The blower is an important part of the impact crusher. When the material enters the impact area of the blower, it is crushed by the high-speed impact of the blower and is thrown to the impact plate installed above the rotor to be broken again, and then from the impact liner. Bounce back to the area of impact of the blower and break again. It can be seen that the blow bar is in direct contact with the material. The shape and fixing method of the blow bar have a certain influence on the crushing. This article mainly introduces the two shapes and three fixing methods of the blow bar.
Two shapes of blow bars
There are two types of blow bars, one is straight blow bars and the other is crescent blow bars.
The crescent plate hammer is more advantageous because it can ensure that the material hits vertically, the impact is greater, and the crushing efficiency is high. In addition, the impact surface is larger than that of a straight hammer, and it is more durable.
Blind hammer fixing method
The plate hammer needs to be fixed on the rotor in the impact crusher. There are three ways to fix the plate hammer:
1. Bolt fixing
The blow bar is axially inserted into the corresponding slot of the rotor from the side of the rotor. In order to prevent axial movement, the two ends are positioned by pressing plates. Since the fastening bolts are removed, the reliability of the blower work is improved. The centrifugal inertia force generated during the rotation of the hammer and the reaction force during impact and crushing are used for fastening and self-locking, and a replaceable structure is made for the wear-prone parts of the rotor, so the assembly and disassembly are simple and easy to manufacture.
However, the bolts exposed on the striking surface are easily damaged, and the bolts are subjected to greater shearing force, and once they are cut off, it will cause serious accidents.
2. The pressure plate is fixed
The blow bar is inserted into the groove of the rotor from the side, and the two ends are pressed by pressing plates. However, this fixing method makes the blow bar not strong enough, and the blow bar is easy to loosen during work. This is because the production and processing requirements of the blow bar are very high and the manganese is high. Alloy materials such as steel are not easy to process.
3. The wedge is fixed
The wedges are used to fix the blow bars on the rotor. Under the action of centrifugal force during work, this fixing method can ensure that the faster the rotor speed, the stronger the blow bars are fixed, and the work is reliable, and it is more convenient to remove and replace. This is a better fixing method for the hammer at present, and all countries are adopting this fixing method.
The wedge is made of cast steel, which has certain toughness and plasticity, high strength and hardness, and good mach inability.