Steam Supply & Heat Transfer

Saturated steam is continuously fed into the hollow dryer cylinder. The steam condenses on the inner wall of the cylinder, releasing a large amount of latent heat that heats the cylinder’s outer surface to a stable temperature (typically 100–130°C, adjustable based on paper type).

Web Drying Process

The wet paper web (with a dryness of 30%–40% after pressing) is tightly wrapped around the heated dryer cylinder surface by guide rolls and press felts. Heat is transferred from the cylinder surface to the paper web, evaporating the remaining free water and capillary water in the pulp fibers.

Moisture & Condensate Removal

The water vapor evaporated from the paper web is discharged by the dryer section’s exhaust system. Meanwhile, the condensed water formed inside the cylinder is removed by a siphon device to avoid affecting the heat transfer efficiency of the cylinder wall.

Continuous Drying & Quality Control

In actual production, multiple dryer cylinders are arranged in a group (dryer group). The paper web passes through the cylinders in sequence to achieve gradual drying, with its dryness increased to 90%–95% (meeting the finished paper standard). The rotational speed of the dryer cylinders is synchronized with the whole paper machine to ensure uniform drying and prevent paper web shrinkage or deformation.