VENTILATION
SYSTEM
EM 165: Mine Ventilation
MSU-IIT
COE
VENTILATION SYSTEM
Every UG mine is unique
Classification:
 Mine systems
 District systems
 Auxiliary ventilation systems
VENTILATION SYSTEM: MINE SYSTEM
 Fresh air enters via downcast shafts or other surface connections.
 Air flows along intake airways to working areas where most pollutants are added.
 Contaminated air returns back through the system along return airways.
 The return air passes back up to the surface via upcast shafts or other surface return
connections.
VENTILATION SYSTEM: MINE SYSTEM
Passive
Device
Area of Less
Resistance
 Air
Airflow
Control Device
Active
Device
Area of High
Resistance
Area usually
needs ventilation
VENTILATION SYSTEM: MINE SYSTEM
Active Devices: adds energy to air to direct it to where it is
needed
 Main Fan: primary means of producing and controlling
the ventilation airflow; usually located near the surface
Types of main
fan systems:
VENTILATION SYSTEM: MINE SYSTEM
Active Devices: Main Fan
Exhausting vs. Forcing Fan System
 Gas control (control during falls of barometer and fan stoppage
favors exhausting)
 Transportation (selection depends on whether transporting
mineral through intake or return airways)
 Fan maintenance (exhaust fan subjected to air carrying dust,
warmer air, and water droplets, thus the combined effects of
impaction and corrosion are greater than in forcing case)
 Fan performance (cooler air implies lower mass flow duty for a
forcing fan and hence for a certain airflow, a reduced pressure
and running costs). However, this effect is usually not great.
VENTILATION SYSTEM: MINE SYSTEM
Active Devices: Main Fan
Push-Pull Fan System
For metalliferous mine employing caving technique
Employed in multi-shaft mines for better distribution of
airflow, greater flexibility, better control over pressure and
leakage, reduced operating cost.
VENTILATION SYSTEM: MINE SYSTEM
Active Devices: Main Fan
Advantages:
1.
2.
3.
4.
5.
Simpler Installation
Simpler Testing
Simpler Maintenance
Easier Access
Better Protection in
Emergency Situation
VENTILATION SYSTEM: MINE SYSTEM
Active Devices: Main Fan
VENTILATION SYSTEM: MINE SYSTEM
Active Devices
 Booster Fan: employed
when air flows through a
ventilation network loses
energy.
Advantages:
 No need to upgrade existing main fan facilities, avoiding
capital and operating cost increases; and
 Only a proportion of the whole mine airflow is boosted,
saving operational costs compared to having to boost the
whole mine airflow.
VENTILATION SYSTEM: MINE SYSTEM
Passive Devices: add resistance to flow routes to encourage
the air to flow along other routes
VENTILATION SYSTEM: MINE SYSTEM
Passive Devices: add resistance to flow routes to encourage
the air to flow along other routes
VENTILATION SYSTEM: MINE SYSTEM
Passive Devices: add resistance to flow routes to encourage
the air to flow along other routes
 Air Doors and Airlocks: employed to minimize shortcircuiting of
ventilation flow by
increasing resistance
of a potential shortcircuit route
VENTILATION SYSTEM: MINE SYSTEM
Passive Devices: add resistance to flow routes to encourage
the air to flow along other routes
 Regulators: an air door
fitted with an adjustable
orifice for reduction of
airflow in a particular
section downstream to a
defined airflow by increasing
the resistance of the airway
VENTILATION
SYSTEM:
MINE SYSTEM
Passive Devices:
Regulators
VENTILATION SYSTEM: MINE SYSTEM
Passive Devices: add resistance to flow routes to encourage
the air to flow along other routes
 Air crossing: installed where intake and return airways
need to cross over each other
Forms:
Natural
Intersection
Prefabricated
VENTILATION SYSTEM: MINE SYSTEM
Passive Devices: Air crossing
Types:
Overcast: roof is ripped over one of the galleries, two
chambers constructed and one of the air currents, usually
the return is made to go via top chamber.
Undercast: the floor-dug up to make the two chamber, and
one of the air currents, usually the return, is made to flow
through the lower chamber.
VENTILATION SYSTEM: MINE SYSTEM
Passive Devices:
Stoppings: blockage placed between intake and return
airways which was previously used to provide quick access
but no longer required
Seals: constructed to prevent unwanted
air loss from a ventilation system and to
preclude oxygen from entering mined-out
areas to prevent spontaneous combustion