Patent ID: 7775371

Claim:
A device for the automatic separation of detritus in accordance with their densities, comprising: an upper feed conveyor belt which feeds the detritus to be separated; a double vibrating sieve located after said upper feed conveyor belt intended to carry out a pre-separation of the detritus which are excessively coarse and the detritus of a very small size, principally sand, including: a structure on flexible supports, driven by a vibrating mechanism, an upper sloping sieve in the interior of the structure fitted with a mesh with large openings in order to hold back detritus too large to be suitable, a lateral conveyor belt adjacent to the upper sloping sieve arranged for the removal of detritus whose size is unsuitably large, a lower sloping sieve in the interior of the structure fitted with a mesh of small openings in order to hold back the detritus of a suitable size, allowing the detritus too small to be suitable to fall through the same, a channelling at a lateral zone of the lower sieve in order to bring about the falling and guiding of the detritus held back by the same, and an outlet duct through which the detritus of a plastic or similar type are drawn; a lower conveyor belt for the removal of said small detritus; a device for cleaning by blowing including: a plenum covering the upper and lower sloping sieves of the vibrating sieve, a duct connected to the plenum, and a turbine connected to said duct in such a way that the turbine draws the detritus of a plastic and similar type through the outlet duct of the vibrating sieve; a chute through which the detritus from the channelling of the vibrating sieve are poured; and a vat provided with sloping lateral walls wherein the detritus from the chute falls into, said vat is filled with a fluid for the separation of detritus by means of flotation and decantation, further including: a supernatant conveyor belt arranged on one of the sloping lateral wall within the vat for the removal to the exterior of the vat of the supernatant, a decanted materials conveyor belt arranged on the opposite sloping lateral wall within the vat for the removal to the exterior of the vat of the decanted materials, and a bottom cleaning belt located within the vat and provided with lower transversal ridges which collect and draw the sludges which are deposited on the bottom of the vat against one of the sloping lateral wall of the vat which cause the sludges to be drawn to the exterior of the vat.