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VENTILASI TAMBANG

2 Desember 2014 Hendra Harisman, ST., M.Eng.

JTP 505 2 SKS


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OUTLINES

FAN PERFORMANCE AND FAN LAWS

Fan operating point

Laws relating fan speed and density

Fans in parallel and series combinations

Correction for natural ventilation pressure

Fan performance control methods

Comparison of fan types and specific speed

Noise


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OUTLINES


Fan operating point






Noise


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Fans in Parallel and Series Combinations

Fans are connected in series and parallel for a numapplications.

For main surface or underground booster fans, methe required duty with two or more fans in parallelprovides security in the event of a single unit failuremaintenance.

Increasing the size of a single fan to accommodatair volumes may incur disproportionate casing faband foundation cost.


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Consider 2 fans A & B connectedin series.

The same quantity passes through both fans but the pressu

developed is given by the sum of that due to each fan,P = PA + PB

The method of calculation is to generate a combined fan summing the fan pressure at each quantity point.

SERIES


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P = PA + PB

Q = QA

= QB

The operating poingiven by the interseof the system resistcurve and the comfan curve.


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Consider 2 fans A & B connectedin parallel.

In parallel combination, the pressure drop across both fans

same with the quantity through each unit determined by itcharacteristic curve.

The fans do not necessarily have to be the same, but shousimilar duty.

PARALLEL


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P = PA = PB

Q = QA + QB


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Fan Operating Point

A fans characteristic curve is described by the following Pdata points.

Plot kurva karakteristik kipas, aada 2 kipasyang sama disususeri.

Plot kurva karakteristik kipas, a

ada 2 kipasyang sama disusuparallel.


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Fan Operating Point


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Fan Operating Point


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Fan Operating Point


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Fan Operating Point


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OUTLINES


Fan operating point






Noise


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Correction for Natural Ventilation Pressure

The natural ventilation pressure in a mine ventilation cdetermined by the depth of workings and difference b

average intake (downcast) and average exhaust (updensity.

Heating of air within the mine results in exhaust air beinand therefore less dense, than that in the intakes.

Consequently, NVP normally acts in the direction of ai

and acts to assist surface fans.


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Effect of NVP on fan operating point.


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Contoh:

R =0.034 Ns

2

/m

8

NVP = 350 Pa

Fan operating point = ???

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