Large Diameter Metallic Duct Bellow Expansion Joints Successfully Supplied to a Copper Mining Project in Zambia
Executive Summary
Recently, large-diameter metallic duct bellow expansion joints manufactured by our company were successfully delivered overseas and deployed in a major copper mining and non-ferrous smelting expansion project in Zambia, Africa. This batch of heavy-duty duty expansion joints is specifically engineered for the high-temperature flue gas systems and large-scale ventilation pipe networks of the core smelting furnaces. Facing highly corrosive dust-laden flue gas, severe fan vibrations, and massive displacements caused by thermal expansion, our products have become the designated core components for this project due to their outstanding flexibility and corrosion resistance.
What Grim Challenges Does the Zambian Smelter Ducting System Face?
1.Thermal Expansion Caused by High Temperatures in Smelting:
The ductwork carries high-temperature waste gas or hot air from the smelting furnace. Drastic temperature fluctuations generate significant axial and lateral displacements. If not effectively absorbed, thermal expansion will directly lead to duct deformation, weld cracking, and even damage to connected equipment.
2. High Concentration of Abrasive Copper Dust and Ash Accumulation:
Smelting flue gas contains a large amount of high-hardness non-ferrous metal slag dust. High-speed gas flow causes severe erosion and wear on the pipe walls; when the flow rate slows, dust easily accumulates on the inner wall of the corrugated pipe, causing it to lose its elasticity.
3.Severe Acidic Corrosive Gases:
Copper smelting waste gas typically contains high concentrations of acidic gases such as sulfur dioxide. During system start-up, shutdown, or localized cooling, the gas easily forms acidic liquid on the inner wall of the pipes, corroding even ordinary corrugated pipes.
Our solution: Customized high-performance large-diameter duct metal compensators
To address these harsh ducting operating conditions, our engineering team bypassed conventional high-pressure piping designs and developed a tailored solution optimized for high-flow, low-pressure gas expansion joint environments:
1.Multi-Ply Stainless Steel Bellows Design to Effectively Absorb Thermal Displacement
Since duct walls are relatively thin, they cannot withstand excessive spring forces. We utilized an optimized multi-ply thin-wall SS316L bellows forming process. This design ensures absolute gas-tightness while drastically reducing the bellows spring rate (elastic stiffness), allowing the joint to flawlessly absorb the cold and hot displacements of the ductwork with minimal thrust.
2.Integrated Dust-Proof Internal Liners to Fully Resolve Slurry Erosion and Clogging
We configured a heavy-duty internal flow liner (sleeve) inside each metal expansion joint. Acting as a solid shield, this structure guides the high-temperature dust-laden flue gas smoothly through the pipeline. It prevents high-hardness particulates from directly scouring the flexible corrugated pipe and completely blocks internal dust accumulation, significantly extending the service life of the ductwork expansion joint.
3.Premium Corrosion-Resistant Alloys to Combat Acidic Fluid Attack
Targeting the unique acidic environment of the Zambian copper smelting system, the core material of the bellows underwent rigorous selection. Featuring exceptional resistance to acid corrosion, it effectively eliminates the risk of pipeline perforation and leakage.
Feedback photos taken by the customer after receiving the goods at the Zambian project site：
Looking for a High-Quality Duct Metallic Expansion Joint and Pipe fittings equipment manufacturer?
Since our establishment in 2006, Runtaida's products have been exported to more than 100 countries worldwide, earning an outstanding reputation in the global market. Our pipeline equipment is widely utilized in water conservancy, hydropower, petrochemicals, thermal power generation, and nuclear power projects. We provide comprehensive support ranging from technical selection to after-sales maintenance, ensuring zero-fault operation for your projects.
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