US2180080A

US2180080A - Appabatus fob befdhng papeb stock

Info

Publication number: US2180080A
Authority: US
Publication date: 1939-11-14
Anticipated expiration: 1956-11-14

Description

APPARATUS FOR REFINiNG PAPER STOCK Filed July 5, 1955 a Sheets-Sheet 1 INVENTOR 422: Qua.

Nov. 1 1939. E. COMES 2.1801180 APPARATUS FOR REFINING PAPER STOCK Filed July 5, 1955 3 Sheets-Sheet 2 a Q v I'IHIIIH Nov. 14, 1939. E. COWLES 2,180,080

APPARATUS FOR REFINING PAPER STOCK Filed July 5, 1935 3 Sheets-Sheet 3 28 INV TOR c Patented Nov. 14, 1939 APPARATUS FOR narmmc PAPER STOCK Edwin Cowles, Hopewell, N. J., .assignor to The Cowles Company, Princeton, N. J., a corporation of New Jersey Application July 5, 1935, Serial No. 29,842

10 Claims.

This invention relates to apparatus for refining paper stock and constitutes an improvement in apparatus of the type disclosed in my previous Patent No. 2,033,123, dated March 10, 1936.

In the preparation of paper stock for use in paper making machines, it is necessary to completely defiber the fibrous material, and also to subject the fibers to a grinding, crushing action which improves the quality of the stock. If the stock is dirty, or if, as in the case of stock prepared fromwaste paper, it contains large quantities of trash and dirt, it is necessary to separate the trash and dirt from the fibrous material. In the usual processes for preparing paper stock, these operations are usually performed separately in separate pieces of apparatus. of the present invention to provide an apparatus which will perform, in whole or in part, and either singly or in combination, the functions of several pieces of apparatus which have been used for these purposes heretofore. Thus it is an object of the invention to provide an apparatus which will perform a defibering operation, or a grinding and crushing operation, or a separating operation, or various combinations of these operations depending upon the material .beingtreated and the nature of the system or process in which the apparatus is incorporated; It is a further object of the invention to incorporate in the apparatus certain features adapted particularly for the treatment of waste paper stock which enable the apparatus to operate efiiciently for long periods of time without becoming clogged, due to accumulations of trash or undefibered material.

Other objects and advantages of the invention will appear hereinafter.

A preferred embodiment of the invention selected for purposes of illustration is shown in the accompanying drawings, in which,

Figure 1 is a front elevation of the apparatus, partly in section in order to better illustrate the interior thereof.

Figure 2 is an end elevation.

Figure 3 is a section on the line 3-3 of Figure 1.

Figure 4 is an enlarged detailed sectional view on the line 4-4 of .Figure 5 illustrating one of the impeller vanes and the attached scrapers.

Figure 5 is an enlargeddetailed sectional view on the line 5-5 of Figure 4, and

Figure 6 is an enlarged detailed sectional view on the line 66 of Figure 5. n

Referring to the drawings, the apparatus comprises a casing having opposed end plates I and It is an object I 2 which are spaced by'an annular ring 3 located therebetween and forming a. chamber 4 for purposes hereinafter described. The end.plate I is provided with an opening 5 constitutingan inlet opening to the casing and the chamber 4, and 5 the end plate 2 is provided with a bearing member 6 supporting a shaft I carrying an impeller 8 which rotates within the chamber 4. The plate I is also provided with an outlet opening 9 and the end plate 2 is provided with a similar outlet 10 opening III, the said openings being connected with similar outlet conduits II.

The material to be fed to the apparatus is supplied through the conduit I2, then through a rubber hose connection I3, and through the con- 15 duit I4 to the inlet opening 5. Preferably the end plates I and 2 are carried on a framework comprising a pair of I-beams I5 and I6, the said end plate I being provided with shoes I1 which rest on the upper flanges of the I-beams and may be 2 conveniently secured thereto byclamps I8. The ring 3 is also provided with shoes resting on the I-beams, while theend plate 2 is carried by a support I'I, secured to the bearing member 6 and bolted to the I-beams. The end plates I and 2 5 and the annular ring 3 therebetween may be' conveniently secured together by bolts I9.

By constructing and supporting the apparatus in this manner, convenient access to the interior of the apparatus for cleaning and repairs may 30 be had by releasing the couplings 20 and 2|, removing the hose connection I3, and then releasing the coupling 22 and the bolts I9 and clamps I8. Thus the end plate I may be slid out of place with its shoes II still resting on the I-beams, 35 thus giving access to the interior'of the casing. Similarly thering'3 may be slid out of place while still supported on the I-beams. If desired, the impeller 8 may be removed from the shaft I by removing the nut 23.

The impeller may be driven in any suitable manner as by a pulley or motor connected to the shaft I.

The end plate I is provided with an annular 45 chamber or trough 24 andthe end plate 2 is provided with a similar annular chamber or ratus through outlet openings 9 and 10 without passing through the

screens

26 and 21.

The said screens, which are in the form of annular disks, are supported from behind by the grids or

frames

28 and 29 having large openings 30 therein so as not to interfere with the flow of material through the screens. The screens 26 and 2'! are held rigidly in place, being clamped at their outer peripheries between the annular ring 3 and the supporting

frames

28 and 29, which in turn are clamped between the end plates I and 2. The inner peripheries of the screens are fastened between the supporting

frames

28 and 29 and screen retaining plates 3| and 32 by screws 33.

Any suitable type of screen may be employed, but I prefer to use sheet metal plates having perforations 34 punched therein, the said perforations preferably being arranged in radial lines converging toward the axis of the impeller, with the perforations of adjacent radial lines staggered or off-set as illustrated in Figure 5 so that perforations equidistant from the axis are spaced fairly widely. In treating certain classes of material, as for example, waste paper which contains large quantities of strings and stringy material, it has been found that there is a tendency for such stringy material to lace between perforations which are equidistant from the axis unless said perforations are spaced fairly widely. On the other hand, there is almost no tendency to lace between perforations which are not equidistant from the axis. With the described arrangement of perforations on radial lines which are offset, it is possible to use a larger number of perforations in a given area, thus increasing the capacity of the machine, while at the same time avoiding lacing.

The sizes of the perforations and the spacing between perforations must be varied depending upon the nature of the material treated and the consistency thereof in order to secure best results, but certain relationships have been found to be important. Thus the distance between centers of perforations equidistant from the axis should not be less than two times the diameter of the perforations if lacing is to be avoided, and preferably, near the outer periphery of the screens, this distance should be not less than three times. Furthermore the thickness of the screen plate should not exceed the diameter of the perforations. In the treatment of waste paper, I have found that'perforations having a diameter of A,", spaced radially apart between centers, with perforations equidistant from the axis spaced approximately apart between centers at the outerperiphery of the screen give satis factory results when treating waste paper stock at a consistency of 2% to 4%. In this case the thickness of the screen plate should be less than The impeller 8 comprises a plurality of radial vanes or paddles 35 which are reinforced by the web members 36. erably rotated at a rate suflicient to secure lineal velocities in the region of the screens in excess of 2000 feet per minute, serve to spin the material within the chamber 4 formed by the

screens

26 and 21 and the annular ring 3. In treating certain classes of materials, the rotation of the vanes themselves in close proximity to the screens is sufficient to clear the screen perforations of fibrous material and also to produce a rubbing or crushing effect on the fibers between the edges of the vanes and the surface These vanes, which are pref-' vanes of the impeller.

of the screens, which rubbing serves to defiber some of the undefibered material which may be supplied to the machine, and also serves to grind and crush the fibers between the edges of the blades and the surface of the screen. In treating some classes of materials, however, it has been found advisable to provide means which bear against the surfaces of the screens in order to increase the effectiveness of the action. In the embodiment illustrated, the said means are movably mounted on the impeller vanes and comprise scrapers 40 which are hinged to the vanes of the impeller, thescrapcrs being secured to hinge plates 4| which are pivotally connected to plates 42 by the hinge pin 43. The plates 42 are bolted to the impeller vanes.

It is desirable that means be provided to prevent the scrapers from being thrown upwardly away from the screen, and in the preferred embodiment stop plates 44, secured to plates 4| and perpendicular thereto, are provided which abut the plates 42 and prevent the scrapers from lifting more than a slight distance away from the screen. Inasmuch as the foot of the scraper which bears against the screen wears fairly rapidly from abrasion, the front face 45 of the scraper is preferably inclined backwardly so that as the scrapers move through the material a sharp leading edge is maintained. It has also been found advisable to cut away the under side of the scraper as indicated at 46 so that as wear occurs, the area of the scraper in contact with the screen does not increase substantially. It is also desirable to provide a stop 41 to prevent the scrapers from swinging too far in the direction of the screen as excessive wear occurs.

It will be observed that since the leading edge of each scraper is parallel to the radial vane of the impeller to which it is secured, but is ofiset therefrom, the edge of the scraper does not form a radial line. Consequently, in moving across the radial lines of perforations 34, the edge crosses the perforations lying in any given radial linesuccessively rather than simultaneously and also produces a shearing action as it crosses each perforation. It will also be observed that while the scrapers are hinged to the impeller vane and are permitted slight movement toward and away from the screen, they are rigid and non-yielding in the direction of travel of the impeller vanes so that the impact against'fibers which may be lodged in the screen perforations is non-yielding.

Inasmuch as only substantially completely deflbered material can pass through the relatively small perforations in the screens, it will be apparent that if the material being treated contains large quantities of trash or undefibered material, the impeller chamber would soon become clogged unless an outlet is provided. Consequently an outlet conduit 49 is provided in the annular ring 3 through which material may be removed from the impeller chamber without passing through the screens. The rate of flow through the outlet conduit 49 may be controlled as desired by a valve (not shown).

In treating certain classes of materials. as for example, waste paper, in which considerable quantities of strings and stringy material are sometimes encountered, it has been found that such stringy material tends to form snarls in the impeller chamber in the spaces between adjacent These snarls sometimes become too large to be ejected through the outlet opening 49, and accordingly I have provided prongs 50, mounted in the annular ring 3, which a aopso project into the impeller chamber. The end edges of the impeller vanes are provided with notches SI of sufficient size to clear the prongs, the result being either that thesnarls which may form are pulled apart by the prongs cooperating with the notches 5|, or else snarls are prevented from forming to any objectionablesize.

Still another difflculty which is encountered in treating'waste paper is the tendency for trash to accumulate and clog the outlet opening 48. In order to avoid this difficulty resilient members 52 are mounted on the impeller vanes in pomtion to wipe the outlet opening so as to prevent such accumulations.

' Another difliculty which has been encountered in treating such material is the tendency of stringy materials and rags to wind themselves around the impeller vanes in the area between the screen and the hub of the impeller. In order to go overcome this difliculty, I have provided a roughened surface in the form of a series of radial grooves 53 in the surface of the screen retaining plate 3|, and these grooves serve to abrade such material and prevent troublesome accumulations.

If desired, adjustable cutting plates 54 may be mounted on the vanes and 'adjusted into close proximity to the surface of the screen retaining a plate, thus improving the abrading action.

It has also been found that there is a' tendency for fibrous material to lodge and accumulate on the front face of thehub and spokes of the impeller. In order to overcome this difiiculty I fiatten one side of the inlet opening, thus, in effect, making the opening eccentric to the axis of the 5 impeller. This may be conveniently accomplished by providing a member 55 in the opening and extending into close proximity to the hub and vanes of the impeller. As the impeller rotates, this member tends to dislodge from the hub and vanes any fibrous material which tends to accumulate thereon.

In operation, fibrous material suspended in water is supplied to the machine through the conduit l2 and enters the impeller chamber where it is spun rapidly by the impeller. Defibered material and water tend to pass through the screens, but due to the relatively small size of the perforations in the screens, fibers tend to collect in the perforations in the form of small tufts which are engaged by the scrapers and are cut or mashed by the scrapers, thus clearing the perforations and permitting defibered material to pass through. At the same time a grinding, crushing action is produced on the fibers between the scraper and the screen which has a beneficial action on the fibers. Pronounced defibering action on undefibered material is also obtained. The defibered material and water which pass through the screens are removed through the conduits II, and as previously explained, trash and undefibered material, carrying with it of course some defibered material, is removed through the outlet 49.

Apparatus of the type described has a variety of uses. It may be used in the manner previousfor this purpose, the material may be recycled'if necessary or desirable. Or, by introducing maly described to separate defibered material from terial at low consistency, the apparatus maybe .used solely for defibering. Or the apparatus may be used solely for the separation of trash. Other applications of theapparatus will occur to those skilled in the art. 5

It will be understood that the invention may be variously modified and embodied within the scope of the subjoined claims. v

. I claim as my invention:

1. Apparatus for refining paper stock, comprising, in combination, a casing, a pair of screens in said casing, said screen's lying in parallel spaced planes, said casing having an inlet opening on one side of said screens, and an outlet opening on the opposite side of each screen, and an impeller hav- 15 ing vanes rotatable in the space between said screens on an axis perpendicular to'said screens, said impeller vanes having scrapers mounted thereon bearing laterally against each of said screens.

2. Apparatus for refining paper stock, comprising, in combination, a casing, a screen in said casing, said casing having inlet and outlet openings on opposite sides of said screen, an impeller rotatable within said casing, said impeller having vanes, scrapers hingedly mounted on one edge of said vanes and hearing against said screen, said vanes each having an indentation cut in another edge, and a fixed prong mounted on. said casing and projecting into said indentations as the impeller is rotated.

3. Apparatus for refining paper stock, comprising, in combination, a casing, a screen in said casing, said casing having inlet and outlet openings on opposite sides of said screen, an impeller rotatable within said casing, said inlet opening being flattened on one side to provide an abutment in contactwith and swept by said impeller to engage and dislodge material tending to lodge on said impeller.

4. Apparatus for refining paper stock, comprising, in combination, a casing, a screen in said casing, said casing having inlet and outlet openings on opposite sides of said screen, and an impeller rotatable within said casing, said screen being flat and lying in a plane perpendicular to the axis of said impeller, said screen having perforations arranged in radial lines converging toward the axis of said impeller.

5. Apparatus for refining paper stock, comprising, in combination, a casing, a screen in said casing, said casing having inlet and outlet openings on opposite sides of said screen, and an impeller rotatable within said casing, said screen being flat and lying in a plane perpendicular to the axis of said impeller, said screen having perforations arranged in radial lines converging toward the axis of said impeller, the perforations in adjacent radial lines being staggered radially.

6. Apparatus for refining paper stock, comprising, in combination, a casing, a screen in said casing, said casing having inlet and outlet openings on opposite sides of said screen, and an impeller rotatable within said casing, said screen being flat and lying in a plane perpendicular to 5 the axis 'of said impeller, said screen having perforations arranged in radial lines converging toward the axis of said impeller, the circumferential distance between the centers of perforations ing, in combination, a casing, a screen in said casing, said casing having inlet and outlet openings on opposite sides of said screen, and an impel- 7 ler rotatable within said casing, scrapers mounted on said impeller bearing against said screen, said screen being fiat and lying in a plane perpendicular to the axis 01' said impeller, said screen having perforations arranged in radial lines converging toward the axis 01' said impeller, the

edges of said scrapers being arranged at an angle screen as the inlet opening, an impeller rotatable within said casing. and a resilient member secured to said impeller and adapted to wipe said last named outlet opening as said impeller rotates.

9. Apparatus for refining paper stock, comprising, in combination. a casing, a screen in said casing, said casing having inlet and outlet openings on opposite sides of said screen, scrapers mounted on said impeller and bearing against said screen as the impeller rotates, and plates having roughened surfaces lyingclosely adjacent said impeller in planes perpendicular to the axis thereof. and serving to abrade material tending to lodge on said impeller.

10. Apparatus for refining paper stock, comprising in combination, a casing, a fiat screen in said casing, said casing having an inlet opening on one side oi. said screen and an outlet opening on the opposite side of said screen, and an impeller having vanes rotatable within said casing on an axis perpendicular to said screens, said impeller vanes having scrapers mounted thereon bearing laterally against said screen.

EDWIN COWLES.