Nov-2021

Convection section retrofit (TiA)

XRG recently retrofitted a convection section in a crude heater that was originally built in 1935. The new convection bank consists of two sections; the lower half is used to preheat the crude while the upper section is used to generate superheated steam.

XRG Technologies

Article Summary

Currently, the site is processing crudes that are heavier than the original design crude. As a result, process data shows the absorbed duty is 33% lower than the furnace was originally designed for. To meet the customer’s needs, the furnace also needs to produce 8-11 t/h of steam. To meet that requirement, the furnace is operated at high excess air, with flue gas oxygen content typically ranging between 6% and 8% by volume (wet), which is bad for fuel efficiency. The current efficiency varies between 82% and 85%, substantially less than the design 88.5%.

For the solution, XRG completed an engineering study which proved that the convection section needed to be replaced to meet the customer’s needs. Subsequently XRG provided CFD, full engineering, design, and supply of an auxiliary convection section module complete with soot blowers and upgraded steam coil material for installation in the existing convection section.

The new convection module met the customer’s requirements of fuel efficiency, absorbed duty, steam production, and replaced existing steam coils with a higher heat resistance material to prevent partial tube replacements at every turnaround.

This short case study originally appeared in PTQ's Technology In Action Feature - Q4 2021 Issue.

For more information: Info@xrgtechnologies.com