The impact mill is one of the latest inventions in the milling industry. Its design is meant to reduce on power consumption and maximize on efficiency. Its operation does not incorporate screening mechanisms as compared to the old models. However, this does not mean that it is less reliable and inefficient. In fact, it can be used to produce finer grades than the other types of mills. For this reason, it is applied in processes requiring both grinding and micro grinding operations. Its working mechanisms are quite sophisticated as compared to the other types such as hammer mills. The article goes ahead to describe basic operation principles of this machine and some of its advantages.
An impact mill is composed of an inlet unit, a pre-crush chamber and stator chamber. The stator contains a rotary shaft used for grinding and creation of air swirls. Once the desired product is fed into the input unit, it is pre-crushed at the pre-crush chamber. The crushing mechanisms in this chamber will not only crush the product but also accelerate it to the secondary grinding chamber. This is where the stator and rotor shaft are located. This chamber is located beside the primary chamber.
The stator is a sophisticated type of casing which contains the rotor shaft. It has numerous chambers arranged transversally along the rotor shaft. It also has U shaped chambers on the outside that form a cassette-like structure. The internal and external chambers are meant to introduce swirls within the secondary grinding chamber. The swirls lead to increased collisions between ground particles hence making them finer with time. Once the required particle size is achieved, the fine particles escape from the secondary chamber through the rotor clearance. The main advantages of the impact mill are low power consumption, higher reliability and finer grinding as compared to other models of mills.