Santosh Ray - Academia.edu (original) (raw)

Papers by Santosh Ray

Mining, Metallurgy & Exploration , 2022

Coal is a low-cost and high-calorific-value fuel. The coal mining industry worldwide has been suf... more Coal is a low-cost and high-calorific-value fuel. The coal mining industry worldwide has been suffering from severe accidents due to coal dust explosion hazards since its inception. Statistically, it was observed that 12,489 fatalities had occurred in 104 reported mining accidents from coal dust explosions during 1900–2020. There are numerous methods for detection, prevention, and control of coal dust explosions in mines. The underground mining environment is unpredictable and has an array of variables. These undulating factors make it difficult to prevent or control the coal dust explosion hazard. However, coal mining is done aggressively throughout the world, especially in developing countries as coal is a major source of thermal energy used in power plants contributing to about 38% (IEA, (2019), World Energy Outlook, IEA, Paris https:// www.iea. org/ repor ts/ world- energy- outlo ok- 2019.) of world electricity. Worldwide, coal dust explosibility studies are carried out in experimental mines, laboratories, and simulations. The complexity, lack of proper infrastructure, and unavailability of laboratory equipment sometimes make it difficult to study coal dust explosibility. The authors have discussed in detail and proposed that the CFD modelling can be a viable option for studying and evaluating coal dust explosibility.

International Journal of Mining Science and Technology

Mine disasters occur predominantly due to methane or coal dust explosion or a combination of both... more Mine disasters occur predominantly due to methane or coal dust explosion or a combination of both. Among the top ten worst coal mine disasters in India, nine are due to coal dust explosion. The current paper describes a general overview of the parameters causing dispersion leading to coal dust explosion, and computational fluid dynamics (CFD) simulation study to observe the effects of particle size on dispersion in Indian coal mines. Turbulent kinetic energy (TKE) and velocity vector path of dust-air mixture and dust-free air were simulated to understand their effects on coal dust dispersion. The TKE contours and velocity vector paths for dust-free air were uniform and symmetrical due to resistance-free path available. The TKE contours and velocity vector paths for dust-air mixture shows the asymmetrical distribution of contours, due to entrainment of air with dust particles. Vortices were observed in velocity vector paths which gradually diminish on increment of time sequence. These vortices are dead centres where velocity and coal dust particles concentration are both zero.

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects

Thermal power units are a major source of power generation in India. Belt conveyor is the leading... more Thermal power units are a major source of power generation in India. Belt conveyor is the leading transportation system in a thermal power plant. Belt conveyor fire in a thermal power plant breaks ...

Journal of The Institution of Engineers (India): Series D

Spontaneous combustion/fire and explosions occurring in the goaf area due to depillaring of thick... more Spontaneous combustion/fire and explosions occurring in the goaf area due to depillaring of thick coal seam (5-8 m) experiences significant loss to the mining industry. This ultimately causes destruction of natural resources and fatal accidents in India. Thus, it is threatening the safety of underground coal mines. This paper includes various laboratory studies to determine the cause of spontaneous combustion/fire during depillaring of panels in thick coal seams. The laboratory investigation comprises of proximate analysis, critical oxidation temperature study, differential scanning calorimetric analysis, fire ladder study, and goaf ignition temperature. The field investigation comprises of hygrometric survey to determine moisture loss and ventilation survey of the working seam to reveal that the goaf of the working panel is highly prone to spontaneous combustion/fire. The results of the above studies will help to develop suitable technique, i.e., partial stowing in goaf areas with the application of water mist spraying to prevent spontaneous combustion/fire during depillaring of thick coal seam. The above studies were carried out during depillaring panels (B2A and B2B) of a thick seam (5.4 m) at Khottadih Colliery, M/s Eastern Coalfields Limited of Raniganj coalfield of India.

International Journal of Coal Geology, 2014

Spontaneous combustion is an inherent problem to the coal mining industry. The paper describes an... more Spontaneous combustion is an inherent problem to the coal mining industry. The paper describes an electro-chemical method called wet oxidation potential technique for determining the susceptibility of coal to spontaneous combustion. Altogether 78 coal samples collected from thirteen mining companies spreading over most of the Indian Coalfields have been used for this experimental investigation and 936 experiments have been carried out by varying different experimental conditions to standardize wet oxidation potential method for wider application. The results of wet oxidation potential (WOP) method have been correlated with the intrinsic properties of coal by carrying out proximate, ultimate and petrographic analyses of the coal samples. Experimental results are first analyzed with principal components analysis and then by multiple regression analysis. Results obtained from this method have been compared with one of the widely used method, i.e. crossing point temperature (CPT) in India. The experimental investigation clearly indicates that WOP method with 0.2 N KMnO4 in 1 N KOH solution at 45 °C (susceptibility index PD12) should be used for finding out the susceptibility of coal to spontaneous combustion. PD12 results are well corroborated with CPT results.

Transactions of The Institution of Mining and Metallurgy Section A-mining Technology, 2005

Abstract Outbreak of open fire in coal mines is one of the major causes of disaster involving los... more Abstract Outbreak of open fire in coal mines is one of the major causes of disaster involving loss of life, hindrance in coal production and loss of machinery involved in coal winning operations. Until recently, no substantive work has been carried out in India to prevent such untoward incidents. To understand the complex phenomenon of open fires and its preventive techniques, a mine fire model gallery has been designed and constructed at the Central Mining Research Institute, Dhanbad, India. The gallery is equipped with state-of-the-art instrumentation systems to monitor the important fire parameters. Three fire suppression techniques –liquid nitrogen, high-pressure high-stability (HPHS) nitrogen foam, and water mist – were tried in three sets of experiments. This paper addresses the important design features of the gallery, experimental details, and the effects of the application of water mist on open fires. An international literature review regarding the application of water mist technology is also outlined. Experiments showed that water mist has the potential to reduce the intensity of fire, lower the products of combustion (POC) and reduce suspended particulate matter (SPM). Water mist technology is able to control open fires in underground coal mines.

Fire Technology, 2007