Ventilation of Industrial Process Drains: Mechanisms and Effects on VOC Emissions

Abstract

Recent studies have indicated the potential for emissions of volatile organic compounds (VOCs) from industrial process drains. An understanding of gas exchange rates between industrial sewers and the ambient atmosphere is a key parameter needed for improved estimation of VOC emissions. A two-phase study was completed to improve existing knowledge associated with ventilation of industrial sewers. In the first phase, theoretical models based on fundamental fluid mechanics and heat transfer kinetics were developed to facilitate improved estimation of emissions. In the second phase, experimental studies were conducted to evaluate the theoretical models. For 109 experiments, measured and predicted ventilation rates differed by less than a factor of two and were generally within ±30% of one another. Wind eduction and buoyancy-driven ventilation caused by the discharge of hot effluent streams to industrial drains were determined to be the dominant ventilation mechanisms.