D-type Pulper is mainly composed of D-shape tank body, rotor, accept plate, bracket, motor and shield, etc.When water injected into the tank reaches half of the volume, start the motor, then uniformly feed pulp board, broke or waste paper into the tank. When rotor rotates, pulp material runs towards to surroundings from the center, vortex forms in the center area. Under strong hydraulic force and shearing action, materials are exposed to intense friction and rub, together with force from the rotor, pulp board or broke are defibered to single fiber in wet condition. After defibering and separating, pulp flows out from the screen holes while foreign matters and heavy rejects fall into the sediment tank and then discharged regularly.When continuously pulping, foreign matters and heavy rejects go into sediment tank and are discharged after process in reject separator. For the special structure of such hydrapulper, when rotor rotates, pulp flow is stopped by the flat wall of D shaped tank and then change flow to the center. Thus, circulation route of pulp is shortened, bringing higher efficiency of pulping. Those left paper scraps and fiber bundles will be further deflaked in the clearance between rotor and screen plate. Pulping blades are specially designed at the end so that the screen holes will not be plugged. Ragger is equipped when pulping for continuously removing ropy rejects, greatly extend the continuous operation of pulper. That is how the pulping efficiency is improved.