Aktiebolaget Svenska Flaktfabriken

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Flakt Aktiebolag

Ingemar Karlsson

Karl-Hugo Andersson

Claes Halldin

Rolf Petersson

Lars Nilsson

Rune Gustafsson

Rolf Akesson

Enar Ahlbert

Bengt Oldaeus

Percyval Svensson

Goran Svensson

Bengt Lindstrom

Axel Ydrefors

Eric Nelenius

Rolf Quick

Blow box for use in a plant for drying a material web

The invention relates to an arrangement in cylinder drying, intended for incorporation in a paper machine and including a plurality of heated cylinders (1) arranged substantially parallel in two rows, about which the paper web (2) is taken serpentine during drying, whereat it is carried by an endless porous fourdrinier wire (3) which presses the web against the cylinder surfaces in one row of cylinders and lies between the paper web and the cylinders in the other row. For preventing the web from lifting from the wire as a result of pressure differences on either side thereof, there are blowing boxes (11,12) arranged for blowing out air in at least some of the pockets (4,5) situated on opposite sides of the web, each of said pockets being formed by the web and three cylinders lying consecutively in the travelling direction of the web. Blowing out from the blowing boxes takes place in directions such that a sub-pressure is generated in the pockets (4) where the wire (3) lies outmost towards the pocket, and an excess pressure generated in the pockets (5) where the paper web (2) lies outmost towards the pocket.

Arrangement in cylinder dryer

The invention relates to a plant for drying a material web. Such plant includes a plurality of upper (3) and lower blow boxes arranged substantially mutually parallel and at right angles to the travelling direction of the web. The lower boxes are intended to support the web and are provided in their surfaces facing towards the web with orifices for blowing air in directions substantially parallel to the plane of the web. The air ejection velocity is thereby sufficient to maintain the web in a specified floating position above said boxes. The upper blow boxes (3) are situated on the other side of the material web and have orifices for blowing air substantially perpendicularly to the plane of the web. According to the invention, the distance (H) between the blowing orifices of the upper blow boxes and the web is variable. It is furthermore adjustable so that the relative energy requirement for the upper blow boxes may be brought closely into the region of the value 1. The variable distance (H) may be provided, in accordance with one embodiment of the invention, by the upper blow boxes (3) being at one end ( 6) pivotably mounted in a wall (7) of a compressed air chamber, while their other ends (8) are movable in height for adjusting the distance (H) to the underlying, fixed web-positioning blow box (4).

Drying plant for a material web

The invention relates to an arrangement for pulling the tail of a web-like material through a drying or cooling plant. In such a plant the web-like material is floated on air at a given distance from a surface provided with air delivery orifices. The web-like material (10) is thereby caused to pass zig-zag over drivable reversing rolls (2), while an endless traction or pulling member (3) in the form of a belt or rope runs in a separate path through the plant, substantially parallel to the material web, and is provided with means (12,13,14,15) with the aid of which the forward web end or tail (11) is attachable for pulling through the plant. At least one of the reversing rolls (2) is adapted at one end portion for carrying the tail pulling member either directly or over a pulley (9) drivably connected to said end portion. Driving the tail traction member is performed with the same means as drive the reversing rolls. The means (13) for fixing the tail (11) to the traction member (8) has a given stretching ability for preventing the material web (10) from rupturing.

Arrangement for pulling the tail of a web-like material through a drying

Web material is carried on air to advance the material in a fixed stable floating position through one or more decks of a treating plant, preferably a drier. The air is supplied through pairs of apertures arranged in the upper surface of blow-boxes distributed in the conveying path of the material which apertures eject the air in pairs of streams facing away from each other. To reduce deflection of the material between said pair of apertures the space between said apertures is supplied separately with a great volume of secondary air of the same static pressure as that prevailing on the upper surface of the material, which secondary air is taken along by ejector effect by the primary air streams ejected from the apertures of the blow-boxes.

Treating airborne web material

A treatment plant for web material which, when bent, exhibits stiffness transverse to the direction of bending. The treatment plant comprises a series of blow boxes arranged in sections with the boxes in each section having parallel plane perforated surfaces on opposite sides of the web path. The perforations are graduated in degree with a high degree of perforation on one side of the web path being opposed by a low degree of perforation on the other side of the web path, and vice versa, so that the web assumes a wave shape between the first and second planes, the wave staying with its nodes in definite positions closer to the one plane opposite the highly perforated group in the second plane and closer to the second plane opposite the highly perforated group in the one plane.

Arrangement for conveying web material through a treating plant

Web or sheet material is carried on air to advance the material in a fixed stable floating position through one or more decks of a treating plant, preferably a drier. Fixing chambers providing an air flow substantially parallel to the plane of the material and blow boxes with an air flow substantial perpendicular to said plane of the material are located adjacent each other on both sides of the material and are arranged to face each other mutually on the opposite sides of the plane of the material.

Dryer for material coated on two surfaces

Web or sheet material is carried on air to advance the material in a fixed stable floating position through one or more decks of a treating plant, preferably a drier. Spaced fixing chambers carried out with an air flow substantially parallel to the plane of material are mounted on either side of material and arranged to co-operate with blow boxes carried out for an air flow substantially perpendicular to said material plane, said blow boxes located partly on opposite sides of the material facing the fixing chambers, partly between said chambers.

Growing community of inventors

Vaxjo, Sweden

Ingemar Karlsson