| 摘要 |
Apparatus for providing source capture of fumes produced at a work station including a molded aerodynamically designed fume capture hood positionable above the work station, a mounting mechanism for providing vertical movement of the hood such that the orientation of the hood opening remains constant, a fume collection system for removing material contained in air captured by the hood, and a flexible conduit connecting the collection system to the hood. The contours associated with the forward parts of the upper and side wall portions of the hood minimize entrance loss and turbulence to provide a coefficient of entry of at least about 0.93, while the contour associated with the forward part of the upper wall portion permits a higher velocity near the top of the hood for insuring suction of fumes, vapors or smoke near an operator's breathing zone. The mounting mechanism includes a vertical stanchion, a carriage slidably movable along the stanchion, pantograph-like mounting arms securing the hood to the carriage, and a constant force spring secured between the stanchion and the carriage, the spring acting to compensate for the weight of the hood and the conduit to maintain the hood at a desired vertical position.
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