floating grab dredgers
Floating grab dredgers are used on standing water bodies for the wet excavation of sand and gravel with a depth of 10 m up to more than 100 m. The floating grab dredgers do not have an own drive, they are positioned on the quarry pond by using mooring and anchoring winches.
With floating grab dredgers hard and ductile layers can be broken through.
They can be equipped with a rope grab or a hydraulic grab.
For the forwarding of the material by floating conveyors the batch mode of the grab will be changed to a continous process by using a hopper. For reaching the necessary residual moisture for a forwarding by floating conveyors, in general a dewatering-screener is used.
The fines material falls back to the quarry pond or can be recovered by using a fine sand recovery system like pump and cyclone or by using a sand processing plant like washing system, pump, cyclone and dewatering-screener.
All floating grab dredgers are equipped with latest drive technology, including programmable logic controller (PLC), global positioning system (GPS), depth sonar and production data acquisition (PDA) systems.
In general following types are applied:
|floating grab dredger type boom|
|floating grab dredger type tower|
|floating grab dredger type gantry|
|floating grab dredger type portal|