Back to Refineries (Onshore - Downstream) Case Studies Print this page

Heat Exchanger – In-Situ Cleaning of Aluminium U-Tubes in Furfural Heat Exchanger

Blockage removal increased from ca. 20 to 90 percent

Summary

A radical new approach to cleaning notoriously tenacious scale within aluminium U-tubed furfural exchangers introduced substantial benefits at a UK refinery. Blockage removal from the U-tubes was increased from ca. 20 to 90 per cent, potential damage to aluminium tubes eliminated and the exchanger was cleaned in-situ. Downtime was reduced by three days which in turn reduced costs and improved performance.

Challenge

To avoid damaging the delicate aluminium tubed furfural exchanger, previous cleaning attempts had been restricted to 200 bar water pressure ((3,625 psi approx).
The conventional water jetting process only managed to remove 20 per cent of blockages and scale on the straight legs alone.

Solution

Tube Tech’s R&D team developed a system which removes tenacious coke deposits with a combined pressure and mechanical device upping pressure to 2500 bar (40,000 psi approx). This achieved 90 per cent coke removal from all sections of the U-tubes including the bends.
The radically-different three-stage process involved a sensitive mechanical hairpin cleaning device coupled with exceptionally low volumes of water.
Each tube was cleaned using a patented Softdrill lance made from “intelligent” metals to prevent damage to the tube wall.
A Tube Tech-developed micro turbine rotating under controlled hydraulic pressure was guided through each tube.
Another Tube Tech innovation enabled cleaning in-situ for the first time, reducing down time by three days and eliminating the cost of craneage and heat exchanger pulling equipment.

Client Comment

The TIPS Planning Team leader at BP said: “Tube Tech’s specialist capabilities are excellent. This particular type of coke deposit is very stubborn stuff to remove. A traditional 200 bar pressure had limited success on the straights and tended to compact rather than remove fouling on the U-bends.

Tube Tech took sample tubes away and then demonstrated their solutions with digitally recorded evidence. By not having to remove the tube bundle from its shell we reduced equipment downtime by about half.

The fact that we were able to achieve a very high standard of cleanliness was a true testament to Tube Tech’s abilities. Also, not having to disturb the heat exchanger will lengthen its life, and from the higher standard of cleanliness reached we would expect to see longer periods between cleaning. We have not yet been able to calculate the site production benefits but they are expected to be significant.”

Clients can be contacted via Tube Tech for references.

Back to

Refineries (Onshore - Downstream) Case Studies

Related Case Studies

Techniques Used