A project report submitted to the Faculty of Engineering,
University of the Witwatersrand, Johannesburg, in partial
fulfilment of the requirements for the degree of Master
of Science in Engineering. / The flushing flow rate required to maximise penetration
rate of holes drilled by rotary percussion is dependant
on drilling parameters and chip size. Experimental work
to determine the optimal flushing water flow rate for two
common drilling situations was undertaken. It consisted
of drilling, analysis of chip samples and flow
visualization. A computer modal to predict flow rate was
developed. Its output and the experimental results Were
combined to explain the relationship between penetration
rate and flow rate.
All chips should be fiushed from the gap between the bit
and the end of the hole in the time between hammer blows
(ie. - within the duration of a percussion cycle). As
flow rate increases, flushing improves and therefore
penetration rate increases. Once flushing is adequate
there is no mechanism for further increases in
penetration rate, thus it remains constant and
independent of further increases in flow. / Andrew Chakane 2018
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/26151 |
| Date | January 1997 |
| Creators | Kilfoil, Arthur Mark |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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