Thermal Analysis of the Molten Lead KettleFailure at the Galvanizing Plant and Developmentof Novel Design Using CFD Techniques

Abstract

The present work discusses problem of failure of kettle holding molten lead in a galvanizing plant. A CFD code Fluent was used to solve the problem using computational approach. The geometry is built in the GAMBIT environment and 3D solvers for turbulence, combustion and radiation heat transfer was applied. The study revealed the detection of the hot spot exactly at the same location of the kettle that was observed at the plant. This confirms the validity of the CFD Model. Based on this model the suggestions are made to overcome kettle bulging. For this two approaches are suggested. They are, differential heating of the kettle and the reduction in the width of the burner. The effect of both these alternatives is studied using a CFD model and the effectiveness of the results are discussed and compared using dimensionless surface parameter representing the temperature distribution and flue gas temperature. Based on the results obtained an improvised geometry for the kettle heating is proposed. The proposed novel design has the following features:  50% reduction in the fuel consumption and lower start-up time.  Separation of the zone of mechanical and thermal stresses and lower concentration of thermal stresses.  Increase in the heat transfer area and a reduction in the heat losses through the exhaust.  Reduction in the amount of lead used for the operation.The present work discusses problem of failure of kettle holding molten lead in a galvanizing plant. A CFD code Fluent was used to solve the problem using computational approach. The geometry is built in the GAMBIT environment and 3D solvers for turbulence, combustion and radiation heat transfer was applied. The study revealed the detection of the hot spot exactly at the same location of the kettle that was observed at the plant. This confirms the validity of the CFD Model. Based on this model the suggestions are made to overcome kettle bulging. For this two approaches are suggested. They are, differential heating of the kettle and the reduction in the width of the burner. The effect of both these alternatives is studied using a CFD model and the effectiveness of the results are discussed and compared using dimensionless surface parameter representing the temperature distribution and flue gas temperature. Based on the results obtained an improvised geometry for the kettle heating is proposed. The proposed novel design has the following features:  50% reduction in the fuel consumption and lower start-up time.  Separation of the zone of mechanical and thermal stresses and lower concentration of thermal stresses.  Increase in the heat transfer area and a reduction in the heat losses through the exhaust.  Reduction in the amount of lead used for the operation.