CFD-Based Modeling of Kraft Char Beds • Part 2: A Study on the Effects of Droplet Size and Bed Shape on Bed Processes
Source abstract
Abstract
This is the second of two papers. The first paper presented the char bed burning model used in this work. In this paper, the effects of liquor droplet size and bed shape on kraft char bed processes and lower furnace combustion are studied using a computational fluid dynamics (CFD)-based furnace model. The simulations show that droplet size affects not only the amount of in-flight conversion and the amount of combustible material reaching the bed, but also to what degree char carbon conversion in the char bed is due to direct oxidation or gasification. Droplet size also affects char bed burning indirectly through bed shape. Char bed shape affects the degree to which combustion air jets impinge on the bed surface, increasing carbon conversion by direct oxidation. In addition, changes in bed shape over time affect char bed processes. The results suggest that when a char bed starts to grow, the local carbon input to the bed could increase with bed height. In addition, carbon conversion decreases in locations of air jet impingement if the bed shape is not maintained.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Combustion and flame dynamics · Thermochemical Biomass Conversion Processes · Radiative Heat Transfer Studies
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (15)
Show source-provided references
1. Sutinen, J., Karvinen, R., and Frederick, W.J., Ind. Eng. Chem. Res. 41(6): 1477(2002).10.1021/ie000393a ↗
2. Jones, A.K., “A model of the kraft recovery furnace,” Ph.D. thesis, The Institute of Paper Chemistry, Appleton, Wisconsin, USA, January 1989.
3. Sumnicht, D.A., “A computer model of a kraft char bed,” Ph.D. thesis, Institute of Paper Chemistry, Appleton, January 1989.
4. Yang, W., Horton, R.R., and Adams, T.N., “Predictions of the gas flow pattern and mass transfer to a char bed in a recovery boiler using computational fluid dynamics,” Proceedings of the 1994 TAPPI Engineering Conference, TAPPI PRESS, Atlanta, Georgia, USA.
5. Wessel, R.A, Parker, K.L., and Verrill, C.L., TAPPI J. 80(10): 207(1997).
6. Ohran, B.J., Choi, M.M., Kaer, S., et al., International Chemical Recovery Conference and 11th International Symposium on Corrosion in the Pulp and Paper Industry, TAPPI PRESS, Atlanta, 2004, pp. 686-697.
7. Saviharju, K., Pakarinen, L., Kyttälä, J., et al., “Modeling and feedback measurements give new understanding about recovery boiler behavior,” 7th International Colloquium on Black Liquor Combustion and Gasification, University of Jyväskylä, Finland, 2006.
8. Saviharju, K., Pakarinen, L., Kyttälä, J., et al., “Three dimensional char bed imaging for numerical simulation feedback,” Proceedings of the 2007 International Chemical Recovery Conference, TAPPI PRESS, Atlanta.
9. Fan, Y., Yuan, J., and Salcudean, M., Proceedings of the TAPPI 2007 International Chemical Recovery Conference, TAPPI PRESS, Atlanta, p. 413.
10. Mueller, C., Eklund, K., Forssén, M., et al., Proceedings of the TAPPI 2004 International Chemical Recovery Conference, TAPPI PRESS, Atlanta, p. 979.
11. Bergroth, N., Engblom, M., Mueller, C., et al., TAPPI J. pp. 6-13 (2010).10.32964/TJ9.2.6 ↗
12. Engblom, M., Mueller, C., Brink, A., et al., TAPPI J. 7(10): 12(2008).10.32964/TJ7.10.12 ↗
13. Mueller, C., Brink, A., Hupa, M., 2005 Proceedings of the 18th International Conference on Fluidized Bed Combustion, American Society of Mechanical Engineers, New York, New York, USA, pp. 771-781.
14. Jones, W.P. and Lindstedt, R.P., Combust. Flame, 73: 233(1988).10.1016/0010-2180(88)90021-1 ↗
15. Frederick, W.J. and Hupa, M., Steady-state kraft char bed model, Report 91-9, Combustion Chemistry Research Group, Åbo Akademi University, Finland, 1991.