US3272692A - Pressure forming apparatus in paper making including a suction cylinder mold - Google Patents

Description

p 3, 1966 M. F. HAYES ETAL PRESSURE FORMING APPARATUS IN PAPER MAKING INCLUDING A SUCTION CYLINDER MOLD 5 Sheets-Sheet. 1

Filed Jan. 20, 1964 INVENTORS Mldrd E Hayes 22 ORNEYS & Robert/VI Hayas Sept. 13, 1966 M. F. HAYES ETAL 3,272,692

PRESSURE FORMING APPARATUS IN PAPER MAKING INCLUDING A SUCTION CYLINDER MOLD Filed Jan. 20, 1964 5 Sheets-Sheet INVENTORS Malian; FT/lqyes & Ruberi M Hayes M16MW 22% TTORNEYzS' p 3, 1966 M. F. HAYES ETAL 3,272,692

PRESSURE FORMING APPARATUS IN PAPER MAKING INCLUDING A SUCTION CYLINDER MOLD Filed Jan. 20, 1964 5 shehs Sheet I5 v H a H 1 I. r H! area/ 0 INVENTORS Mallard f-T Hayes & Raberfi flih ayes 5r (27W,%M M

United States Patent 3,272,692 PRESSURE FORMING APPARATUS IN PAPER MAKING INCLUDING A SUCTIUN CYLIN- DER MOLD Millard F. Hayes and Robert M. Hayes, both of R0. Box 92, Hudson Falls, NY. Filed Jan. 20, 1964, Ser. No. 339,011 Claims. (Cl. 162-4517) This invention relates to paper manufacture, and more particularly to suction rolls for use in such manufacture.

In order to remove water from paper during its manufacture, several different kinds of suction rolls are employed. For instance, in a Fourdrinier apparatus, the wire upon which the sheet of paper is formed is generally transported around a suction couch roll from which the paper is transferred to the felt. The suction supplied by such a roll is operative not only to remove water from the sheet of paper, but also to pull the fibers of the paper sheet together, so that it can be transferred to the felt at high speed.

The present invention is applicable for use in suction rolls employed at various points in paper manufacture, and for example in the suction couch roll of the Fourdrinier apparatus. However, the invention is particularly applicable, and will be described herein, in conjunction with a cylinder mold upon which a sheet of paper is formed from a stock of paper fibers entrained in water. Such a mold conventionally comprises a cylindrical wire mesh called a face and which is supported by a pair of end spiders and a plurality of intermediate spiders which themselves mount arcuately-spaced supporting rods. A winding wire is wound under tension on the rods to form a supporting framework for the wire mesh, which may either be of a single layer or of two different layers of different mesh size. In operation of the cylinder mold, the stock is delivered from outside of the roll at a speed generally corresponding to the peripheral speed of the roll and flows through the face into the inner part of the roll. During its flow through the face, nearly all of the fibers entrained in the stock are held by the outside surface of the face and together form the paper sheet.

In the past most cylinder molds have operated with the roll immersed in a slurry of water carrying fibers entrained therein. This immersion in the slurry, together with the centrifugal forces operating upon the stock during rotation of the roll, interfere with the most efficient and rapid formation of the paper sheet.

To reduce these disadvantages of cylinder molds, it has been proposed that suction be applied internally of the mesh face so as to build up a greater head tending to remove more water from the paper fibers and to allow the sheet to be formed faster. One way in which this has been done in the past is through sealing of the ends of the cylindrical roll and pulling a vacuum by a pipe connected to the end seal of the cylinder roll. With this method, however, it is very difficult to generate any considerable vacuum, since a large portion of the cylinder mold is exposed to atmosphere. Moreover, the cylinder mold still rotates in the white water, or slurry with the disadvantage pointed out above.

Other solutions to the problem of application of a vacuum to cylinder molds employ perforated solid castings in conjunction with mesh faces, for the cylindrical surface of the rolls. Such castings are of course much thicker than the mesh faces and are capable of supporting themselves, so that supporting spiders, rods and winding wires are not required. In one of these prior art vacuum molds, vacuum is applied to three-quarters of the arcuate portion of the mold which is either under water or covered by the wet sheet of paper, and the fourth quadrant, which is exposed to air, is sealed off from the rest of the surface.

3,272,692 Patented Sept. 13, 1966 ice In another mold of this general type, suction boxes are employed to apply vacuum to the inner surface of the quadrant of the casting which is instantaneously approaching the couch roll.

These last two prior art suggestions suffer not only from the disadvantage of having half of the mold under water and thereby subject to turbulence interfering with proper sheet formation, but also from the increased effect of centrifugal force resultant from the thickness of the slugs of water which pass through the holes in the castings. The importance of the latter feature may be appreciated if it is considered that the castings may be conventionally of the order of 1% inch in thickness, with each perforation therethrough of approximately inch diameter. The size of the slugs or solid cylinders of water subject to centrifugal force during rotation of the mold is of course tremendously higher than the size of the droplets passing through a wire mesh face which may be of the order of 5080 mesh.

The present invention avoids the disadvantages of the prior art solutions to the problem of drawing a vacuum on a cylinder roll by retention of the conventional mesh face design and the application of a vacuum to a portion of the periphery of the face through water collectors connected to a central core about which the mounting spiders and face of the cylinder are rotatable.

In particular, the present invention replaces the conventional hollow rotatable shaft upon which the spiders are mounted for rotation therewith by a hollow stationary core upon which the spiders, and hence the face are rotatably mounted. This core has slots extending from its outer surface into its inner chamber, which slots mate with Water collectors having funnel portions which define passages extending from adjacent the inner surface of the portion of the face to which stock is supplied, to the core slots. An air pump is connected to this core chamber to increase the head across the face and thereby increase the speed and otherwise improve the formation of the paper sheet.

The invention will now be more fully described in conjunction with drawings showing a preferred embodiment thereof.

In the drawings:

FIG. 1 is a cross-sectional view of the cylinder mold of the invention;

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a partial sectional view similar to FIG. 1 of a modification of the apparatus of FIGS. 1 and 2; and

FIG. 4 is a diagrammatic view of the water and air connections to the cylinder mold of the preceding figures.

Referring first to FIGS. 1 and 2, a cylinder mold conventionally comprises a wire mesh face 10 Which consists of a mutiplicity of small diameter wires which are spaced close together but which form openings therebetween through which water can pass. The outermost layer or face of the cylinder roll is conventionally of between 50 and mesh (wires per inch), depending upon the type of paper to be made. This face is supported, either directly or with an intermediate coarser mesh, by a winding wire 11 which is wrapped regularly around a number of supporting rods 12. The rods 12 are in turn supported by a pair of end spiders 13 and 14 to which opposite ends of the rods are fixed and a plurality of intermediate spiders 15. The intermediate spiders preferably have semi-circular notches formed in their radially outermost surfaces, to hold the rods against forces tending to push them inwardly.

A common illustrative embodiment of the cylinder roll might be of 36 inch outside diameter with 1087 inch diameter rods 12 supporting an 8 gauge winding wire 11 notched into the supporting rods half their diameter, and

with the spiders 4 /2 inches apart. It might also be desirable to support the face by an inner wire mesh or cloth which is considerably more coarse and might be of the order of 14 mesh, to prevent the face from being forced into the spaces between winding wire.

Stock, which consists of fibers entrained in water on the order of 1 part in 200, is delivered to one quadrant of the cylinder mold through a channel partially defined by the upper plate and the lower plate 21 (FIG. 1). The lower plate may be provided with a sealing member 22 which bears against the surface of the face 10 to restrict the area of the face to which stock is delivered. It is conventional to increase the speed of flow of the stock as it approaches more closely to the face, so that its velocity will be approximately the same as the peripheral speed of the cylinder roll when the stock strikes the face. For this purpose, the stock is conventionally directed substantially tangentially of the roll in a channel of gradually decreasing size, as indicated in FIG. 1.

The apparatus so far described is a known type of cylinder machine. However, such machine also includes a shaft upon which the spiders are mounted and which is rotated with such spiders. Though the shaft is conventionally hollow, the central chamber of such shaft is not normally used for any purpose.

In contrast, with the apparatus of the present invention, rather than rotating the shaft with the spiders and the face, the spiders are themselves mounted on a central stationary hollow cylindrical core 25. As will be seen particularly in FIG. 2, the spiders are rotatably supported on the central core by fiber washers 26 which are preferably water-lubricated, as through slots 26', into the fiber washers through the wall of the central core.

The core is also provided with a plurality of slots 27 which extend through its wall into the inner chamber 28. These slots, as shown particularly in FIG. 1 are of generally arcuate shape corresponding in position generally to that of the area of the face to which stock is delivered. As shown in FIG. 2 the slots 27 are of relatively short axial extent, with one slot between each pair of supporting spiders.

These slots 27 mate with passages 29 of generally funnel-shape which are formed by water collectors 30. The water collectors each comprise a ring portion 31 which encircles the core 25 and which is clamped to the core by a conventional type of clamping means shown at 32, and a funnel portion 33 which extends radially outward from the ring portion toward the face 10 of the cylinder. The outermost portion of the funnel portion of each water collector has wall surfaces 34 and 35 (FIG. 1) which are spaced apart by a distance greater than the separation between the edges of the channel formed by plates 20 and 21, through which stock is delivered to the cylinder.

The wall portion 35 is provided with a sealing member 36 which, like the member 22, may be of hard rubber, and which extends to a position immediately adjacent the rods 12, or may even contact such rods to rub thereagainst during rotation of the cylinder. In similar fashion, the wall portion 34 of the funnel-shaped water collector is supplied with a similar type of sealing member 37 which extends outwardly therefrom and which preferably contacts the rods during rotation of the cylinder. Alternatively, this sealing member, like the member 36, may terminate just inward of the rods so that there is no abrasive contact during rotation of the cylinder.

It will be seen that the arcuate portion or quadrant of the periphery of the roll which is delimited by the wall portions 34 and may be divided into two parts. The first part is that to which stock is supplied, and the second part is a portion in advance of the stock entrance segment and which is exposed only to air.

Referring again to FIGS. 1 and 2, it will be seen that the remaining outer wall portions of each water collector 30, namely those axially-separated portions identified at 40 and 41, are positioned immediately adjacent the surfaces of spiders 15. In fact, the spiders 15 have a section of reduced thickness forming ribs 42 which separate the adjacent wall portions 40 and 41 of adjacent water collectors 30. The spiders themselves are of generally arrow-shaped cross section, with a head portion 43 extending radially outward from the rib portion 42. This head portion comes nearly to a point, so that the face 10 is not shielded by the spiders to any substantial extent.

As a result of this construction of the spiders and the water collectors, substantially the entire axial extent of the face is covered by the openings defined by the wall portions 34-35, and 4041, of the water collectors 30.

As shown, particularly in FIGS. 1, 2 and 4, the cylinder machine includes, in addition to the parts so far described, a vat 50 within which the cylinder machine is mounted for rotation, and to which the stock is supplied for formation of the paper sheet on the face 10. The opposite ends of the cylinder are sealed with respect to the walls 51 and 52 of the vat, as by fiber bearing rings shown at 53 and 54 in FIG. 2 and which each have an internal channel within which a sealing O-ring 55 is mounted. Of course the opposite end spiders 13 and 14 rotate with respect to the vat walls 51 and 52, but the sealing structure above described prevents leakage of the stock or of air between these parts.

One end portion 57 of the central core 25 is sealed off, but the other portion is connected to a T connector 58 which has upper and lower discharge openings 59 and 60 designed to be connected to appropriate pipes. As indicated diagrammatically in FIG. 4, the upper flange 59 is connected to the suction side of an air pump or fan shown at 61. This fan is capable of supplying enough of a negative pressure that an added head of the order of, e.g. 17 or 18 inches of water is provided across the face of the cylinder machine. This head adds to the hydraulic head of 6 to 7 inches of water which is normally employed in cylinder mold machines, to encourage both water and air to pass through the face 10 of the cylinder and into the funnel-like passages 29 provided by the water collectors 30. The water and air then pass through the slots 27 into the chamber 28 in the central stationary core 25. The water is then directed out through the opening 60 into an appropriate white water collector schematically indicated at 62 in FIG. 4. As indicated above, the air of course fiows to the suction side of the pump 61 through the opening 59.

As also indicated in FIG. 4 additional stock may be added to the white water discharged into the collector 62, such additional stock being of greater concentration of fibers than the stock supplied to vat 50, in order that the combination of the white water discharge and the added stock will bring the discharge of collector 62 back to the consistency of stock which should be supplied to the vat 50. As indicated, a pump 63 may be provided to supply the appropriate hydraulic head to force the stock into the passage shown in FIG. 1 as defined by the plates 20 and 21.

As is conventional in cylinder machines and :as shown in FIG. 1, the paper sheet which is formed by passage of the white water through the face 10 of the cylinder roll is transferred to a felt generally shown at 70. This felt contacts and drives a couch roll 71 of conventional design. Since the felt is in contact with the cylinder, the cylinder is driven in the same direction as the felt to cause transfer of the formed sheet from the face 10 to the felt 70.

The felt and couch roll 71 need not be further described because they are of conventional and well known form and purpose. It will be evident, however, that with the apparatus of FIGS. 1, 2 and 4, the stock is delivered to a portion of the periphery of the face 10 which is of less circumferential extent than the distance between the seal members 36 and 37 on water collector wall portions 34 and 35. As a result, only moisture from the formed paper sheet and air is drawn through the face from the portion of that sheet between the sealing member 37 and the forward end of the stock passage. This tends to consolidate the fibers of the sheet, as well as to reduce the moisture content thereof, so that the sheet may more easily 'be transferred at high speed to the felt 7 0.

Since the quadrant of the cylinder roll upon which the paper sheet is formed is in effect divided into a part through which water is drawn and a part through which air is drawn, it is possible to completely isolate these two portions and to supply a different or stronger vacuum for the second portion. This approach is illustrated diagrammatically in FIG. 3 wherein the air-portion is isolated from the water-portion by a sealing member 75 forming an extension of a further wall portion 76 of the water collector. The wall portion 76 in turn is connected to a ring portion 77 surrounding a pipe 78. An appropriate passage into the pipe 78 may be provided such that, with a different air pump or fan connected to such pipe, a greater amount of negative pressure may be supplied to the inner surface of the face between the sealing members 37 and 75, and the degree of compression and drainage of the sheet in this area may be increased.

It will be evident that, particularly with larger cylinders, more than two chambers or funnel passages could be provided, and more than two different suction pressures could be supplied.

Though the cylinder machine of the drawings has been illustrated as driven by the felt and couch roll, it will be evident that the cylinder could be directly driven, as for instance by providing the cylinder with a flange upon which a gear is mounted and by driving that gear through conventional motive means.

As was indicated earlier, this invention is particularly applicable to use with cylinder molds, but it is not limited to such use, being in fact of utility whenever it is desired to employ a perforate face of small thickness, with supporting spiders, yet a moderate vacuum is desired to be applied to the face, for the withdrawal of moisture from paper.

It will be evident that many minor changes could be made in the apparatus specifically described herein without departure from the scope of the invention. The invention therefore is not be considered limited to the preferred embodiment disclosed but rather only by the scope of the appended claims.

We claim:

1. Apparatus including a suction roll, for use in paper manufacture, and which comprises a long cylindrical central hollow stationary core forming an axis for the roll,

a pair of end spiders and a plurality of intermediate spiders each rotatably mounted on said core and spaced apart axially therealong,

a wire mesh face of cylindrical shape mounted on said spiders for rotation therewith about said core and forming a porous cylindrical covering for the roll to support paper fibers traveling in the direction of rotation of the roll, along an are extending part way around the periphery thereof,

said core having a plurality of slots each extending between an adjacent pair of spiders and through the wall of the core into its central chamber,

a different water collector mating with each of said slots and extending radially outward therefrom, each said collector defining an inner air and water passage extending from adjacent the inner surface of the face to its respective said slot,

an air pump connected to said central chamber to pump air therefrom so that air and water are pulled through said mesh face into the chamber of said core,

and means for discharging the air and water from said chamber.

2. The apparatus of claim 1 including a plurality of supporting rods coaxial with said core, fixed at their opposite ends to said end spiders and supported intermediate their ends by said intermediate spiders, said rods being spaced apart circumferentially of the spiders to form a supporting framework,

and winding wire wound about the framework of said rods with each wrapping thereof spaced from its adjacent wrapping, said winding wire forming a support for said mesh face.

3. The apparatus of claim 2 in which said water collectors each comprise a sleeve portion encircling and clamped to said core with an opening through said sleeve portion aligned with its respective slot in said core,

and a funnel portion extending radially outward from the sleeve portion and defining said air and water passage.

4. The apparatus of claim 3 in which said funnel portion of each water collector defines an axially-extending opening of substantially the same length as the distance between its next adjacent spiders so that substantially the entire axial extent of a partial circumferential portion of said face is opposite said openings and is therefore exposed to negative air pressure such as to pull water through said face from paper extending along that portion of its outer surface.

5. The apparatus of claim 4 in which said funnel portion of each water collector extends circumferentially in a direction perpendicular to the axis of the roll for only a limited extent and further including seal members mounted at the circumferentially-opposite sides of each said water collector, said seal members each extending axially substantially the entire distance between adjacent spiders and outwardly into close proximity to said mesh face, whereby water is pulled through only a limited circumferential sector of the face during each moment.

6. In apparatus including a cylinder mold for forming a sheet of paper from a stock of paper fibers entrained in water and which comprises a roll composed of a pair of end spiders and a plurality of intermediate spiders sup porting a plurality of axially-extending, arcuately-spaced supporting rods on which is wound a winding wire forming a supporting framework for a wire mesh face; means defining a passageway for delivering stock at approximately the speed of the roll to a circumferentially-limited portion of the periphery thereof, and a moving felt in contact with a portion of the periphery of the roll circumferentially displaced from said limited portion thereof in the direction of movement thereof, to rotate the roll and remove the sheet therefrom;

the improvement comprising a central stationary hollow cylindrical core supporting said spiders to permit rotation of the roll with respect to the core and having axially-spaced slots into its central chamber from its outer periphery, said slots being positioned each between a different pair of adjacent spiders,

a different water collector mating with each of said slots and mounted on and fixed to said central core, each collector defining an inner air and water passage extending from adjacent the inner surface of the face to its respective slot,

an air pump connected to said central chamber to pump air therefrom so that air and water are pulled through said mesh face into the chamber of said core,

and means for discharging air and water from said chamber.

7. The apparatus of claim 6 in which said intermediate spiders are of relatively short axial extent in the radially outermost portion thereof, so that only small portions of the face are shielded thereby,

and said water collectors each include a funnel-like member extending radially inward from adjacent the inner surface of the face to the core and having wall portions defining said passage, the outermost surfaces of said wall portions defining an opening of size at least coextensive and aligned with the portion of said circumferentially-limited periphery of the roll to which stock is delivered between the spiders adjacent thereto, said water collectors being operable to carry away all water which passes through said face, whereby the roll does not rotate in a path of white water, so as to avoid interference with sheet formation thereon.

8. The apparatus of claim 7 in which said discharging means comprises a T-shaped connection to one end of said core chamber,

the other end being closed, with the head of the T extending vertically and the body thereof connected to the chamber,

and pipe means connecting the upper end of the head portion of the T to the suction side of said air pump, water being discharged through the lower end of the head portion of the T.

9. The apparatus of claim 8 in which each water collector has a seal member mounted at the circumferentiallyopposite sides of the walls defining the said opening, said seal members each extending axially substantially the entire distance between the adjacent spiders and outwardly into at least close proximity to the mesh face.

10. The apparatus of claim 9 in which the circumferential spacing between the seal members of each water collector is substantially greater than the circumferential extent to which stock is delivered.

References Cited by the Examiner Sievers 162-369 DONALL H. SYLVESTER, Primary Examiner. S. LEON BASHORE, Examiner.

Claims (1)

1. APPARATUS INCLUDING A SUCTION ROLL, FOR USE IN PAPER MANUFACTURE, AND WHICH COMPRISES A LONG CYLINDRICAL CENTRAL HOLLOW STATIONARY CORE FORMING AN AXIS FOR THE ROLL, A PAIR OF END SPIDERS AND A PLURALITY OF INTERMEDIATE SPIDERS EACH ROTABALY MOUNTED ON SAID CORE AND SPACED APART AXIALLY THERELONG, A WIRE MESH FACE OF CYLINDRICAL SHAPE MOUNTED ON SAID SPIDERS FOR ROTATION THEREWITH ABOUT SAID CORE AND FORMING A POROUS CYLINDRICAL COVERING FOR THE ROLL TO SUPPORT PAPER FIBERS TRAVELING IN THE DIRECTION OF ROTATION OF THE ROLL, ALONG AN ARE EXTENDING PART WAY AROUND THE PERIPHERY THEREOF,

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