A Simple Method for Measuring Basic Parameters of the Coal-Methane System under Mining Conditions
N. Skoczylas, M. Wierzbicki, M. Kudasik
The Strata Mechanics Research Institute of the Polish Academy of Sciences, Cracow, 30-059 Poland
Keywords: Sorption device, coalbed methane content, desorbable methane content, hard coal mining
Abstract
The study is devoted to the methane hazard in hard coal mining. This hazard occurs in almost every coalfield in the world. Ensuring maximum work safety under methane hazard conditions is based, among other things, on reliable, fast and frequent determinations of methane content in a coal seam. The existing methods are time-consuming, and determinations must be performed in laboratories. Indirect methods such as desorbometric methods are burdened with high measurement uncertainties. The study presents a model of methane release from granular coal samples and a device (AMER) developed for measuring methane content in a coal seam under in situ conditions. Measurements are performed in a fully automatic way and preliminary results, based on the approximation of the Crank model, are available within several dozen minutes from the beginning of the measurement. Also, the use of the unipore diffusion equation and a proper software of the device allowed to determine the values of the effective diffusion coefficient. Results of measurements performed with the AMER desorbometer are highly consistent with the results of the measurements performed in the laboratory using a traditional method.
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