Voith Sulzer Papiermaschinen Gmbh

Voith Sulzer Papiertechnik Patent Gmbh

Rainer Bentele

Christian Schiel

Wolf Gunter Stotz

Hans Prinzing

Press device and method of using the same for treating a fibrous material web that includes a shoe press unit that includes a flexible press belt that revolves around a non-rotating carrier, a counter roll that includes a deflection compensation roll with a roll jacket revolving around a second non-rotating carrier, a third roll, a roll nip formed between the counter roll and the third roll, a press nip elongated in a web travel direction and formed between the shoe press unit and the counter roll, at least one first support element where the flexible press belt is supported on the non-rotating carrier by the at least one first support element in the region of the elongated press nip, at least one second support element where the roll jacket is supported on the second non-rotating carrier by the at least one second support element in the region of the elongated press nip. A changeable pressure differential occurs between internal pressures generated by the at least one first support element acting on the flexible press belt of the shoe press unit, and the at least one second support element acting on the roll jacket of the counter roll.

Press device and method of using the same

The invention relates to a roll press including at least three rolls forming several press nips for the treatment of a web of material. One press roll comprises a very flexible roll shell which is rotatable around a fixed support and is mounted on the support by at least one support element which has a concave support surface for defining a wide press nip with a cylindrical backing roll. The backing roll forms an additional press nip with at least one not sag-controlled roll. To obtain as uniform as possible a press nip between the backing roll and at least one additional roll which is without sag control, the circumference of the roll shell of the backing roll decreases axially towards its ends, i.e., that roll may be crowned. In addition, the backing roll may have its own roll shell support elements which are either in the press plane or are inclined slightly out of the press plane and/or the hydraulic pressure fluid supplied to the press roll and to the backing roll is adapted to supply a greater pressing force by the press roll. Optionally, a fourth press roll may form a nip with the additional roll. A felt passes through each nip.

Three roll press

A roll press including at least two rolls forming a press nip for the treatment of a web of material. A press roll includes a very flexible roll shell which is rotatable around a stationary support. The roll shell is mounted by at least one support element on the support. The support element has a concave support surface which forms a wide press nip with the backing roll. This provides a roll press which, even in the case of a backing roll which is without sag control, defines a press nip which is very substantially uniform. This is achieved by having the outer circumference of the shell of the press roll change in dimension in the axial direction from the axial center of the roll towards the ends of the roll, i.e., the outer circumference may increase or decrease. The circumference of the backing roll may or may not correspondingly change in the axial direction.

Growing community of inventors

Friedrichshafen, Germany

Rainer Bentele