Golden Bridge Welding — Existing Line Upgrade & Capacity Expansion to 36,000 TPY

Client Background

Golden Bridge Welding is headquartered in Tianjin, China, and ranks among the country's largest producers of welding consumables. Its product portfolio covers submerged arc welding (SAW) flux, covered electrodes, and solid wires, supplying shipyards, pipeline contractors, and structural steel fabricators across domestic and export markets. By the late 2010s, the company was operating several flux production lines built around agglomerated technology. While these lines had delivered decades of reliable service, the global market was shifting toward sintered fluxes, which offer lower hydrogen levels, more consistent chemistry, and better suitability for demanding offshore and pressure-vessel applications.

The Challenge

The existing agglomerated line at Golden Bridge Welding's Tianjin plant had three core problems. First, the furnace section was reaching end of life, with rising maintenance frequency and increasing temperature inconsistency. Second, the installed capacity was no longer enough to support the company's export growth and domestic demand for high-quality sintered flux. Third, the client wanted to avoid a full greenfield project because a complete demolition would interrupt production, consume additional land, and require extensive re-permitting. The target was clear: convert the agglomerated line to sintered production and expand output to 36,000 tonnes per year, while keeping civil works, material handling, and utilities largely intact.

FUMI Solution

FUMI Consulting began with a detailed audit of the existing plant, mapping the agglomeration kiln, dryer, screening tower, packaging stations, and dust collection system. The engineering team then proposed a retrofit strategy rather than a full rebuild.

• 310S sintering kiln: A new high-temperature kiln was installed in the footprint of the old agglomeration furnace, using 310S-grade stainless steel internals to withstand the 1,200–1,300 °C sintering zone.
• Drum granulator: A purpose-built drum granulator was added to produce uniform green granules before sintering, replacing the older pan-type agglomeration unit.
• Infrastructure reuse: Existing raw-material silos, batching systems, cooling conveyors, and bagging lines were retained and integrated with the new equipment through custom PLC controls.
• Process controls: Temperature profiles, retention time, and gas-to-material ratios were automated and linked to the central SCADA system for consistent quality.

The upgrade was executed in two phases to keep at least one production stream running during the cutover, minimising lost output.

Before vs. After

Key Results

Within six months of commissioning, the upgraded line reached its design capacity of 36,000 tonnes per year. Quality testing showed improved moisture resistance, lower hydrogen potential, and more uniform particle size distribution — key requirements for offshore and high-strength steel applications. Energy consumption per tonne of finished flux fell by more than 25%, driven by the efficient kiln insulation, better burner control, and the optimised sintering curve. The client was also able to introduce new sintered flux grades for pipeline and shipbuilding customers without building an entirely new facility.