摘要 |
Chromatography apparatus and methods are described, especially for expanded bed adsorption. A column tube (1) has a process fluid input device (41) at the bottom and a movable piston (2) in the top. The piston (2) is enclosed in the column by a top cover plate (3). The piston body (21) has a peripheral inflatable seal (23), and is connected by an open frame (85) to a contact ring (81) above which carries another inflatable annular member (83) to contact the tube wall. Process fluid leaves the operating volume (13) through a central opening of the piston and flexible hose (9), through the enclosed space and out through the cover plate (3). The space (77) above the piston (2) can be pressurised to control piston movement. The contact ring (81) maintains piston alignment. The inflatable seals (23,83) can be inflated or deflated to fix the piston in position, allow it to slide or allow washing. The piston outlet may include a vortex-inhibitor. Bed and piston levels may be monitored by ultrasound sensors. |