Solid material comminution or disintegration – Apparatus – Cooperating comminuting surfaces
Patent
1993-09-27
1994-11-01
Eley, Timothy V.
Solid material comminution or disintegration
Apparatus
Cooperating comminuting surfaces
241260, B02C 706
Patent
active
053601750
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to refiners. More particularly, the present invention relates to refiners for manufacturing cellulose pulp. Still more particularly, the present invention relates to such refiners in which the raw material, such as wood chips, bagasse, fiber suspensions and the like, is processed in a gap between two opposed refining members which are relatively rotatable with respect to each other. Still more particularly, the present invention relates to such refiners in which at least one of the refining members is supported on a rotary refiner shaft driven by a motor, and in which an intermediate shaft is coupled in a non-rotary fashion between the rotor shaft of the motor and the refiner shaft.
BACKGROUND OF THE INVENTION
During start-up of refiners of the type described above, the driving motor, which is generally a synchronous motor, creates rather strong oscillating moments. These oscillations pass through a resonance frequency of the mechanically coupled shafts immediately before the working number of revolutions, or the synchronous speed, has been achieved. The excitation moment from the synchronous motor increases substantially during this passage through the resonance frequency, and the maximum moment which develops can exceed about 200 kNm. In view of the magnitude of the maximum moment, the refiner must be overdimensioned in relation to what is required during the other refiner operation conditions.
The present invention solves this problem in that the oscillation moment can be reduced to a level close to that during normal operation conditions.
SUMMARY OF THE INVENTION
These and other objects have now been accomplished by providing a refiner for the treatment of cellulose-containing material between a pair of opposed, relatively rotatable refining members, at least one of which is rotatably supported on a refiner shaft, in which the refiner includes a motor, a rotor shaft driven by the motor, an intermediate shaft interposed between the refiner shaft and the rotor shaft for transferring the drive moment therebetween, a first coupling member rigidly connecting one end of the intermediate shaft to the rotor shaft, a second coupling member rigidly connecting the other end of the intermediate shaft to the refiner shaft, outer pipe means concentrically disposed about the intermediate shaft for providing stiffness against torsion created in the refiner, the outer pipe means interconnecting the first and second coupling members, and friction damper means interposed between one end of the outer pipe means and at least one of the first and second coupling members, whereby oscillations in the refiner are reduced thereby.
In accordance with one embodiment of the refiner of the present invention, the other end of the outer pipe means is rigidly connected to the other of the first and second coupling members. In a preferred embodiment the outer pipe means has a first degree of rigidity and the intermediate shaft has a second degree of rigidity, the first degree of rigidity being from 3 to 15 times greater than the second degree of rigidity, preferably from 8 to 10 times greater than the second degree of rigidity.
In accordance with one embodiment of the refiner of the present invention, the friction damper means includes at least two friction surfaces in direct contact with each other. Preferably, the friction damper means is arranged so that these at least two friction surfaces begin to slide relative to each other at a torque of between about 30 and 100 percent of the effective output of the motor at full load.
In accordance with a preferred embodiment of the refiner of the present invention, the friction damper means includes radial brake disk means projecting radially from the first end of the outer pipe means, brake block means in frictional contact with the radial brake disk means, and tightening means for urging the brake block means against the radial brake disk means. Preferably, the brake block means comprises a pair of brake blocks on either side of t
REFERENCES:
patent: 3776079 (1973-12-01), Steinberg et al.
patent: 4061279 (1977-12-01), Sautter
patent: 4082139 (1978-04-01), Davis
patent: 4379707 (1983-04-01), Fisher
patent: 4773602 (1988-09-01), Rossler
patent: 5195684 (1993-03-01), Radzins
Eley Timothy V.
Sunds Defibrator Industries Aktiebolag
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