A search robot system first divides the entire area of disaster into a mesh cell of an appropriate size, and arranges a search robot for each mesh cell. The system includes a separate module associated with each of the plurality of generator sets. The compressed solvent can be recycled and the process is continuous. Therefore, a disadvantage that a side edge of the sheet is caught in a joint can be prevented. Load on an electric motor 3 or the like for rotating the screw 2 or a value corresponding to the load is measured, and if the value is equal to or larger than a preset upper limit value, a screw shaft 2a is lifted up to increase a gap between an edge of the screw blade 2b and a bottom portion of the casing 1.