The most versatile machine that is used to grind almost all types of biomass materials. The grinding takes place between the high speed swinging hammers and top / side liners. Once the particle size reduces to that of the perforated / bar type screen at the bottom. It will be discharged through the hopper. The fineness of the material can be controlled by changing the speed of rotor (hammer), content of serrations on liners, number of hammers and diameter of perforations on the screen.