| 摘要 |
<p>A rotary drum dryer (10) is disclosed which is useful in the production of asphalt paving composition. The drum (12) incorporates a burner (26) which defines a combustion zone, and a novel dam (30) and flight (34) construction is mounted to the interior of the drum (12) so that the flights (34) surround the combustion zone. The dam (30) is adapted to retain and raise the level of the aggregate flowing through the rotating drum (12) so that the flights (34) pass through the aggregate in the bottom of the drum, and the flights collect a portion of the aggregate on their top surfaces and carry the collected aggregate to an elevated discharge point (P), where the aggregate drops back to the bottom of the drum. The flights (34) serve to shield the metal wall (14) of the drum (12) from the radiant heat energy of the burner flame (F) which would otherwise result in its rapid deterioration, and they also serve to permit the aggregate to be effectively exposed to the radiant heat. The fact that more radiant heat energy is transferred to the aggregate, serves to further lower the temperature of the metal wall (14) of the drum (12). Still further, the fact that the flights (34) pass through the aggregate and are covered by the aggregate through a substantial portion of their circular path of travel, results in the flights (34) being exposed to less radiant heat energy and thus subject to less deterioration.</p> |
