EP1496152A1 - Press roller or a roller sleeve - Google Patents

Abstract

A papermaking assembly has a dewatering press drum (2) operating against a shoe (6) drum (3) with a mantle (7) and forming a sandwich nip for a wet web (5) between two felt webs (4, 5). The drum (7, 2) has a series of circumferential grooves in which the ratio of depth to width is no more than 8. The ratio of depth to width is preferably 5, e.g. 4 mm depth or less and 0.6 mm or more. The drum surface can hold up to 1300 cm of water per 1 m drum surface area. The grooves occupy up to 39% of the drum surface area. The drum surface further incorporates an array of blind holes (8).

Description

The invention relates to a press roll or a roll shell of a Shoe press roll and a pressing device in a press section of a machine for producing a paper, board, tissue or another fibrous web a pulp suspension with grooved depressions on its mantle surface for storing press water.

From DE 100 22 087 A1 a press section for a paper machine is known. The press section has two pressing points, each of one with a Shoe press roller co-acting press roller can be formed. By the first Pressstelle run a first upper felt, coming from a Formersiebende Paper web, an underfelt and a press cover of a first shoe press roll therethrough. The underfelt continues with the paper web to the second press site. Together with a second top felt and a press cover of a second Pressing point, the paper web then passes through the second pressing site. The paper web follows the lower felt further to a take-off roll, through which they is transferred to a first dryer fabric, the paper web in the dryer section transferred. For deflecting the upper felt and the lower felt are guide rollers and Suction rolls available.

The mantle surface of the press rolls and the press jackets of the shoe press rolls are each equipped with blind holes to drain the out of the Paper web to squeeze out extruded water.

On the other hand, it is also known press rolls with grooves or both grooves and To provide blind holes to allow the outflow of press water.

DE 100 55 708 A1 discloses a method and a device for Drainage on its outer surface with depressions, in particular grooves, described described circumferential pressing surface, by the mantle of a rotating press roll or a revolving press belt of a paper machine is formed. In the recesses of the pressing surface an air flow is generated, by remaining in the wells, not by centrifuging away Water is carried out of the wells out to the outside. Subsequently the surface water is stripped off the pressing surface.

In the known press rollers, the grooves have a width of about 0.5 mm and a depth of 5 mm; the grooves are so narrow in relation to their depth. As a result, the storage volume of the known press rollers for receiving the Press water not optimally designed. It turns out that in the operation of the Available storage volume can not be fully utilized. To the one, the water when filling the grooves, d. H. during the short-term Pressing process in the press nip, do not fill the grooves to the bottom of the groove. Another one Problem arises in particular in high-speed paper machines in the way that the grooves between the Nipauslauf and Nipeinlauf as completely as possible must be emptied in order during the next pressing process the accruing To be able to absorb water. This is at high speeds Paper machine not sufficiently possible if the grooves are quite deep. Also the measures proposed for example in DE 100 55 708 A1, namely generating an airflow to move water out of the wells are not sufficient to achieve this.

It is the object of the invention, a press roll, a roll shell a Shoe press roll and a pressing device to provide, which is a ensure improved drainage in the press nip.

According to the invention, this object is achieved with a press roll or a Roll shell of the type mentioned solved in that the press roll or the roll shell in the web running direction has a groove or grooves, the one Ratio of their depth to their width of at most 8 has or have.

The selected according to the invention ratio between width and depth of the grooves allows a complete or almost complete filling with press water and thus allows an optimal utilization of the volume of the grooves Available storage volume. The grooves extend substantially transverse to the longitudinal axis of the press roll in the running direction of the fibrous web, in the direction the longitudinal axis or obliquely to the longitudinal axis. If only a single groove exists is, this spiral or helical runs on the lateral surface with a free selectable angle with respect to the longitudinal axis of the roller.

The inventive geometry of the grooves and the subsequent Removing the press water from them relieved, causing the drainage of the Fiber web is also promoted.

Advantageous developments emerge from the dependent claims, the Description and the drawings.

In an advantageous development, it is provided that the ratio of the depth to Width is at most 5.

It is particularly advantageous if the depth is 4 mm or less and the width is 0.6 mm or more.

Particularly suitable is a press roll or a roll shell, in or at the the grooves have a depth of 0.8 mm and a width of 2.2 mm.

By uniform spacing of grooves with the dimensions described above results in a storage volume on the mantle surface of the press roll or the roll mantle of 660 cm ³ and more, based on 1 m ^{2 of} the mantle surface.

In another embodiment of the press roll or the roll mantle, a storage volume on the mantle surface of the press roll or shoe press roll of 1100 cm ³ or more is achieved, based on 1 m ^{2 of} the mantle surface of the press roll or of the roll mantle.

In a further advantageous embodiment of the press roll or of the roll mantle, a storage volume on the mantle surface of the press roll of 1300 cm ³ or more is achieved, based on 1 m ^{2 of} the mantle surface.

In an advantageous embodiment of the press roll or the roll shell the grooves cover at least 25% of the mantle surface of the press roll.

In another embodiment of the press roll cover the grooves at least 33% of the mantle surface.

In an embodiment of the press roll, with which even more press water is removed, The grooves take 39% or more of the mantle surface of the press roll or Roll mantle.

Advantageously, the storage volume is increased by blind holes, which on the Cloak surface are evenly distributed between the grooves.

In a further embodiment of the press roll or the roll mantle are also the grooves are included in the area where the blind holes are located. Thus, these are on the mantle surface also within the grooves or with a Intersection of the grooves evenly distributed.

To be able to remove dirt from the mantle surface is additional at least one scraper on the press roll or the outer surface of the shell Roll mantle arranged.

It proves to be particularly advantageous if at least one blow doctor at the Press roll or is provided on the roll shell. Come next mechanically acting on the outer surface of the roller scraper used. Blasschaber and scraper can also be used in combination with each other.

Advantageously, the geometry of the grooves is already designed so that due to the Centrifugal force self-emptying of the grooves is possible.

The invention is particularly advantageous at high speeds, such as at speeds of 1400 m / min and more, at speeds of more than 1700 m / min and above all at speeds of more than 1800 m / min. By comparison with the prior art in relation to the depth greater width The grooves can be this even at higher speeds with water fill. On the other hand, the centrifugal force is affected at higher speeds stronger, which promotes the emptying of the grooves.

The invention also relates to a pressing surface for use in a Pressing device, on a pressing device with two press rollers, wherein one of the both rollers may be a shoe roll or both rollers shoe rolls and on the press section equipped with such press rolls is.

Likewise, the invention relates to the use of a press roll in the inventive design in a press section, in particular with a Tandem arrangement, each with a press roll in conjunction with a Shoe press roll.

Fig. 1a

eine schematische Seitenansicht eines Ausschnitts der Presswalze, die mit einer Schuhpresswalze zusammenwirkt,

Fig. 1b

eine schematische Schnittansicht der Rillen in der Mantelfläche,

Fig. 2

eine Draufsicht auf die Oberfläche der Presswalze,

Fig. 3

ein Diagramm, in dem die Breite B der Rillen als Funktion der Tiefe T aufgetragen ist,

Fig. 4

eine schematische Seitenansicht eines Ausschnitts einer weiteren, mit einer Schuhpresswalze zusammenwirkenden Presswalze,

Fig. 5

die Anordnung eines Blasschabers bez üglich der Mantelfläche einer Walze,

Fig. 6, 7

Längsschnitte durch Walzenrohre mit einer Rillenstruktur auf der Mantelfläche der Walze,

Fig. 8

einen Längsschnitt durch ein Walzenrohr mit einer von einer Profil-Spirale gebildeten äußeren Beschichtung,

Fig. 9a - d

Querschnitte von Rillen und

Fig. 10

eine schematische Ansicht einer Pressenpartie.

The invention will be explained in more detail in exemplary embodiments with reference to the drawings. Show it:

Fig. 1a

a schematic side view of a section of the press roll, which cooperates with a shoe press roll,

Fig. 1b

a schematic sectional view of the grooves in the lateral surface,

Fig. 2

a plan view of the surface of the press roll,

Fig. 3

a diagram in which the width B of the grooves is plotted as a function of the depth T,

Fig. 4

FIG. 2 is a schematic side view of a detail of another press roller cooperating with a shoe press roll; FIG.

Fig. 5

the arrangement of a blow doctor with respect to the lateral surface of a roller,

Fig. 6, 7

Longitudinal sections through roller tubes with a groove structure on the lateral surface of the roller,

Fig. 8

a longitudinal section through a roller tube with an outer coating formed by a profile spiral,

Fig. 9a - d

Cross sections of grooves and

Fig. 10

a schematic view of a press section.

From a wire section is a fibrous web 1 (Fig. 1a) to a pressing or a press nip guided in a press section, which has a press roll 2. These interacts with a shoe roll 3. Two felts 4 and 5 go through together with the fibrous web 1 the press nip. In the inlet into the press nip or press nip is the fibrous web 1 on the lower felt 4. It can, however, also With reference to FIG. 1, DE 100 22 087 A1 is represented by a forming wire of FIG Coming Siebpartie be sucked by a suction roller to the upper felt and be transported over this to the press nip. The press nip becomes the Fibrous web 1, for example, as shown in Fig. 1a, in conjunction with led out the lower felt 4.

The shoe roll 3 comprises a down against the press roller 2 pressed Press shoe 6, which is convexly formed opposite to the press roller 2. On the Press shoe 6 runs off a roll shell 7. In these are for the better Water discharge over the entire lateral surface of the roll shell 7 distributed, at least, as far as this interacts with the felt 5, blind bores 8 introduced, which are only partially reproduced here. Alternatively, in the Roll shell 7 grooves or both grooves and the blind holes 8 available.

The grooves are preferably in the circumferential direction of the roll shell 7; alternative they run transversely to the circumferential direction of the roll shell 7 and thus transversely to the Conveying direction of the fibrous web 1. In another embodiment of the Roll mantle 7 is provided that the grooves obliquely over the circumference of the Roll mantle 7, in particular helical, run. Alternatively, only one runs only groove helical over the roll shell 7. In addition, at all Embodiments blind holes 8 may be present.

As shown with reference to Fig. 1b, the grooves 10 have a width B and a Depth T in the shell of the roll 2 or in the roll shell 7. The grooves 10 have preferably in each case the same distances to each other; but you can too different distances depending on the expected water attack during the pressing process.

At least one scraper or water scraper is employed on the press roll 2, the free water from the lateral surface of the press roll 2 abstreift. The scraper can be arranged at a small distance to the lateral surface, so that he with this does not come into contact. In one embodiment of the invention is a blow doctor provided, through which air is blown on the lateral surface, which turns out the water the grooves 10 and the holes 11 in the roll shell of the press roll. 2 pushes. (For the sake of simplicity, the blind holes in Fig. 2 are only partially shown.)

The grooves 10 are depending on the embodiment of different densities on the lateral surface the press roller 2 applied, wherein depth and width of the grooves 10 is a ratio of at most 8: 1, preferably 5: 1, to each other. Also number and Diameter of the blind holes 11 may vary.

The blind holes 11 are between the grooves 10 in the lateral surface of the Press roll 2 introduced to assist the drainage. The Blind holes 11 may also be the lateral boundaries of the grooves 10 be exceeded or arranged on the bottom of the grooves 10.

In Fig. 3 areas are shown in which according to the invention, the Move dimensions of the grooves 10. In this case, the depth T of the grooves 10 in Millimeters plotted on the x-axis and the width B also in millimeters the y-axis. The ratio of the width B and the depth is defined by an area 20 between a straight line 21 through the zero point and the y-axis wi edergegeben. Particularly preferred is a region 22, between a straight line 23 and the y-axis. Also preferred is a region 24 above a straight line 25 that is parallel to the x-axis runs and the y-axis intersects at a value of B = 0.6 mm.

The areas 20, 22, 24 are delimited by a straight line 26, which is the maximum Depth of 4 mm and parallel to the y-axis. A preferred measure a groove is for example B = 0.8 mm and T = 2.2 mm and is by a Item 27 in the diagram.

In another variant of the invention, the fibrous web 1 (FIG. 4) is first pulled together with the upper felt 5 in the press nip and is sandwiched, d. h., Adjacent to both the lower and the upper felt 4, 5, from the Pressnip led out. Only after leaving the area of the press roll 2 and the Shoe press roll 3, the fibrous web 1 by a suction roll 12 together with the lower felt 4 at an acute angle to the horizontal direction deflected down, while the upper felt 5 horizontally to a guide roller thirteenth is continued.

On the inlet side of the press nip are a blowing scraper 14 and a on the Surface of the press roller 2 acting scraper 15 arranged on the one hand the Remove water from the grooves 10 and the blind holes 11 and on the other hand to remove dirt from the surface of the press roll 2. It can several scraper blade 14 and scraper 15 on the press roller 2 in different Arrangements be made.

The blow doctor 14 (FIG. 5) is fastened to a holder 16, which under one acute angle to the lateral surface 16 of the press roller 2 is inclined. The scraper 14 preferably extends over the entire, covered by the paper web 1 Width of the press roll 2; or alternatively, it is a plurality of blowing blades 14 arranged next to each other. The blow doctor 14 comprises a supply pipe 18 for Supply of compressed air from individual openings 18a in the jacket wall of the Supply pipe 18 emerges and from a narrow gap 19 in the immediate Close to the outer surface of the press roller 2 is pressed out on this. The compressed air can alternatively be heated to t> + 0 ° C to t = 100 ° C to increase the viscosity of the To reduce the grooves located in the water and thus the groove drainage in addition to support.

Instead of the blowing blade 14, a suction scraper may be present, the by means of vacuum sucks impurities and water. In this case, that will Vacuum provided via the supply pipe 18.

The press roll 2 has, for example, a surface with grooves 10, as shown in FIG. 6 are shown. These are in an outer, applied to a roll tube 30 Layer 31 arranged, for example, milled. The outer layer 31 is made for example, steel, especially stainless steel, or bronze. The roller tube 30 is made of steel or cast iron.

In a further embodiment, the outer layer 31 consists of a Plastic, for example polyurethane. This particular has a hardness of about 4 P & J (hardness unit after Pusey and Jones).

In another embodiment (Figure 7), the grooves 10 are directly in the Roller tube 30 introduced, made of steel, in particular stainless steel, gray cast iron or Bronze exists. In both embodiments, both in this and in the 6 embodiment described between the grooves 10th or this anschneidend also blind holes are present.

In Figure 8, a so-called profile spiral 32 is shown, which consists of a plastic or a metal and helically on a roller tube 33 of a roller 34 is wound so that the coming into contact with one of the felts 4, 5 Area of the press roll 2 completely occupied by a helically extending groove 10 is. This does not exclude that the profile spiral 32 also include blind holes can. The profile spiral 32 producing band has a substantially L-shaped Cross section, so that by juxtaposing the turns of the Profile spiral 32 a continuous groove 10 having a substantially rectangular Cross-section arises. The groove 10 may, for example, by cutting off arise.

When the cover which is applied to the roller tube 34, from a flexible Material exists, creates an additional degree of freedom in the design of the Groove shape. The flexible cover can also be easily exchanged to replace it with another with a different groove structure.

A particular advantage of such a reference is also that under Line pressure extended the press zone with the jacket 7 of the shoe press roll 3. at sufficient flexibility of the plastic used can also be the coat 7 out of the plastic. When looking through the use of a flexible material the line pressure increases, the drainage is increased, and at the same time the felts 4, 5 are spared.

A plurality of possibilities for the design of the cross section of helically extending groove 10 or parallel or at least in substantially parallel grooves 10 is shown in Figs. 9a to 9d.

According to the embodiment of Fig. 9a, both the upper edges 35 of the Grooved 10 and the bottom edges 36 rounded. The variant of FIG. 9b has rectangular grooves 10, while the grooves 10 in Fig. 9c a have trapezoidal cross-section. The grooves 10 in Fig. 9d also have one trapezoidal cross-section with rounded upper edges 35.

The invention can be in a press section of a machine for producing a Fiber web in pressing arrangements 40, 41 (FIG. 10), consisting of a Press roll and a shoe press roll, both for the press roll and for the Insert roll jacket of shoe press roll. Likewise, she agrees Use double shoe presses.

Coming from the wire section is a paper web 43, which from an upper felt 44 is guided, together with a lower felt 45 in the pressing assembly 40th introduced. The paper web 43 is then in a sandwich together with the lower felt 45 and the upper felt 44 to a suction roll 46 from the Press nip brought out. About a further suction roller 47, it is then sucked on an upper felt 48 again. Together with this and one another lower felt 49 is inserted into the press assembly 41. Subsequently the paper web 43 is again conveyed in a sandwich up to a suction roll 50, from it is transported together with the upper felt 48 in a drying section 51, while the lower felt 49 is deflected down again.

The invention is an effective even at high production speeds Water absorption in the shell of a press roll or a shoe press roll allows, as by a sufficient width of the groove or grooves and / or the Blind holes the water penetrates into this quickly enough and through the Pressing pressure in the area of the press shoe and the adhesion to the bottom of the press shoe Depressions penetrates. On the other hand, the drainage is just at high Speeds supported by the centrifugal force. In addition, can be but use scraper and blower. The latter work either with Negative pressure to suck the water out of the wells. Or they blow Compressed air into the wells to aid in their evacuation.

The invention thus relates to those with grooves and / or blind holes equipped jacket of both a shoe press roll and a press roll and on a press arrangement as well as on a press section in which such Press arrangements and such press rolls and shoe press rolls used come.

The press rolls are for example profile rolls, d. H. by bending controlled Rolls, so called Nipco-P-rolls, or Nipcoflex-rolls, like them already known from DE 100 55 708 A1.

Instead of the illustrated in Fig. 10 embodiment of a press section can be the press arrangements also use in a tandem arrangement, in which at the first press point the shoe press roll above and the press roller arranged below are at the second press site, the press roll above and the Shoe press roller are mounted below, or vice versa.

Claims (22)

Press roll (2) or roll shell (7) of a shoe press roll (3) in a press section of a machine for producing a paper, board, tissue or another fibrous web (1) from a pulp suspension with depressions on its mantle surface for storing press water,
characterized in that
the press roll (2) or the roll shell (7) in the web running direction has at least one recesses (10) designed as grooves (10) or grooves, which has or have a ratio of their depth to their width of at most 8. Press roll (2) or roll shell (7) according to claim 1,
characterized in that
the ratio of depth to width is at most 5. Press roll (2) or roll shell (7) according to claim 1,
characterized in that
the depth is 4 mm or less and the width is 0.6 mm or more. Press roll (2) or roll shell (7) according to claim 2,
characterized in that
the depth is 0.8 mm and the width is 2.2 mm. Press roll (2) or roll shell (7) according to one of claims 1 to 4,
characterized in that
the storage volume on the mantle surface of the press roll (2) or of the roll mantle (7) is 660 cm ³ or more, based on 1 m ^{2 of} the mantle surface of the press roll (2) or of the roll mantle (7). Press roll (2) or roll shell (7) according to one of claims 1 to 4,
characterized in that
the storage volume on the mantle surface of the press roll (2) or the roll mantle (7) is 1100 cm ³ or more, based on 1 m ^{2 of} the mantle surface of the press roll (2) or of the roll mantle (7). Press roll (2) or roll shell (7) according to claim 6,
characterized in that
the storage volume on the mantle surface of the press roll (2) or of the roll mantle (7) is 1300 cm ³ or more, based on 1 m ^{2 of} the mantle surface of the press roll (2). or the roll shell (7). Press roll (2) or roll shell (7) according to one of claims 1 to 7,
characterized in that
the grooves (10) at least 25% of the mantle surface of the press roll (2) and the roll shell (7). cover. Press roll (2) or roll shell (7) according to one of claims 1 to 7,
characterized in that
the grooves (10) cover at least 33% of the mantle surface of the press roll (2) or the roll mantle (7). Press roll (2) or roll shell (7) according to one of claims 1 to 7,
characterized in that
the grooves (10) cover at least 39% of the mantle surface of the press roll (2). Press roll (2) or roll shell (7) according to one of claims 1 to 10,
characterized in that
on the mantle surface blind holes (11) are evenly distributed between the grooves (10). Press roll (2) or roll shell (7) according to one of claims 1 to 11,
characterized in that
on the mantle surface within the grooves (10) or with a cut of the grooves (10) blind holes (11) are evenly distributed. Press roll (2) or roll shell (7) according to one of claims 1 to 12,
characterized in that
at least one scraper (15) is arranged on the mantle surface for removing soiling of the press roll (2) or of the roll mantle (7). Press roll (2) or roll shell (7) according to claim 13,
characterized in that
at least one blow doctor (14) on the roll surface or on the roll shell (7) is employed. Press roll (2) according to one of the preceding claims, characterized in that
it has a roll tube (30) made of steel, in particular stainless steel, gray cast iron or bronze. Press roll (2) according to claim 15,
characterized in that
the roller tube (30) has a shell-side layer (31) made of steel, in particular stainless steel, or bronze or of plastic, in particular of polyurethane. Press roller (2) according to claim 15 or 16,
characterized in that
it has at least one groove (10), in particular a helical or spiral groove (10), which has a rectangular or trapezoidal cross-section, in particular with rounded edges (33, 34). Press roll (2) or roll shell (7) according to one of claims 1 to 15,
characterized in that
on the lateral surface a helical groove (10) is formed from a plastic spiral having a substantially L-shaped cross-section. Use of a press roll (2) or a roll mantle (7) after one of claims 1 to 18 in a press section, in particular with a Tandem arrangement, each with a press roll (2) in conjunction with a Shoe press roll. Press arrangement, consisting of a press roll (2) and a shoe press roll (3) with a roll shell (7), characterized in that
at least the press roll (2) and / or the roll shell (7) is designed according to one of claims 1 to 18. Press section in a machine for producing a fibrous web with at least one press arrangement according to claim 20. Press section in a machine for producing a fibrous web, characterized in that
at least the first press nip is formed by a press arrangement according to claim 20.

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