Marine Dredging Applications
Marine dredging is the process of excavating and removing material from the bottom of an ocean, river, pond, or other large bodies of water. Dredging is mainly used for marine construction projects, mining, sediment removal, environmental remediation, canal deepening, harbor maintenance, and many more.
Fly Ash Environmental Problems
1.05 billion tons of coal is burned in the United States each year leaving harmful waste (fly ash) in dumping sites. These harmful fly ash dump sites contain harmful heavy metals such as mercury, arsenic, beryllium, cadmium, chromium, nickel, and selenium.
Fly ash has a fine powdery consistency that is easily carried by the wind and can affect nearby neighborhoods and people. Breathing in fly ash overtime can irritate the respiratory system and people with existing lung diseases such as emphysema, bronchitis, and chronic obstructive pulmonary disease should avoid breathing coal fly ash dust.
Fly Ash or Coal Ash is a difficult material to pump due to its abrasive nature. Centrifugal pumps quickly get worn down and lose their tolerances and suction capabilities. This results in significant downtime and costly spare parts.
The fly ash accumulates in many stages of the power generation process and proves to be very costly and time-consuming to remove. The most troublesome stages are dealing with the lined and unlined tailings ponds, rivers, sumps, and concrete basins.
Tailings ponds and rivers continuously need to be cleaned out to increase capacity. Finding the right pump and dredging equipment can often be a complicated process. Centrifugal pumps will only pump 10-20% solids by weight. This means that most of the discharge is water and very little fly ash is coming out of the pipeline. In contrast, the EDDY Pump design can pump 50-60% solids by weight. Pump less water, more solids.
Furthermore, the abrasive nature of the fly ash destroys the impeller of the pump and causes pump failures, costly repairs and spare parts. Our pump has a high tolerance ultra-recessed rotor that withstands the destructive nature of fly ash.
Tailings ponds are often lined with plastic to minimizes the seepage of contaminants. This makes it more difficult for conventional equipment to dredge or mechanically remove the fly ash sediment without damaging the liner. We have a liner-safe wheel option for the excavator attachment.
Sumps are often the most difficult areas in a power generation plant to handle. Fly ash, coal chunks, rocks and other debris are washed into sumps and continuously need to be pumped out. Centrifugal pumps get clogged and constantly wear out because of the tolerances between the impeller and the volute.
Most Common Dredging Applications
- Marine Dredging
- Coastal Protection
- Ecosystem Restoration
- Fly Ash Dredging
- Lake Dredging
- Land Reclamation
- Beach Restoration
- Mining Dredge
- Navigation Dredging
- Port and Harbor Dredging
- Reservoir Dredging
- River Dredging
- Sand & Gravel Dredging
- Mine Tailings Dredging
We are one of the few companies who manufactures both our pumps and dredging equipment to ensure optimal support.
What is Dredging?
Industrial dredging is the process of removing sand, silt, and other solid material from the bottom of large bodies of water by using any combination of dredge pumps and material agitators or through mechanical means such as clamshell buckets. Dredging is a major service component in many major underwater construction projects to create a flat and stable foundation on the seabed. In addition, dredging is also used to maintain harbors, canals, rivers, lakes, and other bodies of water to ensure boats and large ships are able to safely pass without getting stuck in sediment build-up which occurs as sand and silt wash downstream, eventually clogging up channels and harbors. Periodically, this accumulation of material must be excavated and transported away by dredging due to large ships requiring a certain depth of water to remain operable.
Dredging Highlight Video
Problems Facing the Dredging Industry Today
There are many problems that face the dredging industry ranging from equipment problems to environmental effects. The main challenges with traditional dredging are:
- The dredge pumps routinely get clogged with sand, silt, and other debris
- The dredge pump and impeller are quickly worn down by abrasive materials
- The dredge pumps fail more often
- Longer downtimes for pump maintenance which halts production and hurts your bottom line
- Ecosystem and environmental damage stemming from high turbidity or mechanical dredging
EDDY Dredge Pump Advantages
- Non-Clog, High Viscosity, High Specific Gravity, High Abrasives, Low pH Pumping Design
- 40-70% Solids Pumping by Volume
- Ability to pump objects of up to 11-inches in diameter
- State-of-the-Art Research and Development Facilities
- 100% American Made
- Low Total Ownership Cost (See PDF)
EDDY Pump Marine Dredging Equipment
EDDY Pump provides the most innovative dredging solutions worldwide. Our team of expert pump engineers developed the EDDY Pump’s open rotor design which allows for far higher tolerances that allow for just about anything that will go into the intake to be passed through the discharge without issues. We also provide modular dredging products that can easily convert to different deployment types to ensure we have a deployment option that matches what you need for your job.
Marine Dredging Applications
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 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.
The EDDY Pump Excavator Dredge Attachment easily pins into your existing bucket linkage and is powered off of the excavators’ auxiliary hydraulics or a separate HPU. By using a cutterhead or high-pressure water jetting rings (depending on the dredging application), the patented EDDY Pump technology outperforms all centrifugal pumps in a variety of the most difficult dredging applications. The pump and cutterhead suction dredge work in conjunction to make this the optimal dredging system for handling compact material, highly viscous materials, and for pumping a high volume solids. The excavator pump attachment can easily pump slurries up to 4,500-feet without the need for a booster pump. For larger pump models and pumping distances of more than 2,000-feet, an HPU (Hydraulic Power Unit) is recommended for optimal production rates. All EDDY Pump suction dredges and excavator cutterheads are powered by our field-proven, U.S.A.-built, industrial slurry pumps.
Any excavator operator can be trained to operate the pump in just a couple of hours. In addition, this unit is completely modular and can be converted into a cable hung dredge or a diver operated dredge with little modification necessary.
For mining or construction operations where a crane is already available on site, the EDDY Pump Cable-Deployed Pump can be an ideal solution. Like many of our dredges, this cable deployed pump system comes with an optional water jetting material agitation system to fully optimize production rates. The cable-deployed pump can have an electric or hydraulic power system to meet the needs of the end-user.
The pump can be mounted off a cable, hanging off a crane and the water jetting ring is attached to the pump. It can be dropped onto the seabed as a diver operated unit and also be pinned to an excavator to become the Excavator Pump Attachment.
For ultra-precision dredging which requires diver visibility and mobility, we offer the Diver Operated Dredge Pump. This unit is completely submerged and rests on the lake bed or ocean floor and can support up to 1-3 divers at once. These diver units can be powered via electric or hydraulic depending on our client’s needs.
Our diver dredge comes equipped with over 300-ft of a suction hose that can be added to the suction inlet of the pump, providing increased versatility not commonly found in conventional diver operated dredges. This also allows for far more mobility, allowing for divers to dredge in precise locations without disrupting the pipeline. Additionally, this unit can be easily converted to a Cable-Deployed Dredge or an Excavator Pump Attachment with little modification.
Marine Dredging Case Study
The following is a real-life case study using the EDDY Excavator Dredge Attachment. We are here to help you identify your application and learn more about the ideal equipment solution to meet your needs. We are the OEM for all the tools shown.
Application: Harbor Dredging
Material: Sand, silt, wood, and other foreign debris
Equipment Used: EDDY Pump 10-inch Excavator Dredge Attachment (More Info)
The Mississippi River Dredging Challenge
Because of the strong current of the Mississippi River, a company using a self-propelled dredge was not working effectively as they’d hoped to dredge a harbor in Granite City, Illinois, located just across the water from St. Louis, Missouri. Two years ago, Budrovich, a St. Louis-based construction company, began using a 10-inch EDDY dredge pump with an excavator pump attachment to efficiently extract river material, which includes a mixture of sand, silt, wood, and other materials—the concentration and density of which varies.
The Mississippi River is one of the world’s major river systems in size, habitat diversity, and biological productivity. Barges and their tows move approximately 175 million tons of freight each year on the upper Mississippi through a system of 29 locks and dams. At the headwaters of the Mississippi, the average surface speed is about 1.2 miles per hour—roughly one-half as fast as people walk.
“Before we installed the EDDY pump, our customer was using a self-propelled dredge, which was not appropriate for the application,” said the client. “A self-propelled dredge shouldn’t be used in a body of water that has current, so it was unsafe to use it in the Mississippi River. We were looking for a different solution for the customer, and that’s when we started researching EDDY Pumps.”
The EDDY Pump Dredging Solution
The EDDY Pump and Excavator Attachment was installed on a Caterpillar 350 material handler. “The cutter head goes on the end of the boom, and we use a 700 horsepower power pack to power the effort,” Brundick explained. “We average anywhere from 180 to 200 cubic yards per hour.”
Using the equipment for about two years, the company has faced only minor issues.
“We’ve had some challenges, for example, with the seals,” she said. “But the EDDY pump team is very good on the service end of things and helped to identify and troubleshoot the problem. They asked a lot of questions about our application and about the dredge pipe, so they really know how to take a very informative effort to ensure that their equipment is right for the customer.”
The client mentioned the agility of the equipment is its best feature.
“I like that because it’s on the boom of an excavator you have some room to play with the pump placement,” she explained. “You can also hook it to a crane. The EDDY Pump can go into areas where a large dredge could not fit. In order for it to be effective, it always needs to have a constant source of water. If you are dredging in a pond, you just have to make sure you keep a constant source of water. We don’t have this issue while dredging a river.”
Environmental Dredging and Remediation
Environmental dredging generally refers to remediation dredging or removing contaminated materials from specific underwater areas. Environmental dredges are built to be as precise as possible with extremely low turbidity to prevent material agitation of the surrounding ecosystem. A low turbidity dredge will greatly help keep the contaminated material from resuspension, which would allow the dangerous material to spread over a wider area, making things worse. Environmental dredges are typically equipped with video cameras, GPS, RTK for precise positioning, and/or sonar monitoring instruments to oversee the entire dredging process. This allows the process to be much more controlled over a navigational or construction dredging, ensuring the contaminated material is captured as safely as possible.
Similar to other industrial processes, regular maintenance is required to keep the dredging system functional and free of any issues. Maintenance dredging is used to deepen or maintain navigable waterways or channels that have become silted. These waterways can become too shallow to navigate if sediment is left unmanaged. Lagoons and settling tanks are notorious for rapid sedimentation buildup, which needs to be removed on an annual basis to avoid reduced holding capacity, gunk/odor buildup and murky water.