摘要:
An asphalt drum drying and mixing plant capable of using recycled pavement aggregate material includes two interacting drums, each being heated to different temperatures. A first drum is a parallel flow drying and mixing drum. The recycled material is introduced at the intake or feed end of this first drum and dried and heated to a comparatively low temperature in a first region of the first drum. A burner of relatively lower heat generation capacity furnishes heated gases. The recycled material is protected by supplying the gases through a cylindrical combustion chamber within which the fuel is completely burned such that no luminous gases enter the drum and contact the recycled material. A second, adjacent region of the parallel flow drum is the mixing region. The recycled material is transferred to the mixing region with close control over the temperature at which the material enters the mixing region. The parallel flow drum also has an intermediate feed chute through which virgin aggregate material is added. The virgin aggregate is heated in a counterflow drum to a temperature higher than the recycled material and the temperature of the final mix is controlled by changing the temperature of the virgin material. The exhaust from the mixing region is introduced as secondary air into the counterflow drum burner assembly. From the counterflow drum all gases are passed to a cleaning system including a cyclone separator and a baghouse filter. From the cyclone separator and the baghouse filter separated material and fines are routed into the mixing region together with liquid asphalt cement.
摘要:
A material transfer machine includes a slat conveyor of substantially the width of a feed hopper of a paving machine. The slat conveyor is supported by caster wheels to be disposed at an incline having a material intake end at a lower end thereof and a discharge end at the opposite upper end of the conveyor. The slat conveyor is mounted to a leading edge of the paving machine such that the upper discharge end is disposed above the feed hopper of the paving machine. A hopper is disposed ahead of the lower intake end of the slat conveyor, supported by a frame which is pivotably attached at a rear end thereof along the sides of the slat conveyor to an understructure thereof. The front end of the frame is supported by caster wheels, such that the frame is capable of joint movement with the conveyor and the paving machine while supporting pivotal movement in a vertical plane in response to grande changes of a base grade. Material is transferred from beds of supply trucks by backing the trucks toward the leading edge of the hopper to align the rear of the beds with the hopper. The material is dumped into the hopper and is transferred by the slat conveyor directly from the hopper of the material transfer machine to the feed hopper of the paving machine without getting into contact with the base grade of the road being paved.
摘要:
A push roll assembly mounted to a material receiving apparatus, such as a paver or other material receiving machine, includes a resilient link which allows energy transferred during contact of a supply truck with the push rolls to be gradually transferred to the material receiving machine, to thereby smoothen the impact between such truck and the machine.
摘要:
A paver of the floating screed type which is capable of operating with screed extensions for laying down pavement at various widths includes a self-contained, stowable and extensible grade reference system with a wide, planar adjustment range. The grade reference system provides an adjustment range for positioning a grade sensing device on either or both sides of the paver both forward and transversely outward from a selected support point on the paver. The grade reference system has a pivotally outer support member which permits the sensing device to become positioned at any selected setting of an arcuate path forward of a rearward position in substantial alignment with the leading edge of the screed to a forward position determined by the length of the member. The pivotal adjustment range of the outer support member is augmented by a transverse adjustment range effected by an extension or retraction of a corresponding support member to shift the pivot axis of the outer support member respectively outward or inward. The combination of the two adjustments provides for a mix of anticipatory grade change sensing combined with laterally outward extensions of the screed beyond the full extension range of the screed.
摘要:
A continuous process aggregate drying and mixing plant for producing a hot asphaltic material, such as is used for paving highways or the like, includes a combination of a drum drier and a pugmill. Both the drum drier and the pugmill are supported by a common trailer frame. The pugmill is coextensively mounted at the discharge end of the drum drier towards the rear of the frame. The drum drier discharges dried and heated virgin aggregate material through a feed and transfer chute directly into a first, pre-mix region of the pugmill. The feed and transfer chute also provides for the addition of recycled pavement to the heated and dried aggregate and for the side discharge of such heated and dried aggregate. A second region of the pugmill within which liquid asphalt is added to the mixed aggregate is substantially separated from the first, pre-mix region. The space above the second region of the pugmill is substantially enclosed and coupled directly to a secondary air supply of a burner for the drum drier. Thus, vapors emanating from the second region of the pugmill are drawn into the burner and burned to form environmentally friendly products.
摘要:
An ultrasonic grade and auger control for use on a road paving machine to compensate for uneven road surfaces is described. As the road paving machine travels, asphalt is centrally deposited along the road bed. An auger is connected to the back of the road paving machine and contains a series of spiral blades which moves the asphalt away from the center of the road bed toward its outer edges. The ultrasonic auger control apparatus detects the height of the asphalt positioned at the outer edges of the paving machine and regulates the speed of the auger to provide even distribution of the asphalt. A screed is located behind the auger to uniformly place and pack the paving material. The ultrasonic grade control apparatus regulates hydraulic actuators which control the thickness of the new road surface by adjusting the height of the screed.
摘要:
An adapter to permit an oil burner head to burn pulverized coal alone or in combination with other fuels features a manifold in the form of a mirrored pair of scrolls forming a part of the burner head. The interiors of the scrolls are divided into separate coal and air passages which open into the primary air passage of the burner head through outlets uniformly circularly disposed thereabout.
摘要:
A liquid fuel burner head features an axially movable primary air assembly carrying a centrally disposed nozzle spraying fuel radially of the burner head. Primary air ports surround the nozzle and include means for progressively increasing swirl of the primary air as radial distance from the nozzle increases and for adjusting the location of flame origin. Metering of secondary air and adjustment of its direction of swirl are both accomplished rearward of the secondary air outlet, the primary air assembly moving rearwardly to increase the secondary air as firing rate rises. A simple metal, frusto-conical flame holder is secured to and spaced forwardly of the burner head.
摘要:
An HMA plant which uses incidental heating of metal surfaces in combination with hot exhaust gases to pre-heat and pre-dry virgin aggregate material contained in an enclosed container which permits hot dry air to pass through interstices in the virgin aggregate material stored in the container.
摘要:
An HMA plant which uses incidental heating of metal surfaces in combination with hot exhaust gases to pre-heat and pre-dry virgin aggregate material contained in an enclosed container which permits hot dry air to pass through interstices in the virgin aggregate material stored in the container.