Patent ID: 8312809

Claim:
A screw press, with small dimensions, particularly suitable for the compaction of solid waste for disposal, also using sorted-waste collection, the screw press comprising an initial first large-diameter screw section with wide-pitch helices, communicating laterally with a bottom opening of a loading hopper in order to remove material from the hopper and feed the material to a following second small-diameter screw section with small-pitch helices, surrounded by an internally scored stator body so as to produce the feeding and compaction of the material which also occurs in conjunction with the action of a constrictor which acts on the discharge mouth of the second screw section, the first and second screw sections being separated and arranged above one another and/or situated partly alongside each other but at different heights, so as to form overall a press which has a length corresponding to the length of the longer of the two screw sections, the two screw sections being operated at different speeds, with the second screw section rotating at a speed greater than that of the first screw section, and the first screw section having a direction of extension of its helices which is opposite to that of the helices of the second screw section so that, when the two screw sections rotate in the same direction, the first screw section moves the material in the opposite direction to that moved by the second screw section, the loading hopper being provided with a partly rounded bottom having its center on an axis of the first screw section, with inner and longitudinal scoring, and at the bottom and along the side of the rounded part, the hopper being provided, approximately halfway along the length of its bottom, about the distal end of the first screw section, with a window towards which the first screw section pushes the material which is immediately taken up by the second screw section which operates in a lower extension or bottom part of the hopper and has a rounded profile with a curvature along an axis of the second screw section, the axes of the first and second screw sections being parallel to each other, and the diameter of the first screw section being larger than the diameter of the second screw section.