Crude Train U-Tubes Polished in Five Hours

Energy efficiency increases three-fold

As a company which has built its considerable reputation on innovation, Tube Tech is constantly reviewing fouling removal methods. When new processes and practices are refined at Tube Tech, they are recommended to client companies for future implementation. This was the case with the restoration of two crude oil heat exchangers at an oil refinery in Essex, U.K.

The Challenge

One of the most crucial fouling removal operations at a refinery is the crude oil heat exchanger train involving considerable and potentially expensive downtime when taken offline.
Reducing downtime can save hundreds of thousands of pounds.
The most common forms of maintenance methods employed by competitors have been chemicals or traditional high-pressure water jetting each taking an average of three to seven days respectively.
Neither process consistently achieves the optimum removal of tenacious carbon and coke deposits that form within the “U” bends nor the straight tubes.
Chemicals cannot negotiate the blockages often found in crude exchangers plus the environmental, waste issue is always present.
High-pressure jetting can be slow, or lances can become bent if confronted with blockages.
Moreover, flexible and rigid high-pressure water lances never negotiate the hairpin bends.

The Solution

This involved a new three-stage process which starts with a Rotaflex Softdrill being fed down the tubes using a bespoke lance feeding mechanism.
This was followed by a rigid lancing system utilising intelligent metals that reform to its original state after negotiating the bends.
Finally, the rotary turbine darTT is utilised to rotate down the tubes, scouring and polishing the internal bore.
A special mock-up was built for the client at Tube Tech’s headquarters to prove the three-stage process would be effective.
The rotating turbines were adapted to negotiate bends without jamming.
The hairpins were restored back to bare metal, indicated by the gingering up of the carbon steel tube surface.
Downtime was reduced to an incredible five hours.
The effect of such an efficient project was more than $1 million in fuel savings through a reduction of furnace inlet temperature of 12C.
After restoring just one hairpin exchanger and polishing the bends Tube Tech methods increased their energy efficiencies almost 3-fold up from 150,000 when using traditional chemical and pressure jetting systems to a massive 400,000 kJ/C-HR.

Tube Tech Comment

Scott Donson, Technical Director: “Our philosophy to challenge tradition far exceeded our clients and to be frank even our own expectations. The ‘horses for courses’ approach is key to establishing better results backed by our on-site experience. This achieved yet another landmark in cost saving exercises targeted at refinery downtime and production performance.”

Is your facility suffering from reduced output? Contact our team today for a free technical evaluation to begin your journey to heat transfer recovery.