Drying section of papermaking plant with heated cylinder contacting one side of web, includes additional heating on opposite side, to minimize product curling tendency

摘要

The side of the web (1) not contacting the drying cylinder (3), is additionally blown with hot air and/or exposed to infra red radiation. During this additional heating, the web wraps a large cylinder (5). This is heated and applies suction. The diameter of the large cylinder (5) exceeds that of the adjacent drying cylinder (3), being 1.8-5 m. In the drying section, the web is carried on an endless recirculating drying screen (2). Its path alternates between the heated drying cylinder and guide rollers (4). The web is transferred from the drying screen to the large cylinder. During transfer, the screen partially wraps the large cylinder. Further stages of handling, transfer and drying are provided. Nozzle moistening and/or steam boxes may be included in the process train, to further control the curling tendency of the web.