PURPOSE: To permit gravitating dehydration needed for the separation of solid matter by introducing the vibration into the charging chamber of a separator and reducing the viscosity of slimy liquid.

CONSTITUTION: In order to introduce the vibration component in the vertical direction into the slimy liquid, a stabilizer 10 constituted as a link, is disposed in the fitting plate 9 of a vibrator and the stabilizer 10 is guided with the vibrator 4 at the one side and connected with the casing of the compress-screw type separator at a swing supporting point side. Since the introduced vibration improves the fluid characteristic of the slimy liquid, the liquid can flow out through gaps in a screening cage 12. A screw 14 driven by a motor 13 provided with a transmission catches the solid matter in concentration and the solid matter is forcedly fed into a compressing zone 15 in the separator to more dehydrate the solid matter.