Effects of walk-by and sash movement on contaminant leakage of air curtain-isolated fume hood.
The effects of the walk-by motion and sash movement on the containment leakage of an air curtain-isolated fume hood were evaluated and compared with the results of a corresponding conventional fume hood. The air curtain was generated by a narrow planar jet issued from the double-layered sash and a suction slot-flow arranged on the floor of the hood just behind the doorsill. The conventional fume hood used for comparison had the major dimensions identical to the air-curtain hood. SF tracer-gas concentrations were released and measured following the prEN 14175-3:2003 protocol to examine the contaminant leakage levels. Experimental results showed that operating the air-curtain hood at the suction velocity above about 6 m/s and jet velocity about 1 m/s could provide drastically high containment performance when compared with the corresponding conventional fume hood operated at the face velocity of 0.5 m/s. The total air flow required for the air-curtain hood operated at 6 m/s suction velocity and 1 m/s jet velocity was about 20% less than that exhausted by the conventional fume hood. If the suction velocity of the air-curtain hood was increased above 8 m/s, the containment leakage during dynamic motions could be reduced to ignorable level (about 10(3) ppm).
Huang
Rong Fung
RF
Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, ROC.
Chen
Hong Da
HD
Hung
Chien-Hsiung
CH
D000392:Air Movements; D004867:Equipment Design; D005740:Gases / Q000032:analysis; D015386:Hazardous Substances / Q000032:analysis; D019570:Inhalation Exposure / Q000032:analysis / Q000517:prevention & control; D007753:Laboratories; D016273:Occupational Exposure / Q000032:analysis / Q000517:prevention & control; D012906:Smoke / Q000032:analysis; D014691:Ventilation / Q000295:instrumentation*
D005740:Gases; D015386:Hazardous Substances; D012906:Smoke