| 摘要 |
PROBLEM TO BE SOLVED: To enhance collection efficiency for collecting sedimentary sand on a sedimentation basin to a sand collection pit for improving grit efficiency.SOLUTION: In a grit method in which sand is collected to a sand collection pit by jetting pressure water in a drain state, via a main trough, and the sand is sucked and transferred by a grit device, a drain state is set when a water level is at an intermediate point between the highest point and lowest point of a bottom part of the main trough. |
