Title: Atmospheric monitoring systems in underground coal mines revisited: a study on sensor accuracy and location

Authors: Kemal Baris; Yusuf Aydin

Addresses: Zonguldak Vocational School, Bulent Ecevit University, Kilimli, Turkey ' Labour Inspection Board, Republic of Turkey Ministry of Labour and Social Security, Ankara, Turkey

Abstract: This study covers the long-term measurements and applications done between 15 January 2015 and 21 October 2016 in the Kozlu Colliery, one of the five collieries of Turkish Hardcoal Enterprise (TTK), Zonguldak, Turkey. It intends to address the practical problems encountered with the gas and air velocity sensors used in underground coal mines, and attempts to justify the accuracy of sensors. It also aims at determining the correct locations of the gas and air velocity sensors within cross-section of mine entries. Moreover, air densities were calculated to interpret the positions of individual gases within the mine air. The results showed that the infrared CH4 sensors used in the mine do not accurately measure CH4 concentrations at their current locations. Moreover, they are affected by relative humidity and thus necessitate more frequent calibration at places having high relative humidity. The air velocity sensors used in the mine are completely ineffective in their current state. Changing their locations led to better yet ineffective results. It was found that a correction factor of 1.25 is needed to correct air velocity sensor readings. It was concluded that air velocity, CH4 and CO sensors must be installed to points where air flow is higher, considering the Amagat's law. [Received: October 17, 2017; Accepted: April 4, 2018]

Keywords: atmospheric monitoring systems; AMS; gas sensors; methane; air velocity; underground mining; mine ventilation; sensor accuracy; sensor location.

DOI: 10.1504/IJOGCT.2020.105777

International Journal of Oil, Gas and Coal Technology, 2020 Vol.23 No.3, pp.325 - 350

Received: 17 Oct 2017
Accepted: 26 Apr 2018

Published online: 13 Mar 2020 *

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