Pulsed liquid jet for rock breaking

Cleary, Edward Thomas (2008) Pulsed liquid jet for rock breaking. [USQ Project]


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[Absent]: Rock fracture using continuous, high speed water jets is an existing technology used in the mining industry. However, it appears that a number of potential benefits can be derived by using pulsed liquid jet technique instead. Reductions in energy and water consumption should be possible because of improvements in efficiency associated with the pulsed water jet technique. However before a pulsed jet technique can be optimised and implemented in a practical system that yields the anticipated performance
improvements relative to the continuous jet system, a thorough understanding of the physical processes involved needs to be obtained.

This project endeavoured to gain a better understanding of pulsed jet technology by modifying the USQ gas gun to include a water reservoir downstream of the barrel which
was used to generate a single, high speed water jet for analysis. A piston with a mass of approximately 55 grams was arranged to impact on the reservoir at different speeds up to 300 m/s. Pressures above 300 MPa were generated in the water reservoir when the piston was decelerated, and these pressures were sufficient to generate a single pulsed
water jet at speeds over 1000 m/s.

High speed photography was used to visualise the establishment of the high speed water jet and analyse the characteristics of the pulse. The pulse impacted on a strike plate which was attached to a vertical brass tube that extended to the floor. The brass tube was instrumented with strain gauges to characterise the high speed water jet. A pressure transducer was used at low pressures to determine the magnitude of the pressure pulse in the water reservoir. This data was then correlated with data recovered from the brass tube to establish a relationship between the two.

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Item Type: USQ Project
Refereed: No
Item Status: Live Archive
Faculty/School / Institute/Centre: Historic - Faculty of Engineering and Surveying - Department of Mechanical and Mechatronic Engineering (Up to 30 Jun 2013)
Date Deposited: 04 Aug 2009 02:46
Last Modified: 02 Jul 2013 23:21
Uncontrolled Keywords: mine; mining; rock; rock breaking; rock fracture; high speed water jet; pulsed liquid jet
Fields of Research (2008): 09 Engineering > 0913 Mechanical Engineering > 091399 Mechanical Engineering not elsewhere classified
09 Engineering > 0914 Resources Engineering and Extractive Metallurgy > 091405 Mining Engineering
Fields of Research (2020): 40 ENGINEERING > 4017 Mechanical engineering > 401799 Mechanical engineering not elsewhere classified
40 ENGINEERING > 4019 Resources engineering and extractive metallurgy > 401905 Mining engineering
URI: https://sear.unisq.edu.au/id/eprint/5520

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