Abstract:
Apparatus and method are disclosed for processing recyclable asphalt material. A drum has a polygonal cross-sectional configuration providing a plurality of substantially flat wall sides. Tubular breaker members within the drum are juxtaposed with corresponding flat wall sides. The relative location of the breaker members and the flat wall sides effects a cascading of recyclable asphalt material over the breaker members and between the breaker members and the flat wall sides as the drum is rotated so that recyclable asphalt material is tumbled within the drum, thereby simultaneously reducing the size of relatively large pieces to aggregate-sized pieces and heating the mass containing the desired aggregate-sized pieces for delivery of the heated mass from the drum.
Abstract:
A rotary drier for plants for the production of bituminous macadams with the use of recycled materials comprises a hollow rotary cylinder (2), heating means (9) connected to one end (4) of the cylinder (2), an aggregates infeed section (7) connected to one end (3), (4) of the cylinder (2), and a dried material outfeed section (8) connected to the other end (3), (4), an insertion section (24) for inserting recycled material into the cylinder (2), the insertion section being connected to an intermediate portion of the cylinder (2). The inside of the cylinder (2) is axially divided into a first, convection heat exchange zone (12), equipped with material tipping blades (14), and into a second, radiation and conduction heat exchange zone, and the cut material insertion section (24) is positioned inside the first heat exchange zone (12). A first group (25) of tipping blades (14) is mounted circumferentially inside the cylinder (2) between the insertion section (24) and the second heat exchange zone (13).
Abstract:
A method and template are provided for modifying an asphalt dryer/mixer that includes an outer drum and an inner drum with a plurality of mixing paddles, the two drums forming an annular mixing chamber in which asphalt cement and aggregate materials are mixed. The template comprises a bracket marking portion that is adapted to locate one or more brackets on the inner drum and a paddle reference portion that is adapted to locate the bracket marking portion with respect to a mixing paddle. A mixing paddle to be referenced for locating a bracket is selected and the template is placed on the inner drum with the paddle reference portion referencing the selected mixing paddle. The template is used to mark the location of the bracket, the bracket is affixed to the outer surface of the inner drum at the bracket location marked; and an agitation strand is attached to the bracket.
Abstract:
A counter flow VAM and RAP asphalt plant having concentric drums, each with a conveyor for introducing material, the concentric drums with a plurality of passages between them permitting material to move from the inner drum to the outer drum and from the outer drum into the inner drum, thereby permitting at least some material to proceed through the asphalt plant and bypass direct exposure to high temperature flame emitted by an internal burner.
Abstract:
A counter-flow aggregate dryer for an asphalt plant is equipped with a secondary feeder for introducing RAP or virgin materials intermediate the ends of the combustion zone of the dryer. Nonveiling flights in the combustion zone shield material carried through the combustion zone from direct radiant heat and veiling flights in the drying zone create a curtain of falling aggregates heated by a hot gas stream flowing in a countercurrent direction from a primary burner. A secondary burner elevates the temperature of the exhaust gas above its dew point temperature before delivery to the baghouse.
Abstract:
A drying and mixing plant is provided comprising a tapered inner drum (1) and an oppositely tapered outer drum (4) attached together concentrically and rotated as a unit. A burner (37) directs a hot air stream into the small end (2) of the inner drum (1). Material is fed into the small end of the inner drum, where impellers (40) lift it and drop it into the hot air stream and move the material through the inner drum (1) aided by the downward taper of the inner drum. The material exits the inner drum and enters the outer drum (4) where an additive material is introduced and mixed with the material (42) as both move through the chamber (28) between the inner and outer drums to a material outlet. The receiving end (5) of the outer drum (4) is enclosed in a shroud (12), therefore the air stream is directed through the chamber (28) between the drums, the chamber having an expanding cross section which slows the air down allowing fines to precipitate out. The device may include nozzles (17) for spraying water across the path of the air stream and material flow, and further may include, for fluid additive materials, additive nozzles (21, 23) spraying the additive material across the path of the air and material. A third drum (43) may be provided inside the inner drum (1), allowing separate addition of a third material (47), and further reducing fines in the air. The device is particularly suitable for mixing asphalt paving mix.
Abstract:
A drum mixer for heating, mixing and drying an aggregate material, such as a mixture of recycled asphaltic pavement and virgin aggregate. The drum mixer includes an inclined drum having a first end and a second end. The drum forms a pre-heating/blending section adjacent the first end, a heating/mixing section adjacent the second end, and a heating/drying/mixing section therebetween. A feed assembly for feeding aggregate material, preferably having a high ratio of RAP material to virgin aggregate, is provided. The feed assembly feeds the aggregate material into the pre-heating/blending section of the drum for movement of the aggregate material sequentially through the pre-heating/blending section, the heating/drying/mixing section and the heating/mixing section. A burner assembly extends from the second end of the drum into the heating/drying/mixing section of the drum. The burner assembly creates a high temperature gas stream which flows through the heating/drying/mixing and pre-heating/blending sections of the drum. Longitudinally extending tubular compartments are positioned in the heating/drying/mixing section of the drum so as to define a plurality of longitudinally-extending aggregate transporting channels. The aggregate transporting channels within the tubular compartments are out of direct contact with the high temperature gas stream while the tubular compartments are exposed to the high temperature gas stream. Thus, the aggregate material is heated, and dried indirectly by the high temperature gas stream as the aggregate material passes through the aggregate transporting channels.
Abstract:
A method of manufacturing and applying a novel pavement and patch material for roadways, driveways, walkways, patch for potholes and like surfaces, including the steps of reducing recycled asphalt roof waste to granules, adding aggregate and other solid recyclable materials to the granules, adding rejuvenating oil, adding emulsifier, adding asphalt concrete oil, adding anti-strip additives, adding liquid silicone, mixing the composition, heating the composition, applying the composition to the roadway or the like and compacting a new paving material.
Abstract:
A counter-flow asphalt plant with a separately controlled and operated dryer 50 and mixer 52 in which virgin aggregate, recycle material and liquid asphalt are mixed to produce an asphaltic composition. The dryer 50 is rotated by a variable dryer drive 58 about a central longitudinal dryer axis disposed at a dryer angle of declination. Within the dryer 50, aggregates are dried and heated by heat radiation and a hot gas stream generated at a burner head 112 of a combustion assembly 106 positioned inside the downstream end of the dryer 50. The downstream end of the dryer 50 is inserted within the first end of the mixer 52 for delivery of the heated aggregate. The mixer 52 is carried on a tiltable frame 54 and is rotated by a variable mixer drive 88 about a central longitudinal mixer axis disposed at a mixer angle of declination. The dryer 50 and mixer 52 are arranged so that the longitudinal dryer axis and the longitudinal mixer axis lie in a common vertical plane where the mixer angle of declination may be adjustably varied to be less than, greater than or equal to the dryer angle of declination. A recycle feeder assembly 120 feeds recycle material to the mixer 52 between the discharge end of the dryer 50 and the first end of the mixer 52. Liquid asphalt is sprayed from an injector 104 and mineral fines are added from a conveyor 102 extended into the mixer 52. Accordingly, the recycle and liquid asphalt are isolated from the burner head 112 and hot gas stream within the dryer 50, and the mixing cycles and residence times of the materials in the dryer 50 and mixer 52 can be independently controlled to improve economy and efficiency of plant operations by adjustably varying the respective speeds of rotation of the dryer 50 and mixer 52 and by adjustably varying the respective angles of declination of the dryer and mixer.