Booster Fans -- Some Considerations for their Usage in Underground Coal Mines

A booster fan is an underground fan installed in series with a main surface fan and used to boost the air pressure of the ventilation air passing through it. Currently booster fans are used in several coal mining countries including the United Kingdom, Australia, South Africa and China. In the US they are used in several metal and non-metal mines however, due to concerns of uncontrolled recirculation, coal mine operators have not been allowed to use them. This paper presents some design considerations pertaining to installations where booster fans are in use in non-US underground coal mines and which are achieving safe and efficient atmospheric conditions. They are found in high and low gas conditions and on occasions where workings are located at great depths (greater than 1000 m below surface). Booster fan installations may be found in Mains ventilation headings where they influence flow throughout the mine, in Section headings where influence is principally on one working face or where they allow for recirculation of uncontaminated return air into the intake. Booster fans are designed with interlocking systems to control, for instance, underground fans and avoid recirculation when surface fans are unexpectedly turned off. Mine atmospheric monitoring systems are in common use. A study is described that has objectives to investigate considerations relevant to operation of booster fans safely and efficiently in underground coal mines within the context of US mining. The study is current and details and some results from the work plan are discussed