“Impossible” Polymer Shell Side Fouling of Exchanger Cleaned To Bare Metal

Unique cleaning technique removes polymer from between tubes

Summary

Severe raw polyethylene fouling on the Shell side of several reactor condensers within a Middle East petrochemical plant was causing increasing concern to the plants operators.

This fouling issue is leading to the plant requiring taking one or more reactor condensers out for cleaning every four weeks resulting in reduced production. The plant operators needed to find a solution and quickly.

Problem

The plant produces 1 million tons of Ethylene and 400, 000 tons of high density Polyethylene each year. The shell side fouling on the reactor tubes was like having a 1m cube solid block of high density polymer surrounding the stainless steel tube external surfaces.

The client urgently required passage between the tubes. The biggest challenge to any contractor was not only removing the polymer deposit from the external tube surfaces but also to overcome the most difficult problem of “access between the 5mm gap between the tubes” in order to get access and clean the polymer. Traditional high pressure water jetting and band saws could only create a gap the width of the saw blade and nothing more.

Solution

Having recently returned from a successful “tube and shell side” clean of a VCFE (20 metre long Texas Tower) in France the Tube Tech team believed that with design modifications this cleaning system would be a basis to apply this in the Middle East.

The bundles were positioned in the cleaning bay to allow access for their bespoke Plate JeTT™ and SafeSeal™ systems. Tube Tech removed 95% of the polymer fouling from the shell side compared to 20% from others using bespoke manufactured equipment (under license) to access between the 5mm tube gap ensuring 360 degree tube surface coverage was achieved. The process was applied using semi remote equipment to minimise the fatigue element making the cleaning process far safer and therefore quicker.

As can be seen from the images Tube Tech’s unique technology was able to remove the fouling effectively with no damage to the shell or tubes.

Tube Tech comment

"Once again Tube Tech were presented with a seemingly impossible challenge and through innovative technology and safe working practises a solution was found.

I am certain that the fast and safe removal of tenacious fouling from the “shell side” of shell and tube exchangers will come as welcome news to many industries worldwide", said Mike Watson, Technical and Managing Director at Tube Tech

For more information or to discuss your cleaning challenge call us on +44 1268 786999 or e-mail info@tubetech.com, alternatively click here to fill out our contact form.