Comparison Of Practical Results Research Articles

The measurement and practical effectiveness of noise attenuation kits for mobile equipment

The control of noise emissions from mobile equipment in quarry and mine sites plays a critical role in mitigating noise impacts to meet project noise limits while maximizing production capacity. To meet stringent noise limits, sites are commonly required to reduce noise emissions from mobile plants. This is typically achieved through the implementation of retrofit noise attenuation kits. This paper explores a number of case studies in which noise attenuation kits are installed, comparing sound power level measurement methodologies and assessing the effectiveness of attenuation kits through the analysis of resulting reductions in sound power level. Case studies involve the application of sound power tests in accordance with ISO test standards, and the comparison of practical results against theoretical predictions to assess the true effectiveness of attenuation kits.

Experimental Evaluation of Airlift Performance for Vertical Pumping of Water in Underground Mines

This paper presents experimental studies on the optimization of air–water flow in an airlift pump. Airlift pumps use compressed gas to verticall transport liquids and slurries. Due to the lack of theoretical equations for designing and predicting flow regimes, experimental investigations must be carried out to find the best condition to operate an airlift pump at high efficiency. We used a new air injection system and different submergence ratios to evaluate the output of a simple pump for vertical displacement of water in an underground mine. The tests were carried out in a new device with 5.64 m height and 10.2 cm circular riser pipe. Three air-jacket pipes, at different gas flows in the range of 0.002–0.09 m3/s were investigated with eight submergence ratios. It was found that with the same air flow rate, the most efficient flow of water was achieved when an air jacket with 3 mm diameter holes was used with a submergence ratio between 0.6 and 0.75. In addition, a comparison of practical results with two theoretical models proposed by other investigators showed that neither was able to accurately predict airlift performance in air–water flow mode.

The Institution of Mechanical Engineers

The Institution of Mechanical Engineers