Dredging

Common Pump Issues in Dredging

There are many problems, both environmental and mechanical, that can affect dredge pumps and equipment. The main challenges with industrial dredging are:

• Dredge pump or discharge line becomes clogged with sand, silt, and other debris
• The abrasive nature of dredging sand quickly wears down the metal pump and internals leading to failures
• More maintenance which can shut down the operation
• Environmental concerns

Dredging is referred to as the process of transporting underwater sediments, typically sand or small rocks, from one region to another. Dredging occurs in shallow waters including lakes, rivers, or oceans for the purpose of land reclamation, desilting, flood prevention, creation of new ports, or expansion of existing ports. Dredging utilizes specialized pumps designed to handle abrasive solids more effectively than that of a standard centrifugal or water pump. Standard pumps not typically used for dredging as they tend to be quickly beaten down and worn out from the constant bombardment of abrasive materials, requiring frequent costly maintenance.

Dredge pumps are a special category of heavy-duty slurry pumps that are utilized in the process of dredging. Hence, various industries that utilize dredge pumps are the construction industry, mining industry, the coal industry, and oil & gas industry.

Marine Construction

Marine construction can describe a wide variety of structures that are typically built on the shore such as piers or seawalls or offshore as with oil rigs and cofferdams. To be successful at marine construction, it requires the use of heavy-duty dredge pumps to efficiently remove sediment to ensure operation has a solid, even foundation on which to build from. Marine dredging is the most common way to excavate underwater.

Harbor and Canal Maintenance

Marine dredging also refers to harbor and canal management. Over time, sediment builds up in harbors, canals, rivers, and lakes. Canal management involves dredging sand from the ocean floor which ensures large ships can get pass safely without contacting the floor sediment. GPS positioning systems and slurry flow meters are typically used to ensure accuracy and optimal production rates. Since large container ships carry the bulk of the world’s trade goods, marine dredging is widely considered a critical cog in the global economy.

Lake Dredging

Lake dredging is the process of removing sediment from freshwater lakes. Lake dredging is typically performed due to siltation, nutrient buildup, and toxic contaminant problems found in the lake.

Siltation is when there is an excess amount of sediment buildup which can cause discolored, cloudy water. Siltation is typically caused by soil erosion or sediment spill. As a result, dredging is used to remove the excess sediment in order to restore the natural beauty of the lake.

Nutrient buildup describes the accumulation of certain nutrients such as Phosphorus (P) and Nitrogen (N). These nutrients are essential to plants and algae for strong growth. The amount of nutrients in lakes is heavily determined by the type of land, vegetation, and types of rock and bedrock. Excess buildup of nutrients (especially Phosphorus) can also promote unwanted growth or production of algae and plants.

Toxic containment is the process of removing toxic or hazardous sediment while being careful not to further contaminate the surrounding ecosystem in the process. Low-turbidity, hydraulic dredge pumps are most commonly used to safely remove contaminated material. GPS dredge positioning systems are used which allow operators to dredge with far more precision. Knowing where your pump is located beneath the water and knowing where you’ve dredged is critical in toxic containment scenarios.