Showing papers on "Rotary kiln published in 1979"

Rotary combustor wall

Abstract: A rotary kiln or combustor having a plurality of water cooled pipes secured together to define a cylinder in which material is burned. The cylinder slowly rotates about its axis, and the pipes are secured together so as to define a plurality of intermediate openings making the cylinder gas porous and through which combustion air is introduced. The improvement comprises providing a plurality of pins, secured directly to the pipes on the inside of the cylinder, that create a pattern of projections to support burning material slightly spaced from the inner cylinder wall.

Method of calcining sinterable materials to form cement clinker or the like

Abstract: Carbonate-containing sinterable material, e.g. for cement clinker, is calcined in a rotary kiln and then cooled in a grate cooler. The material is subjected to preheating in a suspension preheater and then to precalcination in an upright precalcining installation. The fuel for the latter is introduced through nozzles into a substantially oxygen-free crude power exhaust gas suspension and after turbulent mixing of the fuel with this suspension a stoichiometric quantity of combustion air is introduced so that a flameless combustion occurs in the turbulent mixture. Thereafter the solids enter the rotary kiln for the final calcination.

Method for effectively utilizing waste tires

Abstract: Waste tires are used in production of cement using a rotary kiln for saving the use of fuel by feeding waste tires as such or crushed waste tire pieces to the position where the temperature of the exhaust gas in this apparatus is 600°-1,400° C. in an amount of not more than 60% of the total used fuel calculated as heat energy.

Inert grinding and direct firing in coal burning systems

Abstract: A system in which coal is ground and transported in an inert atmosphere to a place of burning which may be a rotary kiln or a furnace, and in which system the coal being ground is used as the medium to produce the drying and inerting while the transporting media is the air brought in from outside the system and treated in a heating unit to consume part of the normal oxygen so it is rendered inert by the time it circulates in the system as the transporting media.

Method of converting a rotary kiln cement making plant to a calcining furnace cement making plant

Abstract: A method for converting existing long rotary kiln wet or dry process cement making plants to a more energy efficient operation including removing a central section of an existing rotary kiln and replacing it with a furnace and associated material separator for calcining material received from a first beginning section of the existing kiln which functions as a preheater and for supplying the calcined material to an end portion of the existing kiln which serves as a clinkering device

Pyrolysis process for scrap tires

Abstract: A process for disposal of scrap tires was developed in which the shredded tires are pyrolyzed in an indirectly heated rotary kiln at 600/sup 0/C to produce mainly fuel oil and char. The operating temperature was determined as the temperature which produces the char that gives carbon black with optimum properties as reinforcing filler for rubber. The oil is condensed in two stages. The gas is used with light oil to heat the kilns. Cost estimates for 4000-14,000 ton/yr plants, balanced against credit for recovered materials and the cost of collecting and transporting scrap tires show an optimum plant size of 7000 tons/yr. A demonstration plant of that size is under construction.

Burner for a kiln

Abstract: A burner for pulverized coal such as in a rotary kiln includes three concentric cylindrical ducts. The outer duct carries an air supply which is directed in a generally axial direction into the kiln. The next innermost duct carries the pulverized coal-carrier gas mixture and is also generally directed in an axial direction. The next innermost duct carries air which is directed in a divergent radial direction in the kiln and includes a rotational air component. By controlling the quantities of air in the ducts which flank the coal duct, the resulting flame form can be controlled in the kiln without restoring to variations in the velocity or direction of the coal carrier gas stream. By eliminating such variations in regard to the coal carrier gas stream, the abrasive action of the pulverized coal is kept to a minimum.

System for the protection of the delivery end of a rotary kiln

Abstract: This invention concerns a system for the protection of the delivery end of a rotary kiln. This system is characterized by the fact that it consists of a refractory concrete ring covering the internal surface of the end of the kiln shell and the front surface of a flange attached to the outside of the end of the shell, the ring being fastened to the shell and the flange by anchorage units fixed on them. The invention can be used in the cement production and minerals processing industries.

Combustion control system for burning installation with calcining burner

Abstract: A combustion control system for a rotary kiln with a suspension preheater including a calcining burner wherein slurries of Portland cement raw materials, lime slurries, alumina, magnesia or the like are filtered into a cake, the cake being burned in the kiln with the suspension preheater

Preparation of light calcium carbonate

Abstract: PURPOSE:To obtain high calcium carbonate which has a quality similar to a commercially available high pure product and which is particularly useful as an accelerator for desulfurizatin agent of hot iron, by introducing granulated carbide slag in a rotary kiln and blowing CO and O2 into it to carry out carbonation within a specified temp. range. CONSTITUTION:A granulating assistant such as PVA etc, or water is added to carbide slag in an amount of 0.1-10wt% to granulate it at a size of 5-50mm.. Granules are then introduced from one end of a rotary kiln, and CO and O2 are blown from the other end to burn CO and maintain them at the temp. of 500-900 deg.C in CO2 atmosphere. Thereby, Ca(OH)2 which is a main component of carbide slag is carbonated. Light calcium carbide obtd. by this carbonation is anhydrous and a light product with an average granular size <1mu.

Apparatus and method for compacting, degassing and carbonizing carbonaceous agglomerates

Abstract: An apparatus for compacting, degassing and carbonizing carbonaceous agglomerates, the apparatus comprising a rotary kiln having an agglomerate inlet means for introducing green agglomerates into the kiln near the inlet of the kiln and a heating medium inlet for introducing a heating medium comprising a finely divided solid into the kiln at a preselected location intermediate the inlet end of the kiln and the outlet end of the kiln to produce a mixture at a temperature above the carbonizing temperature of the agglomerates and a sieve positioned to receive the products from the rotary kiln and separate the heating medium and the compacted, degassed, carbonized agglomerate product. A method for producing compacted, degassed, carbonized carbonaceous agglomerates by the use of the apparatus is also disclosed.

Waelz process of volatilizing zinc and lead from iron oxide-containing materials

Abstract: In a Waelz process of volatilizing zinc and lead from iron-containing and oxide-containing material in an inclined rotary kiln, which is charged at its upper end with the material together with solid carbonaceous reducing agent having a high content of volatile combustible constituents, wherein the reduction and volatilization are effected below the softening point of the charge, metallic iron-containing material is discharged from the lower end of the rotary kiln, combustion air is sucked into the lower end of the rotary kiln, and the exhaust gases are sucked from the upper end, the improvement which comprises blowing oxygen-containing gases through tubular air nozzles into the charge disposed over said tubular air nozzles in that region of the heating-up zone which begins where ignitable particles of the solid reducing agent begin to occur and which terminates at up to 50 percent of the length of the kiln.

Method and system for burning fine-grained material, particularly for the manufacture of cement clinkers

Abstract: The invention relates to a method for burning fine-grain material, particularly for the manufacture of cement clinker from cement raw meal. The material is thermally treated in a multistage burning process with a pre-heating stage, a calcining stage with a high-degree of calcination, a sintering stage in a very short rotary kiln and a cooling stage. Fuel is introduced both into the sintering stage in the short rotary kiln as well as into the calcinating stage. Hot exhaust air from the cooling stage is supplied both to the sintering stage as well as to the calcining stage as furnace air. The invention also relates to an apparatus for the manufacture of mineral products of the burning process such as cement clinker.

Direct drive system for rotary kiln or mill - includes guide bearings between stator and rotor of driving motor

Abstract: The rotor (4) of the driving motor is mounted directly on the tube (1) forming the kiln. and preferably close to a bearing (2). In order to compensate for tube eccentricities the motor stator (5) is mounted directly on the rotor the parts being separated by a ball or roller bearing system. A torque arm (7) with universal joints (6, 8) supports the reaction on the stator. The construction allows the machine to follow irregularities in the kiln tube movement without affecting the motor air gap. This gap can now be made quite small and thus allows the use of an induction motor as the drive or the kiln.

Hydration of lime

Abstract: An already existing conventional lime production plant using a rotary kiln discharging directly into a rotary cooler, is converted reversibly to the production of dry hydrated lime by introducing water into contact with the lime in the cooler sufficient to hydrate the lime without requiring any significant change in the operating parameters of the lime production such as material throughput, cooling and combustion air supply rates and firing conditions.

Process for producing metallized pellets from raw pellets by controlling distribution of temperature in a rotary kiln

Abstract: A process for reducing pellets containing metal oxides, such as chrome oxide, iron oxide, zinc oxide, etc. with the contained carbon to metallized pellets in a rotary kiln, characterized by carrying out the reduction while blowing air or spraying water into the portion near the charge end of the kiln in order to prevent too rapid heating of the raw pellets is disclosed.

Method of utilizing fly ash from power works and refuse disposal plants in the production of cement clinkers, and a plant for carrying out said method

Abstract: A process for producing cement clinkers is disclosed whereby fly ash is added to the lower as well as to the upper end of a rotary kiln containing a firing zone and wherein the fly ash is admixed with calcareous materials in accordance with the desired composition of the product.

Drehrohrreaktoren in der Chemietechnik

Abstract: Rotary kiln in chemical engineering. This review stresses the importance of rotary kilns in industry. After a brief account of design considerations, the following processes are treated: particle and product motion, longitudinal and transverse transfer of solids, mass- and heat transfer, as well as chemical reactions. Common models used for rotary kilns are discussed. Typical industrial processes employing rotary kilns are presented. The present status of control and automation of these plants are discussed.

Method of recovering valuable metal or the like from steel-making electric furnace dust

Abstract: PURPOSE: To efficiently recover a valuable metal and a harmful metal, by using a mixture of coke and coal as a reducing agent for reduction of duct, effecting high- temperature reduction and continuously measuring the temperature of an atmosphere to control the distribution of the temperature to be appropriate. CONSTITUTION: Dust collected from an electric furnace is made into pellets. The pellets are charged into a rotary kiln 1 together with a reducing agent which is prepared by mixing 100pts.wt. of coke with 20W100pts.wt. of coal. The pellets are moved in the kiln 1 so that the pellets are reduced at 1,200W1,400°C in the sequence of iron, zinc, lead, etc. At that time, early reduced iron is oxidized again in a high- temperature region. The reduction of the zinc, lead, etc. is accelerated by the heat of the oxidation. Evaporated zinc lead, etc. change into oxides, which go out of a furnace end hood 3 and are collected by a cyclone 8 and a dust collector 9. Exhaust gas is released through a chimney 11. Thermometers T 1 WT 5 are installed in the kiln 1 to continuously measure the temperature of the atmosphere. The pressure in the furnace, the oil combustion in a burner 5, the mixture ratio and addition ratio of the reducing agent, etc. are controlled depending on the difference between the measured temperature and a standard value to keep the temperature of the atmosphere in the kiln appropriate. COPYRIGHT: (C)1981,JPO&Japio

Incinerating kiln that its center portion is expanded

Abstract: PURPOSE:To prevent the dispersion of incinerated combustible matters, by prolonging the retention time of matters to be burnt by expanding the diameter of a center portion of a rotary kiln to perfectly burn the matters while reducing the speed of combustion gas, in the rotary kiln that burns waste matters. CONSTITUTION:In a rotary kiln, etc. that burn waste matters, a kiln body 1 is integrally arranged by a central expanded portion 1a and conical inlet cylinder 2 and outlet cylinder 3 connected to the portion 1a, and the body 1 is supported by a roller 12 through a tire 13 and turned by means of a drive device 11. In this case, a port 4 for supplying matters to be burnt, a duct 6 for feeding air for combustion and an auxiliary combustion burner 7 are mounted to the inlet cylinder 2 side, and a feed pipe 9, which can be taken out and put into the body 1, and an ash hopper 5 are installed to the outlet cylinder 3 side. Thus, the desirable target can effectively be attained because the volume of the kiln can be expanded.

Trap-port for rotary kilns

Abstract: A labyrinth port structure minimizes entrapment of fine particulates in the port piping of a rotary kiln and maintains a self-flushing operation which permits turbulent mixing resulting in particulate removal from port cavities.

Rotary drum and method of mixing, drying, cooling, heating or calcining solid particles

Abstract: A mixer block (20) for use in a rotary kiln (10) for mixing, drying, cooling, heating, or calcining of solid materials such as gravel, stone or fluxes, has a base surface (21), two aide surfaces (22, 23) converging away from the base surface (21) to define therewith a generally triangular cross-sectional shape. In use in the rotating kiln one (22) of the converging side surfaces serves as a leading surface and the other (23) as a trailing surface. The base surface (21) and the two converging side surfaces intersect to include respective angles which are between plus 10* and minus 10* of the angle of repose of the material being troated, the block (20) thereby producing a more uniform product with minimal production of fines and dust. The mixer block (20) is especially useful when used as part of the refractory lining (12) in a rotary kiln to calcine fluxstone such as limestone, dolomite, dolomitic limestone or magnes i te.

Air supply device for rotary kiln type incinerator

Abstract: PURPOSE: To positively supply auxiliary combustion air and efficiently burn refuse by providing a nozzle port capable of supplying auxiliary combustion air toward the refuse in a furnace in a blowing tube connected to the blowing unit side out of an outlet hood at the ash storage side of a rotary furnace body. CONSTITUTION: A cylindrical column 1 arragned at suitable gradient between the inlet hood 5 and an outlet hood 8 of a rotary kiln type incinerator is rotated at lower speed by a motor 3 to burn the refuse W thrown from the inlet 6 of the inlet hood 5 by the flame F from a burner 7 and to accumulate ash W' in an ash storage chamber 10. In this case, a movable rotary supporting mechanism 12 and a blowing tube 24 having a number of nozzle ports and supported by the mechanism 12 is provided as an suxiliary combustion air supply device. The auxiliary combustion air is injected into the furnace by a blower 11 while rotating the tube 24 to efficiently burn the refuse in the furnace. COPYRIGHT: (C)1980,JPO&Japio

Apparatus for compacting, degassing and carbonizing carbonaceous agglomerates

Abstract: An apparatus for compacting, degassing and carbonizing carbonaceous agglomerates, the apparatus comprising a rotary kiln having an agglomerate inlet means for introducing green agglomerates into the kiln near the inlet of the kiln and a heating medium inlet for introducing a heating medium comprising a finely divided solid into the kiln at a preselected location intermediate the inlet end of the kiln and the outlet end of the kiln to produce a mixture at a temperature above the carbonizing temperature of the agglomerates and a sieve positioned to receive the products from the rotary kiln and separate the heating medium and the compacted, degassed, carbonized agglomerate product. A method for producing compacted, degassed, carbonized carbonaceous agglomerates by the use of the apparatus is also disclosed.

Melting and reducing method for iron oxide

Abstract: PURPOSE:To economically manufactre hot iron without using a blast furnace by melting and reduxing reduced iron pellets, in a melt-reduction furnace using a burner flame as the main heat source, in which more than 12% of Fe contained is left in the form of its oxide. CONSTITUTION:Iron oxide pellets 4 made of lumpy iron ore, fine iron ore dust, etc. are charged into rotary kiln 3 and brought into countercurrent contact with a hot reducing gas from melt-reducing furnace 5 connected to the end of kiln 3. Thus, pellets 4 are subjected to solid phase reduciton with the gas and fed to furnace 5 while leaving more than 12% of Fe contained in the form of its oxide. In furnace 5, fuel such as heavy oil, natural gas or dust coal is burned by burner 9 with pure oxygen. At the same time, a reducing agent such as coke is added and the amt. of oxygen supplied from burner 9 is controlled, thereby economically manufacturing hot iron without over-reduction.

Method and apparatus for sealing rotary furnace bodies

Abstract: PURPOSE:To seal between furnace body and hoods by forming a magnetic field in the joint parts between the furnace body of a rotary kiln and the fixing hoods at its both ends and holding magnetic material such as iron power or the like. CONSTITUTION:An annular body 8 made of non-magnetic material such as austenite base stainless steel or the like is mounted on the surface of the fixing hoods 3, 3 provided at both ends of the furnace body 1 of a rotary kiln, opposing to the furnace body 1. Magnetic alloy 9 is mounted without any spacing on the outside circumferential surface of the annular body 8. A rib 10 composed of magnetic material is provided over the entire circumference of the outside circumferential surface of the furnace body 1 corresponding to the magnet 9. If iron power F is filled in the spacing between the rib 10 and annular body 9 at the time of rotating the furnace body 1 of the rotary kiln 1, it may be deposited and held in the above spacing by magnetic force through the action of the magnetic field. In this case, the iron power of 16 mesh or under is used and the intensity of the magnetic field is set at 1000 gauss, whereby between the furnace body 1 and the hood 3 may be perfectly sealed.

Apparatus for cooling of cement clinker or the like

Abstract: Apparatus for the cooling of cement clinker or the like being discharged from a rotary kiln, the apparatus including at least two cooling means arranged to receive the discharge from the rotary kiln and adjustably positionable distributor means arranged to proportion the discharge of the rotary kiln selectively between the two or more cooling means.

Cyclone type rotary kiln

Abstract: PURPOSE:To provide a cyclone type rotary kiln so constructed that the air current having flown in through an air supply port turns toward the end of the conical portion thereof and is discharged through the central portion of this turning current and capable of reducing dusting. CONSTITUTION:A kiln body 1 is turned in arrow direction (a) by the not-illustrated driving system connected to a support device 7, and the disposal material 8 supplied through a supply port 4 is agitated. In the meanwhile, the air supplied through an air supply port 6 comes in contact with said disposal material 8 and flows in the same manner as a cyclone dust collector, i.e. flows toward the tapered end portion 1A of said kiln body 1 while turning as indicated by arrow (b), returns, and is discharged through a discharge port 5 after passing though the central portion of turning current. In the meanwhile, said disposal material gradually becomes ash 8A. Said ash 8A reaches a dust box 2 through said end portion 1A after repeating vertical movement as indicated by arrows (c) and (d). Thereby, a decreased amount of ash or the like is carried away by air current.

Protection device for the discharge end of a rotary-drum furnace

Abstract: not available for EP0012660Abstract of corresponding document: US4295825This invention concerns a system for the protection of the delivery end of a rotary kiln. This system is characterized by the fact that it consists of a refractory concrete ring covering the internal surface of the end of the kiln shell and the front surface of a flange attached to the outside of the end of the shell, the ring being fastened to the shell and the flange by anchorage units fixed on them. The invention can be used in the cement production and minerals processing industries.

Direct reduction process in a rotary kiln

Abstract: An improved process for the direct reduction of iron oxide-containing materials to form sponge iron which takes place in a rotary kiln by treatment with a solid carbonaceous reducing agent having a high content of volatile combustible constituents is disclosed. The charge is moved through the rotary kiln opposite to the direction of flow of the kiln atmosphere. Oxygen-containing gases are blown at controlled rates through nozzle blocks into the charge disposed over the nozzle blocks in the heating-up zone in that region thereof defined by the occurrence of ignitable particles of the solid reducing agent and ending before the reduction zone. Oxygen-containing gases are blown in at controlled rates through shell tubes into the free kiln space at least in that region. In accordance with the invention, at least a part of the solid carbonaceous reducing agent comprises disintegrated waste rubber. Preferably more than 80% of the solid carbonaceous reducing agent comprises waste rubber.