Reclaiming waste rigid polystyrene foam for building material

摘要

Rigid foam, esp. formed polystyrene shapes, is granulated for use in building materials. In a processing module (3) the rigid foam is taken from a storage container (23) through a feeding device (24) to a grinder (24) which produces a wide spectrum of particle sizes. The processing module (3) is connected to a feeder and preparation module (2) which accepts the rigid foam (63) and chops it into smaller pieces (45). Between the processing module (3) and the packing stations (41,42,43) is a classifying module (4) where the particle mixture (59) is graded and stored separately. The different grades are treated separately and packed in defined quantities in the packing modules (5,6,7). Preferably a rotary drum has sieves (64,65,66) to produce three size ranges, e.g. 3,6 and 8 mm, from the ground material (59). Oversize material is recycled (49) for further grinding. Circulation through the modules is by pneumatic conveying using air from fans (16-22). The grinder (24) has a feed screw with stop/start control which is connected to a central control unit for the plant. The graded product is weighed (35,36,37), optionally blended with a binder, e.g. cement or other additive in a mixer (38,39,40) and filled (41,42,43) into plastic or textile sacks. Sensors are fitted throughout the plant to control it from a central control unit.