Application of Fluid Transients to Hydraulic Mining

Abstract

Hydraulic mining involves the erosion of a material with a high speed water jet. This technique can be applied to coal mining, tunnelling for high speed ground transportation systems and drilling for deep oil wells. A high speed, unsteady jet of water is known to have a much greater potential for hydraulic mining than a steady jet of water. A comprehensive study of mining with unsteady jets would involve three aspects: (1) the hydraulic and mechanical aspects of producing an unsteady jet, (2) the study of the dispersion of the jet, and (3) the response of the material being eroded. This paper deals with the first aspect and studies three different systems for producing unsteady water jets. A computer program was written to calculate the unsteady jet velocities for each system using the method of characteristics. The unsteady jet velocity was integrated and used in a theoretical model to compare the effectiveness of the three different systems. The effect of varying certain design and operating parameters of the system was also studied. Factors affecting the choice of the appropriate system are discussed.