Sulzer-escher Wyss Limited

Jorg Walter

Alfred Bubik

Otto Hildebrand

Karl Muller

Hans K Dahl

In order to regulate dewatering of the fiber suspension and the formation of the paper web between the upper and lower wires of the papermaking machines, upper ledges are provided along with the upper wire. These upper ledges are particularly constructed so as to have uniform design. Between these upper ledges, there is left free the same distance or spacing. This distance is not smaller than the width of each upper ledge. The individual distances between the upper ledges can be closed by insertable inserts so that the dewatering can be forcibly accomplished at mutually separated zones. Along the lower wire, there are provided lower ledges at a table, and between these lower ledges, it can be adjusted varying distances or spacing therebetween. The mutual distance or spacing between the lower ledges, according to a favorable construction, is always greater than the width of the individual upper ledges plus the distance or spacing of an upper ledge from the next neighboring upper ledge. The lower ledges can be mounted at the table so as to be lengthwise displaceably and individually adjustable in the direction of the lower wire. The table can be selectably positioned vertically as well as horizontally relative to the lower wire. All of these measures also can be accomplished during operation of the papermaking machine. The individual lower ledges are elastically supported against the table and this table is elastically supported against its foundation. It is possible to undertake the web forming operation, during operation of the papermaking machines, in accordance with technological requirements and the time wise as well as localized situations, while protecting the paper web which is to be formed and equally the equipment which is to be operated.

Method of using a forming section of a papermaking machine

A twin wire former wherein the forming turbulence of a first forming section is quieted by a main forming roller. Behind the main forming roller, as viewed with respect to a predetermined direction of travel of the forming wires, there is accomplished a further forming of the paper web or sheet from the fiber stock suspension in a second forming section. Due to this arrangement there is possible optimum formation of the paper web or sheet with the use of very little dilution water for the fiber stock suspension. Additionally, due to intensive shear forces present in the second forming section flocks formed in the fiber stock suspension and the paper web or sheet at the region of the main forming roller, can be eliminated so that the structure of the paper web or sheet is made more uniform.

Twin wire former

The de-watering apparatus for a two-wire paper machine is constructed in such a manner that following the convergence of both wires, firstly, a uniform pressure at a forming roll is exerted on the suspension layer located between the wires. Subsequently, both wires pass de-watering rails which may be located in the upper and/or the lower wire. In this case, an under-pressure is exerted at least at the rails located in the upper wire. At least one further de-watering member then follows before both wires are separated again. The de-watering apparatus can also be used after a preliminary de-watering section, for example an endless wire, and also in the direct vicinity of a head box.

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Ravensburg, Germany

Jorg Walter