Page 9 - Advanced Mine Ventilation

viii Contents

3.7 Concentration Growth in a Roadway With Uniformly
Distributed Source 41
Problems 41
References 42

4 Estimation of Ventilation Air Quantity 43
4.1 The Modern Mine Layout 44
4.2 Methane Emissions 45
4.3 Mildly Gassy Coal Seams 48
4.4 Moderately Gassy Coal Seams 49
4.5 Very Gassy Coal Seams 49
4.6 Limitations on the Longwall Face Width Owing to Face Methane
Emissions 51
4.7 Limitations on the Longwall Face Width Owing to Gob Methane
Emissions 54
4.8 Air Quantity Requirements for Development Headings 56
4.9 Estimation of Total Required Ventilation Air 56
4.10 Standards of Volumetric (Ventilation) Efficiency 58
Problems 59
References 59

5 Ventilation Network Analysis 61
5.1 Network Analysis for Air Quantities and Pressure 63
5.2 Introduction to the Ventilation Network Analyzer 67
5.3 Verification of the Ventilation Network Analyzer in a Working Mine 68
Problems 77
References 77

6 Mechanical and Natural Ventilation 79
6.1 Radial Flow Fans 80
6.2 Fan Characteristics 84
6.3 Axial Flow Fans 84
6.4 Fan Laws 86
6.5 Fan Testing 87
6.6 Matching a Fan to Mine Characteristics 88
6.7 Natural Mine Ventilation 89
Problems 91
References 92

Section Two Respirable Coal Dust Control

7 Health Hazards of Respirable Dusts 95
7.1 Growth of Coal Workers’ Pneumoconiosis 95
7.2 A Basis for Respirable Dust Standard 101
7.3 Prevalence and Cessation of Coal Workers’ Pneumoconiosis 101
7.4 Lifestyle Intervention Program 103
References 104