples for a more accurate characterisation of the combustion or pyrolysis conditions of the burning coal (20). Based on this technique, the temperature distribution of the combustion coal under different puffing conditions, levels of filter ventilation and other cigarette design parameters have been investigated (21,22). To our knowledge, there has been no systematic study in the literature on modern cigarettes which examined the effects of cigarette circumference on the combustion dynamics and on smoke yields.…”

Pressure and Gas Flow Distribution Inside the Filter of a Non-Filter Ventilated Lit Cigarette During Puffing

“…The thermocouple module used in this work for temperature measurements was the same as the one described before (24,25). Briefly, up to eight K-type thermocouples (0.254 mm outer diameter) were loaded into a digital x-y stage for positioning and insertion (accuracy within ± 0.1 mm).…”