GIW Industries, the leader in the design, manufacture and application of heavy duty, centrifugal slurry pumps, announced the application of its hard-wearing double-wall pumps in Lianyungang, China. This project marks GIW’s first collaboration with the Lianyungang Harbor Bureau, which has launched a new dredging vessel to perform much-needed maintenance and new work in the Lianyungang Harbor.
Cutter suction dredges (CSDs) must deal with excessive amounts of rock and hardened soil. When the Lianyungang Harbor Bureau, which operates and oversees regular maintenance of the harbor, began the process of building a new CSD, it needed pumps that could endure the area’s extremely harsh conditions. Not only must CSDs cut through rock and hardened silt, but they must also pump the slurry to the shore, which can be as far as 6km away.
In this case, the new CSD is being used for maintenance purposes and also to cut a passage for a new bridge being built in the harbor. The vessel is equipped with a large, submerged mechanical cutter located in front of a GIW-supplied MHD 72 submersible pump. This pump delivers cut material to the first inboard pump, a DWD 84; from there, material is delivered to shore through a floating, adjustable pipeline. Depending on the length of the pipeline, a second DWD 84 pump located on the dredge may be used as a booster. These two pumps, pressure-rated at 30 bar each, can pump slurry over a distance of 6km when operated in series.
The Lianyungang Harbor Bureau chose GIW’s DWD 84 pumps for their excellent wear life, lower fuel costs due to their high hydraulic efficiency, and robust mechanical construction. The main wear parts of these pumps are made of proprietary GIW materials that provide a high degree of wear resistance. The impellers are made of GIW’s Gasite WD29G toughness, enabling the pumps to handle large rocks and hard soil.
The pumps’ double-wall design meets Chinese dredge industry safety requirements. The design also provides an extra measure of protection against flooding hazards in case of catastrophic failure and extends the shell wear life. The 29G can withstand abrasion and impact by the large rocks dislodged by the cutter.
Each 70t (154,000lb) pump has a 30-bar (435psi) maximum allowable working pressure rating, a 45-bar (653psi) hydro test pressure, and a flow rate of 13,000m3/h (57,200gpm).
This was the Lianyungang Harbor Bureau’s first collaboration with GIW. The Bureau typically contracts such work to dredge contractors, explains GIW Region Manager for Global Dredge, Asia and Europe Jonathan Samuel. Delivery required a coordinated effort between GIW, GIW group company KSB China’s personnel, a manufacturing partner in China and the Lianyungang Harbor Bureau.
Samuel explained, "The LSA pump parts were designed and engineered in Grovetown, GA, US. All the high chrome wear parts (the inner shells, the liners, the impellers) and the mechanical end bearing assembly and pedestal were manufactured at our US factory and exported to China.
"We also sent GIW engineers to China to make sure the outer casings were built correctly and to supervise the assembly and testing of the pumps," he says. "The cooling system and sand/water separators were also built in China."
After being assembled and tested, the pumps were then disassembled, sent to the shipyard, rebuilt, and installed into the vessel. The new ship’s deck was closed after all the equipment was mounted in place.
"The project required quite a bit of engineering, supply chain, and logistics work," says Samuel. "In everything from quality to engineering to language to standards to design criteria, our dedicated project managers, engineers, and the team in China were vital to the project’s success."
Commissioned in December 2012, the vessel has been up and running for six months. After more than 1,000 hours of running the pumps, the client is satisfied with the performance of the dredge and the pumps. A successful project of this size and scope is a testament to the expertise and value that GIW provides, crossing international barriers to ensure a customer’s success.