Abstract: A burner (13) and a conveyor (6) for aggregates (7) into the drum (2) penetrate into the drum at opposite ends (2a, 2b). Circulation of the gases inside the drum occurs in direction opposite to circulation of the aggregates. The burner has an elongated body (12) arranged in the axial direction of the drum. The drum comprises, from the inlet end (2a) to the outlet end (2b), a drying zone (21), a flame zone (22), a zone for introducing recycled mixes (23') and a heating and mixing zone (23). The device may be associated with a mixer (42) of the conventional type in which the bituminous products (11) leaving the drum (2) are mixed with liquid bitumen and worked. The invention enables coated products for road surfaces to be prepared without the production of bitumen vapor.

Abstract: A kiln for reclaiming quick lime from calcium carbonate sludge formed in the production of cooking liquors in a wood pulping process for the production of paper. The kiln provides increased output with lower energy input due to: measurement and control of oxygen content in the kiln; non-air mixing burner; castable refractory liner with tumbler ribs; a heat transferring chain system; and a variable speed exhaust fan and air flow control. The output of the kiln was increased by more than ten percent along with a forty-five percent improvement in energy efficiency at substantial cost reduction due to its efficient use of energy.

Abstract: A combustion device for the pyrolytic destruction and gasification of industrial or other wastes, or lower sulfur fuels, is provided which includes an elongated cylindrical kiln body. Air is introduced into the kiln body by a plurality of pipes which define different combustion zones therewithin. A sorbent such as pulverized limestone may be introduced into each zone for reaction with the feedstock material to reduce undesirable flue emissions. The pipes are oriented within the kiln body to sweep the feedstock along the kiln body in a generally cyclonic pattern of torroidal shape and cross-sectional contour. The kiln may be rotated at various speeds corresponding to the force of the introduced combustion air to fluidize and entrain the feedstock material to be combusted.

Abstract: A system including a method and apparatus for treating waste containing organic contaminants which includes a direct fired, countercurrent, rotary kiln providing a soaking zone having an oxidizing atmosphere through which the materials being treated are passed after the unwanted organics are removed, and a secondary combustion chamber for oxidizing gases containing vaporized or pyrolyzed organics in which the organics are burned and are subjected to high temperatures for a holding time sufficient to effect destruction of the organic contaminants. The system includes means to minimize off-gas so as to make possible a reduction in size of the equipment employed.

Abstract: A gas-injection lance, burner, and method for use in a high temperature heating system which provides a nonaxisymmetric flow of a reaction-rate enhancing gas in sufficient proximity to the flame of the system, which extends over the surface to be heated, to create an aerodynamically rreduced pressure field sufficient to deform the flame and displace it in the direction of the surface to be heated. The present method provides substantially enhanced heating with the virtual elimination of hot spots.

Abstract: The present invention relates to a continuous drum dryer mixer apparatus and method for heating and drying virgin aggregates, as well as recycled asphaltic pavement materials and mixing such materials with liquid asphalt cement and other ingredients to formulate asphalt paving materials.A first cylindrical rotatable drum dryer has a first material input in one end thereof and a material output at the other end thereof. The output is directable at the option of the operator to either a hot elevator for carrying it to an asphalt batch plant or into a second concentric or offset rotating drum mixer. A burner is mounted either at the output end of the first cylindrical drum, or at the output end of the second drum and extends therethrough to the output end of the first cylindrical drum for directing a flame into the first cylindrical drum.

Abstract: Method and apparatus for treating waste materials to produce aggregates wherein pellets comprised of a mixture of solids, liquid wastes and clay are dried by hot air in a dryer. The pellets are then fed to the pyrolysis zone of a rotary kiln wherein they are heated by hot gas from an oxidation zone of the kiln to drive off most of the volatile gases. Remaining volatile gases and the fixed carbon in the waste are oxidized in the oxidation zone, and the silicates in the clay are vitrified in a vitrification zone of the kiln to produce aggregates which are crushed and screened. Volatile gases given off from the pyrolysis zone are mixed with exhaust gases from the dryer to feed the burner for the vitrification zone and to supply oxygen to the oxidation zone.

Abstract: For the production of a product which can be dumped or utilized, the mineral substances are subjected in a rotary kiln to a thermal treatment at a temperature at which the charge of the rotary kiln is transformed to a pasty to liquid slag phase. The composition of the charge is so selected that a slag phase is produced in which the main components, which constitute a matrix, are in the range from 60 to 72% SiO.sub.2, 10 to 30% Al.sub.2 O.sub.3 and 5 to 25% CaO+MgO, of said matrix, wherein the total percentage of SiO.sub.2 +Al.sub.2 O.sub.3 +CaO+MgO equals 100, the total of the main components SiO.sub.2, Al.sub.2 O.sub.3, CaO and MgO amounts to more than 60% on a dry and ignition loss-free basis, of the mineral matter which is charged to the rotary kiln. The slag phase discharged from the rotary kiln is cooled and the exhaust gas from the rotary kiln is purified.

Abstract: In a rotary tubular kiln for carrying out gas-solids reactions, comprising an indirectly heated, rotatable reaction tube with inner baffles which is provided with charging and removing devices for solid and gas inlet and outlet lines, the improvement which comprises forming the baffles as a central tube which is sealed on both sides and runs along the total length of the kiln, and a spiral which is tightly connected to the central tube and also to the outer rotatable tube. Lifting blades are uniformly distributed along the inner periphery of the rotatable tube. The kiln is suitable for carrying out oxidation, reduction, chlorination, roasting, decomposition, catalytic, annealling and/or cooling processes, e.g. the conversion of hematite to magnetite or goethite to iron.

Abstract: An apparatus and method for retarding the formation of a slag ring on the inner wall of a rotary lime kiln where coal combustion gases are used to provide heat in the calcining chamber of a rotary lime kiln. The inner wall of the kiln, at a predetermined location where a slag ring would tend to form, is cooled so as to cool the dispersed slag prior to contact with the inner wall of the calcining chamber sufficiently to prevent adherence of the slag to the inner wall. Cooling chambers or a cooling channel may be provided in the refractory lining forming the inner wall, or transpiration devices may be provided to inject coolant into the calcining chamber, at the predetermined location, to cool the slag and prevent adherence thereof to the inner wall.

Abstract: A system including a method and apparatus for treating waste containing organic contaminants which includes a direct fired, countercurrent, rotary kiln providing a soaking zone having an oxidizing atmosphere through which the materials being treated are passed after the unwanted organics are removed, and a secondary combustion chamber for oxidizing gases containing vaporized or pyrolyzed organics in which the organics are burned and are subjected to high temperatures for a holding time sufficient to effect destruction of the organic contaminants. The system includes means to minimize off-gas so as to make possible a reduction in size of the equipment employed.

Abstract: A method and apparatus for calcining limestone to produce lime wherein coal is combusted to provide heat for the calcination. The coal is combusted in a two stage combustion unit, with at least seventy-five percent of the slag formed by the coal combustion removed from the first stage of the combustion unit. Residual gases and fuel are further combusted in the second stage of the two stage combustor, with hot combustion gases therefrom, having the molten slag removed, fed directly to the calcining chamber of a rotary lime kiln. The coal may be carbonized to form a char and a fuel gas for use in the two stage combustor.

Abstract: A method for calcining carbonaceous materials in a rotary kiln is disclosed. An oxygen injection lance provides oxygen through the wall of a firing hood and into the carbonaceous bed, which is at an elevated temperature. The oxygen burns a portion of the carbonaceous material, providing the necessary heat for calcining the remainder of the carbonaceous materials in the kiln.

Abstract: A method and apparatus for same are provided to dehydrate a toxic chemical waste sludge to a powder by an internal heat source and to deposit said powder into a container, said apparatus receiving said sludge from a holding tank hopper having means for wiping said sludge into an auger, said auger serving to feed sludge to said apparatus, and said apparatus having an internal auger to move said dry powder to a storage container.

Abstract: A method as well as an apparatus for processing asphalt mixtures is provided in which broken-up used asphalt is employed and new material is added, utilizing a plurality of burner-heated drum devices, with the used asphalt component and the new material for the asphalt mixture to be processed or produced being processed, i.e. heated in particular, in respectively differently configured drum devices. The used asphalt component is heated separately in a drum mixer operated with parallel flow and the new material component is heated in a drying drum operated with counterflow. After leaving their respective drum devices, the components are conducted into at least one further connected mixer and are further treated there with fresh bitumen and possibly with filler material being added in the mixer. Furthermore, the exhaust gases of the drum mixer are introduced directly into the drying drum and are further heated there, thus combusting the CH.sub.x and CO component contained therein.

Abstract: Exhaust from a melting vessel passes through a transition section and into a rotary kiln to preheat batch material. A gas jet injects a high velocity gas stream into the transition section to alter its flow and reduce buildup of material due to entrained material in the exhaust leaving sticky deposits on interior surfaces of the transition section and kiln.

Abstract: An apparatus for and method of adjusting the effective length of a rotary kiln. Preheating gas enters the kiln, passes over a portion of the material to be heated and exits the kiln through an axially extending exhaust duct. Changing the length of the duct modifies the amount of time the material is subjected to direct heating by the gas so that the effective heating length of the kiln is changed.

Abstract: A rotary kiln, in particular, a kiln for reburning of lime mud, wherein the drying and intermediate zones of the kiln chamber are furnished in part with turbulence-forming baffle arrangements to produce a turbulent motion in the hot combustion gases and thereby to force the hotter gases, which flow through the axial central region of the kiln, out towards the kiln wall. The kiln shell is additionally furnished in part with thresholds in order to increase the transit time of the material through the kiln and further with lifters and a cog-wheel lining in order to lift the material and bring it into contact with the gases. The burner tube can be furnished with turbulence-forming baffles and the surrounding kiln shell with lifters and with thresholds at both ends of the burner tube. The baffles are preferably conical in cross-section with the apices coincident with the center of the cross-section of the kiln.

Abstract: A method and apparatus is disclosed for combustion of diverse materials, particularly combustible solids, liquids or gases, such as sewage sludge, refuse, coal, refinery sludge, tar sands, coal shale, coal tailings and spent foundry sand. A rotary combustion apparatus is employed which consists of a cylindrical drum, or other similar regularly shaped chamber, with a substantially horizontal axis of rotation including an ignition zone, a principal combustion zone, a falling temperature zone and a spent solids removal zone. The apparatus further includes solids transport chutes for forward and backward circulation of solids, arranged for the transfer of solids to or from one or more points. Feedstock may also be heated by recycled hot solids. The method and apparatus employs direct solids-to-gas contact established by lifting and cascading combustible solids through a hot gas stream.

Abstract: A drum-type drier and/or mixer in which particulate material such as aggregate or recycled asphalt is introduced into the forward end of the drum. A burner at the rear end of the drum directs its flame forwardly through an elongated firing tube which extends from the rear end of the drum toward the forward end thereof. The hot gases discharged from the tube strike a baffle, are deflected into an annular chamber between the tube and the drum and then flow rearwardly through the chamber to an exhaust stack. The particulate material also is advanced rearwardly through the chamber and, during such advance, is heated (1) indirectly by the hot gases flowing forwardly through the firing tube and (2) directly by the hot gases deflected into and flowing rearwardly through the chamber.

Abstract: A plant for manufacturing cement clinker from cement raw material includes a preheater first stage separated by a wall into a first chamber and a second chamber. Only raw material is passed through the first chamber while only hot exit gases are permitted to pass through the second chamber. Thus the raw material including any volatile, combustion components are kept isolated from direct contact with the hot exit gases. A heat exchange system is provided to permit the transfer of heat from the hot exit gases in the second chamber to the raw material in the first chamber. The heat exchange system preferably includes self-contained heat pipes extending into both the first and second chambers. The heat pipes contain a fluid medium which aids in the heat transfer as a consequence of cylical changes of the fluid medium from a liquid to a vapor state.

Abstract: A process for drying and/or calcining bulk material in a rotary kiln when hot gases are passed countercurrent to the flow of bulk material thereto, and the bulk material is dried and/or calcined in the rotary kiln is disclosed. According to the invention, the bulk material is dried and/or calcined, as it passes from the feed end of the rotary kiln to the discharge end thereof, by contacting the same with hot gases and thereafter, as the bulk material passes towards the discharge end of the rotary kiln, the bulk material is heated by indirect heat exchange with such hot gases. An apparatus for carrying out such process is also disclosed. The apparatus is a rotary kiln equipped with a centrally disposed tube, disposed axially within the rotary kiln toward the bulk material discharge end of the rotary kiln whereby an annular space is defined between the outer wall of the central tube and inner wall of the rotary kiln.

Abstract: A rotary furnace for recovering metals, such as aluminum. The furnace includes an outer cylindrical, open-ended drum which is mounted for rotation about its axis. Secured within the drum is a tapered kiln and the kiln is spaced inwardly of the drum to provide an annular chamber therebetween. Salt and aluminum dross and skimmings are introduced into the small diameter end of the kiln and heated, and the molten aluminum and salt are separately withdrawn from the large diameter end of the kiln. The construction of the furnace provides precise concentricity for the rotating kiln, thereby reducing bearing loads and the energy requirements for driving the kiln.

Abstract: A pulverized raw mixture is mixed in a vertical calciner with comminuted preheated fuel, which is burned in said vertical calciner to supply heat to said pulverized raw mixture in order to calcine the same. Hot exhaust gases from said calciner are used to preheat said pulverized raw mixture before it enters said calciner. The pulverized mixture which has been calcined is entrained out of said calciner in said exhaust gases and is separated from said exhaust gases and then fed to a rotary kiln and is burned therein to produce cement clinker. The cement clinker is cooled in a cooling air stream, which is thus heated. An exhaust gas stream consisting of at least part of the exhaust gases from the rotary kiln is fed into said calciner from below. The calciner is supplied with combustion air consisting of at least part of the thus heated cooling air. Said fuel is comminuted in contact with said exhaust gas stream and is then entrained into said calciner in said exhaust gas stream.

Abstract: Volatiles-rich dust and kiln gases are removed from a cement kiln by means of a special by-pass probe system located in the inlet end of the kiln. The probe system is designated to prevent the build-up of solidified volatiles-rich dust on the probe surfaces.

Abstract: Heating apparatus is disclosed that is particularly suited for use in combination with a drum mixer for treating asphalt aggregate materials to make such materials suitable for being applied to the ground surface. The heating apparatus generally comprises a plurality of flame-emitting gas burners and a combustion chamber for producing hot gases. A refractory lined plate assembly with an array of gas distributing ports is provided for spreading out hot gases discharged from the combustion chamber over the surface area of the plate assembly and also for inhibiting the open flames from passing from the combustion chamber. The combustion chamber is constructed to withstand the impacts and high temperatures encountered during operation of the mixer, as during transport, by attaching refractory bricks with metal backing plates to a rigid framework. The plate assembly is constructed in sections that are movable relative to one another to permit expansion and contraction with temperature variations.

Abstract: A method and apparatus for recovering flux salt and recycling or reusing the same in an aluminum refining method by introducing salt brine into a cylindrical evaporator with hot evaporator gas, rotating the evaporator to expose the brine to the hot gas and removing the slurry from the evaporator.