Edge Runner Mill.
Principle:
It works on the principle of Crushing and Attrition.
Diagram:
Construction:
Also known as the Chilean mill or Roller stone mill.
It consists of one or two heavy steel or granite rollers mounted on a horizontal shaft and turned round a central vertical shaft on a bed of steel or granite.
The stones may vary from 0.5 to 2.5 m in diameter, the larger size weighing up to about 6 tonnes.
Working:
The material to be ground is kept in the path of the runner by scrapers.
The reduction is partly due to crushing: by the weight of the stones, but more to friction between the surfaces of contact between the runners and the bed stone.
Application:
Edge runner mills are gradually being replaced by more sophisticated machines.
Used particularly for reducing extremely tough and fibrous materials – roots and barks to the form of powder.
Commonly Asked Questions.
What is size reduction? Write Principle, Construction and working of the Edge Runner Mill.