US2929450A - Suction roll for drying pulp webs, more especially in the paper and cellulose industry - Google Patents

Description

March 22, 1960 w, u z 2,929,450

SUCTION ROLL FOR DRYING PULP WEBS, MORE ESPECIALLY IN THE PAPER AND CELLULOSE INDUSTRY Filed July 7, 1958 4 Sheets-Sheet l .w all INVENTOR. M M

March 22, 1960 w, u z 2,929,450

SUCTION ROLL FOR DRYING PULP WEBS, MORE ESPECIALLY IN THE PAPER AND CELLULOSE INDUSTRY Filed July 7, 1958 4 Sheets-Sheet 2 INVENTOR:

Adm M 111,

March 22, 1960 w, uRz 2,929,450

- SUCTION ROLL FOR DRYING PULP WEBS, MORE ESPECIALLY IN THE PAPER AND CELLULOSE INDUSTRY Filed July 7. 1958 4 Sheets-Sheet 3 INV R.

. BY a I.

March 22, 1960 A. w. KURZ 2,929,450 SUCTION ROLL FOR DRYING PULP WEBS, MORE ESPECIALLY IN THE PAPER AND CELLULOSE INDUSTRY Filed J l 7, 1958 J w 9,, mxnu nugiv' j -26 2s 24 28 E 30 A M ewt'y. f

n 24 26 27 m m INVENTOR.

euin 4 Sheets-Sheet 4 SUCTION ROLL FOR DRYING PULP WEBS, MQRE ESPECIALLY IN THE PAPER AND CELLULOSE INDUSTRY Anton W. Kurz, Ravensburg, Germany, assignor to Escher Wyss G.m.b.H., Ravensburg, Germany, a corporation of Germany Application July 7, 1958, Serial No. 746,706 Claims priority, application Germany July 18, 1957 11 Claims. cr.' 162-370).

This invention relates to a suction roll for drying pulp webs, more especially in the paper and cellulose industry, wherein at least one suction chamber has its longitudinal walls, which extend in the direction of the axis of the roll, and its transverse walls adjoining the inner face of the shell of the suctionroll through a packing surface;

The suction rolls known in the construction of paper machines consist substantially of a cylindrical perforatedouter shell, which is rotatable about a suction chamber or two suction chambers. The longitudinal and transverse walls of these suction chambers adjoin the inner faceof the wall of the-suction roll through packings consisting of a suitable material. The pulp. web to be dried. is guided by means of an endless sieve or felt over that sector of the shell of the suction roll within which the suction chambers subjected to the action of a vacuum which can be varied as desired bearagainst the said shell. Under the action of the vacuum, water is sucked from the pulp web into the suction chambers and then discharged. If two suction chambers are provided, one is generally adjusted to a higher vacuum, and the other to a lower vacuum.

A construction is known in which a longitudinal wall of the suction chamber is rotatable, that is to say, movable in the circumferential direction of the'suction roll, whereby the size of the surface of the suction zone can be varied with constant width in the axial direction of the roll.

In another known construction of a suction roll, a device is provided for adaptation to varying pulp web widths. In this case, there are disposed in the-suction box, which must have fixed longitudinal walls for this purpose, piston-like partitions limiting the suctionzone, which are displaced in accordance with the width of the pulp-web.

' The described devices for the adjustment of the suction zone in width and those for the adjustment in length cannot be simultaneously provided in the known suction rolls. The aim of the invention is to obviate these'disadvantagesand to render possible an adjustment of the suction zone to meet all operating requirements and more particularly an adaption of the suction zones to the width of the pulp web. In a suction roll of the type hereinbefore described, there are provided for this-pun pose at least 'two axially extending walls which are disposed in the interior of. the suction roll shell and are independently rotatable about the axis thereof. These walls laterally define between each other a suction chamher, which is open toward the suction rollshell. Packing means are provided between the said walls which allow relative angular displacement thereof. while maintaining a fluid tight seal.

Constructionalexamples of the subject of the invention are illustrated in simplified form in the drawings, in which:

Figure 1' is a cross-section through the central portion of a suction roll.

2,929,450 Patented Mar. 22,- 1966 Figure 2 is a section through an end portion of the suction roll along the line IIII of Figure l-. I

Figures 3, 4 and 5 are cross-sections through other constructional forms of suction rolls. Figures 6 and 7 are axial longitudinal sections through the end of the shell of the. suction roll along the line VI-VI of Figure 1, showing difierent positions of a masking ring on a larger scale,

Figure 8 is an axial longitudinal section through the end of the shell of the suction roll along the line VIII-- VIIIof Figure l, and

Figures 9 and 10 are cross-sections along the lines IX-IX of Figure 6 and X-X of Figure 7 respectively. The suction roll for a paper making machine as illustrated in Figs. 1 and 2 has a perforated suction roll shell '8. Arranged in the interior of the shell 8 is asuction box which comprises hollow cylinders 1, 1 2 and}, between which there are rings 4, 5 and 6, and in addition a ring 7. The hollow cylinders 1, 1 2 and 3 are arranged coaxially With the suction roll shell 8. The

. tion roll.

Between the rings 4, 5, 6, 7 and the corresponding rings 4 5 6 7 there are provided in the radial and walls 13,14, 15,16, 17 which extend axial direction of the roll. These walls have circumferentially spaced longitudinal edges in close proximity to the interior surface of the suction roll shell 3'. 'Soft 'packings are provided between these edges. of the walls 13, 14, 15 16, 17 and the interior surface of the shell 8. I

The wall 14 is a radial extension of the cylinder-1 which passes through apertures inthe cylinders 1, ZY-and 3. The wall 13 is aradial extension of the cylinder 2, which passes through the aperture of cylinder 3, and-the walls 15, 16,17 are radial extensions of the cylinder-3.

Cylinder 1 is rigidly connected to cylinder 1* by means of a wall 12 traversingv the the two cylinders. The apertures in the cylinders. 2 and 3 through which the walls 14 and 13 pass, are-wide enough to allow relative angular displacement between the walls 13, 14 and 15. i

The wall 13 with the cylinder 2 on one hand and the wall 14 with the cylinder 1 the wall 1 and the cylinder 1 on the other hand form walls which laterally dc fine a suction chamber 10 which is open toward'the-suction roll shell 8. This chamber lll is axially closed: by the rings 4, 5, 6, 7 and 4 5 6 7 Thecylindersl and 2 are so packed as to be rotatable relatively to-"one another by means of rubber sheets 18, 19 which extend in the axial direction of the suction roll over the entire length of the suction chamber 10s In this, way relative angular displacement of cylinders land 2 is allowed while afiuid tight seal is maintained. i V 1 Similarly there is formed between the-walls 14* and 15 a suctionchamber 11 which communicatesthrough the apertures in the cylinders 1, 2 and 3, withthe in terior of cylinder 1 In order to obtain a fiuid tigh't seal in any relative position of the cylinders 2 and 3, they are packed by means of rubber sheets 29,21. The rubi9, 20, 21 are connected to the correspond 1 situated at the other end of the roll,

intermediate space between nected to the opposite cylinder wall.

-10 and 11 remains constant.

cylinder 1 The cylinder 1 may be constructed as a supporting shaft for the suction roll.

The rubber sheets 18 to 21 are movable in themselves and are connected to the hollow cylinders only at their circumferential extremities. As the hollow cylinders rotate relatively to one another they roll over the surfaces of the hollow cylinders.

' The walls 16 and 17 define between themselves a third suction chamber 12. The rubber sheet 21 serves for the temporary sealing of the suction chamber 12 from the vacuum. However, when the suction chambers 10 and 11 are reduced to a given size, the sheet 21 frees the communication between the suction chambers 11 and 12, so that the chamber 12 is under the same vacuum as the chamber 11. The walls 15, 16, 17 are fixed to the same cylinder 3. The chamber 12 is thus rotatable as a .whole. Its walls are not displaceable in relation. to one another. The rings 4, 5, 6 and 7 serve as transverse walls of the suction chambers 10, 11 an 2- In chamber 12 comprising walls fixed in relationto one another there may also be provided in a manner knownper se piston-like partitions displaceable in the axial direction of the suction roll, by means of which partitions the suction zone may be adapted to the width of the pulp web.

1 With the described construction the walls of the suc- Qtion chambers and consequently the suction zones can be adjusted in an extremely simple manner at any time by rotation of the hollow cylinders 1, 2, 3 as required 'in accordance with the particular operating conditions inv the drying of pulp web. In addition, the ends of the shell of the suction roll remain freely accessible for the :provision of a device for adaption of the suction zone to the width of the pulp web.

The hollow cylinders l, 2, 3 are mounted one within the other by means of the intermediate rings 5, 5 and 6, 6 The ball bearings 9 ensure ready movability of the hollow cylinders relative to one another. The ring 7 guides the hollow cylinder 3 in the shell 8 of the suction roll.

The constructional form illustrated in Fig. 3 difiers from that illustrated in Fig. 1 only in the fact that the innermost cylinder 1 is dispensed with. The wall 14 traverses the interior space of the cylinder 1 and is con- Two compartments 10 11 are thus formed within cylinder 1, the first communicating with the suction chamber 10 and the second with the suction chamber 11. The end walls of the'cylinder 1 have separate drainage holes 10 11 one for each of the said compartments.

In the constructional form according to Fig. 4 the third vacuum chamber 12 is omitted. No walls 16 and 17 are provided.

Fig. 5' shows an embodiment inwhich onlythe hollow cylinders 1 and 2 are provided. The walls 13 and are connected to the cylinder 2. Wall 14 is connected to the hollow cylinder 1 inthe same way as in Figs. 3

and 4. The two cylinders'are rotatable independently of one another, but angular displacement of the walls 13 and 15 in relation to one another is not afforded. The total circumferential area of the suction chambers Relative angular displace- The rods25 are disposed in the axial direction of the roll and extend beyond the ring 24 toward mid-length of the shell 8 of the suction roll by an amount equal to the length of the said ring. When the said masking ring is in the outer position the rods 25 sub-divide the tree annular clearance 29 provided for the ring 24 into individual areas. The apertures 30 formed in the shell of the suction cylinder to receive the rods 25 extend beyond the region of the annular clearance 29 to an amount corresponding to the length of that portion of therods which extends beyond the ring 24.

' In Fig. 6 the masking ring 24 is shown in its outermostv position, the pulp web 32 extending over the entire area of the holes in the suction'roll.

In Fig. 7, on the other hand, the masking ring 24 18 shown displaced completely inward, so that some of the holes in the suction roll are covered and the suction zone is thus reduced tothe width of the narrower pulp web 33. a

I What is claimed is:

1. In a suction roll for drying a pulp web, having a perforated cylindrical rotatable suction roll she ll over which said pulp web passes; suction box comprising at least two bodies arranged in the interior of said suction roll shell coaxially therewith and extending longitudinally of the suction roll shell, each of said bodies comment between walls 14 and 13, 15, however, alters the ratio of the suction areas of chambers. 10 and 11.

Figs. 6 to 10 show means for adapting the suction zone to the width of the pulp web. A masking ring 24 is disposed in the ends of the shell of the suction roll.

Cylindrical rods 25 comprising driving members 26 are I mounted on this masking ring. An axially displaceable disc 27 engages in the driving members 26 The shell 8 of the suction roll comprises a bush 28, an annular clearance 29 for the ring 24 and apertures 30. A sieve 31 supporting a pulpweb 32, 33 tl hvels over the shell 8 of the suction roll.

prising a wall having longitudinal edges in close proximity to the interior surface of the suction roll shell, said walls defining between each other a suction chamber which is open toward the suction roll shell; annular support ng and guide means arranged near the ends of the suction roll shell allowing independent angular displacement of each of said bodies coaxially with the suction roll shell; resilient packing means between said bodies which allow relative angular displacement thereof while maintaining a fluid tight seal; means for axially closing said suction chamber whereby at least one aperture is left for drainage.

axial direction is disposed therein.

3. The combination defined in claim 2 in which the making ring is provided with rods disposed in the axial direction, extending beyond the said ring and sub-dividing the annular clearance of the section roll shell into individual areas, the shell of the suction roll being formed with apertures extending over the area of the annular clearance to receive the said rods.

4. In a suction roll for drying a pulp web, having a perforated cylindrical rotatable suction roll shell over which said pulp web passes; a suction box comprising a series of at least two radially spaced hollow cylinders arranged in the interior ofsaid suction roll shell and coaxially there with; annular supporting and guide means allowing said hollow cylinders to rotate about their axes independently of one another; partitions extending longitudinally of the suction" roll, at least one beingassociated with each of said hollow cylinders and rigidly connected therewith, and said partitions having circumferentially spaced longitudinal edges in close proximity to the interior surface of they suction roll shell and circumferentially consecutive partitions defining between one another a suction chamber which is open toward the suction roll shell; means for axially closing said chamber, while allowing angular displacement of thesaidhollow cylinders and partitions;

' packing means which allow relative angular displacement of the hollow cylinders and the associated partitions while maintaining a fluid tight seal; and means for the discharge of liquid from the suction chamber.

5. The combination defined in claim 4 in which each of said partitions is connected to the associated hollow cylin der along its entire length and an aperture of sufficient width traversed by the partition 7 is provided in each cylinder which encloses the associated cylinder so as to allow relative angular displacement.

6. The combination defined in claim in which at least one resilient sheet extending throughout the lengths of the suction chamber is provided for sealing the said chamber, said sheet being arranged in the radial space between said hollow cylinders, one peripheral end of the said sheet being connected to the inner one and the other peripheral end to the outer one of said cylinders, whereby relative angular displacement of the said cylinders is afiorded while maintaining a fluid tight seal.

7. in a suction roll for drying a pulp web having a perforated cylindrical rotatable suction roll shell over which said pulp web passes; a suction box comprising two radially spaced hollow cylinders arranged in the interior of said suction roll shell and coaxially therewith; annular supporting and guide means allowing the said hollow cylinders to rotate about their axes independently of one another; a first partition extending longitudinally of the suction roll, having one longitudinal edge in close proximity to the interior surface of the suction roll shell and the other longitudinal edge connected to the outer one of said hollow cylinders; a second partition extending longitudinally of the suction roll, having one longitudinal edge in close proximity to the interior surface of the suction roll shell and the other longitudinal edge connected to the inner one of said hollow cylinders, and an aperture being provided extending over part of the circumference of the outer hollow cylinder, through which the said second partition passes, thereby allowing relative angular displacement of the said first and said second partition; the said partitions defining between them a suction chamber which is open toward the suction roll shell; means for closing said suction chamber axially; a flow connection between said suction chamber and the interior of said inner cylinder and a flow connection for discharging liquid from said inner cylinder; and a flexible, sealing sheet arranged in the space between said cylinders connected with respective ends to said cylinders so as to allow relative angular displacement of said cylinders while maintaining a fluid tight seal.

8. The combination defined in claim 7 in which a third partition is provided which has one longitudinal edge in close proximity to the interior surface of the suction roll shell and the other longitudinal edge connected to the outer one of said hollow cylinders, a second suction chamber thus being defined between said second and said third partitions, which is open toward the suction roll shell; the said second partition extending through the inner hollow cylinder so as to divide its interior into two compartments, each communicating with one of said suction chambers and being provided with discharge orifices for drainage.

9. In a suction roll for drying a pulp web having a perforated cylindrical rotatable suction roll shell over which said pulp web passes: a suction box comprising three radially spaced hollow cylinders arranged in the interior of said suction roll shell and coaxially therewith; annular supporting and guide means allowing the said hollow cylinders to rotate about their axes independently of one another; a first, a second, and a third partition extending longitudinally of the suction roll, each having one longitudinal edge in close proximity to the interior surface of the suction roll shell and the other longitudinal edge connected to one of said cylinders, namely the first partition to the outermost cylinder, the second partition to the innermost cylinder and the third partition to the intermediate cylinder, an aperture being provided in the intermediate cylinder which is traversed by the second partition, and the outermost cylinder having an aperture which is traversed by the second and the third partition, said apertures having sufiicient width to allow relative angular displacement of the partitions; two suction cham ers open toward the suction roll shell over a controllable ,circumferential extent thus being defined between said partitions, namely one between said first and said second partition and the other between said second and said third partition; said second partition traversing the innermost hollow cylinder so as to divide its interior into two compartments, veach communicating with one of said suction chambers and provided with discharge orifices for drainage; means for closing the suction chambers axially; and at least one longitudinally extending flexible, sealing sheet arranged in each of the intermediate spaces between said hollow cylinders and connected at respective ends to the adjacent cylinders so as to allow relative angular displacement of the cylinders while maintaining a fluid tight seal.

10. The combination defined in claim 9 in which a part of the said second partition is formed by a tube which is arranged within the innermost cylinder and coaxially therewith and has an opening toward one of said suction chambers so as to allow fluid removed by suction to be discharged through said tube.

11. The combination defined in claim 9 in which at least one further partition is connected to the outermost cylinder so that an additional suction chamber is formed, and an aperture is provided in said outermost cylinder; and in which there is a flexible, sealing strip, said strip within a limited range of the relative positions of the outermost and intermediate cylinders, serving to close the last named aperture.

References Cited in the file of this patent UNITED STATES PATENTS 1,754,822 Farnsworth Apr, 15, 1930 2,199,455 Berry May 7, 1940 2,641,972 Engert June 16, 1953 2,714,342 Beachler Aug. 2, 1955 FOREIGN PATENTS 1,005,825 Germany Apr. 4, 1957

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