 # Category - Key equations for Process Engineers

## Heat transfer coefficients for heat exchangers

Steady state convective heat transfer on either side of a heat exchanger (hot or cold side) can be expressed with following figure and equation,

## Heat Transfer – Convection of Heat

Heat transfer by convection generally occurs between a fluid and a solid surface and convective heat transfer is accompanied by motion of the fluid. This is...

## Sample Problem – Gas liquid separator sizing with demsiter pad

Problem Statement
Perform separator sizing calculations for a vertical gas-liquid separator used for separation of fuel gas bubbles entrained in water...

## Sample Problem – Vertical Knock Out Drum Sizing Calculations

Sample Problem Statement
Design a vertical gas-liquid separator or a Knock Out Drum for separation of liquid droplets entrained in fuel gas flow. The liquid in...

## Air Compressibility Factor Calculation – Sample Problem

Problem Statement
Calculate the compressibility factor (Z factor) for air at the following temperature and pressure condition -
P = 15 barg
T =...

## Heat Transfer – Conduction of Heat

Conduction of heat in a solid wall is expressed using Fourier's equation for heat conduction,

T : Temperature at a point in wall
θ : Time
k : Thermal...

## Dynamic or Absolute viscosity and Kinematic viscosity

Fluid viscosity is an important fluid property in fluid dynamics. Fluid viscosity represents the frictional resistance within the fluid to shearing force...

## Flow Coefficient

Flow coefficient of a device represents the ease for a fluid flow to pass through the device. High flow coefficient of a device such as restriction orifice or...

## Bernoulli’s Equation

Incompressible Flow
For incompressible fluids, Bernoulli's equations simply states that the combined kinetic energy, gravitational static energy and pressure...

## Net Positive Suction Head definition – NPSH for pumps

NPSH definition
Net Positive Suction Head or NPSH for pumps can be defined as the difference between liquid pressure at pump suction and liquid vapor pressure...

## Compressibility factor

Definition
Compressibility factor of gases is a thermodynamic property which is used to modify the ideal gas equation for real gases.
For Ideal gases, Ideal...

## Work done in thermodynamic processes

A system can reach from state A to state B following different paths. These paths followed by a system while undergoing a change of state, are termed as...