Abstract: This application concerns methods and apparatus for use in industrial waste recovery operations such as recovery of non-consumed chemicals in industrial processes, with recovery of quick lime in a wood pulp process being an example. In some embodiments, methods comprise baking lime sludge in a kiln and controlling a temperature in a calcining zone of the kiln to be above about 2250° F. to vaporize sodium contained in the lime sludge. Interaction of the vaporized sodium with SOx can deter accumulation of one or both of CaCO3 and CaSO4 on one or more inner surfaces of the kiln. In some embodiments, lime sludge can be rinsed to generate a filtrate comprising dissolved NaOH, and the filtrate can charge a scrubber for removing SOx from an exhaust from the kiln. Embodiments of co-fired burners for heating such kilns by burning petroleum coke and natural gas are also disclosed.

Abstract: Techniques are generally described for producing cement clinker that includes forming cement clinker in a kiln, heating waste additives, and applying the heated waste additives to the cement clinker in the kiln. Additionally, examples are generally described that include an apparatus for producing cement clinker that includes a kiln in which cement clinker is formed and a device having an opening positioned inside the kiln which provides heated waste additives to the kiln for application to the cement clinker. An example device for applying waste additives to cement clinker includes an eductor configured to receive waste additives and transport air in which the waste additives are pneumatically entrained, and includes a lance coupled to the eductor and configured to receive the pneumatically entrained waste additives and receive a support gas that reacts with the waste additives and heats the same for application to the cement clinker.

Abstract: Disclosed is a process for reducing metallic oxide or sulfide materials in a rotary kiln and a rotary kiln for reducing such materials. The materials are heated in a reducing atmosphere as they travel along the axial length of the rotary kiln. The materials are discharged from the kiln at a discharge point in the kiln away from its lower material outlet end, wherein the temperature within the kiln at said discharge point is greater than the temperature at the lower material outlet end.

Abstract: A dryer (10) for an asphalt plant is disclosed. In one embodiment, the dryer (10) includes a generally cylindrical drum (12); a burner (20) having a burner head (22) at least partially disposed within the drum (12); a feeder (26) attached to a stationary portion of the dryer (10) for providing a recycled asphalt pavement; and an adjustable inlet (28) for introducing the recycled asphalt pavement from the feeder (26) into the drum (12) at a desired position. The adjustable inlet (28) is adjustable laterally between at least two positions.

Abstract: In a kiln whose interior is heated by combustion with oxidant having a higher oxygen content than air, streams of staging oxidant are fed into the space between the combustion zone and the inner surface of the kiln, and the stoichiometric ratios and amounts of oxygen in the combustion zone and in the overall operation of the kiln are adjusted to provide control or reduction of NOx formation while maintaining or increasing productivity of the kiln.

Abstract: A rotary drum configured for the efficient blending, cooling, and screening of granular products having an outer cylindrical shell, an intake end, and an exit or discharge end. The rotary drum is normally rotated at a predetermined speed by a conventional drive package. Disposed on an inner surface of the cylindrical shell is a plurality of compound helical flights and scoops or lifts, configured to blend granular product as it cascades from the intake end to the discharge or exit end of the rotary drum. A coaxially disposed cylindrical air passage adjacent the discharge end of the rotary drum, comprising an inner cylinder, that directs a counter flow of cooling air through the rotary drum towards the intake end, for cooling the cascading granular product as it approaches the screening segment of the rotary drum.

Abstract: A method for operating a counter-flow aggregate dryer for an asphalt plant in which primary aggregate materials are introduced into a first end of a horizontally rotating cylinder and travel to the second, discharge end of the cylinder through drying and combustion zones. Hot gases are generated in the combustion zone to flow in counter-current heat exchange relationship with the aggregate materials for discharge from the first end of the cylinder to air pollution control equipment. Secondary materials like RAP or virgin aggregates are fed directly into the combustion zone. The discharge gas stream is heated above its dew point prior to delivery to air pollution control equipment.

Abstract: A rotary drum heater for mixing asphalt with a hot gas introduced into the drum by gas burners is disclosed. The drum has an inlet opening for material to enter the drum to be processed and an outlet opening for material to exit. The hot gas is blown into the interior of the drum and is diverted by a hot gas conduit segment that is designed to gently heat the asphalt.

Abstract: A counter-flow aggregate dryer for an asphalt plant is equipped with a secondary feeder for introducing RAP or virgin materials intermediate the ends of the combustion zone of the dryer. Nonveiling flights in the combustion zone shield material carried through the combustion zone from direct radiant heat and veiling flights in the drying zone create a curtain of falling aggregates heated by a hot gas stream flowing in a countercurrent direction from a primary burner. A secondary burner elevates the temperature of the exhaust gas above its dew point temperature before delivery to the baghouse.

Abstract: A hot-mix asphalt manufacturing system including treatment of emissions and recirculated gases includes a counter-flow rotary dryer 12 having a combustion chamber 28, an inlet 24 for dry ingredients, an outlet 26 for hot-mix asphalt, and a plate collector 70 for treating recirculated gases. A fiber bed filter 90 (FIG. 5) is provided to remove hydrocarbons and particulates from the rotary dryer emissions before they are released into the surrounding environment. A cooling zone 92 is provided upstream from the fiber bed filter to cool the emissions to a temperature that is compatible with the fiber bed filter.

Abstract: A counter-flow aggregate dryer for an asphalt plant is equipped with a secondary feeder for introducing RAP or virgin materials intermediate the ends of the combustion zone of the dryer. Nonveiling flights in the combustion zone shield material carried through the combustion zone from direct radiant heat and veiling flights in the drying zone create a curtain of falling aggregates heated by a hot gas stream flowing in a countercurrent direction from a primary burner. A secondary burner elevates the temperature of the exhaust gas above its dew point temperature before delivery to the baghouse.

Abstract: Apparatus (1) and process for treating particulate material or powder (33) of a size capable of being fluidized in a retort (31) mounted for rotation on a pair of end axles (18, 41). Retort (31) is mounted on a tilt frame (5) for tilting movement in a vertical plane. Gas conduits (18A, 18B) are mounted within an axle (18) for the supply and exhaust of gas for retort (31). A conduit (55) mounted within the other axle (41) permits particulate material to be passed into or out of the retort (31) as shown in FIG. 1B. A removable injection assembly (90, FIG. 10) is utilized for the injection of additional particulate material. A removable sampling assembly (95, FIG. 11) is utilized for removing a sample of the particulate material from the retort (31). As the retort (31) is rotated, particles of the particulate material are constantly intermingled with each other and the walls of the retort (31). Microwave energy as shown in FIGS. 13-14 may be utilized to heat or dry materials within the retort (31).

Abstract: A drum mixer for heating, mixing and drying an aggregate material, such as a mixture of recycled asphaltic pavement and virgin aggregate. The drum mixer includes an inclined drum having a first end and a second end. The drum forms a pre-heating/blending section adjacent the first end, a heating/mixing section adjacent the second end, and a heating/drying/mixing section therebetween. A feed assembly for feeding aggregate material, preferably having a high ratio of RAP material to virgin aggregate, is provided. The feed assembly feeds the aggregate material into the pre-heating/blending section of the drum for movement of the aggregate material sequentially through the pre-heating/blending section, the heating/drying/mixing section and the heating/mixing section. A burner assembly extends from the second end of the drum into the heating/drying/mixing section of the drum.

Abstract: A drum mixer for heating, mixing and drying an aggregate material, such as a mixture of recycled asphaltic pavement and virgin aggregate. The drum mixer includes an inclined drum having a first end and a second end. The drum forms a pre-heating/blending section adjacent the first end, a heating/mixing section adjacent the second end, and a heating/drying/mixing section therebetween. A feed assembly for feeding aggregate material, preferably having a high ratio of RAP material to virgin aggregate, is provided. The feed assembly feeds the aggregate material into the pre-heating/blending section of the drum for movement of the aggregate material sequentially through the pre-heating/blending section, the heating/drying/mixing section and the heating/mixing section. A burner assembly extends from the second end of the drum into the heating/drying/mixing section of the drum.

Abstract: A waste incinerator which includes a housing formed by a heat insulating outer wall, air ducts; a decomposing chamber; a fire room; and a catalytic converter, all disposed in the housing. Waste is introduced into the fire room and incinerated there, and the remains are retrieved from the fire room in such a manner that the incoming materials such as air and waste on one hand the combustion gases and residue on the other hand form a counter flow heat exchange. Various embodiments are disclosed in which the fire wall is or not rotary.

Abstract: A inclined rotary drum mixer has flights for forming a veiling pattern of particles across the width of the drum for a substantial axial extent. The drum has a burner for flowing hot gases of combustion in heat transfer contact with the particle or aggregate veil. A diverter or interceptor is disposed in the drum for interrupting the cascading or veiling pattern to define a channel for flow of hot combustion gases free of heat transfer contact with the particles of the veiling pattern. By controlling the magnitude of the channel formed by the interceptor or diverter, the average exhaust gas temperature of the exhaust gases may be controlled.

Abstract: A flighted, horizontally inclined rotary retort, heated externally by flame, hot gases, steam or other sources of heat. The retort shall have sufficient flight area to transport the coal through the retort in the predetermined time. The coal being processed in this retort is prevented from becoming exothermic by provision for a countercurrent flow of blanket gas, heated to a predetermined temperature below exotherm, to prevent coal surface temperatures from rising above the ignition temperature. The retort accommodates oversize pieces of raw coal by having alternating long and short flights, thus allowing greater space between long flights and allowing the larger pieces to be carried over the center pipe by the wiping action of the long flights. The retort will also be provided with an internal pipe, mounted on the center line of the shell.

Abstract: In the processing of exhaust gases by a chlorine bypass system, a portion of kiln exhaust gases G is extracted from a kiln 1, after the extracted exhaust gases G are instantly cooled to 600.degree. C. to 700.degree. C. or less, the dust W in the cooled exhaust gases is separated to rough powder and fine powder by a separator, the separated rough powder is returned to the kiln 1 and the separated fine powder is discharged to a cement system, wherein extracting means extracts the kiln exhaust gases at the ratio more than 0% to equal to or less than 5% and the separating point of the separator is set to 5 .mu.m to 7 .mu.m.

Abstract: Contaminants are removed from particulate material in an inclined, rotating drum which has an inlet for contaminated material at its upper end, an outlet at its upper end for vaporized contaminants, an inlet for air that is located between the upper end and the lower end, and an outlet for clean particulate material at its lower end. Contaminated particulate material is admitted to the upper end of the drum and conveyed under the influence of gravity and the rotation of the drum to its lower end. A combustion chamber at the lower end of the drum is provided with an air inlet, a fuel burner and an outlet for combustion products. Fuel is burned in the combustion chamber with excess air supplied so that the temperature of the products of combustion is high enough to volatilize the contaminants in the particulate material, but not so high as to incinerate them. A fire tube within the drum conveys the combustion products from the combustion chamber to the upper end of the drum.

Abstract: An apparatus for the treatment of 100% reclaimed asphaltic pavement (RAP) uses low temperatures and no direct radiation from a burner flame to the RAP. The RAP is first heated in a counter flow drum which is supplied with hot combusting gases generated by a remote low NOx burner. The temperature of the drum input gases is preferably around 1100 degrees F and the output temperature of the gases may be 100 degrees F or less greater than the input temperature of the RAP. The RAP may be heated with a microwave oven to raise the RAP to a final temperature, although this step is not absolutely necessary in the counterflow design of this invention.

Abstract: A system for concurrently remediating contaminated soil and producing hot mix asphalt includes a single inclined rotary drum; a burner assembly with a burner head spaced intermediately within the drum and oriented to direct a flame and hot gas stream upstream therefrom; a secondary air tube for providing atmospheric air to the burner head for supporting combustion; a drying zone with veiling flights upstream from the burner head for receiving, drying and heating virgin aggregate; a combustion zone with combustion flights downstream from the drying zone and upstream from the burner head for receiving and remediating contaminated soil by heat transfer from the virgin aggregate, the flame and the hot gas stream and for oxidizing volatile contaminants vaporized from the contaminated soil; an isolated mixing zone for receiving various materials including the virgin aggregate, the remediated soil, recycle asphalt, and certain constituents for producing hot mix asphalt therein from thermal energy contained within th

Abstract: A method of destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500.degree. C. to heat the particulate material to a temperature in the range of from about 200.degree. C. to about 900.degree. C. in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end.

Abstract: An improved system for remediating soil contaminated with short-chain hydrocarbons, long-chain hydrocarbons and PCB's. The system includes an rotary drum having first and second heat exchanging regions, each containing separated inner and outer regions. The drum in inclined such that soil fed into the system with a sealed auger for remediation is gravitationally urged through the inner regions whereat thermal energy provided by a burner means, including clamshell ducts, remediates the soil by vaporizing and oxidizing the hydrocarbons and PCB's in a stream of hot gases.

Abstract: Oxygen is lanced into the main combustion reaction of a cement kiln to increase heat transfer to the clinker bed and to increase clinker production. Oxygen is separately lanced along the floor, i.e. the lowest wall of the kiln, to delay mixing with the flame to provide deep staging. The deeply staged oxygen flow is adjusted frequently to control emissions and stabilize the burning zone while the primary oxygen flow is maintained constant.

Abstract: An apparatus is disclosed for the separation and extraction of a waste material into a solid, a liquid, and a gas phase utilizing a rotating drum that is sealed from the atmosphere. The exterior of the drum is heated and the waste material flows through the interior of the drum where the liquid components are vaporized and the solids are dried. The drum includes a oxidizing section where the hot dried solids, after the majority of the liquids have been vaporized, are mixed with gas containing oxygen for oxidizing the remaining particles of oxidizable material in the solids. Hot exhaust gases flow through the interior of the drum in a counter current direction of the flow of the solids to maintain an inert atmosphere in the heating section where the vaporization takes place and to prevent the condensables from flowing back over the solids and condensing. The vapors flow through a chamber that contains a hot oil spray for removing solids from the vapors, and then flow to a condenser.

Abstract: A dryer for use in an asphalt plant for heating and drying virgin aggregate and also pre-heating reclaimed asphalt products (RAP). A drying drum cylinder having a burner at one end heats and dries virgin aggregate traveling therethrough. A second cylinder near the burner surrounds the drying drum and creates an annular cavity. RAP is introduced and travels through the annular cavity and exits adjacent the drying drum aggregate exit opening. Heat given off by the drying drum increases the temperature within the annular cavity and heats the RAP traveling therethrough. Heated aggregate and RAP first come in contact with one another after exiting the annular cavity and the drying drum and are, thereafter, delivered to a mixing drum.

Abstract: A rotary kiln (10) is employed which is inclined downwardly from its charge end (12) to its discharge end (14) and has a maximum length to breadth ratio of 5:1. The interior space of the kiln (10) is heated by means of at least one burner (B1, B2) directed into the kiln from one end thereof to a substantially constant elevated process temperature. Material is fed into the kiln (10) so that it occupies a maximum of 10% of the cross-sectional area of the internal space of the kiln (10) at the charge end (12). Upon entering the kiln the material is subjected almost immediately to the required process temperature. As it moves along the bottom of the kiln (10) from the charge to the discharge end (14), heat transfer to the material is primarily by radiation from the combustion space and from the lining of the kiln (10).

Abstract: A drum mixer asphalt plant is provided with a rotatable cylinder 10 in which virgin aggregate, recycle material and liquid asphalt are mixed to produce an asphaltic composition and the hot gas stream for heating and drying the materials flow in countercurrent relation. In a first zone within the cylinder 10, aggregates are heated and dried by heat radiation and a hot gas stream generated at a burner head 46 of a combustion assembly 40. In a second zone within the drum cylinder 10 isolated from the burner flame and hot gas stream by the combustion assembly 40, liquid asphalt is sprayed from an injection tube 76 to mix with aggregate materials. A recycle feed assembly 60 delivers recycle asphalt material to the second zone also for mixing with the aggregate and liquid asphalt.

Abstract: Material remediation apparatus includes a remediation drum through which materials, such as soil contaminated with hydrocarbons, are advanced from a feed end to a discharge end of the drum. A tube extending concentrically from the discharge end of the drum into the drum forms a combustion chamber. Materials being decontaminated advance through an annular space between the tube and the drum. The tube is axially first of converging and then of diverging shape, as viewed from the discharge end of the drum. A turbo burner injects combustible gases into the tube which are burned within the diverging shape of the tube. A portion of the burned gases reflow from the outlet of tube through the annular space to the discharge end of the drum. In a zone of the drum occupied by the tube materials are heated by conduction and radiation of energy passing through the wall of the tube as well as by convective heating from the reflow gases. Hot gases are exhausted from the drum at the feed end thereof.

Abstract: Material remediation apparatus includes a remediation drum through which materials, such as soil contaminated with hydrocarbons, are advanced from a feed end to a discharge end of the drum. A tube extending concentrically from the discharge end of the drum into the drum forms a combustion chamber. Materials being decontaminated advance through an annular space between the tube and the drum. The tube is axially first of converging and then of diverging shape, as viewed from the discharge end of the drum. A turbo burner injects combustible gases into the tube which are burned within the diverging shape of the tube. A portion of the burned gases reflow from the outlet of tube through the annular space to the discharge end of the drum. In a zone of the drum occupied by the tube materials are heated by conduction and radiation of energy passing through the wall of the tube as well as by convective heating from the reflow gases. Hot gases are exhausted from the drum at the feed end thereof.

Abstract: A method is provided for treating used potassium chloride (KCl) drilling mud for disposal. The process comprises feeding the mud into one end of a rotary tube, advancing the mud through the rotating tube and heating the mud by cascading action using lifters, to expose it to a hot gas stream, thereby partially drying the mud to lumps, further modifying the lumps by contacting them with a burner flame to form clinker pellets, and finally contacting the clinker pellets with a second flame to complete the drying process, producing dried clinker pellets containing the majority of the KCl in the mud, the pellets having a structure that resists the leaching action of water. The pellets further lend themselves to being evenly distributed over fields, so that unwanted excessive concentrations of KCl can be avoided.

Abstract: Burners for burning waste, comprising a conventional fuel nozzle and a waste slurry nozzle. Waste slurry nozzles, comprising a first conduit, a second conduit and an acceleration zone comprising a mixing chamber and an acceleration conduit. Waste slurries comprising a continuous phase and a solids phase, the solids phase consisting essentially of solids having at least one dimension less than about 1/8 inch and solids having no dimension less than 1/8 inch and no dimension larger than about 5/8 inch. Methods for burning waste, comprising feeding a slurry of cement raw materials to an up end of a rotating kiln, and ejecting a waste slurry from a burner such that a portion of the waste slurry lands in the calcining zone of the kiln.

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: In the initial part of a wet-process rotary kiln, means to decrease the amount of product dust entrained in the escaping combustion gases. Pipes running lengthwise of the kiln, in the region where the feed slurry is wet enough to flow, fill with slurry as they rotate through the slurry pool at the bottom of the kiln, and discharge their contents through exit ports so placed on each pipe as to emit streams of slurry when the pipe is carried by kiln rotation to a position near the top of the kiln. In conjunction with the forest of chains commonly used in such kilns, the transverse-flowing combustion gases are scrubbed of some of their entrained product dust content by its being entrapped in wet slurry and recycled.

Abstract: A thermal treatment system and method characterized by an outer drum mounted on the base for rotation about a rotational axis; an inner drum mounted coaxially within the outer drum closer to a heater end thereof than an inlet end of the outer drum, the inner and outer drums forming therebetween an annular flow passage surrounding the inner drum; a passage at a heater end of the inner drum for allowing material to drop from the inner drum into the outer drum for flow through the annular flow passage from its inlet end to its outer end; material conveying structure for conveying material within a feed tube from the inlet end of the outer drum to the inner drum for deposit within the interior of the inner drum at its inlet end, the feed tube being mounted coaxially within the outer drum and being spaced radially inwardly from the annular wall of the outer drum to form an annular flow passage surrounding the feed tube that has an inlet end connected to the outlet end of the annular passage surrounding the inner d

Abstract: A rotary kiln with primary air feed at the end wall of the rotary kiln is distinguished by the feature that at least two primary air nozzles are oriented relative to each other and to the fuel bed so that two oppositely directed vortices are generated within the rotary kiln, the axes of rotation of said vortices extending substantially parallel to the axis of the rotary kiln and said vortices rotating about said axes of rotation so as to promote the thermal convection-induced motion of the combustion gases.

Abstract: Burners for burning waste, comprising a conventional fuel nozzle and a waste slurry nozzle. Waste slurry nozzles, comprising a first conduit, a second conduit and an acceleration zone comprising a mixing chamber and an acceleration conduit. Waste slurries comprising a continuous phase and a solids phase, the solids phase consisting essentially of solids having at least one dimension less than about 1/8 inch and solids having no dimension less than 1/8 inch and no dimension larger than about 5/8 inch. Methods for burning waste, comprising feeding a slurry of cement raw materials to an up end of a rotating kiln, and ejecting a waste slurry from a burner such that a portion of the waste slurry lands in the calcining zone of the kiln.

Abstract: A rotary kiln has a rotatable cylinder through which a product passes in counter-current to a hot gas stream which dries the product. At the product entrance end, a vent annulus enters into the kiln for a length sufficient to allow entrained particles in the exhaust gas to either fall out within the rotating cylinder or pass through the annulus at a velocity sufficient to maintain their entrainment until discharge at a downstream location. Utilizing a vent annulus which enters into the kiln prevents entrained particles from becoming disentrained in the feed breech of the kiln which causes accumulation requiring periodic shut-downs for clean-outs which are disruptive of continuous operation. Utilizing the present invention incorporating a vent annulus in the rotary kiln minimizes down time and increases the efficiency and utilization of the rotary kiln. Additionally, the Separate vent annulus substantially simplifies the feed breech structure of the kiln simplifying construction.

Abstract: A transportable thermal stripping system for removing volatile organic compounds (VOC) from soil is provided. The system includes a vessel in which contaminated soil is placed into contact with a hot gas. The gas is discharged from the vessel and ambient air is introduced into the gas to ensure that the gas remains combustible. A blower circulates the gas to a cyclone separator where fine soil particles and ash are removed from the gas. Next the VOC in the gas are removed by combustion in a burner fired with a supplemental fuel. A portion of the combusted gas is exhausted to atmosphere and the remainder is recirculated to the vessel where the process is repeated.

Abstract: A process and apparatus for oxygen-enriched combustion of a fuel in an industrial furnace in which a preheated primary oxidant from a heat exchanger and a fuel to be combusted are introduced into a combustion chamber and ignited, a secondary oxidant having an oxygen concentration in excess of the concentration of oxygen in air is introduced into the combustion chamber downstream of the flame, and the resulting combustion products are exhausted. In accordance with one embodiment, the secondary oxidant comprises preheated oxidant aspirated from the heat exchanger using industrial-grade oxygen, resulting in an oxygen-enriched mixture being injected into the combustion chamber downstream of the flame. As a result, NO.sub.x emissions are reduced without adverse effects on the overall furnace operation.

Abstract: A high throughput apparatus and process for thermal remediation of soil contaminated with volatile organic compounds has a dryer with a high capacity heat source to volatilize and combust the compounds contained in a first lot of soil. The remediated soil is discharged and cooled. Hot gases and fines formed are drawn into a second dryer with an ignition source where a second lot of soil is used to cool the hot gases/fines mixture. A particulate control chamber is used to remove at least 75% of the fines from the gas/fines mixture. Gases containing uncombusted volatile organic compounds are directed back to the primary dryer for additional exposure to heat in order to complete combustion. Additional separation of the fines from gases is achieved in a baghouse.

Abstract: A method for producing a hydraulic binder using partially calcined raw meal entrained in the kiln off gases. The raw meal flow form the lowermost cyclone is interrupted at or near the junction of the meal chute, kiln inlet and riser duct. This flow interruption causes turbulence in the partially calcined meal facilitating dust entrainment in the gas. The splash plate can be selectively adjusted to entrain more or less raw meal. The entrained meal is drawn off from the riser duct through a kiln bypass duct, processed and hydrated to convert the calcium oxide in the meal to calcium hydroxide.

Abstract: A rotary kiln system wherein oxidant injection means are positioned at each stationary end and inject oxidant toward each other creating gas recirculation within the rotary kiln for improved mixing, combustion efficiency and temperature uniformity.

Abstract: An improvement to a drum drying and mixing apparatus includes a baffle plate arrangement is supported externally of the drum adjacent one end thereof and is inserted longitudinally from that one end into the drum. Baffle plates of the arrangement are disposed in the veil of materials in a drying section of the apparatus. Pivoting the baffle plates about an axis substantially transverse to the direction of the falling material in the veil modifies the veil to create a channel substantially void of material through at least portions of the veil. Hot drying gases moving longitudinally through the veil encounter a reduced resistance to the flow in the channel and divert from movement through the falling materials in the veil to move through the channel within the region of the veil. As a result the heat transfer from the drying gases to the aggregate materials is reduced and the final temperature of the hot drying gases exiting from the drum increases.

Abstract: An apparatus and method are provided for removing volatile organic compounds from soil in order to comply with environmental regulations. The apparatus is comprised of a rotating drum in which the contaminated soil is loaded. The drum contains an auger mechanism which aerates the soil. An air heater generates hot air which is directed to the drum and circulates there-through, causing rapid volatilization of the volatile organic compounds. The volatile organic compounds are then expelled to atmosphere. The removal of volatile organic compounds is conducted in a batch fashion, loading and unloading the drum following each processing cycle. The apparatus is mobile and may be transported to any clean up site.

Abstract: An apparatus for the removal of higher and lower volatility organic contaminants from media such as soil including an externally heated screw conveyor having an inlet, an outlet and one or more solid core flights, means for collecting and delivering media contaminated with higher and lower volatility organic contaminants to the screw conveyor inlet, at least one infrared radiation source external to the screw conveyor adapted to heat the media in the screw conveyor to a temperature above which at least one of the contaminants volatilize, and means for venting volatilized contaminants from the screw conveyor.

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: 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 continuous method of removing volatilizable organic composition from particulate mineral composition comprises heating the organic composition contaminated mineral particles in a rotating drum and exposing the particles to said hot gases to volatilize the organic composition from the mineral particles while advancing the particles counter-current to the direction of hot gas flow, removing a gaseous composition from the drum comprising a mixture of the gases of combustion, volatilized organic composition and airborne fine mineral particlles, separating the fine mineral particles from the hot gases and volatile volatilized organic composition, returning the separated fine mineral particles into the drum near the hot end, mixing the fine particles with the coarse mineral particles advancing toward the hot drum end, continuing to heat the mixture of fine and coarse mineral particles until the concentration of volatilizable organic composition is less than about 100 parts per million, and recovering a mixture of

Abstract: A mixer (10) consisting of a stationary casing (9), into which the outlet end (2b) of a rotary drum (2) opens, and mixing vanes fixed to the casing of the drum (2) and extending this casing axially in the direction of its outlet (2b). A burner (13) having an elongate body (12) projects into the drum (2) at its outlet end (2b) and opens into a flame zone (22). A recycling ring (32) is arranged around the drum (2) in the vicinity of the end (12a) of a burner. The casing (9) of the mixer delimits a mixing zone (36), separate from the flame zone (22), around the body (12) of the burner.