An Introduction to Dust Explosions

Preventable dust explosions continue to occur in industry in spite of significant research and practice efforts worldwide over many years. There is a need for effective understanding of the unique hazards posed by combustible dust. This book describes a number of dust explosion myths – which together cover the main source of dust explosion hazards – the reasons they exist and the corresponding scientific and engineering facts that mitigate these circumstances.

An Introduction to Dust Explosions describes the main erroneous beliefs about the origin and propagation of dust explosions. It offers fact-based explanations for their occurrence and the impact of such events and provides a critical guide to managing and mitigating dust explosion risks.

• Designed to prevent accidents, injury, loss of life and capital damage
• An easy-to-read, scientifically rigorous treatment of the facts and fictions of dust explosions for those who need to – or ought to – understand dust explosions, their occurrence and consequences
• Enables the management and mitigation of these critical industrial hazards

Process Engineers, Safety Engineers, Chemical Engineers, Mechanical Engineers in the Process Industries, Managers in the Process Industries, Safety Consultants.

Dedication

Preface

Author

Chapter 1. Introduction: Dust Explosions—Myth or Reality?

1.1 Explosion Pentagon

1.2 Dust Explosion Myths

1.3 Why this Book?

1.4 What do You Think?

References

Chapter 2. Myth No. 1 (Fuel): Dust Does Not Explode

2.1 Dust Definition

2.2 Determination of Dust Explosibility

2.3 An Explosible Non-Explosible Dust

2.4 Reality

2.5 What do You Think?

References

Chapter 3. Myth No. 2 (Fuel): Dust Explosions Happen Only in Coal Mines and Grain Elevators

3.1 Cyclical Interest in an Ever-Present Problem

3.2 Magnitude of the Problem

3.3 Reality

3.4 What do You Think?

References

Chapter 4. Myth No. 3 (Fuel): A Lot of Dust Is Needed to Have an Explosion

4.1 Guidance from Physics and Chemistry

4.2 Practical Guidance

4.3 Housekeeping

4.4 Reality

4.5 What do You Think?

References

Chapter 5. Myth No. 4 (Fuel): Gas Explosions Are Much Worse Than Dust Explosions

5.1 Hazard and Risk

5.2 Example: Likelihood of Occurrence and Prevention

5.3 Example: Severity of Consequences and Mitigation

5.4 Hybrid Mixtures

5.5 Reality

5.6 What do you Think?

References

Chapter 6. Myth No. 5 (Fuel): It’s Up to the Testing Lab to Specify Which Particle Size to Test

6.1 Role of Particle Size Distribution

6.2 Particle Size Effects on Explosibility Parameters

6.3 A Cooperative Endeavor

6.4 Reality

6.5 What do You Think?

References

Chapter 7. Myth No. 6 (Fuel/Ignition Source): Any Amount of Suppressant Is Better Than None

7.1 Inerting and Suppression

7.2 Minimum Inerting Concentration

7.3 Suppressant Enhanced Explosion Parameter

7.4 Thermal Inhibitors

7.5 Reality

7.6 What do you Think?

References

Chapter 8. Myth No. 7 (Ignition Source): Dusts Ignite Only with a High-Energy Ignition Source

8.1 Industrial Ignition Sources

8.2 Standardized Dust Explosibility Testing

8.3 Dust Cloud Ignition by Low-Energy Sources

8.4 Reality

8.5 What do you Think?

References

Chapter 9. Myth No. 8 (Ignition Source): Only Dust Clouds—Not Dust Layers—Will Ignite

9.1 Dust Layer Ignition

9.2 Dust Layer Fires

9.3 Reality

9.4 What do you Think?

References

Chapter 10. Myth No. 9 (Oxidant): Oxygen Removal Must Be Complete to Be Effective

10.1 Limiting Oxygen Concentration

10.2 Candidate Inert Gases

10.3 Reality

10.4 What do you Think?

References

Chapter 11. Myth No. 10 (Oxidant): Taking Away the Oxygen Makes Things Safe

11.1 Nothing is Safe

11.2 Introduction of New Hazards

11.3 Management of Change

11.4 Reality

11.5 What do you Think?

References

Chapter 12. Myth No. 11 (Mixing): There’s No Problem If Dust Is Not Visible in the Air

12.1 Primary and Secondary Dust Explosions

12.2 Domino Effects

12.3 Reality

12.4 What do you Think?

References

Chapter 13. Myth No. 12 (Mixing): Once Airborne, a Dust Will Quickly Settle out of Suspension

13.1 Dustiness

13.2 Preferential Lifting

13.3 Nano-Materials

13.4 Flocculent Materials

13.5 Reality

13.6 What do you Think?

References

Chapter 14. Myth No. 13 (Mixing): Mixing Is Mixing; There Are No Degrees

14.1 Turbulence

14.2 Influence of Turbulence

14.3 Concentration Gradients

14.4 Reality

14.5 What do you Think?

References

Chapter 15. Myth No. 14 (Confinement): Venting Is the Only/Best Solution to the Dust Explosion Problem

15.1 Inherently Safer Design

15.2 Hierarchy of Controls

15.3 Dust Explosion Prevention and Mitigation Measures

15.4 Reality

15.5 What do you Think?

References

Chapter 16. Myth No. 15 (Confinement): Total Confinement Is Required to Have an Explosion

16.1 Degree of Confinement

16.2 Explosion Relief Venting

16.3 Reality

16.4 What do you Think?

References

Chapter 17. Myth No. 16 (Confinement): Confinement Means Four Walls, a Roof, and a Floor

17.1 Congestion and Obstacle-Generated Turbulence

17.2 Temporary Enclosures

17.3 Reality

17.4 What do you Think?

References

Chapter 18. Myth No. 17 (Pentagon): The Vocabulary of Dust Explosions Is Difficult to Understand

18.1 Dust Explosion Terminology

18.2 Gas Explosion Analogies

18.3 Right to Know

18.4 Reality

18.5 What do you Think?

References

Chapter 19. Myth No. 18 (Pentagon): Dust Explosion Parameters Are Fundamental Material Properties

19.1 A Quiescent Dust Cloud—The (Nearly) Impossible Dream

19.2 The Mystical KSt Parameter

19.3 Standardized Dust Explosibility Testing (Revisited)

19.4 Reality

19.5 What do you Think?

References

Chapter 20. Myth No. 19 (Pentagon): It Makes Sense to Combine Explosion Parameters in a Single Index

20.1 USBM Indices

20.2 Assessment and Management of Dust Explosion Risks

20.3 Material Safety Data Sheets

20.4 Reality

20.5 What do you Think?

References

Chapter 21. Myth No. 20 (Pentagon): It Won’t Happen to Me

21.1 Safety Culture

21.2 Safety Management Systems

21.3 Westray Coal Mine Explosion

21.4 Reality

21.5 What do you Think?

References

Chapter 22. Conclusion: Dust Explosion Realities

22.1 Myths and Corresponding Realities

22.2 What do you Think?

References

Index