DREDGING DEVICE

PURPOSE:To prevent muddy water from its diffusion by surrounding a conveyer by a case, rotatably providing a dredging mouth provided with an obstacle removing iron lattice in a lower end of the case, and connecting a circulating path to an upper part of the dredging mouth. CONSTITUTION:An upper end of a conveyer 1, surrounded by a case 1a, is rotatably fixed to a derrick 10 of a ship body M, and the conveyer is obliquely hung down to the bottom of water by a suspension wire 20 to dredge earth and sand (m) in the water bottom by rotating the conveyer 1. Next, a dredging mouth 2, whose rotation is adjusted by a hydraulic cylinder 2a, is rotatably provided in a lower end of the case 1a to connect two circulating paths 3, connected to the case 1a, to the mouth 2. Then, a scraper plate 4 is forced to lower down in the water according to rotating the conveyer 1, and a negative pressure is generated in a suction port 3a of the circulating path 3 to suck up muddy water from the suction port 3a recirculated in the case 1a. In this way, the muddy water can be prevented from its diffusion.