Dredging system and method for dredging

Abstract

A dredging system for removing submerged granular material from a bottom surface is presented. The dredging system comprises a dredging robot for removing granular material and a docking station for offloading removed granular material from the dredging robot. The docking station is attached and fixed in connection to the bottom. The dredging system further comprises a riser pipe for transporting removed granular material from the docking station to a remote location. A method for dredging of submerged granular material is also presented.

1 . A dredging system for removing submerged granular material from a bottom surface, the dredging system comprising:
 at least one dredging robot for removing granular material and multiple docking stations for offloading removed granular material from the at least one dredging robot, wherein the docking stations are attached in relation to a bottom surface thus providing a fixed and permanent location that is unaffected by elements such as waves, water current, motion, and tide, wherein the at least one dredging robot is adapted to shuttle between the multiple docking stations and comprises a control unit configured to operate the at least one dredging robot by remote control, semi-autonomously and/or autonomously;   a docking coupling configured to offload removed granular material and comprising an electrical outlet provided on each docking station;   wherein the at least one dredging robot includes at least one of: a coupling configured to be connected to the docking coupling provided on each docking station and a coupling on an umbilical line for coupling the docking station to a dredging robot;   at least one riser pipe for transporting removed granular material from the multiple docking stations to a remote location.   
     
     
         2 . The dredging system of  claim 1 , wherein the dredging robot is a bottom crawler or a submersible drone. 
     
     
         3 . The dredging system of  claim 1 , wherein the dredging robot comprises at least one suction head for removing granular material. 
     
     
         4 . The dredging system of  claim 3 , wherein the suction head comprises one or more fluidizing nozzles. 
     
     
         5 . The dredging system of  claim 1 , wherein the dredging robot comprises one or more shearing elements, for loosening of the submerged granular material, and wherein the one or more shearing elements comprise teeth, blades, knives, rotating blades, spiked rollers and/or nozzles for emitting high-pressure fluid jets. 
     
     
         6 . The dredging system of  claim 1 , wherein the dredging robot comprises a tank for temporary storage of removed granular material. 
     
     
         7 . The dredging system of  claim 6 , wherein the dredging robot comprises a battery for providing power to the dredging robot. 
     
     
         8 . The dredging system of  claim 6 , further comprising a power line connected to the dredging robot, for providing power to the dredging robot. 
     
     
         9 . The dredging system of  claim 1 , further comprising an umbilical line for offloading removed granular material from the dredging robot, wherein the umbilical line connects the dredging robot with the docking station. 
     
     
         10 . The dredging system of  claim 9 , wherein the umbilical line comprises a power line for providing power to the dredging robot, and optionally one or more of an integrated communications line, a compressed-gas line, at least one hydraulic line and/or a lubrication line. 
     
     
         11 . The dredging system of  claim 1 , wherein the dredging robot comprises an underwater positioning system. 
     
     
         12 . The dredging system of  claim 1 , further comprising conveying means for conveying removed granular material through the riser pipe. 
     
     
         13 . The dredging system of  claim 12 , wherein the conveying means comprises a slurry pump, an eductor, or a compressor, and wherein the conveying means optionally further comprises a booster pump. 
     
     
         14 . The dredging system of  claim 1 , wherein two or more docking stations are connected with a connecting pipe to a riser pipe. 
     
     
         15 . The dredging system of  claim 1 , comprising multiple dredging robots. 
     
     
         16 . The dredging system of  claim 1 , comprising at least one docking station with several docking couplings for simultaneous docking of one or more dredging robots. 
     
     
         17 . Use of a dredging system of  claim 1 , for a mining operation, a coastal reinforcement operation, the construction of an artificial peninsula or artificial island, the anchoring of equipment or the laying of cables or pipes, a salvage operation for releasing a stranded or sunk vessel, the removing of granular material from behind an artificial dam or from a mine or tunnel, the removing of granular material from a vessel, a container or a basin, and/or the dredging of a waterway, such as a channel, a river, a lake, a harbor, or a marine navigation channel. 
     
     
         18 . Method for dredging of submerged granular material, comprising:
 providing a dredging system according to  claim 1 ;   removing granular material with the dredging robot;   offloading removed granular material from the dredging robot to the docking station; and   transporting removed granular material from the docking station to a remote location through the riser pipe.   
     
     
         19 . Method according to  claim 18 , further comprising instructing the at least one dredging system to remove granular material at one or more dredging locations during one or more time-intervals.