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US 2004/0026050 A1Published application
Method and Equipment for pulp fractionation in a paper or board machine
AssigneeMetso Paper, Inc.
InventorKari Kokkonen
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AssigneeMetso Paper, Inc.
InventorKari Kokkonen
Estimating the term…
The invention concerns a method and equipment for pulp fractionation in a paper or board machine. In the method, virgin stock is conducted to the paper or board machine and further to a centrifugal cleaner installation (12) into its first centrifugal cleaner step (12a1). From the first centrifugal cleaner step (12a1) the accept is conducted into a multi-layer headbox (10) to form a layer of the web determined according to the concerned fraction. From a second step (12a2) and/or from lower steps (12a3, 12a4 . . . 12an) of the centrifugal cleaner installation (12) a second fraction or more fractions are conducted into the multi-layer headbox (10) to form a second layer or other layers of the web, which are determined according to the pulp fractionation taking place in the concerned second step or lower steps.
Method for fractionation of pulp in a paper or board machine, whereby in the method virgin stock is conducted to the paper or board machine and further to the first centrifugal cleaner step (12a1) of a centrifugal cleaner installation (12), characterised in that in the method the accept is conducted from the first centrifugal cleaner step (12a1) into a multi-layer headbox (10) to form a layer of the web determined by the fractionation in question, and that a second fraction or more fractions are conducted from a second step (12a2) and/or from lower steps (12a3, 12a4 . . . . . . 12an) of the centrifugal cleaner installation (12) into the multi-layer headbox (10) to form a second layer or other layers of the web, which are determined based on the fractionation taking place in the concerned second step or lower steps.
Method according to any one of the preceding claims, characterised in that in the method a deaeration tank (11) is used, which is formed of several sections, whereby there is a separate supply and discharge fitting (a1, a2;
Method according to any one of the preceding claims, characterised in that in the method the final fractionation result is finished in a power screen (14a1, 14a2, 14a3) fitted in a fitting (a2′, a2″, a4) in between the deaeration tank and the multilayer headbox, and the accept of the power screen is conducted as supply into the bypass manifold (J1, J2, J3) of the concerned layer in the multilayer headbox, and the reject is conducted back through the wire pit (13) into the centrifugal cleaner installation (12).
Equipment for fractionation of pulp in a paper or board machine, characterised in that the equipment includes means for feeding virgin stock to the tail water, a centrifugal cleaner installation (12) and a multi-layer headbox (10), whereby there is a fitting (b1, b1) for the virgin stock admixed with the tail water to the first step (12a1) of the centrifugal cleaner installation (12) to conduct the virgin stock admixed with the tail water to the first step (12a1) of the centrifugal cleaner installation (12) as supply, and that from the first step (12a1) of the centrifugal cleaner installation (12) there is a fitting (a1) for the accept of the first step (12a1) while the concerned pulp fraction is supplied to the multi-layer headbox (10) to form a certain layer of the web, and that the equipment includes at least one other fitting (a3) from the second step (12a2) and/or from some lower step/steps (12a3, 12a4 . . . . ) of the centrifugal cleaner installation (12) to the multilayer headbox (10) to form a second layer or other layers of the multilayer web.
Equipment according to the preceding claim, characterised in that the fitting for accept of the first step of the centrifugal cleaner installation (12) is conducted to the deaeration tank (11), and the fitting (a2) leading out of the deaeration tank (11), along which fitting the accept of the first step (12a1) of the centrifugal cleaner installation (12) is moved, is branched off into branch fittings (a2′, a2″), which further join with bypass manifolds (J1, J3) of the multi-layer headbox (10) to form the top and bottom layers of the web.
Equipment according to any one of the preceding claims, characterised in that the fitting (a2′, a2″;
Equipment according to any one of the preceding claims, characterised in that from the power screen (14a1, 14a2, 14a3) there is a return fitting (f1, f2, f3) for the reject into the wire pit (13).
Dependencies are inferred from the claim text.