Energy efficient technologies for the mining industry

Abstract

The cavitation generator of fluid pressure oscillations is a promising device for productivity and efficiency improvement in the mining industry (hereinafter referred to as the generator). Due to the periodic growth, separation and collapse of cavitation cavities into generator volume, shock pressure oscillations are realized with a frequency range from 1 to 20 kHz. Oscillatory pressure peak values are up by 4 times higher than the steady-state pressure at the generator inlet. The destroyed rock takes on a fatigue character under repeated alternating effects of force impulses. Due to the development of a network of microcracks in the rock, the discontinuity of the rock mass occurs at stresses lower than the rock ultimate strength. This leads to an increase in the rate of penetration, high-quality disintegration of well productive zones and an increase in their production rate, as well as to effective loosening and degassing of outburst-prone coal seams. Purpose. To conduct a systematic analysis of the use of a cavitation generator in the mining industry and evaluate its effectiveness. To develop a simplified method for calculating the maximum values of the range of fluid pressure oscillations by the generator. Methodology. The techniques are based on the study of recent research and publications on the use of the generator as a means of impulse action, and on the processing of on its dynamic parameters experimental data. Findings. The results are given in the form of the main parameters that determine the efficiency of technological processes with hydro pulse exposure. The calculation dependences of values are presented of the cavitation parameter for which of the maximum levels of the fluid oscillation are implemented on the injection pressure and those of the maximum values of the range of fluctuations on the cavitation parameter. Originality. It has been established that the use of the generator as a means of impulse action intensifies the mining industrys technological processes and leads to a significant reduction in specific energy consumption. A new simplified method for calculating the maximum level of the oscillation range has been developed, which makes it possible to determine the rational operation modes of the generator. Practical value. At the stage of designing new equipment or upgrading existing equipment, this simplified method allows determining the effective mode of operation of the generator by engineering methods to reduce the specific energy consumption of the technological process.

Sonic Drilling with a Cavitation Hydraulic Vibrator: Theoretical Computation of the Energy Performance and Rate of Penetration

“…Using the accumulated experience in the development and industrial testing of cavitation technologies in various industries [27], including mining [28], at the Institute of Technical Mechanics of the National Academy of Sciences of Ukraine (ITM NASU) created a new direction in the development of submersible impact machines. The key element in such devices was a cavitation generator (hereinafter referred to as the generator is a Venturi tube of special geometry), which implements shock vibrations in the acoustic frequency range and above [29].…”

“…For the first case (28), Figure 11 shows that the energy intensity of destruction of hard rocks A V was determined for hard rocks in accordance with Ref. [44], and the power supplied to the bottom N was equated to the peak hydraulic power in the cross-section of the drilling tool N hi .…”