A particle separator is disclosed for a first fluid that includes solid particles of different sizes dispersed therein includes a flow path of the first fluid. A chamber is disposed below the first fluid flow path. The chamber includes an open upper portion adjacent to and below the first fluid flow path. A second fluid at a second density greater than the first density is disposed in the chamber. The second fluid is in contact with the first fluid flow path at the chamber open upper portion.

Systems and methods for separating heavier from lighter materials in mixed auto shredder residue (ASR) from end-of-life vehicles. Vehicles are shredded and the resulting mixed ASR is fed into a system that efficiently segregates heavier (typically metal) from lighter (typically plastic) pieces. The system has an inlet feed chute angled downward to a lower end over a separator tank filled with water. One or more nozzles configured to introduce water at a velocity into the separator tank create a flow of water across the tank to push smaller and lighter particles over an exit weir. Heavier particles sink toward a heavy matter removal conveyor having a lower end positioned within the separator tank so that the heavier particles are transported upward out of the separator tank. The heavy matter removal conveyor may be one or more Archimedes screws, a flat, ribbed or cleated conveyor, or a drag chain.

An apparatus for separating solid materials is described, which comprises a channel for receiving a liquid and the materials to be separated, the channel being provided with an agitation surface. Means for directing streams of fluid at the materials to be separated are provided, the streams of fluid urging the materials over and against the agitation surface to separate the materials. Heavier material is urged along the bottom of the channel to an exit under the action of the streams of fluid, and lighter material separated from the heavier material rises to the surface of the liquid. The agitation surface comprises a plurality of formations each extending across at least a portion of the width of the channel, each formation comprising an ascending surface and a descending surface, at least part of the ascending surface having a steeper slope with respect to the base of the channel than the descending surface. It has been found that the shallower descending surface of one formation followed by the steeper ascending surface of the next formation provides an improvement in agitation of the solid materials as they progress down the descending surface and start to progress up the ascending surface, keeps the transition from the descending surface to the ascending surface clear of a build-up of materials, and provides for the lighter materials to be urged upwards at a suitable angle to reach the surface for removal.