Device and method for dredging bed material under water

摘要

The invention relates to a device and method for dredging bed material under water. The device (1) comprises a vessel (4) which can be anchored to an underwater bed (2) and has a ladder (8) which can be positioned downwards at an angle (6) into the body of water (7) from the vessel (4) and which is provided with a cutting tool (10) at its free end, the cutting tool (10) comprising a number of excavating elements (103, 105) arranged around a common rotation axis (101). The cutting tool (10) comprises a passage (106) for dug-up bed material which adjoins an inlet end of a discharge means (13) for the dug-up bed material, which discharge means (13) comprises a carrier (13) for the bed material which is driven by means of a mechanical drive, which carrier comprises two conveyor belts which rotate in opposite directions of rotation across each other at the same time. The invention makes it possible to dig up underwater beds while preventing sediment spill.