Thermodynamic and Heat Transfer Evaluation of Pocket Drying Section in the Multi-Cylinder Dryers of Paper Machine

Document Type: Full article

Authors

Chemical Engineering Faculty, Sahand University of Technology, Tabriz, Iran

Abstract

In this study a developed model has been used to evaluate the paper drying process and examine the pocket dryer conditions of a multi-cylinder fluting paper machine. The model has been developed based on the mass and energy balance relationships in which the heat of sorption and its variations with paper temperature and humidity changes have been taken into account. The applied model can be used to compute the drying parameters and analyze the pocket drying conditions. Furthermore, the effects of web tension on the heat transfer have been investigated. In the available operating range of the web tension, the overall mean heat transfer coefficient will be within 300-550 W/m2.K. The pocket air temperature was between 50 and 90 oC. The dew point temperature wasn’t close to the pocket air temperature and dew drop never happened during the dryer section. Based on the modeling result and using a novel technique, the maximum level for the exhaust air in the studied machine can be estimated to be 0.2 kg H2O/kg dry air. Result shows that increasing the exhaust humidity to the optimal level will lead to 4% reduction in the required energy and 20% rise in the heat recovery potential. Accordingly the specific heat consumption per evaporated water for the studied drying section can be reduced from 3.96 to 3.81 GJ per ton water.

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Main Subjects


[1]   Etemoglu, A. B. Can, M. Avc, A. and Pulat, E., "Theoretical study of combined heat and mass transfer process during paper drying", Heat and Mass Trans., 41 (5), 419 (2005).

[2]   Goran, G. J. Tanacic, N. D. Stamenic, M. S. and Adzic, V. M., "Waste Heat Potentials in the Drying Sction of the Paper Machine in UMKA Cardboard Mill", Thermal Sci., 15 (3), 735 (2011).

[3]   Lang, I., "Dryer Fabrics and Energy Consumption in the Drying Section", TAPPI Paper Con09 Conf., St. Louis, MO (2009).

[4]   Laurijssen, J. De Gram, F. J. Worrell, E., and Faaij, A., "Optimizing the Energy Efficiency of Conventional Multi-Cylinder Dryers in the Paper Industry", Energy, 35 (9), 3738 (2010).

[5]   Roonprasang, K., Thermal Analysis of Multi-Cylinder Drying Section with variant Geometry, Ph.D., Thesis Dissertation, in Depatment of Processing Machine and Processing Tech., Technical University of Dresden (December 2008).

[6]   Chavan, P. A. Shinde, B. S. Bhagwat, V. N. Shinde, P. P. and Patil, B. D., "Pocket Ventilation System In Dryer Section Of Paper Machine: A Review", Int. J. Tech. Enhanc. Emerg. Eng. Res., 3 (3), 11 (2015).

[7]   Ghosh, A. K., Fundamentals of Paper Drying – Theory and Application from Industrial Perspective. Principal, AKG Process Consulting, 33 McFarlane Court, Highett, Australia, (2009).

[8]   Kong, L. and Liu, H., "A Static Energy Model of Conventional Paper Drying for Multicylinder Paper Machines", Drying Tech., 30 (3), 276, (2011).

[9]   Nissan, A. H. and George, H. H., "Heat and Mass Transfer Transients in Cylinder Drying, Part II: Felted Cylinders", A.I.Ch.E. J., 7 (4), 635 (1961).

[10]  Nissan, A. H. and Hansen, D., "Heat and Mass Transfer Transients in Cylinder Drying, Part I: Unfelted Cylinders", A.I.Ch.E. J., 6 (4), 606 (1960).

[11]  Wilhelmsson, B., An Experimental and Theoretical Study of Multi-Cylinder Paper Drying, Doctoral Dissertation, in Department of Chem. Eng., Lund University, Sweden (1995).

[12]  Wilhelmsson, B. Nilson, L. Stenstram, S. and Wimmerstedt, R., "Simulation Models of Multi-Cylinder Paper Drying", Drying Tech., 11 (6), 1177 (1993).

[13]  Wilhelmsson, B. and Stenstram, S., "Experimental and Computational Evaluation of Mass Transfer Resistance of Paper Dryer Fabrics", Nordic Pulp and Paper Res. J., (2), 174 (1995).

[14]  Wilhelmsson, B. and Stenstrom, S., "Heat and Mass Transfer Coefficients in Computer Simulation of Paper Drying", Drying Tech., 13 (4), 959 (1995).

[15]  Karlsson, M. and Stenström, S., "Static and Dynamic Modeling of Cardboard Drying Part1: Theoretical Model", Drying Tech., 23 (1-2), 143 (2005).

[16]  Karlsson, M. and Stenström. S., "Comparison of Two Modeling Approaches for a Multi-Cylinder Paper Dryer", Drying 2004 – Proceedings of the 14th Int. Drying Symposium, São Paulo, Brazil, p. 422 (2004).

[17]  Karlsson, M. and Stenström, S., "Static and Dynamic Modeling of Cardboard Drying Part 2: Simulations and Experimental Results", Drying Tech., 23 (1-2), 165 (2005).

[18]  Yeo, Y. K. Hwang, K. S. Yi, S. C. and Kang, H., "Modeling of the Drying Process in Paper Plants", Korean J. Chem. Eng., 21 (4), 761 (2004).

[19]  Berrada, M. Elkadri, N. E. Rebaine, A. and Elkadri, M., "Physical Model for Condensation Steam in Paper Dryers Numerical Solutions Obtained by Finite Element Method", TAPPI Eng. Conf. Proceedings (1998).

[20]  Berrada, M. Tarasiewicz, S. Elkadiri, M. E. and Radziszewski, P. H., "A State Model for the Drying Paper in the Paper Product Industry", IEEE Trans. on Indus. Elec., 44 (4), 579 (1997).

[21]  Berrada, M. Tarasiewicz, S. and Richard, M. J., "A Computer Model for the Drying Paper in the Paper Product Industry", Proc. Modeling and Simulation Conf., Pittsburgh, PA, p. 2175 (1992).

[22]  Sivill, L. Ahtila, P. and Taimisto, M., "Thermodynamic Simulation of Dryer Section Heat Recovery in Paper Machines", App. Thermal. Eng., 25 (8–9), 1273 (2005).

[23]  Chen, X. Li, J. Liu, H. Yin, Y. Hong, M. and Zeng, Z., "Energy System Diagnosis of Paper-Drying Process: Part 1. Energy Performance Assessment", Drying Tech., DOI: 10.1080/07373937.2015.1087022 (2015).

[24]  Ghodbanan, S. Alizadeh, R. and Shafiei, S., "Steady-State Modeling of Multi-Cylinder Dryers in a Corrugating Paper Machine", Drying Tech., 33 (12), 1474 (2015).

[25]  Åkesson, J. and Slätteke, O., A Modelica Library for Paper Machine Dryer Section Modeling – DryLib –and applications, Internal Report, in Department of Automatic Control, Lund University, Sweden (2006).

[26]  Gaillemard, C., Modelling the Moisture Content of Multi-Ply Paperboard in the Paper Machine Drying Section, Licentiate Thesis, in Departement of Mathematics, Stockholm, Sweden (2006).

[27]  Perrault, R. D., Operation of the Dryer Section, Practical Aspects of Pressing & Drying Short Course, TAPPI Press, Atlanta (1998).

[28]  Pikulik, I. and N. A. Poirier, New Developement in Paper and Board Drying, Keynote Lecture, Paprican,Pointe-Claire, Quebec,
(2003).

[29]  Reardon, S. A., A Mathematical Model for The Simulation of Paper Drying Energy Consumption, Ph.D., Thesis Dissertation, in Department of Civil and Mech. Eng., University of Tasmania (1994).

[30]  Karlsson, M., Papermaking Science and Technology, In: Book 9: Papermaking Part 2, Drying, Helsinki, Finland, Fapet Oy. (2000).

[31]  Rissanen, E., Technical Report of Testing and Analyzing, Machine Analysis-Process Ventilation Survey, Mazandaran Wood & Paper Industries PM2, Metso Paper (2008).

[32]  Shrivastava, N. Jordan, J. and Fischer, T., Technical Report of Dry Section Paper Machine Analysis, Mazandaran Wood & Paper Industries PM2, Heimbach GmbH & Co. KG. (2014).