摘要 |
A method and apparatus effect drying of a paper web using a plurality of heated drying cylinders and at least one air impingement module having a hood. The paper web is brought into operative contact with the heated drying cylinders, and at least one of the final moisture content, quality, and cross-direction profile of the paper web is regulated. The regulation is effected by adjusting the efficiency of air impingement drying of the paper web, by adjusting at least one of the blowing velocity of the medium (typically air) blown against the paper web, the humidity of the blowing medium, and the distance of the hood of the impingement module from the paper web. At least one of the final moisture content of the paper web and its quality may also be regulated by adjusting the steam pressure of one or more drying cylinder groups. Typically the final moisture content of the web is measured after the last drying cylinder group and the efficiency of air impingement drying is regulated on the basis of that measurement. |