Showing papers on "Rotary kiln published in 2012"
TL;DR: In this article, a rotary kiln was set-up and operated in the solar furnace of DLR for thermal reduction and oxidation of cobalt oxide, with 30 cycles performed with one batch showing no evident degradation of the material.
153 citations
TL;DR: In this article, the authors proposed a procedure to produce lightweight aggregate (LWA) made of fine sediments, which were dredged from the Shihmen Reservoir in the northern Taiwan.
89 citations
TL;DR: Results demonstrate that the proposed image-based burning state recognition systems outperform other methods in terms of both recognition accuracy and robustness against the disturbance from smoke and dust inside the kiln.
Abstract: Accurate and robust recognition of burning state for sintering process of rotary kiln plays an important role in the design of image-based intelligent control systems. Existing approaches such as consensus-based methods, temperature-based methods and image segmentation-based methods could not achieve satisfactory performance. This paper presents a flame image-based burning state recognition system using a set of heterogeneous features and fusion techniques. These features, i.e., the color feature, the global and local configuration features, are able to characterize different aspects of flame images, and they can be extracted from pixel values directly without segmentation efforts. In this study, ensemble learner models with four types of base classifiers and five fusion operators are examined with comprehensive comparisons. A total of 482 typical flame images, including 86 over-burning state images, 193 under-burning state images, and 203 normal-burning state images, were used in our experiments. These images were collected from the No. 3 rotary kiln at the Shanxi Aluminum Corporation in China, and labeled by the rotary kiln operational experts. Results demonstrate that our proposed image-based burning state recognition systems outperform other methods in terms of both recognition accuracy and robustness against the disturbance from smoke and dust inside the kiln.
67 citations
TL;DR: In this article, a 3MW pyrolysis pilot plant located next to a coal-fired power plant near Vienna was set up in 2008, where an externally heated rotary kiln reactor with a design fuel power of 3MW is used which can handle about 0.6-0.8 t/h straw.
56 citations
TL;DR: In this article, an introduction to the topic of cement, including an overview of cement production, selected cement properties, and clinker phase relations, is provided, as well as an extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production.
Abstract: Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid–liquid and liquid–liquid reactions are discussed, as are the influences of particles sizes on clinker phase formation. Furthermore, a mechanism for clinker phase formation in an industrial rotary kiln reactor is outlined.
48 citations
TL;DR: In this article, an indirect heated batch rotary drum with a diameter of D = 600mm and a length of L = 450mm has been used inside the drum, a rotating and stationary measuring rod was installed, each assembled with 16 k-type thermocouples to measure the temperatures.
46 citations
TL;DR: In this article, changes in the chemical composition and morphology of deposit and lining materials in a production rotary kiln for iron ore pellet manufacture were described over a period of 8 years.
Abstract: Changes, over a period of 8 years, in the chemical composition and morphology of deposit and lining materials in a production rotary kiln for iron ore pellet manufacture are described. The followin ...
44 citations
TL;DR: A novel hybrid algorithm for fault diagnosis of rotary kiln based on a binary ant colony (BACO) and support vector machine (SVM) that outperforms existing algorithms.
Abstract: This paper proposes a novel hybrid algorithm for fault diagnosis of rotary kiln based on a binary ant colony (BACO) and support vec- tor machine (SVM). The algorithm can find a subset selection which is attained through the elimination of the features that produce noise or are strictly correlated with other already selected features. The BACO algorithm can improve classification accuracy with an appropri- ate feature subset and optimal parameters of SVM. The proposed algorithm is easily implemented and because of use of a simple filter in that, its computational complexity is very low. The performance of the proposed algorithm is evaluated through two real Rotary Cement kiln datasets. The results show that our algorithm outperforms existing algorithms.
40 citations
TL;DR: It is concluded that for the incineration of calorific wastes, rotary kilns are generally preferred and cement kilns show opportunities in improving their environmental impact when substituting their currently used fuels by more clean calorifying waste streams, if this improvement is not at the expense of the actual environmental impact.
34 citations
TL;DR: In this paper, it was shown that the degree of reduction leaves the depression region, and approaches the equilibrium values, and that the fine metals coalesce with each other via melt to grow.
Abstract: The sampling of raw materials in the rotary kiln, firing experiment by the experimental kiln, and water quenching experiment have been performed, and the clarification of behavior of the reduction and the growth of metal has been attempted by SEM-EDS. In the amorphous serpentine region, NiO has very high reducibility than FeO. The increase in heating temperature above 1 273 K allows the fine reduced metal to be confined in the silicate, which causes the extraction by the bromine methyl alcoholic solution to be difficult. This allows the degree of reduction to enter apparently the depression region. However, the increase in heating temperature above 1 525 K allows melt to occur, which causes the fine metal to coalesce with each other. Therefore, the degree of reduction leaves the depression region, and approaches the equilibrium values. Low-MgO and high-FeO·NiO silicate is enriched by the fractional crystallization, and thereafter reduction reaction is enhanced. From the result of SEM observation that metals occur from the lower temperature in the low-MgO and high-FeO ore containing much point defect, NiO and FeO in the crystal lattice are reduced via cationic and electronic defect species, the oxygen occurred diffuses toward the crystal surface via vacancies. However, the lack of experimental data of defect chemistry in Ni-ore requires the further investigation. From the fact that the temperature of the melt occurrence coincides with the temperature of metal beginning to grow largely in SEM observation, it is confirmed that the fine metals coalesce with each other via melt to grow.
29 citations
Journal Article•
TL;DR: In terms of absolute consumption, the cement industry occupies a front position in the ranks of energy consumed industries as mentioned in this paper, and the total energy costs (thermal and electrical) make up about 30 to 40 percent of the total production costs of cement.
Abstract: In terms of absolute consumption, the cement industry occupies a front position in the ranks of energy consumed industries. The total energy costs (thermal and electrical) make up about 30 to 40 percent of the total production costs of cement. This is why efficient energy utilization has always been a matter of priority in the cement industry. Cement manufactures requires very high temperatures to initiate the reaction and phase changes necessary to form the complex mineral compounds that give cement its unique properties. Pyro-processing in large rotary kiln is the operational step that provides the energy and environmental conditions necessary for the reaction and phase change. This operation dominates the energy consumption and environmental impacts associated with the manufacture of the cement. Improvement of energy efficiency reduces the emission of carbon dioxide from fuel and electricity use and may also reduce the costs of producing the cement. Process improvement may be attained by energy management, applying more energy efficient process equipment and by replacing old installations by new ones or shifting to complete new types of cement production processes, cement kiln optimization process, performing the research and development necessary to prepare and burning the alternative fuels in cement kiln and to develop new cement manufactures
TL;DR: A numerical combustion model revealed that in this case study rings are typically formed in zones of maximal radiative heat transfer, and it was proposed to increase the amount of secondary air injected to cool the oven.
Abstract: Avoiding the formation of rings in rotary kilns is an issue of primary concern to the cement production industry. We developed a numerical combustion model that revealed that in our case study rings are typically formed in zones of maximal radiative heat transfer. This local overheating causes an overproduction of the liquid phase of the granular material, which tends to stick to the oven’s wall and to form rings. To counteract for this phenomenon, we propose to increase the amount of secondary air injected to cool the oven. Experimental validation at the plant has confirmed that our solution is indeed effective. For the first time in years, the kiln has been operating without unscheduled shut-downs, resulting in hugely important cost savings.
TL;DR: In this article, a rotary kiln model is used for iron ore pelletization and the authors investigate the effect of momentum flux ratio on the flow field in general and the recirculation zone.
Abstract: Rotary kilns are used in a variety of industrial applications. The focus in this work is on characterizing the non-reacting, isothermal flow field in a rotary kiln used for iron ore pelletization. A downscaled, simplified model of the kiln is experimentally investigated using particle image velocimetry. Five different momentum flux ratios of the two inlet ducts to the kiln are investigated in order to evaluate its effect on the flow field in general and the recirculation zone in particular. Time-averaged and phase-averaged analyses are reported, and it is found that the flow field resembles that of two parallel merging jets, with the same characteristic flow zones. The back plate separating the inlet ducts acts as a bluff body to the flow and creates a region of reversed flow behind it. Due to the semicircular cross-section of the jets, the wake is elongated along the walls. Conclusions are that the flow field shows a dependence on momentum flux ratio of the jets; as the momentum flux ratio approaches unity, there is an increasing presence of von Karman-type coherent structures with a Strouhal number of between 0.16 and 0.18. These large-scale structures enhance the mixing of the jets and also affect the size of the recirculation zone. It is also shown that the inclination of the upper inlet duct leads to a decrease in length of the recirculation zone in certain cases.
Patent•
03 Oct 2012
TL;DR: A vanadium and titanium pellet ore production process, which is used for producing by using a drying grate and a rotary kiln and has the characteristic of lowering energy consumption in the process is described in this article.
Abstract: The invention discloses a vanadium and titanium pellet ore production process, which is used for producing by using a drying grate and a rotary kiln and has the characteristic of lowering energy consumption in the process. The vanadium and titanium pellet ore production process comprises the following steps of: mixing iron ore concentrate and bentonite so as to obtain a mixture; and adding an oxidation heat liberation auxiliary material into the mixture. Due to the addition of the oxidation heat liberation auxiliary material, the baking temperature of the rotary kiln can be lowered from 1,280DEG C to about 1,180 DEG C, the compressive strength of pellet ore reaches over 1,800 N/piece, drum index reaches over 90 percent and the energy consumption in a rotary kiln process is lowered by about 11 kgCe/t; simultaneously, ring formation of the rotary kiln can be reduced, the operation rate of main body equipment reaches over 90 percent and the production process is particularly suitable to be popularized and applied to the production of vanadium and titanium pellet ore.
Journal Article•
TL;DR: In this paper, a down-scaled simplified model of the rotary kiln was created and both numerical and experimental analyses of the flow field were performed, with the objective to get a deeper understanding of the aerodynamics in order to improve the combustion.
Abstract: One way to upgrade iron ore is to process it into pellets. Such a process includes several stages involving complex fluid dynamics. In this work, focus is on the grate-kiln pelletizing process and especially on the rotary kiln, with the objective to get a deeper understanding of the aerodynamics in order to improve the combustion. A down-scaled, simplified model of the real kiln is created and both numerical and experimental analyses of the flow field are performed. Conclusions are that steady state simulations can be used to get an overview over the main features of the flow field. Precautions should though be taken when analyzing the recirculation zone since steady state simulations do not capture the transient, oscillating behavior of the flow seen in the physical experiment. These oscillations will under certain conditions considerably affect the size of the recirculation zone.
Patent•
31 Oct 2012
TL;DR: A comprehensive recovery method for complicated materials containing arsenic and valuable metal slag dust, which comprises the following steps of: treating various arsenic-containing materials into a primary rotary kiln to volatilize the arsenic, and treating the materials into an SRCK for purifying the arsenic to produce arsenic products containing 995 percent of As2O3 as discussed by the authors.
Abstract: The invention relates to a comprehensive recovery method for complicated materials containing arsenic and valuable metal slag dust, which comprises the following steps of: treating various arsenic-containing materials into a primary rotary kiln to volatilize the arsenic, and treating the materials into a secondary rotary kiln for purifying the arsenic to produce arsenic products containing 995 percent of As2O3; carrying out reduction melting on primary and secondary rotary kiln slag through a blast volatilization furnace, returning produced high-arsenic smoke dust back into the primary rotary kiln for treatment, using furnace slag as cement plant raw materials and zinc raw materials for carrying out resource treatment after the forced reduction arsenic removal and zinc volatilization through a fuming furnace, carrying out alkaline oxidation refining treatment on produced arsenic containing alloy, recovering lead, antimony, bismuth, silver and the like in the arsenic removal alloy according to the conventional method, carrying out crushing alkali dissolution and filtering on refined alkali slag with 5 to 15 percent of As2O3 and about 5 to 15 percent of valuable metal content, returning slag back into the blast volatilization furnace to be treated, introducing CO2 into tin and arsenic containing solution for precipitating the arsenic, using filtered stannic oxide as high-tin raw materials to be sold, carrying out arsenic precipitating and filtering through adding Ca(OH)2 into arsenic containing filter liquor, returning calcium arsenate slag back into the primary rotary kilnfor treatment after the filtration, and evaporating and concentrating the rest alkali liquid for recovering the alkali The whole technical process of the method provided by the invention is simple and smooth, economic benefits and environment benefits are very obvious
TL;DR: In the proposed method, wavelet fuzzy inference system (WFIS) with two input variables is used as sub-model in a hierarchical structure and gradient descent algorithm is chosen for training parameters of antecedent and conclusion parts of sub-models.
Abstract: Rotary kiln is the central and the most complex component of cement production process. It is used to convert calcineous raw meal into cement clinkers, which plays a key role in quality and quantity of the final produced cement. This system has complex nonlinear dynamic equations that have not been completely worked out yet. In conventional modeling procedure, a large number of the involved parameters are crossed out and an approximation model is presented instead. Therefore, the performance of the obtained model is very important and an inaccurate model may cause many problems for designing a controller. This study presents hierarchical wavelet TS-type fuzzy inference system (HWFIS) for identification of cement rotary kiln. In the proposed method, wavelet fuzzy inference system (WFIS) with two input variables is used as sub-model in a hierarchical structure and gradient descent (GD) algorithm is chosen for training parameters of antecedent and conclusion parts of sub-models. The results show that the proposed method has higher performance in comparison with the other models. The data collected from Saveh White Cement Company is used in our simulations.
Patent•
03 Oct 2012
TL;DR: In this paper, a double-cylinder rotary kiln was used for pyrolysis garbage processing in domestic garbage with a clinker cooling machine and a predecomposition furnace to avoid the dioxin generation conditions during garbage incineration.
Abstract: The invention belongs to the technical field of environmental engineering, and provides a pyrolysis garbage technology performed by means of a double-cylinder rotary kiln. The pyrolysis garbage technology performed by means of the double-cylinder rotary kiln includes the double-cylinder rotary kiln, a cement production line and technology connection pipelines, wherein the double-cylinder rotary kiln includes a pyrolysis passage, an ash heat return passage, a kiln head cover and a kiln tail cover; the cement production line includes a cement rotary kiln, a clinker cooling machine and a predecomposition furnace; and the technology connection pipelines include a tertiary air pipeline for communicating the clinker cooling machine with the kiln tail cover, a composite gas pipeline for communicating the cement rotary kiln with the kiln tail cover, a composite gas shunting pipeline for communicating the ash heat return passage with a composite gas eduction pipe of the kiln tail cover, a waste gas waste heat pipeline for communicating a side hot air inlet of the predecomposition furnace with a waste gas exhaust connector of the kiln head cover, and a garbage slag pipeline for communicating a side feed opening of the predecomposition furnace with a garbage slag outlet of the kiln head cover. The technology is utilized for processing domestic garbage with the cement rotary kiln for cooperation, utilizes the high-temperature pyrolysis garbage cooled by cement clinker to effectively avoid the dioxin generation conditions during the garbage incineration, and effectively utilizes the heat value of garbage, and further completely utilizes the garbage ash in a recycling manner.
Patent•
05 Sep 2012
TL;DR: In this article, the authors proposed a method for upgrading coal pyrolysis, comprising the following steps: (a) sending raw coal with granularity being less than and equal to 30mm into a rotary drier, so that the raw coal and hot flue gas are connected with each other by the means of parallel flow and directly change heat.
Abstract: The invention provides a method for upgrading coal pyrolysis, comprising the following steps: (a) sending raw coal with granularity being less than and equal to 30mm into a rotary drier, so that the raw coal and hot flue gas are connected with each other by the means of parallel flow and directly change heat, and the raw coal exchanges heat indirectly with hot semicoke from a pyrolyzer in the rotary drier, to dry the raw coal; (b) mixing the dried raw coal with the high-temperature semicoke from a heating rotary kiln and sending the mixture into the pyrolyzer, wherein the coal material directly changes heat with the high-temperature semicoke and pyrolyzes to generate hot semicoke, tar steam and coal gas, wherein final pyrolyzing temperature is 500 DEG C-700 DEG C; and (c) sending a part of the hot semicoke generated into the heating rotary kiln for processing by means of heating, and sending the rest part of the hot semicoke into the rotary drier for exchanging heat directly with the raw coal. The method for upgrading coal pyrolysis has flexible operation, wide granularity range of the coal material, good quality of the generated semicoke and the generated tar, high cascade utilization of energy and high system thermal efficiency, properly solving the technical problems such as dust and tar blocking, high dust content in the tar, etc.
Patent•
19 Dec 2012
TL;DR: In this paper, a production process of pure hematite alkaline pellets is described, which consists of proportioning, proportioning and drying of hematites, bentonite and limestone.
Abstract: The invention relates to a production process of pure hematite alkaline pellets. The production process comprises the following steps of (1) proportioning: hematite, bentonite and limestone are mixed and proportioned; (2) humidification mixing: vertical mill grinding, powder selection and drying are carried out; (3) pelletizing: a disc pelletizing machine is used for pelletizing, and qualified raw pellets being 8 to 16mm enter a drying system; (4) drying: the qualified raw pellets are uniformly distributed on a grate bed of a chain grate machine through a material distribution roller sieve, and the raw pellets sequentially pass through a first drying section, a second drying section and a preheating section of the chain grate machine along the movement of the grate machine; (5) roasting: the preheated pellets enter a rotary kiln system through a discharge chute for roasting consolidation; and (6) cooling: the roasted finished pellets enter a cyclic cooling machine system for cooling. The price of raw materials is low, the smelting reduction index of a blast furnace can be effectively improved, the coke ratio is reduced, and the smelting intensity and the utilization coefficient of the blast furnace are improved.
TL;DR: In this paper, the pneumatic coal injection and combustion process in a commercial rotary kiln is modeled using a two phase flow theory approach where the gas phase is treated as a continuous phase and the pulverized coal particles are tracked in the flow field in a Lagrangian way.
TL;DR: Wang et al. as discussed by the authors presented a kiln process control expert system, with maximum temperature of pellet and gas temperature at the feed end as control cores, and interval estimate as control strategy.
Abstract: Rotary kiln process for iron ore oxide pellet production is hard to detect and control. Construction of one-dimensional model of temperature field in rotary kiln was described. And the results lay a solid foundation for online control. Establishment of kiln process control expert system was presented, with maximum temperature of pellet and gas temperature at the feed end as control cores, and interval estimate as control strategy. Software was developed and put into application in a pellet plant. The results show that control guidance of this system is accurate and effective. After production application for nearly one year, the compressive strength and first grade rate of pellet are increased by 86 N and 2.54%, respectively, while FeO content is 0.05% lowered. This system can reveal detailed information of real time kiln process, and provide a powerful tool for online control of pellet production.
Patent•
03 Jan 2012
TL;DR: In this article, a rotary kiln with an elongated cavity and a wall and a burner is used to heat the cavity, and a thermal model describing the temperature along the cavity of the kiln is presented.
Abstract: A method and a device (1 ) for controlling a process for burning lime containing mixture (CaCO3) and converting it to calcinated lime (CaO) in a rotary kiln (2), said rotary kiln (2) having an elongated cavity (3) surrounded by a wall (4) and a burner (5) arranged to heat the cavity (3). The method comprises collecting measurement data of the temperature in the wall (4) at a plurality of measuring points along the longitudinal axis (20) of said cavity (3), predicting the actual temperature gradient along the longitudinal axis (20) of said cavity (3) based at least on said measurement data of the temperature in the wall (4), and by means of a thermal model describing the temperature along the cavity (3) of the kiln (2), determining a desired temperature gradient along the cavity (3) based on the predicted temperature gradient along the cavity (3) and a predetermined control strategy controlling the temperature in the kiln (2) so that the area of deposition of lime on the inside of the walls (4) of the kiln (2) is controlled and the drawbacks of the lime deposition is reduced.
Patent•
07 Nov 2012
TL;DR: In this article, a grating-rotary kiln-based manufacturing method of Magnesian P pellets is proposed. But the manufacturing method is not suitable for high-temperature roasting and high-preheating temperature.
Abstract: A manufacturing method of magnesian pellets is particularly used in enterprises adopting a grate-rotary kiln process to manufacture the magnesian pellets. The manufacturing method of the magnesian pellets comprises ingredients by weight: 94-98% of iron powdered ore, 2-4% of high magnesium oxide (MgO) content fusing agent and 1.0-2.5% of bentonite, wherein proportion of the iron powdered ore with grain size smaller than 0.074mm is higher than 80%, and moisture content of the iron powdered ore is lower than 7.5%. The manufacturing method comprises the following steps of: evenly mixing the iron powdered ore and the high MgO content fusing agent, conducting high pressure roller-milling pretreatment, enabling the proportion of the iron powdered ore with grain size smaller than 0.005mm to be 11%-20%, and then mixing, pelletizing and roasting with the bentonite. The manufacturing method can reduce preheating temperature of the pellets, simultaneously, can further improve strength of the pellets to enter a rotary kiln, shortens high-temperature roasting time and solves the technical problems of high preheating temperature, low pellet preheating strength and long high-temperature roasting time when the MgO pellets are manufactured.
Patent•
21 Nov 2012
TL;DR: In this article, a special composite firebrick for a rotary kiln and a preparation method thereof are described, which can be used for building the inside linings of a rotating kiln.
Abstract: The invention relates to a special composite firebrick for a rotary kiln and a preparation method thereof. The special composite firebricks are divided in to common firebricks and special firebricks which are in the same appearance and size, both the common firebrick and the special firebrick consist of working layers (1) and thermal insulation layers (2), and adhesion agents and binding agents are combined between the working layers (1) and thermal insulation layers (2); the adhesion agents are prepared by mixing fluorite powders, hollow microspheres, sub-white fused alumina hollow spheres, mullite hollow spheres, sphere clay powders and silica fumes according to certain proportions to form slurry by utilizing inorganic bonds; the binding agents are inorganic bonds, such as one or mixture of phenolic resin glue, polyvinyl acetate resin glue and urea resin. The special composite firebrick for the rotary kiln can be used for building the inside liner of a rotary kiln calcined by cement, fireproof material, fracturing propping agent for petroleum well, lime and the like, and has the functions of strip resistance, thermal shock resistance, high refractoriness under load and wear resistance.
Patent•
12 Dec 2012
TL;DR: In this paper, an incinerator of a waste rotary kiln is described, and the secondary burning chamber and the G-G heat converter are connected through a flue.
Abstract: The utility model discloses an incinerator of a waste rotary kiln. The incinerator comprises the rotary kiln, a secondary burning chamber, a G-G heat converter, a water-cooling cyclone dust collector, a semi-drying quenching tower, a dry spraying device, a bag dust collector, a nanometer electrostatic adsorption device, an induced draft fan and a spray washing tower. The rotary kiln and the secondary burning chamber are connected in combined mode, and the secondary burning chamber, the G-G heat converter, the water-cooling cyclone dust collector, the semi-drying quenching tower, the dry spraying device, the bag dust collector, the nanometer electrostatic adsorption device, the induced draft fan and the spray washing tower are sequentially connected through a flue. The incinerator of the waste rotary kiln can effectively disposing of solid waste, harmful gas produced in a disposing process is not discharged to the outside directly, tail gas can be up to standard through cooling, quenching, dust removing and absorption, generated hot wind is recycled as oxygen supplement wind of the rotary kiln, working frequency of the rotary kiln is improved, and energy is saved.
Patent•
03 Oct 2012
TL;DR: In this paper, a method for enhancing the intensity of ground hematite pellet preheated pellets was proposed, which consists of a burdening process, a mixing process and a pelletizing process.
Abstract: The invention relates to a method for enhancing the intensity of ground hematite pellet preheated pellets. The method comprises a burdening process, a mixing process, a pelletizing process, a distributing process and a baking process and is characterized in that: a process for pretreating ground hematite by using a high-pressure roller mill is performed; the pressure of the high-pressure roller mill is between 3 and 6 MPa; and the ground hematite is pretreated under an appropriate process parameter condition through the high-pressure roller mill pretreating process, so that the preheating temperature of a pellet is lowered to be below 1,000 DEG C and the intensity of a preheated pellet entering a rotary kiln reaches over 400 N/pellet. The method is particularly suitable for an enterprise which produces the pellet by taking the ground hematite as a raw material by a chain grate-rotary kiln process, can effectively solve the problem of high preheating and baking temperatures existing inthe preheating and baking processes of hematite concentrate pellets and the problems of high requirements on equipment materials, production operation and the like in the practical production process, which are caused by the high preheating and baking temperatures, and realizes production of oxide pellets for iron making by efficiently utilizing the ground hematite.
Patent•
20 Jun 2012
TL;DR: In this article, a method for firing sludge into haydite rotary kiln by a conveyer is described. But the method is not suitable for granulating sludge, and the sludge is not dried before granulating.
Abstract: The invention provides a method for firing sludge into haydite. The method comprises the following process flows of: reducing water content of sludge to 45-55% by geotube or other dewatering modes, mixing the sludge with a clay raw material at a volume ratio of 1:1, granulating, conveying to a haydite rotary kiln by a conveyer for firing. According to the invention, the sludge is not dried before granulating, and the sludge, of which the water content is reduced to about 50% by the geotube or other dewatering modes, is mixed with clay at a proper ratio and then directly extruded and granulated, thus the energy consumption is reduced, the treatment capacity of the rotary kiln is high, and the resource utilization of the sludge is effectively realized.
Patent•
15 Jun 2012
TL;DR: In this article, a method for detecting straightness deviations and/or deformations in a rotary kiln is presented, in which the outer cylindrical surface of the rotating cylinder, the tires, the rollers, and the shafts of the roller are scanned without contact by means of at least one scanning device.
Abstract: The invention relates to a method for detecting straightness deviations and/or deformations in a rotary kiln (1), the rotating cylinder (4) of which has tires (6) arranged at a distance from one another in the axial direction, which tires are respectively supported on rollers (7). In said method, the outer cylindrical surface (5) of the rotating cylinder (4), the tires (6), the rollers (7), and/or the shafts (17) of the rollers (7) are scanned without contact by means of at least one scanning device (12), such that three-dimensional position data are obtained regarding the scanned objects, and the three-dimensional position data are evaluated with regard to the occurrence of a deviation of the rotary kiln axis (3) from a straight line, a deviation of the rotating cylinder (4) from a cylindrical shape, and/or a deviation of the roller rotational axes (8) from a line parallel to the rotary kiln axis (3). For a device for detecting straightness deviations and/or deformations in a rotary kiln (1), at least one scanning device (12) that operates without contact is provided, which scanning device is arranged in order to scan the outer cylindrical surface (5) of the rotating cylinder (4), the tires (6), the rollers (7), and/or the shafts (17) and/or shaft end extensions of the rollers (7) without contact.
Patent•
29 Aug 2012
TL;DR: In this paper, a two-in-one carbonization-activation integrated activated carbon production apparatus is described, in which a movably connected steam jacket is added outside a rotary kiln, the bottom of the jacket is a firebox, the top of jacket is an insulating water tank, steam pockets are arranged on the water tank and a discharge screw conveyer is designed on the other end of the rotary Kiln.
Abstract: The purpose of the invention is to provide a carbonization-activation integrated activated carbon production apparatus. The structure of a conventional activated carbon furnace is improved, so that the two-step method in which first carbonization and then activation are carried out on the activated carbon is changed into a manner that carbonization and activation are completed in one system, two-in-one furnace for short. The carbonization-activation integrated activated carbon production apparatus is characterized in that a movably connected steam jacket is added outside a rotary kiln, the bottom of the jacket is a firebox, the top of the jacket is an insulating water tank, steam pockets are arranged on the water tank, an automatic feeder is designed on one end of the rotary kiln, a discharge screw conveyer is designed on the other end of the rotary kiln, dried and weighed material is carbonized and activated and is fed from one end of the rotary kiln in a clockwise rotating manner, the activated material is discharged out from the other end of the rotary kiln in a counterclockwise rotating manner, the production is intermittent, the material is dried by residual heat after heat exchange, and intermediate steps are reduced. The process is suitable for the production of activated carbon with various activity requirements, and the stability of product quality is favorably enhanced, heat energy is effectively recycled, the production process is shortened, energy consumption is reduced, the heat efficiency is increased, and novel production process equipment is provided for the production of various specifications of activated carbon.