BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a conical-disk refiner showing the refiner plates for the flat section and the conical section.
FIGS. 2A-C are illustrations of a prior art refiner plate for the conical section of a conical-disk refiner.
FIGS. 3A-C are illustrations of an embodiment of a refiner plate having a triangular injector inlet in a conical-disk refiner.
FIG. 4 is an illustration of another embodiment of a refiner plate having a triangular injector inlet.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a partial cross-sectional view of the configuration of refiner plates in a conical-disk refiner. There are two refining sections: conical section 102 and flat section 104. There is a gap 106 between conical section 102 and flat section 104 where the feed transitions from one refining zone to the next. Conical section 102 contains a rotor plate 108 and a stator plate 110. Flat section 104 similarly has a rotor plate 112 and a stator plate 114.
In general terms, lignocellulosic material enters the flat section at entrance 116. From there, the lignocellulosic material enters refining zone 118. Refining zone 118 contains a pattern of bars and grooves, which provide impacts or pressure pulses to facilitate separation and fibrillation of the fibers. As the lignocellulosic material is worked between the plates, steam may be generated.
From refining zone 118, the lignocellulosic material flows through the gap 106 to the injector inlet 120 of rotor plate 108 in conical section 102. The feed zone forces the lignocellulosic material forward and distributes the material amongst the refining section 122, which contains a pattern of bars and grooves to provide impacts or pressure pulses to facilitate separation and fibrillation of the fibers. After being worked between the rotor 108 and stator 110 in refining zone 122, the refined lignocellulosic material exits at exit 124.
FIGS. 2A, 2B, and 2C show a prior art configuration of an inlet in a rotor plate in a conical section of a conical-disk refiner. FIG. 2A shows a cross-sectional view of A-A of FIG. 2B. FIG. 2C shows a cross-sectional view of C-C of FIG. 2B. In these figures, the same items share the same numbers.
In FIG. 2A, the lignocellulosic material flows from the gap 206 to the injector inlet 220 of rotor plate 208. The feed zone forces the lignocellulosic material forward and distributes the material amongst the refining section 222, which contains a pattern of bars and grooves to provide impacts or pressure pulses to facilitate separation and fibrillation of the fibers. After being worked between the rotor 208 and stator 210 in refining zone 222, the refined lignocellulosic material exits at exit 224.
FIG. 2B shows an overview of a prior art configuration of an inlet in a rotor plate in a conical section of a conical-disk refiner. The inlet protrusions 220 have an approximately square base with a triangular portion pointed toward refining section 222. The inlet protrusions 220 cause frictional forces 230. FIG. 2C shows inlet protrusions 220 and frictional forces 230 and centrifugal forces 232. Although it is believed that the frictional and centrifugal forces, as shown in FIGS. 2B and 2C, are more or less accurate, they are shown for illustrative purposes only.
FIGS. 3A, 3B, and 3C show an embodiment of an inlet having a substantially triangular protrusion in a rotor plate in a conical section of a conical-disk refiner. Although shown in an embodiment related to the conical section of a conical-disk refiner, an inlet having a substantially triangular protrusion may be employed in a flat section of a conical-disk refiner, in a disk refiner, or in a conical refiner. Similarly, an inlet having a substantially triangular protrusion may be employed in either a rotor plate or a stator plate, even though depicted with respect to a rotor plate in the conical section of a conical-disk refiner.
FIG. 3A shows a cross-sectional view of A-A of FIG. 3B. FIG. 3C shows a cross-sectional view of C-C of FIG. 3B. In these figures, the same items share the same numbers.
In FIG. 3A, the lignocellulosic material flows from the gap 306 to the injector inlet 320 of rotor plate 308. The feed zone forces the lignocellulosic material forward and distributes the material amongst the refining section 322, which contains a pattern of bars and grooves to provide impacts or pressure pulses to facilitate separation and fibrillation of the fibers. The precise pattern of bars and grooves is unimportant to the present invention, and any conventional or nonconventional pattern is sufficient, so long as commercially practical and/or technically feasible. After being worked between the rotor 308 and stator 310 in refining zone 322, the refined lignocellulosic material exits at exit 324.
FIG. 3B shows an overview of an embodiment configuration of an inlet having a substantially triangular protrusion in a rotor plate in a conical section of a conical-disk refiner. As shown, there are a refining zone 322 and an inlet zone containing the substantially triangular inlet protrusion 320. The substantially triangular inlet protrusion 320 has a base 360, side 362, and side 364. In alternative embodiments, there are two or more substantially triangular inlet protrusions on the refiner plate.
Preferably, the base 360 and the sides 362 and 364 are substantially straight as depicted in the embodiment shown in FIG. 3B, although greater amounts of deviation from substantially straight are permitted in other embodiments. For example, they may be individually or collectively arcuate, jagged, or some other curvilinear form. As shown, the base 360 preferably extends beyond plate's base 370, although the base 360 may terminate in the same plane of the termination of base 370. Alternatively in a separate embodiment, base 370 may extend beyond base 360 of the substantially triangular protrusion. In FIG. 3B, the base 360 is substantially parallel to the base 370. In other embodiments, the base 360 is not substantially parallel to the base 370.
In an embodiment, the base of the triangular section of the feeding protrusion may preferably cover approximately one-third of the arc length of the segment (or approximately one-sixth when two protrusions are present). For example, the range for the total length of bases for all protrusions may cover 20 to 45%, preferably 25 to 40%, and more preferably 30-35% of the arc length of the segment inlet, and all sub-ranges therebetween.
As shown in FIG. 3B, the substantially triangular shape has three angles: angle 350, angle 352, and angle 354. These angles correspond to the three corners of the substantially triangular shape. As shown in FIG. 3B, angles 350 and 352 are approximately equivalent, forming an approximately isosceles triangular protrusion. In other embodiments, the substantially triangular protrusion 320 may be a substantially equilateral triangular protrusion or a substantially scalene triangular protrusion. One of angles 350, 352, and 354 may approximately be a right angle.
Preferably, angles 352 and 350 are between 15° and 75°, more preferably between 30° and 60°, and even more preferably between 40° and 50°, and all sub-ranges therebetween. As shown in FIG. 3B, the corners corresponding to each of angles 350, 352, and 354 are preferably substantially rounded. It is believed that rounding the corners minimizes the likelihood of being chipped or damaged by contraries in the feed material. In other embodiments, the angles are not substantially rounded.
Preferably, the feed angle at the inlet of the triangle is within the range of 15-75°, and it is preferable to maintain a strong enough construction to avoid a feeding element that is structurally weak and may break in the refiner. In addition, the draft angle, or the side angle on the triangles relative to the axis running from the center of the refiner disk and across the base plate should preferably—though not necessarily—be as close to 0° as possible, subject to limitations inherent in the manufacturing process. In fact, a negative draft angle is preferable because it would increase the positive feeding effect by reducing the tendency to throw material into the stator side.
In FIG. 3B, angle 354 corresponds to the apex of the substantially triangular shape 320. In some embodiments, the apex may protrude, either substantially or not, into the refining zone. As shown in FIG. 3B, the apex does not protrude into refining zone 322.
As shown in FIG. 3B, the substantially triangular inlet protrusion 320 causes frictional forces 330. FIG. 3C shows the substantially triangular inlet protrusion 320 and frictional forces 330 and centrifugal forces 332. Although it is believed that the frictional and centrifugal forces, as shown in FIGS. 3B and 3C, are more or less accurate, they are shown for illustrative purposes only. However, it should be noted that the present invention is not limited to the direction or magnitude of any particular frictional or centrifugal force.
FIG. 3C depicts a pattern of bars 380 and grooves 382. The top 366 of the substantially triangular protrusion is depicted as taller than the grooves. In other embodiments, the top 366 may be substantially the same height as bars 380 (or some subset of bars 380). In yet further embodiments, the top 366 may be shorter than bars 380 (or some subset of bars 380).
As shown in FIG. 3C, the substantially triangular protrusion 320 has a substantially rectangular cross-section formed by top 366 and sides 368 with rounded corners. In other embodiments, the substantially triangular protrusion 320 has a substantially trapezoidal—either isosceles or not—cross-section. In yet further embodiments, the substantially triangular protrusion does not have rounded corners.
FIG. 4 shows another embodiment of an inlet of a refiner plate having a substantially triangular protrusion. The refiner plate's feed zone forces the lignocellulosic material forward and distributes the material amongst the refining section 422, which contains a pattern of bars and grooves to provide impacts or pressure pulses to facilitate separation and fibrillation of the fibers. Some of the refining bars are labeled as 480. The precise pattern of bars and grooves is unimportant to the present invention, and any conventional or nonconventional pattern is sufficient, so long as commercially practical and/or technically feasible. In the embodiment shown in FIG. 4, the bars 480 are substantially parallel, and the inlets of the bars are arcuate from the centerline of the plate to the left and right edges of the plate. Whether the inlets of the bars 480 form an arc or some other configuration is generally a design choice based on operational considerations, such as composition of the lignocellulosic material, refiner capacity, refiner type, etc.
As shown in the embodiment of FIG. 4, the substantially triangular protrusion 420 has three sides: base 460, side 462, and side 464. Base 460, which is substantially straight, protrudes beyond the plate's base 470. In other embodiments, base 460 is not substantially straight. For example, the base of the substantially triangular protrusion may be arcuate, jagged, or some other curvilinear form. Sides 462 and 464 are generally arcuate, though they also may be substantially straight, jagged or some other curvilinear form. Furthermore, sides 462 and 464 may form an arc that bows outwardly from the center of the substantially triangular protrusion, rather than inwardly as depicted.
Side 462 and base 460 meet at corner 490. As shown, corner 490 is slightly rounded, although it may be more or less rounded in other embodiments. As depicted in this embodiment, the substantially triangular protrusion has an apex 494 that protrudes into refining zone 422. Furthermore, apex 494 does not form a corner; rather, apex 494 transitions into multiple refining bars: refining bar 496 and refining bar 498. In other embodiments, apex 494 transitions into a single refining bar or into more than two refining bars.
The transition, if any, from the substantially triangular protrusion into a refining bar may be relatively smooth or disjointed. That is, the surface of the refining bars 496 and 498 may not be in substantially the same plane as the surface of the substantially triangular protrusion 420. And if they are not in the same plane, the transition between the refining bars and the substantially triangular protrusion may be gradual or sudden.
Although FIG. 4 depicts a single substantially triangular protrusion 420, a single refiner plate may contain multiple substantially triangular protrusions in accordance with other embodiments
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Patent Application
20080041997
