Chapter 6
Fans and Flow Control Devices
6.1 Introduction
So far, indications have been given of the general movement of air within the mine.
However, little has been said about how this movement is induced or how airflow is
redirected to specific areas where it is most needed or reduced in others. Fans handle
the former and the latter is achieved using airflow control devices. This chapter
introduces the reader to the principles of operation and sizing of both systems.
6.2 Fans
A fan is a type of turbomachine,
1 which continuously expels air and increases its
kinetic energy and pressure. In the past, the volumetric machines (operating by
strokes) were common, but at present, their use is null for mine ventilation purposes,
being reserved for the production of compressed air for mining equipment actuation.
The main purpose of a fan is to generate a high air quantity at a pressure higher than
the atmospheric, but not much higher. This makes it possible to consider the air as
incompressible which means that their compression ratio is <1.15. Fans differ from
compressors, as the latter generate much smaller flow rates but at a much higher
pressure.
1 Machine capable of exchanging energy with a fluid through the movement of a rotating wheel,
usually termed rotor.
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Switzerland AG 2020
C. Sierra, Mine Ventilation, https://doi.org/10.1007/978-3-030-49803-0_6
195
Fans and Flow Control Devices
6.1 Introduction
So far, indications have been given of the general movement of air within the mine.
However, little has been said about how this movement is induced or how airflow is
redirected to specific areas where it is most needed or reduced in others. Fans handle
the former and the latter is achieved using airflow control devices. This chapter
introduces the reader to the principles of operation and sizing of both systems.
6.2 Fans
A fan is a type of turbomachine,
1 which continuously expels air and increases its
kinetic energy and pressure. In the past, the volumetric machines (operating by
strokes) were common, but at present, their use is null for mine ventilation purposes,
being reserved for the production of compressed air for mining equipment actuation.
The main purpose of a fan is to generate a high air quantity at a pressure higher than
the atmospheric, but not much higher. This makes it possible to consider the air as
incompressible which means that their compression ratio is <1.15. Fans differ from
compressors, as the latter generate much smaller flow rates but at a much higher
pressure.
1 Machine capable of exchanging energy with a fluid through the movement of a rotating wheel,
usually termed rotor.
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Switzerland AG 2020
C. Sierra, Mine Ventilation, https://doi.org/10.1007/978-3-030-49803-0_6
195