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 within the shell between loading, impregnating, and unloading positions. In the impregnating position, sealing assemblies seal the radial clearance between shell and the end members of the spool to provide a pressure vessel for tobacco impregnation. The sealing assemblies includes at least one elastically deformable sealing ring associated with the circumferential exterior of the end member. A pressure applying member is operatively associated with an axial end of each of the sealing members to releasably impart axial pressure onto the axial end of the sealing member when the spool is in the treating position to cause radial expansion of the deformable sealing ring and thereby accomplish sealing of the spool within the shell.

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.