Numerical Investigation of Kraft Recovery Furnace Wall Temperature

Deposits can affect the in-furnace wall surface temperature in a Kraft recovery furnace. In CFD (Computational Fluid Dynamics) models of the Kraft recovery furnace, the wall surface temperature is frequently used as the heat-transfer boundary condition. Therefore, the effect of deposits must be taken into account in CFD models. In this work, CFD simulations of a Kraft recovery furnace were performed. Three approaches were used to provide the wall surface temperature as the heat-transfer boundary condition for the CFD model: A) a char-bed burning model was applied to the wall, and the surface temperature was calculated; B) the “radical deformation temperature” T70 was used as the surface temperature; C) a slagging wall model was used, and the surface temperature was calculated. These three approaches emphasize different aspects of Kraft recovery furnace deposits. In particular, implementation of the stand-alone slagging wall model as part of a furnace model has been accomplished in this research. The in-furnace wall surface temperature and the radiative heat fluxes to the wall from the CFD simulations have been analyzed and evaluated using measurements made in the Kraft recovery furnace. BINGZHI LI*, MARKUS ENGBLOM, DANIEL LINDBERG, ANDERS BRINK, MIKKO HUPA, RALF KOSCHACK, CHRISTIAN MUELLER NUMERICAL INVESTIGATION OF KRAFT RECOVERY FURNACE WALL TEMPERATURE