Patent ID: 6712979
Filing Date: 2004-03-30
Classification: B01D,B09C,B63B,C02F,E02F

Abstract:
A system for dredging contaminated aquatic sediments with a predetermined low moisture content, wherein said dredged sediments have a moisture content closely approximating a predetermined in-situ moisture content of the sediment sample prior to dredging, comprising:an excavator enclosed in a water-retaining housing; said housing comprising a pressure-controllable enclosure (20) having a source of air pressure continuously and sequentially applying a positive pressure equal to a predetermined external hydrostatic pressure imposed by a surrounding water column surrounding said housing, said positively applied pressure being applied from said source of positively pressurized air during a first mode of deployment of said excavator to the sediment sample, during a second mode of excavating aquatic sediments having said predetermined low moisture content and during a third mode of removal of said excavator containing the dredged aquatic sediments having said low moisture content, said excavator being hingedly attached within said housing; said excavator being capable of pivoting and extending below the bottom of the housing and being capable of pivoting and retracting into the housing between an open and closed position, respectively.