Abstract |
The report gives results of measurements of the control efficiency of various techniques used to mitigate emissions from open dust sources in the iron and steel industry. Of estimated emissions of 88,800 tons/year suspended particulate in 1978 (based on a 10-plant survey), 70, 13, and 12% were emitted by vehicular traffic on unpaved roads, vehicular traffic on paved roads, and storage pile wind erosion, respectively. |
Contents Notes |
Open dust sources in the iron and steel industry were estimated to emit 88,800 tons/year suspended particulate in 1978 based on a 10 plant survey. Of this,70, 13, and 12% were emitted by vehicular traffic on unpaved roads, vehicular traffic on paved roads, and storage pile wind erosion, respectively. Emission measurements, utilizing the exposure profile technique, indicate a 17% solution of a petroleum resin (CoherexR) in water on an unpaved road reduced heavy-duty vehicle emissions by 95.7% for total particulate, 94.5% for particulate <15[mu]m, and 94.1% for particulate <2.5[mu]m (averaged over the first 48 hours after application). Plain water reduced emissions 95% for all particle sizes half an hour after application. Four hours later, efficiency of watering had dropped to 55% (total), 49.6% (<15[mu]m), and 61.1% (<2.5[mu]m). CoherexR on an unpaved road travelled by light-duty vehicles reduced emissions by 99.5% (total), 98.6% (<15[mu]m), and 97.4% (<2.5[mu]m), 25 hours after application. Control efficiency decayed to 93.7% (total), 91.4% (<15[mu]m), and 93.7% (<2.5[mu]m), 51 hours after application. On paved roads, vacuum sweeping reduced emissions 69.8% (total), 50.9% (<15[mu]m), and 49.2% (<2.5[mu]m), 2.8 hours after vacuuming. Forty minutes after water flushing, emissions were reduced by 54.1% (total), 48.8% (<15[mu]m), and 68.1% (<2.5[mu]m). Combined flushing and broom sweeping reduced emissions by 69.3% (total), 78.0% (<15[mu]m), and 71.8% (<2.5[mu]m), 40 minutes after application. Control of emissions from coal storage piles varied from 90% to almost zero depending on the type of treatment, length of time since treatment was applied, and windspeed. Tests were performed using a portable wind tunnel. Relationships were developed to determine relative cost effectiveness of open source emission controls. |