Solid material comminution or disintegration – Apparatus – With automatic control
Patent
1993-02-26
1994-06-28
Rosenbaum, Mark
Solid material comminution or disintegration
Apparatus
With automatic control
2412592, 384107, 384121, B02C 714
Patent
active
053239725
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to bearing systems for use in refiners or grinders for pulp suspensions and the like. More, particularly, the present invention relates to bearing systems for use in refiners which include a pair of opposed refining members which are axially adjustable and rotatable relative to each other thus defining a refining gap therebetween through which the pulp or raw material is passed.
BACKGROUND OF THE INVENTION
In connection with refiners or grinders which have relatively rotatable refining members defining a refining gap, during passage of the raw material or pulp through that gap, considerable axial forces are produced which act against the refining members which have been set at desired refining gap distances therebetween. This invention thus precisely relates to a refiner of the rotating disc type for refining papermaking pulp and the like in which the raw material which is to be refined or treated in some way is passed through such a refining gap defined by a pair of axially adjustable refining discs rotating relative to each other. These refining discs thus rotate relative to each other in a plane which is perpendicular to the shafts associated therewith. Thus, at least one of the refining discs is axially adjustable and mounted on a rotary shaft, which, in turn, in response to the pressure acting on the disc itself, is axially movable with the adjustable refining disc. The pulp or raw material itself can be wooden chips, bagasse, fiber suspensions or similar-type materials which are fed to the central portion of the refining gap, through which this material is radially accelerated by the action of centrifugal force generated by rotation of the discs themselves. The thus-processed material is then discharged after the refining operation through a peripheral opening between the discs into a surrounding casing.
Axial movement of the rotary shaft must be controlled in order to maintain the predetermined refining gap between the refining discs. The size of the gap varies depending upon the intended use of the refiner. In conventional pulp refiners, for example, the gap normally has a dimension of between about 0.1 and 1 mm, while in refiners for waste paper the gap size can be as large as about 2.5 min. In connection with other applications, the refining gap may be as small as about 0.05 mm. Pulp refiners of this type are disclosed in U.S. Pat. Nos. 4,082,233; 4,253,233; 4,283,016; 4,378,092; and 4,801,099.
The rapid acceleration of material through the narrow refining gap creates axial pressure forces, which tend to separate the refining discs from each other, thereby widening the refining gap, as a result of which the efficiency of the refiner can be seriously deteriorated.
When the refiners or grinders are part of a closed or pressurized system, for example, where they are used in the treatment of a liquid slurry, additional forces must be supplied to the drive mechanism which are greater than the axial pressure forces acting upon the discs. This additional force is required not only to drive the discs in order to obtain the desired refining or grinding, but also to drive the discs against the liquid friction or hydraulic brake forces acting on the discs, so that additional axial load variations on the rotary shaft are obtained.
When the effect of these forces on the axial position of the rotary shaft are not effectively controlled, the refiner will break down. Furthermore, the resistance against these pressure forces increases substantially with increasing diameter of the discs.
Because of the increasing demand of refining systems having high capacities, which thus require large diameter refining discs, for example of the magnitude of 150 cm or greater, the absorption of these axial pressure forces has become a widely recognized problem.
Newly developed refiners have a disc diameter of between about 165 and 170 cm, a rotational speed of between about 1500 and 3600 rpm, and a power of between about 15,000 and 50,000 kW.
In order to better appreciate
REFERENCES:
patent: 3977611 (1976-08-01), Sjobom
patent: 4073442 (1978-02-01), Virving
patent: 4402463 (1983-09-01), Kahmann et al.
patent: 4454991 (1984-06-01), Brenholdt
patent: 4801099 (1989-01-01), Reinhall
patent: 4890796 (1990-01-01), Reinhall
patent: 4915510 (1990-04-01), Arvidsson
patent: 5067660 (1991-11-01), Reinhall
Husar John M.
Rosenbaum Mark
Sunds Defibrator Industries Aktiebolag
LandOfFree
Bearing system in a refiner does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bearing system in a refiner, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bearing system in a refiner will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2372773