US2399988A - Method fob refining paper stock - Google Patents

Description

y 7, 1946. E. cowLEs 2399,988

METHODS FOR REFINING PAPER STOCK Filed Dec. 5, 1942 3 Sheets-Sheet 1 INVENTOR ATTORNEYS May 7, 1946. E. cowLEs METHODS FOR REFINING PAPER STOCK Filed D80. 5, 1942 3 Sheets-Sheet 2 INVENTOR r 4 ATTORNEYS E. COWLES May 7, 1946.

3 Sheets-Sheet 3 Filed Dec. 5, 1942 llllllll l i m n HEW T INVENTOR I {I i I '1 Patented May I, 1946 METHOD FOR REFINING PAPER STOCK Edwin Cowles, Cayuga, N. Y., assignor to The Cowles Company, Princeton, N. J., a corporation of New Jersey Application December 5, 1942, Serial No. 467,930

3 Claims. (Cl. 92-26) This invention relates to methods for refining paper stock, and particularly for performing those types of refining action including cutting, hydrating and fibrilating which are commonly obtained in beaters or Jordan engines or other equipment of similar types.

In the operation of such machines it is common to work the fibers between a fixed member such as the bed plate of'a beater or the hollow cone of a Jordan engine, and a moving member such as the roll of a heater or the plug of a Jordan engine. While both types of machines perform satisfactorily as far as the quality of the work is concerned, it hasbeen found that. both typ s are highly inefficient, i. e. the power consumption is grossly excessive for the amount of work performed on the stock.

My observation has been that this inefficiency is caused by the fact that large amounts of power are consumed uselessly in circulating the stock or in overcoming friction in the machineparts themselves rather than in the performance of useful work on the fibers. This result occurs be- 7 cause in all such machines the presence or absence of fibers on the opposed parts at the point of working engagement is left entirely to chance, and even under most favorable conditions the parts are only sparsely coated with fibers at the point of working engagement.

It is an object of the present invention to improve the inefficient action of such machines by. insuring that the fibers are continuously fed to and distributed over the opposed parts, in order that an increased proportion of work expended may be applied to the fibers themselves.

3 Other objects and advantages of the invention Figure 8 is a top plan view of the same. Figure 9 is a side elevation of the interior of the casing collar.

Figures 10, 11, 12 and 13 are schematic diagrams illustrating the principles of the invention.

the body of stock, and (2) the conditions should be such as to cause the fibers which are picked up by the moving member to be retained thereon while said moving member is advancing to working engagement with a fixed member.

In order to satisfy these conditions I propose to advance a moving member having an edge through a body of paper stock in such manner that the frictional forces exerted on fibers which staple over said edge will be substantially equal, thus creating conditions favorable for the retention of fibers on said edge. For example, in its simplest form the method of my invention may be practiced by advancing a relatively thin blade a edgewise through a body.of stock as shown in the diagram Figure 10 in a manner such that the direction of movement of the side surfaces of the blade is parallel to the direction of movement.

when a blade is advanced in this manner the conditions are favorable for retaining fibers which staple over the advancing edge, for the velocities of stock movement along the blade surfaces, and hence the frictional forces exerted on 5 the trailing ends of the fibers will be substantially equal. After fibers are picked up in this manner, further advancing movement brings said member into working engagement with a fixed member b, so that the fibers are worked therebetween.

The problem of satisfying these conditions in a practicaL- commercial machine is complicated, however, by the necessity of providing adequate structural strength and rigidity in the moving member to resist deflection when said member carrying the fibers picked up is brought into working engagement with the fixed member, for if substantial deflection occurs, the conditions are not favorable for working the fibers.

In the form previously described, the blade may i ure 4 is a section on the line 4-4 of Figure 1. 5 be utilized successfully as a moving member if the Figure 5 is a side elevation of the upper fixed Figure 6 is a bottom plan view of the same. Figure 7 is a side elevation of the lower fixed 118.

blade is relatively short and is thickened transversely as indicated in the blade a in the diagram Figure 11, but obviously the extent to which such thickening may be carried is limited due to the shm'tness of the fibers themselves, and except under unusual conditions a blade having a thickness exceeding one eighth of an inch loses its effectiveness.

If additional thickening is required to provide structural strength and rigidity, it may be provided, as indicated in the diagram Figure 12, in a relatively heavy member a having an advancing edge formed by the intersection of two converging surfaces. Here, if the member is advanced in the direction indicated by the arrow, the conditions for Picking up and retaining fibers on the edge are good, for the velocities of stock movement relative to the inclined surfaces will be substantially equal, and the frictional forces acting on the trailing ends of the fibers will be substantially equal, but the thickening of the member prevents the fibers which have been picked up from being brought into working engagement with the fixed member b'.

Therefore, in the preferred embodiment of the present invention, as indicated in the diagram Figure 13, in order to provide the requisite structural strength or rigidity, I provide a moving member (I having an advancing edge formed by the intersection of two surfaces converging at an angle, preferably at an acute angle, and in order to provide proper working engagement between said moving member and a fixed member 22 I advance the moving member through the paper stock in a direction parallel to one of said intersecting surfaces. It follows, therefore, that the other intersecting surface is inclined to the direction of movement of said member. It wi1l.be apparent, therefore, that if the moving member were to be advanced in this manner through a stationary body of stock, the velocity of stock movement relative to the surface which is parallel to the direction of movement of the member would be greater than the velocity of stock movement relative to the surface which is inclined thereto. This differential in velocity, however, would work against the retention of fibers on said edge, for the frictional forces tending to pull fibers oil the advancing edge would be greater along the parallel surface where the velocity of stock movement is greater.

Accordingly, in order to restore the balance, and to provide conditions most favorable for the retention of fibers on the advancing edge I cause the body of stock to flow across the path of movement of the advancing edge in the direction indicated by the arrow, so as to increase the velocity of stock movement along the inclined surface, thereby tending to produce substantially equal velocities along the two intersecting surfaces so as to equalize the frictional forces acting on the The desired flow of the body of stock across the path of movement of the advancing edge may be induced in a variety of ways, as for example, by means described in detail hereinafter. It is also possible to formthe trailing portion of each of a series of said moving members in the form of a vane which in itself induces a flow of stock across the path of movement of the next succeeding advancing edge.

The rate of flow of the body of stock across the path of movement of the advancing edge may be adjusted with relation to the design or conformation of said moving member in order to secure the desired condition of substantially equal velocities of stock movement along th intersecting surfaces thereof. In general, the smaller the angle between said intersecting surfaces, the slower is angle is small the trailing portion of the movin member may easily be caused to provide the necessary flow. In other cases where the angle is greater, as where it is necessary to provide a more rugged construction, or for other reasons, a higher rate of flow of the body of stock will be required, and in such cases other or additional means may be required to provide the required flow.

The foregoing is illustrated in Figure 4, in which I is the moving member having an edge 2 formed by the intersection of the converging surfaces z and u. 3 is the fixed member. The moving member is advanced in the direction indicated by the arrow A, which, as shown, is in a direction parallel to the surface 11. In order to provide substantially equal velocities of stock movement along the surfaces :1: and 1/ as previously explained, the stock is caused to flow across the path of movement of the edge in the direction indicated by the arrows B. The means for inducing such flow are described hereinafter.

As shown in the drawings, the surfaces :1: and y intersect at an angle of approximately 45, providing a V-shaped edge over which fibers will staple readily, but at the same time providing a member of considerable strength and rigidity. The angle of intersection may be greater or less than that shown, however, although preferably the angle should not exceed 90. It will be understood, moreover, that the edge 2 may be sharpened to a knife edge or may be a dull or rounded edge depending on the nature of the refining action desired, If it is desired that a cutting action should predominate, a sharpened edg'e should be used, but if it is desired that a hydrating or fibrilating action should predominate, a dull edge should be used.

In the machine for carrying out this method, a plurality of such moving members are carried on a ring 5 and two of such rings may be mounted on a hub 6 keyed to shaft 1 as shown in Figure 1, in such manner that the edges 2 are arranged substantially radially thereof. This assembly will be referred to hereinafter as an impeller wheel.

The fixed members I are carried on rings 8 and are also arranged substantially radially, although they may be somewhat inclined to true radii, as shown in Figures 6 and 7, in order to induce a more effective circulation and in order to permit a shearing action between the fixed members and the edges 2, which is particularly useful when it is desired to cut the fibers.

The shaft 1 extends through the upper casing member 0 having a suitable gland packing I0 therein, and the impeller wheel rotates between the member 9 and a lower casing member 9', the

said members being spaced by a collar II. The rings 8 are supported loosely on rubber diaphragms l2 and I3, which said diaphragms are secured at their edges to the upper and lower casing members by means of rings ll, l5, l6 and I1. Preferably the rings l4 and [6 are provided with spaced lugs l8 adapted to engage the members 3 to prevent the rings 8 from rotating. Said rings are free to move vertically, however, and such vertical movement is controlled by the diaphragms I2 and i3. Thus, the upper and lower casing members are provided with annular chambers l8 and 20 through which fluid pressure may be applied to the diaphragms in order to move the rings vertically. In this manner the working pressure between the fixed members 3 and the moving members I may be controlled as dethe required flow of stock, and in cases where the sired.

The lower casing member is provided with an intake passage 2 I, and the ring I I is provided with a port 22 for the discharge of treated material.

In the preferred embodiment illustrated, the desired flow of stock across the path of the moving members is secured as follows. It will be noted that the spaces between successive moving members I provide a plurality of passages 25 which terminate in openings 26 in the periphery of the wheel. The inflowing stock, following the path of the arrows C, moves into the spaces 21 between successive fixed members 3, then moves across the path of the moving members I into the passage 25, and then is discharged radially through the openings 26 under the influence of centrifugal force as the wheel is rotated. As the stock moves across the path of the advancing moving members I, a layer of fibers is picked up by the edge 2, and since the flow of stock across the path of the moving members which is induced by the radial discharge of stock is such as to substantially equalize the velocities of stock movement relative to the intersecting surfaces z and 1/, the fibers which are picked up by the edge tend to be retained thereon, so that when the advancing moving member reaches the next fixed member, the fibers which have been picked up are worked between said members as previously explained.

In the preferred embodiment illustrated pro-- vision is made for recycling the material discharged from the openings 28 so that it may be immediately and repeatedly retreated before being discharged from the machine. Thus, the collar II is provided with two spaced grooves 30 and 3| separated by a rib 32, which said rib splits the streams of stock discharged from the openings 26 so that part of the stock enters the groove 30 and the remainder enters the groove 3 In each case the stock moves in the direction of the arrow D, returning to the spaces 21 and again moving across the path of the moving members into the passages 25. In order to retard circulation of the stock lengthwise of the grooves Ill and 3|, the said rooves may be provided with vanes 33 which intercept the stock discharged from the passages 25 and direct the flow back toward the spaces 21, from which the stock again moves across the path of the moving member It will be understood that the invention may be variously modified and embodied within the scope of the subjoined claims.

I claim as my invention:

1. The method of refining paper stock which comprises advancing a member having an edge through a body of stock in a direction such that the velocities of stock movement relative to the surfaces of said member lying adjacent said edge on either side thereof are substantially equal, said edge being free of working engagement with any opposed member during said advancing movement so that individual fibers contained in said stock are picked up and retained by said edge, and advancing said member into working engagement with a fixed member so that the fibers carried by said edge are worked between said members.

2. The method of refining paper stock which comprises picking up fibers on the advancing edge of a moving member, said edge being formed by the intersection of two converging surfaces, by moving said member through a body of stock in a direction parallel to one of said surfaces, moving said stock across the path of movement of said member in a direction and at a velocity sufiicient to produce resultant velocities of stock movement relative to the two intersecting surfaces which are substantially equal, and movin said member into working engagement with a fixed member so that the fibers picked up by said edge are worked therebetween.

3. The method of refining paper stock which comprises picking up fibers on the advancing edge of a moving member, said edge being formed by the intersection of two converging surfaces, by moving said member through a body of stock in a direction parallel to one of said surfaces, the other of said intersecting surfaces being inclined thereto, moving said stock across the path of movement of said edge in a direction and at a velocity sufllcient to increase the velocity of stock movement relative to said inclined surface to a point substantially equal to the velocity of stock movement relative to said parallel surface, and advancing said member into working engagement with a, fixed member so that the fibers picked up by said edge are worked therebetween.

EDWIN COWLES.

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