Abstract: An aspect of the present invention provides an internal and the like. The internal is easily handled and is capable of yielding a satisfactory defoaming effect. An internal (50) is used in a fluidized bed reaction device (1), in which a first material and a second material are brought into contact with each other and reacted with each other. The internal (50) is attached to a ceiling part of the fluidized bed reaction device (1), and includes a plurality of chains (21).

Abstract: To provide a device for removing radioactive cesium from waste material containing radioactive cesium, doing so at low energy and in a dependable manner. The removal device 1 for radioactive cesium is provided with: a rotary kiln 41 which is provided with a burner 41b supplying from the kiln outlet an organic matter O3 contaminated with radioactive cesium, and an inorganic matter charging port 41a supplying from the kiln inlet inorganic matter S4 contaminated with radioactive cesium, and which is employed to burn the organic matter O3 together with the inorganic matter S4; and a recovery device cooling tower 51, a cyclone 52, a bag filter 53 for recovering cesium that has volatilized in the rotary kiln. A drying/crushing device (dryer 21, crusher 22) for drying and crushing the organic matter O1 prior to charging the radioactive cesium-contaminated organic matter to the rotary kiln can be provided.

Abstract: An object of the present invention is to separate CO2 gas generated in a cement-manufacturing facility in a high concentration and recover the CO2 gas. The present invention includes: feeding a cement material before calcination and a heat medium which has a particle diameter larger than that of the cement material and has been heated to the calcination temperature or higher in a medium-heating furnace (14), to a mixing calciner (12); and recovering the CO2 gas generated by the calcination of the cement material. The heat medium circulates between the medium-heating furnace and the mixing calciner. Another aspect of the present invention includes: feeding a cement material before calcination to a regenerative calciner (112) which has been heated to the calcination temperature or higher and has stored heat therein; and recovering the CO2 gas generated by the calcination of the cement material.

Abstract: The present invention provides a system and a process for preparing activated carbon from fly ash. The system of the present invention comprises a flotation system and a carbonization system. The present invention has the following advantages. Firstly, since a fuel gas-flue gas loop structure is arranged, the combustible fuel gas produced in carbonization process enters the combustion means for combustion via this loop structure, and also via this loop structure, the high temperature flue gas generated by the combustion enters the carbonization furnace to heat up and carbonize the charcoal powder raw material within the carbonization furnace. Such a solution not only saves energy, but also prevents a substantial amount of combustible gas from being emitted to the atmosphere, thereby reducing environmental pollution. Secondly, since two cylinders are arranged in the carbonization furnace, the charcoal powder raw material in the inner cylinder enters the outer cylinder and then exits from the outer cylinder.

Abstract: A NOx suppression apparatus is configured for use with a burner that injects fuel into a stream of process air flowing into and through a rotary kiln. The apparatus comprises a premix injection system that forms a premix of fuel gas and air, and injects the premix into the stream of process air upstream of the burner port. This enables premix products of combustion to suppress the production of NOx by vitiating a combustion air portion of the process air before the combustion air portion combusts with fuel injected from the burner port.

Abstract: The invention relates to a process for manufacturing cement clinker in a plant having a cyclone preheater, a precalcination reactor, a rotary furnace and a clinker cooler. In the process, the flue gases from the furnace are conducted to the precalcination reactor, or even to the cyclone preheater. According to the invention, the precalcination reactor is fed with an oxygen-rich gas, the nitrogen content of which is less than 30%, constituting the sole oxygen source for said reactor, and a portion leaving the cyclone preheater is recycled into the plant so as to obtain a suitable flux necessary for suspending matter in said preheater, while the other portion, rich in carbon dioxide, is adapted for the purpose of a treatment for limiting the amount of carbon dioxide discharged into the atmosphere, such as particularly sequestration.

Abstract: A simple and economical process for rendering the fine fraction, from crushing of vehicles and iron scraps, capable of being used in the manufacture of bituminous or cement-based conglomerates as partial substitutes of quarry inerts. Subject of the invention is also a reactor suitable for carrying out the above process. FIG. 1 shows an embodiment of the reactor.

Abstract: This disclosure relates to carbonizing and activating carbonaceous material.

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: In a method for introducing waste substances and/or alternative fuels into a clinker production process, the raw materials, in the form of slurries or suspensions, are subjected to mechanical deagglomeration as a pumpable mass. The pumpable mass is ejected into risers, precalciners and/or the rotary tubular kiln. The device for carrying out the method is characterized by a tubular housing (1) including a rotor (2) mounted to be rotational substantially concentrically with the tube axis and driveable for rotation with blades (3) sweeping over the space between the rotor shaft and the housing wall, wherein a plurality of ducts and openings (6, 7, 11, 14) are connected to the shell of the tubular housing (1), and at least one duct (6) is arranged with the slurry supply and at least one duct is offset in the peripheral direction.

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: The invention relates to a washing household device, in particular to a clothes dryer, that includes an air-supply device which is arranged on a rear side area thereof and is provided with a closed self-contained cross-section flow channel.

Abstract: A fine dust removal system for a rotary lime kiln includes a preheater adjacent the charging end of the kiln and a housing adjacent to and communicating with kiln charging end, such that a major portion of not off-gases containing solid particulates are diverted to the preheater and a minor portion thereof directed into the housing. At least a portion of the solid particulates is separated from the hot off-gases in the housing, while the hot off-gases leaving the housing, after solid particulate removal, are directed into the preheater.

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 process and system for recovering waste heat from a kiln used for lime or cement production. The system unifies the kiln, a waste heat recovery and power generation circuit and a dry scrubber for scrubbing the pollutants from the kiln offgas. Essentially, the system employs the boiler component of the waste heat recovery and power generation circuit as a heat exchanger to recover the waste heat from the kiln, which is used to drive the steam turbines. The heat absorption from the latter stage lowers the temperature of the kiln offgas sufficiently for optimum performance from the scrubber. The presence of lime particles in the offgas effectively protects the boiler tube surfaces from corrosion which would occur at optimum scrubber temperatures, and subsequently provides the lime required as a scrubbing medium for the dry scrubber. Further, the efficient scrubbing allows for the use of any fuel for firing the kiln inclusive of high sulphur content compounds.

Abstract: A method is described for reducing NOx emissions and improving energy efficiency during mineral processing in a rotary kiln. The method comprises injection of air with high velocity/high kinetic energy into the kiln to reduce or eliminate stratification of kiln gases. The method can be applied to mix gases in a rotary kiln vessel or in a preheater/precalciner vessel.

Abstract: A method is described for reducing NOx emissions and improving energy efficiency during mineral processing in a rotary kiln. The method comprises injection of air with high velocity/high kinetic energy into the kiln to reduce or eliminate stratification of kiln gases. The method can be applied to mix gases in a rotary kiln vessel or in a preheater/precalciner vessel.

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: An apparatus for introducing a material into a kiln using low pressure air injection. In a preferred embodiment, that apparatus has a movable vessel that is movable between a collection position and a discharge position. The vessel has an open top and an open base. The open base supports a discharge gate that is movable between an open position and a closed position. In the closed position, the discharge gate prevents discharge of the material from the vessel while the vessel is moving from the collection position to the discharge position. An actuable vessel cover is adapted to cover the open top of the vessel when the vessel is at the discharge position. A low pressure air injection assembly, supported by the vessel cover, injects air into the vessel to force discharge of the material through the open base, the discharge gate and into the kiln.

Abstract: A method is described for reducing NOx emissions and improving energy efficiency during mineral processing in a rotary kiln. The method comprises injection of air with high velocity/high kinetic energy into the kiln to reduce or eliminate stratification of kiln gases. The method can be applied to mix gases in a rotary kiln vessel or in a preheater/precalciner vessel.

Abstract: A rotary kiln for pyroprocessing particulate material includes a cylindrical kiln shell supported for rotation about a longitudinal central axis. The kiln has a plurality of circumferentially spaced peripheral openings provided in the kiln shell near its exit end for discharging pyroprocessed particulate material therethrough. A raised grate disposed over each discharge opening has a generally convex geometric profile that projects into the interior of said kiln shell.

Abstract: A calcining system is operated in a substoichiometric mode for reducing nitrogen oxide generation and removing sulfur from materials to be processed by creating an oxygen deficient atmosphere. The calcining system includes a rotary kiln rotating on a slightly inclined horizontal axis. The rotary kiln has a feed end introducing material to be processed and a discharge end. A preheating/precalcining device is positioned adjacent the feed end such that the material passes through the device prior to entering the rotary kiln. A stationary hood surrounds the discharge end. A burner is supported by the stationary hood. The burner introduces combustible fuel and combustion air into the rotary kiln through the discharge end and operates in a substoichiometric mode. At least one air nozzle is located along the length of the rotary kiln. The air nozzle injects combustion air into the rotary kiln.

Abstract: A calcining system is operated in a substoichiometric mode for reducing nitrogen oxide generation and removing sulfur from materials to be processed by creating an oxygen deficient atmosphere. The calcining system includes a rotary kiln rotating on a slightly inclined horizontal axis. The rotary kiln has a feed end introducing material to be processed and a discharge end. A preheating/precalcining device is positioned adjacent the feed end such that the material passes through the device prior to entering the rotary kiln. A stationary hood surrounds the discharge end. A burner is supported by the stationary hood. The burner introduces combustible fuel and combustion air into the rotary kiln through the discharge end and operates in a substoichiometric mode. At least one air nozzle is located along the length of the rotary kiln. The air nozzle injects combustion air into the rotary kiln.

Abstract: A rotating vacuum kiln for heat treating solid particulate material under vacuum conditions uses a rotating refractory metal cylindrical vessel with a cool inlet zone, hot intermediate zone, and cool exit zone, with a first series of inner radiation shields provided at the hot intermediate zone adjacent to the cool inlet zone and a second series of inner radiation shields provided at the hot intermediate zone adjacent the cool exit zone to protect those two zones from the high temperatures in the hot intermediate zone. Heat for the hot intermediate zone of the cylindrical vessel is provided indirectly by electrical resistance heaters that surround the vessel and outer radiation shields are provided about the heaters to direct heat to the cylindrical vessel.

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 method for reducing emissions of a kiln including a feed end, the method includes operating the kiln and spraying a slurry inside the kiln at least five feet from the feed end. Additionally, the kiln includes a substantially tubular body including a bore therethrough. The body has a clinker end, a heat portion, and a feed portion. The kiln further includes a plurality of chains mounted within the bore at the feed portion, a heat source in flow communication with the heat portion, and a spray nozzle mounted in the feed portion away from the feed end.

Abstract: A multi-axis rotary seal system to provide a gas-tight seal between a stationary hood and the end of a rotating tube kiln comprises a stationary hood positioned at the end of the rotary tube and having extended therefrom, a fully flexible bellows attached at the other end to a structural ring which, in turn, is attached to a graphite ring, slidably pressed against a flange on the rotary tube to form an atmospheric seal. The structural ring is held to the stationary hood by multi-axis supports that allow movement of the ring in three axial directions. In operation, during expansion and contraction of the rotating tube and eccentricities of motion, the integrity of the slidable seal formed by the graphite ring against the mating surface of the tube flange, is maintained by a biasing device pressing the graphite ring and the tube flange together in slidable engagement.

Abstract: A rotary furnace includes a drum and a frame supporting the frame for rotation about a nominally horizontal rotational axis. The frame and the drum are supported for pivotal movement about a horizontal pivotal axis. A door supported on the frame normally closes the front end of the drum and is selectively pivotal to an open position to facilitate charging of the drum. The door includes a pouring door which is openable to facilitate discharge of molten material from the drum.

Abstract: A method or an arrangement for making the fired-material discharge stream from a rotary kiln more uniform upstream of a cooler is distinguished by the fact that at least some of the fired material is conveyed out of the coarse-material discharge region (5) toward the fine-material discharge region (4) and/or at least some of the fired material is conveyed out of the fine-material discharge region (5) toward the coarse-material discharge region (5) before it reaches the cooler.

Abstract: A method of burning tires in a horizontally rotating combuster includes the steps of loading the tires into a rotating combustion chamber through a traveling air lock and burning them until they are reduced to ash; enhancing combustion by tumbling the burning tires in a tapered rotating chamber while adding preheated draft air; controlling the intake draft air using thermal expansion of the rotary combustion chamber to activate the draft control valve; advancing the residual ash with each successive revolution of the combustion chamber by use of angled flights on the inner surface of the chamber to an afterburner for completion of the combustion and disposal of the ash.

Abstract: A method for automatized combustion of solid fuel in a combustion apparatus which comprises a burner with a device, which is rotatable about the center axis of the burner for stirring the fuel in the burner which is connected to a boiler and has a feeding-in opening for fuel in the rear end of the burner outside of the boiler and an outlet opening for completely or partly combusted flue gases in the front end of the burner which opens in a combustion chamber inside the boiler which comprises a convection unit, from which a hot water conduit extends, the combustion apparatus also including a fan provided to be driven by a second motor for blowing combustion air into the burner, and a fuel charge feeder for fuel provided to be driven by a third motor.

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 kiln adapted to recycle kiln dust includes a recycle dust pipe in fluid communication with an oxidant stream to increase the concentration of oxygen in the fluidized recycle dust before the recycle dust stream is directed into the kiln flame. Increasing the oxygen concentration in the recycle dust stream improves the efficiency of the recycling process. A supplemental fuel stream may be introduced into the recycle dust stream to provide an additional flame to preheat the recycle dust stream before the recycle dust stream is directed into the kiln flame.

Abstract: A discharge assembly for removing material from a hearth in a rotary hearth furnace including a discharge auger and a coolant spray. The discharge auger is positioned above the hearth of the rotary hearth furnace and includes a central shaft having at least one helical flight affixed to the exterior of the central shaft and the hood is disposed above the discharge auger. The coolant spray cools the discharge auger.

Abstract: A system and method for increasing the amount of oxygen in a kiln chamber is disclosed. The radial surface of a rotatable kiln is provided with at least one oxidant injection port extending through the radial surface into the kiln chamber. A cam is connected to the radial surface adjacent the oxidant injection port. A valve assembly including a valve chamber in fluid communication with an oxidant supply is mounted adjacent the kiln substantially in fixed spatial relation with the rotatable kiln body. The valve assembly includes a follower member adapted to contact a surface to the cam to actuate the valve assembly. Rotation of the kiln body brings the cam into contact with the follower member, thereby actuating the oxidant injection assembly, and injecting oxidant through the injection port into the kiln chamber.

Abstract: A vapor control apparatus including an endless rim, a stagnation plate and a cover having an exhaust port. The endless rim has a first edge engaging the cover, a second edge opposite the first edge, an interior region and an exterior region defined by the rim and the cover, and a flow passage from the interior region to the exterior region adjacent the cover. The exhaust port is in fluid communication with the interior region and the second edge is seatable on a wafer support. A stagnation plate is disposed in the interior region, defining a stagnant region intermediate the stagnation plate and the surface, and defining at least one flow path in fluid communication with the stagnant region and the interior region.

Abstract: A probe having a double-tubed structure is provided to communicate with a kiln exhaust gas flowing path. A part of kiln exhaust gas is extracted through an inner tube of the probe, while cooling gas is supplied to a fluid flowing path formed between the inner tube and an outer tube of the probe. The cooling gas is guided to flow into an inner area of a front end portion of the inner tube so as to form a mixing and quick cooling area at a front end portion of the probe, thereby rapidly cooling the extracted gas.

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: A burner apparatus uses fuel derived from waste resin. The burner includes a cylindrical body in combination with an oxygen supplier, which form an oxygen deficient atmosphere. While rotating the cylindrical body, a small portion of waste resin is partially combusted to generate heat energy and changes its form to finely divided particles. The heat energy is used for heating and gasifying a remaining larger portion of the waste resin. The produced gas particles are conveyed toward an outlet nozzle of the cylindrical body and are injected outwardly for complete combustion in air.

Abstract: A discharge assembly for removing material from a hearth in a rotary hearth furnace. The discharge assembly includes, in combination, a discharge auger and a fluid cooled hood. The discharge auger is positioned above the hearth of the rotary hearth furnace and includes a central shaft having at least one helical flight affixed to the exterior of the central shaft. The fluid cooled hood is disposed over the discharge auger to lower the temperature of the helical flights.

Abstract: A direct heat rotary calciner and method for providing improved thermal treatment of particulate material comprises a rotary tube having a plurality of screened apertures along the length thereof. Material to be treated is passed through the rotating tube and contacted during passage with a cross-flow of heated gases entering and leaving through the screened apertures. At least a portion of the internal wall of the tube may be provided with spiral flights to aid in the conveyance of the particulate material through the rotating tube.

Abstract: A closure mechanism (16) for controlling charging of material through a port into a rotary kiln such as a cement kiln comprises a first and second portion (24,26), and a passage (29) which communicates with the port (12) to enable material to pass into the kiln when the mechanism is open. The first portion (24) acts to prevent reactive material passing through the passage and the closure (26) acts to close the port when the mechanism is in a closed position. The mechanism is movable to enable material such as tires to pass into the kiln but helps prevent premature degradation of the material by the heat of the kiln when the mechanism is closed.

Abstract: A feeding apparatus for feeding whole tires into a cement kiln comprising a feed opening in the shell of the kiln, a passageway including a sleeve extending within and outside the kiln, an arcuate sector valve device for closing the passageway and timed to open so as to allow the tires to fall into the kiln through the passageway. The sector valve having an outer perforated wall and an inner wall, the perforated wall allowing ambient air to circulate between the outer and inner wall to keep the outer wall cool for contact with the tires. A transfer device is provided for transferring the tires onto the feeding apparatus wherein the transfer device includes fingers while the feeding apparatus includes a fork receiving tray interdigitated with the fingers to pick up the tires as the kiln rotates.

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: The present invention relates to a smoke and heat source recycling device for a tunnel kiln in order to prevent smoke pollution. It has an exhaust fan in the preheating zone, the exhaust fan absorbing heat from the preheating zone and delivering such heat to a heat energy adjustment zone and waste gas treatment system for treating pollutants such as coal dust. Heat in the dry zone is delivered into the exhaust duct through an exhaust collector. A and pollution controller detects the pollution and enters signal into an electronic control to control gates for exhaust gas to enter either a gas treatment system or to be emitted into the air through the chimney.

Abstract: A rotary kiln has a generally cylindrical housing centered on and extending along an axis inclined to the horizontal and having an upper upstream end and a lower downstream end and a drive that rotates the kiln about its axis. Particles to be heat-treated are fed into the housing at the upstream end and are extracted from the downstream end. A plurality of axially separate heat-exchange radiators fixed in the housing are connected axially in series and a fluent heat-exchange medium is flowed serially through the radiators from the downstream end of the housing to the upstream end of the housing.

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: A dehydration treatment apparatus for sludge wherein organic sludge and a modifying/setting agent are charged into a rotating drum and the sludge is dehydrated and dried. The apparatus comprises a rotating drum, a sludge charging hopper arranged on the inlet side of said rotating drum, a discharging screw arranged on the outlet side of the rotating drum, at least two rectangular blades that are projected from each of circular surfaces arranged toward the feeding direction from the inlet side of the inner circumferential surface of the rotating drum and are slanted downward at a prescribed angle toward the feeding direction, and an agitating/feeding means wherein the positions of the blades on the circular surfaces are made different stepwise successively in the direction of rotation toward the feeding direction so that sludge may be scraped up by the blades on the fore circular surface to be fed forward.

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.