Impact crusher
Impact crushers are machines for crushing material and a special type of crusher .
They shred the material to be crushed using impact crushing by generating high kinetic energy with which the crushed material hits a sharp-edged and harder object. The impact of the chunks of material on the strips creates stress peaks in the material that spread at different speeds and thus lead to selective shredding. Areas of the material with lower strength are opened up particularly well, harder particles are therefore released from a softer environment.
This kinetic energy can be built up in two ways, mostly both types are used in the crusher. Firstly, by strongly accelerating the material to be broken and hurling it onto a fixed impact mechanism. Second, the material to be crushed is fed at a moderate speed onto a rapidly rotating drum with baffle edges.
In the case of a rotating impact mechanism, when the material hits the impact strips, the material is accelerated and thrown back onto the lining of the impact space or onto the impact mechanisms protruding into the impact space. In the course of the material flow, there are multiple impact processes and collisions with other material. The degree of size reduction is usually higher than that of jaw and rotary crushers .
Types
Horizontal impact crusher
The axis alignment of the rotor is horizontal. The material is fed in at an angle from above by means of an inlet chute, sometimes also from above in the middle. Several axially arranged blow bars (usually 3 to 6 pieces) are attached to the rotor circumference. The peripheral speed can be between 18 and 70 m / s. The higher the speed, the higher the degree of comminution. The blow bars capture the feed material, which accelerates it very quickly. Then the material hits one or more baffles that are attached to the inside of the housing. This is where the main shredding takes place. The circumferential speed of the rotor and the gap setting between the blow bars and the impact walls influence the grading curve of the end product. The horizontal impact crusher can be used both in the first and in a subsequent crushing stage. As a rule, it achieves a relatively high degree of shredding. It is mainly used to crush hard, brittle and moderately abrasive rock.
Vertical impact crusher
In a vertical impact crusher, the rotor axis is oriented vertically. The material is fed into the center of the rotor from above. The material is thrown outwards at high speed by centrifugal forces , where it encounters wear elements arranged in a ring. Impact crushing takes place there. The end product then falls down into one or more shafts. The shredding result can be influenced by the rotor speed. With the vertical impact crusher, each individual grain of the feed material is subjected to targeted and uniform loading. This is why the machine is not only suitable for crushing, but also for sand production, and especially for improving the grain shape of the end product.
Individual evidence
- ↑ Impact crusher and impact mill (Homepage BHS-Sonthofen). Retrieved February 26, 2016 .
- ↑ Rotor centrifugal crusher (Homepage BHS-Sonthofen). Retrieved February 26, 2016 .