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Item Assessment of noise and effect of thrust on penetration rate in percussive drilling(2011) Kivade, S.B.; Murthy, C.S.N.; Vardhan, H.Rock drills are a major source of noise in the mining industry, with levels reaching as high as 115 dbA at the operator's ear. Noise of this amplitude has long been recognized as a serious health hazard. The two major noise sources in pneumatic rock drills are exhaust air and impact of the piston against the drill rod shank. The exhausted compressed air produces noise because it is released at a relatively high pressure and in bursts or pulses. While the impact of the piston against the shank causes vibrations in the drill rod and in different parts of the drill body which then radiate noise. Mufflers can reduce the noise to the order of 105 dbA, at which level the drill rod vibrations become the dominant noise source. The rock types selected for the present study are basalt, gabro granite, pink granite and lime stone. The range of applied thrust varies between 10 kg to 100 kg. All the holes were drilled for a fixed time of one minute and penetration rates were obtained. It was observed that very low thrust results in low penetration rates but on the other hand, even very high thrusts do not produce high penetration rates at high operating air pressures. Optimum thrusts were obtained for each rock type experimentally. This paper deals in detail effect of applied thrust on the penetration rate and sound level of a conventional percussive drill.Item Performance and emission characteristics of double cylinder CI engine operated with cardanol bio fuel blends(2012) Mallikappa, D.N.; Reddy, R.P.; Murthy, C.S.N.India imports more than seventy percent of the oil it uses and is looking for alternative fuel to reduce its dependence on imports. In India, bio fuels derived from non-edible oils is considered as a renewable alternative to the fossil diesel. The cost of the biodiesel is higher than diesel and hence in this work, cardanol was used as an alternative renewable fuel for the diesel engine. The engine tests were conducted on a double cylinder, direct injection, compression ignition engine. From the engine tests, it is observed that the brake power increases (by 70% approximately) as load increases. Brake specific energy conversion decreases (by 25-30% approximately) with increase in brake power. Brake thermal efficiency increases with higher brake power and emission levels (HC, CO, NOX) were nominal up to 20% blends. © 2011 Elsevier Ltd.Item The use of Dimensional Analysis and Optimization of Pneumatic Drilling Operations and Operating Parameters(Springer India sanjiv.goswami@springer.co.in, 2012) Kivade, S.B.; Murthy, C.S.N.; Vardhan, H.Dimensional analysis was used to demonstrate the significance of these important parameters, grouped together in dimensionless numbers which will then allow for optimum use of limited laboratory data to produce better results. It allows for reduction of total effort in designing laboratory experiments, reducing total load and cost, permitting variation of the important dimensional groups rather than individual drilling operating parameters, hence a more efficient design of experiments can be realized. Drilling operations are very expensive endeavors and efforts are continuous by engineers and researchers to achieve the optimum penetration rate. To enhance bit life and penetration rate, optimization of bit design and drilling operations must be realized. To measure the penetration rate of the pneumatic drill, a fabricated pneumatic drill set up available was used. Laboratory tests were carried out to obtain the physical and mechanical properties of the rock samples. Penetration rate has been derived by means of regression statistics method. In order to overcome this drawback, dimensional analysis was used to derive relevant dimensional groups leading to the development of empirical equation of penetration rate. © 2012, The Institution of Engineers (India).Item Reservoir formation damage during various phases of oil and gas recovery- an overview(2012) Puthalath, P.; Murthy, C.S.N.; Surendranathan, A.O.When a reservoir of oil or gas is discovered under the ground, and reservoir engineers and drilling engineers are employed to tap that reservoir, often, they inadvertently damage it. Formation damage is an undesirable operational and economic problem that can occur during the various phases of oil and gas recovery from subsurface reservoirs including production, drilling, stimulation techniques and work over operations. The formation of a reservoir can be damaged by unforeseen rock, fluid, particle interactions etc and alterations caused by reservoir fluid, flow, and stress conditions. For example, the chemicals that the engineers have injected into the reservoir, the drilling mud used in drilling, or even by stress from the drill bit itself may cause formation damage. Control and remediation of formation damage are among the most important issues to be resolved for efficient exploitation of petroleum reservoirs and cost management. Formation damage seems to be inevitable and whether formation damage can be prevented, removed economically, or must be accepted as the price for drilling and producing a well will depend upon many factors. In this paper a general characteristics of formation damage during various stages of oil exploration are discussed. © 2012 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item An economic analysis of environmental pollution and health - a case study of Bellary-Hospet sector(2012) Thimmaiah, S.A.; Ravi, D.R.; Rao, Y.V.; Murthy, C.S.N.The Earth's natural ecosystem is the basis for our life-supporting system and provides marketable goods to human and other living organisms. The natural environment has always been exploited to fulfill human needs. The green revolution and industrial revolution has caused serious threat to sustainable development for both developed and developing countries. The degradation of air, water and land has directly affected the livelihood and human health. The environmental damage increases, as the economic activity increases, in view of the fact that the association between economy and the environment are multiple, complex and important. Mining is one such activity, which significantly results in the degradation of the environment, apart from generating huge economy to the country. Hence, the identification and quantification of socio economic impact of environmental pollution caused due to increased mining activity is necessary in the broader economic analysis. The present study is envisaged with the objective to identify and evaluate the impacts of mining activity on Social, Economical and Environmental Aspects of the area and to measure its economic burden on the affected people. The ambient air quality in the selected stations of study area reveals that, the increase in iron ore production has significantly resulted in the deterioration of air quality. High particulate matter to an extent of 310 ?g/nm3 in case of SPM concentration and 160 ?g/nm3 in case of RSPM. The health data collected from the respondents have revealed, significantly more number of respondents who are suffering from dust allergy, skin allergy in the study area, where there are mines and are working as workers in those mines, contributing for higher health cost incurred through treatment. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.Item Corrosion mitigation of the oil well steels using organic inhibitors-A review(2012) Puthalath, P.; Surendranathan, A.O.; Murthy, C.S.N.Oil well stimulation, usually done with hot solutions of hydrochloric acid, may induce severe corrosion attack on production tubing, downhole tools and casing. Inorganic, organic and combinations of acids along with surfactants are used in a variety of well stimulation treatments. To reduce the aggressive attack of the acid on tubing and casing materials (N80 steel), inhibitors are added to the acid solution during the acidifying process. The inhibition in oil and gas field is more complicated and requires special eco-friendly inhibitors depending on the area of application such as in refineries, wells, recovery units, pipelines etc. Aggressive gases such as H2S, CO2, and organic acids complicate the problem of inhibition in wells. Various factors have to be considered while dealing with corrosion problems of oil and gas industry. The type of reservoir rocks, the acids used for stimulation, the oil well equipments such as tubings and casings and the operating conditions are some of the important factors that affect the corrosivity. Each and every case has to be considered in its totality before a decision is made on the proper materials. No particular material is the cure for all the evils of corrosion. It is imperative to the field operators, pipeline engineers, designers to have corrosion awareness concerning the oil and gas industries in their day to day activities to compact and mitigate corrosion. This work is an attempt in this direction.Item Performance and emission characteristics studies on stationary diesel engines operated with cardanol biofuel blends(2012) Mallikappa, D.N.; Pratap Reddy, R.P.; Murthy, C.S.N.This work composed with performance and emission studies of three stationary diesel engines operated with 20% cardanol biofuel volumetric blends. A single cylinder diesel engine and VCR engines were used to evaluate theperformance and emission characteristics of cardanol biofuel. An extended experimental study was conducted on a double cylinder CI engine, to evaluate the performance and emission characteristics. The cardanol biofuel volumetric blends between 0-25% and base fuel (Petro diesel) were tested at various loads between 0-full load. From the results, brake thermal efficiency, increased with increase in load. The brake specific energy consumption decreased by 30 to 40% with increase in brake power. The HC emissions were nominal up to B20, and more at B25. The NOx emissions (ppm) increased with increased proportion of blends. The carbon monoxide emissions increased with higher blends and decreased slightly at higher loads. From this investigation, it is observed that up to 20% blends of cardanol biofuels may be used in CI engines without any modifications.Item Prediction of penetration rate and sound level produced during percussive drilling using regression and artificial neural network(2012) Kivade, S.B.; Murthy, C.S.N.; Vardhan, H.The main objective of this investigation is to develop a general prediction model and to study the effect of predictor variables such as uniaxial compressive strength, air pressure and thrust on penetration rate and sound level produced during percussive drilling of rocks. The experiment was carried out using three levels Box-Behnken design with full replication in 15 trials. Modeling was done using artificial neural network (ANN) and multipleregression analysis (MRA). These techniques can be utilized for the prediction of process parameters. Comparison of artificial neural network and multiple linear regression models was made and found that error rate was smaller in ANN than that predicted by MRA in terms of sound level and penetration rate. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.Item Laboratory Investigations on Percussive Drilling(Springer India sanjiv.goswami@springer.co.in, 2013) Kivade, S.B.; Murthy, C.S.N.; Vardhan, H.The laboratory investigation was carried out on ten rock samples using pneumatic drill with drill bits of different diameters. In general, the process of drilling always produces sound. Sound is generated from the bit-rock interface regardless of the material of the bit used in drilling. The predicted sound level and penetration rate are a product of the drill power and the physical properties of the rocks penetrated. Rock samples were collected from the field and physical properties of the rocks were determined in the laboratory. The sound level and penetration rates were correlated with the rock properties. The compressive strength and abrasivity exhibit strong correlations with the sound level and penetration rate. It was concluded that, among the rock properties included in this study, the compressive strength and abrasivity values are the dominant ones affecting the penetration rate and sound level of percussive drills. Though ten rock samples have been covered in this study, detailed analysis of only one of them is presented. © 2013, The Institution of Engineers (India).Item Influence of index angle on specific energy in rock indentation test(CAFET INNOVA Technical Society 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2015) Kalyan, B.; Murthy, C.S.N.; Choudhary, R.P.In the present work, static indentation tests were carried out in six types of rocks namely pink marble, limestone, basalt, steel gray granite, moon white granite and black galaxy granite using commercial drill bits of 35mm, 38mm, 45mm, 48mm diameters, aimed to know the influence of index (rotation)angle on specific energy. From the experimental data, Force-Penetration (F-P) curves were plotted and Specific energy (energy necessary to excavate a unit volume of rock) values were calculated from F-P curves for each bit rock combinations. The specific energies for the rocks (pink marble, limestone) at 30° index angle were found to be much less than the specific energies at other index angles. Similarly the specific energies for the rocks (basalt, steel gray granite, moon white granite and black galaxy granite) at 20° index angle were found to be much less than the specific energies at other index angles. © 2015 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.