To provide a backwashing machine using a centrifugal force by rotation of a bottomed cylindrical container having a through hole for filtration on the peripheral side surface, while clogging the filtering through hole while maintaining the food pressing pressure and the duration optimum And to provide an operating method of a bread strawing machine and an automatic backwashing device capable of optimally maintaining the backwashing action.SOLUTION: A vertical bottomed cylindrical container supported rotatably around a central axis and provided with a through hole for filtration on the peripheral side plate, a cylindrical bottomed cylindrical container which is located inside the bottomed cylindrical container and has an inner peripheral surface A rotatable pusher supported so as to be rotatable around the central axis while abutting or in close proximity to the rotatable pusher, a filtration object catch for collecting a filtrate discharged from the filtering through hole of the bottomed cylindrical container to the outside of the container And a collecting member. While rotating the bottomed cylindrical container charged with the object to be backworked at a first rotation speed in a predetermined rotation direction, the rotary presser is moved in the same rotation direction as the bottomed cylindrical container At a first rotational speed and a second rotational speed having a predetermined speed difference between the first rotational speed.(FIG.【課題】周側面に濾過用透孔を有する有底円筒状容器の回転による遠心力を利用する裏漉し機において、食材押し付け圧力及び継続時間を最適に維持しつつも濾過用透孔の目詰まりを解消し、裏漉し作用を最適に維持可能な裏漉し機の運転方法及び自動裏漉し装置を提供する。【解決手段】中心軸の回りに回転自在に支持され周側板には濾過用透孔が明けられた縦型有底円筒状容器と、有底円筒状容器の内側にあって周側板内周面と当接又は近接しつつ中心軸の周りに回転可能に支持された回転押圧子と、有底円筒状容器の濾過用透孔から容器外へと放出される濾過物を捕集する濾過物捕集部材とを有し、裏漉し対象物が投入された有底円筒状容器を所定の回転方向へと第1の回転速度で回転させながら、回転押圧子を有底円筒状容器と同一回転方向へと第1の回転速度の間に所定の速度差を有する第2の回転速度で回転させるステップを包含する。【選択図】図8
