中文
In dredging operations, the sludge discharge hose string system is a key channel connecting dredging equipment and material accumulation sites, and its operating status directly affects overall productivity. While pipe blockage is a common problem, it can lead to serious consequences such as unexpected downtime, a sharp drop in output, and soaring maintenance costs. If we accurately understand the causes of blockages and master effective countermeasures, it will be crucial to ensuring the continuity and economy of dredging operations.
Typical causes of blockage
Pipe blockages are rarely caused by a single factor; they are usually the result of a combination of factors. Common causes include:
● Insufficient flow rate: When the slurry flow rate is lower than the critical settling velocity of the material, solid particles are deposited and gradually accumulate at the bottom of the String.
● Strong material adhesion: High-clay or high-plasticity slurries increase adhesion to pipe walls, easily forming a viscous deposit layer.
● Abnormal object entry: Large particles or debris enter the pipeline, exceeding its designed conveying capacity.
● Poor String layout: Sharp bends, sags, or hose collapses increase local flow resistance and accelerate deposition.
When the above conditions are present simultaneously, sediment will accumulate rapidly, eventually forming a partial or complete blockage.
Identification methods in operation
Early detection is key to minimizing losses. Operators should closely monitor the following operating indicators:
● Abnormal pressure: The dredging pump's drainage pressure increased significantly, while the pump inlet suction vacuum pressure decreased.
● Load changes: The engine load actually decreased under continuous pumping conditions.
Areas prone to blockages include pipe diameter transition sections, underwater pipe sections, crossings, and drooping floating hose strings. The above symptoms are particularly pronounced when dredging coarse-grained, plastic clay, or mixed soils, and require close monitoring.
Corrective measures
If a blockage is suspected, systemic action should be taken swiftly:
1. Adjust operating parameters
Pause lateral movement
Raise the bridge frame
Reduce slurry concentration
Increase pump speed to stabilize outlet pressure
2. Inspection along the route
If adjustments are ineffective, immediately inspect each section of the pipeline route to locate the blockage and assess its severity.
3. Mechanical removal
If the adjustment fails, the affected pipe section should be disconnected and the blockage manually removed.
Prevention strategies
Long-term stability depends on proper design and standardized operation, with key aspects including:
● Flow rate control: Maintain the flow velocity in the pipeline higher than the critical settling velocity of the material. The critical flow velocity is affected by factors such as particle size and pipe diameter; the larger the particle size and the larger the pipe diameter, the higher the required critical flow velocity.
● Optimized layout: Pipes should be kept as straight as possible, avoiding sharp bends and hose collapses. In floating or flexible connection sections, using CDSR dredging hoses with smooth inner walls in conjunction with floats can effectively prevent localized stagnation caused by hose collapse.
● Regular inspections: Pay special attention to the pipe diameter transition section and bottleneck point, ensuring that their diameter is greater than the feed grid spacing.
● Concentration Management: When dredging large particles or plastic clay, strictly control the slurry concentration, especially to prevent flow interruption caused by sudden pump stoppage.
Date: 26 Aug 2026