Abstract: An apparatus and method for heating and drying stone aggregate used in the production of asphalt, which also remediates and disposes of contaminated soil. Aggregate is introduced into a drum chamber of a fixed sleeve rotary drum mixer for heating. The aggregate is discharged into an annular chamber and mixed with contaminated soil that has been processed to be suitable for use in asphalt. As the soil is heated, the contaminants are vaporized and drawn into the drum chamber where they are oxidized by high temperature. Secondary aggregate in the form of recycled asphalt pavement (RAP) and/or virgin aggregate are also added to the annular chamber and mixed with the aggregate and soil to form asphalt and to cool the aggregate/soil mixture.

Abstract: A portable and self-erecting plant for the batch production of asphalt, and wherein the several components of the plant are split into two subassemblies which are initially mounted to the front and rear portions of a roadway transportable main frame. The front subassembly may be lifted to a first temporary position and then moved rearwardly to overlie the rear subassembly. The two subassemblies may then be interconnected to form an operational plant, which may be then lifted to its operating position as a unit. A separate elevator is provided which is also roadway transportable, and the elevator may be pivotally connected to the main frame so that it may be raised to an operative vertical position adjacent the plant.

Abstract: An asphalt finishing screed is disclosed which is adapted to achieve essentially complete compaction of the asphalt mix over a range of finished mat thicknesses. The screed comprises a vertically adjustable strike off bar, a rotary compactor positioned immediately behind the bar, and a screed plate positioned immediately behind the rotary compactor. In one preferred embodiment, the rotary compactor comprises a rotor which includes a plurality of freely rotating rollers about the peripheral surface thereof. In operation, the adjustable strike off bar is set at an elevation so as to meter the material to the rotary compactor and to achieve the desired compaction for the particular thickness of the finished mat being laid. The rotary compactor then impacts the mat in an essentially vertical direction and so as to achieve complete compaction of the mix.

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.

Abstract: A drum mixer is useful in the continuous production of asphalt paving composition, and has provision for the accurate control of the final temperature of the composition being produced. The drum mixer comprises a fixedly mounted cylindrical sleeve disposed in a generally horizontal orientation, and rotating blades for conveying the heated aggregate longitudinally through the interior of the sleeve. An opening is provided in the side wall portion of the sleeve, and a box-like enclosure covers the opening and mounts a plurality of sensor mounting tubes, so as to permit one or more sensors to be positioned at a location within the enclosure. The enclosure is located where the blades or mixing action in the sleeve will supply a regular flow of the aggregate into the enclosure, and so that the aggregate then slides over the sensors.

Abstract: A self propelled apparatus for digging a shallow trench along one side of a roadway is disclosed, and which is useful as part of a roadway widening operation. The apparatus comprises a cutter drum mounted to one side of the chassis of the apparatus, and a conveyor belt is mounted to the same side of the chassis with an inlet end positioned immediately adjacent the cutter drum and an elevated outlet end positioned beyond the forward end of the chassis. An enclosure surrounds the cutter drum so that the drum may be rotated in a downwardly cutting direction, and the loosened soil or other material may be lifted and guided around the drum and deposited onto the conveyor. The cutter drum includes one or more extensions which may be coaxially mounted thereto, so as to permit the width of the cutter drum and thus the width of the resulting trench to be selectively varied.

Abstract: An apparatus for heating and conveying a granular material is disclosed, and which comprises an elongate trough, and a framework mounting a plurality of transverse blades mounted above the trough. The framework is moved along a closed path of travel so that the blades move through a forward stroke, a lifting stroke, a return stroke, and a downward stroke which returns the blades to their original position. Thus a granular material may be moved along the length of the trough in a series of sequential steps. Also, the blades are internally heated, and the bottom wall of the trough is also heated, to effect heating of the advancing granular material.

Abstract: An apparatus and method for decontaminating petroleum contaminated soil and the like, and which comprises a rotary drum dryer which is adapted to convey the soil therethrough, and which includes a burner at one end for generating a heated gas stream which passes through the dryer to heat the soil to a temperature sufficient to volatilize the contaminates. A fixed enclosure is mounted to surround the discharge end of the dryer and the enclosure receives the heated soil as it is discharged from the dryer. Any entrained dust particles which are withdrawn with the exhaust gas stream from the dryer, and which may remain contaminated, are separated from the gas stream and returned to the enclosure. In the enclosure, the returned dust is mixed with the heated soil so as to cause the dust to be heated and to release its volatile contaminates, without risk of the returned dust being again entrained in the gas stream flowing through the dryer.

Abstract: A method and apparatus for producing a useful soil product from contaminated soil and sludge is disclosed, and wherein the contaminated soil is heated in a primary treatment unit to a temperature above the vaporization temperature but below the auto ignition temperature of the contaminates, so as to volatilize the contaminates. The volatilized contaminates are then delivered to a secondary treatment unit where they are heated to a temperature sufficient to be converted to non-toxic products, such as carbon dioxide and water. The hot purified soil produced in the primary treatment unit is conveyed to a mixing chamber, and sedimentary sludge is also conveyed to the mixing chamber, and during mixing, heat energy is transferred to the sludge so as to heat and substantially sterilize the sludge, and to thereby produce a useful soil product.

Abstract: An apparatus for feeding preheated aggregate material, such as for the production of asphalt. A feed hopper includes a heater within its interior and positioned adjacent a slotted discharge opening at the lower end of the hopper. A tent-like cover is positioned above the heater to deflect aggregate material from contacting the upper portion of the heater and to transfer heat to the aggregate material in a uniform and efficient manner. The heater may preferably be a gas-fired radiant heater extending lengthwise parallel to and for the full length of the slotted discharge opening. A series of hoppers may be arranged in side-by-side relation and a common conveyor positioned beneath the individual feed conveyors of each hopper to direct the preheated aggregate material to a subsequent processing apparatus, such as a drum mixer or other dryer, used for the production of asphalt.

Abstract: An apparatus is disclosed which is adapted to heat and dry stone aggregate useful in the production of asphalt paving, and which also has the ability to incinerate contaminated soil. The apparatus comprises a rotary drum for heating and drying the stone aggregate, and a separate rotary incinerator for incinerating the soil. The incinerator includes an outlet housing for withdrawing the incinerated soil and selectively conveying the soil so as to be mixed with the heated and dried aggregate, or delivered to a separate location. Further, the incinerator has an exhaust duct for conveying the gaseous products of combustion from the incinerator into the rotary drum, so that any volatile hydrocarbons contained in the gaseous products of combustion from the incinerator are effectively incinerated before being discharged to the atmosphere.

Abstract: A drum mixer which is useful in the continuous production of asphalt paving composition. The mixer includes a hollow drum which is mounted for rotation about an inclined axis, and the aggregate is introduced into the upper end of the drum so that as the drum rotates, the aggregate cascades through the interior of the drum and moves toward a discharge outlet at the lower end of the drum. A burner is mounted adjacent one end of the drum so that a heated gas passes through cascading aggregate. To permit the temperature of the exhaust gas to be maintained within acceptable limits so as to avoid detrimental effects to a downstream filtering baghouse, a gas flow bypass system is mounted in the downstream end portion of the drum.

Abstract: An asphaltic mix storage system has an improved conveying apparatus including a housing which is upwardly inclined from the horizontal so as to extend from approximately ground level to the top of a storage container. The conveying apparatus also includes a drag-type conveyor in the housing comprising an endless conveyor chain having spaced apart conveying blades carried thereby with the lower edges of the conveying blades in sliding engagement with the lower wall of the housing. The forward faces of the conveying blades and the lower wall of the housing define an acute angle therebetween to prevent carryover of asphaltic mix beyond the discharge chute at the upper end of the apparatus.

Abstract: An asphalt production plant which is adapted to process mixtures of recycled paving and aggregate, and which comprises a rotary drum dryer for heating and drying stone aggregate, and an elevator for conveying the heated and dried aggregate to an elevated discharge location. A batch tower is positioned adjacent the elevator, and the batch tower comprises an aggregate sizing screen which receives and segregates the aggregate by size, and several underlying aggregate storage bins, with each aggregate bin receiving aggregate of predetermined average size from the sizing screen. Also, a recycle bin is positioned between and in alignment with the aggregate bins. A weigh hopper is provided for receiving the aggregate and/or recycle material from the bins, and a pugmill is positioned below the weigh hopper for mixing the material with hot liquid asphalt and then delivering the resulting mix into an underlying truck.

Abstract: Cooling assemblies of the cooling apparatus each include an air atomizing spray nozzle located within a heated cooling chamber. An outer conduit interconnects the spray nozzle of each assembly and a source of cooling water. An inner conduit within the outer conduit interconnects the spray nozzle and a source of compressed air. Water passing through the outer conduit cools both it and the inner conduit. The outer conduit includes a flexible section that interconnects rigid sections and allows the latter to freely undergo differential expansive and contractive movement. Generally conical spray patterns produced by the spray nozzles form a circular array within the cooling chamber. Adjacent ones of the spray patterns abut each other and another nozzle spray pattern produced by a spray nozzle located generally centrally of the array and of the cooling chamber.

Abstract: An asphaltic mix batch apparatus which comprises a tower which mounts a number of aggregate storage bins, a weigh hopper underlying the storage bins, and a pugmill underlying the weigh hopper. Also, a screen assembly is positioned above the bins for segregating the aggregate by size, and such that the initial bin receives the more fine aggregate and the subsequent bins receive the more coarse aggregate. The initial bin has a relatively wide open top, and it receives a relatively broad gradation of the aggregate from its front to its back, with the front being disproportionately fine and the back being disproportionately coarse. A divider plate is positioned in the initial bin to prevent the gradation from interfering with the free discharge of the aggregate when the associated discharge port is opened, and to thereby provide a more uniform gradation being withdrawn through the discharge port.

Abstract: A rotary drum dryer is disclosed which is useful in the production of asphalt paving composition. The drum incorporates a burner which defines a combustion zone, and a novel dam and flight construction is mounted to the interior of the drum so that the flights surround the combustion zone. The dam is adapted to retain and raise the level of the aggregate flowing through the rotating drum so that the flights pass through the aggregate in the bottom of the drum, and the flights collect a portion of the aggregate on their top surfaces and carry the collected aggregate to an elevated discharge point, where the aggregate drops back to the bottom of the drum. The flights serve to shield the metal wall of the drum from the radiant heat energy of the burner flame which would otherwise result in its rapid deterioration, and they also serve to permit the aggregate to be effectively exposed to the radiant heat.

Abstract: A method for treating asphalt roofing shingles to be used for recycling in an asphalt plant which mixes asphalt roofing shingles with between about 15% and 50% by weight of a carrier aggregate. The aggregate is fed into a shredder with the shingles or is otherwise mixed with the comminuted shingles to form a recyclable asphaltic material which may be easily stored and transported, and which may also be used in the preparation of asphalt paving composition.

Abstract: An apparatus is disclosed which is capable of efficiently decontaminating soil, and which has several common components with a conventional asphalt production plant. This feature permits a conventional asphalt plant to be retrofitted by the addition of a relatively small number of additional components, so as to permit the apparatus to selectively produce asphalt, or to decontaminate soil. When operated in the configuration for decontainating soil, the soil is initially heated to a temperature above the vaporization temperature but below the autoignition temperature of the contaminants, so as to volatilize the contaminants. The volatilized contaminants are then delivered to an incinerator, wherein the volatilized contaminants are heated to a temperature sufficient to be converted to non-toxic products, such as carbon dioxide and water.

Abstract: An apparatus is disclosed for heating and drying stone aggregate useful in the production of asphalt, and which also has the ability to incinerate contaminated soil. The apparatus includes a rotary drum dryer for heating and drying the aggregate, and a rotary incinerator for incinerating the soil. The discharge ends of the rotary dryer and incinerator are positioned so as to oppose each other, and a breeching is provided for enclosing and interconnecting the two ends. The breeching includes a diverter gate, so that the incinerated soil may be either added to the heated and dried aggregate, or directed to a separate external stockpile. The incinerator has a refractory lined interior having a plurality of air inlet tuyeres which are spaced along its axial length so as to provide for the staged combustion of the volatilized contaminants in the soil, to thereby result in low NOx emissions.