Method for impingement drying and/or through-drying of a paper or material web

Abstract

A method and apparatus for impingement drying and/or through-drying of a paper or material web in which the web is dried by blowing hot air and/or superheated steam and/or equivalent from an impingement drying device in a direction substantially perpendicular to the web, and the web is passed on support of a wire or equivalent past the impingement drying device. In the area of the impingement drying device, the web and wire are supported from the opposite side of the wire, opposite in relation to the web, by blowings produced from vacuum blow box substantially across the entire width of the web. One set of blowings from the blow box are blown at a speed substantially higher than the speed of the drying wire. The outlet direction of the blowings is substantially the same as the running direction of the drying wire in this area, and as such, steam and/or air is/are ejected out of the space between the drying wire and the wall placed in connection with the blow boxes that produce the blowings. A second set of blowings from the blow boxes are blown in the direction opposite to the running direction of the wire so as to seal the area of vacuum between the wire and the blow box. Substantially the same medium may be used as the blow medium in the blow box as is used in the impingement drying device.

Dependencies are inferred from the claim text.