Ladle furnace on-line reckoner for prediction and control of steel temperature and composition

Abstract

In the present day competitive market scenario, steel producers are striving for high speed continuous casting with stringent and consistent quality as well as reduced production cost. The ladle furnace (LF) is a key unit for achieving the above objectives during secondary steelmaking. Proper control of process parameters during LF processing of liquid steel is essential. The paper reports development of a model based advisory system, called ladle furnace on-line reckoner (LFOR), for the prediction and control of temperature and composition of steel in a LF. The thermal and chemistry models employed in the LFOR system are based on simplified physics, material and heat balance, and statistical analysis of plant data. The LFOR system is provided with graphical user interface (GUI) to display the predicted composition and temperature profile. The control advice displayed on the screen provides guidance for arcing and addition to achieve the target temperature and composition. The LFOR system has been commissioned at LF No. 2 of the LD2 and Slab Caster Shop of Tata Steel, Jamshedpur and is designed to meet the requirements of sequence casting as well as to optimise the energy input and cost of alloying additions. The performance of the LFOR system was analysed and validated with data taken over 100 heats and was noted to be satisfactory.

Keywords:

• LADLE FURNACE ON-LINE RECKONER (LFOR)
• ADVISORY CONTROL SYSTEM
• SUPERHEAT CONTROL
• COMPOSITION CONTROL
• SOFT SENSOR
• GRAPHICAL USER INTERFACE(GUI)
• MULTIVARIABLE STATISTICAL ANALYSIS
• MODEL BASED PROCESS CONTROL (MPC)