Abstract: Processes and apparatus are provided for processing tobacco for expansion thereof including process and apparatus for forming a batch of tobacco for delivery to a tobacco impregnation apparatus and processes and apparatus for unloading the expanded tobacco and purging expansion agent from the expanded tobacco. The tobacco batch forming and feeding system forms and feeds tobacco batches of predetermined weight which can be readily changed to accommodate different types of tobacco. Expanded tobacco is unloaded directly into an unloading chamber wherein expansion agent is purged from the expanded tobacco. The tobacco unloading chamber includes a purge gas circulation system for circulating the purge gas through the expanded tobacco in the lower portion of the unloading chamber and removing the released expansion agent from an upper portion of the unloading chamber.

Abstract: A process and apparatus for tobacco expansion is employed for expanding tobacco at rapid throughput rates. The apparatus includes a spool and shell assembly wherein the spool is moveable into and out of the shell between loading, impregnating, and unloading positions. In the impregnating position, sealing assemblies seal the radial clearance between the spool and shell to provide a pressure vessel for tobacco impregnation. The sealing assemblies include at least one elastically deformable sealing ring and an annularly shaped axial pressure applying member to releasably impart axial pressure to the sealing ring. The axial pressure applying member receives fluid pressure from a hydraulic fluid and preferably receives additional fluid pressure from the expansion agent used to expand the tobacco.