Hello,
I am working in the domain of pyrometallurgy and wanted to get the opinion of a chemical engineer on the following problem.
I am modeling a zinc fuming process for the reduction and evaporation of zinc from a molten slag bath at 1350 °C. In this slag bath, hot blast air and CH4 are injected at the bottom of the furnace (diameter of the furnace = 3 meter, heigth = 5 meter). The injection of hot blast air and CH4 in the bath causes reduction reactions mainly of ZnO_slag to Zn(g). This injection of blast air a is very turbulent process and causes substantial mixing and splashing of the slag bath. An schematic representation of the furnace can be found in Figure 1 on the following link:
The particular problem for me is that the sidewalls of this furnace are not protected by refractory, but are water-cooled. Important is to estimate the heat transfer coefficient from the bath to the vertical sidewalls. My question is if there exist any correlations to estimate the heat transfer coefficient of the bath to the vertical sidewalls, preferrably as a function of Re, Pr, and the macroscopic process variables (bath height, bath diameter, rate of blast air injection etc.)
I have looked everywhere to find appropriate correlations for this, but I couldn't find anything useful. (e.g. there are many papers on the heat transfer from the bubbles to the bath, or on the hydrodynamic aspects of this kind of flow, but so far nothing on heat transfer from the bath to the vertical sidewalls.) The closest literature I found was on steel making ladles, however this is not very applicble to my problem since I work with a liquid slag bath instead of a liquid steel bath.
Is there anybody who has experience in this area or who may be able to me an indication how to tackle this problem please?
Thanks in advance!
Karel
I am working in the domain of pyrometallurgy and wanted to get the opinion of a chemical engineer on the following problem.
I am modeling a zinc fuming process for the reduction and evaporation of zinc from a molten slag bath at 1350 °C. In this slag bath, hot blast air and CH4 are injected at the bottom of the furnace (diameter of the furnace = 3 meter, heigth = 5 meter). The injection of hot blast air and CH4 in the bath causes reduction reactions mainly of ZnO_slag to Zn(g). This injection of blast air a is very turbulent process and causes substantial mixing and splashing of the slag bath. An schematic representation of the furnace can be found in Figure 1 on the following link:
The particular problem for me is that the sidewalls of this furnace are not protected by refractory, but are water-cooled. Important is to estimate the heat transfer coefficient from the bath to the vertical sidewalls. My question is if there exist any correlations to estimate the heat transfer coefficient of the bath to the vertical sidewalls, preferrably as a function of Re, Pr, and the macroscopic process variables (bath height, bath diameter, rate of blast air injection etc.)
I have looked everywhere to find appropriate correlations for this, but I couldn't find anything useful. (e.g. there are many papers on the heat transfer from the bubbles to the bath, or on the hydrodynamic aspects of this kind of flow, but so far nothing on heat transfer from the bath to the vertical sidewalls.) The closest literature I found was on steel making ladles, however this is not very applicble to my problem since I work with a liquid slag bath instead of a liquid steel bath.
Is there anybody who has experience in this area or who may be able to me an indication how to tackle this problem please?
Thanks in advance!
Karel
