In English

Thermal Conductivity and Heat Capacity of Black Liquor in a Research Evaporator

Robert Strube
Göteborg : Chalmers tekniska högskola, 2006.
[Examensarbete på avancerad nivå]

Energy-efficient evaporation of black liquor generated in the chemical pulping process is becoming increasingly important from an economic and ecological point of view. The valuable cooking chemicals have to be regained, and the energy content of the organic constituents is used. This requires the water to be removed from the black liquor. This work aims at describing different methods for the measurement of the thermophysical parameters thermal conductivity and heat capacity. Knowledge of their behaviour and of their dependence on other parameters is necessary for an energy-efficient evaporation. Experiments were carried out on a research evaporator, built in cooperation between Kvaerner Pulping AB, Göteborg and Chalmers University of Technology. The aim was here to evaluate a method for on-line measurement of heat capacity of black liquor, involving the circulation pump of the evaporator. This method included modelling of the heat transfer in this pump in order to determine the heat capacity. The investigated temperature range was 30-110 °C and the range of black liquor solids content was 0-47 %. The results indicate that on-line measurement of heat capacity is possible in an evaporator, but more experiments have to be carried out to assure sufficient statistics. Moreover, the experiments should be extended to higher solids contents to prove the applicability of the devised method for an extended range.



Publikationen registrerades 2007-12-20. Den ändrades senast 2013-04-04

CPL ID: 63660

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