Roller Kiln Research Articles

Pure Ammonia-Fueled Roller Kiln for the Production of Ceramic Tiles: A First Demonstration

Pure Ammonia-Fueled Roller Kiln for the Production of Ceramic Tiles: A First Demonstration

Residues from beneficiation of granite in porcelain stoneware: Effects on technological properties

Granite extraction waste represents an interesting alternative material for porcelain stoneware production, but information on its influence presents several gaps. For this reason, two different wastes were selected: a coarser iron-rich material from magnetic separation and a finer one from conveyance and abatement systems. Both were physically and chemically characterized. Batches were formulated by partial substitution of feldspar and technological behaviour of bodies was assessed by simulating the industrial manufacture at laboratory scale. Tiles were shaped by uniaxial pressure and fired by fast firing in electric roller kiln. The effect of waste addition was evaluated during the whole production process. Fired samples were characterized in terms of technological properties, mineralogical composition and microstructure evolution. The formulation optimization reduces firing temperature getting commercial technological constraints. A further increase of finer waste content affects compaction and mechanical strength. The presence of micaceous particles after the firing process may act as cracks initiation.

Physics-informed data-driven model of dehydration reaction stage in the sintering process of ternary cathode materials

The sintering process is the main process that affects the performance of ternary cathode materials. Due to the closed, continuous, and long-term characteristics of the sintering process carried out in a roller kiln, the reaction state including reaction degree, particle size, and etc., of the raw materials cannot be directly obtained through sampling detection, resulting in ineffective temperature control. This article mainly focuses on modeling the dehydration reaction stage of the sintering process to obtain the reaction state of the raw materials. Firstly, a two-sphere model is established based on Newton’s second law and the particle volume conservation equation to describe the relationship between the particle radius and sintering temperature of lithium hydroxide and ternary precursor; Secondly, the chemical kinetic parameters of the dehydration reaction in the two-sphere model are obtained by combining the single heating rate scanning method with the multiple heating rate scanning method; Then, in order to improve the accuracy of the two-sphere model and reduce the impact of external environmental temperature changes, a physics-informed neural network model is constructed by combining the two-sphere model with the neural ordinary differential equation model. Finally, the effectiveness of the modeling method is verified through numerical simulation and empirical data.

ADP-Based Event-Triggered Constrained Optimal Control on Spatiotemporal Process: Application to Temperature Field in Roller Kiln.

The precise control of the spatiotemporal process in a roller kiln is crucial in the production of Ni-Co-Mn layered cathode material of lithium-ion batteries. Since the product is extremely sensitive to temperature distribution, temperature field control is of great significance. In this article, an event-triggered optimal control (ETOC) method with input constraints for the temperature field is proposed, which takes up an important position in reducing the communication and computation costs. A nonquadratic cost function is adopted to describe the system performance with input constraints. First, we present the problem description of the temperature field event-triggered control, where this field is described by a partial differential equation (PDE). Then, the event-triggered condition is designed according to the information of system states and control inputs. On this basis, a framework of the event-triggered adaptive dynamic programming (ETADP) method that is based on the model reduction technology is proposed for the PDE system. A critic network is used to approach the optimal performance index by a neural network (NN) together with that an actor network is used to optimize the control strategy. Furthermore, an upper bound of the performance index and a lower bound of interexecution times, as well as the stabilities of the impulsive dynamic system and the closed-loop PDE system, are also proved. Simulation verification demonstrates the effectiveness of the proposed method.

Optimum phosphate ion removal from aqueous solutions using roller kiln industrial solid waste

Water scarcity is the most imperative predicament that concerns the population. In this research, a roller kiln (RK) industrial solid waste was used in the adsorption of phosphate ions from aqueous solutions thus converting a waste to wealth through aiding in serving as a water treatment application. The RK waste was produced from an Egyptian factory with a flow rate of million tons/day. Surface characterization for this solid waste was performed including transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infra-red (FTIR), zeta potential (ZP), and particle size distribution (PSD). Based on the kinetics and isotherm studies, the pseudo first order (PFO) kinetic model and Freundlich isotherm model were the best-fitted models with the experimental data as well as the Dubinin–Radushkevich isotherm model indicated that the adsorption type was physical. The attained experimental results were then optimized to attain the experimental conditions at which the optimum adsorption percentage was achieved using response surface methodology (RSM). The optimum percentage removal of phosphate ions 99.5 (%) was achieved at the following experimental conditions; pH 8, temperature = 25 °C, contact time = 9 min, initial phosphate ion concentration = 10 mg/L and adsorbent dose 0.5 = g/L.

Effect of nucleating agent additions on gahnite based glass-ceramic glazes

The effect of ZrO2 and TiO2 addition in gahnite-based glass-ceramic glazes was investigated by equimolar nucleating agents substituting 5 mol% SiO2. The effect of this substitution on thermal behavior was studied by means of differential thermal analysis and hot stage microscopy. The sintering behavior of samples changed with the type of nucleating agent added. Compacted samples sintered between 850 and 1200 °C for 2 min at 40°Cmin−1 heating and cooling rate for determining the crystallization sequence with using X-ray diffraction. Prepared glaze samples fired at 1180 °C for 6 min in the industrial roller kiln. Total firing time is 58 min from cold to cold. The effect of nucleating agent additions of gahnite-based glass-ceramic glazes was investigated by X-ray diffraction, scanning electron microscopy, spectrophotometer, and gloss meter. Glaze without nucleating agents shows heterogeneous surface crystallization from the frit surface to the inside with dendritic gahnite growth. With the nucleating agent, volume crystallization was seen with phase separation or seeding effect, which depends on the type of nucleating agent. Glaze with TiO2 has two different morphology; one region has fine gahnite crystals below 100 nm, and another region has clusters of nano gahnite crystals in flake-like morphology. ZrO2 provides fine gahnite crystallization, which is smaller than 80 nm. While ZrO2 added glaze is translucent, the other glazes are opaque due to different crystal sizes. It is observed that nano crystallization has a positive effect on pore swelling behavior due to its high crystal surface area. With the addition of the ZrO2 and TiO2, fine-sized nanocrystalline gahnite based glass-ceramic glazes can be obtained for the first time in industrial fast-firing conditions.

Event-Triggered Optimal Control for Temperature Field of Roller Kiln Based on Adaptive Dynamic Programming.

Temperature field control is crucial for the comprehensive performance of Ni-Co-Mn layered cathode material that is the most important part of lithium-ion batteries. Starting from the aspect of a class of distributed parameter systems described by highly dissipative partial differential equations (PDEs), an event-triggered optimal control (ETOC) method based on adaptive dynamic programming (ADP) for the roller kiln temperature field is proposed. First, we formulate the event-triggered control problem of the temperature field under the general framework of PDE systems. Then, an event-triggered condition is designed based on the stability of the closed-loop PDE system, which also guarantees the upper bound of the performance index. Subsequently, ADP technology is adopted to realize the ETOC, where the critic network is employed to approximate the optimal value function. Since the studied system can be regarded as an impulsive dynamic system with flow dynamics and jump dynamics simultaneously, the stability of the impulsive dynamic system combined with the ADP-based closed-loop PDE system is proved. Finally, simulation results on the temperature field verify the effectiveness of the proposed method.

Corrosion resistance of calcium hexaaluminate insulating firebrick for synthesising ternary lithium-ion battery cathode materials

The widespread use of ternary lithium-ion battery cathode Li(NixCoyMn1−x−y)O2 (LNCM) materials in energy storage equipment has resulted in an increase in the demand for insulating refractory of roller kiln. However, the severe corrosion during LNCM calcination will result in desquamate and damage of the insulating refractory. In this study, the corrosion resistance of bubble alumina brick (bubble alumina), mullite and CA6 (calcium hexaaluminate) insulating refractories was thoroughly investigated. This study combined the laboratory scale experiments on the interfacial reaction and after life cycle analysis on industrial insulating refractory to investigate the interactions between the insulating refractories and LNCM precursor mixture powders after the calcination temperature of 950 °C for 10 h and the corrosion behaviour of the LNCM precursor to different insulating fire bricks after the heat treatment temperature of 950 °C for 10 h every time and repeated 10 times according to the actual LNCM preparation system. The phase composition and microstructure of the three insulating refractories before and after corrosion were characterised to obtain a comprehensive understanding of the corrosion mechanism and behaviour. Results showed that the CA6 has excellent corrosion resistance and has the potential to be used in the lithium battery industry.

The Effect of Roll Maintenance Costs on Kiln Machines on the Efficiency of Expenditure on PT. XYZ

XYZ is a company engaged in the ceramics industry. One way maintenance is carried out on production machines is to use the cost of maintenance expenditure which aims to streamline and expedite the production process of both quality and quantity. In this study the cost pemeliharaan yang done is on a production machine roller kiln kiln mainly because if not maintained can quickly roll the kiln was dirty and broken so that it can directly increase the cost of expenditures (the smaller the efficiency of expenditures) for the purchase of a new kiln roll to replace the roll kiln dirty and broken. The method used in this study to determine the effect of roller kiln maintenance costs on the efficiency of spending is a statistic that is a quantitative method with simple linear regression (two variables). From the research results obtained regression equation y = 0.379 +1.110 X diliat coefficients table from SPSS, Efficiency of expenditure will be worth 0.379 if the company no roll maintenance costs. Each one-time increase in the cost of engine maintenance roll kiln then the efficiency corporate spending rose by 1.110. The cost of engine maintenance roll kilns have strong relationships with significant spending efficiency by 97.9% results from SPSS can diliat model summary table, the efficiency of spending can be influenced by other factors is the use of EUT. Average roll kiln is unplugged as much as 105.73 in round roll 106 at a price of Rp 300,000 a roll when not using the average maintenance cost per month can pay for purchases of new roll of 106 x 300 000 = 31.8 million. If using the maintenance costs (usage Grinding stone) at a price of Grinding stones, Rp. 1.800.000 to clean up the dirty roll kiln as many as 100-150 stems roll is clearly more efficient in spending compared With no use of maintenance costs

Multi-objective optimization and off-design performance based on thermodynamic -economic-environmental analysis of organic Rankine & Kalina cycles for roller kiln waste heat recovery

ABSTRACT Heat recovery from roller kiln’s flue gas and cooling gas is interest topic to make ceramic tile production cleaner and more sustainable. Comparatively, the parallel double-evaporator regenerative organic Rankine cycle (PD-RORC) & Kalina cycle (PD-KC34 (Kalina cycle 34)) provide a good solution for a roller kiln’s low-temperature double heat sources utilization. In this research, the off-design performance of the multiobjective optimized PD-RORC & PD-KC34 based on thermodynamic-economic-environmental model is investigated to provide dependable assessment for the roller kiln’s waste heat recovery. Firstly, the multiobjective optimization of PD-RORC & PD-KC34 is carried out considering thermodynamic, economic and environmental factors, and TOPSIS method is used to select the optimal Pareto solution. Then, the influences of the roller kiln’s operating conditions and heat sink on the off-design performances of PD-RORC & PD-KC34 are further explored. The results show that, under the optimal condition, PD-RORC has superior exergy efficiency () and environmental performance with of 49.76% and environment impact load () of 0.096 mPEChina,90/kWh while PD-KC34 has better net power output () and economic behavior with of 250.72 kW and electricity production cost () of 0.090 $/kWh. In addition, excess air coefficient has the greatest impact on , , and for PD-RORC and PD-KC34. On the whole, PD-KC34 has higher sensitivity on and while PD-RORC shows greater sensitivity on and .

Thermo-economic investigation and optimization of parallel double-evaporator organic Rankine & Kalina cycles driven by the waste heat of an industrial roller kiln: A comparative study

The roller kiln is characterized by significant heat losses mainly caused by flue gas and cooling gas accounting for 70%. In this study, four novel power cycles including a basic organic Rankine cycle (BORC), a regenerative organic Rankine cycle (RORC), a Kalina cycle11 (KC11) and a Kalina cycle 34 (KC34) with the parallel double-evaporator (PD) configuration are proposed for dual-level waste heat recovery for a roller kiln. To identify the superiority system, the recommended power cycles are assessed and compared from an integrated thermodynamic and economic perspective. The impacts of the basic operating parameters on net power output, exergy efficiency, electricity production cost and savings to investment ratio are discussed. Meanwhile, the single-, bi- and three-objective optimizations are conducted and the optimal solutions are compared. The results indicated that for the considered optimization models, PDKC34 achieved the highest net power output of 211.06–224.45​ kW and thermal efficiency of 20.02–21.20%, PDBORC had the best economic performance on electricity production cost of 0.0875–0.0932 $/kWh, payback period of 5.709–6.210 year and savings to investment ratio of 2.191–2.335 while PDRORC with R-141b possessed the best exergy efficiency of 45.11–49.17%. On the whole, the four thermodynamic cycles contributed to the best thermodynamic performance in the maximizing net power output model while these had the best economic performance in the minimum EPC model. Besides, the evaporation unit had the highest impact on exergy destruction and total investment cost among all components for the studied optimization models.

Comparative environmental impacts and emission reductions of introducing the novel organic Rankine & Kalina cycles to recover waste heat for a roller kiln

Abstract In order to simultaneously utilize the flue gas and cooling gas of a roller kiln, the novel organic Rankine (ORC) & Kalina cycles (KC) with parallel double-evaporator (PD) including PD-BORC, PD-RORC, PD-KC11 and PD-KC34 are introduced for the waste heat recovery. To evaluate the environmental influences performance for the recommended thermodynamic cycles, environment impact loads and emission reductions analysis are employed from the life-cycle perspective. Also, to select a more environmentally friendly model, the system environmental influences based on thermodynamic, economic, environmental and watery criteria are investigated. Results show that under the four criteria, the pump contribute mostly to GWP (global warming potential), AP (acidification potential), EP (eutrophication potential) and HTP (human toxicity potential), evaporation unit is dominant in POCP (photochemical ozone creation potential) and SWP (solid waste potential), and both evaporation unit and pump have the main influence on SAP (soot and dust potential). Meanwhile, operation phase makes the greatest contribution to GWP, AP and HTP, construction phase has the greatest influence on POCP and SWP, and construction and operation phases account for the largest proportion of EP and SAP. It can also be concluded that SAP has the most serious impact on the environment while POCP is the least significant factor. Besides, from the perspective of environment impact load, PD-BORC is the best selection, and the system design based on environmental criterion has the minimum value. Also, in terms of the emission reduction, PD-KC34 is the priority selection, and the maximum emission reduction can be achieved under thermodynamic criterion. Furthermore, the reduction ratio of environment impact load can be increased with increasing the evaporator inlet temperature, decreasing the condenser outlet temperature, increasing the superheat degree (PD-ORCs) and decreasing the superheat degree (PD-KCs), and decreasing the ammonia concentration (PD-KCs).

Waste minimisation of ceramic wall tiles

Many wastes are commonly produced during the ceramic tiles manufacturing process such as: Roller kiln grinding waste, cyclone dust waste, and ceramic sludge. Those wastes are landfilled because they have been predictable to be less conducive to recycling. In this study, the recyclability of the mentioned wastes is enhanced to minimize natural resource consumption, save energy, reduce cost and decrease hazards to the surrounding environment. Three types of collected wastes were added in different ratios to a standard wall tile mix and factorial 23 design techniques was used to investigate the effect of adding these wastes in different ratios on the properties of unfired and fired bodies. Suggested recipes were shaped in standard tile form, dried and fired at 1,160 oC for 15 min. Tests performed on these tiles revealed that they abide by standard requirements for ceramic wall tiles.

Analysis of energy saving in domestic ceramic industry kilns

Ceramic industrial kiln refers to the combustion equipment for ceramic production, which generally refers to roller kiln, shuttle tunnel kiln and shuttle kiln. Roller kiln refers to the kiln with continuous firing and rotating roller as the vehicle of the billet body; Tunnel kiln refers to the kiln which adopts continuous firing and takes rail kiln car as the transport vehicle of billet body. Shuttle kiln refers to the kiln which is fired intermittently and consists of kiln car, kiln chamber and kiln door. Factors influencing energy saving of kiln include construction materials, kiln structure, combustion technology, thermal insulation performance and automation control.

Thermal Performance Combined with Cooling System Parameters Study for a Roller Kiln Based on Energy-Exergy Analysis

Roller kilns, characterized as high energy consumption equipment, are widely used in the firing process of ceramic tiles. To evaluate the thermal performance of a roller kiln, a detailed energy and exergy analysis is carried out employing the operating values from a typical ceramic factory. In this study, parametric studies are performed that examine the impacts of the roller kiln’s cooling system on thermal performance, fuel-saving, cost-saving, and environmental influence. The results show that the targeted energy only accounts for 13.4% and 9.7% of the total energy and exergy inputs, indicating the poor efficiency of the roller kiln. This research also identifies that the exergy destruction is the largest cause of the exergy loss in the system, accounting for 85.1% of the total exergy input—of which 50.9% is due to heat and mass transfer, and 37.9% is caused by fuel combustion. Based on the parametric studies, it has been found that with every 1% increase in cooling air mass flow, the energy and the exergy efficiencies of the kiln increase by 0.06% and 0.04%; with every 1% increase in cooling gas temperature, the energy and the exergy efficiencies of the kiln drop by 0.09% and 0.07%; with every 1% increase in cooling gas residence time, the energy and the exergy efficiencies of the kiln increase by 0.16% and 0.12%. Furthermore, results show that the cooling air residence time has the main impact on the cost-saving and carbon dioxide emission reduction, followed by cooling air mass and cooling air temperature.

A Dynamic Grey-Box Model and its Application in the Sintering Process of Ternary Cathode Material

Soft-sensor technique is often used to estimate key variables in industrial manufacturing, of which the commonly used approaches as the first-principle modeling and data-driven modeling both have their limitations. To take full advantage of the modeling methods and overcome the problems of unmodeled dynamics in industrial manufacturing, a grey-box modeling method combining the first-principle analysis with dynamic data-driven model is developed in this paper. In the framework of the presented grey-box model, the unmodeled dynamics in the first-principle model are obtained by the dynamic probabilistic latent variable model. On this basis, availability of models can be improved. Finally, the actual industrial data in the roller kiln of ternary cathode material manufacturing is used for simulation to verify the validity of the model. The results have practical guiding significance.

Recycling Of The Mixture Resulted From Sanitary Ware Waste, Roller Kiln Waste And Ceramic Tiles Sludge Waste In The Manufacturing Of Ceramic Floor Tiles

Ceramic tiles industry is a big source for wastes that have a bad effect on the environment. The first source of waste is associated with roller kilns as it needs a periodic surface grinding to its rollers which results in a waste powder. The second type of waste is ceramic tiles sludge which produced from a water treatment plant. The third waste is sanitary ware waste which coming out from sanitary ware industry. The main aim of this paper is to investigate the ability of substituting part of the main body mixture of floor tiles by these three types of waste powder. Many Experiments were done on the raw materials. Rectangular tile specimens were moulded, dried and fired. Sintering parameters and mechanical properties were determined. The sample that consist of 2% Roller Kiln, 39% Ceramic tiles sludge, 15% sanitary ware waste, and 44% Floor tiles mixture has the optimum properties.

Galvanic sludges: Effectiveness of red clay ceramics in the retention of heavy metals and effects on their technical properties.

Abstract Tiles of red clay mixed with 5% by weight of galvanic sludge were obtained by dry pressing, enameling in the line of production, and sintering in a semi-industrial roller kiln. In the process, a 30-minute firing cycle was employed at a temperature of 1170°C, with heating–cooling ramps between 47°C and 197°C. In order to estimate the effects of the addition of galvanic sludge on the finished product, the technical properties of the material were evaluated: loss by calcination, water absorption, linear shrinkage, three-point flexural strength, color, and spectroscopy characterization via IFTR, UV–Vis–NIR, and RAMAN, and ceramic-mount microstructure and crystal structure via XRD. The effectiveness of the ceramic for the retention of Cu, Ni and Cr was determined from the leaching test, in order to characterize the toxicity (TCLP) of the finished and ground samples according to EPA 1311. As a result, it was determined that the addition of sludge to the clay modified the color of the finished product, decreased the flexural strength, and increased the shrinkage and the total porosity. Therefore, the sintered product acted satisfactorily as an encapsulating agent.

Temperature prediction for roller kiln based on hybrid first-principle model and data-driven MW-DLWKPCR model

In this paper, a hybrid temperature prediction model is developed for an industrial roller kiln of lithium-ion battery cathode materials, which is based on first-principle model and moving window-double locally weighted kernel principal component regression (DLKWKPCR). First, the mechanism model is built for the roller kiln according to the energy conservation law and heat transfer mechanism. Since the first-principle model is based on some simplified assumptions, it often results in large estimation errors. Thus, a data-driven error compensation model is further constructed with real-time process running data. In order to handle the strongly nonlinear, highly redundant and gradually time-varying characteristics, the error compensation model is built with moving window based DLWKPCR. Finally, a hybrid temperature prediction model is obtained by combining the compensation model and the mechanism model. An industrial roller kiln is utilized to test the effectiveness of the hybrid prediction model, in which the modeling results demonstrate that the developed hybrid prediction model can correctly estimate the roller kiln temperature.

Application of A High Efficiency Composite Denitration Agent in Ceramic Roller Kiln Flue Gas Treatment: A Case Study

With the increasing stringent environment pollution emission standards, the ceramic industry is facing a great challenge of NOx control. The research and application of highly efficiency deNOx technologies for ceramic roller kiln are benefit both to ceramic industry and environmental protection. Selective non-catalytic reduction (SNCR) is among the leading edge of the hotspot of NOx control. However, most of the reported investigations were laboratory scale study, which were limited to representing the performance of SNCR denitration agent at real application. In this study, we compared the performance of a self-made denitration agent with traditional ones, and the effect of spraying rate and position on NOx removal efficiency were investigated at a 20000 m2/h ceramic product line. Besides, a continuous experiment was carried out. By the work conducted in a real gas, a number of first-hand data focusing on SNCR technology for deNOx of ceramic roller kiln and its possibility of coupling with existed wet absorption process were shared in this paper.