ES2333175T3

ES2333175T3 - PRESS ROLLER WITH SHOE.

Info

Publication number: ES2333175T3
Application number: ES07122713T
Authority: ES
Inventors: Eckart Krageloh; Christian Muller
Original assignee: Voith Patent GmbH
Current assignee: Voith Patent GmbH
Priority date: 2007-02-17
Filing date: 2007-12-10
Publication date: 2010-02-17
Anticipated expiration: 2027-12-10
Also published as: ATE443178T1; DE502007001535D1; EP1959052A1; EP1959052B1; PL1959052T3; DE102007008037A1

Abstract

The press roller has a flexible roller cover (1) pressed by a press shoe (2) with a concave press surface for formation of a press gap in a direction of an impression roller. The press shoe has outer, central and inner layers (3, 4, 5) lying one upon the other in a press direction. The central layer has an increased compressibility and a modulus of elasticity of 5-50 MPa. The outer and inner layers are made of steel. The central layer is made of a compressible material i.e. plastic. The press shoe is pressed to the impression roller by a hydraulic pressing piston (6).

Description

Rodillo de prensado con zapata.Press roller with shoe.

La invención concierne a un rodillo de prensado para alisar o drenar una banda de papel, cartón, tisú u otro material fibroso en una máquina para la fabricación y/o el afinamiento de la misma, el cual comprende una envolvente de rodillo flexible que es presionada por una zapata de prensado con superficie de prensado cóncava en dirección a un rodillo antagonista a fin de formar una rendija de prensado, comprendiendo la zapata de prensado tres capas situadas una sobre otra en la dirección de prensado, de las cuales la capa central presenta una elevada compresibilidad.The invention concerns a pressing roller to smooth or drain a band of paper, cardboard, tissue or other fibrous material in a machine for manufacturing and / or the refining it, which comprises an envelope of flexible roller that is pressed by a pressing shoe with concave pressing surface in the direction of a roller antagonist in order to form a press slit, comprising the three layer pressing shoe located one above the other in the pressing direction, of which the central layer has a high compressibility

Las zapatas de prensado de una sola pieza consisten predominantemente en bronce o en acero. En rodillos antagonistas con un contorno defectuoso resultan entonces evoluciones irregulares de la fuerza lineal.One piece pressing shoes They consist predominantly of bronze or steel. On rollers antagonists with a defective contour then result irregular evolutions of linear force.

Dado que la zapata de prensado no es suficientemente flexible, se plantean problemas de adaptación especialmente en el borde.Since the pressing shoe is not sufficiently flexible, adaptation problems arise especially on the edge.

Las capas intermedias conocidas en zapatas de prensado sirven predominantemente para el aislamiento térmico y no proporcionan una flexibilidad suficiente.The intermediate layers known in shoes pressing serve predominantly for thermal insulation and not They provide sufficient flexibility.

No obstante, si se hace que la zapata de prensado sea demasiado flexible, se amplifica entonces la ondulación de la presión lineal entre los pistones de apriete, lo que, sobre todo al drenar la banda de material fibroso, conduce a una mayor ondulación del perfil transversal de la humedad.However, if the shoe is made of pressing is too flexible, then the ripple is amplified of the linear pressure between the tightening pistons, which, about all when draining the band of fibrous material, leads to greater undulation of the transverse profile of moisture.

Se conoce por el documento WO2004/011721 un rodillo de prensado con zapata que lleva una zapata de prensado que está formada por tres capas, de las cuales la capa central tiene una elevada compresibilidad.It is known from WO2004 / 011721 a press roller with shoe that carries a press shoe that It consists of three layers, of which the central layer has a high compressibility

Por tanto, el problema de la invención consiste en incrementar la flexibilidad de la zapata de prensado sin que resulte perjudicado el perfil de la fuerza lineal.Therefore, the problem of the invention consists in in increasing the flexibility of the pressing shoe without the profile of the linear force is impaired.

Según la invención, el problema se ha resuelto haciendo que la capa central presente un módulo E comprendido entre 5 y 50 MPa.According to the invention, the problem has been resolved. causing the central layer to have a module E comprised between 5 and 50 MPa.

En particular, la zapata de prensado consta de tres capas situadas una sobre otra, de las cuales la central presenta una elevada compresibilidad y tiene un módulo E comprendido entre 5 y 50 MPa.In particular, the pressing shoe consists of three layers located one above the other, of which the central It has a high compressibility and has an E module included between 5 and 50 MPa.

Debido a la capa central elástica, la zapata de prensado resulta más flexible, de modo que ésta se pueda adaptar al contorno del rodillo antagonista. La estabilidad de la capa interior y de la capa exterior cuida entonces de que no se incremente la ondulación de la presión lineal entre los pistones de apriete.Due to the elastic central layer, the shoe pressing is more flexible, so that it can be adapted to the antagonist roller contour. The stability of the inner layer and the outer layer then takes care not to increase the Ripple of the linear pressure between the tightening pistons.

Para que las ventajas de las capas se extiendan de manera correspondiente a la acción total, las capas deberán presentar un espesor que esté comprendido entre 15 y 45%, preferiblemente entre 20 y 40% del espesor de la zapata de prensado.So that the advantages of the layers are extended corresponding to the total action, the layers must have a thickness that is between 15 and 45%, preferably between 20 and 40% of the thickness of the shoe pressing.

Puede ser ventajoso a este respecto que las capas presenten aproximadamente el mismo espesor.It may be advantageous in this regard that layers have approximately the same thickness.

En interés de una posibilidad de fabricación sencilla, pero también de la garantía de una estabilidad de forma suficiente de la zapata de prensado, al menos una capa, preferiblemente la exterior y especialmente la capa exterior y la capa interior deberán consistir en acero.In the interest of a manufacturing possibility simple, but also the guarantee of stability of form enough of the pressing shoe, at least one layer, preferably the outer and especially the outer layer and the Inner layer should consist of steel.

Para conseguir una compresibilidad suficiente de la capa central, la capa compresible deberá estar hecha de un material compresible, especialmente plástico, preferiblemente de un material con un coeficiente de dilatación transversal de menos 0,5, y/o la capa compresible deberá poseer escotaduras, preferiblemente ranuras que discurran en la dirección de avance de la banda.To achieve sufficient compressibility of the central layer, the compressible layer should be made of a compressible material, especially plastic, preferably of a material with a coefficient of transverse expansion of minus 0.5, and / or the compressible layer should have recesses, preferably slots that run in the forward direction of the band.

La zapata de prensado deberá ser presionada aquí hacia el rodillo antagonista por al menos una fila de pistones de apriete o elementos de apriete similares dispuestos axialmente uno al lado de otro.The pressing shoe should be pressed here towards the antagonist roller by at least one row of pistons of tightening or similar tightening elements arranged axially one next to each other.

En el caso de rendijas de prensado que requieran una alta precisión, especialmente en el caso de rendija de prensado largas, es ventajoso, para formar una evolución deseada de la presión de prensado en la dirección de avance de la banda, que, considerado en dicha dirección de avance de la banda, varias filas, preferiblemente dos filas de pistones de apriete que discurran transversalmente a la dirección de avance de la banda estén dispuestas una tras
otra.In the case of pressing slits that require high precision, especially in the case of long pressing slits, it is advantageous to form a desired evolution of the pressing pressure in the direction of advance of the belt, which, considered in said direction of advance of the band, several rows, preferably two rows of tightening pistons that run transversely to the direction of advance of the band are arranged one after
other.

Para limitar la ondulación de la presión lineal entre los pistones de apriete a causa de la capa central elástica, la distancia entre los centros de los pistones de apriete de una fila deberá estar situada entre 1,5 y 2 veces el diámetro de los pistones de apriete. A esta distancia se obtiene una distribución relativamente plana de la fuerza lineal.To limit the linear pressure ripple between the tightening pistons because of the elastic central layer, the distance between the centers of the tightening pistons of a row should be located between 1.5 and 2 times the diameter of the tightening pistons At this distance you get a distribution relatively flat linear force.

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Para garantizar una evolución deseada de la presión incluso en los bordes, la distancia entre el borde de la zapata de presión situado transversalmente a la dirección de avance de la banda y el centro del pistón de apriete más exterior deberá estar comprendida entre 0,75 y 1 veces el diámetro de los pistones de apriete.To ensure a desired evolution of the pressure even at the edges, the distance between the edge of the pressure shoe located transversely to the direction of travel of the band and the center of the outermost tightening piston should be between 0.75 and 1 times the diameter of the pistons Of tightening.

A continuación, se explicará la invención con más detalle haciendo referencia a un ejemplo de realización. Muestran en el dibujo adjunto:Next, the invention will be explained with more detail referring to an embodiment example. They show in the attached drawing:

La figura 1, una sección transversal esquemática a través de la zona del borde de una zapata de prensado 2 yFigure 1, a schematic cross section through the edge area of a pressing shoe 2 and

La figura 2, una vista en planta esquemática de la zapata de prensado 2 con pistones de apriete 6.Figure 2, a schematic plan view of the pressing shoe 2 with tightening pistons 6.

El rodillo de prensado mostrado en las figuras tiene una envolvente de rodillo flexible 1 hecha de plástico reforzado con fibras, la cual es presionada por una zapata de prensado 2 hacia un rodillo antagonista cilíndrico 9. Dado que la zapata de prensado 2 posee una superficie de prensado cóncava vuelta hacia el rodillo antagonista 9, la envolvente 1 del rodillo puede adaptarse al contorno del rodillo antagonista 9.The pressing roller shown in the figures it has a flexible roller 1 envelope made of plastic fiber reinforced, which is pressed by a shoe pressing 2 towards a cylindrical antagonist roller 9. Since the pressing shoe 2 has a concave press surface turned towards the antagonist roller 9, the envelope 1 of the roller can adapt to the contour of the antagonist roller 9.

Tiene lugar así la formación de una rendija de prensado alargada que, a causa del prolongado tiempo de permanencia de la banda de material fibroso en la rendija de prensado, permite un tratamiento de la banda de material fibroso que resulta ser intenso, pero que, no obstante, cuida bien del volumen.Thus the formation of a slit of elongated pressing which, due to the prolonged residence time of the band of fibrous material in the pressing slit, allows a treatment of the band of fibrous material that turns out to be intense, but that nevertheless takes good care of the volume.

Mientras que, para el alisado, la banda 1 de material fibroso corre solamente a través de la rendija de prensado, se tiene que, al drenar la banda de material fibroso, una o varias cintas de drenaje preferiblemente en forma de fieltros de prensado son guiadas a través de la rendija de prensado para absorber el agua exprimida en esta última.While, for smoothing, band 1 of fibrous material runs only through the press slit, you have to drain the band of fibrous material, one or more drainage belts preferably in the form of pressing felts they are guided through the press slit to absorb water squeezed into the latter.

El apriete de la zapata de prensado 2 se efectúa por medio de dos filas de pistones de apriete hidráulicos 6 dispuestos axialmente uno al lado de otro. Las filas situadas una tras otra en la dirección 10 de avance de la banda, tal como se muestra en la figura 2, permiten influir sobre la evolución de la presión de prensado en la dirección 10 de avance de la banda dentro de la rendija de prensado.Pressing shoe 2 is tightened by means of two rows of hydraulic clamping pistons 6 arranged axially side by side. The rows located a after another in the forward direction 10 of the band, as shown in figure 2, allow to influence the evolution of the pressing pressure in the forward direction 10 of the band inside of the press crack.

Para mejorar la flexibilidad de la zapata de prensado 2, ésta consta de tres capas 3, 4, 5, una capa interior 5 de acero, una capa central compresible 4 hecha de un plástico compresible y una capa radialmente exterior 3 hecha también de acero.To improve the shoe's flexibility Pressed 2, this consists of three layers 3, 4, 5, an inner layer 5 of steel, a compressible central layer 4 made of a plastic compressible and a radially outer layer 3 also made of steel.

Las capas 3, 5 de acero confieren la estabilidad de forma necesaria a la zapata de prensado 2 y contrarrestan una ondulación demasiado grande de la evolución de la presión lineal en la rendija de prensado.Steel layers 3, 5 provide stability necessarily to the pressing shoe 2 and counteract a too large undulation of the evolution of linear pressure in The pressing slit.

En interés de una compresibilidad suficiente de la capa central, el plástico empleado para ella tiene un módulo E lo más pequeño posible comprendido entre 5 y 50 MPa y un coeficiente de dilatación transversal de menos de 0,5.In the interest of sufficient compressibility of the central layer, the plastic used for it has an E module as small as possible between 5 and 50 MPa and a coefficient of transverse dilatation of less than 0.5.

Para que las capas 3, 4, 5 produzcan su plena acción, éstas tienen aproximadamente el mismo espesor.For layers 3, 4, 5 to produce their full action, these have approximately the same thickness.

La distancia entre los pistones de apriete 6 de una fila es lo más pequeña posible a fin de minimizar la ondulación de la evolución de la presión lineal transversalmente a la dirección 10 de avance de la banda. En la realización mostrada en la figura 1, los centros de pistones de apriete contiguos 2 tienen una distancia 8 de algo más de 1,5 veces el diámetro de los pistones de apriete 2.The distance between the tightening pistons 6 of a row is as small as possible in order to minimize undulation of the evolution of linear pressure transversely to the direction 10 advance of the band. In the embodiment shown in the figure 1, the adjacent tightening piston centers 2 have a distance 8 of just over 1.5 times the diameter of the pistons of press 2.

Para minimizar defectos en el borde, la distancia 7 entre el centro del pistón de apriete más exterior 2 y el borde asciende aproximadamente a 0,75 veces el diámetro del pistón de apriete 2.To minimize edge defects, the distance 7 between the center of the outermost tightening piston 2 and the edge amounts to approximately 0.75 times the diameter of the tightening piston 2.

Claims

1. Pressing roller to smooth or drain a paper, cardboard, tissue or other fibrous web in a machine for manufacturing and / or fine-tuning it, which comprises a flexible roller envelope (1) that is pressed by a pressing shoe (2) with a concave pressing surface in the direction of an antagonist roller (9) in order to form a pressing slit, the pressing shoe (2) comprising three layers (3, 4, 5) located one over another in the pressing direction and especially said shoe consisting of three layers located one above the other in the pressing direction, of which the central layer (4) has a high compressibility, characterized in that the central layer (4) has a module E between 5 and 50 MPa.

2. Pressing roller according to claim 1, characterized in that the layers (3, 4, 5) have a thickness that is between 15 and 45%, preferably between 20 and 40% of the thickness of the pressing shoe (2).

3. Press roller according to claim 1 or 2, characterized in that the layers (3, 4, 5) have approximately the same thickness.

4. Press roll according to any of the preceding claims, wherein at least one layer (3, 5), preferably the outer layer (3) and especially the outer layer (3) and the inner layer (5) are steel.

5. Press roller according to any of the preceding claims, characterized in that the compressible layer (4) is made of a compressible material, especially plastic, preferably of a material with a transverse expansion coefficient of less than 0.5.

6. Pressing roller according to any of the preceding claims, characterized in that the understandable layer (4) has recesses, preferably grooves running in the direction (10) of the advance of the web.

7. Pressing roller according to any of the preceding claims, characterized in that the pressing shoe (2) is pressed towards the antagonist roller (9) by at least one row of clamping elements arranged axially side by side, especially pistons of tighten (6).

8. Pressing roller according to claim 7, characterized in that several rows of clamping pistons (6), preferably two rows thereof, are arranged one after another in the direction of advance of the web.

9. Press roller according to claim 7 or 8, characterized in that the distance (8) between the centers of the tightening pistons (6) of a row is between 1.5 and 2 times the diameter of the tightening pistons ( 6).

10. Pressing roller according to any of claims 7 to 9, characterized in that the distance (7) between the edge of the pressing shoe (2) located transversely to the forward direction (10) of the belt and the center of the piston The outermost tightening pressure (6) is between 0.75 and 1 times the diameter of the tightening pistons (6).