Centro de Documentacion de Fundación MAPFRE - Comparison of three tracer gases for determining ventilation effectiveness and capture efficiency

Notes: Sumario: Sulphur hexafluoride, nitrous oxide and helium were compared as tracer gases for determining the mean residence time in a test room and the capture efficiency of a local exhaust hood. The mixtures of tracer gases were fed into the inlet air and two sites in the test room with and without mixing of room air. It dertermined the capture efficiency by releasing the tracer gases through the cylindrical injection system in front of the exhaust hood at different capture velocities under various cross-draught conditions. The results of the measurements in the test room showed good agreement between the different tracer gases except in the stagnant zone. The first capture efficiency measurements indicated that SF6, the heaviest gas, gave smaller values obviously due to imcomplete mixing of tracer gases. However, the difference disappeared when mixing of the tracer gas was speeded up pumping extra air or by modifying the injection systemRelated records: En: The Annals of occupational hygiene. - Oxford [etc.]. - nº 4, August 1991 ; p. 405-417Materia / lugar / evento: Higiene industrial Contaminantes químicos Gases tóxicos Control de contaminantes Contaminación atmosférica Helio Oxido nitroso Hexafluoruro de azufre Sistemas de ventilación Ventilación Otros autores: Niemelä, R.
Secondary titles: Título: The Annals of occupational hygiene
Other categories: 872