Patent ID: 8262849

Claim:
An apparatus for manufacturing a fiber mass suspension, comprising: a first pulper having an un-pulped fiber material inlet, a water inlet, a rotor arranged to be driven by a motor, a screen plate leading to an accept outlet, and a reject outlet in receiving relation to material which does not pass through the screen, the first pulper for mixing together fiber material and water so as to produce a fiber mass suspension and for dividing the fiber mass suspension into an accept fraction and a reject fraction, the accept fraction being arranged to be forwarded to a further treatment process of the fiber mass suspension and the reject fraction being arranged to be supplied for further processing; a first secondary pulper having an inlet connected to the reject outlet of the first pulper so that the first secondary pulper is arranged in series with the first pulper, the first secondary pulper having a second rotor arranged to be driven by a second motor, a second screen plate leading to an accept outlet, and a reject outlet in receiving relation to material which does not pass through the second screen; wherein the accept outlet of the first secondary pulper is connected to an inlet of the first pulper or to a channel to which the accept outlet of the first pulper is also connected, and forms a continuous source of pulp to the inlet of the first pulper or the channel; a second secondary pulper having an inlet connected to the reject outlet of the first secondary pulper so that the second secondary pulper is arranged in series with the first secondary pulper, the second secondary pulper having a third rotor arranged to be driven by a third motor, a third screen plate leading to an accept outlet, and a reject outlet in receiving relation to material which does not pass through the third screen plate; wherein the accept outlet of the second secondary pulper forms a continuous source of pulp; wherein the reject outlet of the first pulper forms a continuous source of the reject fraction of the first pulper, which is connected by a first reject channel to the first secondary pulper inlet; wherein the reject outlet of the first secondary pulper forms a continuous source of the reject fraction of the first secondary pulper, which is connected by a second reject channel to the second secondary pulper inlet; and wherein the reject outlet of the second secondary pulper is connected to a further processing apparatus.