Tangential discharge disk refiner

Abstract

A papermaking refiner has two stationary disks mounted to the support structure of a fixed housing. A rotating disk is mounted on a shaft which extends through the housing. The support structure allows stock to circulate on both sides of the disk support structure, thus balancing fluid pressures on both sides of the fixed disk and preventing thermal gradients for reduced deflection of the disks. The incoming stock is centrifugally accelerated in a shroud which separates and traps tramp metal or the like before the stock passes to the refiner disks. The shroud has passageways which allow the rotating fluid to enter a reservoir which surrounds the drive shaft and feeds the gaps between the rotor and the stationary plates.

Description

CROSS REFERENCES TO RELATED APPLICATIONSSTATEMENT AS TO RIGHTS TO INVENTION MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENTBACKGROUND OF THE INVENTION[0001]The present invention relates in general to refiners for treating paper pulp fibers to condition the fibers prior to delivery to a papermaking machine and to refiners for handling stock having a consistency of about 3 to about 6 percent fiber by weight.[0002]Disc refiners are used in the papermaking industry to prepare paper pulp fibers for the forming of paper on a papermaking machine.[0003]Paper stock containing three to six percent dry weight fibers is fed between closely opposed rotating discs within the refiner. The refiner discs perform an abrading operation on the paper fibers as they transit radially between the opposed moving and non-moving refiner discs. The purpose of a disc refiner is to abrade the individual wood pulp fibers.[0004]Processing of fibers in a low consistency refiner may be performed on both chem...

AI Technical Summary

Benefits of technology

[0010]The disk refiner of this invention improves the overall performance of a twin disk refiner of the type having two stationery disks and a single rotor on which are mounted opposed refiner disks which oppose the stationery disks. As is conventional, one of the stationary disks is fixed and the other is mounted for axial movement towards the other stationery disk. In the past the shaft on which the rotor was mounted was movable axially to position the rotor between the stationery disks as the distance between the stationery disks was adjusted. In the disk refiner of this invention the rotor is mounted for axial movement to a spline. The spline forms part of a drive shaft connected to a drive motor. The spline mounting facilitates hydrodynamic balance of the rotor between the stationary disks.

[0011]The disk refiner supports the stationery disks on less rigid structure but is designed to allow stock to circulate on both sides of the disk support structure. This improves alignment between the rotor mounted refiner disks and the stationary refiner desks in two ways: by balancing fluid pressures on both sides of the stationery mounting structures for the refiner disks, and by preventing thermal gradients from causing deflection of these same structures.

[0012]In order to prevent damage to the refiner plates due to tramp metal, the incoming stock is centrifugally accelerated in a shroud which separates and traps tramp metal or the like before the stock passes between the stationery and rotating refiner disks. The shroud has passageways which allow the rotating fluid to enter a reservoir which surrounds the drive shaft and feeds the gaps between the rotor and the stationary plates. By pre-rotating the stock before it flows to the rotor, stock is more easily balanced between both sides of the rotor because the rotating stock can pass through openings in the rotor to reach the rotor back side.

[0013]It is a feature of the present invention to provide a disk refiner with reduced wear of the refiner plates.

[0016]It is a yet further feature of the present invention to provide a lighter weight refiner which supports with less deflection the stationary refiner plates.

[0017]It is another further feature of the present invention to provide a double disk refiner with lower maintenance cost.

Problems solved by technology

Raw fibers are relatively stiff and have relatively low surface area when the primary wall is intact, and thus raw fibers exhibit poor bond formation, with the result that paper which is made of raw fibers has limited strength

Images