Research on fume hood. Effect on structure and dimensions of baffle plate on performance.

For getting high performance fume hood the authors obtained mainly the effect of structure and dimensions of baffle plate on suction velocity and static pressure by visualizing the air flow. The following conclusions can be drawn in this paper.(1) In the old fume hood model eddies growing inside box cause large static pressure, therefore loss is large.(2) By changing the upper suction port, the eddy vanishes and static pressure becomes extremely small.(3) Using "a" for upper suction port clearance and "b" for lower clearance, suction velocity is most uniform in the case of a/b??0.7. In the region of 30-50°of baffle plate angle it is scarecely affected.(4) Static pressure becomes smaller as clearance "a" and "b" increase, and becomes smaller as baffle plate angle increases.