In July 2013, Steloy delivered four stainless steel rotating grate castings from energy and chemicals group, Sasol. Steloy was awarded the contract by MTP after working with them on a similar project utilising Lurgi FBDB gasification technology to produce direct reduced iron in an Indian steel making plant.
The core components of this process are the gasifiers in which coal is converted to syngas by means of partial oxidation with steam and oxygen. Although similar to the Lurgi version of the technology destined for India, these gasifiers represent Sasol’s own, independent proprietary embodiment of this technology developed with the benefit of more than five decades of operational experience.
Steloy already had a track record in the successful delivery of castings for Sasol, and their experience and capacity to execute a contract of this nature and size are some of the reasons why Steloy was chosen as the foundry partner on this contract. Casting of the main grate components takes place at Steloy’s Chamdor facility, which is able to accommodate the manufacture of components up to 3.5 tons.
Manufacturing the casting for the bottom gear of the gasifier represented the greatest challenge, owing to the gear comprising two equal pieces of heavy section and the high-integrity materials used to manufacture the unit needing to undergo induction hardening afterwards.
“Casting gears is challenging to start with, but when a gear is going to be used in this kind of environment and adhere to very strict quality standards, the challenges increase,” he adds.