How does an impact crusher work?

Impact Crusher is a high-efficiency crushing equipment widely used in mining, building materials, chemical industry, metallurgy and other industries. It is mainly used for crushing medium-hard and brittle materials. Its working principle is based on the collision, friction and shearing of materials with the impact plate under the impact of the high-speed rotating rotor hammer to achieve crushing. The following is a detailed analysis of its working process:

1、Working principle of impact crusher
Core principle: Use “kinetic impact + impact collision” to achieve material crushing.
Key components: rotor, hammer, impact plate, feed port, discharge port.

Material enters the crushing chamber
Material enters the crushing chamber evenly through the feed port to avoid blockage.
Rotor rotates at high speed
The rotor is driven by a motor and rotates at high speed (usually 500-1000 rpm), and the hammer is fixed on the rotor.
Ball hammer impacts material
When the material enters the range of action of the hammer, it is hit by the high-speed rotating hammer at a very high speed (50-80 m/s) to obtain kinetic energy.
Material collides with the impact plate
The knocked-off material hits the impact plate (fixed or adjustable angle), resulting in the first crushing.
Rebound and secondary crushing
The material rebounds back to the rotor area and is hit by the hammer again, forming a cycle crushing until the particle size meets the requirements.
Discharging and screening
Qualified materials are discharged through the discharge port, and unqualified materials continue to be cyclically crushed.

2、Key mechanisms of the crushing process
Free crushing and rebound crushing
Free crushing: The material is hit by the hammer for the first time and collides with the impact plate.
Rebound crushing: After the material rebounds, it collides with the subsequent flying material or hammer again to enhance the crushing effect.
Shear and friction crushing
The material is subjected to shear force in the gap between the hammer and the impact plate, and cracks are generated inside the particles, accelerating crushing.
Particle size control
By adjusting the impact plate angle or rotor speed, the residence time of the material in the cavity and the number of collisions are controlled, thereby adjusting the discharge particle size.

3、Advantages of impact crusher
High crushing ratio
The crushing ratio of a single machine can reach 10-40, which is suitable for directly crushing large pieces of material into medium and fine particles.
Excellent particle shape
The crushed materials are mostly cubic, with low needle-like content, suitable for concrete aggregate production.
Strong adaptability
It can handle medium-hard and brittle materials such as limestone, coal gangue, and construction waste.
Energy saving and high efficiency
Compared with jaw crushers, energy consumption is reduced by about 30%, and production efficiency is increased by 20%-50%.
Long life of wearing parts
The hammer and impact plate are made of wear-resistant materials such as high manganese steel, with low maintenance costs.

4、Structure and classification of impact crushers
According to the number of rotors
Single-rotor impact crusher: simple structure, suitable for small and medium-sized production lines.
Dual-rotor impact crusher: higher crushing efficiency, suitable for large production lines.
According to the discharge method
Open impact crusher: open discharge port, suitable for coarse crushing.
Closed impact crusher: adjustable discharge port, suitable for medium and fine crushing.
According to the direction of the rotor
Reversible impact crusher: the rotor can rotate forward and reverse, extending the life of the hammer.

5、Application scenarios
Building materials industry: production of sand and gravel aggregates and machine-made sand.
Mining industry: crushing limestone, granite, etc.
Chemical industry: crushing coal gangue, gypsum, etc.
Construction waste treatment: crushing concrete blocks, bricks and tiles into recycled aggregates.