Steel is the most common alloy in the world and consists of iron with varying amounts carbon. It is widely used in construction and other applications because of its high tensile strengths and low costs.
Although steel had been produced in furnaces for thousands of years, steel’s use expanded extensively after more efficient production methods were devised in the 17th century for blister steel and then crucible steel. With the invention of the Bessemer process in the mid-19th century, a new era of mass-produced steel began. This was followed by Siemens-Martin process and then Gilchrist-Thomas process that refined the quality of steel.
Further refinements in the process, such as basic oxygen steelmaking (BOS), largely replaced earlier methods by further lowering the cost of production and increasing the quality of the metal. Today, steel is one of the most common materials in the world, with more than 1.3 billion tons being produced annually. It is a major component in buildings, infrastructure, tools, ships, vehicles, machines, appliances, and weapons.
The first section in the cycle of steel production is the Blast Furnace. The iron furnace itself is built in the form of a tall structure, lined with refractory brick, and profiled to allow for expansion of the charged materials as they heat during their descent, and subsequent reduction in size as melting starts to occur. Coke, limestone flux, and iron ore (iron oxide) are charged into the top of the furnace in a precise filling order. “Uptakes” allow the hot, dirty gas high in carbon monoxide content to exit the furnace throat, while “bleeder valves” protect the top of the furnace from sudden gas pressure surges. The coarse particles in the exhaust gas settle in the “dust catcher”, while the gas itself flows through a venturi scrubber and/or electrostatic precipitators and a gas cooler to reduce the temperature of the cleaned gas.
The “casthouse” at the bottom half of the furnace contains the bustle main, water cooled tuyeres and the equipment for casting the liquid iron and slag.
In January 2012 Ledwood were awarded a contract by Tata Steel for the Procurement, Fabrication and Installation of the Furnace Cooling Water System for the replacement of the No. 4 Blast Furnace at their work in Port Talbot South Wales.
The project was scheduled in two phases:
- Phase 1 – Jan 12 to Jul 12 : Fabrication & Module Fit Out of the 4 main Furnace Tower Modules
- Phase 2 Sept 12 to Nov 12 : Complete interconnection pipework between modules, install copper stitch pipe assemblies to for the plate and tuyere coolers and install drop legs from module pipework to stitch pipework
The scope included the procurement, fabrication, painting and installation of over 25,000m and the procurement and installation of over 5000 manual valves. By the conclusion of the project cira 3500 isometrics had gone through the fabrication facility and were subsequently installed on site.
In addition to the original contract there was a large element of scope growth, which included design and engineering, and at its peak the number of the Ledwood indirect and direct employees were in excess of 200 on site.
As a company we faced a number of challenges in the execution of the project, which included, working with a new client on an unfamiliar site, aggressive schedule, large scale procurement, one of the largest pipework projects to go through the shops in recent times, historically poor site safety record and dependencies on Main Contractor’s Programme.Back to sectors