CUTTER SUCTION DREDGER
• When mechanical arm with reamer head is in the water, it would disturb deposits when sucking mud underwater. Some suspended matters would diffuse from the lateral to the water, thus causing secondary pollution
• The dredger would disturb the dredged soil and twist the upper floating mud (or drift mud) with the lower sediment (or undisturbed soil), so that the content of nutrient salt or heavy metals in the surface layer of the sediment after dredging is still high
• Generally the mud discharge concentration is 10-15% of the underwater mud volume when dredging by cutter suction dredger. However, the thickness of the floating mud (or drift mud) is much smaller than the diameter of the reamer, so the mud discharge concentration will be lower, the volume of residual water generated by mud discharge will be extremely large, the mud-dumping yard needed shall be large too, the construction period will be extended and engineering investment will be increased
GRAB DREDGER
• It is difficult to grab floating mud (or drift mud) underwater during construction
• Most upper floating mud (or drift mud) will overflow from the gap or upper part of the grab to the water, causing secondary pollution
• Grab dredger would disturb the floating mud layer and consume soluble oxygen in the water, causing water become turbid and leading to death of fish and shrimp
• There is still a lot of nutrient salt or heavy metal left in the sediment after dredging. The dredging effect is bad
• When mud barge transports the dredged soil to the mud-dumping yard, hydraulic excavation machine is needed to blow the mud to the mud- dumping yard. The final mud discharge concentration is similar to that of the cutter suction dredger. As concentration becomes lower, the mud-dumping yard needed will be larger, the construction period will be extended and engineering investment also needs increasing
ADVANTAGES OF HAICHENHUA PNEUMATIC SUCTION PUMP DREDGING SYSTEM
