Subsurface Ventilation and Environmental Engineering

912 Pages·1993·17.838 MB·English

by  Malcolm J. McPherson (auth.)

Subsurface Ventilation
and
Environmental
Engineering
Subsurface Ventilation
and
Environmental
Engineering
Malcolm J. McPherson
The Massey Professor of Mining Engineering,
Virginia Polytechnic Institute and State University
and
President,
Mine Ventilation Services,
Incorporated
USA
m
SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.
First edition 1993
© 1993 Malcolm J. McPherson
Originally published by Chapman & Hall in 1993
Softcover reprint of the hardcover 1 st edition 1993
Typeset in 10/12 pt Bembo by Thomson Press (India) Limited, New Delhi, India
ISBN 978-94-010-4677-0 ISBN 978-94-011-1550-6 (eBook)
DOI 10.1007/978-94-011-1550-6
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The publisher makes no representation, express or implied, with regard to
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A catalogue record for this book is available from the British Library
Library of Congress Cataloging-in-Publication Data
McPherson, Malcolm J.
Subsurface ventilation and environmental engineering / Malcolm J.
McPherson. — 1st ed.
p. cm.
Includes bibliographical references and index.
1. Mine ventilation. 2. Air—Pollution. 3. Mine fires. 4. Mine
explosions. 5. Underground areas—heating and ventilation.
6. Underground areas—Fires and fire prevention. 7. Explosions.
I. Title.
TN301.M37 1992
622'.42—dc20 92-6185
CIP
This work has been undertaken in fulfilment of
a long-standing promise to my former teacher,
mentor and dear friend
Professor Frederick Baden Hinsley
The book is dedicated to his memory
Contents
Acknow ledgements xiii
Preface xv
Unit conversion table xvii
1 Background to subsuiface ventilation and environmental engineering 1
1.1 Introduction 1
1.2 A brief history of mine ventilation 1
1.3 The relationships between ventilation and other subsurface systems 8
Further reading 10
PART ONE Basic Principles of Fluid Mechanics and Physical 13
Thermodynamics
2 Introduction to fluid mechanics 15
2.1 Introduction 15
2.2 Fluid pressure 17
2.3 Fluids in motion 23
Further reading 48
3 Fundamentals of steady flow thermodynamics 50
3.1 Introduction 50
3.2 Properties of state, work and heat 51
3.3 Some basic relationships 54
3.4 Frictional flow 66
3.5 Thermodynamic diagrams 76
Further reading 87
P ART TWO Subsuiface Ventilation Engineering 89
4 Subsuiface ventilation systems 91
4.1 Introduction 91
V111 Contents
4.2 Mine systems 91
4.3 District systems 102
4.4 Auxiliary systems 111
4.5 Controlled partial recirculation 119
4.6 Underground repositories 129
Further reading 132
5 Incompressible flow relationships 134
5.1 Introduction 134
5.2 The Atkinson equation and the square law 134
5.3 Determination of friction factor 136
5.4 Airway resistance 141
5.5 Airpower 160
A5 Shock loss factors for airways and ducts 161
Further reading 173
6 Ventilation surveys 175
6.1 Purpose and scope of ventilation surveys 175
6.2 Air quantity surveys 176
6.3 Pressure surveys 193
6.4 Organization of pressure-volume surveys 204
6.5 Air quality surveys 207
Further reading 207
7 Ventilation network analysis 209
7.1 Introduction 209
7.2 Fundamentals of ventilation network analysis 211
7.3 Methods of solving ventilation networks 214
7.4 Ventilation network simulation packages 230
References 239
Further reading 239
8 Mine ventilation thermodynamics 241
8.1 Introduction 241
8.2 Components of the mine cycle 242
8.3 The complete mine cycle 258
Further reading 281
9 Ventilation planning 282
9.1 Systems analysis of the planning procedure 282
9.2 Establishment of the basic network 284
9.3 Airflow requirements and velocity limits 287
9.4 Planning exercises and time phases 295
9.5 Ventilation economics and airway sizing 299
9.6 Booster fans 312
9.7 Traditional method of ventilation planning 319
References 321
Further reading 321
Contents IX
10 Fans 322
10.1 Introduction 322
10.2 Fan pressures 323
10.3 Impeller theory and fan characteristic curves 326
10.4 Fan laws 343
10.5 Fans in combination 347
10.6 Fan performance 349
AlO Derivation of the isentropic temperature-pressure relationship
for a mixture of air, water vapour and liquid water droplets 361
References 364
Further reading 365
P ART THREE Gases in the Subsuiface 367
11 Gases in subsuiface openings 369
11.1 Introduction 369
11.2 Classification of subsurface gases 370
11.3 Gas mixtures 384
11.4 Gas detection and monitoring 390
References 400
Further reading 400
12 Methane 401
12.1 Overview and additional properties of methane 401
12.2 The retention and release of methane in coal 402
12.3 Migration of methane 414
12.4 Emission patterns into mine workings 425
12.5 Methane drainage 436
References 454
Further reading 456
13 Radiation and radon gas 457
13.1 Introduction 457
13.2 The uranium series and radioactive decay 458
13.3 Radon and its daughters 463
13.4 Prediction oflevels of radiation 470
13.5 Methods of monitoring for radiation 475
13.6 Control of radiation in subsurface openings 477
References 486
P ART FOUR Heat and Humidity 489
14 Psychrometry: The study of moisture in air 491
14.1 Introduction 491
14.2 Basic relationships 492
14.3 The measurement of water vapour in air 501
x Contents
14.4 Theory of the wet bulb thermometer 504
14.5 Further psychrometric relationships 508
14.6 Summary of psychrometric equations 512
14.7 Deviations from classical theory 514
14.8 Psychrometric charts 516
A14 Derivation of the Clausius-Clapeyron equation 519
References 520
Further reading 521
15 Heat flow into subsurface openings 522
15.1 Introduction 522
15.2 Strata heat 522
15.3 Other sources of heat 553
References 571
Further reading 571
A15 Appendices: Mathematical background 572
A15.1 Solution of the three-dimensional transient heat conduction
equation (15.13) as obtained by Carslaw and Jaeger 572
A15.2 Gibson's algorithm for computation of dimensionless
temperature gradient, G 572
A15.3 Background to equations for the heat transfer coefficient 572
A15.4 Derivation of the equation for latent heat of evaporation
at a wet surface 578
16 Simulation of climatic conditions in the subsurface 583
16.1 Background 583
16.2 Elements of mine climate simulation programs 584
16.3 Using a mine climate simulator 591
References 601
Further reading 602
17 Physiological reactions to climatic conditions 603
17.1 Introduction 603
17.2 Thermoregulation of the human body 603
17.3 Physiological heat transfer 605
17.4 Indices of heat stress 625
17.5 Heat illnesses 633
17.6 Cold environments 637
17.7 Heat tolerance, acclimatization and variation ofp roductivity with 640
mine climate
References 645
Further reading 646
A17 Listing of the thermoregulation model developed in
section 17.3 647
Contents Xl
18 Refrigeration plant and mine air conditioning systems 651
18.1 Introduction 651
18.2 The vapour compression cycle 652
18.3 Components and design of mine cooling systems 666
18.4 Air heating 727
References 736
Further reading 738
PART FIVE Dust 739
19 The hazardous nature of dusts 741
19.1 Introduction 741
19.2 Classifications of dust 742
19.3 Dust in the human body 744
19.4 The assessment of airborne dust concentrations 753
References 763
20 The aerodynamics, sources and control of airborne dust 765
20.1 Introduction 765
20.2 The aerodynamic behaviour of dust particles 765
20.3 The production of dust in underground openings 782
20.4 Control of dust in mines 790
References 809
PAR T SIX Fires and Explosions 813
21 Subsuiface fires and explosions 815
21.1 Introduction 815
21.2 Causes of ignitions 817
21.3 Open fires 821
21.4 Spontaneous combustion 833
21.5 Stoppings, seals and section pressure balances 847
21.6 The use of inert gases 853
21.7 Fire gases and their interpretation 857
21.8 Explosions 868
21.9 Protection of personnel 877
21.10 Emergency procedure and disaster management 885
References 887
Further reading 890
Index 891
Acknow ledgements
There are many people without whose contributions this book could not have been
written. First, I thank Shirley, my wife, for her patience and understanding-not
only through the long hours of midnight oil burning that took place during the
writing but, more particularly, for the extended periods, stretching over many years,
when she was left alone to look after the home and family while I was deep under
the surface of some faraway country.
I am grateful to former colleagues in the Department of Mining Engineering,
University of Nottingham, England, for sowing seeds of ideas that later produced
practical designs and procedures, many of which are reflected in this book; especially
Ian Longson with whom I rediscovered the fascinations of thermodynamic logic,
Leslie H. Morris, Dr. Jim R. Brown and, most of all, Professor F. Baden Hinsley to
whom this book is dedicated. I am also privileged in having worked with excellent
students from whom I learned a great deal, at Nottingham, at the University of
California, Berkeley, and now at Virginia Polytechnic and State University.
Despite having been involved in numerous research investigations, my knowledge
ofs ubsurface ventilation and environmental engineering has been advanced primarily
by working on projects with mine ventilation engineers in many countries. Most of
the case studies and examples in the book originated in such work. In particular, I
am truly grateful for having had the opportunity of interacting with dedicated
professional engineers in the United Kingdom, the countries of East and West Europe,
South Africa, Australia, India, the United States of America and Canada.
I am indebted to the two ladies who shared typing the manuscript. First, my
daughter Alison D. McPherson who also took great delight in correcting some of
my mathematics, and, Lucy Musante, my secretarial assistant at Mine Ventilation
Services, Inc.-the most skilled and dedicated secretary with whom I have ever
worked. Most of the initial reviews of chapters were undertaken by staff of Mine
Ventilation Services, namely Daniel J. Brunner, Justus Deen, Martha O'Leary and,
most particularly, Keith G. Wallace who willingly volunteered for far more than his
fair share of the work. Several chapters were reviewed by Dr. Felipe Calizaya,
formerly at Berkeley and now at the Mackay School of Mines in Reno, Nevada.