Gankevich V., Moskalova T., Lyvak O., Kravets V. Implementation of the rock thermal cyclic weakening in the diamond drill bits with an elastic console
- Details
- Parent Category: Geo-Technical Mechanics, 2018
- Category: Collection of scientific papers «Geotekhnicheskaya Mekhanika» Issue 140
Geoteh. meh. 2018, 140, 23-30
DOI: https://doi.org/10.15407/geotm2018.03.023
IMPLEMENTATION OF THE ROCK THERMAL CYCLIC WEAKENING IN THE DIAMOND DRILL BITS WITH AN ELASTIC CONSOLE
1GankevichV., 1MoskalovaT., 2LyvakO., 2KravetsV.
1National Technical University «Dnipro Polytechnic», 2Ukrainian State University of Chemical Technology
UDC622.236.3
Language: Russian
Abstract.
In the article, it is considered the possibility of using thermal cyclic rock weakening in drilling tools. Results of the theoretical and experimental studies of the process of thermal cycling effect on the rocks and glass models are briefly described. The obtained analytical dependences make it possible to determine average cell size of cellular fracture depending on operating parameters of thermal shock and rock properties. They also help to evaluate effectiveness of thermal methods used for the rock loosing with alternating-sign or fitting them over time to a specific process. It is shown that at drilling during the heating phase, temperature above 600° C can be achieved with the help of appropriate friction heating elements. It is also established that cooling phase of the heated section of the rocks can lead to rock cracking and further mechanical destruction.
The improved design solutions for diamond drill bits with an elastic console reinforced by the heat-resistant friction material are presented. Target of the proposed inventions is to eliminate drawbacks of the known diamond drilling bit design, working process of which is characterized by decreased density of friction coating contact and, consequently, followed by degradation of efficiency of the rock heating under the console. This target can be achieved by arranging a multilayer thermo-bimetallic console along the entire height (in the first proposed design of the thermo-mechanical tool) and console curved over the drilling bit body (in the second proposed design of the thermo-mechanical tool). These designs of the tools are protected by Ukrainian patents.
As a result of the study it is concluded that due to the thermal cycling effect on the rocks and glass, energy intensity of destruction is reduced and honeycomb-type grid of cracks is appeared.
Key words: rock, thermal destruction, drilling, friction, heating, cooling, diamond drilling bit, weakening, friction elements.
References:
1. Kozhevnikov, A., Krisan, V. and Vakhalin, Yu. (2011), Razrusheniye gornykh porod pri rezkom okhlazhdenii [The destruction of rocks with a sharp cooling], ALR Lizunov Press, Dnepropetrovsk, Ukraine.
2. Kozhevnikov, A., Kravets, V., Vakhalin, Yu. and Livak, O., Ukrainian State University of Chemical Technology (2018), Termomekhanichny porodorozruyniyuchy instrument [Thermomechanical tool for rock destruction], State Register of Patents of Ukraine, Kyiv, UA, Pat. № 125672.
3. Gankevich V., Vakhalin Yu. and Livak O. National Technical University Dnipro Polytechnic (2019), Termomekhanichny porodorozruyniyuchy instrument[Thermomechanical tool for rock destruction], State Register of Patents of Ukraine, Kyiv, UA, Pat. № 131521.
4. Ermakov, S., Fedorov, L., Vaschenko, D. and Skryabin, R. (2010),”Experimental studies of the softening of strong rocks during friction heating of the friction elements of the thermomechanical crown”, Mining informational and analytical bulletin, no. 7, pp. 44-49.
About the authors:
Gankevich Valentin Feodosevich, Candidate of Technical Sciences (Ph.D), Associate Professor, Department of Mining Machines, National Technical University «Dnepr Polytechnic», Dnepr, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.
Moskalyova Тatiana Vitalyevna, Candidate of Technical Sciences (Ph.D), Associate Professor, Department of Mining Machines, National Technical University «Dnepro Polytechnic», Dnepr, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.
Livak Oksana Viiktorovna, M.S (Tech.), Department of Applied Mechanics, Ukrainian State University of Chemical Technology, Dnepr, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.
Kravets Vasili Ivanovich,Candidate of Technical Sciences (Ph.D), Associate Professor, Department of Applied Mechanics, Ukrainian State University of Chemical Technology, Dnepr, Ukraine, kravets This email address is being protected from spambots. You need JavaScript enabled to view it.