An infra-red automation system for billet discharge from caster to cooling bed at Durgapur Steel Plant, SAIL

摘要

Since the installation of infra-red sensors to replace mechanical switches which frequently failed to control the billet discharge mechanism from the caster, caster down-time and return of heats due to unavailability of the caster has been reduced to zero. THE continuous casting shop of Durgapur Steel Plant (DSP) has two billet casters which were provided with electro-mechanical limit switches to detect billets at pre-determined physical locations to slow down and final arrest the pusher rams that manipulate the billet from the caster to the cooling bed. The arrangement of the mechanical limit switches is shown in Fig 1. These electro-mechanical limit switches operate when the leading billet, which is at red heat, hits the arm of the limit switch. Due to the repeated mechanical impact of the arm by hot billets it tends to fail which breaks the drive chain of the ram and stops billet discharge and so causes an accumulation of billets resulting in the need to stop casting and therefore the need to return the running ladle back to the steelshop.