Research On Modeling Of Paper Sheet Drying

The dryer section is the main energy consumer of a paper machine，and its reasonabledesign and operation have a significant impact for enterprises to reduce energy consumptionand production costs. Ascertaining the mechanism of the paper sheet drying process is theprecondition of reasonable design and operation，so the study on paper sheet drying processis of importance.Multi-cylinder drying and Yankee drying are still the widest method in the paper sheetdrying. In this paper，simulations of paper sheet drying process in multi-cylinder and Yankeedryer section are done, combining with the actual situation of the production sites. Maincontents are as follows:(1) The model of steam and condensate system in multi-cylinder drying section is builtand relevant parameters are determined according to the analysis.The practical model, whoseobject is steam and condensate system of newspaper machine, is established and solved.Comparison with the calculated and design values shows that the model is in line with theactual situation.(2) The model of the paper sheet drying in multi-cylinder drying section is built withmodule method，according to laws of conservation of mass and energy，combining with thestructure of multi-cylinder drying section. The relevant parameters of the model aredetermined by laws of heat and mass transfer and analysis of physical properties of hood air.On the basis, the practical model，whose object is the corrugated paper sheet dryingprocess in a multi-cylinder dryer section，is established by measuring the cylinder surfacetemperature and ambient air temperature and humidity，and solved with the help of ode45function of Matlab. Comparison with the simulation and practical situation shows that，themodel is suitable for the simulation of paper sheet drying process in the multi-cylinder dryersection.(3) The model of the tissue sheet drying in Yankee drying section is established，according to laws of conservation of mass and energy，combining with the structure ofYankee drying section. The relevant parameters of the model，including the heat transfercoefficient between ambient air and tissue，are determined according to laws of heat andmass transfer and analysis of physical properties of hood air.On the basis, the practical model is built， whose object is the tissue sheet drying process in Yankee dryer section of a BF-12tissue paper machine，and solved with the helpof ode45function of Matlab. Comparison with the simulation and practical situation showsthat，the model is fit for the simulation of tissue sheet drying process in the Yankee dryersection.