Troubleshooting and Improving Operation of a Main Fractionating Tower

Following a refinery turnaround the Main Fractionator in the Ultra-low Sulphur Diesel unit was field tested and studied for its root cause of flooding. Gamma scans indentified two sources of flooding originating from a pair of draw downcomers. Neutron backscatter technique was used to investigate and confirm downcomer hydraulics to identify the root-cause of flooding in the Fractionator. The downcomer design was studied and determined to be conducive for plugging and flooding. A simpler downcomer design was proposed and implemented renovating a complicated piece of hardware that was conducive to plugging.