Abstract: In a shaft furnace for burning limestone or similar raw materials, gaseous, liquid or solid fuels are supplied through fuel supply pipes to the burning zone of a furnace shaft. To permit the simultaneous supply of at least two different fuels, the fuel supply pipes are arranged as multiple fuel lances. The fuel lances extend inwardly from the shaft furnace wall through the preheating zone into the first part of the burning zone. The fuel lance is a double tube member made up of an inner tube laterally enclosed by an outer tube forming an inner fuel supply passageway and an outer annular fuel supply passageway. Two separate fuels can be introduced into the burning zone, one flowing through the inner passageway and the other through the outer annular passageway. The two different fuels can be supplied in varying proportions without any changeover operations.

Abstract: A method of and apparatus for recovering exhaust gas from a boiler 2 of a thermal electric power generating device 1 are disclosed. The exhaust gas from the boiler 2 is fed through a conduit 30 to a preheat section 21 of a powder raw material treating device 20. The heat of the exhaust gas is recovered as a heat source for preheating the powder raw material. The ash contained in the exhaust gas is recovered as part of the powder raw material at the preheat section. The sulfur oxides in the exhaust gas react with the desulfurizing component of the powder raw material at the preheat section, and its reaction product is recovered as part of the powder raw material.

Abstract: A method and mechanism for heat treating a pulverulent comminuted raw material in the process of making cement including preheating the material, passing the material through a first reaction zone, supplying a first fuel supply to the first zone for supplying thermal energy for carrying out the calcination reaction, separating the material from the hot gases received from the first reaction zone and delivering the material to a second reaction zone to which is supplied a second fuel supply for supplying thermal energy for the calcination reaction in the second zone and separating the material from the hot gases from the second zone and delivering the material to a sintering kiln and then passing it to a cooler with the air from the cooler supplied to support combustion in the first zone, and with the arrangement preferably arranged in two parallel flows with each flow path containing the preheater, and the reaction zones and separators with the material flows combining just as they enter the sintering zone.

Abstract: A method and apparatus for reducing the sulfur content and/or the SO.sub.2 emission in a system for calcining fine grained materials such as in the manufacture of cement utilizing a pre-calcining and a final calcining stage. The sulfur content of a process gas or of a material stream is determined and then is mixed with appropriate amounts of a dust or a raw meal in a reaction zone, the dust or raw meal containing sulfur bonding substances such as alkaline earth carbonates. The exhaust gas from which the sulfur compounds are removed by the sulfur bonding is separated from the sulfur containing solids and the exhaust gas and solids are removed from the calcining system.

Abstract: This disclosure relates to a rotary kiln for heating and calcining lime, waste, etc. and to a method of direct reduction of metal oxide using such a kiln. A cylindrical outer shell is mounted for rotation on its axis, and a stationary inner tube extends into the interior of the shell. Fuel and/or combustion air flow passages extend within the tube, and burner nozzles are supported by the tube and are connected to the passages. The tube is concentrically or eccentrically mounted adjacent the upper side of the space within the shell, thereby positioning the burner nozzles at the optimum positions.

Abstract: Method of operating a rotary calciner retrofitted from oil- or natural gas-firing to coal-firing, in which coal is burned in a coal furnace and the coal combustion gases are then heated further in a booster burner utilizing oil or natural gas, to raise the combustion gas temperature to permit processing of calcine at up to a design capacity rate.

Abstract: A method and improved kiln for calcining and sintering of lumpy materials which includes an arrangement for creating a cavity in the material being processed adjacent each burner units so that a solid fuel can be applied on a cavity surface of the material at each burner.

Abstract: An improved process and system for drying moist particulate carbonaceous materials. The invention has particular application to staged drying processes wherein the particulate material is entrained in one or more serially connect hot gas streams having a temperature above the degradation point of the carbonaceous material. The improvement includes providing contactors between the stages which intimately mix and contact the variously sized particles resulting in partial cooling of the smaller hot and dry particles and partial heating of the larger cool and relatively moist particles. The contactor may be provided by a rotating drum, moving bed, fixed bed or fluidized bed. The contactors prevent overheating of small particles during moisture removal and reduce hydrocarbon loss from small particle devolatilization.

Abstract: An apparatus that is designed to heat a flowable granular material up to an elevated temperature and cool the material back down to a temperature that is as close as possible to the temperature of the incoming material before exiting, where a substantial portion of the heat transferred in both heating the incoming material up and cooling the outgoing material back down is not being accomplished by outside heat sources and heat sinks, but rather by transferring heat from outgoing material to incoming material on a more or less direct basis. This is to be accomplished by an apparatus that is comprised of two coaxial cylinders rotating about their common axis whereby feed material enters and exits from one end, and a heat source is provided at the opposite end. Feed material enters into the inner chamber and travels towards the heat source.

Abstract: A method and apparatus for treating granular materials which require to be heated to drive off volatile constituents and which require to be cooled, for example foundry sand containing an organic binder. The method comprises the step of maintaining a mass of the material at a treatment temperature lying in the range 240.degree. C.-400.degree. C. for between four and thirty hours. The mass may be initially heated by virtue of a manufacturing process in which the mass has been previously used. Alternatively, the mass may be initially heated by a preheating step such as heating in a fluidized bed. Alternatively, the mass may be heated by being placed in heat transfer relationship with a second mass of the material which has been previously heated, for example, in a fluidized bed. Apparatus for performing the method is also disclosed.

Abstract: Coal is pretreated for a coking plant so that it is passed in two stages through two throughflow driers successively connected with one another, the driers are supplied with a heat carrier formed by a steam overheated to a temperature between 400.degree. and 600.degree. C., dust is removed from the steam after passing the throughflow driers, and the steam is heated after the dust removal in a heat exchange with a circulating gas of a coke dry cooler.

Abstract: In a process of producing cement, the ground raw material is de-acidified in a calcinator and is subsequently burnt in a kiln and before being de-acidified in the calcinator is subjected to a multi-stage heat exchange with exhaust gas streams from the kiln and from the calcinator in two parallel series of heat exchange stages. The stream of ground raw material is delivered from heat exchange stages of each of said series to respective heat exchange stages of the other of said series. In order to improve the thermal efficiency and to reduce the equipment expenditure, the exhaust gas stream from the kiln is caused to deliver heat to the ground raw material in an additional heat exchange stage, which directly precedes the calcinator in the flow path of the ground raw material, and the exhaust gas stream from the kiln is subsequently mixed with the exhaust gas stream from the calcinator. The resulting stream of mixed exhaust gases is uniformly distributed to the two series of heat exchange stages.

Abstract: In the production of cement, the ground raw material is de-acidified in a calcinator and subsequently burnt in a kiln and before being de-acidified in the calcinator is preheated by a multistage heat exchange with exhaust gas streams coming from the kiln and from the calcinator, respectively, and conducted in two parallel series of heat exchange stages. Up to the heat exchange stage which directly precedes the calcinator and receives the exhaust gas stream from the kiln, the stream of ground raw material is conducted from each heat exchange stage of one series to a heat exchange stage of the other series. In order to provide equal conditions in both series of exhaust gas-handling heat exchange stages, part of the hot exhaust gas stream from the calcinator is admixed to the hot exhaust gas stream from the kiln before or adjacent to that heat exchange stage which directly precedes the calcinator.

Abstract: In a method for continuously burning particles in a gas or oil heated vertical furnace in which the particles are charged from an uppermost part of the space, and the particles bed fluidized by a burning gas flow is formed in a vertically successive downward arrangement and then the burned particles are discharged out of the bottom of the furnace after cooling, the improvement comprises the steps of: providing the furnace with a plurality of downwardly vertically successive zone, including a precipitation zone of the particles at an uppermost part in the furnace, a lower upward flow velocity zone having low upward stream of the burning gas (referred to as "rich fluidized bed", hereinafter) and a higher upward flow velocity zone having high upward stream of the burning gas (referred to as "lean fluidized bed", hereinafter) underneath the precipitation zone wherein the lean fluidized bed is formed beneath and adjacent to the rich fluidized zone, and feeding the particles, burning them successively through the z

Abstract: A method of discharging material from a rotary furnace is disclosed, which method comprises the steps of feeding the material from a preheater into the rotary furnace under gastight conditions, subjecting the material to heat treatment within the rotary furnace, connecting the inlet port of a container to the discharge opening of the rotary furnace, discharging the material from the rotary furnace while maintaining gastight conditions, and thereafter detaching the container from the rotary furnace.

Abstract: In this process carbonaceous materials in a wide range of particles size are heat treated in a substantially vertical gravity retort through which heated gasses flow upwardly. The particles are graded by size and fed into the retort with the largest particles being inserted into an upper portion of the retort, and in preferred embodiments, with progressively smaller particles being inserted into progressively lower portions of the retort so that the residence time of each of the particles in the retort is substantially directly proportional to the size and mass of the particles. This process allows high throughput of the material while reducing the amount of entrained small particles which flow up with the heated gas, thus reducing pressure drop in the retort system.

Abstract: To permit the utilization of high-sulfur content solid fuels in the production of cement clinker in rotary kilns, the solid fuel is gasified and the gasified fuel is contacted with a fraction of the raw material used for the production of the cement clinker to desulfurize the gasified fuel, the desulfurized gasified fuel being delivered to a calcination stage and/or the rotary kiln for furnishing calories thereto.

Abstract: A method for thermally treating pulverulent material, i.e., keeping the material at a certain temperature, the treating temperature, in a desired period of time, in particular sintering, pulverulent material in a rotary kiln slightly inclined to the horizontal. The method is especially applicable for thermally treating materials which tend to become sticky at the treating temperature, in particular for sintering pulverulent materials, i.e., agglomerating these by heating without complete melting. However, the method is also useful for general thermal treatment where sintering is not intended, e.g., for burning Bauxite, Mesa and phosphate bearing ores. An example of a sintering process to which the invention is particularly applicable is the manufacture of cement clinker where the pulverulent material to be sintered is hot calcined cement raw meal. An apparatus for practicing the method of the present invention is also disclosed.

Abstract: A method for thermally treating pulverulent material, i.e., keeping the material at a certain temperature, the treating temperature, in a desired period of time, in particular sintering, pulverulent material in a cylindrical reaction chamber with an axis slightly inclined to the horizontal after the material has been heated to the treating temperature outside the reaction chamber suspended in a gas. The method is especially applicable for thermally treating materials which tend to become sticky at the treating temperature, in particular for sintering pulverulent materials, i.e., agglomerating these by heating without complete melting. However, the method is also useful for general thermal treatment where sintering is not intended, e.g., for burning Bauxite, Mesa and phosphate bearing ores. An example of a sintering process to which the invention is particularly applicable is the manufacturing of cement clinker where the pulverulent material to be sintered is hot calcined cement raw meal.

Abstract: A method is disclosed for treating granular or pulverous raw material in a kiln plant including a preheater stage, a precalciner stage and a separator stage coupled to one another. Precalcined material is separated after the separator stage into a first and second material flow. The first material flow is suspended in spent cooling air and fed to a reaction zone zone for burning and melting the material therein. The melted material is fed to a cyclone for separating smoke gases therefrom and thereafter to a rotating nodulization drum. The second material flow is also fed to the rotating nudulization drum and mixed therein with the melted material so as to avoid any sticking and clogging of the melt. A kiln for practicing the method of the present invention is also disclosed. In preferred alternative embodiments, the reaction chamber can be either a shaft-like chamber or a cyclone burner.

Abstract: In a process of producing cement, a powdered mixture of raw materials is de-acidified in a calcinator and subsequently burned in a kiln. Before de-acidification, the mixture is preheated in a plurality of heat exchange stages by the exhaust gases from the kiln and from the calcinator, which are passed through respective parallel series of the heat exchange stages, the powdered mixture being passed from heat exchange units of each series to associated heat exchange units of the other series. The heat efficiency of this process is improved by combining the exhaust gas streams from the kiln and from the calcinator coming from the parallel series of heat exchange stages, and then feeding the combined stream of exhaust gases to another heat exchange stage, which is the last stage in the flow path of the exhaust gases and to which the cold powdered mixture of raw materials is fed.

Abstract: Reduction of nitrogen oxide emissions from thermal incinerators is accomplished in installations for calcining solid carbonaceous materials such as petroleum coke and anthracite coal. A hot effluent gas stream containing hydrocarbon vapors and entrained carbonaceous solid particles is removed from the calciner, and means are provided to effect preliminary combustion of the hydrocarbon vapors but not the carbonaceous solid particles in the gas stream using substantially the stoichiometric amount of combustion air. The resultant gas that is substantially free of hydrocarbons and oxygen is introduced into the thermal incinerator, and combustion of the carbonaceous solid particles is effected with additional combustion air.

Abstract: The invention relates to a process and an installation for the heat-treatment of fine-grained material. Before the material is introduced into a precalcination zone, waste air from a cooling zone is divided into two component streams into which partial quantities of material coming from the two preheating zones are introduced. Separately measurable quantities of fuel are added to these two component streams before they are combined with one another. In this way, the material is maximally deacidified in the precalcination zone before it is introduced into the calcining zone without any danger of deposits being formed in the precalcination zone.

Abstract: A method of and apparatus for recovering exhaust gas from a boiler 2 of a thermal electric power generating device 1 are disclosed. The exhaust gas from the boiler 2 is fed through a conduit 30 to a preheat section 21 of a powder raw material treating device 20. The heat of the exhaust gas is recovered as a heat source for preheating the powder raw material. The ash contained in the exhaust gas is recovered as part of the powder raw material at the preheat section. The sulfur oxides in the exhaust gas react with the desulfurizing component of the power raw material at the preheat section, and its reaction product is recovered as part of the powder raw material.

Abstract: A kiln plant for burning a pulverous material such as cement, which includes a preheater string for preheating raw material and a precalciner for receiving preheated raw material, the precalciner being fired with solid fuel, and a disintegrator provided adjacent the precalciner. Within the disintegrator the solid fuel, preferably coal, is crushed and mixed with a portion of the preheated raw material before passage into the precalciner. The invention also relates to a unique method for firing in the precalcining zone of the invention kiln plant.

Abstract: Disclosed is a method for firing a kiln as well as a method for producing cement clinker in which pulverized coal is initially entrained in an airflow of about 2% of the theoretical amount of air needed to combust the coal and transport it to a burner. Supplemental primary air heated sufficiently to vaporize volatiles in the coal is mixed with the coal flow in a burner, discharged into the kiln and hence ignited. Secondary combustion air heated to between 800.degree. F. to 1650.degree. F. and more is added in the kiln to effect the substantially complete combustion of the pulverized coal in the kiln.

Abstract: A kiln plant for burning raw materials such as cement raw materials and the like includes a single-string, multi-stage suspension preheater, a suspension precalciner, a rotary kiln and a cooler. The single-string preheater includes at least a lowermost preheater stage and a penultimate preheater stage each having a gas flow inlet and outlet. The precalciner gas outlet is coupled to the gas inlet of the penultimate preheater stage. The gas outlet of the lowermost preheater stage is also coupled to the gas inlet of the penultimate preheater stage. The materials are precalcined in the precalciner solely by means of spent cooler air from the cooler while the materials are preheated in the lowermost preheater stage solely by means of kiln exhaust gases. The pressure drops arising in the two gas flows through the precalciner and the lowermost preheater stage are equalized before the union of the two gases flows entering the gas inlet of the penultimate preheater stage.

Abstract: A method and apparatus for roasting fine grained ores such as cement raw meal, lime, dolomite, gypsum, phosphate rock and the like. A suspension preheater consisting of a plurality of serially connected cyclone separators is utilized to preheat the raw material. A suspension type roasting furnace follows the suspension preheater which is, depending upon the material being treated, followed by either a rotary kiln for further heat treatment of the material or by a cooler for cooling the product. The apparatus includes an arrangement for recirculating a portion of the material which has passed through the roasting furnace back into the roasting furnace to increase the degree of roasting. An existing preheater, suspension type calciner, rotary kiln cement clinker producing plant can be converted to the method and apparatus by the addition of an appropriately located splash plate.

Abstract: The present invention is directed to a biomass gasifier combustor which operates by gasification and combustion of the biomass to produce a clean effluent gas which can be used directly for grain drying or other applications where thermal energy is required. This biomass gasifier combustor burns crop residue clean enough so that the combustion gases can be used directly for grain drying without the need for a heat exchanger to isolate the combustion gases from the drying air. The biomass gasifier combustor includes a screw feeder tube having a screw feeder disposed therein. The screw feeder forces the biomass into a first combustion chamber. Primary combustion of the biomass produces a first combustion gas. A venturi gas pump creates a negative pressure region in the gasifier, drawing the first combustion gas into a second combustion chamber.

Abstract: An improved process for heat-treating pellets in a pelletizing machine in which hot gases are generated and passed through a bed of pellets includes charging solid carbonaceous fuel onto the surface of the pellet bed and burning the carbonaceous fuel to generate at least a portion of the hot gases.

Abstract: A calcining combustor for the suspension preheater of a rotary kiln cement manufacturing plant having a cooler for the clinker comprises an upright furnace vessel having an outwardly spiraling gas exhaust duct at its upper end leading to a preheater gas/meal separator and a mixing portion at its lower end; an inlet for hot combustion air from the cooler into the mixing portion; an inlet for cement meal from the preheater into the mixing portion downstream from the combustion air inlet to entrain the meal in the rising combustion air; and burners for injecting fuel into the air/meal stream downstream from the meal inlet to calcine the meal by heat released by burning of the fuel with the combustion air.

Abstract: A method is disclosed for manufacturing pulverous or granular material in a plant supplied with raw material, for example, cement raw meal, including a kiln for burning the raw material to be treated therein, a cooler coupled after the kiln for cooling the product treated in the kiln, a first preheater coupled before the kiln and heated with kiln exit gases, and a second preheater heated with spent cooling air. According to the preferred embodiment, the method comprises the steps of feeding all of the raw material to the second preheater, conveying all of the raw material preheated in the second preheater to the first preheater, and returning to the cooler for reuse therein, all of the cooling air cooled in the second preheater. A unique plant is disclosed for practicing the method of the invention. The method and plant promote fuel economy and eliminate or at least minimizes dedusting requirements in the manufacture of such pulverous or granular material.

Abstract: Method and apparatus for heating aggregate in a system which includes a unit for mixing a stream of fuel and a stream of forced air to form a gaseous combustible fuel mixture, and a blower coupled to the unit for supplying it with forced air. The apparatus includes a water-spray device for injecting a fine-particle spray, at an adjustable water-volume rate, into the air-intake opening of the blower. In the method of the invention, the temperature of the heated aggregate is monitored under conditions where the fuel mixture is characterized by a substantially constant fuel-flow rate. The water-volume rate of atomized water spray introduced into the blower is adjusted until a maximum monitored aggregate temperature is observed. The amount of fuel in the moisture-containing fuel mixture is then adjusted to effect heating of the aggregate to a desired temperature.

Abstract: Coal is placed upon hot mineral solids being cooled by an upward flow of ambient air; the coal is dried, ignited and completely combusted under process conditions associated with cooling after firing. The hot off-gas from cooling is returned directly to the firing section or other sections of the process as heat.

Abstract: Method and apparatus for burning raw materials in the production of clinker from cement raw materials in which a portion of the cement raw materials are dried and partially deacidified under conditions which produce granules, while another portion of the raw materials in the form of finely divided meal is heat treated in a suspension type heat exchanger, and at least partly deacidified in a calciner forming part of the heat exchanger. The thus treated granules and meal are then mixed together and the mixture is treated in a thermal reactor such as a rotary kiln to complete deacidification and to cause the formation of the cement clinker.

Abstract: A method and apparatus for drying coal in which the coal is dried by a hot gas and then quickly cooled with ambient air to reduce the oxidation rate and in which the air heated in the cooler is supplied to support the combustion that generates the hot gas. The drying gas exhausted from the dryer is utilized to extract coal product, to produce the fuel necessary to generate the hot drying gas and to provide a tempering gas to help maintain the combustor within a desired temperature range. Condensation of the exhaust drying gas is prevented by utilizing the hot gas discharged from the combustor, bypassing the dryer, and supplying it to the exhaust gas at a plurality of different points.

Abstract: A method of firing granular carbonate minerals, for example a cement-calcine-forming meal, in which the comminuted solids are preheated in a fluidized bed or by like entrainment in a hot gas and then subjected to decarbonation in a precalcinator before entering a rotary kiln from which the cement clinker is discharged into a cooler for heat exchange between the hot clinker and air. According to the invention, the meal is suspended in the precalcinator, which forms an upright shaft at the inlet end of the kiln, so that the particles do not pass into the kiln directly from the precalcinator but rather can be entrained by the gases in the precalcinator, separated therefrom in a cyclone and delivered to the kiln. Fuel is mixed with the kiln exhaust gases just ahead of the zone at which the meal is suspended so that the sensible heat of the exhaust gas vaporizes the fuel or gasifies the latter.

Abstract: Air heated outside the calcining zone of a shaft kiln is passed through raw material in a hopper mounted above the kiln in order to preheat the raw material. In one embodiment the preheating air is heated by an excess air burner which communicates with the hopper. In another embodiment, the hot calcined material is cooled by forcing cool air through it and the heated air is utilized as preheating air by directing it through a by-pass conduit which connects the cooling zone of the kiln with an extension of the hopper. In neither embodiment does the preheating air constitute combustion supporting air.

Abstract: The invention relates to a method of burning, calcining or sintering fine-grain material in which the burnt material separated from the gas flow is supplied to a residence container from which a part of the material is returned to the burning zone and the remainder of the material is supplied to the cooling zone. Such a method is distinguished by a low heat and energy requirement and by a simple construction of the apparatus and permits ideal adaptation of the burning conditions to the particular material.

Abstract: A kiln system and method of operating the same, wherein a firing kiln is heated with pulverized fuel, and a crusher for the fuel and an air cooled cooling device for the fired material are provided, with at least a portion of the cooling air being supplied to the firing kiln as secondary air after passing through the cooling device, and the pulverized fuel being pneumatically taken from the crusher to a separator, from which the greatest portion of the pulverized fuel is supplied to the burner and from which the conveying air containing a small portion of the pulverized fuel is fed to the cooling device as cooling air.

Abstract: The rotary combustion bed has a rotary drum with a permeable refractory lining through which air is blown during rotation of the drum and cascading of a charge of material in the drum. The air may flow upwardly through the material at a predetermined fixed angle over an angle through which air is blown into the charge.

Abstract: Roller grate method and apparatus for simultaneously transporting, agitating and exchanging heat with a bed of solid mineral particles has elongated cylindrical horizontal rollers with gas passage apertures therethrough, a hopper for feeding mineral particles onto the rollers and forming a bed having a depth several times greater than the average diameter of the particles; a drive source to rotate the rollers and frictionally engage the cylindrical surfaces with the particles in the lowermost layer of the bed and urge the bed along a path of travel transverse to the axes of the rollers; elongated filler members disposed in the nip between adjacent rollers to prevent the particles from jamming the rollers and to provide resistance to the flow of the bed along said path of travel; and a heat chamber spanning the rollers and a fan for forcing a heat transfer gas stream through the gas passage apertures in the rollers and through the bed as it is being transported, the rollers and the filler members being adapted

Abstract: A fuel burning kiln and process especially adapted for utilizing solid fuel in which one or more burners are accommodated within the kiln and a fuel and air mixture and a supplementary air supply are supplied to the combustion chamber of the burner through a pair of conduits arranged in heat exchange relationship one inside the other.

Abstract: The present invention relates to a method for the heat treatment of finely divided materials, such as those used in the manufacture of cement. In the improved method of the present invention, two rows of suspension gas heat exchanges are provided, each row including a plurality of cyclone separators. A calcination furnace is connected to one of the rows, and a material cooler is connected to the other of the rows. In a preferred form of the invention, the row connected to the calcination furnace has at least one cyclone separator less than the row connected to the material cooler. A combustion device is also provided in conjunction with the material cooler to make more efficient use of the calcination furnace.

Abstract: A process for manufacturing calcium silicate and/or aluminate based products, such as Portland cement or aluminous cements. The raw material subjected to a first heating step in which it is heated in a preheater-decarbonator and/or a rotating kiln to a temperature less than that at which impurities, such as alkalines, chlorine and sulfur, are volatized. The heated raw material is then subjected to a second heating step in the presence of a reducing gas, preferably in a plasma furnace, the raw material being heated to a temperature higher than the temperature at which the impurities are volatilized, as for example above 1950.degree. C., and more than 80% of the material is in fusion, whereupon the material is cooled to produce the clinkers of improved quality and/or with lower energy consumption. An important feature of the invention is the utilization of the gases generated during the second heating step and during cooling to implement heating of the raw material.

Abstract: A process and system are disclosed for drying coal in a fluidized bed wherein the heat necessary for drying is provided by partial combustion of the coal in the bed. Proper control of the reaction parameters, particularly reaction temperature, provides an acceptably high drying rate along with an acceptably low production of pollutants in the off-gases. A particular embodiment of the invention provides for cooling of the dried coal by mixing such dried coal with an additional stream or additional streams of undried coal.

Abstract: A pre-heating assembly to be used for pre-heating ingots being transported to a melting furnace, which includes an inner cylinder constituting a main passage for exhaust gas discharged from a flue of the melting furnace, an outer cylinder which is positioned around the inner cylinder to leave a subsidiary passage for the exhaust gas between the two cylinders, an ingot supplying passage spirally provided along the outermost circumference of the inner cylinder, in which the ingots, each having a spherical configuration like a ball, roll down the passage in succession so that each ingot is pre-heated prior to its introduction into the melting furnace, and a connector support member, on which both cylinders are mounted and the bottom portion of the connector support member is coupled to the outlet of the flue.

Abstract: High temperature phosphate are burning process in which the ore is preheated by gases produced by the combustion of a fuel in the burning zone, and then enters the burning zone and is cooled by a current of cool air which is used, at least partly, as combustion in the burning zone, characterized by the fact that burning is carried out in a static combustion chamber in which the preheated ore is placed in suspension in the current of air which has cooled the burned ore and in which fuel is injected, whereby the combustion of air and fuel supplies the required heat for burning, and that the retention time of the ore in the combustion chamber is less than thirty seconds, the burned ore being blow out of the chamber by the gases resulting from the combustion of the fuel injected into the chamber.

Abstract: A process and an installation for the treatment of combustible granular or pulverulent material by drying and/or heating is disclosed. In one installation discharge gases are separated from dust in an electrostatic dust remover. Gases which have been partially recycled are divided between a direct recycling line and a path including the dust remover and a further duct so that the appropriate amount of gas is subject to dust removal to provide a desired throughput of gas. The dust captured by the dust remover is trapped in a hot liquid hydrocarbon and then used as a supplementary hydrocarbon binder.

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