Outer cylinder screen washing apparatus of screw press

A washing pipe is mounted on a washing guide provided on an outer side of an outer cylinder screen of the screw press and includes a washing pipe body and washing nozzles provided in the washing pipe body and configured to discharge washing liquid flowing from an inside of the washing pipe body toward the outer cylinder screen. A washing pipe swing supporter is configured to support the washing guide to allow the washing pipe to swing between a discharge position and a separation position. The discharge position is a position where the washing pipe is mounted on the washing guide and the washing liquid is discharged from the washing nozzles toward the outer cylinder screen. The separation position is a position where the washing nozzles are farther away from the outer cylinder screen than in a state where the washing pipe is positioned at the discharge position.