Solid material comminution or disintegration – Apparatus – Cooperating comminuting surfaces
Reexamination Certificate
1999-07-19
2001-10-09
Butler, Rodney A. (Department: 3725)
Solid material comminution or disintegration
Apparatus
Cooperating comminuting surfaces
C241S246000
Reexamination Certificate
active
06299084
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a device for treating lignocellulosic fibrous material in a refiner. with opposed refining means rotating relative to each other, which are provided with refining elements, which between themselves form a refining gap with a refining zone for working the material. More particularly, the present invention relates to such a device in which the lignocellulosic material is supplied through a central opening in the stationary refining element to a feed zone located radially inside the refining zone, and most particularly, to a feeding device for the material.
The device according to the present invention can be used during the manufacture of various types of mechanical pulps, such as refiner mechanical pulp (RMP), thermomechanical pulp (TMP), chemi-mechanical pulp (CMP) and chemi-thermomechanical pulp (CTMP). The starting material can be wood chips or more or less worked pulp.
BACKGROUND OF THE INVENTION
In connection with the above-referenced type of refiners, the inner portion of the feed zone the effect of centrifugal force on the supplied material is low. For this reason, the material supplied through the opening in the stationary refining element is generally not fed out sufficiently rapidly through the feed zone to the refining zone, which is located radially outward from the feed zone. As a result, the material can clog in the feed zone, which results in friction losses and non-uniform feeding, which in turn leads to deterioration in the pulp quality. For overcoming these problems, mechanical feeding devices of different types have been arranged in the feed zone, for example wings, blades, strips or the like. These devices, however, have not worked satisfactorily, particularly not when they have been designed so as to render the rotating refining means to reverse. It is thus often desired to be able to reverse the rotation of the refining means during pulp manufacture, since this can increase the life of the refining elements.
SUMMARY OF THE INVENTION
In accordance with the present invention, these and other objects have been realized by the invention of a feeding element for use in connection with a refiner for lignocellulosic fibrous material including a stationary refining member, a rotary refining member mounted for rotation in juxtaposition with the stationary refining member thereby forming a refining gap therebetween, a feeder for feeding the lignocellulosic fibrous material centrally to a central feed zone within the refining gap, and a refining zone extending radially outward from the central feed zone, the feeding element comprising a disk having a central portion, an outer circumference, an upper surface and a lower surface for mounting on the rotary refining member at a central location in the central feed zone, the disk including at least one radially projecting strip extending from ihe central portion of the disk towards the outer circumference of the disk, the at least one radially projecting strip including a body portion and a projecting portion extending laterally from the body portion at a location displaced from the upper surface of the disk for a major portion of the at least one radially projecting strip. In a preferred embodiment, the body portion includes a first side and a second side, and the projecting portion extends laterally from both the first and second sides of the body portion.
In accordance with one embodiment of the feeding element of the present invention, the feeding element includes at least two of the radially projecting strips. In accordance with another embodiment of the feeding element of the present invention, the height of the at least one radially projecting strip decreases in the radially outward direction.
In accordance with another embodiment of the feeding element of the present invention, the projecting portion extends laterally substantially to the outer edge of the radially projecting strip.
The feeding device according to the present invention solves the aforesaid problems in that it brings about effective feeding of the material, while simultaneously accelerating it through the feed zone, while at the same time allowing the refining means to reverse while maintaining its effectiveness. The effective feed also contributes to a reduction of the energy consumption of the refiner.
The feeding device according to the present invention comprises a disk with at least one radial strip, which along the greater portion of its upper edge is provided with a roof, which projects outward symmetrically on both sides of the strip. The feeding device is intended to be placed on the rotary refining means directly in front of the opening for the material supply in the stationary refining means.
Based upon the design of the present feeding device, the material which is supplied is accelerated outwardly by the strip or strips, while at the same time it is locked under the roofs of the strips. The width and length of the roof along the strips must be adapted so that it will not be too great, in which case it will prevent feeding of the material through the stationary refining means. The roof, however, must be sufficiently wide to ensure transport of the material outwardly through the feed zone to the refining zone.
REFERENCES:
patent: 3902673 (1975-09-01), Berggren
patent: 3957214 (1976-05-01), Berggren
patent: 4220290 (1980-09-01), Johansson
patent: 5040736 (1991-08-01), Obitz
patent: 1 090 937 (1960-10-01), None
Butler Rodney A.
Lerner David Littenberg Krumholz & Mentlik LLP
Valmet Fibertech Aktiebolag
LandOfFree
Feeding device for fibrous material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Feeding device for fibrous material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Feeding device for fibrous material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2608222