Nonlinear Creep Analysis - Furnace Coil Case Study

Problem

A major ethylene producer was concerned about potential long term problems with support and creep of the furnace coils of a new cracking furnace design. The client hired KHE to develop non-linear creep finite element analysis of the coils.

Solution

KHE performed a comprehensive nonlinear finite element model of the furnace coil system with supports. Creep equations for the material were incorporated into the analysis. The analysis determined overstress problems after relaxation of the coils and load transformations. These problems lead to excess bowing and buckling of the coils. KHE changed the design based on the model.

Results

The facility implemented the design. The model was verified by measuring deflections in the cracking furnace after a period of time in operation. The ethylene producer avoided shutdowns and repairs by taking care of this problem before it could occur.