US3066731A - Papermaking machine - Google Patents

Description

Dec. 4, 1962 c. A. LEE

PAPERMAKING MACHINE 2 Sheets-Sheet 1 Filed Sept. 21, 1959 Q NW Dec. 4, 1962 c. A. LEE

PAPERMAKING MACHINE 2 Sheets-Sheet 2 Filed Sept. 21, 1959 United States Patent ()fiice ZifidhJBl Patented Dec. 4%, 1962 3,066,731 PAPERMAKING MAtlHlNE Charles A. Lee, Knoxville, Tenn, assignor to Kimberly- Clark Corporation, Neenah, Wis, a corporation of Delaware Filed Sept. 21, 1959, Ser. No. 841,219 3 Claims. (1. 162-289) My invention relates to papermaking machines and more particularly to such machines of the Fourdrinier type.

A Fourdrinier papermarking machine comprises, in general, a plurality of rolls having a wire travelling around the rolls at high speed. An aqueous suspension of fiber, commonly designated as stock, is supplied on to the Fourdrinier wire through which water is drained so as to form a wet paper web. Various devices, such as table rolls and suction boxes beneath the wire, are commonly utilized for increasing the rate at which water is Withdrawn from the web.

Prior to the development of the pressure forming type of papermaking machine, it was the general practice to form the mat of fibers of which the paper web is composed by flowing or spouting on to the Wire a layer of stock. The water drained from the stock through the Wire sufficiently so that, at the end of a horizontal pass of the wire, the formed web constituted a coherent sheet capable of being couched off the wire.

Subsequently faster operating machines were developed of the pressure forming type. In this type, the stock, while contained within an enclosed flow conduit, is applied to a restricted area of the wire as a relatively high energy flowing stream. The stream is under substantial hydraulic pressure, and the pressure energy component of the stream of stock applied to the wire is usually quite large in relation to the velocity energy component. A large portion of the water in the stock mixture is therefore forced through the wire in the Web forming region at a relatively high rate. The web forming region in a machine of this type is quite commonly at the periphery of a so called breast roll, which, together with a couch roll and idler and table rolls, support the Fourdrinier Wll3.

As is discosed in my prior Patent No. 2,756,649, issued July 31, 1956, on Flow Control Apparatus for a Fourdrinier type paper machine, the breast roll beneath the area on the Fourdrinier wire on which the stock is deposited may be or an open type having a plurality of general radially extending bent vanes supported by a plurality of radial rings, with a helical who being disposed over the vanes to directly support the Fourdrinier wire running on the breast roll. The breast roll is made open in this manner so that water from the stock as it is deposited under pressure on the wire may flow directly through the wire and through the breast roll, helping to rapidly withdraw the water from the paper web and allow faster operation of the machine. In some cases, open breast rolls of this type utilize vacuum chambers therein for the purpose of increasing the water drainage from the web at the time the stock is deposited on the wire, such an open vacuum breast roll also being illustrated in my prior Patent 2,75 6,649.

It has been found with such breast rolls that after periods of usage there occurs an accumulation of stock fibers within the vanes and between the rings supporting the vanes which causes poor and uneven formation of the paper Web. Due to the fact that the vanes have been bent and due to the fact that access is not available from the ends of the rolls, it has generally been very difficult to clean the breast rolls of such stock fiber accumulation.

It is therefore an object of the present invention to proiii) vide an improved breast roll so constructed that it is not subject to such accumulation of stock fiber; and, in this connection, it is an object to provide a breast roll which has an internal cavity within the vanes that is deeper than such cavities in prior rolls, allowing a freer water flow and more effective drainage from the roll.

It is also an object of the invention to provide an improved breast roll that is more easily cleaned than prior rolls and more particularly to provide a roll that has straight vanes allowing water to be jetted into the cavity through the vanes. It is also an object to render the cavity within the vanes accessible to streams of water from the ends of the rolls, such as through aligned openings provided in the roll ends and in the radial rings.

The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above stated objects, and such other objects, as will be apparent from the following description of a preferred embodiment of the invention, illustrated with reference to the accompanying drawings, wherein:

FIG. 1 is a longitudinal sectional view of a breast roll embodying the principles of the invention;

FIG. 2 is a partial sectional view of the breast roll on an enlarged scale taken on line 2-2 of FIG. 1;

FIG. 3 is a partial longitudinal sectional View of the breast roll also on an enlarged scale; and

FIG. 4 is partial longitudinal sectional view of the breast roll on a still greater enlarged scale.

Referring now to the drawings, the illustrated breast roll may be seen to comprise a pair of heads 10 each having a shaft 11 fixed therein. A cylindrical shell 12 is disposed over the heads it and fits against a shoulder 13 formed on each of the heads iii. The shell 12 is welded to the heads it by means of annular welds 14.

A plurality of support rings 15 are disposed on the shell 12. Each of the support rings 15 comprises a cylindrical base portion l6 and a radially extending ring portion 17 having a plurality of equally spaced openings 3.8 therethrough. The cylindrical base portions 16 fit on the shell 12 and are welded together as at 19.

An end ring 29 is fixed on each end of the roll. Each end ring comprises a cylindrical shell portion 21 and is provided with a plurality of equally spaced openings 22 therethrough. The openings 18 of the support rings 15 are in alignment, and the end rings 2% have the same number of openings 22 which are in alignment with the openings 18.

A so called water fiinger annular part 23 is fixed on each shaft 11. A cover plate 24 extends between the cylindrical portion 21 of each of the end rings 20 and the adjacent part 23. Each cover plate is detachably held in place by means of screws 25.

A plurality of vanes 26 extend longitudinally of the roll and are disposed in slots 27 provided in the support rings 15. A wire 23 is helically wound around the roll and is disposed in slots 2% provided in the outer ends of the vanes 26. As wiil be observed from FIG. 2 in particular, the vanes 26 in cross section are fiat; and, in the particular illustrated embodiment, they extend at 45 degrees with respect to a radial line 3t passing through the center of the breast roll. The illustrated breast roll rotates in the direction shown by the arrow 31, and, as will be observed, the vanes 2e are canted from the support rings 15 in the direction of rotation.

In a particular embodiment of the improved breast roll, the outer diameter of the base portions 16, constituting in efiect the outer diameter of an internal core of the breast roll, was 16% inches. The outer diameter of the breast roll as a whole was 25 inches, so that the cavity of the breast roll, extending from the outer cylindrical surfaces of the base portions 16 to the outer edges of the wire 28, was substantially 4- /2 inches deep.

Other breast rolls built according to the teachings of the invention respectively had outer diameters of 24 and 36 inches and outer diameters of the base portions of 16% and 27% inches. The depths of the cavities of these breast rolls were therefore respectively 3% and 4- /8 inches. roll would, on the other hand, be less than 1% inches. The cavity depth has thus been increased by at least twice in the improved breast roll of the invention.

in operation, the breast roll is mounted in a Fourdrinier machine; and it, together with other rolls, support an endless Fourdrinier wire. The wire has a horizontal pass between the breast roll and another of the rolls, and a slurry of paper stock is deposited under pres sure on the horizontal pass of the wire, just as it leaves the top of the breast roll, such as by mechanism shown in my prior Patent 2,756,649 previously referred to.

Due to the pressure applied to the slurry, some of the water from the slurry flows between the convolutions of the wire 2% and between the vanes 26 and between the support rings at the point of deposit of the slurry on to the wire. The breast roll, being open, helps to remove some of the water from the paper web being formed on the wire and hastens its formation. The breast roll in its rotation has its periphery move beyond and underneath the horizontal pass of the wire and within the loop of the wire, and the water that has been forced within the roll at the point of deposit of the slurry on the wire is thrown out by centrifugal force below the horizontal wire pass and ultimately reaches a white water pond beneath the machine. The inclination of the vanes 26 at the angle of degrees with respect to radial assures that the water that flows through the breast roll is not immediately thrown out back on to the web being formed on the wire, but throw out is rather delayed and most of the water is directed by the breast roll horizontally and away from the horizontal pass of the Fourdrinier wire. The canted vanes 26 simply amount to resistance elements to restrict the white water throw out, imposing a drag surface along which flow of water is impeded and preventing the water from being thrown out of the breast roll by centrifugal force immediately. It is to be noted that the blades 26 are inclined in the direction of rotation of the roll indicated by the arrow 31 in order to achieve this result and furthermore that the blades 26 are straight rather than being bent so as to provide an openness of the breast roll periphery that would otherwise not be present to allow the white water from the stock slurry to enter the roll easier.

Insofar as the angle of 45 degrees for the blades is concerned, obviously, if the vanes were perfectly radial, they would offer no drag force to the water being thrown out; and, on the other hand, if they were circumferential, they would retard the throw out completely; and the angle is therefore chosen so as to be approximately midway between these two limiting positions.

Paper stock fibers tend to accumulate within the roll inside of the vanes 26, and they restrict the free air ventilation. between the vanes. As water plunges through the vanes, the air within the cavity must be driven out; and, if paper fibers partially fill the cavity, the air is compressed and prevents sufiicient drainage and flow of water through the roll to provide proper sheet formation on the surface of the Fourdrinier wire. The illustrated roll provides a cylindrical cavity extending between the outer diameter of the wire 23 and the outer diameter of the base portions 16 which, as previously described, is substantially deeper than the cavities in prior conventional breast rolls. The illustrated breast roll thus has an openness of construction allowing greater flow of water and air through the breast roll, and there is less likelihood that paper fibers will accumulate within the cavity. The fact that the blades 26 are flat, rather than being bent, also contributes The corresponding cavity of a conventional breast to this openness of construction and the increased facility of the breast roll to pass water and air therethrough. The illustrated breast roll, in tending to prevent such fiber accumulations within it, thus can be expected to provide better paper formation than prior breast rolls in which such accumulations tend to occur. Due to the increased openness of the breast roll and greater facility of passing water therethrough, it also can be expected to allow faster paper web formation.

The illustrated breast roll due to its construction may be much easier cleaned of any fibers remaining in the breast roll as compared to prior rolls. In view of the fact that the vanes 26 are straight, streams of water may be jetted directly into the cavity of the breast roll between the vanes for flushing fibers out of the internal cavity. Also the plates may be removed from the ends of the roll, and streams of water may be directed through the aligned openings 22 and 13 for flushing out the roll.

The improved breast roll advantageously has an increased cavity depth so as to provide increased ventilation and greater capacity for the roll to receive water for better and increased speed of paper web formation and less likelihood of fiber accumulation. The vanes 26 are straight and may thus be economically cut from fiat metal strips. The aligned holes 18 and 22, as well as the straight vanes 26, permit streams of water to be jetted into the internal cavity of the roll for cleaning purposes.

I wish it to be understood that the invention is not to be limited to the specific constructions and arrangements shown and described, except only insofar as the claims may be so limited, as it will be understood to those skilled in the art that changes may be made without departing from the principles of the invention.

What is claimed is:

1. An open type breast roll for a paperrnaking machine adapted to support a Fourdrinier wire and to receive water draining from paper stock discharged onto the wire and roll and to retain some of the water for a portion of a revolution and comprising means forming an inner core, a pair of end rings and a plurality of intermediate support rings fixed with respect to said core, and means providing an external perforated surface for the breast roll supported by said support rings and providing a peripheral cavity about said core and between said core and said external perforated surface, said last named means including a plurality of vanes extending longitudinally of the roll and canted in the direction of rotation of the roll, the improvement comprising said end rings and said support rings having a plurality of aligned openings therethrough so that said cavity may be flushed out by directing fluid through said aligned openings.

2. An open type breast roll for a papermaking machine adapted to support a Fourdrinier wire and to receive water draining from paper stock discharged onto the wire and roll and to retain some of the water for a portion of a revolution and comprising means forming an inner core, a pair of end rings fixed with respect to said core and providing cylindrical zones of an exterior surface of the roll, a plurality of intermediate support rings fixed with respect to said core, a plurality of vanes supported by said support rings to extend longitudinally of the roll and have a cant in the direction of rotation of the roll, and a wire helically wound about said vanes, said vanes and wire providing an external cylindrical perforated roll surface completing the breast roll exterior surface between said zones and defining a cavity about said core and between said surface and the core, the improvement comprising said end rings and said support rings having a plurality of aligned openings therethrough and said vanes being formed of fiat strips for permitting a flushing out of said cavity by directing flushing fluid inwardly of said surface or through said aligned openings.

3. An open type breast roll for a papermaking machine adapted to support a Fourdrinier wire and to receive water draining from paper stock discharged onto the Wire and roll and to retain some of the water for a portion of a revolution and comprising means forming an inner core, a pair of end rings and a plurality of intermediate support rings fixed with respect to said core, and means providing an external perforated surface for the breast roll supported by said support rings and providing a peripheral cavity about said core and between said core and said external perforated surface, said last named means including a plurality of vanes extending longitudinally of the roll and canted in the direction of rotation of the roll, the improvement comprising said end rings and said support rings having a plurality of aligned openings therethrough so that said cavity may be flushed 15 out by directing fluid through said aligned openings, and said end rings and said support rings having such dimensions in the radial direction that the depth of said cavity is more than three inches.

References Cited in the file of this patent UNITED STATES PATENTS 811,660 Parker Feb. 6, 1906 1,666,472 Seybold et al Apr. 17, 1928 2,520,327 Nilson Aug. 29, 1950 2,756,649 Lee July 31, 1956 2,756,650 Lee July 31, 1956 2,888,074 Hornbostel May 26, 1959 FOREIGN PATENTS 126,849 Germany Jan. 4, 1902 339,490 Switzerland Aug. 31, 1959 518.708 Canada Nov. 22. 1955

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