Abstract: The invention in its various embodiments includes an apparatus and a method for improving combustion in a cement kiln system. The apparatus in one embodiment includes a precalciner and an oxygen source coupled to the precalciner. The method in one embodiment includes introducing oxygen into the precalciner of a cement kiln system.

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: Method and apparatus to recover energy from waste by means of combustion of such waste in industrial furnaces, particularly of the rotary type, that has an external calciner, feeding such waste into the tertiary air duct of the calciner and burning the waste inside the duct itself, to efficiently make use of the energy produced by such combustion, as a contribution of the total cost of fuel necessary to operate the industrial furnace. The method and apparatus permit the elimination of hazardous wastes that are efficiently disassociated when burned sufficiently to produce effluents that are typically non-toxic, producing greatly reduced or even no atmospheric pollution nor environmental damage.

Abstract: Cement clinker production apparatus having a precalcination stage connected upstream of a rotary kiln, in which precalcination stage a CO-containing reduction zone in the rotary kiln off-gas duct is employed for the purpose of reducing the pollutant NOx. In order to make certain that the quantitative ratio of O2 in the rotary kiln off-gas to fuel admitted by a deNOx burner, and thus control the effectiveness of NOx reduction, a pivoting throttle valve (33) is positioned in the precalcination stage to control the quantity of rotary kiln off-gas and thus the O2 content in the kiln off-gas. The throttle valve (33) is positioned in the rotary kiln off-gas duct (15) above the deNOx burner (19), above the raw meal inlet (13), and before the confluence of the tertiary air substream with the rotary kiln off gas.

Abstract: A rotary kiln for calcination of light aggregate cement comprises a calcination kiln body, a heavy-oil combustion device, and a cooling device, wherein the calcination kiln body is formed in a U-turn for saving construction site and is composed of a feeding entrance at its upmost end, a product exit at the lowest end, and a plurality of revolving segments varied in caliber by segment so as to raise the calcination efficiency, save construction expenditure, and meet environment requirements.

Abstract: An apparatus and process for fabricating tubing used in the making of chalcogenide fibers. The apparatus features a three-sectioned melt/spin ampoule that allows for fabricating the chalcogenide tubing without introducing impurities and contaminants, in a self-contained apparatus.

Abstract: Cement clinker is produced using high sulfur fuels by combusting high sulfur fuel within a kiln. The feed material is introduced at an inlet of preheater of the kiln and is sintered by the combusting fuel to form sintered material. The sintered material is cooled to form cement clinker. The production of the sintered material is controlled by measuring the sulfur content in the cement clinker and using that measurement to control the concentration of oxygen at the reaction and sintering zone of the 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: A drying and mixing plant is provided comprising a tapered inner drum (1) and an oppositely tapered outer drum (4) attached together concentrically and rotated as a unit. A burner (37) directs a hot air stream into the small end (2) of the inner drum (1). Material is fed into the small end of the inner drum, where impellers (40) lift it and drop it into the hot air stream and move the material through the inner drum (1) aided by the downward taper of the inner drum. The material exits the inner drum and enters the outer drum (4) where an additive material is introduced and mixed with the material (42) as both move through the chamber (28) between the inner and outer drums to a material outlet. The receiving end (5) of the outer drum (4) is enclosed in a shroud (12), therefore the air stream is directed through the chamber (28) between the drums, the chamber having an expanding cross section which slows the air down allowing fines to precipitate out.

Abstract: A method and apparatus for controlling the combustion of fuel modules charged into a preheater or precalciner kiln above the transition shelf, typically into the riser duct, is described. The apparatus includes a sensor for providing signals indicative of the status in the region of combustion of the fuel modules, and a controller for a fuel module feed mechanism is provided to receive signals indicative of the status of the combustion region and adjust the rate of delivery of the fuel module into the combustion region responsive to the sensed conditions in the combustion region.

Abstract: A method of disposing of undesirable chemical compounds in waste dust generated in a first kiln in the manufacture of cement clinker by using the dust and slag as the feedstock material to a second kiln, heating the feedstock material in an oxidizing atmosphere, and raising the heat sufficient to diffuse the waste dust and the slag to form a hydraulic product such as cement clinker and lime but insufficient to volatilize previously precipitated chemical compounds in the feedstock material.

Abstract: In this process the material is passed through a precalcination device equipped with at least one fuel injector at the outlet of which a fuel injection zone is formed, then the at least partially calcined material is passed into the rotary kiln which at its downstream end, is equipped with a primary combustion unit. At least one oxygen rich fluid with an oxygen concentration by volume higher than that of the products of combustion from the rotary kiln is injected near to the injection zone so that the oxygen rich fluid can supply from 1% to 40%, and preferably form 1 to 10% of the stoichiometric amount of oxygen needed for the combustion of the fuel injected by the injector.

Abstract: A kiln is provided with oxidant injection locations upstream of air blowers which blow air into the kiln. The addition of oxygen into the kiln increases the cooling capacity of a clinker cooler, and enhances combustion in the kiln.

Abstract: A cement production plant and method of regulating the flue gas temperature in a cement production plant. The cement production plant includes a kiln, a flue gas conditioning device, a mill and an electrostatic precipitator. The flue gas from the kiln is passed through the conditioning device. From there, the flue gas is conveyed either via the mill or directly to the electrostatic precipitator. The measurements are carried out in the flow path of the gas of the flue gas temperature before the electrostatic precipitator, and the water is supplied to the flue gas for cooling purposes in the conditioning device as a response to this temperature measurement, provided the temperature is too elevated.

Abstract: In order to create a calcinator preceding the rotary tubular kiln and equipped with secondary firings in which inert fuels that are difficult to ignite or, respectively, difficult to burn (secondary fuels) can be beneficially disposed of by burning for the purpose of calcination of the cement raw meal and a complete burn-out of CO gas strands and other fuel constituents, as well as an exhaust gas with low Nox, are nonetheless assured for cement clinker production lines, the tertiary air channel in the region of the calcination unit is fashioned as a combustion chamber that expands the channel cross-section and through which the suspension flows from bottom to top. Tertiary air having a torsion component as well as an easily ignitable fuel is centrally introduced at the lower end of the combustion chamber, whereby a high-temperature zone that extends centrally from bottom to top and has a hot core flame proceeds from this burning location.

Abstract: A rotating vacuum kiln and method 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 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: In order to create, for cement clinker production lines, a calcinator that is connected upstream from the rotary tubular kiln and is equipped with two firings, which enables on the one hand a high-grade calcinated raw meal and on the other hand an exhaust gas with very low NOx emissions, as well as a burning that is as complete as possible of remaining CO-containing NOx reduction zones, it is provided that a combustion point with sub-stoichiometric fuel combustion be arranged both in the rotary kiln exhaust gas ascending line and also in the cooler outgoing air line which form a first and section portion, respectively, of the calcinator and that downstream in a flow direction of the suspension, additional combustion air discharges into the calcinator which combustion air is branched off from the tertiary air line coming from the clinker cooler via at least one branch line.

Abstract: A system for removing volatile coatings from scrap aluminum, such as expended beverage cans, includes a kiln, a fan for generating an airstream, an afterburner for heating the airstream, and ducting for confining the airstream in a closed loop so that it circulates through the afterburner, the kiln and back to the fan in that order. The ducting includes a bypass duct into which a portion of the airstream is diverted at a diverter value, before being heated by the afterburner. This portion reenters the heated portion of the airstream downstream from the afterburner and serves to modulate the temperature of the airstream entering the kiln. Indeed, the diverter valve responds to a temperature sensor where the airstream enters the kiln and maintains the temperature at that location constant. That temperature is hot enough to volatilize coatings on the aluminum, yet not hot enough to melt the aluminum.

Abstract: Waste tires are disposed of in a cement-manufacturing or other mineral-burning process by introducing the tires into the hot gas stream at at least one point between the mineral-inlet end of a rotary kiln and the lowermost cyclone of an associated preheater system, e.g. into the gas stream within a precalciner vessel or riser duct, the tires being maintained in contact with the hot gas for a sufficient period to effect at least partial combustion of the tires. As an alternative, the tires may be introduced into a Lepol grate preheater.

Abstract: Emission of nitrogen oxides from a mineral-burning process, for example a cement-manufacturing process, is reduced by passing the exhaust gas from the rotary kiln in which the mineral raw materials are burnt to a combustion zone in which solid fuel elements, for example waste tyres, are maintained for a sufficient period and at a sufficient temperature for at least 30% by weight of the volatile combustible content of the solid fuel elements to be combusted, the combustion zone comprising at least one region in which the combustion of the solid fuel elements occurs under sub-stoichiometric conditions. The solid fuel elements may be introduced into the hot gas stream at at least one point between the mineral-inlet end of the rotary kiln and the lowermost cyclone of an associated preheater system, e.g. into the gas stream within a precalciner vessel or riser duct. Preferably, tertiary air from a clinker cooling apparatus is supplied downstream of the combustion zone (relative to the flow of kiln exhaust gas).

Abstract: A revolving drum containing a rolling element is provided that includes a member for the cleaning of the inner wall areas of the revolving drum which has at least two cleaning zones. The cleaning zones include projecting cleaning elements and lie in tandem in an axial direction of the revolving drum. They include a fastening apparatus disposed on a front end pointing toward the infeed side of the drum and include a revolving articulation by which the rolling element can be fastened to a non-revolving component of a head of the revolving drum. The cleaning zones comprise generated surfaces of the revolving drum which are at an angle to one another.

Abstract: An apparatus for producing cement clinker using a high sulfur fuel includes a wet rotary kiln, at least one sulfur analyzer, a controller, and a burner. The wet rotary kiln has a first end and a second end and processes a slurry of a raw material mixed with a certain quantity of coarse grinded high sulfur fuel received at the first end to produce cement clinker. The sulfur analyzer is produces a measure of the sulfur content of the cement clinker. The controller receives the measure from the sulfur analyzer and controls a concentration of oxygen in the kiln based on the measured sulfur content in the clinker end product. The burner is installed in the kiln at the second end and operates to burn a high sulfur fuel.

Abstract: A system for handling aqueous sludge to a combustor such that pollutant emissions associated with combustion operations, e.g., cement manufacturing, are reduced. Sludge is accumulated at a receiving site from where it is transported to a sludge conduit. The sludge is then introduced from the sludge conduit into a combustion apparatus at a point effective to reduce pollutant emissions produced by the combustion operation.

Abstract: A method of disposing of undesirable chemical compounds in waste dust generated in a first kiln in the manufacture of cement clinker by using the dust and slag as the feedstock material to a second kiln, heating the feedstock material in an oxidizing atmosphere, and raising the heat sufficient to diffuse the waste dust and the slag to form a hydraulic product such as cement clinker and lime but insufficient to volatilize previously precipitated chemical compounds in the feedstock material.

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: Cement clinker is produced using high sulfur fuels by combusting high sulfur fuel within a kiln. The feed material is introduced at an inlet of the kiln and is sintered by the combusting fuel to form sintered material. The sintered material is cooled to form cement clinker. The production of the sintered material is controlled by measuring the sulfur content in the cement clinker and using that measurement to control the concentration of oxygen at the inlet of the kiln. The fuel may contain up to 14% sulfur.

Abstract: A method and apparatus is described for environmentally sound usage of combustible hazardous waste as supplemental fuel in operating rotary cement kilns. The apparatus comprises an open port in the rotary vessel at a point where during cement kiln operation the in-process mineral material is in a calcining state and where kiln gas temperatures are sufficient to decompose volatile components of the waste fuel. A drop tube extending from the port into the kiln is provided to prevent in-process mineral from escaping through the port during rotation of the rotary vessel. Combustible solids are delivered through the port under the force of gravity and air is continuously drawn into the rotary vessel through the open port during kiln operation. The apparatus and method allow efficient usage of combustible solid waste as a supplemental fuel for cement kiln operation.

Abstract: Cement clinker is produced from powdered and fine-grained raw material by the use of a vertical stage cyclone preheater, a precalcinator, a kiln, and a cooler. The raw material is preheated by exhaust gases from the kiln and the cooler. Dust is filtered out of the exhaust gases, preheated, precalcined, and then burnt to cement clinker in a kiln. Downstream of the first preheater stage a relatively smaller part-quantity of the material is branched off and fed as a mixture jointly with the dust from the filter to the upper end of the precalcinator. This mixture passes through the precalcinator from top to bottom co-current with combustion air and with fuel for precalcination and then is delivered to the kiln inlet.

Abstract: Sulfur oxides are removed from a preheater waste gas stream by reacting the sulfur oxides with lime recovered from the off gas stream in a calcining furnace. The method is particularly adaptable for use in a cement manufacturing plant wherein the sulfur dioxides in the waste gases result from the combustion of fossil fuels used for process heat.

Abstract: A cement plant for the production of cement clinker from cement raw meal has a flat plate shaped control element for distributing and/or transporting-feeding a stream of hot flour-like material which is subjected to severe thermochemical and abrasive ware. the service life of the control element is greatly increased by constructing it as a hollow body (19, 22) through which coolant flows from at least one inlet opening to at least one discharge opening.

Abstract: Waste tires are disposed of in a cement-manufacturing or other mineral-burning process by introducing the tires into the hot gas stream at at least one point between the mineral-inlet end of a rotary kiln and the lowermost cyclone of an associated preheater system, e.g. into the gas stream within a precalciner vessel or riser duct, the tires being maintained in contact with the hot gas for a sufficient period to effect at least partial combustion of the tires. As an alternative, the tires may be introduced into a Lepol grate preheater.

Abstract: A method and apparatus for supplying lime sludge to a rotary kiln guides the flow of the lime sludge into the kiln, and the flow of flue gases out of the kiln, in distinct paths so that contact between the lime sludge entering the kiln and flue gases exiting the kiln is substantially prevented. This is typically accomplished by providing a general horizontal tubular duct interiorly of the kiln first end and extending into a substantially vertical flue gas conduit with an annular chamber defined between an outer surface of the tubular duct and an inner surface of an inlet to the first end of the rotary kiln. The lime sludge is introduced into the annular chamber. Spiral feeding blades are preferably provided on the outer surface of the tubular duct and the duct rotates with the rotary kiln so that the spiral feeding blades engage the lime sludge and move it toward the kiln. The lime sludge is preferably dried before it is fed into the annular chamber.

Abstract: A self-contained calcination plant is enclosed in a feed-storage silo. The plant consists of a vertical reactor, a separation cyclone and a pair of heat exchangers connected by appropriate piping and immersed in the feed material stored in powdery form in the silo. A positive displacement blower creates an air stream that is preheated in one of the heat exchangers and fed in part to a gas burner and in part to a feed pipe at the bottom of the reactor. The feed material is kept in a fluidized state in the silo by air heated in the other heat exchanger and blown upward from the bottom of the storage compartment, from where the material is dropped into the feed pipe through rotary valves prior to injection into the reactor. The feed pipe is connected tangentially to the reactor so as to produce an upward swirling flow around the burner's flame.

Abstract: There is disclosed a method for reducing the NOx emission from a kiln plant for heat treatment of raw materials, in which kiln plant fuel can be fired in at least three zones an amount c of fuel is burned, in a second of these zones an amount b of fuel is burned and to this second zone the NO containing exhaust gases from the other at least two zones are also fed. In the rest of these at least three zones an amount a of fuel is burned and at least a part of the raw materials are fed to these zones together with an oxygen containing gas. The total amount of fuel, b+a, burned in the second and in the last zones is determined by the need for treatment of the raw materials. When the kiln plant is used for manufacturing cement clinker the heat treatment consists of preheating, calcining, sintering and cooling of the mineral raw materials.

Abstract: The present invention relates to a plant for manufacturing cement clinker. The plant consists of a preheater, a calciner in which the raw material is calcined at a temperature of more than 800.degree. C. and where fuel and oxygen-containing gas are fed to the lowermost zone of the calciner, and a kiln. The object of the invention is to provide a plant for manufacturing cement in which it is possible to bum lumpy fuel in a calciner, while simultaneously maintaining the possibility of increasing the time of retention and possibly the temperature of the material being fed to the lowermost zone in the calciner. This object is achieved according to the invention in that the calciner is provided with a fixed bottom (27) allowing combustible material fed to the calciner to be deposited on the bottom and in that oxygen-containing gas is fed horizontally to the calciner through openings in the lowermost zone of the calciner.

Abstract: A method and apparatus is provided for use in cement clinker production apparatuses, particularly those with a short rotary tubular kiln, in which pollutant containing raw meals are utilized, wherein a bypass vent or gas sub-vent, exhausts a sub-stream of the rotary kiln exhaust. It is proposed to introduce meal or processing dust as condensation nuclei into the upper region of the kiln inlet chamber, these nuclei being entrained by the vented gas sub-stream. This vented gas sub-stream is subsequently further cooled by the introduction of water and/or cool air prior to its de-dusting in a dust trap.

Abstract: An apparatus for manufacturing cement clinker is disclosed in which raw material powder of cement pre-heated and partially pre-calcined by a pre-heating unit such as a suspension pre-heater (or a provided pre-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: The carbonizing furnace of the present invention is capable of effectively making a large amount of carbides and reducing manufacturing cost and maintenance cost. The carbonizing furnace includes a furnace proper being formed into a cylindrical shape, the furnace proper having a first end section, to which a combustible raw material is supplied, and a second end section, from which a carbide is discharged; a spiral member for conveying the raw material from the first end section to the second end thereof; and a burner for burning the raw material to make the carbide, the burner burns the raw material in the second end section whereby the raw material is carbonized therein, wherein a surface of the raw material is coated with an inorganic binder.

Abstract: A soil remediation system having apparatus for decontaminating particulate matter or dust entrained in and exhausted with a hot gas stream from a rotary drum wherein the particulate matter is subjected to heat-loss through an outer cylindrical wall of the drum. The system includes an inclined drum having a burner arrangement for directing a flame and hot gas stream into and axially through the drum ro remediate soil being processed through the drum, and dust decontamination apparatus including a fixed sleeve concentric with a downstream end of the drum such that an annular cavity is formed between the sleeve and the drum, and a filtering arrangement adapted to receive the hot gas stream as the hot gas stream is exhausted from the drum and to remove particulate matter entrained therein.

Abstract: A method of removing sulphur dioxide from exhaust gases generated in the production of cement wherein cement raw meal is preheated, ground, and burned in a kiln to form cement clinker which subsequently is cooled and ground. Grinding of the clinker is performed in the presence of preheater exhaust gases containing sulphur dioxide, the cement particles absorbing sulphur dioxide from such exhaust gases.

Abstract: The invention relates to a method for heat treatment of fine calcium carbonate bearing material comprising preheating fine material containing a coarse and a fine fraction. The preheated material is delivered into a fluidized bed calcining means wherein the coarse fraction is calcined and the fine fraction is delivered by process air to an adjacent vertically arranged gas flash calciner furnace in which it is calcined.

Abstract: A preheating apparatus for particulate material includes a plurality of vertical chambers, a temperature sensor within each chamber and a particulate discharge mechanism. Each chamber is segregated from an adjacent chamber by a vertical wall and includes a material inlet for receiving particulate material, a material outlet for discharging particulate material, a gas inlet for receiving a gas, and a gas outlet for exhausting gas. The temperature sensor is located within a chamber so as to sense temperature of the gas being exhausted from each chamber. A particulate discharge mechanism discharges particulate material within each chamber through the material outlet, with a flow rate adjusted as a function of temperatures sensed by the temperature sensor. A method for preheating particulate material includes sensing temperature of the gas existing each chamber and adjusting a flow rate of the particulate material through each chamber as a function of sensed temperature of each chamber.

Abstract: A carbon reactivation apparatus has a fossil fuel kiln adjacent to a rotary dryer and flue gas from the kiln flows through the dryer co-currently with carbon particles to provide a more efficient process than previously known. The apparatus has a rotary kiln with a drum therein sloped downwards from a feed end to a discharge end, a furnace shell surrounding at least a portion of the drum with a fossil fuel heater and hot gases from within the shell heat the rotary kiln. A rotary dryer slopes downwards from an inlet end to an outlet end and carbon particles to be reactivated are fed into the inlet end. Ducting from the shell surrounding the drum of the rotary kiln extends to the inlet end of the rotary dryer for hot gases to flow along the dryer to the outlet end in the same direction as the carbon particles.

Abstract: Cement clinker is produced using high sulfur fuels by combusting high sulfur fuel within a kiln. The feed material is introduced at an inlet of the kiln and is sintered by the combusting fuel to form sintered material. The sintered material is cooled to form cement clinker. The production of the sintered material is controlled by measuring the sulfur content in the cement clinker and using that measurement to control the concentration of oxygen at the inlet of the kiln.

Abstract: A cement clinker manufacturing installation a rotary kiln (10) having secondary firing and a grate cooler (16) with a high degree of heat recuperation. Instead of placing the grate cooler (16) in-line with the rotary kiln (10), the grate cooler (16) is positioned with its clinker transport direction (16a) transverse to the longitudinal axis of the rotary kiln (10). This angular positioning of the grate cooler (16) permits a discharge of hot air from the grate cooler as combustion air for the secondary firing of the calcination state by way of a discharge opening (20 or 21) on the lateral half of the kiln discharge housing (11) in which the beginning of the recuperation zone of the grate surface (15) of the grate cooler (16) is located. Thus somewhat cooler secondary air (18) flows into the rotary kiln (16) thereby avoiding excessively high temperatures at the rotary kiln discharge without reduction in overall thermal efficiency of the cement plant.

Abstract: A preheater or precalciner kiln is modified to feed solid fuel into a riser duct of the kiln to enable efficient environmentally sound use of solid waste-derived fuel. The modified kiln includes a solid fuel delivery port in the riser duct, a fuel feeder device for feeding solid fuel through the delivery port, and a fuel suspension device for holding the solid fuel for combustion in a fixed position in the kiln gas stream.

Abstract: An apparatus for sintering a cement clinker in which preheated powdered raw materials are granulated and sintered in a single fluidized bed granulating and sintering furnace. The apparatus includes a first classifying station having a discharging grooved portion extending from the fluidized bed furnace to an opening in a radial direction and communicating with a gas distributor. The space above the discharging grooved portion diverges from the opening to a fluidized bed upstream of the gas distributor so that the total velocity of air blown through the opening and from nozzles in the discharging groove is constant. A second classifying station is in communication with the opening for blowing back small particles to the fluidized bed. In a third classifying station, a discharge chute is connected to a fluidized bed cooling unit for quenching granulated and sintered clinker while small particles are blown back to the granulating and sintering furnace.

Abstract: A preheating apparatus for particulate material includes a plurality of vertical chambers, a temperature sensor within each chamber and a particulate discharge mechanism. Each chamber is segregated from an adjacent chamber by a vertical wall and includes a material inlet for receiving particulate material, a material outlet for discharging particulate material, a gas inlet for receiving a gas, and a gas outlet for exhausting gas. The temperature sensor is located within a chamber so as to sense temperature of the gas being exhausted from each chamber. A particulate discharge mechanism discharges particulate material within each chamber through the material outlet, with a flow rate adjusted as a function of temperatures sensed by the temperature sensor. A method for preheating particulate material includes sensing temperature of the gas existing each chamber and adjusting a flow rate of the particulate material through each chamber as a function of sensed temperature of each chamber.

Abstract: A description is given of a plant for heat treatment of lumpy material, such as limestone, other carbonate materials, cement raw materials, or the like. The plant comprises a preheating zone, a burning zone, and connecting means which connect the material outlet of the preheating zone to the material inlet of the burning zone. A separating device is provided as a part of the connecting means and consists of a duct through which a gas stream can be induced to flow from below and upwards. On entry into the separating duct at the top of the duct, the preheated material will be dispersed in the counterflowing gas stream, whereby the material is divided into a fine fraction which suspended in the gas can be discharged via the discharge means provided at the upper end of the duct, and a fall-through coarse fraction which is normal manner can be fed via a connecting means to the material inlet of the burning zone.

Abstract: This invention relates to a a vertical shaft kiln (VSK) useful for manufacturing cement and other allied products, which comprises a rotary nodule feeder for feeding the raw materials, fitted above the kiln bed for uniform distribution of nodules of the raw materials, an air blower being placed at the base of the kiln for feeding air through a duct to a common air header having a plurality of outlet air ducts, the air duct being connected to an air cone placed inside an armoured shell of the VSK, the said air cone being provided with a grate assembly having a plurality of peripheral air slots, the air duct being connected to an air box placed above the said armoured shell, the said air box having perforations on the inside vertical wall, the air duct being connected to an air header having air entry nozzles placed in such a manner so as to supply air just below the sintering zone of the VSK, the air duct being connected to the chimney of the VSK, the said chimney being provided with a butterfly valve below th