ISSN 2594-357X
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Abstract
In some non-blast furnace ironmaking processes, such as COREX smelting reduction process, the reducing gas, introduced into the upper pre-reduction shaft furnace, usually contains a considerable quantity of dust or powder as a result of coal gasification and iron-bearing burden decomposition in melter gasifier, and the powder distribution behaviors make direct and important influences on gas flow as well as burden reduction inside pre-reduction shaft furnace. Based on momentum exchange among gas-solid-powder phases and empirical equations, a two-dimensional mathematical model was established in the present work to simulate both dynamic and static holdups of powder. There were two blockade zones existing in the centre and edge regions near the bottom respectively. The dynamic holdup of powder firstly increased to 3.0e-3 and then decreased to 7.0e-4 as the gas ascended from the inlet to the top. At the bottom of the shaft furnace, the relatively low gas velocity gave rise to dynamic powder accumulation. By contrast, the static holdup of powder generally increased from 2.0e-5 near the edge to as high as 1.8e-4 near the centre at the gas inlet level and the trend was further promoted to 5.0e-3 in the central inactive zone or even to 1.0e-1 at the bottom below the gas inlet. In addition, the influences of the powder density, the feed rate and the man-made deadman shape on powder distribution behaviors inside pre-reduction shaft furnace were also investigated in this work.
In some non-blast furnace ironmaking processes, such as COREX smelting reduction process, the reducing gas, introduced into the upper pre-reduction shaft furnace, usually contains a considerable quantity of dust or powder as a result of coal gasification and iron-bearing burden decomposition in melter gasifier, and the powder distribution behaviors make direct and important influences on gas flow as well as burden reduction inside pre-reduction shaft furnace. Based on momentum exchange among gas-solid-powder phases and empirical equations, a two-dimensional mathematical model was established in the present work to simulate both dynamic and static holdups of powder. There were two blockade zones existing in the centre and edge regions near the bottom respectively. The dynamic holdup of powder firstly increased to 3.0e-3 and then decreased to 7.0e-4 as the gas ascended from the inlet to the top. At the bottom of the shaft furnace, the relatively low gas velocity gave rise to dynamic powder accumulation. By contrast, the static holdup of powder generally increased from 2.0e-5 near the edge to as high as 1.8e-4 near the centre at the gas inlet level and the trend was further promoted to 5.0e-3 in the central inactive zone or even to 1.0e-1 at the bottom below the gas inlet. In addition, the influences of the powder density, the feed rate and the man-made deadman shape on powder distribution behaviors inside pre-reduction shaft furnace were also investigated in this work.
Keywords
Mathematical model; Powder phase; Holdup distribution; Pre-reduction shaft furnace.
Mathematical model; Powder phase; Holdup distribution; Pre-reduction shaft furnace.
How to refer
Xu, Jian;
Wu, Sheng-li;
Guo, Xin-ying;
Du., Kai-ping.
NUMERICAL SIMULATION ON DYNAMIC AND STATIC
HOLDUPS OF POWDER INSIDE PRE-REDUCTION SHAFT
FURNACE
,
p. 414-424.
In: 42º Seminário de Redução de Minério de Ferro e Matérias-primas / 13º Seminário Brasileiro de Minério de Ferro / 6th International Congress on the Science and Technology of Ironmaking,
Rio de Jabeiro,
2012.
ISSN: 2594-357X
, DOI 10.5151/2594-357X-22110
