Valmet Oy

Yngve Lindstrom

Pekka Eskelinen

Vesa Koponen

Jorma Kotanen

Timo Vedenpa

An air-directing device for directing air to the multiple cylinder dryer of a paper machine includes members for blowing dry air into the vicinity of the web at those points where the evaporation of water from the web is strongest. This reduces the humidity in such regions and promotes the evaporation of water from the web. The points are the initial parts of the cylinder intervals after contact with the web. The air-directing device is so placed, and its air-blowing members are so disposed and directed, that the air blown out from such members is directed into the clefts defined by the surface of the drying cylinder and the paper web. This achieves a pressure effect in the clefts. The air-blowing members are primarily used in connection with single fabric conduction in pockets on the side of the web to urge the web fast to the fabric and are preferably disposed on a doctor beam or in conjunction therewith.

Air-directing device for multiple cylinder dryer of paper machine

Nozzle apparatus of the over-pressure type for handling web material includes a nozzle box having a nozzle carrying surface which is curved towards the interior of the box to define a recess in the direction of web run and a pair of opposed nozzle slots located so that gas jets issuing therefrom follow the nozzle carrying surface in opposite directions with respect to each other so as to meet in the region of the curved recess to form a tranquilization zone. In this manner an air cushion is formed for the web which extends over a considerable distance in the direction of the web run to carry the web.

Nozzle apparatus for handling web material

Nozzle apparatus for airborne paper web dryers of the non-impingement or underpressure type including a blow box member defined by top web supporting and bottom wall portions and back and front wall portions. The front and top supporting wall portions are interconnected by a curved guide surface and an upwardly directed nozzle is provided on the front wall portion spaced below the entry edge plane of the guide surface. The relative values of the width of the nozzle gap and the radius of curvature of the curved guide surface are such that the gas flow exiting from the nozzle follows a portion of the guide surface and departs therefrom prior to the exit edge plane of the guide surface. The upper surface of the top supporting wall of the blow box defines a small angle with the running plane of the web.

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Turku, Finland

Yngve Lindstrom