Mill (grinding)

Mill (grinding)

A mill is a device that breaks solid materials into smaller pieces by grinding, crushing, or cutting. Such comminution is an important unit operation in many processes. There are many different types of mills and many types of materials processed in them. Historically mills were powered by hand (e.g., via a hand crank), working animal (e.g., horse mill), wind (windmill) or water (watermill).

Types of grinding mills

Windmill, wind powered

Windmills are mills that convert the energy of wind into rotational energy by means of vanes called sails or blades.

Watermill, water powered

Watermills are mills that use moving water as its power source.

Horse mill, animal powered

Horse mills are mills that use a horse as the power source.

Grain mill, for grain

Grain mills grind cereal grain into flour and middlings.

Sawmill, cuts timber

Sawmills cut timber into lumber.

Bark mill, produces tanbark for tanneries

Bark mills grind bark into a powder for use in tanneries.

Grinding laws

In spite of a great number of studies in the field of fracture schemes there is no formula known which connects the technical grinding work with grinding results. To calculate the needed grinding work against the grain size changing three semi-empirical models are used. These can be related to the Hukki relationship between particle size and the energy required to break the particles.

See also

• Millstone
• Gristmill, also called flour mill or corn mill
• Hammermill
• IsaMill
• Jet mill
• Mortar and pestle
• Pellet mill
• Planetary mill
• Stirred mill
• Three roll mill
• Vibratory mill
• VSI mill

This industrial process related article is a stub. You can help WikiMD by expanding it.