Edge mill

The pug mill is a grinder for grinding and mixing of stone, ores and food. One to two upright heavy glasses, called runners, turn on a base plate about a vertical axis and so crushed the content.

Description

The force acting on the material to be ground, is not only the weight of the rotor, but it creates an additional force by their Präzessionstendenz.

If the runners are on the bottom plate roll clean, they must be cones whose tips meet in the vertical axis. Indeed, the tops of the cones are directed outwardly so that a relative movement between the rotor and the base plate is formed. The material is not only crushed, but also torn.

The base plate is ( at least for the food pan mills ) also made of stone. The material is placed in the empty pan mill, ground and then removed with stationary stones. Due to this approach the discontinuous edge runner was replaced by the continuous rolling chair over time. In some processes, but the pug mill permits a continuous process and is therefore still state of the art, such as pellet mills

• In the production of chocolate in the pan mill squeezed the cocoa beans into cocoa mass.

• In the old mills of the pug mill squeezed nuts to win vegetable oils for oil lamps and food. In the oil mills consist runners and base plate made of monolithic granite.

• In historic paper mills, the fibers were achieved with a pug mill. Even in industrial era pug mills were first used in paper production for pulping of waste paper or wood pulp or cellulose plates. Today we used here usually a pulper.

The pug mill is to be found in modern production hardly as big, expensive stones are needed. The pug mill is also the tendency that part of the ground material is thrown. Therefore, today rolling chairs are usually used.

In the ceramics are found today even pug mills, especially for structural ceramics. When brick production Koller rolls are used with 25 tons of weight. In the cement production are found for grinding the raw material ( limestone) roller mills, which represent a kinematic inversion of the edge runner: the disk, called the grinding table, turns up on a gear under the grinding rollers which have partly a weight up to 80 tons ( as a pair of rollers having inner and outer roller ) and additionally pressed hydraulically with another 200 tons. This pug mill reversals are operated continuously: the raw material is continuously fed into the Mahltellermitte; sufficiently finely ground material ( raw meal for the furnace process ) is highly promoted by airflow means " air classifier ".