Chemistry and Metallurgy

Contents

List of Illustrations

Chapter 1. Fuel and Oil

1.1. Introduction to Power Station Chemistry

1.1.1. Historical

1.1.2. The Work of the Power Station Chemist

1.2. Coal

1.2.1. Introduction

1.2.2. British Coal Resources

1.2.3. British Coal Production and Utilization in C.E.G.B. Power Stations

1.3. Classification of Coal

1.3.1. Dr. Seyler's Classification

1.3.2. Dr. Seyler's Fuel Charts

1.3.3. The N.C.B. Coal Rank Code Number Classification

1.3.4. Coal Rank Code Numbers in Power Station Practice

1.4. Classification of Coal by Size

1.5. Preparation of Coal

1.5.1. Introduction

1.5.2. Coal Preparation for Power Station Use

1.5.3. Coal Cleaning

1.5.4. Wet Processes

1.5.5. Dry Cleaning

1.5.6. Partial Preparation of Coal for Modern Power Station Use

1.6. Coal—the Price Structures

1.6.1. Industrial Coal Price Structure

1.6.2. Carbonization Coal Price Structure

1.6.3. The Slurry Price Schedule

1.7. Transport of Coal to Power Stations

1.7.1. Rail

1.7.2. Coastwise Shipment

1.7.3. Road

1.7.4. Other Methods

1.8. Coal Storage

1.9. Coal Sampling

1.9.1. Purpose of Sampling

1.9.2. Theory of Sampling

1.9.3. Replicate Sampling

1.9.4. Sampling Processes

1.9.5. Sampling for Moisture

1.9.6. Storage of Samples

1.10. Sample Preparation

1.10.1. Introduction

1.10.2. Errors of Sample Preparation

1.10.3. Equipment for Sample Preparation

1.11. Analysis and Testing of Coal and Coke

1.11.1. Introduction

1.11.2. Proximate Analysis

1.11.3. Moisture Content

1.11.4. Ash

1.11.5. Volatile Matter

1.11.6. Calorific Value

1.11.7. Sulfur

1.11.8. Chlorine

1.11.9. The Ultimate Analysis of Coal

1.11.10. Phosphorus

1.11.11. Arsenic

1.11.12. Swelling Index

1.11.13. Gray-King Coking Test

1.11.14. Carbon Present as Carbonates

1.11.15. Reporting of Results

1.11.16. Instrumental Analysis

1.12. Other Tests on Coal

1.12.1. Bulk Density

1.12.2. Grindability

1.12.3. Handleability

1.13. Size Analysis

1.13.1. Size Analysis of Coal

1.13.2. Sampling and Size Analysis of Pulverised Fuel

1.14. Ash from Coal

1.14.1. Boiler Fouling

1.14.2. Analysis of Gas-side Deposits

1.14.3. Analysis of Ash

1.14.4. Ash Fusion Temperature

1.15. Gas-side Cleaning of Boilers

1.15.1. On-load Cleaning

1.15.2. Off-load Cleaning

1.16. Commercial Utilization of Ash

1.16.1. Characteristics of P.F.A.

1.16.2. Commercial Utilization of P.F.A.

1.17. Oil Fuels

1.17.1. Introduction

1.17.2. World Oil Supplies

1.17.3. Crude Oil Refining

1.17.4. Refining in the U.K.

1.17.5. Utilization of Petroleum in the U.K.

1.18. British Standard Classification of Oil Fuels

1.18.1. Introduction

1.18.2. Engine Fuels

1.18.3. Burner Fuels

1.19. Burner Fuels

1.19.1. Typical Characteristics

1.20. Use of Oil Fuel by the C.E.G.B.

1.20.1. Lighting-up Uses

1.20.2. Boilers converted to Burn Heavy Fuel Oil

1.20.3. Other Fuel Oil Conversions

1.20.4. Fuel for Gas Turbines

1.20.5. Future use of Oil Fuel by the C.E.G.B.

1.21. Oil Firing—Delivery and Sampling

1.21.1. Delivery

1.21.2. Measurement

1.21.3. Sampling

1.21.4. Sampling from Pipelines

1.21.5. Sampling from Ships

1.21.6. Sampling from Road and Rail Tank Cars

1.21.7. Sampling from Storage Tanks

1.21.8. Sample Containers

1.22. Testing

1.22.1. Safety Precautions

1.22.2. Specific Gravity

1.22.3. Viscosity

1.22.4. Cloud and Pour Point

1.22.5. Calorific Value

1.22.6. Sulfur

1.22.7. Sodium

1.22.8. Vanadium

1.22.9. Ash Content

1.22.10. Sediment

1.23. Storage and Handling

1.23.1. Policy

1.23.2. Practice

1.24. Oil Firing—Combustion and Associated Problems

1.24.1. Combustion

1.24.2. High-temperature Fouling and Corrosion

1.24.3. Low-temperature Fouling and Corrosion

1.24.4. Factors Affecting the Acid Dew Point

1.24.5. Control of Low-temperature Corrosion

1.24.6. Smut Emission

1.24.7. Gas-side Cleaning of Oil-fired Boilers

1.24.8. Ash Disposal from Oil-fired Boilers

1.25. Testing of Fuel Oils

1.25.1. Viscosity

1.25.2. Specific Gravity

1.25.3. FlashPoint

1.25.4. Water Content

1.25.5. Sediment

1.25.6. Ash—Sodium and Vanadium

1.25.7. Cloud and Pour Points

1.25.8. Gross C.V. and Ultimate Analysis

1.25.9. Sulfur

1.26. Testing of Flue Gases

1.26.1. Introduction

1.26.2. Dew point Measurement and Rate of Acid Build-up

1.26.3. Corrosion Probe Tests

1.26.4. Acid Deposition Rate

1.26.5. High-temperature Deposition Measurement

1.26.6. Dust Burden Measurement

1.26.7. Gas Analysis—Carbon Dioxide and Oxygen

1.27. Air Pollution

1.27.1. Introduction

1.27.2. The Nature of the Pollutants

1.27.3. Measurement of Pollution

1.27.4. Results

1.28. Lubricating Oils

1.28.1. Turbine Oil

1.28.2. Other Lubricating Oils

1.28.3. Additives and Inhibitors

1.28.4. Sampling

1.28.5. Tests and Their Significance

1.28.6. Purification of Lubricating Oil

1.28.7. Operating Troubles in Turbine Oil Systems

1.28.8. Fire-resistant Oils

1.29. Greases

1.29.1. Introduction

1.29.2. Lime-base Greases

1.29.3. Soda-base Greases

1.29.4. Aluminum-base Greases

1.29.5. Lithium Greases

1.29.6. Complex Greases

1.29.7. Fluid Greases

1.29.8. Block Greases

1.29.9. New Greases

1.29.10. Graphite and Molybdenum Disulfide Greases

1.29.11. Greases for Nuclear Applications

1.29.12. Problems

1.29.13. Properties of Greases

1.29.14. Consistency

1.29.15. Drop Point

1.29.16. Resistance to Shear

1.29.17. Resistance to Oxidation

1.29.18. Resistance to Water

1.30. Insulating Oil

1.30.1. Introduction

1.30.2. Characteristics

1.30.3. Sampling

1.30.4. Testing

1.30.5. Purification

1.30.6. Fire-resistant Synthetic Insulating Oils

1.31. Buchholz Gas Analysis

1.31.1. Introduction

1.31.2. Analysis

1.31.3. Chemical Reactions

1.31.4. Test Apparatus

Exercises

Chapter 2. Corrosion. Feed and Boiler Water

2.1. Introduction

2.1.1. Chemistry of Reactions in Solution

2.2. The Corrosion of Metals

2.2.1. Introduction

2.2.2. An Electrochemical Cell

2.2.3. A Simple Corrosion Cell

2.2.4. Electromotive Force and Polarity of Bimetallic Couples

2.2.5. Galvanic Corrosion

2.2.6. The Effect of Polarization on Currents Flowing in Corrosion Cells

2.2.7. The Corrosion of Single Metals

2.2.8. Differential Aeration

2.2.9. A Review of Factors Affecting Corrosion Rates

2.3. Feed and Boiler Water

2.3.1. Introduction

2.3.2. Historical Survey

2.3.3. Boiler Water

2.3.4 Feed Water

2.3.5. Once-through Boiler Plant

2.4. On-load Corrosion of Boilers

2.4.1. Occurrence

2.4.2. Protective Magnetite and the Effect of Caustic Soda

2.4.3. Effect of Heat Transfer and Related Phenomena

2.4.4. Non-protective Magnetite

2.4.5. Corrosion Processes in the Boiler

2.4.6. Prevention of On-load Corrosion

2.5. Generation Operation Memoranda Nos. 67 and 72

2.5.1. Introduction

2.5.2. Generation Operation Memorandum No. 67

2.5.3. Generation Operation Memorandum No. 72

2.6. Sampling and Analysis of Feed Water, Boiler Water and Steam

2.6.1. Introduction

2.6.2. Sampling and Analysis

2.6.3. Boiler Water Sampling

2.6.4. Steam Sampling

2.6.5. Feed Water Sampling

2.7. Instrumentation for Water Quality Control

2.7.1. Introduction

2.7.2. Measurement of Electrical Conductivity

2.7.3. Measurement of pH Value

2.7.4. Measurement of Dissolved Oxygen

Suggestions for Further Reading

Exercises

Chapter 3. Water Treatment Plant: Cooling Water Systems

3.1. Introduction

3.2. Sources and Quality of Raw Water

3.2.1. Chemical Composition

3.3. Boiler Feed Water Make-up

3.3.1. Town Supply Water Treatment

3.3.2. River Water Treatment

3.4. Water Softening

3.4.1. Lime/Soda Softening

3.4.2. Types of Lime and Lime/Soda Softeners

3.4.3. Calculation of Softening Charges and Control of Water Softening

3.4.4. Base-exchange or Zeolite Softening

3.4.5. Lime/base-exchange Softener

3.4.6. Blend Softener

3.4.7. Weakly Acidic Cation Exchange/base-exchange Softener

3.4.8. Other Softening Processes

3.5. Evaporators

3.5.1. Scale Prevention

3.5.2. Evaporator Blowdown

3.5.3. Evaporator Cleaning

3.5.4. Evaporator Distillate Quality

3.6. Déminéralisation

3.6.1. Synthetic Ion-exchange Resins

3.6.2. Regeneration

3.6.3. Déminéralisation Processes

3.6.4. Practical Considerations

3.6.5. Recent Developments

3.7. Choice of Make-up Water Treatment Plant

3.8. Cooling Water Systems

3.8.1. Scale Deposition on Heat Exchange Surfaces

3.8.2. Control of Organic Growth

3.8.3. Maintaining Condenser Cleanliness

3.8.4. Control of Marine Growth

3.8.5. Corrosion in Cooling Water Systems

3.8.6. Dry Cooling Towers

3.8.7. Protection of Cooling Tower Timber

References

Exercises

Chapter 4. Plant Cleaning and Inspection

4.1. Introduction

4.2. Pre-Commissioning Cleaning of Steam/Water Circuits

4.2.1. Reasons for Pre-commissioning Cleaning

4.2.2. Development of Cleaning Processes

4.2.3. Chemistry of the Cleaning Processes

4.2.4. Administration and Planning

4.2.5. Criteria of Satisfactory Results

4.2.6. Inspection before Cleaning

4.2.7. Alkali Boil-out

4.2.8. Acid Cleaning

4.2.9. Draining Acid and Flushing

4.2.10. Passivation

4.2.11. Final Inspection

4.2.12. Control of the Cleaning Process

4.2.13. Disposal of Effluents

4.2.14. Purging of Superheater and Reheater

4.2.15. Safety

4.2.16. Works Cleaning and Protection of Plant

4.2.17. Site Erection under Clean Conditions

4.3. Pre-commissioning Preparation of Turbine Oil Systems

4.3.1. Introduction

4.3.2. Purposes

4.3.3. Works Cleaning and Protection

4.3.4. Flushing

4.4. Plant Cleaning during Service Life

4.4.1. Boilers and Economizers

4.4.2. Turbine Oil Systems

4.4.3. Feed Heaters

4.4.4. Condensers

4.4.5. Evaporators

4.4.6. Turbine Blading

4.5. Inspection of Plant

4.5.1. Introduction

4.5.2. Inspection at Planned Outage or Overhaul

4.5.3. Inspection Techniques

4.6. Recent Developments

4.6.1. Protection of Austenitic Parts

4.6.2. Boiler Plant Purging with Nitrogen

4.6.3. Safety

4.6.4. Sub-surface Cavitation

4.6.5. Passivation

Appendix. Record of the Cleaning of the Boiler System of a 350 MW Unit

References

Exercises

Chapter 5. Metallurgy and Welding

5.1. Introduction

5.2. Ferrous Metallurgy

5.2.1. Production of Iron and Steel

5.2.2. Solidification Processes

5.2.3. Crystallographic Structure and the Allotropy of Iron

5.2.4. Constitution of Steel

5.2.5. Heat Treatment of Steel

5.2.6. Cast Irons

5.2.7. Deformation and Fracture

5.3. Criteria for the Assessment of Materials

5.3.1. Mechanical Properties at Ambient Temperature

5.3.2. Physical Properties

5.3.3. Temperature-dependent Mechanical Properties

5.3.4. Weldability

5.3.5. Corrosion Resistance

5.4. Fabrication

5.4.1. Material Production and Forming

5.4.2. Welding

5.4.3. Weldability and Defects in Welds

5.4.4. Desirable Weldment Properties

5.4.5. Welding Applications in Construction of C.E.G.B. Plant

5.5. Non-destructive Examination

5.5.1. Visual Methods

5 5.2. Magnetic Crack Detection

5.5.3. Penetrant Inspection

5.5.4. Radiography

5.5.5. Ultrasonic Flaw Detection

5.5.6. Electrical/Magnetic Methods

5.6. Metallurgical Aspects of Power Plant Failure

5.6.1. Boiler Plant

5.6.2. Steam Pipework and Valves

5.6.3. Turbo-generator Plant

5.7. Concluding Remarks

Glossary of Welding Terms

References

Recommended Reading

Exercises

Contents of Volumes 1-8