The characteristic given below refers to a main fan running at 8 rev/s and moving air with a density of 1.0 kg/m3. The fan is to be installed underground, operating against a mine resistance of 0.067 Ns2/m8, and will handle air at a density of 1.2 kg/m3. A natural ventilation pressure of 250 N/m2 assists the fan. Noting that mine airway friction factor, K, varies with air density, determine (i) the speed at which the fan must run to give a volume flow rate of 165 m3/s; (ii) the pressure produced by the fan at the new speed. Fan characteristic Volume flow rate, m3/s 50 80 100 125 150 175 Fan pressure, N/m2 1300 1375 1325 1190 985 730
The characteristic given below refers to a main fan running at 8 rev/s and moving air with a density of 1.0 kg/m3. The fan is to be installed underground, operating against a mine resistance of 0.067 Ns2/m8, and will handle air at a density of 1.2 kg/m3. A natural ventilation pressure of 250 N/m2 assists the fan.
Noting that mine airway friction factor, K, varies with air density, determine
(i) the speed at which the fan must run to give a volume flow rate of 165 m3/s;
(ii) the pressure produced by the fan at the new speed.
Fan characteristic
Volume flow rate, m3/s 50 80 100 125 150 175
Fan pressure, N/m2 1300 1375 1325 1190 985 730
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