K. Boshnakov, M. Hadjiski. Risk Including in the Task of Predictive Maintenance of Copper Converter

Key Words: Risk including; copper converter; predictive maintenance; case-based reasoning; rulebased reasoning; decision support.

Abstract. The purpose of the investigation is increasing the Remaining Useful Life (RUL) of Peirce-Smith (PS) copper converters on the base of risk assessment. During the operation, on the time of the last third of the cycles in the convertor campaign, there is a danger of a breakthrough in the tuyeres. An approach for the current individual risk assessment of each one tuyere is adopted and on this basis the real risk assessment for the tuyeres line is determined. A two-step predictive maintenance procedure is proposed based on the value of the current breakthrough risk in the tuyeres. When risk assessment is under 80%, the main task is to align the profile of the tuyeres line, and supportive actions are limited to determining which tuyeres should be blocked or unblocked. When the risk rises above 80%, then move to another strategy, which takes into account four risk components: breakthrough in the tuyeres, breakthrough in the body of the converter, non-conventional composition of the black copper, and failure of the intended yield. Decision making for predictive maintenance in this case is supported by Case Based Reasoning and Rule Based Reasoning systems and technological actions and maintenance actions are proposed.