Shoe suction press roll

Abstract

This invention relates to a press device with a suction press roll. According to the invention, a linear force increase can be achieved in press devices with suction press rolls of identical or smaller size than conventional suction press rolls by equipping the suction press rolls with a compliance compensator. Said compliance compensator is arranged parallel to the longitudinal axis of the suction press roll in said suction press roll. Different concepts are possible depending on the roll cover construction and the arrangement of the suction box, whereby the one first embodiment is characterized by the integration of a shoe press roll in the suction press roll. A second embodiment is characterized by the combination of a routing of connection channels between the press nip and the suction box through the roll cover with an integrated compliance compensator in the interior space enclosed by the roll cover.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]This invention relates to a press device. Also it relates to a method for converting a press device in order to increase the linear force in an individual press nip, and to a multiple-nip press device.[0003]2. Description of the Related Art[0004]Press sections on machines for producing fibrous webs are already known in numerous embodiments from the prior art. Different press concepts are realized depending on the number of press nips to be passed through and on the arrangement and construction of the rolls forming said press nips. In the individual press devices the press nips are created by way of two rolls, whereby one of the rolls can be constructed for example as a shoe press roll. From publication EP 1 445 375 A1 there is already known for example a Duo Nipcoflex arrangement. On said arrangement the fibrous web is passed in the region of the press section successively through two press nips which are formed by two ...

AI Technical Summary

Benefits of technology

[0014]According to a particularly advantageous embodiment, the flexible press cover of the shoe press roll is made from a wear-free or high wear-resistant material in order to prevent unnecessary replacement of the flexible belt.

[0016]A second embodiment of the inventive solution consists of combining in one press roll two concepts known from the prior art. This is achieved in that the suction device no longer becomes active in the interior space and hence the fluid-gas mix no longer needs to be passed into the interior space of the press cover in order to be discharged from there but is passed directly through the press cover and evacuated preferably at the side in the region of the end faces. As the result, the inner face describing the inner circumference of the press cover can be kept closed, whereby the closed construction makes it possible to resort here to pressing-on units which enable the linear force to be established in particular over the width or parallel to the longitudinal axis of the press roll. This is achieved in that provision is made for pressing-on units which include one or a multiplicity of pressing-on elements which become active at the inner circumference or exert a pressure on said inner circumference in the direction of the press nip and hence create a bracing force in relation to the mating roll. Here it is possible, depending on the embodiment, to combine different sub-variants with each other.

[0021]According to a particularly advantageous further aspect, the inventive solution is used for suction press rolls on press devices for which provision is made for at least two suction press rolls of the same type on one press device. Compared to conventional suction press rolls without an inventive compliance compensator, inventive suction press rolls with identical or smaller diameter can be used for the same establishable line forces, which means that a simple replacement of conventional suction press rolls by inventively constructed suction press rolls is also possible for effecting a linear force increase.

Problems solved by technology

If said linear force is to be increased on a press device, it is necessary as a rule in the case of conversions to provide a larger suction press roll diameter, which in part cannot be installed at all or only at great expense in the existing construction space, which is fixed by the presence of additional devices such as ducts, doctor blades and supports, thus making complex conversions necessary or limiting the possibility of a linear force increase.

Images