http://greaves.co.uk/

Mixing involves manipulating a heterogenousphysical system (i.e. a non-uniform substance, with different components) and making it more homogenous and uniform.

For example, pouring water into a swimming pool to homogenise the temperature.

Mixing is performed to allow heat/mass transfer to occur between different components.

There are different types of mixing classification

SINGLE PHASE BLENDING MULTI-PHASE MIXING

This refers to liquids that mix, and dissolve easily into one another

Momentum of one or more liquid is high enough to cause enough turbulence to mix the two. Blending in a more viscous liquid (e.g. honey) requires greater mixing power

Liquids that are not easily soluable often require different equipment

Specialized mixers for this purpose, called high shear devices, or HSDs, rotate at high speeds and generate intense shear which breaks up liquid into droplets.

There are two types of liquid-solid mixing.

Suspension – the suspension of coarse, free flowing solids, which is done to improve the rate of mass transfer between liquids and solids.

Deagglomeration – fine powders may agglomerate (form solid lumps) during storage. The agglomerate particles must be subjected to intense shear to break them up.

An example of this type of mixing is the production of milkshakes from liquid mild and solid ice cream

Liquids and gases are mixed to allow mass transfer to occur.

For example, in the case of air stripping, gas is used to strip volatiles from a liquid.

Finally, gas solid mixing is used to transport small, particulate solids from one place to another, or to mix gaseous reactants with solid catalysts.