Abstract: Mobilization apparatus for the treatment, drying for example, of particulate material comprises a mobilization zone bounded by upwardly divergent walls. Particulate material in the zone is mobilized by being subjected to a flow of gaseous mobilizing medium supplied at a multiplicity of sites of the divergent walls. The material is simultaneously subjected to a flow of gaseous accelerating medium supplied in an upward direction from a lower region of the mobilization zone. The obtains in the mobilization zone of circulatory pattern comprising downward flow at the divergent walls and upward flow from a lower region of the zone.In order to discharge the particulate material from the apparatus, a mask extending outwardly from the lower end of an upwardly extending discharge duct is brought to the upper end of the mobilization zone. The result is that the circulatory pattern is destroyed and the material is pneumatically transported up the discharge duct.

Abstract: Tobacco expansion apparatus comprises a transport duct in which can be established a flow of hot gaseous medium and into an upstream end of which can be fed particulate tobacco. The downstream end of the duct opens into the casing of a tobacco/gaseous medium separator comprising a separation screen.

Abstract: The method for expanding tabacco lamina comprises contacting the tobacco with an organic expansion agent, heating the thus contacted tobacco in a closed first vessel so that the temperature of the agent is above the boiling point of the agent at a lower release pressure, and suddenly venting the first vessel into a second vessel which is at said release pressure prior to the venting. By this means the fill volume of the tobacco is increased by a least 50%.

Abstract: In the expansion of tobacco, the tobacco is entrained in hot gaseous medium, separated from the gaseous medium and re-introduced and re-entrained in the gaseous medium before being once again separated from the medium.

Abstract: A tobacco expansion agent capable of synergistic tobacco expansion comprises a first organic compound which is volatile, non-polar and substantially water insoluble and a second organic compound which is volatile, water soluble, oxygen containing and of a polarity in excess of that of the first compound.

Abstract: A method and apparatus for reordering hot, dry expanded tobacco comprises a first reordering step in which the tobacco moisture content is raised to a first value, an intermediate cooling stage in which the tobacco is cooled to about ambient temperature (20.degree.-25.degree. C.) followed by a final reordering step in which the tobacco moisture content is raised to a final desired value.

Abstract: A smoking material comprises a binder consisting wholly or in part of a thermo-gelling substituted cellulose having a degree of substitution of at least 1.5 methoxyl groups per anhydroglucose unit, and an inert water-insoluble inorganic diluent such as chalk, which material has a density reduced by the entrainment and dispersion of air therein. The binder may comprise a thermo-gelling methyl cellulose having a degree of substitution of at least 1.5 methoxyl groups per anhydroglucose unit and/or an additionally substituted methyl cellulose having a degree of substitution of at least 1.5 methoxyl groups per anhydroglucose unit. It may additionally include a thermo-gelling cellulose having a lower degree of substitution or a non-thermo-gelling substituted cellulose.