Fume hood with secondary exhaust collection device

摘要

A laboratory fume hood has a cabinet structure, which defines an enclosed work area, and a primary exhaust assembly. The primary exhaust assembly serves to contain fumes within the work area and then exhaust the fumes. It effects a flow of a volume of air through the work area and in many instances is designed to maintain a constant face velocity across an access opening in the front wall of the fume hood. A secondary collection device is disposed within the fume hood for removing a concentration of fumes from a small portion of the work area. The secondary collection device includes a collector head disposed in the work area and a conduit connected to the primary exhaust assembly. A portion of the air flowing through the work area is directed to the primary exhaust assembly through the secondary collection device. The volume of air passing through the secondary device should not be high enough to adversely affect the containment capabilities of the primary exhaust assembly. A blower may be provided to facilitate air flow through the secondary collector. A scrubber assembly or carbon filter assembly may be coupled with the primary exhaust assembly to purify the air collected by the secondary collection device.