1. Hammer crusher introduction
The hammer crusher is a machine that crushes materials in the form of impact and is divided into two forms: single rotor and double rotor. The single rotor is further divided into reversible and irreversible types. At present, single rotor hammer crushers and ring hammer crushers are widely used.
Hammer crushers are mainly used for various brittle materials with compressive strength not exceeding 100 MPa and humidity not greater than 10%-15%. Because of its particularly simple and compact structure and high crushing ratio under impact, this type of crusher is widely used in coal mines, coal beneficiation plants and industrial sectors such as power plants, cement, metallurgy, refractory materials and quarrying. In coal processing plants, it is mainly used for crushing fine coal or in situations where the lump coal content in the product is not high.
2. Hammer crusher working principle and structure
2.1 Hammer crusher working principle
The crusher rotor rotates at high speed under the drive of the electric motor. After entering the crusher, the material is immediately crushed by the impact of the high-speed rotating hammer head. After crushing, the material is crushed by the impact of the hammer head to the liner and grate bar inside the machine shell at high speed. The material smaller than the gap of the grate bar is discharged from the gap, while the material with larger size continues to be impacted by the hammer head in the crushing chamber until it is crushed and discharged through the gap of the grate bar.
2.2 Hammer crusher structure
The single-rotor hammer crusher is mainly composed of main frame, rotor, main shaft, hammer heads, grate, adjusting frame, and coupling(Figure 1).
The shell of the hammer crusher is a box-shaped structure welded with steel plates, divided into upper and lower parts along the center of the axis, which are connected by bolts, and there is a feed opening above the shell. In order to prevent the inner wall of the box from being worn and deformed by the impact of the material, there are protective liners inside the shell. There are two kinds of turntable, triangle and round. The three angles of triangle turntable are very easy to wear, and if found in time, it is easy to drop the hammer, and its service life is not as long as round turntable. There are 6 shafts on the rotor, and the hammer heads are staggered on the rotor through the shafts, and there is an isolation sleeve between the hammer heads. When the rotor rotates at a high speed, the hammer head breaks the material under the action of centrifugal force. The rotor shaft is supported by bearings at both ends, and the bearings are installed on both sides of the box and fixed with bolts. The grate bar is arranged on the grate bar frame with the rotor shaft as the center, and the grate bar frame is fixed by bolts on the box. The lower part of the box is equipped with a through shaft with two eccentric wheels. Turn the handle on both sides of the machine, make the eccentric wheel turn an angle, then the grate rack can be raised or lowered, so that the gap between the hammer head and the grate can be adjusted, and the required product size can be obtained. It is not necessary to stop the machine when adjusting.
3. Installation, Use and Maintenance
In addition to the general requirements for the installation, use and maintenance of the hammer crusher, the following points must be emphasized here.