Structural Dynamics of Furnace Coil Case Study

Problem

A major refinery was experiencing vibration problems with a high temperature furnace coil used in a cracking process. The flow-induced vibration shook the coil and failures were experienced. Differential thermal growth and the need for heavy constraint caused conflicting design issues. KHE was contracted to design the coil to handle the driving forces of the flow and to allow for the thermal expansion.

Solution

KHE developed a structural dynamics model of the coil using the CAESAR II pipe stress tool. With custom software, KHE determined the driving forces from the flow induced vibration. Strategically placed supports reduced harmful dynamic effects and allowed for differential thermal growth.

Results

The design was implemented and the furnace performed as designed.