A. Ahlstrom Corporation

A. Ahlstrom Osakeyhtio

Valmet-ahlstrom Inc.

Osmo Evalahti

Tapio Waris

Jukka Antikainen

The present invention relates to an apparatus for guiding the wires of a paper machine former. The former includes a double wire section including two wires (1,2) in parallel direction (R) in which on the other side of the wires (1,2) a dewatering unit (10) is arranged to drain water from the stock (3) flowing between the wires and in which at least the farthest wire (2) from the dewatering unit is compressed with foil lists (20) or equivalent support members against the wire (1) nearest to the dewatering unit (10) in cross-machine direction with respect to wire direction (R) and across the web width. The load of these foil lists (20) is achieved by separate pressurized load hose construction (21) arranged between each foil list (20) and support table or equivalent in order to achieve the desired press to the stock (3) between the wires (1,2). Each load hose construction (21) is, according to the invention, equipped with separate pressure spaces into which a desired overpressure can individually be conducted to achieve a desired foil list load against the wire leaning against the said foil list across the web width.

Apparatus for guiding wires of a double wire former

A paper machine head box includes perforated plates being used as a distributor and a turbulence generator and having flow ducts, of which the ones at the edges are of different size than the remaining flow ducts. According to a preferred embodiment, slides, which are movable sideways, are provided at the ends of slice ducts at both edges of the perforated plates in order to regulate the flow. The slides and the perforated plates define the outermost flow ducts of the turbulence generator and the distributor.

Paper machine head box with adjustable perforated plate flow ducts

A system for damping the pressure fluctuations in a paper machine headbox. The headbox applying the damping system comprises an equalizing chamber communicating with an air space, this equalizing chamber having an outlet/outlets for a channel/channels leading to the equalizing chamber as well as an inlet/inlets for a channel/channels leaving the equalizing chamber. The outlet chamber is disposed with regard to the inlet channel so, and the cross surfaces of the outlet and inlet channels have been dimensioned so that the jet of stock flowing out of the outlet and expanding divergently falls substantially inside the boundaries of the inlet.

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Karhula, Finland

Osmo Evalahti