R & D work on mine fire and fire monitoring on mines

R & D WORK ON MINE FIRES AND FIRE MONITORING IN FIELD

Submitted by Partha Sarathi Panda

109MN0121

What is mine fire?A coal seam fire or mine fire is the underground smouldering of a coal deposit, often in a coal mine.

Such fires have economic, social and ecological impacts.

To start a fire , the following conditions are essential:- Presence of combustible material.- Presence of source of ignition of sufficient intensity- Presence of oxygen- Contact of combustible material and source of ignition for some time.

Mine fire in underground mine of China

R & D works and projects on ‘MINE FIRES’

For detection of mine fires. For simulation of underground mine fires. To combat mine fires.Many research works have been done and presently being done by different organizations all over the world.Some of them are - CMRI

- CMPDI - NIOSH , and many more.

OBJECTIVE OF THE RESEARCH WORKS ON MINE FIRES

Mine fires represent one of the greatest threats to those working in the underground mine environment.

The intent of the research is to provide the mine operator and miners with an understanding of the conditions that could lead to a fire, the capability to detect unusual heating or fire conditions and the technology to suppress and extinguish a fire to ensure the best outcome possible

Research and development work for detection of mine fires

(1) Detecting coal fires using remote sensing techniques…

J. Zhang , W. Wagner , A. Prakash ,H. Mehl & S. Voigt The surface features and by products of coal fires include

pyro-metamorphic rocks, fumarolic minerals, burnt pits and trench, subsidence and cracks, and surface thermal anomalies.

These features can be detected from visible, near infrared, short-wave infrared, radar and thermal infrared remote sensing images.

The ability to detect these features is limited by the spectral, spatial and temporal resolution of the remote sensing data.

The advances of new remote sensing systems will enhance the capability to detect coal fire related features.

DETECTION OF COAL FIRES USING REMOTE SENSING TECHNIQUES

(2) Detecting unknown coal fires: synergy of automated coal fire risk area delineation and improved thermal anomaly

extractionC. KUENZER, J. ZHANG, J. LI, W.WAGNER, Claudia Kuenzer

This paper presents two complementing algorithms for remote sensing based coal fire research and the results derived thereof. Both are applicable on Landsat, ASTER and MODIS data.

The first algorithm automatically delineates coal fire risk areas from multispectral satellite data.

The second automatically extracts local coal fire related thermal anomalies from thermal data.

This is the first time in coal fire research that unknown coal fires were detected in satellite remote sensing data exclusively and were validated later subsequently during in situ field checks.

IMPROVED THERMAL ANOMALY FOR DETECTING COAL FIRE AREAS

(3) Multi-sensor data fusion for the detection of underground coal fires

X.M. Zhang, C.J.S. Cassells & J.L. van Genderen They presented a remote-sensing based multi-sensor data-

fusion methodology for detecting the underground fires. For the methodology they took data and information from

- Aerial photography- Airborne thermal infrared data- High resolution optical satellite data- Satellite thermal infrared data- Satellite based microwave data- Multi-sensor data fusion

The methodology is based on fusing a variety of satellite-based image types (optical, thermal, microwave) together with airborne data (optical and thermal infrared) and ancillary data sources such as geological and topographic maps.

MULTI-SENSOR DATA IMAGE OF COAL MINE FIRES

(4) Delineation of coalfield surface fires by thresholding Landsat TM-7 day-time image dataAshwani Raju , Ravi P. Gupta & Anupma Prakash

The heat energy emitted from surface fires affects the signal recorded by sensors operating in the shortwave infrared regions of the electromagnetic spectrum.

The Landsat TM/ETM+ band-7 is sensitive to solar reflected radiation as well as emitted radiation from a target.

In this study, no corrections for atmosphere have been implemented for the simple reason that in the SWIR part of EM spectrum, the effect of atmosphere is quite minimal.

LANDSAT TM-7 DAY-TIME IMAGE DATA TO DISTINGUISH COAL FIRE AND NON COAL FIRE PIXELS…

Research and development work for simulation of mine fires

(1) Spontaneous Combustion and Simulation of Mine Fires and Their Effects on Mine Ventilation Systems

A D S Gillies, H W Wu and D Humphreys

The structure of a comprehensive research project into mine fires study applying the ‘Ventgraph’ mine fire simulation software, preplanning of escape scenarios and general interaction with rescue responses.

It focuses on the simulation of spontaneous combustion sourced heatings that develop into open fires.

Further, it examines ventilation behaviour effects of spontaneous combustion initiated pillar fires and examines the difficulties these can be present if a ventilation reversal occurs.

It also briefly examines simulation of use of the inertisation to assist in mine recovery.

The comparison of MFIRE and experiment result of ventilation flow rate of an underground tunnel.

(2) Improvement and upgrade of mine fire simulation program ‘MFIRE’

ZHOU Li-hong , LUO Yi

This research carried out to improve and upgrade the MFIRE 2.20 program to MFIRE 2.30.

The new additions of MFIRE 2.30 including a time dependent fire model, smoke rollback prediction, the incorporation of a moving fire source, and a rewriting of MFIRE in Microsoft Visual C++ were interpreted.

Both MineFire and VentGraph can provide a dynamic representation of the fire’s progress (in real time) and utilizes a colour-graphic visualization of the spread of combustion products, oxygen and temperature throughout the ventilation system, which are the most fundamental features of fire simulation software

To combat mine fires(1) APPLICATION OF CARBON DIOXIDE (CO2) FOR

CONTROLLING SUBSURFACE FIRE AREA

N. K. Mohalik, V. K. Singh, and R. V. K. Singh

This paper presents scientific relevance and selective criteria for use of inert gas for control of subsurface fire.

Infusion of inert gases into sealed off area removes heat from the fire area by cooling and reducing oxygen percentage to cut off combustion process.

The use of carbon dioxide for prevention, control and extinguishing underground fires was started from 1980.

Experiences of the use of carbon dioxide in sealed off area in earlier studies and in present study show that it is an effective method for control of fire in Indian underground coal mines and therefore it is a recommended technology for Indian mines.

(2) Application of three-phase foam to fight an extraordinarily serious coal mine fire

Fubao Zhou , Wanxing Ren , Deming yang , Tiliang Song , Xiang Li and Yuliang Zhang

This paper deals on the application of three phase foam to fight the underground mine fire.

A three-phase foam is composed of mud, nitrogen, and water which can be injected into the fire zone through boreholes on the ground surface.

Following nitrogen infusion into the slurry containing the foam agent, the three-phase foam increases rapidly in volume. It can stack upon itself, which helps fill the mine goaf and cover the coal left in the goaf.

Three-phase foam produced in situ

(3) Recent Developments and Practices toControl Fire in Underground Coal Mines

The paper addresses all those control techniques in detail. Success story of controlling fires in coal mines of different parts of the world are reported.

Some of them are:- Injection of Inert Gases- Nitrogen- Dynamic Balancing of Pressure- Reversal of Underground Mine Ventilation- High Pressure Foam- Inertisation of Goaf in Operating Panels- Water Mist

Dynamic balancing of pressure in a Bord & Pillar working

R & D PROJECTS ON MINE FIRES COMPLETED DURING 2004-08

Highlights of ‘NIOSH’ mine fire research

National Institute for Occupational Safety and Health is conducting a comprehensive program of research addressing metal/non-metal and coal mine fire prevention, detection and suppression. They include the areas of spontaneous combustion, flame cutting and welding, conveyor belt fire suppression and remote control methods for addressing coal mine fires.(i) Spontaneous combustion Most spontaneous combustion fires occur in gob areas that are not

accessible and require remote detection and extinguishing efforts. The hazard is of particular concern in mines

A computer model has been developed from existing computational fluid dynamic (commonly called "CFD") codes to describe the ventilation pathways through the immediate gob. Simulations have been conducted for a variety of bleederless and bleeder ventilation scenarios and also to evaluate the effect of methane emission rate and ventilation on self-heating in longwall gob areas with a bleederless ventilation system.

This work can be used to assist in the design of ventilation systems where spontaneous combustion risk is high.

(ii) Flame cutting and welding

To determine the causes of the fires and injuries caused by flame cutting or welding operations, data from accident investigations were analysed to determine the root cause of flame cutting and welding fires in the coal mining sector.

Existing training methods and procedures were examined and improvements to these methods and procedures were developed and tested in the field. A safety awareness toolbox, Tame the Flame, is planned for release in the near future.

(3) Conveyor belt fire suppression

NIOSH, in partnership with the US Mine Safety and Health Administration (MSHA) , initiated a test program to determine the effectiveness of fire suppression systems on conveyor belt fires in entries with high-velocity airflow.

Full-scale experiments evaluated the effectiveness of dry powder chemical suppression systems, water sprinkler systems and water deluge systems in conveyor belt entries at air velocities of zero, 500ft/ min and 1400ft/min.

(4)Remote methods for addressing coal mine fires The objective of this work is to evaluate, improve or

modify remote fire-fighting technologies, including remotely installed mine seals (ventilation barriers), and lire control and suppression technology.

Experiments have been conducted to evaluate cement-based and rigid-foam-based materials.

This work has resulted in new understandings of the limitations of the technology and development of novel down-hole tools to facilitate accurate placement of mine seal materials.

Preliminary research on nitrogen gas-enhanced foam shows that foam can be stable in the mine opening and can accumulate and flow through mine workings

MINE FIRE MONITORING IN FIELD

(1) Monitoring of underground coal fires using thermal infrared data

S.B.Mansor , A.P Cracknell , B.V.Shilin & V.I.GornyiThe potential utility of thermal infrared and short wavelength infrared data for detecting and mapping sub-surface high temperature sources is analyzed.The short wavelength infrared sensors (band 5 &7) have been used to locate positions of intense burning.The investigation also reveals the potential capability of the AVHRR band 3 to detect sub-surface high temperature sources such as coal fires.

(2) Mine fire indices and their application in monitoring mine fires in u/g coal mines

A.K.Singh , R.V.K. Singh , M.P.Singh an N.K.Shukla

Monitoring of gases is the main tool for determination of fire status. On this basis , different fire indices can be determined for examining the extent of fire and for devising efficient combat methods.

The purpose of this paper is to review the existing successful techniques for monitoring the mine fire gases and describe different fire indices such as Graham’s index , Willet’s ratio , C/H ratio,etc. , for interpretation of status of u/g sealed off fires.

REFERENCES http://

www.tandfonline.com/doi/pdf/10.1080/10106049.2012.710651

http://www.tandfonline.com/doi/pdf/10.1080/01431160310001620812

http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1151&context=coal

http://scienceandtech.cmpdi.co.in/PDF%20Files/Mine%20Fire.pdf

http://www.ismdhanbad.ac.in/depart/mining/images/pdfdoc/project-completed.pdf

http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1135&context=coal

http://stacks.cdc.gov/objectView!getDataStreamContent.action?pid=cdc:9799&dsid=DS1&mimeType=application/pdf

http://link.springer.com

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