JPS5914318B

PURPOSE:To provide a dehydrator having upper and lower belts for compression dehydration, wherein projections and recesses are respectively provided on the surfaces of the belts and a sludge is dehydrated by engaging the projections with the recesses. CONSTITUTION:A projection-type upper loop belt and a recess-type lower loop belt are provided which are moved by sprocket wheels 3, 4. The upper belt is provided with a pressing means operated by a hydrualic cylinder and a vacuum chute, while the lower belt is provided with a vacuum chute. When a sludge is fed into the recesses of the lower belt, the projections and the recesses of the belts are engaged with each other to dehydrate the sludge in the recess through compression, and suction dehydration is simultaneously performed by the vacuum chutes. By using this dehydrator, a sludge cake having a degree of dehydration higher than those achieved by the conventional dehydrators can be obtained.