Self-grinding device of lump in rotary drum granulator

The invention relates to a self-grinding device of a lump in a rotary drum granulator. The self-grinding device comprises a fragment screening mesh which is connected to a discharge end of the rotary drum granulator; the fragment screening mesh is completely coated on a port of the discharge end of the rotary drum granulator; and a plurality of fragment screening strips are coaxially, concentrically and evenly connected to the outer circumference of the granulator at intervals to form the fragment screening mesh, so as to achieve self-grinding of the lump of the granulator. The self-grinding device is simple in structure, low in production cost, low in artificial labor intensity, stable in production technology and high in rotate rate; a power source and equipment do not need to be added; the energy is saved and consumption is reduced; and the granulating output and the granulating quality are improved.