The purpose of this study was to investigate fluid flows in the blast furna
ce trough and furthermore extend the lifespan of the trough. For that purpo
se both physical and mathematical models were utilised. The effect of diffe
rent flow controllers, both at the surface and at the bottom of the trough,
on the flow behaviour in the trough was examined. Additionally, the effect
of the height of the bath level on flow velocities was studied. Return flo
ws, caused by the tapping stream, are responsible for the wear of the walls
at the impact point. According to the model tests, the smaller the area of
turbulent flow, the stronger the flow in the vicinity of the walls appears
to be. Return flows can not totally be restrained by flow controllers. How
ever, the turbulence can be diminished with longitudinal pads at the bottom
of the trough. Bottom pads cause increasing bottom wear and reduction in t
he length of laminar area. Increasing the amount of consumable refractory m
ass in critical areas of the trough slightly increases flow velocity in the
vicinity of the walls. According to the calculations, the amount of entrai
ned slag can be reduced by reducing the height difference between the slag
and iron ports, raising the height of the bath level and reducing the heigh
t of the opening under the skimmer.