| 摘要 |
PURPOSE: To prevent the atmospheric contamination by bitumen vapor and the clogging of a dust extracting gas filter by penetrating a burner and an aggregate carrying-in device into a drum on both ends of the drum so that the circulating directions of the gas and the aggregate are opposite to each other in the drum. CONSTITUTION: A drum 2 is provided with a burner 13 on one end 2b, a conveyor belt 6 for carrying in aggregate 7 on the other end 2a slightly higher than the one end, and a ring 32 for introducing a recycle mixture 27 between both the ends. The aggregate 7 put in the drum 2 is dried and heated by a high-temperature gas circulating in the opposite directions 30 between a drying zone 21 and a flame zone 22, and mixed with the recycle mixture 27 in a heating and mixing zone 23. According to this, the bituminous material included in the recycle mixture 27 is never exposed to the high-temperature circulating gas having the danger of accompanying bitumen vapor in the outlet direction of the drum 2.
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