EP0745725B1 - Roller press - Google Patents

Abstract

Roller press, calender etc. has three rollers min. forming pressure gaps to process fabric web (2) where one (3) has a very flexible casing rotating about a fixed carrier (4) on which it is mounted via at least one support element (6) with a concave surface (7) guaranteeing a broad pressure gap (1) with a counter cylinder (8). The latter forms another gap (15) with at least one flexurally non-controlled roller (14) and its casing's (9) outer circumference reduces axially from roller mid-point to ends. Also claimed is a like second roller press where the feature of the counter roller's casing is that it rotates about a fixed carrier (10) and, at its ends can not be moved against, but is mounted via at least one support element (11) on, the carrier. The elements act in a direction which, while being set at an insignificant angle, DELTA , out of the pressure plane formed with the first roller (3), is tilted w.r.t. the third roller forming the other pressure gap. Also claimed is third roller press similar to the last where the feature of the counter roller's support elements is that, along with the opposing main roller elements (6), they are so arranged and activated that the main roller exerts greater resultant compressive force in opposing that from the counter roller. Pref. the circumference of the main roller's casing and of the third roller reduces axially from roller mid-point to ends by pref. the same amount. All rollers circumferences taper off similarly to those of the preferred first press. Alternatively the counter roller's circumference does not alter. Angle DELTA is between 2 and 15, pref. 4 and 8 degrees and varies from roller mid-point to ends. All roller circumferences of taper off similarly to those of the preferred second press, angle DELTA has the same features and support elements are similarly tilted. Opposing support elements are singly, in groups or all together connected to a common pressurised fluid pipe. It is guaranteed that the main roller exerts greater compression in opposing counter roller force by fluid pressure reducing devices and the ratio of the areas of the opposing support elements.

Description

The invention relates to a roller press or the like, consisting of at least three forming several press nips Rolls, according to the preambles of claims 1, 3 or 9, such as in drainage or smoothing a fibrous web is used.

Such a roller press is known for example from WO 93/12289.

In the roller press known from WO 93/12289 is used as a counter roller a deflection adjustment roller is provided.

In "Pulp And Paper Manufacture, Third Edition, Volume 7, Paper Machine Operations ", pages 263 and 264, Canada, 1991 with a roller press consisting of two rollers mentioned that at least one of the two rollers can be cambered in order for the between these two rolls formed a single press nip a uniform Get pressure profile.

Especially if the mating roller with a third one does not deflection-controlled roller interacts, as this also in particular in the case of WO 93/12289 known roller press the case, there may be difficulties in formation a straight, uniform press nip as possible the roll deflection.

It is possible to put the counter roller or the third roller in the press level with support elements for deflection control to provide the roll shell of these rolls, however, requires this is a considerable effort. You can also considerable with the usual hydraulic support elements thermal problems arise if the counter roll and / or the third roller to improve drainage or Smoothing result is heated.

The invention is therefore based on the object of a roller press to create that even without deflection control a largely uniform press nip between the Counter roll and at least one other roller allows.

According to the invention the object is achieved by the in the claims 1, 3 and 9 described devices solved, the Represent subclaims special embodiments. In all cases there is a roller press or the like from at least three several press nips to treat one Rolls of material forming rolls, one of which is a press roll a very flexible, rotatable around a fixed carrier Roll shell consists of at least one support element is mounted on the carrier, which is a concave, a wide nip with the cylindrical counter roller ensuring Has support surface, the counter roller at least with a non-deflection controlled roller forms further press nip.

In order not only between the press roll and the counter roll but also between the counter roll and at least one other deflection-controlled roller as far as possible The invention offers a uniform press nip three independent, but also in combination with each other applicable solutions. All these have in common that the Roll jacket of the counter roll axially reinforced in the central area is bent towards the further roller. Be reached this can be done in that, on the one hand, the outer circumference of the Roll jacket of the counter roll starting from the middle of the roll reduced in axial direction towards the roller ends and / or that the counter roller also from a fixed to a Carrier rotatable roller jacket is made of at least one support element is mounted on the carrier.

In the latter case, if the other roller is not accurate is arranged opposite the press roll by a slight Inclination of the direction of action of the support element of the counter roller at an angle from that formed with the press roll Press plane to a further press nip with the counter roll forming roll a deformation of the roll shell of the Counter roll can be reached. Because of the generally existing Fixation of the roll jacket ends of the counter roll, if anything, just a shift of the roll shell allowed within the press plane with the press roll results is reinforced by the inclination of the support elements Deformation of the roll shell of the counter roll in the axially middle Area radially towards the further roller, with on this side of the press plane, of course, several rollers can be arranged.

Regardless of whether the support element of the counter roller is accurate acts towards the press roll or the directions of action of each other opposite support elements of the press roll and the counter roll are aligned with each other or the support element the counter roll from the press plane formed with the press roll is inclined, if the other rollers in the opposite the press nip between the counter roll and the press roll Semicircle area (based on the roll cross section) attack the counter roller, increased deflection the counter roll in the axially central area to the further roller preferably be achieved in that the opposing support elements of the press roll and the Counter roll are designed and / or acted upon, that compared to the contact pressure exerted by the counter roller results in a greater contact pressure of the press roll. Here are the opposite support elements of the press and the counter roll preferably individually, in groups or in total connected to a common fluid pressure line, devices reducing via the fluid pressure and / the size ratio of the support surfaces of the opposite Support elements opposite to that of the counter roller outgoing contact pressure ensures greater contact pressure of the press roll becomes. This is due to the fact that the roller shell the counter roll at its ends radially immovable is stored against the carrier.

Especially when the outer circumference of the roll shell the counter roll, starting from the roll center, in axial Reduced towards the roller ends, it is from Advantage if the circumference of the roll shell of the press roll and / or a further press nip with the counter roll forming roller starting from the center of the roller in the axial Direction towards the roller ends also preferably in reduced to the same extent. This allows the degree of circumferential reduction to be kept to a minimum so that the Speed differences on the roller surface, in seen in the axial direction, reduce. It will also Differences in speed at the roller surface minimized or excluded between the corresponding rollers.

If the direction of action of the support element from the press plane is inclined, the angle of inclination should be between 2 and 15, preferably between 4 and 8 degrees. For reinforcement the deformation of the roll shell of the counter roll in the axial middle range, i.e. it is in the area of the machine center also an advantage if the angle is from the center of the roller starting in the axial direction towards the roller ends changed, especially tended to shrink.

Figur 1

einen schematischen Querschnitt durch eine Walzenpresse mit drei Walzen und

Figur 2

einen schematischen Längsschnitt dieser Walzenpresse einschließlich der Fluidsteuerung.

The invention will be explained in more detail below using an exemplary embodiment. The attached drawing shows:

Figure 1

a schematic cross section through a roller press with three rollers and

Figure 2

a schematic longitudinal section of this roller press including the fluid control.

The roller press consists of three approximately one above the other arranged and in a chair, not shown stored rollers, the two press nips 1 and 15 for treatment form a material web 2. While the press roll 3 is located exactly above the counter roller 8, the third is as Suction roller trained roller 14 offset to this press level arranged below the counter roller 8. To this roller press particularly suitable for dewatering a fibrous web make, run through the press nips 1 and 15 next to the Material web 2 dewatering felts 16 for receiving the squeezed Water.

The press roll 3 consists of a very flexible one fixed carrier 4 rotatable roller jacket 5, the over a hydraulic support element 6 in the form of an axially extending Bar is mounted on the carrier 4, the support element 6 has a concave support surface 7. Instead of one is mounted on a hydraulic pressure pad it is of course also possible to use several support elements 6 bring to. The lubrication of the gap between the Support surface 7 and the inner surface of the roll shell 5 can be done hydrostatically and / or hydrodynamically.

The concave support surface 7 makes it relatively wider Press nip 1 formed with the approximately cylindrical counter roller 8. This also consists of a fixed one Carrier 10 rotatable roller jacket 9, which over several Support elements 11 is mounted on this. So that between the counter roller 8 and the third roller 14 as possible uniform press nip 15 forms, decreases the outer circumference of the roll shell 9 of the counter roll 8, of starting from the middle of the roller, in the axial direction to the roller ends out, so that the sagging of the third roller 14th can be followed even with large roller widths. To do that Measure of the change in circumference and thus also the change in speed on the roll surface along the counter roll To minimize 8, the scope of the Roll shell of the third roller 14 to the roller ends in same dimensions as the counter roll 8. This also achieved that there was no difference in speed the roll shell surfaces between the counter roll 8 and The third roller 14 comes, which negatively affects the treatment result the material web 2 could impact. From the same The reason also decreases in the case of the press roll 3 Scope of the roll shell 5 to the roll ends in the same Dimensions (change in circumference, based on the circumference). The change the circumference of the roll can be changed by changing the inside diameter the roller shells 5, 9 and / or the wall thickness this roll shells 5, 9 can be achieved. Complementary or for on its own, however, it is also possible to roll the roller shells 5, 9 thermally from the inside, for example via the lubricating fluid the support elements 6, 11, and / or outside, for example inductive to influence accordingly and so a change in scope bring about. The same naturally applies to the third roller 14.

As an independent or - as here - complementary measure the direction of action of the support elements 11 slightly by one Angle Δ, which is between 2 and 15, preferably 4 and 8 degrees, lies from the press plane 3 formed with the press roll which forms a further press nip 15 with the counter roll 8 Roll 14 inclined. Since the roller jacket 9 of the counter roller 8 is fixed at the ends via bearings on the carrier 10, acts resulting from the inclination of the support elements 11 Deformation of the roll shell 9 of the counter roll 8 particularly strongly in the middle area, so that the roller jacket 9 there deformed more towards the third roller 14. This The effect becomes even more pronounced if the angle Δ, of starting from the middle of the roller, in the axial direction to the roller ends downsized. It can also be an advantage the angle A, for example via a controllable rotatability the carrier 10 (with the associated support elements 11) to make the counter roller 8 variable so as to influence on the degree of deformation of the roll shell 9 of the counter roll 8 to be able to take.

The fluid supply of the support elements 6 and 11 of the press and Counter roll 3.8 is simply done via a common fluid pressure line 12, being between the fluid pressure line 12 and the support elements 11 of the counter roll 8 each Throttle is located. This creates a larger contact pressure guaranteed at the press roll 3, so that the Roll end mounted roll jacket 9 of the counter roll 8 in middle area down, i.e. to the third roller 14 deflects. This also has a beneficial effect on education a uniform second press nip 15. The bigger one Contact pressure of the press roll 3 with respect to the counter roll 8 can but also about the size ratio of the support surfaces 7th the opposite support elements 6, 11 of both Reach rollers.

Claims (17)

1. Roll press, calender or the like, consisting of at least three rolls which form a plurality of press gaps (1, 15) for the treatment of a material web (2), of which one press roll (3) consists of a very flexible roll jacket (5) rotatable about a stationary carrier (4) and supported on the carrier (4) by at least one support element (6), the support element having a concave support surface (7) which ensures a broad press gap (1) with one cylindrical counter roll (8), wherein the counter roll (8) forms at least one further press gap (15) with a roll (14) without deflection control, characterised in that the outer periphery of the roll jacket (9) of the counter roll (8) becomes smaller in the axial direction towards the end of the rolls, starting from the middle of the roll.
2. Roll press in accordance with claim 1, characterised in that the periphery of the roll jacket (5) of the press roll (3) and/or of the roll (14), which forms a further press gap (15) with the counter roll (8), reduces in the axial direction to the roll ends, starting from the roll middle, preferably to the same degree.
3. Roll press, calender or the like, consisting of at least three rolls which form a plurality of press gaps (1, 15) for the treatment of a material web (2), of which one press roll (3) consists of a very flexible roll jacket (5) rotatable about a stationary carrier (4) and supported on the carrier (4) by at least one support element (6), the support element having a concave support surface (7) which ensures a broad press gap (1) with a cylindrical counter roll (8), wherein the counter roll (8) forms a further press gap (15), at least with one roll (14) without deflection control, which is not arranged precisely opposite to the press roll (3) and wherein the counter roll (8) consists of a roll jacket (9) rotatable about a stationary carrier (10), which is supported on the carrier by at least one support element (11), characterized in that the roll jacket (9) is non-displaceably mounted at its ends relative to the carrier (10), in that the direction of action of the support element (11) is slightly inclined by an angle (Δ) out of the pressing plane formed with the press roll (3) towards the roll (14) which forms a further press gap (15) with the counter roll (8).
4. Roll press in accordance with claim 3, characterised in that the outer periphery of the roll jacket (9) of the counter roll (8) reduces in the axial direction towards the roll ends starting from the roll middle.
5. Roll press in accordance with claim 3 or claim 4, characterised in that the periphery of the roll jacket (5) of the press roll (3), and/or of the roll (14), which forms a further press gap (15) with the counter roll (8), reduces in the axial direction towards the roll ends, starting from the roll middle, preferably to the same degree.
6. Roll press in accordance with claim 3 or claim 5, characterised in that the periphery of the roll jacket (9) of the counter roll (8) does not change in the axial direction.
7. Roll press in accordance with one of the claims 3 to 6, characterised in that the angle (Δ) lies between 2° and 15°, preferably between 4° and 8°.
8. Roll press in accordance with one of the claims 3 to 7, characterised in that the angle (Δ) reduces in the axial direction towards the roll ends starting from the roll middle.
9. Roll press, calender or the like, consisting of at least three rolls which form a plurality of press gaps (1, 15) for the treatment of a material web (2), of which one press roll (3) consists of a very flexible roll jacket (5) rotatable about a stationary carrier (4) and supported on the carrier (4) by at least one support element (6), the support element having a concave support surface (7) which ensures a broad press gap (1) with a cylindrical counter roll (8), wherein the counter roll (8) forms a further press gap (15), at least with one roll (14) without deflection control, wherein the further press gap (15) is formed in the semi-circular region of the counter roll (8), relative to the roll cross-section of the counter roll (8) lying opposite to the press gap (1) between the counter roll (8) and the press roll (3), wherein the counter roll (8) consists of a roll jacket (9) rotatable about the stationary carrier (10), and supported on the carrier (10) via at least one support element (11); and wherein the support elements (6, 11) of the press roll (3) and of the counter roll (8) lie opposite to one another, characterized in that the roll jacket (9) of the counter roll (8) is non-displaceably mounted at its ends relative to the carrier (10) and in that the support elements (6, 11) of the press roll (3) and of the counter roll (8) are so laid out and/or loadable that a greater pressing force of the press roll (3) results relative to the contact pressing force which originates from the counter roll (8).
10. Roll press in accordance with claim 9, characterised in that the outer periphery of the roll jacket (9) of the counter roll (8) reduces in the axial direction towards the roll ends starting from the roll middle.
11. Roll press in accordance with claim 9 or claim 10, characterised in that the periphery of the roll jacket (5) of the press roll (3), and/or of the roll (14), which forms a further press gap with the counter roll (8), reduces in the axial direction towards the roll ends, starting from the roll middle, preferably to the same degree.
12. Roll press in accordance with claim 9 or claim 11, characterised in that the circumference of the roll jacket (9) of the counter roll (8) does not change in the axial direction.
13. Roll press in accordance with one of the claims 9 to 12, characterised in that the direction of action of the support element (11) is inclined fractionally by an angle (Δ) out of the press plane formed with the press roll (3) towards the roll (14), which forms a further press gap (15) with the counter roll (8).
14. Roll press in accordance with claim 13, characterised in that the angle (Δ) lies between 2° and 15°, preferably between 4° and 8°.
15. Roll press in accordance with claim 13 or claim 14, characterised in that the angle (Δ) changes in the axial direction towards the roll ends, starting from the roll middle.
16. Roll press in accordance with one of the claims 9 to 15, characterised in that the oppositely disposed support elements (6, 11) of the press roll (3) and of the counter roll (8) are connected individually, groupwise or as a whole to a common fluid-pressure line (12), wherein, via devices (13) which reduce the fluid pressure and/or via the size-ratio of the support surfaces (7) of the oppositely disposed support elements (6, 11), a greater contact pressure force of the press roll (3) is ensured relative to the contact pressure force originating from the counter roll (8).
17. Roll press in accordance with one of the claims 9 to 12 and 16, characterised in that the directions of action of the oppositely disposed support elements (6, 11) of the press roll (3) and of the counter roll (8) are at least substantially aligned with one another.

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