Solid material comminution or disintegration – Apparatus – Including means applying fluid to material
Patent
1997-01-27
1998-06-30
Rosenbaum, Mark
Solid material comminution or disintegration
Apparatus
Including means applying fluid to material
2412601, B02C 1812
Patent
active
057721319
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention concerns a kneader for the preparation of paper stuff.
It is known that in the paper industries equipment named kneaders are used for the preparation of paper stuff obtained by introducing waste paper in a water bath. The percentage of the paper in water can be between 1 and 6% in so-called low density kneaders while it can be from 12 to about 18% in so-called high density kneaders.
The action of the kneader consists in dividing the cellulose fibres and making an homogeneous suspension of the same fibres in water. Another important function is separating the ink which pollutes the paper, from cellulose fibres, in order to recover the fibres and reconstitute new paper free of ink.
The specific action of the kneader is a maceration and a continuous mixing up of the paper through a truncated conic rotor, with the larger base on the bottom of the tank, which presents several blades wound as a spiral longways the rotor axle.
The paper stuff is conveyed through the channel formed by the spirals of the blades to the bottom and then it goes up from the bottom to the top in order to go back again and for several times through said rotor. The separation of the paper from the ink is obtained by rubbing between contiguous cellulose fibres and said rubbing occurs during the descending of the paper stuff across the spirals of the channel formed by the rotor blades. It is therefore plain that longer is the permanence time of the paper stuff across the channel formed by the rotor blades, greater is the rubbing effect and therefore the separation and the homogenisation of the paper fibres. The rotors at present available, according to the actual technique used for the kneaders, are rotors with multiple principles with three or more blades having, as said, truncated conic form with the larger base towards the bottom and in which the section of every blade forms an angle with the rotor axis which is generally different from the right angle, according to a vertical section of the rotor which contains the axis of the same rotor.
Some rotors exist with acute angle between the blade section and the shaft axis with an opposite direction to the tank bottom. Nevertheless rotors exist too with blades which form an obtuse angle instead of an acute one as before defined. It has been observed that the rotors having an acute angle, as above defined, are more efficient in kneading compared to those having an obtuse angle. It has been observed too that the blade part, which works during the rotation, is just a small peripheral area compared to all the superficial extension of the blade having helicoidal form.
It has been observed also that worn rotors, to be replaced after many working hours, had the most part of the surface of the blades not abraded and so reasonably it has been concluded that, during the normal running of the kneader, the stream of the paper stuff did not regard the main part of the spiral and of the blade surface, but only the peripheral part which it was observed to be abraded.
Regarding what has been said above, that is to say the kneading of the paper is obtained by running between the contiguous cellulose fibres during the sliding along the spiral of the rotor, if only a little part of the stuff stream is canalised inside the rotor and if the main part remains out of the rotor by the centrifugal effect, it is evident that the kneading time must be superior compared to the theoretical time which could take a rotor where the blade works completely.
The same thing can be said for the absorbed power as it is clear that the material expelled from the rotor due to the centrifugal force has a resistance against the rotation of said rotor, and from this derives an higher absorption power.
SUMMARY OF THE INVENTION
The aim of the present invention is to overcome the mentioned disadvantages. It is intended to realise a kneader whose rotor has such characteristics to maintain the paper stuff in the spirals of the rotor itself, among the blades, so that the blades work in an uniform
REFERENCES:
patent: 3035781 (1962-05-01), Wallen
patent: 3402897 (1968-09-01), Willems
patent: 4460132 (1984-07-01), Thumm et al.
patent: 4607802 (1986-08-01), Lamort
Comer SpA
Rosenbaum Mark
LandOfFree
Kneader for paper stuff does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Kneader for paper stuff, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Kneader for paper stuff will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1851010