Conventional and numerical models of blasting gas behaviour in auxiliary ventilation of mining headings

Abstract A study has been carried out in a coal heading, excavated by drilling and blasting in a deep underground mine located in Northern Spain (Hullera Vasco Leonesa S.A.), by measurements of blasting gases, CO and NO 2 , in three cross-sections of the heading located at 20, 30 and 40 m from the heading face. Mathematical models of gas dilution, according to the dilution time after blasting, have been developed. These models show the differences between the obtained values by application of these experimental models and the values of other mathematical model in common use. The mentioned differences indicate the need to obtain in each underground work its own dilution models of blasting gases. This need is more important when the mass of explosives, the cross sectional area of the heading and the conditions of the auxiliary ventilation keep away from the ones used in order to obtain the mathematical model in common use. 4D models have been developed by Computational Fluid Dynamics (CFD) through software Ansys CFX 12.0. The CFD model results have been validated and compared to experimental models obtained in the measurement programmes. From these CFD models other dilution behaviour mathematical models of blasting gases can be developed for other cross sectional areas, other mass of explosives and other ventilation parameters. The experimental mathematical models and CFD models obtained allow us to analyse how the blasting gases behave and therefore to know in which conditions it is safe for the workers to return to a blasted area.

[1]  J. Toraño Álvarez,et al.  A computer program for calculating ventilation in tunnelling works based on an explicit method , 2002 .

[2]  J. Toraño,et al.  A study of hydrocyclone classification of coal fines by CFD modeling and laboratory tests , 2011 .

[3]  Euler De Souza,et al.  On the prediction of blasting toxic fumes and dilution ventilation , 1991 .

[4]  Karim Van Maele,et al.  Application of RANS and LES field simulations to predict the critical ventilation velocity in longitudinally ventilated horizontal tunnels , 2008 .

[5]  Mustafa Önder,et al.  Statistical model for the volume rate reaching the end of ventilation duct , 2008 .

[6]  C. Méndez,et al.  Numerical and experimental analysis of different ventilation systems in deep mines , 2006 .

[7]  Da-Wen Sun,et al.  Applications of computational fluid dynamics (CFD) in the modelling and design of ventilation systems in the agricultural industry: a review. , 2007, Bioresource technology.

[8]  Javier Toraño,et al.  Application of outburst risk indices in the underground coal mines by sublevel caving , 2012 .

[9]  Jamey Jacob,et al.  New approaches to mine-face ventilation , 2003 .

[10]  D N Sørensen,et al.  Quality control of computational fluid dynamics in indoor environments. , 2003, Indoor Air: International Journal of Indoor Environment and Health.

[11]  Jürgen F. Brune,et al.  Computational Fluid Dynamics Study On The Ventilation Flow Paths In Longwall Gobs , 1900 .

[12]  J. Toraño,et al.  Computational Fluid Dynamics (CFD) Use InThe Simulation Of The Death End Ventilation InTunnels And Galleries , 2006 .

[13]  Samuel Frimpong,et al.  Assessment of the efficiencies of auxiliary ventilation systems using empirical methods , 2001 .

[14]  S. Torno,et al.  Study of ventilation reversion of airflow in mining roadways and tunnels by CFD and experimental methods , 2010 .

[15]  Javier Toraño,et al.  Auxiliary ventilation in mining roadways driven with roadheaders: Validated CFD modelling of dust behaviour , 2011 .

[16]  Javier Toraño,et al.  Models of methane behaviour in auxiliary ventilation of underground coal mining , 2009 .

[17]  C. Gherghel.  THE INFLUENCE OF VENTILATION MODELING ON PRODUCTION PLANNING , 2010 .

[18]  J. Likar,et al.  Ventilation Design of Enclosed Underground Structures , 2000 .

[19]  Hsin Wei Wu,et al.  Development of an assessment tool to minimize safe after blast re-entry time to improve the mining cycle , 2004 .