Page 98 - Advanced Mine Ventilation

Mechanical and Natural 6

Ventilation

Chapter Outline

6.1 Radial Flow Fans 80
6.1.1 Head Developed by Radial Bladed Fans 80
6.1.2 Backward Bladed Fans 82
6.1.3 Forward Bladed Fans 82
6.1.3.1 Frictional and Shock Losses 83
6.1.3.2 Conversion Losses 83
6.1.3.3 Recirculation 83
6.1.3.4 Bearing Friction 84
6.1.3.5 Fan Efficiency 84
6.2 Fan Characteristics 84
6.3 Axial Flow Fans 84
6.3.1 Performance Characteristics of an Axial Flow Fan 85
6.4 Fan Laws 86
6.5 Fan Testing 87
6.5.1 Air Quantity 87
6.5.2 Total and Static Pressures 87
6.5.3 Air Density 87
6.5.4 Fan Speed 87
6.5.5 Fan Shaft Horsepower 88
6.5.6 Air Horsepower 88
6.6 Matching a Fan to Mine Characteristics 88
6.7 Natural Mine Ventilation 89
6.7.1 Historical Review of Natural Ventilation Pressure Calculations 90
6.7.1.1 Weeks Method 90
6.7.1.2 McElroy Method 91
6.7.1.3 Rees Method 91
6.7.1.4 Hinsley Method 91
Problems 91
References 92

In the old days, mines were mostly naturally ventilated. Temperature differences
induced air flow, but it was not reliable. People used furnaces in the upcast shafts to
induce air flow or forced air in the downcast shafts with bellows or paddle wheels oper-
ated by wind, hydropower, or animals. Mechanical ventilation using fans developed
during the second half of the 19th century to replace all old unreliable devices. The
early fans were of simple radial flow design, which were gradually improved as expe-
rience was gained. Backward and forward bladed radial flow fans were widely used.

Advanced Mine Ventilation. https://doi.org/10.1016/B978-0-08-100457-9.00006-7
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