Ventilation Assessments of e-Waste Recycling Facilities during Normal and Abnormal Operating Conditions

Abstract

Waste facilities deal with dust, odours, and harmful gases. Designing an effective ventilation system for e-waste recycling facilities presents unique challenges due to the complexity of waste materials and potential emissions of hazardous air pollutants. This paper explores key considerations in designing an effective ventilation solution for e-waste facilities featured in an industrial showcase project in NSW, Australia. The facility comprises a Batch Rotary Pyrolysis (BRP) plant area to process waste electrical and electronic equipment, generating a flammable syngas during thermal treatment. Under abnormal conditions, this syngas may be released into the building, posing a fire hazard if ignited by unprotected electrical equipment near BRP machines or attached gas burners. To mitigate this risk, ventilation serves as the first line of defence against the accumulation of explosive gas concentrations, in alignment with AS1482-2013 standards. This study employs Computational Fluid Dynamics (CFD) analysis integrated with the site-specific wind rose to evaluate ventilation effectiveness, creating a detailed 3D model of the proposed facility, its surrounding structures, and natural ventilation components. A localised 10m-height reference wind rose was developed using The Air Pollution Model (TAPM) and CALMET diagnostic meteorological modelling software to provide accurate wind conditions for the project site. The CFD analysis delivers detailed insights, including airspeed distributions and predicted air exchange rates, highlighting hotspot areas with inadequate ventilation. Furthermore, the model facilitates comparative evaluations against regulatory standards by simulating concentrations of key gases (CO, SO₂, and NO₂ ) under abnormal gas leak conditions, ensuring that both safety and compliance are thoroughly upheld. The study offers comprehensive design input to refine natural ventilation systems, optimise opening sizes, and integrate mechanical ventilation where natural airflow is insufficient due to site orientation. This research demonstrates that an effective ventilation strategy for e-waste facilities can be developed when CFD modelling is incorporated early in the concept design stage. The proposed tool also has multiple downstream applications, including air quality and odour examination, thermal comfort assessment, fire risk evaluation, and smoke dispersion analysis.