| Summary: | 碩士 === 國立交通大學 === 工學院產業安全與防災學程 === 104 === The inclined air-curtain (IAC) fume hood employed in the present work was constructed with the cross-flow fan at the bottom, deflection plate along the side walls, and a suction slot at the top of the cabinet. The containment in the cabinet were controlled effectively by using the two-dimension blow velocity and suction velocity.
A research of an IAC walk-in fume hood performance was operated in several methods. Face velocity was measured on sash opening plane to know the distribution and it’s average face velocity. Tracer-gas testing of the IAC walk-in hood was performed in two ways. One is in accordance with the methodology described in EN14175-3 Fume cupboards-Part 3：Type test methods. Tracer gas is 10%SF6 in nitrogen balance. Another one is self-developed method. Tracer gas is 5%SF6 in nitrogen balance and it is released by own designed ejector.
The mean leakage SF6 concentration is less than 0.005 ppm by inner test method based on EN14175-3. The peak concentrations are 0.027 ppm. It is classified as “Good” grade in Invent UK 2004 Standard. The tracer gas concentrations are less than 0.005 ppm in 10cm、15cm、20cm and 25cm sash opening by self-develop method. In 30cm and 35cm test, the peak concentration are 0.011 ppm and 0.01 ppm.
The average concentration of SF6 is 0.093ppm, peak concentration is 0.28ppm at Hej=60cm、H=20cm~100cm sash movement test. The average concentration is 0.041ppm, peak concentration is 0.108ppm at Hej=(74,40,60)cm、H=20cm robustness test. Both of results are met the limit values of professional association of the Germany chemical industry technical committee chemistry. When the blow jet velocity (Vb) decreased, the containment efficiency also reduced at sash movement test and robustness test. This result showed that an adequate blow jet velocity would provide a higher containment performance.
|
|---|
