| 摘要 |
<p>In a metallurgical furnace having a shaft heating section for use with sized material, an improvement wherein a plurality of projections is formed on the interior wall of the preheat zone of the furnace. The length of the projections is equal to 5 to 15% of the diameter of the shaft and the projections are spaced from each other a distance equal to two to ten times the length thereof. The projections may be formed as concentric rings around the interior wall of the preheat zone of the furnace or as a continuous helix formed on the interior wall. If desired, cooling tubes may be placed within the projections.</p> |
