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Ventilation System

Rini Novrianti Sutardjo Tui

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Elements of VentilationInfrastructure

Directionof airflow

Layout ofthe

airwaynetwork

Positionsand

duties offans

Geometryof theairway

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Airflow Direction

Direction

Ascentional

Up dipthrough

Homotropal

Moves indirection

Descentional

Downdip

through

Antitropal

Movesopposite

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Ventilation Layouts

U Tube Through Flow

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Brattice System

Brattice is pinned to the floor and back and supported by a frame, typicallyone-quarter to one-third from the nearest rib. Most common application is in

room and pillar systems.

Advantages

Low initialcapital cost

Doesnt need

additionalpower

Produces nosignificant

noise

Disadvantages

Addssignificantly to

the overallmine

ventilationsystem

resistance

Under bestcases only

about 1/3 ofthe total air

availablemakes it to theworking face

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Fan and Duct System

Advantages

Providesbetter control

of airflow atthe face

Doesnt add to

the overall mineventilation

system resistance

The onlypractical solution

for distances over30 m

Disadvantages

Higherinitial

capital cost

Electricpower mustbe suppliedat the fans

Duct

systemstake space

Fannoise

Most often, axial flowfans are used, but

centrifugal can be used.When using exhaustingtype systems, allows the

air to be filtered.

Axial Flow Fan

Centrifugal Flow Fan

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Ventilation Fans

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Forcing System

Advantages

Possible to use flexible ducting

Cheaper and easier to handle

Leaks are more easily detected andrepaired

Disadvantage

Pollutants move relatively slowlythrough the heading

In the forcing system, the faninlet is open to the atmosphereand the fan outlet to the mine

intake shaft.

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Exhausting System

A solution wheredust is a concern,since the pollutantsare drawn directlyinto the ventilatingduct

Advantage

Can result in poormixing of air

Re-circulating airmay develop

Disadvantages

In the exhausting system, the fan inlet

is open to the mine through the returnshaft, and the fan outlet is open to the

atmosphere.

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Extended System

AuxiliarySystem

When auxiliary system isused in extended entries, the resistance of theduct can become so high that multiple fans mustbe used.

BestApproach

The best approach is to separate thefans along the length of the duct to avoid excesspressure.

MultipleFans

Multiple fans should be interlocked toprevent the possibility of uncontrolledrecirculation.

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Overlapping System

Advantages

Greater flexibility tocontrol

Better control ofpressure and leakage

Diadvantages

More expensive(capital andoperating)

More subjects tomiss-handling

A common methodof combining forcing

and exhaustingsystem

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