Guide
Material & Energy Balances
Checking Energy-Balance Units Before Using a Heat-Duty Result
A heat-duty number is only trustworthy if every factor in the energy balance uses compatible units. Check the mass basis of each flow,…
FROM THE AUTHOR
Luis J. Gillespie
Explore this author’s contributions to the ChemSOF engineering reference.
32 RESOURCES
Resources
Guide
Engineering Units
Absolute vs Gauge Pressure: Conversions and Common Input Errors
Absolute pressure is measured from a perfect vacuum, while gauge pressure is measured from the local atmospheric pressure, related by p(abs) = p(gauge)…
Guide
Engineering Units
Converting Pressure Difference to Fluid Head
To convert a pressure difference to fluid head, divide the pressure change by the fluid's weight density: h = ΔP/(ρg). For fresh water…
Guide
Engineering Units
How to Check Engineering Equations with Dimensional Analysis
Dimensional analysis checks that both sides of an engineering equation carry the same dimensions: a mismatch proves the equation is wrong, while a…
Guide
Material & Energy Balances
How to Organize Known and Unknown Variables Before Solving a Balance
Organizing knowns and unknowns before solving a balance means defining the system, choosing a basis, listing every known quantity with its units, assigning…
Guide
Engineering Units
Significant Figures and Rounding in Engineering Calculations
Significant figures are the digits in a number that carry meaningful information about its precision, and rounding trims calculated results so they do…
Guide
Engineering Units
Engineering Unit Conversions: A Practical Guide for Process Calculations
Unit conversion is the backbone of every chemical‑process calculation. This guide explains the fundamentals of engineering units, how to read and apply conversion…
Guide
Fluid Flow
Pumps and Piping: Hydraulic Power, Head, and System Curves
A pump offers hydraulic energy to a liquid along a pump curve, while the piping system demands energy along a system curve made…
Guide
Heat Transfer
LMTD Worked Example: Log Mean Temperature Difference for a Countercurrent Heat Exchanger
The LMTD of a countercurrent heat exchanger is the logarithmic average of the temperature differences at its two ends. For hot fluid cooling…
Guide
Engineering Computing
Process Simulation for Beginners: Choosing Models and Checking Results
Process simulation builds a mathematical model of a process and uses a computer to predict its behavior before the real system is run…