Process control and automation
- Introduction to process control and automation
- Development of process automation
- Fibre process automation
- Chemical recovery as a control object
- Advances in paper machine automation
- Paper machine as a dynamical system
- Tasks in paper machine control and management
- Control of stock flow concentration and quality
- Machine direction control
- Cross-directional control – The static optimisation
- Cross-directional control – Dynamics
- Cross-directional control – further aspects
- Controlling functional paper properties
- Managing grade chances in the paper machine
- Managing disturbances caused by broke and recovered solids
- Millwide systems
- Modelling and control methods
Black liquor evaporation – Fouling The evaporation plant usually consists of multiple evaporator units connected in series (Figure 1). Only the evaporator with the highest solids concentration uses fresh steam. Liquor boils there and the liquor vapour proceeds to the next stage as heating steam. This continues until the steam condensate leaves the last stage.
Authors & references
Authors:
Professor Emeritus Kauko Leiviskä, University of Oulu
References:
- Clay, D. T. (2010). Evaporator principles and black liquor properties. 2010 TAPPI Kraft recovery course. 3.1. Florida, USA, TAPPI.
- Andersson, M. 2015. Modelling of Black Liquor Evaporator Cleaning. Master’s Thesis in Chalmers University of Technology, Göteborg, Sweden.
- Frederick, j., Shi, B., Euhus, D.D. and Rousseau, R.W. 2004. Crystallization and control of sodium salt scales in black liquor concentrators. Tappi Journal, 3(6):7–13.
- Shi, B. and Rousseau, R. W. 2003. Structure of burkeite and a new crystalline species obtained from solutions of sodium carbonate and sodium sulfate, J. Phys. Chem. B (107):6932-6937.
- Gourdon, M. 2011. The effects of flow velocity on crystallization fouling in falling film black liquor evaporators. International Conference on Heat Exchanger Fouling and Cleaning. Crete Island, Greece, June 5.10.
- Karlsson, E. Gourdon, M., Olausson, L. and Vamling, L. 2013. Heat transfer for falling film evaporation of black liquor up to very high Prandtl numbers. International Journal of Heat and Mass Transfer 65:907–918.
- Costa, G.A-A., de Oliveira, E.D., Park, S.W. and Cardoso, M. 2007. Overall heat transfer coefficients in a kraft black liquor industrial evaporation unit. Part II – Predictive correlations. Appita Journal 60(4):327-332.
- Kandiklar, S. G. 1990. A general correlation for saturated two-phase flow boiling heat transfer inside horizontal and vertical tubes. Journal of Heat Transfer 112(2):219-228.
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This page has been updated 25.11.2020