摘要 |
<p>Process and apparatus for the treatment of tobacco material and other biological materials includes a mechanism comprising a dynamic seal having components (120,122) having cooperating movable surfaces for sealing a treatment chamber (50) that substantially prevents the passage of fluid at the treatment chamber pressure during movement of the components for introducing material into and removing material from the chamber. The seal components preferably comprise advanced structural ceramic components having a hardness of at least 900 kg/mm<2> and a flatness of at least 70 microinches (1.8 micrometres). The process is preferably conducted at supercritical gaseous conditions.</p> |