Heat Exchanger Cleaning

Altrad was contracted by a major UK-based operator tocomplete specialist cleaning works on six heat exchangers which were operatingat reduced capacity on an offshore asset in the Irish Sea. Upon investigationof the tube bundles, it was noted the external shell was clogged withsolidified scales and the tubes had partial blockages due to wax and scalebuild up, which ultimately led to an impact on production.

Tube bundles explained: Tube bundles are locatedinside shell and tube heat exchangers. The tube bundles are positioned within acylindrical shell, where fluids at different starting temperatures (eitherliquids or gases) pass through and over tubes.

Conventional retro-jetting didn’t provide the desired end result.Therefore, Altrad’s team of experts re-assessed the scope and altered themethodology to tackle the challenge. This ultimately ensured our client’sexpectations were met. The deployment of specially selected jets were utilised toremove the hard scale. A jet centraliser was used to protect the jet as itpassed through the vessel internal shell, centralising the jet extension armsto a stand-off distance for a more consistent clean.

A 3-man multi-discipline team was mobilised to execute this scopeof work. Through use of bespoke jetting techniques, the team cleared the tubebundles and shell of scale and debris to allow for an Internal RotaryInspection System (IRIS) inspection to take place.