Speakers Discuss Better Practices.

This year's six presentations by the Environmental Control Committee (Div. 10) covered the gamut of hot topics with panels that offered updates on pending silica and maximum achieveable control technology regulations to sessions that focused on environmental improvements on the shop floor.

In their presentation (103) on ergonomics issues, N.M. Oda, S.D. Choi, and T.K. Fredericks, Western Michigan Univ., discussed their study of the biomechanical stresses imposed on workers during manual metal-pouring operations. The authors performed a video analysis to identify current pouring methods and to determine the compression and shear forces on the lower back of the pourers. They identified three primary tasks: retrieving metal in a ladle from the furnaces, carrying the metal to the molds and pouring the metal into the molds. The Univ. of Michigan's 3-D Static Strength Prediction Program was used to estimate L5/S1 disc compression and shear forces.

The presenters found that the disc compression forces for retrieving metal and pouring it into the molds exceeded recommended limits. Based on these results (and a previous study that found that pouring operations exceed acceptable limits for energy expenditure), they concluded that manual pouring operations are "strenuous." To reduce the risk of injury, the authors recommended reduced load distance from the furnace to the mold and working temperature; training in proper lifting techniques; and redesign of ladles to accommodate the workers.

In their presentation (112), J.C. Liello and R.C. Scholtz, RMT, Inc., discussed a "holistic" approach to foundry air ventilation. This approach uses data from air mass balancers, real-time air contaminant profiles, area samples and tracer gas simulations of contaminant dispersion to form a composite picture of ventilation conditions.

Based on this balanced approach, foundries can reduce cross-contamination by subdividing ventilation into multiple zones (which reduces the distance between fresh air introduction and exhaust) and using local ventilation controls to capture emissions at the source. In addition, energy can be conserved by using tempered and untempered makeup air.