NIOSHTIC-2 Publications Search
Fundamental Investigation of Exhaust Hoods.
Esmen NA; Weyel DA; Grauel TA; Ilori AG; Jossell S; Parris A
Department of Industrial Environmental Health Sciences, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania 1990 Aug:114 pages
This study investigated the theoretical aspects of airflow in front of freely suspended flanged hoods with arbitrarily, but symmetrically shaped hood orifices. Results indicated that an extension of the superimposition of two virtual sinks and potential flow assumption to describe the flow field can be used. The observed effect of turbulence on the capture efficiency of hoods and the magnitude of the reduction of the capture efficiency with what might be considered to be a relatively mild turbulent cross draft. Experimental data indicated that a turbulent cross draft in the order of 5 to 10% of the hood induced air speed in the mean velocity magnitude can reduced the overall capture efficiency of a hood by 15%. Using a conformal mapping technique, the theoretical investigations were also extended to include hoods with adjacent planes of arbitrary orientation. Optimization techniques which consider the hood geometry were investigated. The identified technique can be used to select hood orifice shape and dimensions not only to achieve proper control but also improve the mechanical efficiency of the process.
NIOSH-Grant; Control-technology; Exhaust-hoods; Air-flow; Ventilation-equipment; Ventilation-systems;
Industrial Environ Health Scis University of Pittsburgh 130 Desoto Street Pittsburgh, PA 15261
Final Grant Report;
NTIS Accession No.
Control Technology and Personal Protective Equipment; Research Tools and Approaches; Control-technology;
Department of Industrial Environmental Health Sciences, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania
University of Pittsburgh at Pittsburgh, Pittsburgh, Pennsylvania
Page last reviewed: September 11, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division