Abstract: An apparatus and method for desegregating and conveying aggregate. A drag slat conveyor has a notch in the floor of its discharge end which causes larger aggregate at the lateral edges of the conveyor to drop out of the conveyor after smaller aggregate located between the lateral edges. The larger and smaller aggregate are thereby reoriented from a side-by-side lateral orientation to a longitudinal orientation. The longitudinally oriented segregated aggregate may then be thoroughly desegregated in a second conveyor.

Abstract: A dryer drum coater reduces blue smoke emissions by evacuating the blue smoke from the dryer drum coater independently of the exhaust of combustion products. The blue smoke, produced when heated and dried aggregate is mixed with other asphaltic products such as RAP or liquid asphalt, is preferably evacuated from a vapor outlet formed remote from the exhaust products outlet of the coater and adjacent the heated and dried aggregate inlet of the mixing chamber. Evacuating the blue smoke at this location obviates the need to separate the blue smoke from the combustion products and also prevents the introduction of excess oxygen into the combustion zone of the dryer drum coater. In a particularly preferred arrangement, the evacuated blue smoke is fed directly to the combustion air inlet of the coater's burner blower and is thereby incinerated.

Abstract: A bag cleaning apparatus removes caked dust from the bags of a baghouse and prevents the removed dust from being recaptured. The outlets of each bag subject to cleaning and all adjacent bags are closed during the cleaning process and for a sufficient time following the cleaning process to assure that the dislodged cake falls into the lower hopper of the baghouse. Provisions are also made to clean portions of each bag more than others, where necessary, and to vary cleaning among the bags to optimize baghouse efficiency. A reverse air flow cleaning technique is preferably employed because it provides gentler cleaning than other known bag cleaning techniques and thus increases the life of the bags.

Abstract: Apparatus for adjusting a conical concave crushing bowl of a gyrasphere crasher relative to a conical convex crashing head of the gyrasphere crasher includes a plurality of lugs connected to the conical concave crashing bowl; a bushing i) connected to the conical convex crashing head and ii) defining a bushing axis; and ii) defining a bushing axis a swivel bracket i) circumscribing an elongated trans cylinder release stud ii) defining a swivel axis that is coaxial with the bushing axis iii) adjacent the elongated bushing and iv) freely radially repositionable with regard to the swivel axis; and a tensioner having a proximal end attached to the swivel bracket and a distal end removably attached to one of the plurality of lugs. A method of adjusting the conical concave crashing bowl relative to the conical convex crashing head includes shortening the tensioner so as to rotate the conical concave crashing bowl relative to the conical convex crushing head.

Abstract: A gyrasphere crusher includes a crusher frame, a crushing head, and a crusher bowl which is selectively locked to and released from the crusher frame via operation of a bowl lock assembly including a clamping ring or locknut and an inflatable bladder device. The bladder device, which preferably is formed from a plurality of discrete bladder segments mounted on an axial end of the locknut, applies sufficient clamping forces to the locknut when it is fully inflated to prevent rotation of the locknut and bowl, and can be partially deflated to permit precisely controlled rotation of the bowl and thus adjustment of the crushing gap under load. The bladder operated bowl lock assembly is simple, reliable, and operates at a fraction of the pressures typically required for conventional mechanically applied/fluid-pressure released lock assemblies.

Abstract: A paving machine is described which includes: a gravity feed hopper located near a front end of a chassis; a distributing auger mounted on the chassis near the rear end thereof and extending transversely across the chassis; a remixing device including a variable-pitch screw auger with i) a first flight section and ii) a second flight section, the second flight section being located transversely between a lower discharge opening of the hopper and the first flight section, the pitch of the first flight section being lower than the pitch of the second flight section so that volumes bounded by flights of the second flight section are greater than volumes bounded by flights of the first flight section, so as to enable finer paving materials, located in a transverse central portion of the hopper to enter void spaces in volumes bounded by flights of the second flight section and combine with coarser paving material, thereby remixing segregated paving materials; and a discharge conveyor assembly extending longitudina

Abstract: A paving machine discharges HMA or other paving materials directly on top of a distributing auger located between the paving material storage hopper and the screed. The distributing auger is then capable of remixing any partially segregated paving materials and of uniformly distributing the paving materials directly adjacent a previously-paved segment. Materials may be discharged on top of the distributing auger from a discharge opening of a gravity feed hopper located adjacent the distributing auger or from an inclined conveyor delivering materials from a more standard hopper mounted near the front end of the paving machine.

Abstract: A dryer drum coater has an internal recirculation cylinder for promoting the recirculation of combustion products so as to entrain and incinerate blue smoke formed when heated and dried virgin aggregate is mixed with other asphaltic products such as RAP and/or liquid asphalt in the dryer drum coater. The recirculation cylinder acts to extend and strengthen natural eddy currents formed during operation of the coater such that combustion product recirculation which would normally extend only in the end area of the flame extends far enough toward the base of the flame to entrain the blue smoke and to draw the blue smoke into the base area of the flame. The cylinder may comprise a refractory lined stainless steel shell or may be formed from tee flights of the type used in the combustion zones of dryer drum coaters.

Abstract: A portable mineral processing machine has a chassis, a mineral processing device mounted on the chassis, and a control cab support mechanism operative to vertically raise the control cab from a lowered in pit transport position in which it is supported on the chassis to a raised operative position in which it is supported on the ground and elevated to a designated height above the chassis. The control cab support mechanism preferably comprises a scissor lift mechanism including upper and lower scissor mechanisms which are independently operated by respective upper and lower double-acting hydraulic cylinders or the like. The upper scissor mechanism is operative to raise an upper platform with respect to an intermediate support platform, and the lower scissor mechanism is operative to first lower a lower platform with respect to the intermediate support platform, and then to raise the intermediate support platform, upper scissor mechanism, and upper platform with respect to the lower platform.

Abstract: A rotary drum dryer has devices for cooling shielding flights located in the combustion zone of the drum. The devices comprise cooling flights which rotate with the drum to scoop up relatively small amounts of virgin aggregate from aggregate accumulated in the lower portion of the drum and to shower this aggregate over the outer radial surface of the shielding flights upon further rotation of the drum, thereby cooling the shielding flights without substantially decreasing the mean temperature of the aggregate. Cooling efficiency is enhanced by the continuous cascading of fresh aggregate over the shielding flights from the cooling flights through a substantial portion of the drum's rotation. The cooling flights and shielding flights preferably cooperate to limit or even prevent the showering of materials into the burner flame and thus inhibit burner flame quenching and accompanying emissions.

Abstract: An HMA plant has a catalytic reactor which can effectively and reliably reduce VOC and NO.sub.x emissions produced during plant operation. The reactor effectiveness is enhanced by exhausting the gas stream from a primary dryer of the plant at a sufficiently high temperature for effective catalytic reaction. Since withdrawal of gases from the dryer at these elevated temperatures necessarily reduces the effectiveness of the dryer, overall plant efficiency is maintained by using the treated gas stream from the catalytic reactor to heat further the aggregate in a secondary dryer, which is preferably a finishing dryer/mixer such as a fixed sleeve dryer drum coater. Poisoning of the catalyst is avoided by removing at least a large portion of the dust in the gas stream via a high efficiency cyclone prior to introducing the gas stream into the catalytic reactor. Ammonia or urea may if desired also be injected into the gas stream prior to its introduction into the catalytic reactor.

Abstract: A low-temperature thermal desorption (LTTD) system remediates highly contaminated soils. The system (1) reduces the concentration of vaporized contaminants exhausted from the primary treatment unit (PTU) and (2) precisely controls the concentration of vaporized contaminants exhausted from the PTU so as to permit the safe oxidization of contaminants in a secondary treatment unit without oversizing the secondary treatment unit or the baghouse. The concentration of vaporized contaminants exhausted from the PTU is reduced by drawing the vaporized contaminants into a low-pressure region of the PTU so as to contact the burner flame and by supplying this area of flame contact with a modulated supply of air to oxidize a designated portion of the vaporized contaminants within the PTU.

Abstract: A roadworking machine can be converted from front load road planing capability to cold in-place recycling capability by replacing the secondary conveyor on the front end of the machine with a mixer such as a standard pugmill. The machine can be converted in the field simply by detaching the conveyor from a-mounting assembly on the chassis and by attaching the pugmill to the same mounting assembly. The conveyor and pugmill are preferably attachable to the mounting assembly so as to be pivotable with respect to the chassis about both vertical and horizontal axes. The machine as thus constructed permits considerable versatility in both the discharge of milled materials from the secondary conveyor during front load planing and the discharge of recycled materials from the mixer during cold in-place recycling.

Abstract: Transport and erection of a portable asphalt plant are facilitated by transporting upper and lower subassemblies of the plant to a worksite on a single portable frame towed by a tractor. Once at the worksite, the frame is detached from the tractor and the upper plant subassembly is moved on the frame from a lowered transport position generally beside the lower plant subassembly to an intermediate position directly above the lower plant subassembly. The plant assembly is then completed by attaching the upper plant subassembly to the lower plant subassembly and raising the lower and upper plant subassemblies as a unit to a raised position which is sufficiently high to permit trucks to pass beneath the lower plant subassembly. An elevator is preferably transported to the worksite via another vehicle, then mounted on a pivot axis of the frame, and then pivoted about the pivot axis from a horizontal transport position to an upright operative position.

Abstract: A designated amount of recycled asphalt product (RAP) is fed to the pugmill of a batch asphalt plant during the production of hot mix asphalt (HMA) at a controlled rate so as not to overload the pugmill scavenging system. The designated amount of RAP is metered in a RAP weigh hopper, stored temporarily in a RAP holding hopper, and is then fed from the RAP holding hopper to the pugmill at a controlled rate. The feed of RAP to the pugmill, though electronically initiated, is preferably manually or automatically adjustable so as to avoid overloading the pugmill scavenging system while at the same time assuring adequate mixing of the RAP with the virgin aggregate and liquid asphalt. The scavenging system directs vapors removed from the pugmill to the dryer and preferably includes electronically operated dampers connecting the combustion air inlet of the dryer to the pugmill only during the mixing operation and otherwise connecting the combustion air inlet to the ambient atmosphere.

Abstract: A paving machine employs at least one gate mechanism which can selectively alter the weighting of the flow of paving materials from the discharge opening of a hopper by adjusting the contour of the effective lower edge of the gate mechanism. This contour is preferably adjusted by forming the gate mechanism from front and rear vertically adjustable gates, the lower edges of which have opposed tapers. The discharge of materials from the opening is weighted towards one side when the front gate is raised and the rear gate lowered or partially lowered, and is weighted towards the other side when the rear gate is raised and the front gate lowered or partially lowered. Discharge may be prevented altogether by fully lowering both gates.

Abstract: A drum mixer for heating and drying stone aggregate as part of a process of continuous production of asphalt paving composition, the drum mixer including: an elongate hollow rotatable drum having a length and an outer surface, the elongate hollow rotatable drum defining a central axis, a sleeve having an inner surface, the sleeve being mounted coaxially with the elongate hollow rotatable drum about the central axis and around at least a portion of the length of the elongate hollow rotatable drum and so as to define an annular chamber having an entire distance between the outer surface of the elongate hollow rotatable drum and the inner surface of the sleeve, and structure for mixing hot mix asphalt in the annular chamber including rake flights mounted on the outer surface of the elongate hollow rotatable drum and in the annular chamber including scouring structure for lifting hot mix asphalt up from a lower portion of the annular chamber along the inner surface of the sleeve through the annular chamber and on

Abstract: An asphalt drum mixer includes a rotating drum within a fixed sleeve which defines an annular chamber, and mixing tips mounted on the drum and in the annular chamber. The mixing tips pass through the hot mix asphalt laying in the bottom of the annular chamber and mix and shear the hot mix asphalt and increase its residence time in the drum mixer. In one preferred embodiment, the mixing tips may comprise curved scoop-like elements which lift the hot mix asphalt higher than conventional paddles and greatly increase residence time of the mix in the drum over conventional paddles. The quality of the mix is thus greatly improved. In another preferred embodiment the mixing tips may comprise curved scoop-like elements having slots which greatly increase sheering of the hot mix asphalt, thereby further improving the quality of the mix.

Abstract: A soil remediation system uses heat from remediated soil to vaporize volatiles from contaminated dust without pollution. Preferably, this remediation takes place in a dust remediator which is located proximate a primary treatment unit for contaminated soil, which vaporizes volatiles from the dust using heat from remediated soil, and which directs the volatiles into the primary treatment unit for oxidation. The primary treatment unit may comprise a rotary drum, and the dust remediator may comprise a shroud covering the remediated soil outlet end of the drum and receiving the remediated soil and the dust. The remediated soil and the dust are combined in the shroud so as to maximize vaporization of contaminants while minimizing agitation of the dust, and the combined soil and dust are then discharged together from a remediated products outlet of the shroud.

Abstract: A combustion chamber having improved heating efficiency and reduced NO.sub.x emissions includes a reduced diameter throat and a stepped configuration within the chamber. The chamber configuration encourages efficient combustion to reduce NO.sub.x production by promoting the formation of eddy currents within the chamber. A method for increasing heating efficiency and reducing NO.sub.x production is provided and involves passing combustion gases through such a combustion chamber.