Comminution

Grinding is one of the four major classes of process mechanical process engineering and describes the displacement of the particle size distribution (particles, droplets, gas bubbles) in a finer size range. The others are agglomeration, mixing and separating.

The grinding must each from everyday life are known, he has already done in the kitchen. Man cuts, grates, crush, or grind as food and spices in order to prepare their palatability to develop their taste or odor, or simply to bring them into a more pleasing shape.

Industrial applications are for example in the mineral processing ( extraction of raw materials ), waste recycling, food production and the ceramic industry.

Solids

The process of grinding can be distinguished on the basis of the substance group:

The concept is aimed mostly from crushing on solids. Depending on the grain size and hardness of the grain type distinction is coarse crushing, fine crushing and rough grinding with particle sizes of the starting material of 50 mm to 0.5 mm and fine grinding, fine grinding and grinding colloid with particle sizes of 500 microns to less than 5 microns. The naming of the results of the crushing ranges from boulders on gravel, Split, meal, flour, powder, down to colloidal fineness. For use shredders come as jaw crusher, impact crusher, hammer mills, ball mills, colloid mills, high-pressure grinding roll mills, single shaft shredders and many others.

See also: degree of division

Liquids

When liquids are " broken ", it is called Flüssigkeitszerteilung and in detail of irrigation, atomization (eg hairspray ) and Zerspritzung. When sprinkling the liquid is distributed in rays or large droplets during atomisation - often through nozzles - in fine to very fine droplets. When splatter the liquid is broken by rotating machine parts or baffles. Examples of Flüssigkeitszerteilung are cooling, absorption, gas purification, drying by atomization, fuel atomization in combustion and selective reactions between gases and liquids. The atomization of liquids, emulsions or suspensions occupies a special position in the coating of surfaces ( painting).

Gases

If gases are crushed, ie gas bubbles in a liquid environment, one speaks of gassing (whirlpool, bioreactor ).