| 摘要 |
<p>A laboratory bench-top fume hood comprises an enclosure (11, 21) containing a working chamber (2) with a frontal opening (3), for manual access to the chamber (2) and for air to flow into the chamber (2). A plenum chamber (4) at the rear of the working chamber (2) is connectable to an air extraction system. An apertured, curved baffle plate (16) separates the working chamber (2) from the plenum chamber (4). The baffle plate (16) is concave from the working chamber (2) side and convex from the plenum chamber (4) side, improving airflow and increasing the usable volume of the working chamber (2). The slots (7) in the baffle plate (16) may be fitted with guide vanes extending into the plenum chamber (4), better to direct airflow therethrough. A slot (17) adjacent a roof of the working chamber (2) is particularly effective for creating evenly-distributed air flows. The roof (22) may be curved to encourage an airflow to follow the roof profile to the baffle plate (16). Side walls (42) of the working chamber (2) may bow outwardly but converge towards the opening (3), to increase useful working volume while improving airflow paths. The baffle plate (16) may comprise a set of separately dismountable panels, to aid cleaning and to provide access to the plenum chamber (4).</p> |
