Influence of Hot Metal Flow on the Heat Transfer in a Blast Furnace Hearth
1985 Volume 71 Issue 1 Pages 34-40
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1985 Volume 71 Issue 1 Pages 34-40
The influence of hot metal flow on the heat transfer in a blast furnace hearth was studied by the flow calculation, the water model experiment and the investigation of wear profiles of dissected hearth.
The hearth flow can be classified into the one in a uniformly packed hearth of coke with good permeability and the one in a hearth having a coke free space at the bottom part of it. The result of water model experiment shows that the heat transfer of the former is similar to that of the cyrindrical packed bed, and that of the latter the laminar flow within parallel plates.
By virtue of these similarities, the heat conductance of a packed hearth can be expressed as the function of the dimension of hearth, the flow rate as well as the thermal properties of fluid. The heat conductance of real furnaces can be shown as
h=(14.2/d)+(6.3/D+1.7/d2)(Q/D),
where h is the heat conductance (kcal/m2 h°C), d is the depth of iron pool (m), D is the diameter of hearth (m) and Q is the tapping rate (t/h).
The wear level at the bottom part of carbon hearth can be calculated from h thus obtained. Good agreement has been confirmed between the calculated wear level and the observed ones at dissected hearths.
