Browsing by Author "Karmakar, N.C."

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Acoustic pollution is a significant mine environmental system problem. It can be defined as a sound without agreeable quality or as unwanted sound. The problem of noise is likely to increase in coming years as mines become larger and more mechanised employing bigger and more powerful machines in greater number. Hindrance in vocal communication in an environment of high noise may cause accidents. Masking of warning signals as in case of roof falls may lead to serious consequences. Also a person becomes irritable and quarrelsome and loses concentration. This results in decreased efficiency and incidents of errors increase. The most serious effects of exposure to high noise levels are deafness, which is initially temporary but with prolonged exposure to high levels, gradually becomes permanent. Hence, the noise of the levels higher than the standards laid down by the Ministry of Environment and Forest must be abated not only to achieve greater percentage of production, but also to restore physical health of workers at work place. This paper focuses on the adverse effects of noise on workers in mining industry.
(Impact of noise on miners - A critical review) Vardhan, H.; Karmakar, N.C.; Rao, Y.V.
2003
An experimental study was carried out to investigate the principal sources of sound from heavy earth-moving machinery, namely a bulldozer and a front-end loader. Major sound sources were the exhaust and air inlet for the engines and the engine cooling fan on the bulldozer. Sound from the exhaust was an important source at nominal one-third-octave midband frequencies from 25 Hz to 250 Hz; sound from the air inlet was a significant contributor in the range of midband frequencies from 25 Hz to 500 Hz. Cooling fan noise for the bulldozer was important in the frequency range from 315 Hz to 3150 Hz. For the front-end loader, the enclosed cab in which the operator sits provided good noise reduction at frequencies greater than 400 Hz up to 20 kHz. Examination of the spectrum of the sound produced by these and other heavy earth-moving machines can indicate the need for maintenance efforts to restore noise-control capabilities that were originally installed or which should be installed. © 2005 Institute of Noise Control Engineering.
(Institute of Noise Control Engineering, Experimental study of sources of noise from heavy earth-moving machinery) Vardhan, H.; Karmakar, N.C.; Rao, Y.V.
2005
Assessment of heavy earth-moving machinery noise vis-à-vis routine maintenance
(2006) Vardhan, H.; Karmakar, N.C.; Rao Y.V.
Exposure to noise from various types of equipment/machinery has been identified as a critical health hazard for personnel working in the Indian mining industry. Heavy Earth Moving Machinery (HEMM) used in mines has been identified as a major source of noise, and several earlier investigators have proposed various types of retrofit measures on these machines to reduce noise. The present work was taken up with the objective of evaluating the noise generation characteristics of HEMM as influenced by periodic maintenance. Detailed noise measurements were carried out in a large open pit coal mine located in India. The effect of maintenance on noise production was assessed for ten dumpers and three dozers by measuring the A-weighted one-third-octave band sound pressure levels after the machines had been subjected to maintenance at the end of 300 hours, 500 hours, 750 hours and 1000 hours of use. Measurements were also carried out to assess the effect of maintaining specific HEMM systems noise characteristics at 1000 hours. Assessment of sound pressure levels at each periodic maintenance revealed major sound level reductions with 1000 hours maintenance. The data also identified the major noise generating systems in HEMM as air systems, exhaust systems, cooling systems and fuel systems. © 2006 Institute of Noise Control Engineering.
Assessment of heavy earth-moving machinery noise vis-à-vis routine maintenance
(2006) Vardhan, H.; Karmakar, N.C.; Rao, Y.V.
Exposure to noise from various types of equipment/machinery has been identified as a critical health hazard for personnel working in the Indian mining industry. Heavy Earth Moving Machinery (HEMM) used in mines has been identified as a major source of noise, and several earlier investigators have proposed various types of retrofit measures on these machines to reduce noise. The present work was taken up with the objective of evaluating the noise generation characteristics of HEMM as influenced by periodic maintenance. Detailed noise measurements were carried out in a large open pit coal mine located in India. The effect of maintenance on noise production was assessed for ten dumpers and three dozers by measuring the A-weighted one-third-octave band sound pressure levels after the machines had been subjected to maintenance at the end of 300 hours, 500 hours, 750 hours and 1000 hours of use. Measurements were also carried out to assess the effect of maintaining specific HEMM systems noise characteristics at 1000 hours. Assessment of sound pressure levels at each periodic maintenance revealed major sound level reductions with 1000 hours maintenance. The data also identified the major noise generating systems in HEMM as air systems, exhaust systems, cooling systems and fuel systems. © 2006 Institute of Noise Control Engineering.
Design of haul road lighting system. Part I: Design based on optimal energy considerations
(2006) Karmakar, N.C.; Mangalpady, M.; Rao, Y.V.; Yaragatti, U.R.
Electrical energy consumption is a major cost component of haul road lighting. Haul road lighting depends on many parameters such as type and wattage of sources, mounting height and tilt angle of light fixtures. In this study a computer model has been developed for optimum energy consumption of any haul road lighting system. Using the program, illumination design was studied for a stretch of 800m long haul road. Nine different types of light sources were considered for mounting heights of 12 and 16m. High-pressure sodium vapour (HPSV) lamps of 100W proved to be energy efficient at a 12m height whereas at 16m height, energy consumption was minimum for 150 W HPSV lamps. Thus the developed computer program proved to be successful in evaluating the performance of lighting designs from the point of view of energy consumption.
Design of haul road lighting system. Part II: Design based on optimal cost considerations
(2006) Karmakar, N.C.; Mangalpady, M.; Rao, Y.V.; Yaragatti, U.R.
The proper selection of lighting installations is very important for the provision of cost-effective lighting systems without compromising light quality. In this study a computer program was developed to evolve a cost-effective lighting system for haul roads in surface mines. This program is beneficial in assessing the viability of various lighting installations in order to achieve cost-effective solutions. Using the program, illumination design was studied for an 800 m long stretch of haul road. Nine different types of light sources were considered at mounting heights of 12 m and 16 m. The study shows that at a 12 m mounting height, 100 W high-pressure sodium vapour (HPSV) lamps offer the most cost-effective design, followed by 250 W HPSV lamps. In the case of 16 m pole heights the annual lighting cost is minimum for 150 W HPSV lamps, followed by 250 W HPSV lamps. This work also shows that optimum design based on energy consumption need not be the same as design based on optimum cost considerations as cost parameters may vary widely with location.
Design of haul road lighting system. Part III: Application
(2006) Karmakar, N.C.; Aruna, M.; Rao, Y.V.; Yaragatti, Udaykumar R.
The design of haul road illumination systems based on a scientific approach is very important. Improperly planned lighting systems may provide unsatisfactory illumination and may also incur higher costs. This paper describes illumination systems designed for two haul roads using the computer programs developed in earlier stages of this work. System performances and cost are compared with the existing illumination system. Designs based on the developed programs show total potential cost savings of approximately 26% and 48% for the two systems.
Design of haul road lighting system. Part III: Application
(2006) Karmakar, N.C.; Mangalpady, M.; Rao, Y.V.; Yaragatti, U.R.
The design of haul road illumination systems based on a scientific approach is very important. Improperly planned lighting systems may provide unsatisfactory illumination and may also incur higher costs. This paper describes illumination systems designed for two haul roads using the computer programs developed in earlier stages of this work. System performances and cost are compared with the existing illumination system. Designs based on the developed programs show total potential cost savings of approximately 26% and 48% for the two systems.
Designing cost-effective lighting system for surface mine projects
(2006) Mangalpady, M.; Karmakar, N.C.; Rao, Y.V.
The objective of lighting in mines is to provide good illumination, which improves the safe and efficient working environment. The artificial lighting is very much essential for the sustained production, to meet the ever-growing demand of the mineral industry. Haul roads within the pit are one of the critical areas in surface mines where lighting installations are not permanent due to regular movement of faces. Though the initial investment for the lighting is very less compared to total project cost, the annual cost is considerably high against the running cost of the project. The proper selection of lamps, reflectors, mountings etc., for particular type of work is very important for energy efficient lighting system, without compromising with the quality of light. A computer model has been developed to evolve a cost effective lighting system for surface mine projects. This model helps in assessing viability of various light sources, so as to achieve energy effective solutions. Properly designed lighting system can prove to be a very cost effective investment for the mine owner.
Estimating rock properties using sound signal dominant frequencies during diamond core drilling operations
(Chinese Academy of Sciences rockgeotech@whrsm.ac.cn, 2019) Vijaya Kumar, C.V.; Vardhan, H.; Murthy, C.S.N.; Karmakar, N.C.
In many engineering applications such as mining, geotechnical and petroleum industries, drilling operation is widely used. The drilling operation produces sound by-product, which could be helpful for preliminary estimation of the rock properties. Nevertheless, determination of rock properties is very difficult by the conventional methods in terms of high accuracy, and thus it is expensive and time-consuming. In this context, a new technique was developed based on the estimation of rock properties using dominant frequencies from sound pressure level generated during diamond core drilling operations. First, sound pressure level was recorded and sound signals of these sound frequencies were analyzed using fast Fourier transform (FFT). Rock drilling experiments were performed on five different types of rock samples using computer numerical control (CNC) drilling machine BMV 45 T20. Using simple linear regression analysis, mathematical equations were developed for various rock properties, i.e. uniaxial compressive strength, Brazilian tensile strength, density, and dominant frequencies of sound pressure level. The developed models can be utilized at early stage of design to predict rock properties. © 2019 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences
[No abstract available]
(Methodology for evaluation of noise levels emanated from mining machinery) Vardhan, H.; Karmakar, N.C.; Rao, Y.V.
2004
[No abstract available]
(Designing lanterns for the efficient lighting of mine roadways - An experimental approach) Mangalpady, M.; Rao, Y.V.; Karmakar, N.C.
2005
Noise analysis of heavy earth moving machinery deployed in opencast mines and development of suitable maintenance guidelines for its attenuation - Part 2
(2004) Vardhan, H.; Rao Y.V.; Karmakar, N.C.
The noise analysis of heavy earth moving machinery deployed in opencast mines and development of suitable maintenance guidelines for its attenuation were discussed. The impact of periodic maintenance on the noise characteristics of machines was studied. The maintenance schedule for which maximum fluctuation in the noise level occured was analyzed. The noise control of heavy earth moving equipment used in opencast was also elaborated.
Noise analysis of heavy earth moving machinery deployed in opencast mines and development of suitable maintenance guidelines for its attenuation - Part 2
(Multi-Science Publishing Co. Ltd, 2004) Vardhan, H.; Rao, Y.V.; Karmakar, N.C.
The noise analysis of heavy earth moving machinery deployed in opencast mines and development of suitable maintenance guidelines for its attenuation were discussed. The impact of periodic maintenance on the noise characteristics of machines was studied. The maintenance schedule for which maximum fluctuation in the noise level occured was analyzed. The noise control of heavy earth moving equipment used in opencast was also elaborated.
Noise problem and its control for heavy earth moving machinery deployed in opencast mines - A critical review
(2006) Vardhan, H.; Rao Y.V.; Karmakar, N.C.
Worldwide, increasingly stringent regulations are coming into force, limiting the exposure of workers to industrial noise. Industrial noise and its consequences, is thus growing importance to employers, local and central government officials, trade unions, occupational hygienists and physicians and insurers. India is not an exception far this. The mining industry in India is facing serious problem of noise due to increasing demand of minerals for which large capacity machines are being deployed producing high noise levels. The present paper thoroughly reviews the noise problem and its control for heavy earth moving machinery's deployed in opencast mines both in India and worldwide. The various noise control approaches for heavy earth moving machinery's deployed in opencast mines are also discussed.
Noise problem and its control for heavy earth moving machinery deployed in opencast mines - A critical review
(2006) Vardhan, H.; Rao, Y.V.; Karmakar, N.C.
Worldwide, increasingly stringent regulations are coming into force, limiting the exposure of workers to industrial noise. Industrial noise and its consequences, is thus growing importance to employers, local and central government officials, trade unions, occupational hygienists and physicians and insurers. India is not an exception far this. The mining industry in India is facing serious problem of noise due to increasing demand of minerals for which large capacity machines are being deployed producing high noise levels. The present paper thoroughly reviews the noise problem and its control for heavy earth moving machinery's deployed in opencast mines both in India and worldwide. The various noise control approaches for heavy earth moving machinery's deployed in opencast mines are also discussed.
Worldwide, increasingly stringent regulations are coming into force, limiting the exposure of workers to industrial noise. Industrial noise and its consequences are thus growing in importance to employers, local and central government officials, trade unions, occupational hygienists and physicians and insurers. India is not an exception to this. The mining industry in India is facing serious problems over noise due to increasing demand for minerals for which large capacity machines are being deployed producing high noise levels. To know the status and to control the noise, the S&T Department of the Ministry of Coal, Government of India sponsored a research project in the area of noise pollution and its control for opencast projects. To start with, a detailed literature survey was carried out in the area of noise pollution and its control in the mining industry, embracing equipment like from Heavy Earth Moving Machinery (HEMM), compressors, workshops, pneumatic drills, processing plants etc, to know the quantum of work done in and worldwide. The various aspects studied In this project were the daily noise dose and/or noise exposure level of the operators of various types of heavy earth moving machinery and its assessment, noise characteristics at different operating conditions of the machine, analysis of noise coming out from different parts of the machine, analysis of noise at different distances from the machine for different frequency components and the most important one i.e., impact of periodic maintenance on the noise characteristics of machines and to find out with which maintenance schedule there is maximum fluctuation in the noise level and to evolve a technique for attenuating the noise generated from these machines as well as to reduce the operator's exposure to high noise levels. This paper highlights the results of this research project.
(Multi-Science Publishing Co. Ltd, Noise analysis of heavy earth moving machinery deployed in opencast mines and development of suitable maintenance guidelines for its attenuation - Part 3) Vardhan, H.; Rao, Y.V.; Karmakar, N.C.
2004
Worldwide, increasingly stringent regulations are coming into force, limiting the exposure of workers to industrial noise. Industrial noise and its consequences is thus growing in importance to employers, local and central government officials, trade unions, occupational hygienists and physicians and insurers. India is not an exception for this. The mining industry in India is facing serious problem of noise due to increasing demand for minerals for which large capacity machines are being deployed producing high noise levels. To know the status and to control the noise, the S&T Department of the Ministry of Coal, Government of India sponsored a research project in the area of noise pollution and its control for opencast projects. To start with, a detailed literature survey was carried out in the area of noise pollution and its control in the mining industry, embracing equipment like from Heavy Earth Moving Machinery (HEMM), compressors, workshops, pneumatic drills, processing plants etc., to know the quantum of work done in India and worldwide. The various aspects studied in this project were the daily noise dose and/or noise exposure level of the operators of various types of heavy earth moving machinery and its assessment, noise characteristics at different operating conditions of the machine, analysis of noise coming out from different parts of the machine, analysis of noise at different distances from the machine for different frequency components and the most important one i e, impact of periodic maintenance on the noise characteristics of machines and to find out with which maintenance schedule there is maximum fluctuation in the noise level and to evolve a technique for attenuating the noise generated from these machines as well as to reduce the operator's exposure to high noise levels. This paper highlights the results of this research project.
(Multi-Science Publishing Co. Ltd, Noise analysis of heavy earth moving machinery deployed in opencast mines and development of suitable maintenance guidelines for its attenuation - Part 1) Vardhan, H.; Rao, Y.V.; Karmakar, N.C.
2004