DESCRIPTION
DISK REFINER HAVING SLIDING RIGID MULTIPLE DISKS
The present invention relates to disk refiners, and more particularly to disk refiners for providing a low intensity treatment of pulp fiber to increase the strength characteristics of the pulp and reduce the amount of specific energy required during refining.
It has recently been shown that low intensity treatment of certain pulp fiber increases the strength of characteristics of the pulp while reducing the amount of specific energy required. In this context, intensity for a given throughput is proportional to the horsepower per inch of refiner bar crossings, as disclosed in U.S. 696,904, filed January 31, 1985, in which specific operational parameters of a refining system are sensed to control the refiner disk spacing by way of a gear otor. A reduction in intensity, therefore, may be accomplished by increasing the number of refining surfaces in a given refiner. is the object of the present invention to provide a new and improved multi-disk refiner for low intensity treatment of pulp fiber.
The above object is achieved, according to the present invention, in providing an increase in the number of refining surfaces by mounting several rigid refiner disks in a manner so as to provide each disk with complete freedom of axial movement. The rotating refiner disks can be mounted so as to be axially slidable on a torque trans¬ mitting section of a shaft so that rotational forces can be transmitted to the disks while an axial motion thereof is not restrained. The torque transmitting section of the shaft may be splined or have a geometrical cross- sectional (e.g. square, triangular or other polygon) and the rotatable disks may have correspondingly shaped central openings receiving the respective torque trans¬ mitting section. Non-rotatable or fixed refiner disks can be supported by several support leraens (e.g. pins, quide rails and the like) which prevent rotation of the disk, but permit each such refiner disk to slide in the
axial direction. The shaft and the stator support elements can be constructed of a hard material, and the sliding members may be constructed of softer, wearable material. The sliding members may also be molded from a structural plastic material. The non-rotating disks each include a central aperture for receiving the shaft therethrough and for supporting the flow of paper stock and the rotating disks each include ports to permit the paper stock to flow therethrough and be properly distributed to each pair of refiner disks.
The refiner may be loaded to the desired power by axially adjusting the last stationary element of a series of refiner disks.
Inasmuch as the refiner disks are not axially secured to the refiner shaft or housing, the number of plates may easily be increased or decreased in the refiner to match the process requirements.
Also, inasmuch as there is no limitation on the axial movement of the refiner disks, a large number of plates may be added to a refiner to increase the overall capacity of a given size of the refiner. Therefore, a smaller diameter refiner having many refiner discs may be used in place of a large refiner having fewer discs. This reduces the capital expense for large horsepower, low speed motors which are required by the larger diameter refiners.
Other objects, features and advantages of the invention, its organization, construction and operation will be best understood from the following detailed description, taken in conjunction with the accompanying drawings. ON THE DRA ING'S
FIG. 1 is a fragmentary sectional view of a refiner constructed in accordance with the present invention; FIG. 2 is a fragmentary enlarged view of a portion of the refiner illustrated in FIG. 1;
FIG. 3 is a partial sectional view taken sub¬ stantially along the parting line III-III of FIG. 1;
FIG. 4 is a fragmentary sectional view illustrating a shaft having a square torque transmitting section; FIG. 5 is a fragmentary sectional view illustrating a shaft having a triangular torque transmitting section;
FIG. 6 is a fragmentary sectional view illustrating a shaft having a hexagonal torque transmitting section;
FIG. 7 is a fragmentary sectional view illustrating an arcuate guide rail support structure;
FIG. 8 is a fragmentary sectional view illustrating a trapezoidal guide rail support structure; and
FIG. 9 is a fragmentary sectional view illustrating an oval support element structure. Referring to the drawings, a refiner, constructed in accordance with the present invention, is generally illustrated at 10 as comprising a first housing part 12 having a recess therein which, with a second housing part 14 defines a refining chamber 16. The refiner comprising a paper stock flow path including a paper stock input 18 to the refining chamber 16 and a paper stock output 20 from the refining chamber 16.
The housing part 12 comprises a bore 22 with a bearing 24 therein supporting a shaft 26 for rotation. The shaft 26 includes a splined section 28 for mounting a plurality of rotatable refiner discs 30 each of which has a central aperture 32 co plemental to the spline 28.
As seen in each of the figures, each rotatable disc 30 comprises a plurality of ports 34 for supporting a flow of stock.
Alternately mounted with the rotatable disc 30 is a plurality of refiner discs 36 each of which is provided with a central aperture 38 for receiving the shaft there¬ through and for supporting a flow of paper stock. Each of the plates 36 further comprises a plurality of bores 42 for receiving a respective pin 44 mounted to the housing part 12.
Each of the rotatable refiner discs 30 is axially
slidable along the spline section 28 of the shaft 26. By the same token, each of the non-rotatable refiner discs is axially slidable on the pins 44.
Each of the refiner discs 30 and 36 and each of a pair of end discs 46 and 48 respectively mounted to the housing parts 12 and 14, comprise refiner bars which accomplish the actual refining operation.
As previously mentioned, the refiner may be loaded with the desired power by axially adjusting the last stationary element, in this case the element 46 or the element 48. This may be accomplished by screw techniques, or by a gear motor or the like and essentially adjust the relative spacing of the housing parts 12 and 14, as indicated by the double-headed arrow 50. As shown in FIG. 1, the splined shaft may be provided with an end cap 52 secured to the distal end of the shaft by way of at least one screw 54 which may be employed to maintain the rotatable refiner disc on the shaft prior to assembly of the left and right-hand sides of the housing parts illustrated in FIG. 1. After assembly, of course, the axial movement of the refiner disc are limited by the fixed refiner disc 46 and 48.
As mentioned above, and stated in slightly different terms, is to essentially match a given size refiner to process the requirements by providing the refiner with a number of refining discs which will accomplish a low intensity treatment so as to increase the strength characteristics of the pulp and reduce the amount of specific energy required for the refining process. This may be readily accomplished in practicing the present invention with structure of the type illustrated in FIG. 1 in which the housing parts 12 and 14 are separated from one another and the desired number of refiner discs 30 and 36 are mounted, respectively, on the splined shaft 26,28 and on the support pins 44.
As mentioned above, the torque transmitting section of the shaft may comprise various cross-sectional shapes. - Examples of these are illustrated in FIGS. 4-6.
Referring to FIG. 4, a refiner disk 36A includes a square central aperture 32A for receiving a square torque transmitting section 26A of the shaft.
In FIG. 5, a disk 36B includes a central aperture 32B in the form of a triangle for receiving a triangular section 26B of a shaft. In FIG. 6, the disk 36C includes a hexagonal central opening 32C for receiving a hexagonal section 26C of a shaft.
The above torque transmitting constructions, of course, are not the only constructions which may be employed in practicing the invention.
By the same token, the support pins 44 of FIGS. 1-3 may be replaced by other structures. Examples of such structures are illustrated in FIGS. 7-9.
Referring to FIG. 7, a disk 36D includes a projection having an arcuate groove 42D for slidingly receiving a complemental arcuate projection 44D which is secured to the refiner housing.
In a similar, but somewhat reverse manner, FIG. 8 illustrates a disk 36E carrying a trapezoidal projection 42E to be slidingly received in a complemental groove 44E extending from the wall of the refiner housing.
In somewhat the same manner as in FIGS. 1-3, FIG. 9 illustrates the use of an oval support pin 44F to be slidingly received in an oval aperture 42F provided on an extension of the refiner disk 36F.
Although we have described our invention by reference to particular illustrative embodiments thereof, many other changes and modifications of the invention may Become apparent to those skilled in the art without departing from the spirit and scope of the invention. We therefore intend to include 'within the patent warranted hereon all such changes and modifications as may reasonably and properly be included within the scope of our contribution to the art.