Ignition sources : fire, explosion and detonation / K. Ramamurthi.

Format:

Book

Author/Creator:

Ramamurthi, K., author.

Language:

English

Subjects (All):

Explosions.

Fire.

Fire prevention.

Physical Description:

1 online resource (206 pages)

Place of Publication:

Cham, Switzerland : Springer, [2023]

Summary:

This book discusses the different energy sources bringing about fires, explosions, and detonations in combustibles under different levels of confinement. Focus is on the initiation source for a combustible whether it is a gas, a liquid, or a solid in a given state of confinement. Incidents of oxygen-related fires in hospitals which were particularly evident with increased usage of oxygen therapy for the extremely ill COVID-19 patients in 2021 are discussed with details of formation, accumulation, and dissipation of charges and their discharges leading to fires and explosions. Sympathetic detonations, BLEVE explosions, cook-off tests of combustibles, the inadvertent ignition sources (threats), and their control are discussed. Sporadic Ignition of wildfires in a heat dome augmented by the reflection of expansion disturbances from the interfaces separating media of different acoustic impedances are explored. Spontaneous human combustion, pilot ignition, shock wave ignition, ignition of fuel droplets and conditions under which fires, explosions, and detonations take place are discussed. Different ways of mitigating the inadvertent initiation of explosions and detonations are given at the end.

Contents:

Intro

Preface

Contents

Nomenclature

Greek Symbols

Subscripts

Superscripts

1 Preliminary Concepts and Introduction

1.1 Ignition Sources for Fire, Explosion, and Detonation

1.1.1 Energy Requirements

1.1.2 Fire, Explosion, and Detonation

1.1.3 Fire Triangle

1.1.4 Combustible: Fuel, Oxidizer, Explosive and High-Energy Material

1.1.5 Concentration Limits of Fuel and Oxygen to Form Fire

1.1.6 Confinement of Combustible

1.1.7 Activation Energy and Rate of Heat Release

1.1.8 Magnitudes of Energy Release

1.1.9 Ignition Sources

1.2 Initiation of Chemical Reactions for Fire, Explosion, and Detonation

1.3 Energy for Initiation

1.4 Phonons in the Initiation Process

1.5 Size of Energy Source

1.6 Classification of Ignition Sources

2 Thermal Ignition Energy Sources

2.1 Introduction

2.2 Mechanical Spark

2.2.1 Friction Spark

2.2.2 Sparks During Grinding

2.2.3 Assessment of Energy

2.2.4 Incendiaries and Molten Metal

2.2.5 Energy Content of Spark and Energy Required for Ignition

2.3 Hot Surfaces

2.3.1 Hot Surface and Auto-Ignition

2.3.2 Hot Surfaces from Friction

2.3.3 Solar, Electrical, Radiation, and Space Heating Contributing to Hot Surface

2.3.4 Forced Convection Heat Transfer to Combustibles from Hot Surfaces

2.4 Flame for Ignition

2.4.1 Size of Flame to Start Fire

2.4.2 Size of Candle and Explosions in Coal Mines in the Days of Faraday

2.5 Friction at Surfaces

2.6 Adiabatic Compression

2.7 Shock Compression

2.8 Thermal Initiation by Impact

2.8.1 Low-Velocity Impact

2.8.2 High-Velocity Impact

2.9 Resonant Heating

2.10 Electrical Energy Contributing to Heat

2.10.1 Resistive Heating

2.10.2 Arc Heating

2.10.3 Peltier Heating

3 Chemical Ignition Energy Sources

3.1 Introduction

3.2 Ignition by Catalytic Reactions.

3.3 Catalyst Bed as Ignition Source

3.4 Catalysts as Accidental Ignition Sources for Fires and Explosions

3.5 Thermite Reactions as Ignition Sources

3.6 Hypergolic and Pyrophoric Reactions

3.6.1 Pyrophoric Reactions and Difference from Hypergolic Reactions

3.6.2 Hypergolic Liquid Fuels and Oxidizers

3.6.3 Mechanism of Hypergolic Ignition

3.6.4 Other Hypergolic Combinations

4 Electrostatic Ignition Energy Sources

4.1 Introduction: Charges, Discharges, and Energy Release

4.2 Formation of Charges

4.2.1 Contact at Interface

4.2.2 Relative Motion of Interface: Rubbing and Sieving

4.2.3 Inductive Charging

4.2.4 Transfer of Charge

4.2.5 Formation of Charge During Fragmentation and Micronizing

4.2.6 Charge Formation from Piezo-Electric Effect

4.3 Charge and Electric Field

4.4 Ability of Combustible to Retain Charge: Permittivity

4.4.1 Units of Permittivity

4.5 Movement of Charges: Current Density, Mobility, and Specific Electrical Conductivity

4.6 Characteristic Time for Charge to be Retained: Relaxation Time

4.7 Different Types of Discharges

4.8 Breakdown and Paschen's Law

4.9 Charge Accumulation in the Flow of Insulating Liquid and Gaseous Combustibles

4.10 Electrical Discharge from Accumulated Charge in Flow of Combustible

4.11 Streaming Current

4.11.1 Charge Accumulation with Streaming Currents from Multiple Inlets and Outlets

4.12 Charge Accumulation in Humans

4.13 Energy During Discharge

5 Shock Waves as Ignition Sources

5.1 Shock Waves Initiating Detonation

5.2 Objects Moving at Supersonic and Hypersonic Velocities

5.3 Merging of Compression Waves to Form Shocks

5.4 Exploding Wires and Shock Formation

5.5 Exploding Foil and Slapper

6 Electromagnetic Radiation Ignition Sources

6.1 Electromagnetic Waves.

6.2 Electromagnetic Spectrum: Energy per Photon

6.2.1 Microwave Heating

6.2.2 Infrared Heating

6.2.3 Heating in Visible and Ultraviolet

6.2.4 X-Rays and Gamma Rays

6.3 Laser and Plasmonic Energy Absorption

7 Ignition Sources for Fire and Explosions in Solid Combustibles

7.1 Solid Fuels and Explosives

7.2 Initiation of Fire and Smolder in Solid Combustibles

7.2.1 Role of Heat Losses in the Initiation of a Fire: Confinement

7.2.2 High-Pressure Heat Dome

7.2.3 Ambient Pressure

7.3 Hypergolic Ignition of Solid Fuel

7.4 Ignition by Mechanical Work

7.5 Ignition of Solid Explosives

7.6 Confinement and Role of Heat Losses in the Ignition of Explosives

7.7 Heated Wire as Ignition Source

7.8 Intrinsic Energy Sources in the Condensed Phase

7.9 Pyrotechnics and Ignition

7.10 Strong and Weak Ignition

7.11 Influence of Confinement

7.12 Partial Confinement and Propellant Ignition

7.12.1 Ignition Source for a Rocket

7.12.2 Full Confinement for Ignition

7.13 Configuration of Ignition Source

7.14 Hang-Fire from Deficient Ignition Source

7.15 Ignition System for a Cartridge

7.16 Ignition Systems for Grenades, Shells, and Mortars

7.17 Thermal Response of Solid Explosives

7.18 Smoldering Transiting to Fire and Explosion: Flashover

7.19 Spontaneous Human Combustion

7.20 Thunderstorms and Lightning Strikes as Ignition Sources for Wild Fires

7.21 Ignition of Solid Fuels and Explosives having Low Melting Temperature

8 Ignition Sources for Detonation of Solid Explosives

8.1 Introduction

8.2 Detonation in Solid Explosives

8.2.1 Chapman-Jouguet, Overdriven, and Low-Velocity Detonation

8.3 Influence of Confinement on Initiation of Detonation

8.4 Initiation of Detonation by Strong Shock Waves.

8.4.1 Shock Mach Number Less than the CJ Detonation Mach Number (MS&lt

MCJ)

8.4.2 Shock Mach Number Greater than Mach Number of CJ Detonation (MS&gt

8.4.3 Low-Velocity Detonations

8.5 Detonator as an Ignition Energy Source

8.6 Initiation by Low-Velocity Impact

9 Ignition of Liquid Fuels and Liquid Explosives

9.1 Requirements for Ignition

9.2 Volatile Liquid Fuels

9.3 Ignition Sources for Volatile Liquid Fuels

9.3.1 Formation of Flammable Fuel Vapor-Air Mixture

9.3.2 Ignitability of Volatile Liquid Fuels

9.4 Ignition by Spark

9.4.1 Vaporization and Ignition by Heating

9.4.2 Wicks for Fuel Supply

9.4.3 Wicks for Premixed Fuel-Air Mixture

9.4.4 Vaporization of Droplets and Strong Spark

9.5 Ignition of Non-Volatile Liquid Fuels

9.5.1 Ignition by Hot Compressed Air in a Diesel Engine

9.5.2 Ignition in Ramjets and Scramjet

9.5.3 Ignition of Liquid Propellants in Rockets

9.5.4 Ignition and Popping in Liquid Propellant Rockets

9.5.5 Ignition Sources for Burners and Furnaces Using Heavy Fuel Oils

9.6 Fire and Explosion from Flowing Volatile Liquids by Electrostatic Charges

9.7 Explosion and Detonation of Liquid Explosives from Ingestion of Gas Bubbles

9.7.1 Detonation of Liquid Explosives from Gas Bubbles

9.8 Cavitation as an Ignition Energy Source

10 Ignition Sources for Gaseous Combustibles

10.1 Introduction

10.2 Energy Requirements

10.2.1 Auto-ignition

10.2.2 Influence of Ambient Temperature

10.3 Localized Nature of Ignition: Minimum Ignition Energy

10.3.1 Quenching Thickness

10.3.2 Minimum Ignition Energy

10.4 Initiation of Fire in a Stagnant Combustible Gas Mixture

10.4.1 Stretch and Heat Loss During Ignition of Stagnant Gas

10.4.2 Ignition and Stretch of a Flowing Combustible Gas.

10.5 Stretch and Quenching: Requirement of Pilot Flame

10.6 Pilot Ignition of High-Speed Combustible Gas Flow

10.7 Strength of Pilot Energy Source

10.8 Ignition by Hot Surfaces: Steady Flow Model of Yang

10.9 Role of Ignition Energy Sources on Rate of Pressure Rise

10.9.1 Unconfined Space

10.9.2 Confined Space

10.9.3 Hard or Strong Ignition and Weak Ignition Sources

10.9.4 Confinement with Obstructions

10.10 Energy Sources for Detonations: Overdriven, CJ and Low-Velocity Detonations

10.10.1 Energy Requirements

10.11 Example of Ignition Sources Causing Burning and Detonation

11 Unanticipated Thermal Ignition Sources

11.1 Thermal Threat and Insult

11.2 Confinement

11.2.1 Explosive Charges in Confinement

11.3 Fast Cook-off and Slow Cook-off Tests

11.3.1 Fixes for Fast Cook off

11.3.2 Fixes for Slow Cook off

11.4 Volatile Liquid Fuels in Confinement: BLEVE

11.5 Insensitive Explosive Systems

12 Shock Wave and Impact Threats for Confined Solid Explosives

12.1 Introduction

12.2 Nature's Way of Protection Against Adverse Environments

12.3 Shock Sources Causing Detonation: Sympathetic Detonation

12.4 High-Velocity Impact Energy Sources Causing Detonation, Explosion, and Fire

12.4.1 Solid Explosive in Confinement

12.4.2 Solid Explosive with Cavity or Bore

12.4.3 Bore Mitigation for Impact Threats

12.5 Barriers and Coatings

12.6 Relieving Detonation by Modifying Confinement

12.7 Modifying Explosive for Impact and Shock Energy Sources

A Temperature in a Shock Wave Propagating at Constant Velocity

B Acoustic Impedance and Confinement

B.1 Compressibility Coefficient

B.2 Acoustic Impedance and Shock Impedance

B.3 Reflection and Transmission of Pressure Disturbances at Interfaces.

C Ignition and Burning of Heavy Fuel Droplets Surrounded by Oxidizing Vapor.

Notes:

Includes index.

Description based on print version record.

Other Format:

Print version: Ramamurthi, K. Ignition Sources

ISBN:

9783031206870