PISTON PRESS

PROBLEM TO BE SOLVED: To obtain a piston press by which solid and liq. are continuously and efficiently separated from a solid-liq. mixture. SOLUTION: This piston press is provided with a cylinder 13 into which a solid.-liq. mixture is introduced and with at least a part of the side wall formed from a filter screen 12 for discharging the liq. in the mixture, a position 14 capable of being freely reciprocated in the cylinder 13 and a discharge valve 21 provided at the bottom of the cylinder 13, capable of being reciprocated with respect to the cylinder, with an inclined face for conducting the solid component in the mixture from the central part to the peripheral part formed and discharging the solid component from a gap between the peripheral part 21a and the cylinder 13.