The present invention relates to a self-contained unit having a system for recovering polymer overspray from a pallet coating process. The self-contained unit includes a common enclosure having at least four walls, a ceiling and a floor. There is a collection tank located below the floor of the common enclosure and a roof platform is located above the ceiling of the common enclosure. Within the common enclosure is at least one spray booth having a waterfall wall with liquid flowing down a face of the waterfall wall to the collection tank. Mounted on the roof platform is a consolidation tank, hydrocyclone and pressure filter that are all part of the system for removing the polymer from the overspray mixture collected at the collection tank.

A sedimentation device for separating a solid-liquid suspension has a settling tank, a feed well, a feed pipe, an overflow collector and a mixing area. A pump is disposed in the overflow collector and overflow from the overflow collector can be fed through the pump to the mixing area. The solid-liquid suspension to be clarified can be diluted without affecting the sedimentation process, the chemicals can be used to the optimum, and the amount of overflow fed to the mixing area can be exactly determined.