Containing sound from the screw

A new pvc curtain has been fitted at the outlet to damp the sound from the splashing of the screw. At certain river levels and outputs from the screw a sound has been heard which neighbours tell us can be a problem. Other micro hydro plants have found the pvc curtain to be effective in controlling the sound. Initially we tried altering the setting points which control the speed of the screw. This did have the desired effect at low flows but the sound could still be heard at higher flows so we have taken the next step of installing the acoustic curtain.