Machine dewatering fibrous web in papermaking plant, includes housing raising web temperature and reducing viscosity, to assist dewatering by pressing

摘要

A heater (14, 15) located in the casing (6), raises the temperature of the fibrous web (5). The heater extends over a dewatering zone, just before it, over an entire sieve or felt section, or over the entire pressing section. The casing has thermally-insulated walls (9). A fluid, especially air, carries heat, transferring it to the web. Connections are provided for supply and return of the air. Air is directed onto the web through a steam heater box (17) to cause local increase in temperature. The casing is located close to the web, just above or below it. It includes infra-red radiators. The casing has a supply of flushing water with a full-width distribution pipe, to clean its walls on the side facing the web. This water is passed through a heat exchanger to recover heat. Its pipework is thermally-insulated. Further equipment details are provided in accordance with the foregoing.