Cutter suction dredgers, commonly known as CSDs, represent a pivotal category within hydraulic dredging vessels due to their versatile capabilities. These innovative vessels masterfully navigate through a spectrum of terrains, from soft sands to formidable rocks, making them indispensable where conventional methods fall short. By seamlessly blending the principles of excavation and suction, CSDs efficiently dislodge and transport a diverse range of materials, including clay, soft rock, and compacted soils. Their adaptability positions them as the go-to choice for an array of projects, from land reclamation and port construction to environmental dredging and hydropower excavation. How do you know about the Cutter Suction Dredger? Let’s learn about the cutter suction dredger in this article.
1. What’s development and application of cutter suction dredger?
1.1 The development of cutter suction dredgers.
In recent years, my country’s economic development has made great progress, and the importance of dredging projects has gradually been paid attention to, making dredging ships gradually develop in the direction of large-scale and intensive. The production capacity of cutter suction dredgers has increased from 800m3/h in the past to It has rapidly increased to 4000m3/h, but it still cannot catch up with the pace of developed countries. For example, Europe has produced a large-scale cutter suction dredger with a capacity of 6500m3/h a few years ago. Improving the production efficiency of cutter suction dredgers will inevitably put forward great requirements on parts, and will also cause wear and tear on parts.
1.2 Application of cutter suction draught vessel.
In China, there are a large number of rivers, lakes and seas, with a wide range of river basins. Many river basins have a high sand content, which causes serious siltation at the river estuaries and serious damage to the ecological environment. It will also seriously hinder the discharge of sand and floods in rivers. Therefore, corresponding measures must be taken to deal with the siltation problem of rivers. Dredgers are used in dredging projects, and the type of dredger should be selected according to the meteorological, hydrological and geographical environmental characteristics of the dredging project. During the operation of the dredger, the main components will be impacted and rubbed by hard materials such as sand and gravel in the water, so the materials of the components need to have high wear resistance. Special attention should be paid to the wear detection of the dredger cutter.
2. What’s the Cutter Suction Dredger?
A cutter suction dredger is a stationary dredger equipped with a cutting device that dredges silt and soil, and then the slurry is sucked in by a dredging pump.
The hull does not have a propulsion device / optional propulsion equipment (small size can also meet the propulsion requirements). Self-propelled, specially designed ocean-going hull. Whether it can be self-propelled or not, the cutter suction dredger needs to be fixed in position with positioning piles before it can start working. The cutter disc is a mechanical rotating tool that can cut hard soil or rock into pieces. By pulling the winch to make the winch move in a fan-shaped motion, the rotating cutter disc can enter the water and swing in the soil. It is installed in front of the suction head, and the cut soil and rock are directly sent to the mud treatment area through the strong suction of the dredging pump.
3. What is the working principle of the dredger?
The hull of the cutter suction dredger carries most of the workpieces. Its main working principle is to use the buoyancy of water to transport the diesel engine, pump, workbench, gearbox, hydraulic motor, etc. to the water surface.
The suction head is mainly responsible for rotating the sludge at the bottom of the pool into a twisted leaf shape, making the sludge boil. The sand pump sucks out the sludge through the underwater suction pipe and then transports it to the designated location on the coast through the discharge pipe. The suction head twists and sinks under the action of gravity and has good contact with the bottom of the pool.
The cutter suction frame of the cutter suction dredger is driven to rotate by a hydraulic motor. Under the reaction force of the cutter suction knife, the entire hull rotates in the water with the positioning pile as the fulcrum.
The entire working principle is diesel engine, gearbox, gear pump, reamer suction pipe. Due to the high-speed centrifugal force generated when the mud pump is running, the diesel engine oil pump, hydraulic cylinder, and hydraulic motor drive the reamer suction shaft to rotate.
Therefore, the working principle of the mud dredger can be summarized as follows: the suction head stirs the mud to make the sucked mud high and stable in concentration, while vibrating the entire hull, so the replacement of the pile allows the hull to move forward, making the walking simple and reliable, and the mud pump transports the mud to the designated location on the coast.
4. What is the impact of hydraulic reamer on cutter suction dredger?
4.1 What is the location and structure of the hydraulic reamer?
As the core excavation component of the dredger suction dredger, the dredger cutter head is installed at the entrance of the suction pipe at the end of the bridge to cut the soil. For the cutting system of the dredger suction dredger, the operating efficiency of the cutter will directly affect the operating effect of the system. In terms of structural composition, the cutter head consists of a hub, a cutter seat and a cutter arm . The toothed cutter head has detachable teeth. Among them, the hub plays a transmission role and can be connected to the drive shaft through keyways, threads, etc. The cutter seat is used to fix the cutter arm and the cutter head. The cutter arm is distributed on the periphery of the cutter head and can directly cut the soil. It is usually composed of 5 to 6 cutter teeth. The number of cutter arms will affect the cutting force of the dredger cutter head. The more cutter arms there are, the smaller the opening width of the cutter head is, and the smaller the maximum cutting thickness that can be achieved during construction.
4.2 The process of hydraulic reamer of Cutter suction dredger?
The use of a new gradient remanufacturing process can better solve the contradiction between the wear resistance and fracture resistance of dredger bucket teeth, reduce the weight of dredger bucket teeth, extend the life of dredger bucket teeth, improve the efficiency of dredger bucket teeth, and make dredger bucket teeth have good remanufacturing performance.
4.3 What factors affect the operation of the reamer?
The cutter suction dredger is simple to operate and easy to control. The dredger relies on the hull trolley for positioning and stepping on steel piles. It uses the steel cables on both sides of the auger arm and the anchors fixed on both sides of the dredging trough, and is pulled by the winch to swing the two sides to cut the mud and sand. The cutter suction dredger operates under the condition of controlling the swing angle, and the mud sucked by the dredger is pumped to the storage site through the mud pipe. However, when the existing cutter suction dredger is operating, because the auger cannot fully and thoroughly crush the mud and sand, there will always be some larger mud blocks sucked into the mud pipe, causing the mud pump to fail to work normally. This abnormal condition makes it difficult for the dredger to continue to operate for a long time.
4.4 What improvements have we made to hydraulic reamers?
The reamer head is one of the important equipment of the cutter suction dredger. Its mud suction ability will have a significant impact on the dredging efficiency of the entire dredger. When the dredger is performing cleaning operations, it often encounters some scattered shallow points that are difficult to remove and are particularly difficult to eliminate . These grooves are affected by the surrounding environment (wind flow) and the design of the raker head itself. The sharper the groove, the more likely it is to slide, resulting in false sweeping and failure to eliminate the groove, resulting in reduced ship production, reduced construction efficiency, increased daily fuel consumption, and increased ship costs.
In order to solve the contradiction between the wear resistance and weldability of the dredger cutter head and improve the life of the cutter blade, starting from the basic principle of remanufacturing of wearing parts, according to the dredging operation conditions of the dredger blade, the blade teeth are remanufactured for wear resistance, working reliability, etc. to meet the requirements of the cutter suction dredger. The use of a new gradient remanufacturing process can better solve the contradiction between the wear resistance and fracture resistance of the dredger teeth, reduce the weight of the cutter blade, extend its life, improve dredging efficiency, and make the dredger cutter head have good remanufacturing performance.
5. Conclusion
Cutter Suction Dredgers are a type of water conservancy engineering equipment with far-reaching influence, and they play a vital role in water conservancy projects. With the continuous advancement of science and technology, the development of cutter suction dredgers is also changing with each passing day, and their structures are becoming more and more perfect. The basic principle is to peel off the soil through a rotating cutting tool, and then pump the soil away through a suction pipe, so as to achieve efficient dredging operations. Cutter suction dredgers can handle various types of soil, including sand, mud, rock, etc., so they are widely used in port construction, waterway maintenance, mining, reservoir and hydropower lake excavation, and environmental dredging.
In cutter suction dredgers, reamer plays a vital role. The reamer is a key component for the cutter suction dredger to cut and strip the soil, which directly affects the dredging efficiency and quality. By continuously optimizing the design and materials of the reamer, the dredging efficiency of the cutter suction dredger can be improved, the cost can be reduced, and the impact on the environment can be reduced. Therefore, the importance of the reamer is self-evident, and it is the key to the efficient completion of various dredging projects by the cutter suction dredger.
In short, with the widespread application of cutter suction dredgers in water conservancy projects, their structures are constantly optimized and their application fields are constantly expanding. As their core components, reamer plays an irreplaceable role in improving dredging efficiency and quality. The development of cutter suction dredgers will continue to promote progress in the field of water conservancy projects and provide strong technical support for various water conservancy projects.
