auxiliary press-in fan

An auxiliary press-in fan is a localized ventilator used to deliver intake air to headings, faces, and bays through a duct network, ensuring the specified quantity at the point of work. Operating in positive-pressure mode, it helps dilute methane and diesel particulate, accelerates post-blast re-entry, and stabilizes thermal conditions to support safe and efficient mining.

Axial units are commonly selected for their compactness and high specific flow; in higher-resistance systems, contra-rotating axial stages provide additional static pressure without a large increase in diameter. Where explosive atmospheres may occur, explosion-proof electrical packages and anti-static ducting are mandatory. Pairing the fan with a variable-frequency drive (VFD) allows operators to adjust performance as duct length and system resistance change with advance.

Sound practice includes aerodynamic inlets, smooth transitions, sealed joints, and well-supported hangers to limit leakage and pressure penalties. A correctly proportioned face diffuser or nozzle spreads the jet and reduces recirculation. Selection should be based on a realistic calculation of total pressure, allowances for leakage and aging, and a fan curve that places operation near peak efficiency. Commissioning verifies face quantity and static pressure, while routine checks of vibration, temperature, and fasteners preserve reliability and acoustic performance.

• Function: local press-in ventilation for development work
• Benefits: assured airflow, gas and fume control, improved visibility
• Options: EX compliance, silencers, sensors, VFD control