Voith Sulzer Papiermaschinen Gmbh

Rudolf Hasenfuss

Christian Schiel

Joachim Grabscheid

Wolfgang Schuwerk

A press device for draining and/or smoothing, or shaping the surface and controlling the sheet structure of fibrous pulp webs with a surface weight of under 100 g/m,, such as the fibrous pulp webs used to make graphic papers. The device has a press area which includes at least one press nip through which, during operation, the fibrous pulp web is fed at a velocity of at least 1200 m/min, under simultaneous impingement by pressure. The press area includes at least two press zones subsequent to one another. The device is further characterized by a K value of at least 2.5 kPa&middot;s&middot;m. This K value is the product of L,and I,. L,is the length of the first press zone, measured along the direction in which the web runs, and I,is the total press impulse operating on the fibrous pulp web in the entire press area.

Process for draining or smoothing a fibrous pulp web

Shoe press unit and method for treatment of a fibrous pulp web. The shoe press unit includes at least one press shoe, an opposing surface, a flexible press belt guided over the press shoe, and at least one force element composed of a cylinder/piston unit supported on a carrier. The at least one force element presses the press belt against the opposing surface to form a press zone elongated in a web run direction, and the cylinder/piston unit include a pressure chamber having at least one pair of cylinder/piston subunits successively positioned in the web run direction. Pressure fluid lines are coupled to respective ones of the at least one pair of cylinder/piston subunits to separately supply pressure fluid to each cylinder/pressure subunit to impart a tilting moment long a tilt axis substantially perpendicular to the web run direction. The method includes supplying a pressure fluid to a first and second pressure fluid line from a common pressure fluid source at a source pressure, supplying pressure fluid through the first pressure fluid line at a first fluid pressure to a first subunit of the at least one pair of cylinder piston subunits, supplying pressure fluid through the second pressure fluid at a second fluid pressure to a second subunit of the at least one pair of cylinder piston subunits, and maintaining a sum of the first and second fluid pressures to be substantially equal to the source pressure.

Shoe press unit

A press arrangement of a paper or cardboard machine for the treatment of a fibrous pulp sheet in a press opening that is extended in the run direction of the fibrous pulp sheet. The press opening is defined by two press surfaces, at least one of which is constructed of a flexible press sleeve that is guided over at least one press shoe. The flexible press sleeve is further able to press against the opposing press surface with the aid of the press shoe due to the creation of a fluid cushion between the press shoe and the press sleeve. The press shoe is thus able to be tensioned such that a resulting main press force is exerted in a direction that runs substantially perpendicular to the fibrous pulp sheet being guided through the press opening. A lever is designed to load the press shoe with an positive or negative force that acts on the press shoe substantially perpendicular to the resulting main press force. The additional positive or negative forces transfer a tilting moment to the press shoe whereby the press shoe tilts around a respective tilting axis. The tilting axis extends substantially perpendicular to the run direction of the fibrous pulp sheet and in the transverse direction of the press arrangement. Thus, the additional forces can, substantially, independently influence the pressure profile in the press opening, set along the run direction of the fibrous pulp sheet.

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Herbrechtingen, Germany

Rudolf Hasenfuss