PURPOSE: To improve dehydration efficiency and treating capacity by providing a liquid leakage preventive means between the central disk arm and filter plates of the circular conical screen type continuous compression dehydrating machine.

CONSTITUTION: The pressure resistant liquid leakage preventive means is proved between the central disk arm 5 and the circular conical filter plates 8 to prevent the leaking out of raw materials to a cake discharge port 3 side and the consequent short circuiting. The raw materials are force-fed through a raw material supplying port 15 into the max. spacing part 11a of the circular conical filter plates 8 by a raw material supplying pump 16. Dehydration is executed by the force feeding and the raw materials are moved to the min. spacing part 11b by the rotation of the circular conical filter plates 8. The spacing between the two filter plates 8 is reduced, by which the raw materials are dehydrated to cake. The cake is released by a scraper 8 to the outside of the dehydrating machine 1 via a cake discharge port 3. The dehydration efficiency is improved and the treating capacity is improved.