Abstract: A low air volume exhaust hood is based on the concept of zone laminar flow through the hood as the hood sash is raised to different levels. Laminar flow is achieved through a plurality of plenum zones constructed at the rear of the cabinet. Preferably the zones are created by utilizing different sized openings in a rear baffle of the cabinet which presents the plenum chamber. Alternatively, distinct independent plenums may be formed and coupled with a common exhaust structure. By utilizing laminar flow which is directed through different zones corresponding to different open positions of the sash, a lower volume of air can be moved through the hood while achieving desired levels of evacuation. Performance of the hood is further enhanced by a novel air foil design at the floor of the hood which promotes a sweeping flow of air across the floor.

Abstract: 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.

Abstract: A method of evaporating liquid from a liquid and solid solution in a container within a chamber involves moving the container in an orbital motion such that the solution forms a vortex configuration within the container and also involves directing gas into the container. The gas is directed into the container from a point source above the liquid in the container to decrease the partial pressure on the solution thereby increasing the evaporation rate of the liquid from the solution. To further increase evaporation of the liquid, heat may be applied to the container. The temperature within the chamber may be regulated by sensing the temperature within the chamber and controlling the application of heat to the container in response to the temperature sensed within the chamber.

Abstract: A vortex evaporator having a holder for holding at least one container presents a chamber wherein liquid is evaporated from a liquid and solid solution in a container. The vortex evaporator also includes a drive mechanism, coupled to the holder, for moving each container in an orbital motion within the chamber to cause the solution in the container to form a vortex configuration. The vortex evaporator further includes a gas supply system for directing gas into the container to increase the evaporation rate of the liquid and a control system for controlling operation of the vortex evaporator. In an alternative embodiment, a vacuum supply system may be utilized instead of the gas supply system. Further, the vortex evaporator will preferably include a heater, at least one liquid level sensor, a heat sensor and a motion dampening assembly all located within the chamber.