Abstract
Severe air pollution problems are caused by the asphalt saturation of roofing felts and by blowing stills which prepare asphalts for use in saturators by removing the light fractions. The pollutant is mainly a small particle size fume of light oil. Eight different methods of removing the fume were investigated. Of these, five were rejected for inadequate efficiency or impracticability. Three, low-voltage electrostatic precipitators, high voltage electrostatic precipitators, and catalytic combustion, were examined for first cost and operating cost. Low-voltage electrostatic precipitators preceded by water sprays were selected as the most economical method. Two relatively successful installations are described.