Shredding system

A shredder (1) for comminuting organic material to form shreds, comprising one introduction funnel (5) for supplying organic material, a shredding chamber (2) provided with plural rotatable cutting blade groups (12) configured for shredding the supplied organic material into shreds and a fan (7) in a fan chamber (6) which is connected to the shredding chamber (2) via a centrally situated passage (4) configured for passing the shreds formed, said passage being provided between the shredding chamber and the fan chamber, the shredder further comprising a discharge opening (8) connected to the fan chamber, wherein the fan (7) is configured to generate a suction force which sucks the shreds out of the shredding chamber (2) via the passage (4), and wherein the fan removes the shreds from the fan chamber (6) via the discharge opening (8), the shredder further comprising a shaft (10) having a periphery on which at least two adjacent cutting blade groups of the plural rotatable cutting blade groups (12) are fixedly fitted and are rotatably arranged in front of an anvil (11), wherein said plural rotatable cutting blade groups (12) each comprise several splitting blades (13) which are intended for splitting supplied organic material substantially along a direction of introduction of the material, wherein said fan (7) is fitted on the same shaft (10) as that on which said cutting blade groups (12) are arranged and wherein the shredder (1) further comprises obstructions configured to counteract a shred-conveying airflow in a direction of the passage (4) to increase a residence time of the shreds, and wherein the several splitting blades (13) comprise bevels of cutting faces (14) sloping away from the passage (4) and the fan (7) as the splitting blades (13) contact the anvil (11), the bevels of the cutting faces (14) being configured such that the shreds formed by the several splitting blades (13) and the anvil (11) are flung in a direction away from the passage (4).