Application of efficient noise control strategy to a vibratory-rotary drilling machine

Abstract

We have applied an efficient noise control strategy to a vibratory-rotary drilling machine, which is capable of geothermal hole drilling, water well drilling, etc. In construction works, lowering of noise is a highly required, particularly in urban areas. The drilling machine of this type is powered by a diesel engine and features a drilling system with a high frequency vibration. A-weighted sound power level of the original model reaches up to 111-116 dB. We have set our reduction target down to about 10 dB. In order to achieve this target noise level efficiently and quickly, we employed following techniques: (i) Noise sources identification and characterization by an acoustic imaging camera with microphone allay (ii) Prediction of countermeasure effectiveness through ray-acoustics simulation method (iii) Repeated testing and assessment With this strategy, appropriate measures were designed and were applied to major noise sources. The lower noise target was safely achieved easily and quickly in this case.