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Öğe 3.5 d temperature model of a coal stockpile(TAYLOR & FRANCIS INC, 2008) Ozdeniz, A. H.; Corumluoglu, O.; Kalayci, I.; Sensogut, C.Overproduced coal mines that are not sold should remain in coal stock sites. If these coal stockpiles remain at the stock yards over a certain period of time, a spontaneous combustion can be started. Coal stocks under combustion threat can cost too much economically to coal companies. Therefore, it is important to take some precautions for saving the stockpiles from the spontaneous combustion. In this research, a coal stock which was 5 m wide, 10 m long, and 3 m in height, with a weight of 120 tons, was monitored to observe internal temperature changes with respect to time under normal atmospheric conditions. Internal temperature measurements were obtained at 20 points distributed all over the two layers in the stockpile. Temperatures measured by a specially designed mechanism were then stored into a computer every 3 h for a period of 3 months. Afterward, this dataset was used to delineate 3.5 D temporal temperature distribution models for these two levels, and they were used to analyze and interpret what was seen in these models to derive some conclusions. It was openly seen, followed, and analyzed that internal temperature changes in the stockpile went up to 31 degrees C by 3.5 D models created for this research.Öğe Combustion characteristics of 24 lignite samples(TAYLOR & FRANCIS INC, 2008) Sensogut, C.; Ozsen, H.; Demirbas, A.In this study, the combustion characteristics such as thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTGA), burning profile, ignition temperature, and peak temperature were analyzed for 24 lignite samples from different areas of Turkey. The samples were heated up to 900 degrees C at a constant rate of 10 degrees C/min in a 5 mL/min flow of dry air. The burning profiles of the samples studied, combined with proximate, sulfur analysis and calorimetry results, contribute to a clearer identification of lignite samples' structure and a better understanding of the coalification process. The lignite samples have been tested with particle size of 0-0.05 mm. Ignition temperatures of the samples have been determined from their burning profiles.Öğe Decrease of calorific value and particle size in coal stockpiles(TAYLOR & FRANCIS INC, 2008) Sensogut, C.; Ozdeniz, A. H.During storage of excess amount of coal, they lose both their economical value and cause environmental problems. In this work, two industrial-sized stockpiles were constituted at a coal stockyard of Western Lignite Corporation (WLC) in Tuncbilek, Turkey. The size of the stockpiles, formed as triangle prisms, was about 10 m 5 m wide with a height of 3 m; each mass being approximately 120 tons of coal in total. Some of the parameters that were effective on the stockpiles were measured in a continuous manner during this experimental work. The calorific losses and the decreases that occurred in particle size due to atmospheric conditions were also examined and detailed as the result of this work.Öğe Evaluation of Noise Measurements Performed in Mining Sites for Environmental Aspects(UNIV TEHRAN, 2013) Cinar, I; Sensogut, C.In this study, results of noise level measurements performed in 4 different mining sites are given. Noise level measurements performed in opencast mining site of Konya Ilgin Lignite Corporation (ILC), in Konya Eyak Mining quarry site and in Aydin Cine Feldspar ore dressing facility have been evaluated together with worker surveys. The noise level measurements performed in Manisa Soma Uyar Mining coal preparation facility have been evaluated in terms of machine-work performance. Thence, it has been pointed out that the increase in noise was due to machine faults. When the measurement results were considered, it is mandatory for the workers to use protective equipment. Workers working under high noise level would be affected physically, physiologically and psychologically. To prevent these harms, they should be encouraged to use earmuffs and plugs.Öğe Modeling of coal stockpiles using a finite elements method(TAYLOR & FRANCIS INC, 2008) Ozdeniz, A. H.; Sensogut, C.In the case of coal stockpiles finding suitable environmental conditions, spontaneous combustion phenomenon will be unavoidable. In this study, an industrial-sized stockpile having a shape of triangle prism was constituted in a coal stockyard of Western Lignite Corporation (WLC), Turkey. The parameters of time, humidity and temperature of air, atmospheric pressure, velocity and direction of wind values that are effective on coal stockpile were measured in a continuous manner. These experimental works were transferred into a computer media in order to obtain similar outcomes by carrying out 2-dimensional analysis of the stockpile with Finite Elements Method (FEM). The performed experimental studies and obtained results were then compared.Öğe Monitoring and ANN modeling of coal stockpile behavior under different atmospheric conditions(TAYLOR & FRANCIS INC, 2008) Ozdeniz, A. H.; Ozbay, Y.; Yilmaz, N.; Sensogut, C.In this study, an industrial-sized stockpile of 5 m width, 4 m height, and 10 m length was built in a coal stock area to investigate coal stockpile behavior under different atmospheric conditions. The effective parameters on the coal stockpile that were time, weather temperature, atmospheric pressure, air humidity, velocity, and direction of wind values were automatically measured by means of a computer-aided measurement system to obtain Artificial Neural Network (ANN) input data. The coal stockpiles, which should be continuously observed, are capable of spontaneous combustion and then causing serious economical losses due to the mentioned parameters. Afterwards, these measurement values were used for training and testing of the ANN model. Comparison of the experimental and ANN results, accuracy rates of training, and testing were found as 98.6% and 98.7%, respectively. It is shown that possible coal stockpile behavior with this ANN model is powerfully estimated.Öğe The relation between hydrophobic flocculation and combustion characteristics of coal(ELSEVIER, 2015) Duzyol, S.; Sensogut, C.The hydrophobic flocculation of the lignite obtained from the Ermenek region was investigated under the different operating parameters such as pH, sodium silicate concentration and kerosene concentration in the present work. Determination of combustible recovery, ash content and zeta potential values were utilized in order to make sense of the hydrophobic flocculation behavior. To specify indirectly the hydrophobicity degree of the coal, contact angle measurements were performed on the flocks obtained from the experiments. The combustion characteristics of coal such as thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTGA), ignition temperature, and peak temperature were analyzed and correlated with the hydrophobic flocculation. In consequence, optimum pH value was determined as to be 4; optimum sodium silicate and kerosene concentration were also ascertained as to be 1 kg/t and 16 kg/t, respectively. When experimental conditions were set up optimally, the flocks were obtained with combustible recovery of 90% and ash content of 9.8%. The strong correlation was observed between the hydrophobic flocculation results and ignition temperatures and peak temperatures acquired from the DTGA curves. The surface tension of solution, however, showed no remarkable changing. It was confirmed that the contact angle values ranged from 114 degrees to 130 degrees and the surfaces were highly hydrophobic. (C) 2015 Elsevier B.V. All rights reserved.Öğe A statistical study on thermogravimetry of some coals in Turkey(TAYLOR & FRANCIS INC, 2008) Sensogut, C.; Yildirim, O. S.; Cinar, I.; Ozdeniz, A. H.A number of physical features of coal can be determined as the function of temperature by the utilization of thermal treatment applied to coal itself. The most common techniques encountered in literature on this matter are differential thermal analysis, thermogravimetric analysis, and differential thermogravimetric analysis. In this article, the thermogravimetric behavior and physicochemical characteristics of some Turkish coals have been defined. Additionally, the relationship between these characteristics of the coal samples has also been given in a statistical manner.Öğe Temperature profiles of coal stockpiles(TAYLOR & FRANCIS INC, 2008) Sensogut, C.; Ozdeniz, A. H.; Gundogdu, I. B.Excess of produced coals should be kept in the stockyards of the collieries. The longer the duration time for these coals, the greater possibility for spontaneous combustion to take place. Spontaneously burnt coals result in economical and environmental problems. Therefore, taking the necessary precautions before an outburst of the spontaneous combustion phenomenon is too important in terms of its severe results. In this study, a stockpile having industrial dimensions was formed in coal stockyard. The effective parameters on the stockpiles of coal such as temperature and humidity of the weather, time, and atmospheric pressure values were measured. The interior temperature variations of these stockpiles caused by the atmospheric conditions were also measured. The interior temperature distribution maps of the stockpile together with maximum and minimum temperature values were expressed visually and numerically by the assistance of obtained data.
