(1) Crushed by impact. The material enters the crushing chamber by the impact of the high-speed plate hammer and the mutual impact between the materials, and there is also the friction between the plate hammer and the material, so that the material is broken along its fragile surface in the free state in the cavity. The dust generated by the impact crusher is also generated by the impact of the block group in space.

(2) Counterattack crushing. By the impact of the plate hammer on the rotor rotating at high speed, the material obtains a high movement speed, and then hits the impact plate, so that the material is further crushed. The flow of material bouncing back from the impact plate is determined by the impact plate curve.

(3) Milling and crushing. The material enters the plate sowing crushing area, and the large material is milled and crushed and thrown out by the plate that rotates at commercial speed one by one. In addition, the material that has not been crushed by the two crushing effects described in T is larger than the size of the discharge port, and is also cut and broken by the plate hammer iron that rotates at the commercial speed at the discharge port.

The above two crushing methods are dominated by free impact crusher.

There are many types of impact crushers, but they can be summarized into two types: single rotor and double rotor impact crusher.

The single-rotor reverse right-type crusher is divided into two types: single-rotor reversible rotation and irreversible rotation, and is divided into two types: with or without uniform plate. Double-rotor impact crusher, according to the different rotation directions of the rotor, there are three kinds of two rotors rotating in the same direction, opposite rotation and reverse rotation.

The double-rotor impact type with two rotors rotating in the same direction is equivalent to two single-rotor impact crushers used in series, which can complete coarse, medium and fine crushing operations at the same time, with a large crushing ratio, uniform product particle size, and a production capacity. This crusher reduces the number of crushing stages and simplifies the production process.

The impact crusher with two rotors rotating in reverse rotation is equivalent to two single-rotor impact crushers used in parallel, and the production capacity is separated from crushing larger pieces of materials and used as large-scale coarse and medium crushers.

The impact crusher with two rotors rotating in opposite directions mainly uses the materials thrown by the two rotors to hit each other for crushing, so the crushing ratio is large and the metal wear is less.
The main difference between hammer crusher and impact crusher: the plate and rotor of the impact crusher are rigidly connected, and the inertia of the entire rotor is used to impact the material, so that the material is not only crushed but also obtains greater speed and kinetic energy. Because the hammer head and the rotor are hinged, the hammer crusher only uses a single hammer to hit the material and crush the material, and the speed and kinetic energy obtained by the material are small.
The crushing cavity of the impact crusher is larger, so that the material has a certain space for movement, and makes full use of the impact effect, under the action of the plate hammer, the material impacts the impact plate. The crushing cavity of the hammer crusher is small, and the material is mainly crushed by the hammer.
The hammer of the impact crusher hits the material from the bottom up and throws it onto the impact plate, while the hammer head of the hammer crusher hits the material in the direction of the material.
The impact crusher generally does not have a grate, and the product particle size is controlled by the speed of the plate and the gap between the impact plate or the homogenizing plate. Under the hammer crusher (there is also a reversible crusher without grate), the crushed product is discharged through the sieve hole.