Modelling of auxiliary ventilation systems

In subsurface excavations, auxiliary ventilation systems are an important and integrated component of the overall ventilation scheme. Without adequate auxiliary ventilation, it is impossible to provide sufficient air to working faces, regardless of the quantity or quality of air in the main airways. Extended development headings are typically ventilated using fan and duct systems, which either force or exhaust air through the duct. The optimum design of such systems can be complex, depending on factors such as duct resistance, leakage and diameter, fan selection and spacing, and shock losses. This paper describes the development and application of a comprehensive design process for auxiliary ventilation systems. Included is a summary of published theory and literature, a description of software development, information and results from detailed field measurements, and a description of the application of the software to the design of an actual extended auxiliary fan and duct system.