Jaw crusher
Jaw crushers (also jaw crushers ) are used for the rapid coarse and pre-crushing of brittle , medium-hard and hard materials . Its name is derived from the crushing jaws necessary for the crushing .
Working principle
The feed material enters the crushing chamber through a funnel . The crushing then takes place in the wedge-shaped shaft between the fixed and the crusher jaw moved by an eccentric shaft. Due to the elliptical sequence of movements, the feed material is crushed and transported downwards. As soon as the material is finer than the set minimum distance between the crushing jaws, it falls into a collecting container. The single-toggle jaw crushers and double toggle-lever jaw crushers that dominate the market are known as further designs.
Executions
Jaw crushers are available both as tabletop and stand-alone units. In addition, they can be integrated into the production series as online devices. They therefore differ greatly in size and also in their areas of application. Table-top devices can usually shred materials with an initial grain size of a few centimeters, while larger floor-standing devices can crush larger materials with an initial grain size of up to 15 cm. In addition, the devices differ in the setting of the gap width between the crushing jaws. Depending on the hardness of the material to be crushed, manganese steel , stainless steel , zirconium dioxide or tungsten carbide are used for the crushing jaws . Most floor-standing devices can be set using a scale, table-top devices can also have a digital display that shows the gap width. There are also jaw crusher buckets for use with excavators.
Zero point adjustment
Depending on the load and the material of the jaws, wear and tear can be expected sooner or later. This means that the set distance between the crushing jaws increases over time. In order to continue to get reliable and uniform results, it is necessary to adjust the zero point (i.e. the point at which the two jaws meet). However, this is only possible with continuously adjustable jaw crushers. To do this, while the device is running, the gap width setting is shifted until the crushing jaws audibly touch. This is then the new zero point. To fix the new point, either the scale is shifted accordingly or the reset button is pressed on a digital display.
Use in industry
On an industrial scale, jaw crushers are used in the processing of mineral raw materials , such as B. iron ore , mainly used in quarries or for crushing soil and rock samples as a primary crusher stage. With an inlet opening of up to 2 m, the rock is broken up to an edge length of approx. 0–450 mm. This comminution can be seen as the first stage in the preparation of raw materials in mining . The material obtained in this way is often further crushed in mobile or stationary cone crushers or in stationary ball mills of various designs.