摘要 |
<p>A containment, such as a glovebox (4), has an air extract system comprising suction means which extracts air from the containment through a vortex amplifier (1) mounted in a containment wall opening (2). The amplifier (1) serves to control the extent of suction extracted from the containment. Air exiting from the amplifier is drawn through a filter (32) removably arranged within a filter tube (31), which extends substantially parallel to the containment wall (3). A transfer passage (29), having a cross-sectional area less than that of the wall opening (2), provides a communication between an outlet side of the amplifier (1) and the filter tube (31). At least an initial portion of the transfer passage (29) extends perpendicularly to the wall. The filter tube (31) has open ends normally closed by covers (40, 41). Removal of the covers (40, 41) enables a clean filter to be installed in the filter tube while ejecting the used filter.</p> |