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Impact Crusher and its Working Principle

Oct. 24, 2020

1.  What is an impact crushers

Impact crushers are the method of naming, they are reducing large pieces of rock to smaller particle sizes. As the name implies, an impact crusher accelerates the feed material to a high speed, then throws fast-moving rocks against the walls of the crushing chamber and each other. This collision, impact, break the stone into smaller sizes.


They are usually divided into two main technologies. The traditional type has a horizontal shaft configuration and is therefore called a horizontal shaft impact crusher or shorter as an HSI crusher. The other is a vertical shaft centrifugal crusher called a vertical shaft impact crusher or VSI crusher.


A. Horizontal impact crusher (HSI)

In a conventional horizontal shaft impact rock crusher, the raw materials are crushed due to the high-strength impact generated by the rapid rotation of the hammer or rod fixed on the rotor of the crusher. Then, when the generated particles collide with the parts of the crusher, they will be further broken inside the crusher, resulting in a finer and better-shaped products. Horizontal shaft impact crushers come in various sizes and models, from large-capacity primary crushers to smaller machines.


B. Vertical shaft impact crusher (VSI)

The vertical impactor makes full use of the so-called rock crushing technology. In a vertical shaft impact crusher, crushable materials are fed through the center of the rotor, where they are accelerated to a high speed, and then discharged through an opening on the periphery of the rotor. When the material hits an external object, the material will be crushed due to the collision of the rocks. Vertical shaft impact crushers are usually used in the final stage of the crushing circuit, mainly in the aggregate production and construction industries, but also to prepare raw materials for mills in mining operations.

Impact Crusher

Impact Crusher

2. Working principle


Starting from the basic working principle of compression, compression is two surfaces squeezing each other, squeezing the material sandwiched between them. Impact crushing can have two changes: gravity and power. Because of the impact crusher has the consistent ability to uniformly crush aggregate through impact, it can produce the most uniform cube shape for the finished product. An example of gravity impact is smashing a rock onto a steel plate (similar to the situation when entering a self-grinding machine). The dynamic impact can be described as the material falling into a rapidly rotating rotor, where it is hit by a crushing blow from a hammer or impeller. Friction crushing is to reduce material through friction; mainly grinding method. Shearing is accomplished by following or crossing the cleavage line. It is possible, when needed, to use a combination of two or three principles for a crusher. In engineering, the measurement of rock hardness is of great help to the selection and selection of crushers.


3. How to choose a crusher?


Depending on the size of the fragment, it may be ready to enter the recycling process, or it may need to be broken down to obtain a granular size operable product. In this case, a hydraulic crusher installed on a crawler or wheel excavator will be used. In either case, manual classification of large pieces of steel, wood, plastic, and paper may be required to minimize the pollution of the final product.


DBM as an Impact Crusher Manufacturers provide several kinds of crusher, please ask us if you have any question.