Valmet Paper Machinery Inc.

Ab Karlstads Mekaniska Werkstad

Carl Zotterman

Antti I Ilmarinen

Erik G Stenberg

Nils-Erik Safman

Douglas Wahren

Nils-Erik R Karlsson

In order to increase the life of a flexible jacket in a shoe type press roll having a flexible jacket (11), end wall displacing element (28) and jacket stretching element (27), the end wall displacing element (28) are designed to permit a setting of an arbitrary operating position for one roll end wall (18) between two end positions on one of the two stub shafts (13) of the roll, and the jacket stretching element (27) are designed to maintain the stretching force substantially constant, whereby the other roll end wall (22) will be self-positioning and will automatically follow each axial displacment of said one roll end wall (18). Consequently, it will be possible to let the end walls (18, 22) be placed in one end position during a first period of operation and to displace them, for each subsequent period of operation, an adequate distance towards the other end position, whereby the fatigue and the wear of the roll jacket (11), which occur primarily at the axial end of the press shoe (14), will be spread over an area corresponding to the entire displacement distance between the end positions.

Press roll with displaceable end walls to reduce press jacket wear

Methods and apparatus for producing a web by injecting a jet of stock between two tensioned wires and running the wires over a circumferentially grooved forming cylinder. The cylinder grooves and a zone immediately on the other side of the wires extending from the forming throat where the web is injected to the web run-off point are in direct, open communication with the ambient atmosphere so that water is drained inwardly and outwardly of the forming cylinder as the web is being formed. The jet stock size, wire speed and wire tension are adjusted in relation to the radius of the forming cylinder so that the inward and outward drainage of liquid from the web occurs in relative amounts sufficient to avoid substantial two-sidedness of the web thus produced.

Two-sided drainage in a roll-type twin-wire former

Growing community of inventors

Hammaro, Sweden

Carl Zotterman