Hammer crusher
The hammer crusher belongs to the machine family of crushers and is used to crush material such as limestone lumps . The single-shaft or double-shaft hammer crusher is one of the most widely used types of crushers. The crushed material is crushed by impact and impact crushing . Machines based on the same principle, which grind the material more finely, are called hammer mills .
history
The principle of breaking rock with hammer-like weights was already used in the Middle Ages. In his book De re metallica from 1556 , Georgius Agricola describes a hammer crusher that was powered by a water mill and used to crush ore . In the centuries that followed, the technology used remained largely unchanged.
In the 19th century, advances in metallurgy allowed hammer crushers to be made from steel . At the same time, it was now powered by a steam engine . The hammer crushers produced in this way were more powerful and could also be set up away from watercourses. This made the hammer crusher interesting for use in road construction . The laborious crushing by hand became superfluous, as steam-powered hammer crushers from then on supplied the aggregate required for the construction of macadam roads.
At the turn of the century, new crushing machines, such as jaw and gyro crushers , came onto the market and competed with the hammer crusher .
technology
Hammer crushers consist of a rotor with discs on which hammers are attached in an articulated manner in the outer area. They are structurally similar to horizontal impact crushers . The high centrifugal mass of the rotor enables single-stage shredding of feed pieces with edges up to 2.5 m in one work step to less than 25 mm. Throughput rates of over 2,000 t / h are achieved.
Hammer crushers are simple and compact in construction, robust in construction, powerful, safe and low-maintenance in operation. They are particularly suitable for the crushing of medium-hard, also moist rock, and they also have a good crushing ratio (1:10 to 1:15). They are only used stationary or semi-mobile.
literature
- Günter Kunze: Construction machinery . Vieweg + Teubner Verlag, Wiesbaden 2002, ISBN 3-528-06628-8 , pp. 360 .
Individual evidence
- ^ Francis Pierre: The fascination of construction machinery - road construction history . Giesel Verlag, 1998, ISBN 3-9802942-8-5 .