Rotary Milling Machinery

Rotary milling machinery or the rotary mills are one of the oldest machines still existing and functioning in almost the same way. They are the grinding mill, used for grinding the food grain.

The initial rotary mills were the rotary querns. It was a hand mill that had a fixed bed-stone. Over this was laid a runner stone with two bores one for the spindle and one for the handle. The upper stone was rotated with the handle continuously grinding the grain. The rotary mill emerged from it, the only difference being that it was bigger in size and rotated by the slaves. With further developments, the quality of grinding stones improved and so did the technology. The motion was powered by wind energy or water force called windmill and water mill respectively.

Even today, the basic technology remains the same. The same type of emery stones is used, at some places they have been replaced by cylinders or metal plates and powered by electricity. Ball mill, using rotating metal balls to crush the ores also fit into the category.