When the feed is farm-made

摘要

Hammer-mills are eas-ier to maintain, they can process a wider variety of materials and have a greater output capacity for their size. But they also need more horsepower, are noisier to operate and create more dust. With roller-mills, the range of particle sizes tends to be narrower and the lower horsepower requirement means that less energy is used (other sources say, rolling consumes only half the power that grinding does). Against the fact they are quieter and less dusty, they also involve a higher initial investment and their maintenance needs include a periodic re-grooving of the rolls.