摘要:
Asphalt mix product is produced for delivery at a desired temperature and is comprised of a mixture of recycled asphalt product and virgin material in a specified, selected proportion of recycled asphalt product to virgin material. Recycled asphalt product is heated in an indirectly heated recycled asphalt product heater to an elevated temperature. Virgin material is heated, either in the same recycled asphalt product heater or in a separate virgin material heater, to a maximum temperature not exceeding a prescribed temperature above which damage to that heater will occur. The heated recycled asphalt product is mixed with the heated virgin material in the selected proportion of recycled asphalt product to virgin material to prepare the asphalt mix product for delivery at the desired temperature. By virtue of heating the recycled asphalt product and mixing the heated recycled asphalt product with the heated virgin material, the selected proportion of recycled asphalt product to virgin material is not limited by the maximum temperature of the heated virgin material, and asphalt mix product is produced effectively and economically with proportions of recycled asphalt product to virgin material which are considerably higher than heretofore available.
摘要:
An improvement is provided for controlling the temperature of recycled asphalt product being processed in an indirectly heated recycled asphalt product heater, and the temperature of component parts of the heater itself, as the recycled asphalt product progresses through the heater and is heated by heat transferred from gases at an elevated temperature passed through the heater. Temperature sensors are placed at strategic locations within the heater and provide temperature information to a central processor arranged to receive information pertaining to temperature from the temperature sensors and to process the information and generate control signals. A controller arrangement controls the temperature of the heated gases entering a heat exchange arrangement within the heater in response to the control signals such that the temperature of the recycled asphalt product and the temperature of component parts of the heater are maintained within a desired predetermined range of temperature.
摘要:
Asphalt mix product is produced for delivery at a desired temperature and is comprised of a mixture of recycled asphalt product and virgin material in a specified, selected proportion of recycled asphalt product to virgin material. Recycled asphalt product is heated in an indirectly heated recycled asphalt product heater to an elevated temperature. Virgin material is heated in a heater to a maximum temperature not exceeding a prescribed temperature above which damage to that heater will occur. The heated recycled asphalt product is mixed with the heated virgin material in the selected proportion of recycled asphalt product to virgin material to prepare the asphalt mix product for delivery at the desired temperature. By virtue of heating the recycled asphalt product and mixing the heated recycled asphalt product with the heated virgin material, the selected proportion of recycled asphalt product to virgin material is not limited by the maximum temperature of the heated virgin material, and asphalt mix product is produced effectively and economically with proportions of recycled asphalt product to virgin material which are considerably higher than heretofore available.
摘要:
Apparatus and method for processing asphalt material to be recycled by introducing used asphalt material from the field in relatively large pieces, as received from the field, into one end of a cage-like array of tubular breaker members while simultaneously heating the tubular breaker members from the other end of the cage-like array and rotating the cage-like array about a tilted central axis of rotation to tumble the material within the cage-like array and reduce the size of the pieces of material to a desired aggregate size within a mass of material moving toward the other end of the cage-like array, the tubular breaker members being spaced apart circumferentially such that only the desired aggregate-sized pieces in the mass of material pass radially out of the cage-like array for delivery and reuse.
摘要:
An improved screed for leveling abrasive paving material on a road surface. The improved screed is attachable to a typical road paving machine using standard mounting assembly and attachment components. The improved screed is highly abrasion-resistant and loses much less heat during shutdown periods than steel screeds because it is formed of a composite that includes a chromium-carbide alloy. The composite is formed of a relatively soft metal that is essentially completely fused to the chromium-carbide alloy. The highly abrasion-resistant alloy, which has a Brinell hardness in the range 550 to 600 and a low coefficient of friction, comes in direct contact with the abrasive paving material and its low thermal conductivity permits it to retain heat during shutdown. The relatively soft metal, which may be low-carbon steel, provides an easy and reliable surface for affixing standard attachment components, such as bolts to the improved screed, thereby providing an effective means for mounting to the paving machine. A curved leading edge of the screed prevents the paving material from welling up on the relatively soft metal upper surface of the improved screed. The curved leading edge is formed of the same composite as the rest of the screed.
摘要:
Recycled asphalt product is heated within an indirectly heated recycled asphalt product heater by passing heated gases through heat exchange members within a drum while the recycled asphalt product is moved through the drum from one end to the other end of the drum. The heat exchange members provide conduits for the heated gases, the conduits extending from an inlet adjacent a source of heated gases to an outlet communicating with an exhaust, each conduit following a looped path and having two or more segments each with a longitudinal length extending from adjacent one end of the drum to adjacent the other end of the drum. The segments are arranged serially in a serpentine configuration, are generally parallel to one another, and are spaced apart radially within the interior of the drum. Each inlet is coupled with the source of heated gases for longitudinal movement of the inlet relative to the drum along an inlet site adjacent the source of heated gases, and each outlet is connected to the drum for affixing the outlet against longitudinal movement relative to the drum at an outlet site adjacent one of the ends of the drum. The configuration and orientation of the conduits enable longitudinal expansion and contraction of the conduits in response to heating and cooling of the conduits, while the outlets remain essentially stationary at the outlet site.
摘要:
Apparatus for processing recyclable asphalt material includes an elongate drum having a generally cylindrical wall, a central axis, a first end and a second end, and being mounted for rotation about the central axis, with the central axis tilted at an acute angle so as to elevate one of the first and second ends relative to the other of the first and second ends, a heating chamber adjacent the first end of the drum, a plurality of breaker members arrayed generally parallel to the central axis of the drum and placed within the drum, a heat conduit extending along the drum coaxial with the breaker members, a heating arrangement for supplying heat to the heating chamber, ducting interconnecting the heating chamber, the breaker members, and the heat conduit serially such that heat from the heating chamber is conducted from adjacent the first end of the drum to adjacent the second end of the drum and is returned to adjacent the first end of the drum serially through the breaker members and the heat conduit, a feed arrangement for feeding the recyclable asphalt material into the drum, adjacent the elevated one of the first and second ends of the drum, and a rotational drive for rotating the drum, the breaker members and the heat conduit about the central axis so as to tumble the recyclable asphalt material within the drum, against the breaker members and against the heat conduit to process and deliver the desired recycled asphalt material adjacent the other of the first and second ends of the drum.
摘要:
Apparatus for processing asphalt material to be recycled by introducing used asphalt material from the field in relatively large pieces, as received from the field, into one end of a cage-like array of tubular breaker members while simultaneously heating the tubular breaker members from the other end of the cage-like array and rotating the cage-like array about a tilted central axis of rotation to tumble the material within the cage-like array and reduce the size of the pieces of material to a desired aggregate size within a mass of material moving toward the other end of the cage-like array, the tubular breaker members being spaced apart circumferentially such that only the desired aggregate-sized pieces in the mass of material pass radially out of the cage-like array for delivery and reuse, collecting and oxidizing pollutants emanating from the asphalt material being processed and, in an alternate embodiment, generating electrical power for use at the site of the apparatus.