Entrainment (engineering)

This article is about Entrainment (engineering). For other uses of the term Entrainment, please see Entrainment (disambiguation).

Entrainment as commonly used in various branches of science and engineering may be defined as the entrapment of one substance by another substance.

Types of entrainment

There are a great many types of entrainment encountered in chemistry, chemical engineering, other engineering disciplines and in atmospheric sciences. Here are a number of examples:

• The entrapment of liquid droplets in air or any other gas as in aerosols or fog or spray painting.
• The entrapment of liquid droplets and solid particulate matter in a flowing gas, as in smoke entrapped in combustion flue gases.
• The entrapment of gas bubbles or solid particulates in a flowing liquid, as with aeration.
• Given two mutually insoluble liquids, the emulsion of droplets of one liquid entrapped in the other liquid, as with margarine.
• Given two gases, the entrapment of one gas into the other gas.
• The intentional entrapment of air bubbles in concrete.
• The entrapment of solid particles in an air or other gas as in fluid catalytic cracking, fluidized combustion and many other processes utilizing fluidized solids.