Abstract: A method of and an apparatus for expanding tobacco, particularly tobacco impregnated with solid carbon dioxide are disclosed. The apparatus comprises an arcuate, generally C-shaped duct for conveying the tobacco material in a hot gaseous medium to sublimate the solid carbon dioxide and expand the tobacco. The duct has a non-circular cross-section, preferably a rectangular cross-section, with a high width-to-depth ratio and an increasing depth from the inlet to an intermediate portion of the duct then a decreasing depth from the intermediate portion to the outlet of the duct. A winnower device infeeds the tobacco material into the duct adjacent the throat of a venturi section connected to the inlet of the conveying duct. A tangential separator with an adjustable baffle at the inlet thereof for controlling velocity in the separator is used to separate the expanded tobacco from the gaseous medium.

Abstract: An apparatus for impregnating tobacco with an expansion agent includes a chamber for confining a charge of tobacco under elevated pressure conditions. An accumulator connected to the chamber maintains a supply of an expansion agent in fluid form under conditions of elevated temperature and pressure but less than the desired tobacco impregnation temperature and pressure. The expansion agent is forcibly and rapidly moved from the accumulator and introduced into the chamber under conditions such that the pressure and temperature of the expansion agent are increased to the desired impregnation temperature and pressure, preferably including a pressure approaching or above the supercritical pressure thereof.

Abstract: A tobacco expansion process and apparatus is provided to form a tobacco batch having a predetermined amount of tobacco, contact the batch with steam, load the batch onto a spool assembly, and impregnate the batch with an expansion agent. A double conduit apparatus is provided to load two simultaneously formed tobacco batches onto opposing sides of the impregnation spool. The tobacco batch is formed within a batch forming chamber comprising a vertically adjustable screen to accommodate different operating parameters and/or different tobacco types and/or forms. The batch is directed through a pneumatically separable zone to a precompaction and heating zone. The separable zone is defined by sequentially operating members, at least two of which form barriers to impede seepage of the expansion agent from the impregnating zone. In the precompaction zone the batch is precompacted against a permeable barrier, steamed, and then loaded onto a spool assembly for impregnation with an expansion agent.

Abstract: A tobacco expansion apparatus is provided to form a tobacco batch having a predetermined amount of tobacco, contact the batch with steam, load the batch onto a spool assembly, and impregnate the batch with an expansion agent. A double conduit apparatus is provided to load two simultaneously formed tobacco batches onto opposing sides of the impregnation spool. The tobacco batch is formed within a batch forming chamber comprising a vertically adjustable screen to accommodate different operating parameters and/or different tobacco types and/or forms. The batch is directed through a pneumatically separable zone to a precompaction and heating zone. The separable zone is defined by sequentially operating members, at least two of which form barriers to impede seepage of the expansion agent from the impregnating zone. In the precompaction zone the batch is precompacted against a permeable barrier, steamed, and then loaded onto a spool assembly for impregnation with an expansion agent.