Showing papers on "Rotary kiln published in 2005"
TL;DR: In this paper, an energy audit analysis of a dry type rotary kiln system working in a cement plant in Turkey was conducted and it was found that about 40% of the total input energy was being lost through hot flue gas (19.15%), cooler stack (5.61%), and kiln shell (15.11% convection plus radiation).
217 citations
TL;DR: In this article, an extended penetration theory is successfully developed to describe the heat transfer coefficient of the covered wall to the bulk solid in a rotary kiln, i.e., h cw-cb = (Xd p /k g + 0.5/2k b ρ b c pb n/Φ 0 ) -1 (0.096 < x < 0.198).
Abstract: Rotary kilns are used ubiquitously in the chemical and metallurgical industries. The mechanism of heat transfer in a rotary kiln is discussed in this paper, in which the effect of rotation is considered in determining heat transfer coefficients. In particular, an extended penetration theory is successfully developed to describe the heat transfer coefficient of the covered wall to the bulk solid in a rotary kiln, i.e., h cw-cb = (Xd p /k g + 0.5/2k b ρ b c pb n/Φ 0 ) -1 (0.096 < x < 0.198). A one-dimensional axial heat transfer model for an internally heated rotary kiln has been developed. Both predicted temperature profiles and heat transfer fluxes agree well with the experimental data of Barr et al. The simulated results are used to successfully explain for the first time the coupling phenomenon of the bulk bed and covered wall temperatures discussed in previous publications.
85 citations
TL;DR: In this article, a scaleable solar multitube rotary kiln was designed and tested to effect the endothermic calcination reaction CaCO 3 →CaO+CO 2 at above 1300 K.
Abstract: We designed and tested a scaleable solar multitube rotary kiln to effect the endothermic calcination reaction CaCO 3 →CaO+CO 2 at above 1300 K. The indirect heating 10-kW reactor prototype processes 1-5 mm limestone particles, producing high purity lime of any desired reactivity and with a degree of calcination exceeding 98%. The reactor's efficiency, defined as the enthalpy of the calcination reaction at ambient temperature (3184 kJ kg -1 ) divided by the solar energy input, reached 30%-35% for solar flux inputs of about 2000 kW m -2 and for quicklime production rates up to 4 kg h -1 . The use of concentrated solar energy in place of fossil fuels as the source of process heat has the potential of reducing by 20% CO 2 emissions in a state-of-the-art lime plant and by 40% in a conventional cement plant.
68 citations
TL;DR: In this article, the mathematical modelling of a rotary kiln, which is used for the recycling of aluminium waste, is described and the software Fluent ™ is used in order to solve this model.
39 citations
TL;DR: In this article, a dynamical model computing the evolution of the flow rate of granular solids through the kiln has been developed based on the Saeman model, which gives good results for the rolling mode, but for the slipping mode too.
Abstract: Experiments for the investigation of the flow of granular solids in a pyrolysis pilot-scale rotary kiln are presented. These experiments consisted first in measuring the volumetric filling ratio (steady-state experiences) for several operating conditions and second in recording the exit flow rates after a positive or negative step in one of the operating parameters (dynamic experiences). A dynamical model computing the evolution of the flow rate of granular solids through the kiln has been developed based on Saeman model [Chem. Eng. Prog. 47 (1951) 508]. The simulations are compared with experimental results; the model gives good results for the rolling mode, but for the slipping mode too.
36 citations
TL;DR: In this article, the authors present the development of oxygenated roasting for refractory gold ores and concentrates, and describe the advantages and disadvantages of each process, including Rotary kiln, multiple hearths, fluidized bed, and CFB.
Abstract: Publisher Summary For the recovery of gold from refractory ores and concentrates, roasting has been used extensively for decades. For severe refractory gold ores, it was the exclusive pre-treatment process and accordingly, its development is presented in detail, finishing with the most recent technology; oxygenated roasting for whole ores. Commercially, four important steps have been witnessed in the development of roaster equipment: Rotary kiln and multiple hearths (e.g. Edwards), fluidized bed (e.g. DORR-Oliver), circulating fluidized bed (CFB) (e.g. Inco and Lurgi), and oxygenated fluidized bed (e.g. Independence and Goldstrike). The chapter describes the advantages and disadvantages of each process. The development of new technologies is driven by increased throughput requirements, improving efficiencies, reducing costs, and increasing environmental concerns.
33 citations
TL;DR: A dynamic simulation system (DSS) and a simulation study of a pilot scale rotary kiln for activated carbon manufacture, where the good performance exhibited by the DSS makes it suitable for controller's design and synthesis purposes.
29 citations
Patent•
19 Jan 2005
TL;DR: In this article, a bypass system for a cement clinker production line is proposed, which is characterized by particularly low investment costs and operating costs, thus being economically favorable. But this bypass system is not suitable for large-scale production lines.
Abstract: The aim of the invention is to create a bypass system for a cement clinker production line, which is characterized by particularly low investment costs and operating costs, thus being economically favorable. Said aim is achieved by installing the bypass system in such a way that the capacity of pre-existing system filters such as the main exhaust gas filter and/or the cooler exhaust filter can also be used for treating the bypass gas flow.
23 citations
TL;DR: In this article, a rotary kiln and a fluidized bed was used to synthesize nanocrystalline Ta3N5 and Zr2ON2 films, and the reaction time was reduced by optimizing the ammonia flow, the temperature and reaction time.
Abstract: Thin (d = 60 nm/140 nm) nanocrystalline Ta3N5 and Zr2ON2 films were synthesized in a rotary kiln and in a fluidized bed apparatus. The control of the reaction was performed by optimizing the ammonia flow, the temperature and the reaction time. Using fluidized bed technology, the reaction times were significantly reduced compared to a stationary oven and to a rotary kiln. Movement of the particles in the gas phase favors gas–solid interaction that enhances gas diffusion in the pores. In addition, complete reactions and homogeneous products were obtained in the fluidized bed and not in a rotary kiln, which resulted in pigments having a stronger interference color.
20 citations
Patent•
23 Feb 2005
TL;DR: In this article, a process for innocuously treating the used liner of aluminium electrolyzer includes such steps as proportionaly mixing it with the calcium oxide contained ore, SiO2 contained material and bitumite, heat treating in rotary kiln, adsorbing tail gas by alumina, and leaching the treated material by lime milk for secondary reaction.
Abstract: A process for innocuously treating the used liner of aluminium electrolyzer includes such steps as proportionaly mixing it with the calcium oxide contained ore, SiO2 contained material and bitumite, heat treating in rotary kiln, adsorbing tail gas by alumina, and leaching the treated material by lime milk for secondary reaction. It can greatly decrease the contents of fluoride and cyanide in the treated dregs, which can be used to prepare cement or refractory or for building road.
17 citations
Patent•
19 Jan 2005
TL;DR: In this paper, an infrared scanning method for rotary kiln barrel temperature monitoring is proposed, where the surface temperature of the barrel is measured by infrared radiation temperature measuring, and then the temperature and relevant position signals are converted into axial temperature distribution graph, two dimensional expansion chart, circumferential temperature graph and three-dimensional heat image.
Abstract: This invention discloses an infrared scanning monitoring method for rotary kiln barrel temperature It is to monitor the surface temperature of barrel by principle of infrared radiation temperature measuring, and to turn the surface temperature and relevant position signals into axial temperature distribution graph, two dimensional expansion chart, circumferential temperature graph and three-dimensional heat image This invention can realize the real time monitoring of rotary kiln barrel temperature and greatly reduce labor intensity and work accidents and improve the operation ratio and production and quality of the rotary kiln and can lower cost and non-scheduled ceasing time of kiln
Patent•
02 Mar 2005
TL;DR: In this article, a reflux type temperature controllable sludge drying apparatus and method is presented. But, the method is not suitable for large sized sludge, as it can lose over 95 % of its organic matter components.
Abstract: The present invention discloses one kind reflux type temperature controllable sludge drying apparatus and method. Drying sludge in 5-20 % is mixed with wet sludge and through the sludge inlet with two, one transverse and one longitudinal, layers of cutting steel wires, sludge is cut into small blocks before entering into the rotary kiln. Inside the rotary kiln, sludge is thrown and crushed by the throwing plate and chain for fast heating to dry in the temperature controlled with the jetting blower. Hot sludge from the rotary kiln is blown with the cold wind blower to further dry. The dried sludge is crushed and sieved, sludge with size below 4 mm is pelletized for comprehensive utilization and large sized sludge is refluxed. The present invention can reach ideal drying effect while maintaining over 95 % of its organic matter components.
Patent•
27 Jul 2005
TL;DR: A combined production of aluminum and cement from fly-ash and limestone is carried out by roasting by drying method rotary kiln with aluminum oxide clinker as clinker without alkali powder, coarse liquid aluminum oxide carbon separating, dissolving out by low-temperature Bayer process, and obtaining first-level sanding aluminum oxide as mentioned in this paper.
Abstract: A combined production of aluminum and cement from fly-ash and limestone is carried out by roasting by drying method rotary kiln with aluminum oxide clinker as clinker without alkali powder, coarse liquid aluminum oxide carbon separating, dissolving out by low-temperature Bayer process, and obtaining first-level sanding aluminum oxide. The produced tail gas carbon dioxide from cement kiln is used for coarse liquid carbon separating procedure, and strengthens thickness of carbon dioxide and calcium silicon slag. It has no pollution and saves energy resource.
15 May 2005
TL;DR: In this paper, the potential impact of using post-consumer carpet as an alternative fuel in cement kilns was evaluated using a rotary kiln simulator with polypropylene, nylon 6 and nylon 6,6 face fiber.
Abstract: Transient puff emissions were characterized from burning carpet charges that were fed to a pilot-scale rotary kiln combustor to assess the potential impact on emissions of using post-consumer carpet as an alternative fuel in cement kilns. Carpet with polypropylene, nylon 6, and nylon 6,6 face fiber was cut in one to three inch square pieces and fed as 0.4 kg charges to a 73 kW natural gas fired rotary kiln simulator. Gas emissions monitored included O/sub 2/, CO/sub 2/, CO, NO, NO/sub X/, N/sub 2/O, NH/sub 3/, total hydrocarbons, and total polycyclic aromatic hydrocarbons. The charges required about two minutes to burn, and the emission transient exhibited three phases. In the first phase lasting about 30 seconds, fuel-lean combustion of volatiles occurred. In the middle phase lasting about one minute, fuel-rich burning occurred and a CO spike was observed. In the final phase lasting about 30 seconds, fuel-lean burning occurred. For nylon carpets, the fuel-lean combustion periods were characterized by elevated NO emissions. Integrated over the duration of the transient, the NO emission corresponded to a one to two percent conversion of fuel-nitrogen (i.e. nitrogen in the nylon fiber) to NO. These tests demonstrate the feasibility of burning waste carpet as an alternative fuel, that rapid volatilization of batch fed carpet can lead to emission transients, and that NO emissions may result from the burning of nylon carpets.
Patent•
20 Apr 2005
TL;DR: In this paper, the authors proposed a utility model for rotary kiln, which consists of a kiln body position coder, a Kiln cylinder synchronization signal generator, a circumferential coordinate system, a temperature measuring box, a communications adapter and an industrial computer.
Abstract: The utility model provides an infrared temperature scanning and monitoring system, in particular to an infrared temperature scanning and monitoring system for rotary kiln. The utility model comprises a kiln body position coder, a kiln cylinder synchronization signal generator, a circumferential coordinate system, a temperature measuring box, a communications adapter and an industrial computer. The utility model can reduce labor intensity and industrial accident, improves running rate, production and quality of kiln, and reduces production cost and unscheduled shutting down time of kiln.
Patent•
19 Apr 2005
TL;DR: In this article, a method for producing quicklime/soft-burned dolomite, in which a gas fuel and waste plastics are burned as a main fuel and a sub-fuel, respectively, in a rotary kiln and by which the generation of coating in the rotating kiln can be suppressed.
Abstract: PROBLEM TO BE SOLVED: To provide a method for producing quicklime/soft-burned dolomite, in which a gas fuel and waste plastics are burned as a main fuel and a sub-fuel, respectively, in a rotary kiln and by which the generation of coating in the rotary kiln can be suppressed. SOLUTION: In the method for producing the quicklime/lightly calcined dolomite, a raw material is fired by burning the waste plastics being the sub-fuel together with the gas fuel being the main fuel in the rotary kiln. The waste plastics are charged through a main fuel burner 20 in which a waste plastic blowing-out port 21, a gas fuel blowing-out port 22, a blowing-out port 23 for an inner flow of primary air, and a blowing-out port 24 for an outer flow of primary air are each formed in the order of from the inside to the outside, and a main fuel burner 20 has a rotating blade is formed at the blowing-out port 23 for the inner flow of the primary air, and waste plastics is charged and burned via the main burner. COPYRIGHT: (C)2007,JPO&INPIT
Patent•
19 Jan 2005
TL;DR: In this paper, a rotary kiln refuse gasification method was proposed to eliminate fly ash source which acts as a catalyst in dioxin and heavy metal formation reaction, and also increases efficiency of carbon conversion of system combustion without increasing energy consumption basically.
Abstract: A charcoal-ash interfusion multistage burning method and system for rotary kiln refuse gasification relates to environmental protection technical field. The method comprises: loading the broken and compacted refuse in a kiln-gas gasifier; implementing partial heat release gasification after the refuse counter current contacting heating with high temperature fume; generating waste gas with lower calorific value entering a high temperature melt type combustion furnace; separating metal monomer by sorting unit after elimination of solid bottoms in the kiln-gas gasifier; grinding other charcoal components, pneumatically conveying them in the high temperature melt type combustion furnace, and making them melting and burning with gas; discharging water quenched slag; and chilling discharged fume after heat recovery by a waste heat boiler, and discharging it into the air via dry purification. The invention not only fundamentally eliminates fly ash source which acts as a catalyst in dioxin and heavy metal formation reaction, but also increases efficiency of carbon conversion of system combustion without increasing energy consumption basically. At the same time, the invention also implements metal resource monomer recovery.
TL;DR: In this paper, a numerical simulation of the physico-chemical processes occurring inside a heated rotary kiln reactor, where coal, lignite or biomass are treated in vacuum for the production of clean solid fuel, has been performed with FLUENT6 Computational Fluid Dynamics (CFD) code.
Patent•
23 Feb 2005
TL;DR: In this paper, a method and device relate to elimination of attachments in a rotary kiln is presented, which consists of a set of rails, a pulley on them, an arm with a scraper on its front end, which is installed on the pulley to extend into the kiln, and cooling medium channels installed in the arm and scraper.
Abstract: A method and device relate to elimination of attachments in a rotary kiln. The device consists of a set of rails, a pulley on them, an arm with a scraper on its front end, which is installed on the pulley to extend into the kiln, and cooling medium channels installed in the arm and scraper. Attachments are automatically removed when the rotary kiln rotates and shifts oppositely.
Patent•
09 Nov 2005
TL;DR: In this article, a composite mullite brick for alkaline rotary kiln is proportionally prepared from the sewage of sulfite paper pulp, special grade high-Al alumine as aggregate, superfine alumine powder, fine class-3 alumine, alpha-Al2O3 powder, ZrO2 powder and white clay.
Abstract: A composite mullite brick for alkaline rotary kiln is proportionally prepared from the sewage of sulfite paper pulp, special-grade high-Al alumine as aggregate, superfine alumine powder, fine class-3 alumine powder, alpha-Al2O3 powder, ZrO2 powder and white clay. Its advantages are high resistance to high temp (1400-1530 deg.C), alkali and heat shock, and high strength.
Patent•
10 Jun 2005
TL;DR: In this article, a rotary kiln is used for manufacturing cement clinker, where hot particulate material from the kiln was sent to an inlet grate in the cooler, and the channels for cooling air were blanked off in connection with the injection of compressed air.
Abstract: Described is method as well as a cooler (1) for cooling hot particulate material which has been the subject of heat treatment in an industrial furnace, such as a rotary kiln (3) for manufacturing cement clinker, by which method the hot material from the kiln (3) is directed to an inlet grate (21) in the cooler (1), in which cooling air from an underlying compartment (24) is led via a number of channels (28) through gaps (20) in the inlet grate for cooling the hot material and where compressed air from a separate system (25) via a number of ducts (26) can be intermittently injected into the material on the inlet grate (21). The channels (28) for cooling air are blanked off in connection with the injection of compressed air.
Patent•
12 Jan 2005
TL;DR: In this article, coal, silica and bauxite are processed by drying, grinding, prilling and drying, then to be sent into rotary kiln to be roasted, reacted furnace gas is processed by dedusting, hydration absorbing and purifying to produce phosphate product, roasted reacted furnace dregs can be used to produce cement by adding calcined gypsum and shell the being grinded to powder.
Abstract: Phosphate ore, coal, silica and bauxite are processed by drying, grinding, prilling and drying, then to be send into rotary kiln to be roasted, reacted furnace gas is processed by dedusting, hydration absorbing and purifying to produce phosphate product, roasted reacted furnace dregs can be used to produce cement by adding calcined gypsum and shell the being grinded to powder.
Patent•
03 Jun 2005
TL;DR: A direct heat kiln process for the production of phosphoric acid from phosphate ore utilizing a reductant process in combination with a carbon source, silica and heat is described in this paper.
Abstract: A direct heat kiln process for the production of phosphoric acid from phosphate ore utilizing a reductant process in combination with a carbon source, silica and heat. The process employs air control to control the burning rate of the product gasses from the kiln bed in order to control the overhead temperature in the kiln and the kiln bed temperature. In order to keep the reaction temperature at the lower ranges to prevent melting. The kiln feed ball constituents are co-ground and finely ground to lower the required bed temperature to minimize melting.
01 Jan 2005-Journal of Environmental Science and Health Part A-toxic\/hazardous Substances & Environmental Engineering
TL;DR: Through CFD simulation, a better process understanding and potential optimization of the design were attained, and the distribution of temperature and chemical species has been investigated.
Abstract: Hazardous wastes have complex physical forms and chemical compositions and are normally incinerated in rotary kilns for safe disposal and energy recovery. In the rotary kiln, the multifeed stream and wide variation of thermal, physical, and chemical properties of the wastes cause the incineration system to be highly heterogeneous, with severe temperature fluctuations and unsteady combustion chemistry. Incomplete combustion is often the consequence, and the process is difficult to control. In this article, modeling of the waste combustion is described by using computational fluid dynamics (CFD). Through CFD simulation, gas flow and mixing, turbulent combustion, and heat transfer inside the incinerator were predicted and visualized. As the first step, the waste in various forms was modeled to a hydrocarbon-based virtual fuel mixture. The combustion of the simplified waste was then simulated with a seven-gas combustion model within a CFD framework. Comparison was made with previous global three-gas combustion model with which no chemical behavior can be derived. The distribution of temperature and chemical species has been investigated. The waste combustion model was validated with temperature measurements. Various operating conditions and the influence on the incineration performance were then simulated. Through this research, a better process understanding and potential optimization of the design were attained.
Patent•
30 Jun 2005
TL;DR: In this article, the main element of the annealing separating agent for a large-sized electric steel sheet coil was used for a grain-oriented electric steel coil with excellent coating characteristic and excellent magnetic properties.
Abstract: PROBLEM TO BE SOLVED: To provide a grain-oriented electric steel sheet having excellent coating characteristic and excellent magnetic characteristic even when MgO baked in rotary kiln is used for the main element of the annealing separating agent for a large-sized electric steel sheet coil. SOLUTION: When manufacturing MgO for the annealing separating agent of a grain-oriented electric steel sheet by using baked MgO obtained by the rotary kiln baking of magnesium hydroxide, (1) at least two kinds of baked MgO powder are mixed, (2) mixing is performed by adjusting the mixing ratio of the baked MgO according to ± deviation from the preset target value and/or the upper limit value of the permissible quantity, and (3) each target value is adjusted within a predetermined range, and the upper limit value of the permissible quantity is adjusted to be not exceeding each permissible upper limit value for MgO after mixing. COPYRIGHT: (C)2005,JPO&NCIPI
Patent•
27 Jul 2005
TL;DR: In this paper, a combination of rotary kiln and recycled fluid bed is used to burn medical garbage using combination of rotating kilns and recycling fluid bed to achieve high burning efficiency.
Abstract: This invention is burning system of medical garbage using combination of rotary kiln and recycled fluid bed. In the firebox jointly formed by rotary kiln and recycled fluid bed, rotary kiln plays the role of heat cracking and gasification, recycled fluid bed plays the role of burning out. The burning efficiency is high in recycled fluid bed. Adding limestone into the recycled fluid bed to prevent the furnace and pipeline corrosion of acidic gas such as hydrogen chloride prolongs the service life of furnace. In normal running, don't need the addition of oil for combustion-supporting, so, the operation cost is low. Quench system decreases the temperature of flue gas from 550 deg.C to 170 deg.C, reduces the generation of dioxin to prevent the secondary pollution.
Patent•
02 Nov 2005
TL;DR: In this article, a dry refractory ramming material for bottom of electric furnace and its preparation process is presented, which consists of Magnesia-calcium oxide- ferric oxide sand and high purity fused magnesia.
Abstract: The present invention is dry refractory ramming material for bottom of electric furnace and its preparation process. The dry refractory ramming material consists of magnesia-calcium oxide- ferric oxide sand and high purity fused magnesia. The magnesia-calcium oxide- ferric oxide sand is prepared with the materials including MgO, CaO, Fe2O3, Al2O3, SiO2, burnt IL and other material in certain proportion and through sintering in rotary kiln at 1700-1750 deg.c, and has density not lower than 2.5 g/cu cm. The high purity fused magnesia has critical granularity of 10 mm and accounts for 0-75 wt%. The preparation process of the dry refractory ramming material includes preparation of magnesia-calcium oxide- ferric oxide sand and grading based on Andrassen formula. The dry refractory ramming material has no cracking and high corrosion resistance and can meet the requirement of use in steel making electric furnace.
Patent•
13 Apr 2005
TL;DR: In this article, a method for pelletizing rotary kiln dust by using an alkaline aqueous solution of pH ≥ 8.5 as pelletising water to the dust recovered from the exhaust gas from the rotary Kiln for firing oxide nickel ore was proposed.
Abstract: PROBLEM TO BE SOLVED: To provide a method for pelletizing rotary kiln dust by which, when pelletizing the dust recovered from exhaust gas from a rotary kiln used for firing nickel oxide ore, pelletization characteristics can be improved and high-strength pellets which are hardly made into powder again when returned to the rotary kiln can be obtained. SOLUTION: The high-strength pellets can be obtained by adding an alkaline aqueous solution of pH ≥8.5 as pelletizing water to the dust recovered from the exhaust gas from the rotary kiln for firing oxide nickel ore. COPYRIGHT: (C)2007,JPO&INPIT
Patent•
04 Nov 2005
TL;DR: In this paper, the authors proposed an apparatus and a method for manufacturing cement where the generation of an organic chlorine compound in a cement manufacturing process can be basically suppressed and where the exhaust of the organic chlorine compounds from the cement manufacturing processes can be certainly suppressed.
Abstract: PROBLEM TO BE SOLVED: To provide an apparatus and a method for manufacturing cement where the generation of an organic chlorine compound in a cement manufacturing process can be basically suppressed and where the exhaust of the organic chlorine compound from the cement manufacturing process can be certainly suppressed. SOLUTION: The apparatus 1 for manufacturing cement comprises a calciner 26 to calcine cement raw materials, a rotary kiln 3 to make clinker by firing calcined cement raw materials in the calciner 26 and an oxygen enriched air feeding means to feed oxygen enriched air whose oxygen concentration is adjusted to be 50 vol% or more to the calciner 26 and/or the end portion of the rotary kiln 3. COPYRIGHT: (C)2007,JPO&INPIT
Journal Article•
TL;DR: In this article, the authors derived the relation between the supporting load distribution and deflection in a rotary kiln, and derived the lintern formulas for calculating the support force of the support wheels fixing on the rotate kiln.
Abstract: Kiln are the key equipment in the production of metallurgy, cement and material of fire-fast. It is the statically indeterminate system with over load, large torque and multi-support. Because of the complexity of load and stiffness distribution of the rotary kiln, the deflection of supporting center, the supporting load distribution will become seriously non-uniform. To the characters of load and stiffness distribution of the rotary kiln, the mechanical model and equation group are established, which are used to solve the variable-stiffness beam upon complex load for kiln. The relation between the supporting load distribution and deflection is derived. Accordingly, the liner formulas for calculating the support force of the support wheels fixing on the rotate kiln are obtained from the practical calculation of rotary kilns, and some useful analysis conclusions are obtained. This will provide helpful guide to condition analysis and optimization control of rotary kiln.