Developments in push-pull ventilation.
NIOSH 1986 Oct; :47-50
Recent developments in push/pull ventilation were discussed. The nature of push/pull ventilation was described. Push/pull ventilation involved using jets or curtains of air in conjunction with local exhaust ventilation to direct the flow of ambient workplace air. The net effect was to enhance the effectiveness of normal local exhaust ventilation. Research studies in the area of push/pull ventilation conducted by NIOSH during the last 4 years were summarized. A laboratory study of the effect of push/pull ventilation on emissions from a mock plating tank utilizing a heated water alcohol bath was conducted. Push/pull ventilation achieved capture efficiencies of 90 to 95 percent and reduced the pull flow necessary to achieve this flow to less than 50 percent of that normally required for normal local exhaust ventilation. In field testing, an average air level of 0.032mg/m3 chromium(VI) (18540299) was achieved for a chrome plating ventilation system. Laboratory and field studies of foundry air carbon arc gouging and torch cutting operations showed that push/pull ventilation reduced exposures to metal fumes to less than 0.80mg/m3 for carbon arc gouging and to 1.65 to 6.11mg/m3 for torch cutting. Field studies of rubber and plastic milling operations showed that push/pull ventilation using an air curtain reduced mill emissions by over 50 percent with a concomitant 33 percent reduction in exhaust airflow. The air curtain also reduced heat stress created by the hot plastic. The authors conclude that push/pull ventilation can provide cost savings and permit emission control that could not be achieved by local exhaust ventilation alone.
NIOSH-Author; Occupational-health; Control-methods; Air-flow; Air-quality; Laboratory-testing; Ventilation-systems; Laboratory-techniques
The Changing Nature of Work and Workforce, Proceedings of the Third Joint US-Finnish Science Symposium, Frankfort, Kentucky, October 22-24, 1986, NIOSH, Cincinnati, Ohio