Abstract: A system and methods according to which a controller communicates control signals to a first frac leg, which includes a wellhead operably associated with a first wellbore, a valve operably coupled to the wellhead, opposite the first wellbore, a frac line operably coupled to the wellhead, and a zipper module operably coupled to the frac line, opposite the wellhead. The first frac leg includes a first sub-controller that receives control signals from the controller. A grease system lubricates the first frac leg and the zipper module. The grease system includes a second sub-controller that receives control signals from the controller. A second frac leg is operably associated with a second wellbore. The second frac leg includes a third sub-controller that receives control signals from the controller. The first, second, and/or third sub-controllers may receive control signals from the controller via a communication bus.

Abstract: Plant for the production and distribution of bituminous conglomerates and operating method of the plant, wherein the plant has a dryer having a first portion and of a second portion, which are connected to each other in series one after the other.

Abstract: A slurry and/or chemical blend supply apparatus suitable for providing slurry and/or chemical blend to chemical mechanical planarization (CMP) tools or other tools in a semiconductor fabrication facility, related processes, methods of use and methods of manufacture. The slurry and/or chemical blend supply apparatus includes one or more of the following: feed module, blend module, analytical module and distribution module.

Abstract: A method for utilizing recycled asphalt is provided. In exemplary embodiments, the method may comprise: mixing input feed with at least one of an asphalt rejuvenator and virgin liquid asphalt in a pre-coater/mixer; allowing the at least one of the asphalt rejuvenator and the virgin liquid to soften residual asphalt in the input feed and encapsulate any fine particles; discharging the mixture into a spiral section; feeding the mixture into a rotary dryer comprising a counterflow zone and a temperature elevation zone; activating the drying process and directing a heated air stream into the rotary dryer through a rotating chamber; allowing a portion of the heated air to escape through the counterflow zone and into the temperature elevation zone; liberating surface moisture from the mixture along with a portion of the heated air via an outlet; processing the exhaust from the system; and discharging a finished mixture.

Abstract: The present disclosure relates to industrial equipment for the hot recycling of asphalt mixes. The industrial equipment may comprise a portable bank of hoppers which may be used to meter RAP and unadulterated petrous materials and may be mounted on a supporting structure, along with gear motors which control the metering and send a signal to a flow indicator in a control panel where it may be recorded and controlled. A conveyor belt may be provided below the hopper bank in order to receive the material and transport same to a rotary cylinder comprising an industrial open-flame burner that may be used to transmit heat energy indirectly to the RAP and to the supply of unadulterated petrous material.

Abstract: A method for utilizing recycled asphalt is provided. In exemplary embodiments, the method may comprise: mixing input feed with at least one of an asphalt rejuvenator and virgin liquid asphalt in a pre-coater/mixer; allowing the at least one of the asphalt rejuvenator and the virgin liquid to soften residual asphalt in the input feed and encapsulate any fine particles; discharging the mixture into a spiral section; feeding the mixture into a rotary dryer comprising a counterflow zone and a temperature elevation zone; activating the drying process and directing a heated air stream into the rotary dryer through a rotating chamber; allowing a portion of the heated air to escape through the counterflow zone and into the temperature elevation zone; liberating surface moisture from the mixture along with a portion of the heated air via an outlet; processing the exhaust from the system; and discharging a finished mixture.

Abstract: The invention relates to a method and a plant for producing asphalt mixture and is directed in particular to the recycling of recovered asphalt. In order to achieve recycling of up to 100% recovered asphalt and to produce an asphalt mixture with the required quality, it is provided according to the invention that at least the drying and heating of the asphalt granulate and/or aggregates are carried out in a low oxygen atmosphere. The low oxygen atmosphere is achieved by supplying low oxygen gases with an oxygen content of maximum 10%, preferably with an oxygen content of maximum 5%. The conveyance of the heated and dried asphalt granulate and/or aggregates, the siloing and mixing with bitumen to form a new, incorporation-ready asphalt mixture also usefully take place in a low oxygen atmosphere.

Abstract: A thermic torpedo for preparing and delivering reinstatement materials has an internal chamber defining at least one compartment for containing graded aggregate and a second compartment for containing a stabilising agent, an external skin for insulating the contents of said internal chamber, a cap or lid for securely containing the contents of the torpedo in which is located at least one telescopic probe which can be driven through the compartments to heat and/or mix the contents thereof and at least one aperture through which the reinstatement materials may be expelled for delivery to a work site.

Abstract: A present invention provides for a system (100) for injecting cooling fluid into a concrete mixing container (502), the system (100) comprising a support structure (116) having a leg assembly with two or more supporting legs (201) and a cross member beam (200) supported between said two or more legs (201), the two or more legs (201) and the cross member beam (200) being positioned with respect to one another in such a manner as to define a passageway (210) of sufficient height (H) and width (W) between the two or more legs (201) and beneath the cross member beam (200) to allow passage of a concrete mixer truck (504) through the passageway (210) and a lance device (190) positioned on the cross member beam (200) of the support structure (116), the lance device (190) comprising an articulated arm that includes a rigid lance (102) which allows for the flow of a cooling fluid there through; and a means for acting on the articulated arm to cause pivotal movement of the articulated arm in a non-linear motion thereby

Abstract: An HMA plant which uses combination direct exhaust heated and indirectly steam heated pre-heating drum in combination with a sealed indirect hot oil heated rotary shaft mixer, where the steam given off from the heated HMA is maintained, separated from the sulfur containing exhaust of a hot oil heater, so as to minimize the production of acid in liquid form.

Abstract: A warm mix asphalt plant comprising a counter-flow drum, apparatus for precisely metering flows of A/C and water, an asphalt expander with no moving internal parts where a circular curtain of flowing clean water is mixed with a coaxial circular curtain of moving heated A/C to create asphalt foam which is heated and mixed inside a lower portion of the asphalt expander and then distributed to cover aggregate inside the counter-flow drum.

Abstract: 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.

Abstract: A warm mix asphalt plant comprising a counter-flow drum, apparatus for precisely metering flows of A/C and water, an asphalt expander with no moving internal parts where a circular curtain of flowing clean water is mixed with a coaxial circular curtain of moving heated A/C to create asphalt foam which is heated and mixed inside a lower portion of the asphalt expander and then distributed to cover aggregate inside the counter-flow drum.

Abstract: An HMA plant which uses combination direct exhaust heated and indirectly steam heated pre-heating drum in combination with a sealed indirect hot oil heated rotary shaft mixer, where the steam given off from the heated HMA is maintained, separated from the sulfur containing exhaust of a hot oil heater, so as to minimize the production of acid in liquid form.

Abstract: Methods and systems for efficiently manufacturing modified asphalt materials include agitating a base asphalt at a high shear rate using an in-line mixer while simultaneously exposing the asphalt to oxygen by blowing an oxygen-containing gas at a high gas flow rate through openings in the in-line mixer and heating the asphalt at an elevated temperature.

Abstract: A method of operating a paving system includes establishing a plan for paving a work area which is based on a positional temperature model. The method further includes receiving temperature data for paving material and comparing the temperature data with data predicted by the positional temperature model. Operation of the paving system is adjusted where actual data differs from model predicted data. A paving system and control system are provided having an electronic control unit configured to compare electronic temperature data with a positional temperature model for paving material. The electronic control unit can control machines of the paving system based on comparing actual data with model predicted data, and can further update either or both of a plan for paving a work area and the positional temperature model itself based on differences between actual data and model predicted data.

Abstract: When making moisture content adjustment by adding liquid such as water to a raw material such as pulverulent material including bentonite, uniform mixing of the liquid such as water with the raw material is given with relatively simple facilities, moisture content adjustment of a large quantity of raw materials is attainable, and besides, a material having satisfactory performances such as impermeability is obtainable through uniform moisture content adjustment. Within a mixing tank (1) configured with a normal powder mixer kept at low temperatures, pulverulent bentonite (A) and fine granular ice (B) are stirred and mixed. Stirring and mixing of the fellow pulverulent materials are adapted to uniformly mix the pulverulent bentonite (A) and the fine granular ice (B), enabling uniformly moisture content-adjusted bentonite to be obtained.

Abstract: The disclosure relates to a method for effectively and efficiently adding sodium trimetaphosphate to a gypsum slurry. In one exemplary embodiment, the sodium trimetaphosphate is added at the same time as foam is added to the gypsum slurry through the foam waterline. In another exemplary embodiment, the sodium trimetaphosphate is added at the same time as additional water is added to the gypsum slurry through the gauging waterline. The sodium trimetaphosphate can be added to either or both waterlines in its dry form or in a diluted solution.

Abstract: A method and apparatus for cooling a mixture with an injection system. The injection system is adjustable to accommodate the relative position and particular specifications of a given container (e.g., concrete mixer). In one embodiment, the injection system is operable to inject a coolant directly into the mixture while in the mixing process.

Abstract: A method of preparing a concrete composition includes utilizing a controller to control a process including circulating process water in a process water supply loop for a predetermined period while monitoring and controlling the temperature and flow rate of the process water, circulating aqueous-based air entrainment solution in an aqueous-based air entrainment solution supply loop for the predetermined period and controlling the flow rate of the aqueous-based air entrainment solution and after the predetermined period of time in which the flow of process water and aqueous-based air entrainment solution have stabilized, simultaneously actuating valves to divert and mix the process water, the aqueous-based air entrainment solution and compressed air to produce an air-entrained foam and mixing the foam with a concrete composition.

Abstract: 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.

Abstract: A warm mix asphalt plant comprising a counter-flow drum, apparatus for precisely metering flows of A/C and water, an asphalt expander with no moving internal parts where a circular curtain of flowing clean water is mixed with a coaxial circular curtain of moving heated A/C to create asphalt foam which is heated and mixed inside a lower portion of the asphalt expander and then distributed to cover aggregate inside the counter-flow drum.

Abstract: A present invention provides for a system (100) for injecting cooling fluid into a concrete mixing container (502), the system (100) comprising a support structure (116) having a leg assembly with two or more supporting legs (201) and a cross member beam (200) supported between said two or more legs (201), the two or more legs (201) and the cross member beam (200) being positioned with respect to one another in such a manner as to define a passageway (210) of sufficient height (H) and width (W) between the two or more legs (201) and beneath the cross member beam (200) to allow passage of a concrete mixer truck (504) through the passageway (210) and a lance device (190) positioned on the cross member beam (200) of the support structure (116), the lance device (190) comprising an articulated arm that includes a rigid lance (102) which allows for the flow of a cooling fluid there through; and a means for acting on the articulated arm to cause pivotal movement of the articulated arm in a non-linear motion thereby

Abstract: A method of manufacturing a bituminous coated aggregate mix, said method comprising at least the following steps: (a) course aggregate are dried by heating; (b) an intermediate mix is formed by coating the course aggregate with hot bitumen; and (c) wet sand is mixed with the intermediate mix obtained in step (b).

Abstract: An automated apparatus for preparing material samples includes a rotatable drum support assembly, a drum rotatably contacting the drum support assembly, a fan, and a powered drive mechanism. The drum includes a hollow main section and first and second hollow end sections attached to the main section. The first hollow end section includes a first end wall tapering to a first outer aperture. The second hollow end section includes a second end wall tapering to a second outer aperture. The fan is mounted approximate to the first outer aperture for establishing forced air flow through the drum toward the second outer aperture. The drive mechanism rotatably communicates with the drum support assembly for rotating the drum. The apparatus is useful for preparing samples such as paving materials for test such as the determination of specific gravity and absorption.

Abstract: A hot-mix asphalt manufacturing system includes a counter-flow rotary dryer having a combustion chamber, an inlet for dry ingredients, an outlet for hot-mix asphalt, and a pollution control device. The pollution control system includes a pre-filter, a cooling device and a fiber bed filter. Combustion gases from the combustion chamber are directed onto the ingredients for the hot-mix asphalt without substantial introduction of excess air or recirculated air and contact the hot-mix asphalt at a temperature substantially equal to the temperature of the combustion gases. The pollution control system removes substantially all particulates and hydrocarbons from the emissions from the hot-mix asphalt ingredients.

Abstract: A process and apparatus for creating an acoustically absorbent porous panel comprises the steps of dispensing cement and fibers with a dry mixer to create a dry mix and aqueous mixing water, surfactant and air with an aqueous mixer to create a foam. The process and apparatus provides for combining and mixing the foam and dry mix in a combining mixer to form a foamed cementitious material comprising on a wet basis about 53% to about 68% by weight cement, about 17% to about 48% by weight water, about 0.05% to about 5% by weight fibers, and about 0.01% to about 10% by weight surfactant. The foamed cementitious material is then dried or cured in a drying chamber. The dried foamed cementitious material may then textured with an embossing roller. The cementitious material provides good acoustical performance with enhanced durability and moisture resistance.

Abstract: An apparatus and method for testing asphalt in the field is described. The apparatus includes a motor for rotatively driving a chamber containing the asphalt to be tested. The chamber is rotated while cooler, ambient air is circulated through the asphalt particulate. After cooling the particles of the asphalt, the asphalt particles are separated by tumbling action.

Abstract: A method and apparatus for efficiently forming individual building units is provided, generally includes providing a plurality of molds, each capable of simultaneously forming a plurality of building units. Batches of cementitious slurry are individually mixed in order to control the density of each building unit formed. The ingredients are individually measured and combined into the mixing device. The cementitious slurry is then conveyed or transported and poured into one of the molds. The method provides the ability to control the amount of cementitious slurry in each batch in order to control to the extent possible the quantity of cementitious slurry poured into each mold and the ability to precisely control the dimensions of each building unit produced.

Abstract: A method for making aerated concrete blocks includes dispensing materials for making aerated concrete into a mold and allowing the materials to rise and stiffen into a body. The body may be divided into an array of blocks which are then cured. At least one passageway may be formed in each block, such as by drilling. The drilling may include drilling a plurality of spaced apart passageways through each block, and each passageway may have a circular cylindrical shape. The passageways permit easier grasping by the mason, reduce the weight without significantly compromising strength, and facilitate positioning of blocks during construction of a wall to facilitate the placement of vertical reinforcing members in aligned passageways. The positioning of the passageways in each of the blocks may assist alignment of adjacent passageways, especially at wall corners.

Abstract: A process for reclaiming salvaged asphalt includes feeding salvaged asphalt mixed with new sands, stones and tar in a designed proportion into a double-layer drying machine including inner and outer gyroscopic drums; indirectly heating the salvaged asphalt in the drying machine by using a plurality of burners disposed externally to dry the salvaged asphalt, the heat thus generated being recycled via a draft tube into the drying machine to further heat the salvaged asphalt until the tar in the mixture starts to soften at about 80° C.; and mixing the salvaged asphalt with tar to form rejuvenated asphalt product when they travel to the outer gyroscopic drum in which the temperature reaches and the temperature of the stones contained in the salvaged asphalt also reaches a temperature of 160° C. for fusion with the tar.

Abstract: A pulper in a stock preparation system includes a housing with a fiber inlet, at least one water inlet, at least one outlet and an inner chamber. A plurality of stationary pulping foils are attached to the housing and extend into the inner chamber. A rotatable shaft assembly extends through the inner chamber. The shaft assembly includes a shaft, an auger positioned around the shaft and relative to the fiber inlet and a plurality of movable pulping foils carried by and extending from the shaft. A conical valve is positioned in association with the outlet and is selectively movable to open and close the outlet.

Abstract: Molding sand of a used greensand mold is recycled by adding water and binder to sand particles fatigued by heating applied by a molten metal during molding and segregated from vigorous molding sand not directly heated by the molten metal and mixing the refreshed molding sand particles with the vigorous molding sand.

Abstract: A drum mixer is provided with a rotatable cylinder in which aggregates, reclaimed asphalt pavement and liquid asphalt are mixed to produce an asphaltic composition. The drum cylinder includes a first region, in which virgin aggregate is heated and dried by heat radiation and the stream of hot gases produced by a burner flame flowing in countercurrent flow to the aggregate itself to establish a highly beneficial heat transfer relationship. A second region doubles as combustion and mixing zones. In the mixing zone the reclaimed asphalt pavement and liquid asphalt is added and mixed with the aggregates. The combustion zone is formed along the center of the mixing zone by an elongated combustion assembly disposed along the central axis thereof. The combustion assembly and chamber extend from the discharge end of the drum through the mixing zone to the heating and drying zone to segregate the hot gases from the asphalt, thereby preventing degradation of the final product.

Abstract: Method and apparatus for producing mixtures containing bitumen, in which the material to be treated is conveyed by the force of gravity through a slit-type space between two vertically arranged heated surfaces.

Abstract: An asphalt production system utilizing a pair of rotatable drums for producing an asphaltic composition is provided. The asphaltic composition is produced by separately heating a volume of virgin aggregate material in a countercurrent drum dryer and heating a volume of recycle material in a parallel flow drum mixer. The hot virgin aggregate material is mixed with the heated recycle material at an intermediate location within the parallel flow drum mixer. A ducting system is provided for interconnecting the ends of the drums such that the hot exhaust gases from one drum are circulated into the other drum thus producing a common flow of exhaust gases between the drums.

Abstract: Method for manufacturing concrete by mixing concrete materials including a cement, aggregate, admixture and at least one of water and ice. The aggregate is moved prior the mixing and a low-temperature liquid is sprayed on the aggregate for cooling while the aggregate is being moved.

Abstract: A drum mixer is provided for producing an asphaltic composition. The drum mixer utilizes a first heat source located at an intermediate position within the drum mixer for producing a first current of hot gases directed towards the entry end of the drum mixer. The drum mixer also utilizes a second heat source located at the discharge end of the drum mixer for producing a second current of hot gases directed towards the entry end. Virgin aggregate is introduced into the drum mixer at the entry end of the drum mixer and is heated by the first current of hot gases. Recycle material is introduced into a mixing zone within the drum mixer between the first heat source and the discharge end. The heated virgin aggregate combines with the recycle material in the mixing zone and is further heated by the second heat source. Liquid asphalt is mixed with the virgin aggregate and recycle material in the mixing zone and the product is removed from the drum mixer at the discharge end.

Abstract: A method of heating reclaimed asphalt paving is shown and described. An air sorter removes fine materials from the reclaimed asphalt paving, and an air circulating dryer which utilizes high velocity air impingement, removes the moisture from the material. A conventional combustion heating tunnel is used to raise the temperature of the material to a first desired temperature and a microwave heating tunnel is used to raise the temperature to a final desired temperature.

Abstract: A reverse flow post-mixer attachment for direct-fixed asphaltic concrete mixers includes a modified discharge box for the downstream end of the drum and an enclosure for the downstream portion of the drum forming a passage along the exterior of the drum. If the smoke point of the liquid asphalt to be added to the material in the drum meets an established standard it is injected into the material upstream of the downstream end of the drum and discharged from the latter end in the normal manner. If the smoke point of the asphalt does not meet the standard, the material exiting the drum is diverted into the passage along the exterior of the drum and the asphalt added there out of the burner stream in the durm. The material and asphalt are then mixed and moved through the passage and finally discharged.

Abstract: A combustion housing for surrounding a burner flame is provided at an intermediate location within a drum mixer. An annulus is formed by the combustion housing and the interior of the drum adjacent thereto. Hot virgin aggregate is mixed with cold recycle material within the annulus. The mixing materials are further heated by conduction from the combustion housing surface and extending structures extending from the combustion housing into the annulus. The combustion housing is also provided with a plurality of openings for allowing radiant heat to enter the annulus and heat the mixing materials and for circulating combustible by products of asphalt production into the combustion housing for burning.

Abstract: A drum mixer having an countercurrent flow drying zone and a parallel flow mixing zone is provided for producing an asphaltic composition. The drum mixer utilizes a heat source located at an intermediate position therein for generating three streams of hot gases. The first stream of hot gases is directed towards the receiving end of the drum mixer in a countercurrent direction to the flow virgin aggregate entering the drying zone of the drum mixer. Recycle material is introduced into the drum mixer between the heat source and the discharge end thereof. The recycle material and the heated virgin aggregate are combined within the mixing zone. As both materials travel towards the discharge end of the drum mixer the second stream of hot gases is directed towards the discharge end of the drum mixer in a parallel direction to the flow of the mixing materials for heating said materials.

Abstract: Disclosed is a mobile sealant material apparatus comprising a frame adapted for vehicular movement and bearing a scraped-surface, indirectly-heated jacketed vessel for housing heated, fluid sealant material. Heated fluid heating media is heated in heating unit and pumped by a pump for recirculating through the jacket of the vessel in heat exchange relationship for heating sealant material housed therein and back to the media heating unit. A sealant material outlet line is attached to the vessel for withdrawing heated sealant material from the vessel. The sealant material in the outlet line also is being indirectly heated by the recirculated heating media from the media heating unit. Finally, sealant material pump is attached to the outlet line for selectively applying heated sealant material, e.g. applying crack sealant to cracks in roadways.

Abstract: A method of heating reclaimed asphalt paving is shown and described. An air sorter removes fine materials from the reclaimed asphalt paving, and an air circulating dryer which utilizes high velocity air impingement, removes the moisture from the material. A combustion heated recirculating air dryer or dryers is used to raise the temperature of the material to a first desired temperature and a microwave heating tunnel is used to raise the temperature to a final desired temperature. A recirculating air dryer which has sufficient velocity to form clear spots between wind rows on a conveyor belt is also shown and described.

Abstract: Process and device for fabricating bituminous coated products from aggregates enclosing a large quantity of fines, using a drying-mixing drum having a case (1) provided internally with fins of which some effect a complete raising of the aggregates in a drying zone (7, 8). Liquid bitumen is incorporated in the aggregates at the end of the drying zone (7, 8) with a raising of the aggregates. The hot mixing of the aggregates and the bitumen is effected in a zone (9) where the aggregates remain in contact with the wall of the drum. The excess fines in the hot gases at the outlet (3) of the drum are recovered. The process is also applicable in the use of recycled materials for producing the coated products.

Abstract: Asphalt plant apparatus comprising a drum dryer, a collection chamber or "knock-out box," a "baghouse," and a separate pugmill coater disposed directly underneath the collection chamber so that dust particles which settle out of the airstream in the collection chamber fall directly into the pugmill coater. The apparatus solves the problem of light-end hydrocarbon pollutants which can be stripped from liquid asphalt by contact with steam, in that the liquid asphalt is introduced not into the drum dryer but into the separate pugmill coater instead. Since no liquid asphalt is present in the drum dryer to coat and control the aggregate dust, the exhaust air from the dryer is more heavily dust-laden than that from a conventional drum mixer. However, the apparatus utilizes a collection chamber to compensate for the additional dust in the exhaust air by recovering part of that dust and dropping it directly into the pugmill coater, where it is mixed with the aggregate and liquid asphalt.

Abstract: An apparatus for recycling asphaltic concrete comprises an elongated rotatable drum in which composition is introduced at a first end and recovered at the opposite second end, and having a burner extending into the drum so that the burner nozzle is located within the drum intermediate the first and second ends and directs the hot gases toward the first end, and wherein the portion of the drum between the burner and the first end is provided with lifters of a type which prevent the formation of a veil of composition particles from falling through the hot gases of combustion as the drum is rotated, and a second portion between the burner nozzle and the second drum end and which is provided with lifters which cause a veil of composition particles to pass through hot gases of combustion as the drum rotates.

Abstract: The productive capacity of a drum heater and mixer for asphalt paving composition intended for processing recycled materials can be increased substantially by spraying a curtain of water vertically into the pathway of the raw material as it falls into the drum intake and before any substantial contacts with heated gases or flame and by spraying a curtain of water into the pathway of the heated gases and flame for controlling the temperature profile across the interior of the drum. The latter curtain of water is disposed at about thirty-five degrees to a plane perpendicular to the drum axis. Additional sprays of water downstream from the angular curtain of water may be supplied if necessary.

Abstract: Apparatus for recycling asphaltic concrete comprises an elongated drum having a first, open end, through which hot gases of combustion are directed and product is concurrently recovered, and a second, opposite end, through which composition to be treated is introduced, and means for closing the second end, except as necessary for introducing composition.

Abstract: An improved process for recycling asphaltic concrete comprises introducing asphaltic concrete particles at one end of an elongated rotating drum while supplying flame and hot gases of combustion to the drum at the opposite end, and introducing virgin aggregate into the drum intermediate the two ends. The asphaltic concrete is heated as it travels along a portion of the length of the drum and is recovered just prior to reaching the position along the drum length at which the aggregate is introduced. The aggregate is heated as it travels toward the end of the drum at which the flame and hot gases are introduced. Heated aggregate may be returned to the drum for further heating, and may be directed to the opposite drum end and mixed with the asphaltic concrete in a section of the drum.