Radial gas distribution in the blast furnace top

Blast furnace process control heavily depends on good control of burden and gas distribution. For many blast furnaces this control relies on measurements with fixed above-burden probes, Therefore, an accurate knowledge of the gas flow between stockline and above-burden probes is of paramount importance. Measurements in the blast furnace top and calculations with a mathematical model are used to shed more light on the gas flow in the blast furnace top. It turned out that complex gas flows cause several differences between data at stockline level and at above-burden probe level. There is an acceleration of gas in the furnace centre due to the much higher temperature there. Gas from the colder intermediate region is therefore attracted towards the centre. There is hardly any influence of the inclination of the stockline. It is advisable to make the distance between stockline and above-burden probes as small as possible or to use some form of in-burden measurement.