Omega installs a Mobile Drier at Sheffield Forgemasters
Sheffield Forgemasters International Ltd. reported it is the first foundry in the U.K. to adopt a state-of-the-art mold and core coating technology, improving the quality its large, high-integrity castings and establishing more efficient production processes. SFIL is a multi-faceted engineering group with specialties in several critical energy markets, including nuclear power plants and offshore drilling platforms.
The SFIL manufacturing complex at Sheffield, England, includes electric furnace melting and casting for ingots, foundry and forging operations, as well as large-dimension machining capabilities.
The 10,000-metric tons/year foundry pours ladles of carbon or stainless steel up 100 metric tons, for products with maximum dimensions of 16X7.6X4.6 meters. It is able to produce castings weighing up to 350 metric tons, and engineering, patternmaking, ultrasonic testing, and heat-treatment of finished products are done on site.
Forgemasters’ new mold and core coating process is a two-part system consisting of two computer-controlled coating preparation plants, that deliver water-based zircon slurry coatings with consistent viscosity and density; and a dedicated core and mold drying oven, supplied by Omega Foundry Machinery Ltd to control the drying of the coating.
The new process allows Forgemasters to apply coatings of uniform composition and thickness to its molds, used to form large, complex steel castings, which reduces preparation time, improves casting surface finish, and makes it easier to remove refractory from the casting.
Previously, SFIL used a manual preparation and coating method which led to inconsistency’s in coating quality and thickness.
The temperature-controlled slurry is automatically diluted and tested, and then pumped to an application nozzle for the operator to direct over the sand mold. The uniform composition and density ensures that the cores and molds are “flow coated,” which achieves a constant and accurate layer thickness.
SFIL is conducting trials now to develop a spray application, for use on large molds or core sections that cannot be directly flow-coated.
After the coating is done, the new system’s mobile oven reduces drying time for coatings from several days to just four hours, from start to finish. The rail-mounted, gas-fired oven is able to service four separate areas, each one measuring 4 metres x 4 metres where items are placed, ready for drying.