Abstract: An asphalt plant for producing asphalt paving, the asphalt plant including: a) a dryer unit for heating stone aggregate, the dryer unit including a container and a burner for producing a flame to provide thermal energy for heating the stone aggregate in the container; b) a supply of burner fuel for providing fuel for the burner flame; c) a supply of burner air for providing oxygen to the burner flame; and d) the dryer unit including a grate which is spaced from the burner, the grate defining a plurality of openings, such that the burner flame extends through the openings, and such that the grate improves the thermal efficiency of the dryer unit for heating the stone aggregate.

Abstract: A treatment system and method is disclosed for heat treating aggregate, for example, an aggregate dryer of the type which uses a burner and rotating drum for veiling aggregate into a thermal flow path. The invention provides a plurality of mixers which safely mix fuel and oxidant into a premix which is delivered to a reaction chamber The premix is combusted and recirculated within the reaction chamber to insure uniform and complete combustion, resulting in lower emissions of pollutants such as carbon monoxide, volatile organic compounds, and nitrogen oxides and also lower combustion roar. This uniform and complete combustion results in a more uniform thermal profile within the rotating drum, resulting a greater throughput of processed aggregate and a more efficient consumption of energy.

Abstract: A rotary incinerator for disposal of industrial waste is provided. The incinerator is slopedly and rotatably disposed to a slant support and has a plurality of spirally arranged tubular conveying ribs on entire inner periphery for squeezedly transmitting the incinerating waste from the lower portion to an exit in the tapered upper end so that the waste is stirred while incinerating and the slag and ash are automatically discharged via the exit, a combustion system worked together with a ventilation system at a lower end for supplying the flame and the fresh air into the incinerator, a drive system for driving the incinerator to rotate and a control device for controlling the operation of the above recited elements. The improvement is characterized in safe and rapid incineration of the industrial waste, therefore, economical.

Abstract: An equipment for and a method of calcining mineral materials comprising a precalciner consisting of a combustion zone followed by a reaction zone and then by a contact zone and by a post-combustion zone, the latter communicating itself with a separating cyclone, the reaction zone being fed with smokes coming from a firing furnace, the supply of mineral material being distributed between the combustion zone and the contact zone, the invention being applicable in particular to the manufacture of cement clinker while considerably decreasing the emission of nitrogen oxides.

Abstract: A partial flue gas stream is extracted from the rotary kiln of a cement plant. This partial bypass of hot flue gas is passed through a cooler (23) and then passed through a dust collector (24). Fine granular dust (30) from the dust collector (24) is fed directly to a dust collecting vessel. The coarse granular dust (28, 29) from the dust collector (24) is fed to a suspension type cyclone heat exchanger (33) operated directly with cooling air (32) and there cooled by means of direct heat transfer. The heated cooling air (39) extracted from the hot dust cooler (33) by a draft fan (40) is fed to the partial flue gas stream, such as by feeding it to the gas stream cooler (23).

Abstract: The invention relates to a method and a plant for manufacturing mineralized portland cement clinker. The method and plant provides for preheating, calcining, burning and finally cooling the clinker. The mineralizer may e.g. be gypsum, fluorine, or a waste product containing these or other mineralizers. The mineralizer is added to the feedstock after the feedstock has been fed to the process, preferably after the cyclone which handles the feed to the calciner, i.e. the last cyclone in the preheater, or the lowermost preheater stage in a plant which does not incorporate a calciner.

Abstract: A sintering method of cement clinkers in which preheated cement raw material powder is granulated and sintered in a fluidized bed granulating and sintering furnace, and granulated and sintered clinkers are introduced into a cooling device, for manufacturing high-quality cement clinkers by use of a single fluidized bed-granulating and sintering furnace efficiently with a small heat loss, wherein clinkers are discharged from the fluidized bed granulating and sintering furnace through a clinker dropping hole which is provided in a fluidizing gas distributor of the furnace or in a radial direction extending from the gas distributor, an opening area of the clinker dropping hole is regulated by a gate portion to maintain the differential pressure in a fluidized bed within a predetermined range, air for classifying and cooling the clinkers is blown into a discharge chute connected to the clinker dropping hole, the amount of the blown air is regulated to make the flow velocity of the air blowing from the clinker drop

Abstract: A furnace body (4) consists of drums (D1, D2, and D3) which are supported and drove by rotation drive assemblies (3) independently of each other. Each drum has open ends at both sides, and adjacent open ends are engaged to each other in a rotatable manner. One open end of the furnace body (4) are provided with a waste feeding assembly (6), and the other is provided with a gas exhausting assembly (7). Oxygen supply units (5) are connected to the joint between the open ends of adjacent drums.

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: A bypass system is provided for a long cement kiln. The long cement kiln includes a cylindrical rotary vessel in which a kiln gas stream flows countercurrent to in-process mineral. The bypass system includes an annular bypass plenum, a port in the wall of the rotary vessel in gas flow communication with said plenum, and a draft tube for preventing passage of in-process mineral through said port. A blower fan induces flow of at least a portion of the kiln gas stream to form a bypass stream through the draft tube and the port and into the annular bypass plenum. The bypass system also includes an apparatus for mixing controlled amounts of ambient air with the bypass stream to cool the kiln gas bypass stream and to precipitate alkali fume in the kiln gas bypass stream before it passes through the draft tube and the port in the wall of the rotary vessel to reduce build up of condensed alkali inside the draft tube.

Abstract: A method and plant for burning sludge or filter cakes during the cement clinker manufacture where the cement is manufactured in known manner by the cement raw meal being preheated, calcined and burned into clinker with subsequent cooling of the clinker and where the sludge is dried and finely divided prior to burning. The drying heat is provided by feeding hot raw meal from either the preheater or a separating cyclone installed in connection with the calciner to the drier unit, which may be a drier crusher. Applicable types of sludge include sewage sludge, beaching earth, paper sludge, fibre rejects, combustible chemical residues, e.g. waste derived from the manufacture of nylons and pesticides, and drill sludge resulting from oil exploration.

Abstract: A combined soil remediation and HMA plant is provided having a rotary dryer, a rotary soil incinerator, and a refractory lined duct connecting the incinerator to the dryer and serving as a conduit via which hot gases, forming the primary and possibly sole heat source used to heat raw aggregate in the dryer, are conveyed from the incinerator to the dryer. The duct also acts as an afterburner in which volatile organic compounds, particles of contaminated dust, and other combustible products not destroyed in the incinerator are destroyed. The plant further includes a mixer 1) receiving both reclaimed soil from the incinerator and heated and dried aggregate from the dryer and 2) mixing both materials with liquid asphalt and possibly RAP and/or dust from the system's baghouse assembly to form HMA.

Abstract: A premix burner assembly for heating the combustion chamber of a dryer for an HMA plant, soil remediation plant, or the like is designed to meet the very low emission limitations that are imposed in certain areas such as the southern portion of California. The burner assembly includes a burner, a primary nozzle, an air source connected to the burner, a fuel source, and a fuel injection system connected to the fuel source and to the burner. Premixing is achieved through the supply of a gaseous fuel from the fuel injection system into the burner upstream of the primary nozzle so as to lead to nearly complete premixing of the air and fuel prior to discharge into the combustion chamber, thereby permitting combustion of the fuel with only very small amounts of excess air. Burner efficiency is increased and emissions are further reduced by employing air distribution and control devices upstream of the fuel injection system and by carefully controlling the supply of both air and fuel to the burner.

Abstract: A description is given of an apparatus for shooting of whole automobile tires, preferably into a cement rotary kiln, which apparatus comprises a gun barrel, a charging device for placing automobile tires in the gun barrel, and a device for generating compressed air for propelling the automobile tire through the gun barrel. The gun barrel consists of a tube having a cross-section which is essentially rectangular over its entire length. By designing the gun barrel with a cross-section which corresponds to the cross-section of the automobile tire, the automobile tire will fill out the entire cross-sectional area of the gun barrel thereby making it possible to provide an air pressure behind the automobile tire which is sufficient for propelling the tire through the gun barrel.

Abstract: A cooler (6) for cooling of particulate material which is subjected to heat treatment in the rotary kiln is mounted at the material outlet end (1) of a rotary kiln. The cooler is provided with annular chambers (7, 8, 9) disposed around each other, and which are successively passed by the material from the outlet (5) of the kiln to a material outlet (20) in the stationary housing (15) of the cooler in countercurrent with the cooling air which flows from an air inlet (18) and through the annular chambers to the kiln in which the air thus heated is utilized as combustion air.

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

Abstract: An apparatus for sintering cement clinker with a spouted fluidized bed granulating furnace and a fluidized bed sintering furnace is provided which includes a perforated distributor having a multiplicity of nozzle holes through which gas for granulating injected raw material for cement while spouting and fluidizing the same is introduced; a dropping port through which granulated raw material for cement is discharged and which is disposed to face a spouted fluidized bed, wherein classifying gas is introduced through the dropping port at a classifying flow velocity which is selected to be different from a flow velocity of gas to be introduced through the multiplicity of nozzle holes into the spouted fluidized bed granulating furnace, and means is provided therein to discharge the granulated raw material for cement while classifying the same by using the effect of the classifying gas which is introduced through the dropping port; and an injection chute for injecting the granulated raw material for cement from the

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

Abstract: A 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: An apparatus for manufacturing cement clinker is disclosed in which raw material powder of cement pre-heated by a pre-heating unit such as a suspension pre-heater and pre-calcined by a calciner is charged into a granulating furnace as to be granulated, thus-obtained granulated material is charged into a sintering furnace as to be sintered, and the sintered material is cooled and recovered by a cooling unit, the apparatus having a granulating furnace so that the granulating performance of the granulating furnace is improved.

Abstract: A cement kiln having a tire injection system. The tire injection system comprises an entrance chute having an outer end portion protruding outwardly of a wall of the kiln and an inner end portion which protrudes into the kiln. The entrance chute further is disposed such that it is positioned tangentially to the kiln wall. The entrance chute includes a gate assembly having a cam follower assembly and a pivotally mounted gate member. The cam follower assembly causes the gate member to be urged pivotally between open and closed positions in response to movement of the cam follower assembly over a cylindrical camming wall positioned at a predetermined location relative to the kiln. When the cam follower assembly has caused the gate member to open, a plurality of tires or other items forming a source of supplemental fuel are injected into the entrance chute by one or more external tire injecting apparatuses synchronized in operation to rotation of the kiln.

Abstract: The present invention is directed to a method and apparatus for controlling the kiln gas stream in a conventional long wet or dry process cement kiln. A portion of the kiln gas stream can be withdrawn from the rotary kiln vessel at a point upstream, relative to kiln gas flow of the chain system in the mineral drying zone. Alternatively, or in conjunction with bypass formation, the apparatus can be used to add tertiary air to the kiln gas stream to promote combustion efficiency downstream of the clinkering zone. Use of the present apparatus to form a kiln gas bypass stream enhances operating efficiencies of long kilns by reducing dust loss, by facilitating isolation of high alkali by-product streams, by reducing alkali content of collected kiln dust, by increasing energy efficiency of long kiln operation, and by allowing greater overall control in the cement manufacturing process.

Abstract: An equipment for precalcining any mineral materials whatsoever comprising a precalciner consisting of a combustion chamber communicating through a passage-way with a reaction chamber itself communicating via a duct with a separation cyclone, the reaction chamber being fed with smokes issuing from a firing furnace and three ducts feeding with hot air issuing from a cooler the combustion chamber, a voluted casing at the level of a burner and said duct, respectively, the equipment in particular permitting the manufacture of cement clinker while greatly minimizing the emission of nitrogen oxides.

Abstract: An inlet for a rotary kiln comprises a plurality of arcuate segments supported adjacent the inlet opening of the kiln to form a trough protruding through the inlet opening. Each of the segments is hollow and has an opening through which a cooling medium may be introduced.

Abstract: An incinerator is described which includes a cylindrical rotary furnace slightly inclined downwardly in its longitudinal direction for combusting material introduced into an entrance, a cylindrical housing for housing the furnace and a secondary combustor connected with an exit of the furnace. Partition plates are placed in an annular space between the housing and the furnace for defining a combustion air introduction zone below the furnace and recirculated gas introduction zone above the combustion air introduction zone. A gas recirculation duct extends from the secondary combustor to the furnace housing for introducing a portion of the gas flow discharged from the secondary combustor into the recirculated gas introduction zone. An external air flow is introduced to the combustion air introduction zone. The recirculated gas lowers the,temperature of the furnace and this results in reduced NOx generation.

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 method and apparatus for treating the exhaust gases of a combustion process, the exhaust gases comprising in part condensable or solidifiable particulate matter and residual hazardous organic compounds and emanating from the combustion process at a first temperature, by heating a portion of the exhaust gases using a heating means within a bypass means to a second temperature higher than the first temperature, maintaining the heated exhaust gases within the bypass means at the second temperature for a time sufficient to render the desired poriton of the residual hazardous organic compounds harmless, and then cooling the heated exhaust gases using a quench means within the bypass means to a third temperature lower than the first temperature in a period of time short enough to prevent the condensable or solidifiable particulate matter from condensing or solidifying on and adhering to the bypass means.

Abstract: An equipment for precalcining any mineral materials whatsoever comprising a precalciner consisting of a combustion chamber communicating through a passage-way with a reaction chamber itself communicating via a duct with a separation cyclone, the reaction chamber being fed with smokes issuing from a firing furnace and three ducts feeding with hot air issuing from a cooler the combustion chamber, a voluted casing at the level of a burner and said duct, respectively, the equipment in particular permitting the manufacture of cement clinker while greatly minimizing the emission of nitrogen oxides.

Abstract: In a generally known cement kiln plant which incorporates a preheater (1), a calciner (2) having a separation cyclone (3), a rotary kiln (4) and a clinker cooler (5), a decomposition chamber (10) is additionally installed for incineration of waste. Waste is introduced into the chamber at a location (12) and decomposed in the chamber by the heat from calcined raw meal which is conveyed to the chamber from the separation cyclone (3) of the calciner via a splitting gate (13) and a pipeline (14). Gaseous products are conveyed to the calciner (2) and burned there, whereas noncombustible by-products are discharged via an outlet (15) of the chamber (10). By utilizing the heat from preheated or calcined raw meal instead of, for example, hot exhaust gases to incinerate waste, any disturbance of the draught conditions of the cement kiln plant can be avoided, and the overall control of the calcining process is improved.

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: 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: In cement clinker production lines having calcinator connected upstream of the rotary kiln and equipped with a second firing, in order that the most complete possible burnup or residual burnup, favorable from the standpoint of thermal economy, of uncombusted fuel constituents such as, for example, CO and/or uncombusted residual carbon be enabled in the calcinator, and indeed in the case of calcinators without, but in particular with, a device for the reduction of the NO.sub.

Abstract: A dryer assembly dries waste materials to a predetermined moisture level. The dryer includes a drum having an inlet where waste materials and hot gasses are simultaneously introduced, and an outlet where dried materials and hot vapors are transferred out of the dryer. The drum presents a plurality of preheat baffles in which the material is heated by but does not contact the gasses, thereby avoiding premature combustion of the material. Baffle sections located downstream of preheat baffles uniformly distribute material downstream into a primary drying section of the drum, where the material is mixed with the gasses to uniformly dry the material to the predetermined moisture level. The primary drying section includes alternating baffle sections which dry the material and which recycle material that is not yet dried back into the preceding baffle sections, respectively.

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 method and arrangement for reducing the circulation of salts in a cement kiln in which a raw meal heat exchanger feeds material to the kiln. A partial gas stream charged with harmful substances is removed from the kiln through a bypass conduit. The partial gas stream is subjected to a multi-stage process of removing dust. This process includes passing the partial gas stream through a first dust separating stage, followed by returning an uncooled dust component of the partial gas stream to the kiln and cooling the remaining portion of the partial gas stream. The cooled remaining portion of the partial gas stream is subjected to a further dust separating process, and thereafter passed through a further bypass conduit to a location of the raw meal exchanger, which location has a temperature at approximately the same level as the temperature of the remaining portion of the partial gas stream entering the further bypass conduit following the further dust separating process.

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 particles, 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 c

Abstract: Apparatus, and a method for using the apparatus, for stripping solid material containing at least one volatile organic compound (VOC). The apparatus is provided with a dryer having a heat source to heat the VOC-containing material to a first temperature, hot enough to volatilize the VOC, but below the cracking temperature of the VOC. The VOC in the dryer is volatilized to form VOC gases. A means for combusting the VOC gases (e.g. a kiln) heats the VOC gases with excess air to a second temperature, hot enough to destroy the organics in the VOC gases. Simultaneously the combustion means preferably can be used to treat a kiln processable material to form a desired product. The kiln includes means for feeding the kiln processable material to the heating chamber, means for cooling and recovering the desired product, and means for providing heat for the VOC dryer. The apparatus also includes a conduit for conducting the gases containing VOC from the dryer to the kiln.

Abstract: A process and apparatus to treat powdered minerals placed in gaseous suspension by thermal exchange. The process includes the steps of preheating the minerals to be treated by the exhaust gas from a furnace. The minerals are then treated in the furnace. The minerals are then cooled with a stream of air prior to introducing the stream of air into the furnace. The furnace exhaust gases are filtered before being released into the atmosphere. A majority of the filtrate is mixed with the minerals leaving the furnace. The remainder of the filtrate is placed in suspension in a current of air diverted from the current of warm air which cools the minerals leaving the furnace. The remainder of the filtrate is separated from the air. The remainder of the filtrate is then mixed with the treated minerals and at least partially cooled. The diverted air is mixed with the furnace exhaust gases.

Abstract: The processor is of the type incorporating horizontal, concentric, co-extensive inner and outer tubular members which rotate together. The processor is modified in the following respects:The front end of the inner tubular member is circumferentially corrugated and may be provided in the form of a plurality of parallel tubes arranged in a ring array, to thereby increase the shell area to promote heat transfer through the tube walls;Means are provided for interconnecting the tubular members, which means can accommodate differing rates of thermal expansion and;a rock recycle tube assembly is provided to recover oversize material leaving the corrugated portion of the inner tubular member and reject it from the processor.

Abstract: A method and apparatus for heat treatment of lime mud comprises drying of the lime mud to be introduced into the lime reburning kiln in a pneumatic dryer by means of flue gases discharged from the lime reburning kiln in order to regenerate the lime content of the lime mud. From a drying filter, the lime mud thickened to a dry solids content of over 75%, preferably to 80%, is introduced into a feed chamber through which an adjustment portion of the flue gas is conducted. Depending on the gas amount, 100% or less of the lime mud is entrained with the gas into the dryer, the remaining portion falling into the lower section of the feed chamber, wherefrom it is further transferred into the lime reburning kiln.

Abstract: An apparatus for preheating a granular material having a suspension preheater including a plurality of stages of cyclones arranged above a calcination furnace such that the granular material is preheated by waste gas from the calcination furnace as the granular material passes through the suspension preheater. The apparatus has a precalciner of fluidized-bed type or spouted-bed type connected, in place of a duct used in conventional apparatus, between a collecting cyclone directly connected to be calcination furnace and a first cyclone constituting the most downstream stage.

Abstract: A drying and mixing plant for producing a bituminous paving mixture comprises a drying and mixing drum (10) which is supported by a hydraulic cylinder (16) or other lifting means so that the inclination of the drum axis may be altered. By choosing a suitably small angle of inclination so that the drum inclines downwardly towards its outlet end, the plant may be used for continuous operation, so-called drum-mixing. Aggregates and other components may then be supplied continuously to the inlet end of the drum from silos (18), through a center intake (24) from another source (25) and binder such as bitumen may be supplied through a supply tube (58). Finished paving mixture is continuously discharged from the outlet end of the drum and passed to a product silo (28) via a conveyor (27).

Abstract: Both aluminum scrap covered with a volatile coating and a heated airstream having a low oxygen content pass through a kiln where the airstream causes the coating to volatilize. The temperature of the airstream, where it enters the kiln, is maintained essentially constant, slightly below the melting temperature of the aluminum, and likewise the temperature of the airstream is maintained essentially constant where the airstream leaves the kiln, this being achieved by varying the mass flow of the airstream to compensate for variances in the nature and mass of the aluminum scrap within the kiln. Beyond the kiln the airstream enters an afterburner where it is heated in the presence of sufficient oxygen to effect combustion of the volatile components of the coating. The airstream then passes through a heat exchanger and back to the kiln. The mass flow within the kiln is controlled by diverting some of the airstream from the heat exchanger or by varying the speed of the fan which creates the airstream.

Abstract: The device comprises a drum drier with parallel streams (1) fed with recycled materials and a drum drier and countercurrent mixer (2) fed with virgin aggregates at its entry end (2a). The exit end (1b) of the drum with parallel streams (1) through which the dried and preheated recycled materials leave is connected to a ring (26) for introducing materials through the side wall of the countercurrent drum (2) through a chute for transferring the recycled materials. The ring (26) for introducing the recycled materials opens into a recycling and mixing zone (23) situated in the countercurrent drum (2) around the body of the burner (10), between the flame zone (22) and the mixing zone (24). The dried and heated recycled materials (8) are transferred continuously into the recycling zone (23) of the countercurrent drum (2).

Abstract: By a method for heat treatment of pulverous material, e.g. burning of lime, the lime is first preheated by means of exit gas in a preheater (1, 2, 3) and subsequently burnt in a calciner (4, 14), after which the burnt lime is cooled in a cooler (6, 7).In order to be able to alter the reactivity of the finish-burnt lime, the calciner is divided into two chambers, namely a first chamber (4) in which the lime is burnt at, e.g. 1050.degree. C. and a second chamber (14) in which a larger or smaller portion of the lime is further burnt at a higher temperature, e.g. 1300.degree. C.By means of a splitting gate (16) in the outlet from a separation cyclone (5) for the calciner (4, 14), it is possible to determine the size of the portion of lime which should be exposed to the higher burning temperature in the second calciner chamber (14) and consequently to predetermine the reactivity of the finish-burnt lime.

Abstract: In a method and an apparatus for the manufacture of clinker of mineral raw materials, such as cement clinker, according to the wet process and ensuring an almost complete absorption of the SO.sub.2 -emission in the kiln gases from a kiln, such as a rotary kiln working according to this process, the wet process is converted into a semi-dry process in feeding the wet ground raw materials (6, 7) together with a raw mix component such as flyash (5) and/or precipitated filter dust (18, 20) into gas suspension drying unit (4) mounted--seen in the direction of movement of the kiln gases--after a kiln (1) and heated with kiln gases for creating a gas/material suspension in the drying unit (4) thereby preheating and drying the wet raw materials before their returning via an overflow bin (11) and a duct (14) to the kiln inlet (2) and their further treatment in the kiln (1) and thereby simultaneously through an SO.sub.2 adsorption by the dry particles in the unit (4) ensuring the cleansing of the kiln gases.

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.

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 process for treating high sulfur petroleum coke to inhibit puffing is disclosed wherein particles of the petroleum coke are contacted with a compound containing an alkali or alkaline earth metal selected from the group consisting of sodium, potassium, calcium and magnesium, at an elevated temperature above that at which the alkali or alkaline earth metal compound begins to react with carbon, but below the temperature at which the coke particles would begin to puff in the absence of the compound. The coke particles are maintained at an elevated temperature for a sufficient period of time to permit the reaction to proceed and allow products of reaction to penetrate into the particles and form an alkali-or alkaline-earth-metal-containing deposit throughout the mass of the particles; and then cooling the so-treated coke particles.

Abstract: In the heat treatment of lime mud, the lime mud to be introduced to a lime reburning kiln is dried in a penumatic drier by flue gases from the lime reburning kiln in order to regenerate the lime contained in the mud. Prior to drying, the lime mud is thickened in a drying filter to a dry solids content of over 75%, preferably to approximately 80%. In this way, the lime reburning kiln can be made approximately 30% shorter than conventional kilns, and the apparatus is simpler than the conventional apparatus provided with a pneumatic drier.