- Dettagli della rivista
- Pubblicato per la prima volta
- 01 Jan 1992
- Periodo di pubblicazione
- 4 volte all'anno
- Accesso libero
Comparative Investigations of the Influence of Polyvalent Alcohols and Fruit Extracts on the Physicochemical Properties of Tobacco
Pagine: 1 - 9
Laboratory investigations have been carried out into the application of water pectin extracts from dry apple pressings and orange peels as a moisture-retentive substance for use with tobacco from the unaromatizedRodopi blend. It has been established from comparative experiments with extracts, water pectin solutions and commonly applied humectants such as glycerol, diethylene glycol and propylene glycol that fruit pectin extracts can be used as humectants in tobacco production. The increase in the pectin content of the extract improves the moisture-retentive ability of tobacco, as does the addition of enzyme hydrolysate to the extract. The type of extracting acid has a definite effect. Tobacco treated with a nitric acid extract has better moisture absorption properties. The extracts decrease the tar and carbon monoxide deliveries in tobacco smoke compared to the usual humectants, glycerol, diethylene glycol and propylene glycol. The application of pectin extracts has a greater effect than the application of pure pectin solutions on the moisture-retentive properties of tobacco and the composition of tobacco smoke.
- Accesso libero
Pagine: 11 - 46
The objective of the theoretical study is to present a model that simulates the instationary flow characteristics within cigarettes which are adjusted to a routine smoking machine. By assuming laminar fluid flow the well knownKozeny-Carman equation is used to evaluate the flow impedance of cigarettes. The model parameters are determined by five variations of routine pressure-drop measurements yielding the entire set of flow impedances, which are necessary for describing a steady state Fluid-Network. Using this relation further elements of the fluid dynamics, e.g. the Fluid-Inductor, a storage element of kinetic energy (fluid inertor), and the Fluid-Capacitor, a storage element of potential energy (fluid volume), are evaluated. In addition, the electrical and fluid dynamical analogies are demonstrated. The model uses a set of distributed parameters including pneumatic impedances, capacitors and inductors, to represent filtered cigarettes and a second order linear partial differential equation to describe the fluid flow within the cigarettes. A simple presentation of the Fluid-Network with lumped parameters is analysed and its significant time constants are determined. A characteristical value for the time constant of the cigarette fluid-inertor is given by TL ≈ 0.02 ms and depending on the fluid volume of cigarette their dominant time parameter is given by TC ≈ 2 ms. Finally the transient fluid flow within cigarettes in a conventional smoking machine is considered including a simulation of their fluid dynamics. A simple estimation gives the time response of the system (consisting of cigarettes and routine smoking machine) with TcR ≈ 70 ms as a product of dead and sweep volume times the pressure drop of unencapsulated cigarettes. Variation of parameters caused by cigarette pressure drops and dead volumes of the smoking machine are simulated and discussed.