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An overview of push-pull ventilation characteristics.
Appl Occup Environ Hyg 1990 Mar; 5(3):156-161
The characteristics of the push/pull ventilation control technique were discussed. The process was described as consisting of an air jet directed across an emission location and conducted through an exhaust hood. The free plane jet and the half jet were identified as the most frequently used in industry. Several nozzle configurations were discussed, including those with thin slots, closely spaced jets designed to merge into a single jet, and holes or slots in lengths of pipe. The maintenance of an even jet flow was stressed. Flow, velocity, and push/pull characteristics were estimated by Baturin's and Hemeon's equations, respectively. The importance of proper jet momentum and the determination of optimal momentum for a particular push/pull system were discussed. Jet distances of up to six times the slot length were considered satisfactory. Jet obstruction by small objects was not viewed as an important cause of spillage, although objects with large cross sectional areas could cause significant air flow deflection. The exhaust hood of push/pull systems was considered to require a flow rate of 1.5 to two times that of the jet, and this rate was of primary importance in hood design. Specific applications of push/pull systems were described, including plating tanks, air carbon arc gouging, foundry torch cutting, roller mills, multiopening presses, and wood panel gluing.
NIOSH-Author; Air-flow; Ventilation-systems; Work-environment; Air-quality-control; Exhaust-ventilation; Indoor-air-pollution; Industrial-ventilation; Safety-engineering; Ventilation-equipment; Indoor-environmental-quality
Issue of Publication
Applied Occupational and Environmental Hygiene
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division