Device and method for preparing bituminous products

Claim 1

Device for preparing bituminous coated products from virgin aggregates and recycled bituminous mixes, said device comprising (a) a cylindrical drum (2) mounted for rotation about an axis (XX') of said drum and slightly inclined relative to a horizontal plane; (b) a burner penetrating through a first end of said drum, said burner having an elongated body (12) extending axially of said drum (2) as far as a flame zone (22), removed from said first end and a second end (2a, 2b) of said drum, in which a flame (16) is produced; (c) means (6) for conveying cold and moist aggregates into the drum (2) penetrating through said second end of said drum opposite first end; (d) a ring (32) for introducing recycled mixes into said drum surrounding said drum in a zone for introducing an intermediate recycled mix between said first and second ends of said drum; (e) means (10) for recovering precoated bituminous products at an outlet of said drum (2); (f) means (8) for collecting dust-laden gases circulating inside said drum, circulation of the gases inside said drum taking place in a direction opposite to circulation of the aggregates (7); (g) said drum comprising, sequentially from said first end (2a) to said second end (2b): (i) a drying zone (21) in which an internal wall of said drum (2) is provided with lifting vanes (25); (ii) said flame zone (22) in which said internal wall of the drum is provided with vanes (26) for keeping aggregates (7) against said internal wall of said drum (2); and (iii) a zone situated entirely downstream of said flame zone (22) and around said body of said burner, for introducing recycled mixes (23'), followed by a heating and mixing zone (23) in which said drum is provided on its internal surface with vanes (28) for mixing dried and heated aggregates and recycled bituminous mix, said device further comprising recovery means and a mixer (42) having a stationary housing (43) arranged at the outlet of said drum (2) so as to receive the bituminous products leaving said drum (2) by said recovery means (10), mixing means (44, 45) and a means (46) for introducing liquid bitumen into the stationary housing (43) of said mixer.