Mining Contract: Method for Improving Ventilation & Gas Monitoring with an Advanced Fiber Optic Based Mine-Wide Monitoring System
OMSHR has previously developed atmospheric monitoring systems in order to minimize the risk of underground mine fires and explosions. However, the need to improve the accuracy, quantity, and timeliness of methane and temperature measurements taken throughout the mine, the hours devoted to sensor calibration and system maintenance, and the utility of these systems to be used in the most active areas of a mine, remote workings, and bleeder entries are gap areas that remain. Also, the system has to be designed to be functional following a large-scale catastrophic event.
Contract Status & Impact
This contract is ongoing.
The objective of this project is to develop and test a prototype mine-wide distributed monitoring system, based on laser energy distributed through a fiber optic network that will continuously monitor and record the atmospheric concentration of methane and the ambient temperature. This information will provide an indication of potential or actual explosion or fire conditions in underground coal mines. The delivered system design shall include specifications for necessary hardware components, instructions for assembly/installation of hardware components, control and recording software, and hardware and software operations manual(s).
RSL Fiber Systems, LLC, was contracted to develop an advanced fiber-optic-based mine-wide methane and temperature monitoring system. This system does not require any underground electrical power and therefore can remain operational in the event of an underground power outage. It provides a wide dynamic methane gas measurement range with sensitivity as low as 150 parts per million and the ability to measure up to 100% methane in the environment. Additionally, it has been shown to be immune to water and any cross-interfering gases likely to be present. It can potentially be expanded to monitor other gases, smoke particles, diesel particulate matter, and possibly coal dusts.
The contractor has designed and assembled a prototype fiber optic-based, distributed sensor system that can reliably produce an alert signal when, at any sensor location, methane concentrations equal 1%; and reliably produce an alarm signal when, at any sensor location, methane concentrations equal 1.5%. The prototype system is also capable of detecting ambient temperature and rate of temperature increase, and provides alert and alarm signals when values exceed limits established via control software. The system is designed and built in a manner that meets Mine Safety and Health Administration (MSHA) approval requirements for intrinsic safety under 30 CFR Part 18.68. A prototype system, four methane sensors, and 1,000 feet of temperature sensing have been installed in an active underground coal mine for extended system testing and evaluation.