Drying section and method in paper machine

Abstract

A multi-cylinder drying section and method in a paper machine wherein the paper web to be dried is guided into contact with the surfaces of heated drying cylinders wherein the drying fabric is cooled as it travels from one drying cylinder to the next. According to one embodiment, preferably used in the first group or groups of drying cylinders, a single-fabric draw is used wherein the web is supported on the drying fabric as it runs from the cylinders of one line to the cylinders of the other line so that the web is in direct contact with the surfaces of the drying cylinders in one line while the drying fabric is in direct contact with the surfaces of the cylinders in the other line. The drying fabric is cooled as it runs between the cylinders on which the web is in direct contact with the heated surfaces by causing the drying fabric to come into direct contact with a cooling roll or cylinder surface whose contact area is relatively large. In another embodiment wherein the web is conducted through the drying section in a twin-wire draw, i.e., wherein the web travels between the cylinders of the respective lines in an open draw, the drying fabrics come into direct contact with guide rolls which act as cooling members to cool the respective fabrics. The invention provides lower production costs and reduced energy consumption as well as improved machine reliability, a significantly reduced length of the drying section and increased service life of the drying fabrics.