High levels of impact noise were generated by coal falling into a delivery chute on an industrial site. Expensive noise barriers had been considered, but these would have made access difficult and would have reduced the noise by only around 5dB. Our alternative solution was to design highly damped chute modifications to reduce the noise at source.
These low-cost modifications were retro-fitted with very little downtime and not only reduced the impact noise by 20dB(A), but they also substantially reduced the dust generated (solving another problem in the area) and cut chute wear to reduce the maintenance requirements.
This engineering approach is very effective on all kinds of chutes and hoppers where there is impact noise from a wide variety of objects that include rocks and stones, scrap metal and even high hygiene products such as sweets, tablets and vegetables.