Rules of Thumb for Chemical Engineers


  • Carl R. Branan, Retired El Paso Natural Gas, El Paso, TX, USA

Rules of Thumb for Chemical Engineers, Fifth Edition, provides solutions, common sense techniques, shortcuts, and calculations to help chemical and process engineers deal with practical on-the-job problems. It discusses physical properties for proprietary materials, pharmaceutical and biopharmaceutical sector heuristics, and process design with simulation software, along with closed-loop heat transfer systems, heat exchangers, packed columns, and structured packings. Organized into 27 chapters, the book begins with an overview of formulae and data for sizing piping systems for incompressible and compressible flow. It then moves to a discussion of design recommendations for heat exchangers, practical equations for solving fractionation problems, along with design of reactive absorption processes. It also considers different types of pumps and presents narrative as well as tabular comparisons and application notes for various types of fans, blowers, and compressors. The book also walks the reader through the general rules of thumb for vessels, how cooling towers are sized based on parameters such as return temperature and supply temperature, and specifications of refrigeration systems. Other chapters focus on pneumatic conveying, blending and agitation, energy conservation, and process modeling. Online calculation tools, Excel workbooks, guidelines for hazardous materials and processes, and a searchable Rules of Thumb library are included. Chemical engineers faced with fluid flow problems will find this book extremely useful.
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Chemical Engineers


Book information

  • Published: June 2012
  • ISBN: 978-0-12-387785-7


"Branan's useful and convenient handbook for chemical and process engineers (at a bargain price) will be much appreciated by students and practitioners..."
American Reference Books Annual

Table of Contents

Publisher’s Note

1: Fluid Flow


    Data Required

    General Procedure

    Recommended Velocity

    Equivalent Length

    Shortcut Equation for Pressure Drop Due to Friction

    Reynolds Number

    Friction Factor

    Incompressible Flow

    Compressible Flow - Isothermal

    Compressible Flow - Transmission Equations


    Compressible Flow - Adiabatic

    Visual Basic Subroutines for Pressure Drop Due to Friction


    Control Valves

    Partially Full Horizontal Pipes

    Two-Phase Flow

2: Heat Exchangers



    Selection Guides

    Design Recommendations

    Process Data

    Heat Exchanger Configuration and Area

    Determining the LMTD Configuration Correction Factor

    Tubeside Pressure Drop

    Tube Side Film Coefficient

    Shell Diameter

    Ideal Shell Side Film Coefficient

    Shell Side Film Coefficient Correction Factors

    Overall Heat Transfer Coefficient

    Shell Side Pressure Drop

    Heat Transfer Coefficients

    Fouling Resistances

    Installation Recommendations

    Thermal Conductivity of Metals

    Vacuum Condensers

    Air-cooled Heat Exchangers: Forced vs. Induced Draft

    Air-cooled Heat Exchangers: Air Data

    Air-cooled Heat Exchangers: Thermal Design

    Air-cooled Heat Exchangers: Pressure Drop, Air Side

    Air-cooled Heat Exchangers: Temperature Control

3: Fractionators


    Separation Factor

    Relative Volatility

    Vapor-Liquid Equilibrium

    Activity Coefficients

    Establishing the Column Pressure

    Minimum Reflux - Binary

    Minimum Reflux - Multicomponent

    Minimum Stages

    Relationship of Theoretical Stages to Reflux Ratio

    Feed Location

    Reflux-to-Feed Ratio

    Actual Trays

    Graphical Methods - The McCabe-Thiele Diagram

    Plotting With Murphree Tray Efficiency

    Tray Efficiency Rules of Thumb

    Using the McCabe-Thiele Plot

    Column Internals - Trays and Packing

    Column Tray Spacing

    Tower Diameter - Souders-Brown Correlation

    Pressure Drop - Trays

    Control Schemes


    Packed Columns

4: Absorbers


    Hydrocarbon Absorber Design

    Inorganic Absorbers

    Packing Height for Mass Transfer in Packed Columns

    Overall Mass Transfer Coefficient

5: Pumps


    Pump Types and Selection

    Pump Testing

    System Curves

    Operating Point and Pump Selection

    Flow Control with Throttling Valve

    Charting Control Characteristics

    Flow Control by Changing the Pump Speed

    Affinity Laws


    Minimum Flow

    Temperature Rise

    Suction System NPSH Available

    Suction System NPSH for Studies

    Multiple Centrifugal Pumps in Parallel or in Series

6: Fans, Blowers and, Compressors


    Rules of Thumb


    Fan Noise

    Blower Types

    Compressor Types

    Surge Control

    Performance Calculations

    Affinity Laws

    Power - Fan

    Power - Reciprocating Compressor

    Power - Centrifugal Compressor

    Comparison with Manufacturer’s Data

    Power with P-E Diagram

    Cost of Compressed Air

    Receiver Volume

    Time to Pump System to Pressure

7: Drivers


    Electric Motors

    Motor Voltages

    Motors: Efficiency

    Motors: Starter Sizes

    Motors: Useful Equations

    Motors: Overloading

    Air-Driven Motors

    Hydraulic Motors

    Steam Turbines: Steam Rate

    Steam Turbines: Efficiency

    Gas Turbines: Performance

    Internal Combustion Engines: Fuel Rates

    Gas Expanders: Available Energy

8: Vessels


    General Rules of Thumb for Vessels

    Tank Dimensions

    Liquid Volume at Any Fill Height

    Time to Drain a Tank

    Emissions from Storage Tanks

    Load Cells

    Liquid-Liquid Separators

    Vapor-Liquid Separators

    Liquid Surge Volume

    Vapor Velocity in the Disengagement Section

    Vapor-Liquid Separator Size

    Vessel Specifications

    Good Engineering Practices for Storage Tank and Vent Relief Design

9: Boilers


    Boiler Horsepower

    Types of Packaged Boilers

    Power Plants


    Thermal Efficiency

    Stack Gas Enthalpy

    Steam Drum Stability

    Deaerator Venting

    Water Alkalinity

    Source Water Impurities

    Conductivity versus Dissolved Solids

    Silica in Steam

    Caustic Embrittlement

    Waste Heat

    Boiler Feedwater

    Blowdown Control

    Best Practices - Burner System Piping

10: Cooling Towers


    Mechanical Draft Cooling Towers

    Material and Energy Balance Calculations

    Rating Nomenclature

    Performance Calculations

    Operations and Accessories

    Water Quality Guidelines

    Scale Prevention

11: Refrigeration



    Indirect and Direct System Design

    Horsepower per Ton


    Refrigerant Containment

    Steam Jet Ejectors

    Ammonia Absorption Utilities Requirements

12: Closed Loop Heat Transfer Systems


    Selecting the Heat Transfer Fluid

    Types of Heat Transfer Fluids

    Heat Transfer Coefficient

    System Design

    Temperature Control

    Physical Properties of Commercial Heat Transfer Fluids

13: Biopharmaceutical Systems


    Contamination Root Causes

    Contamination Investigation and Recovery

    Microbiology Investigation

    Risk Assessment


14: Vacuum Systems


    Vacuum Units

    Conversion between Mass Flow, Actual Volume Flow, and Standard Volume Flow

    Comparison of Vacuum Equipment

    Vacuum Jets

    Liquid Ring Vacuum Pumps

    Dry Vacuum Pumps

    Typical Jet Systems

    Steam Supply

    Measuring Air Leakage

    Time to Evacuate

    Instrumentation and Controls

15: Pneumatic Conveying


    Flow Regimes

    Types of Systems

    System Design Procedure

    Saltation Velocity

    Pressure Drop

    Prime Movers

    Feed Systems

    Conveyor Piping


16: Blending and Agitation



    Impeller Types

    Dimensional Analysis


    Solids Suspension

    Gas Dispersion

    In-Line Mixers

    High Shear Mixers

    Mixing Solids

    Mechanical Design

    Impeller Weight

17: Process Evaluation


    Accuracy of Cost Estimates

    User Requirements

    Block Diagrams

    Process Flow Diagrams (PFDs)

    Basis of Design

    Block-Sequential Diagrams

    Piping & Instrumentation Diagrams (P&IDs)

    Data Sheets and Specifications

    Capital Cost Estimates

    Organization of a Cost Estimate


18: Reliability


    Initial Design

    Risk Analysis

    Sustainable Practices

19: Metallurgy


    Cost Comparison

    Embodied Energy


    Stress-Corrosion Cracking

    Hydrogen Attack

    Pitting Corrosion

    Creep and Creep-Rupture Life

    Naphthenic Acid Corrosion

    Thermal Fatigue

    Abrasive Wear

    Pipeline Toughness

    Common Corrosion Mistakes

20: Safety


    Process Safety Management (PSM)

    Process Hazard Analysis (PHA)

    Safe Design Practices

    Emergency Vent Systems

    Flash Point of Binary Mixtures

    Deflagration Prevention or Control

    Prevent Backflow

    Equipment Purging

    Electrical Area Classification

    Causes for Loss of Containment

    Dust Explosion Hazards

21: Controls


    Basic Nomenclature

    Definitions of Control Modes

    Cascade Control

    Specifying Instruments to Measure Values

    Control Ranges

    Drawing Conventions

    Artistic Expression

    Safety Instrumented Systems

    Enclosures: NEMA and IP

22: Troubleshooting


    General Troubleshooting Approach

    Diagnostic Tools


    Control Valves (Process Control)

    Shell-and-Tube Heat Exchangers

    Plate-and-Frame Heat Exchangers

    Fractionation Towers

    Fractionation Case Histories

    Centrifugal Pumps


    Steam Jet Vacuum Systems


23: Startup


    Startup Management

    Change Control During Startup

    Startup Cost

    Systems Approach

    Construction Quality

    Startup Checklists

    Operating Modes

24: Energy Conservation


    Calculating Steam Cost

    Steam System Rules of Thumb

    Equivalent Cost of Fuels

    Steam Traps

    Energy Efficient Design for Fractionators

    Pinch Analysis


25: Process Modeling


    Concepts and Terminology

    Equipment Design

    Mass and Energy Transfer

    Flowsheet Simulation - Continuous Process

    Flowsheet Simulation - Dynamic Process

    Discrete Process Simulation

    General Purpose Simulation Environments

    Software List

26: Conversion Factors and Constants

    Significant Figures and Rounding

    Gas Constant

    Standard Gas Volume

    Atmospheric Pressure

    Irrigation Conversion

27: Properties


    Approximate Physical Properties

    Vapor Pressure Equation

    Liquid Viscosity

    Relative Humidity

    Surface Tension

    Thermodynamic Properties of Water and Steam

    Gas Diffusion Coefficients

    Bulk Modulus

    Water and Hydrocarbons

    Compressibility Factor

    Inorganic Gases in Petroleum

    Foam Density

    Equivalent Diameter

    Properties Data Sheet

Appendix A: Resources

Appendix B: Tank Cleaning