To provide an soil loosening hopper preventing clogging of sludge in a pre-treatment step, and efficiently crushing earth lumps of large diameters.

The soil loosening hopper comprises a casing having openings in an upper face and a lower face, a main treatment part disposed right above the opening of the lower face of the casing, and a pair of soil-loosening promoting rotary shafts disposed above the main treatment part and near right and left inner walls of the casing. The main treatment part comprises a plurality of rotary shafts crossing the inside of the casing and continuously connected with each other in parallel. An soil loosening means crushing earth lumps in earth and sand supplied into the casing is provided on circumferential faces of the soil loosening promoting rotary shafts and rotary shafts of the main treatment part. A part from a height position where the soil loosening promoting rotary shafts are disposed to the opening of the lower face of the casing out of the right and left inner walls of the casing, forms a tilted face, and the casing is formed tapered toward below.

COPYRIGHT: (C)2008,JPO&INPIT