Author: Mike Watson, Managing Director, Tube Tech

Following a recent survey of refinery operators from across the world Tube Tech have compiled the Top 10 cleaning and inspection challenges faced by the refining industry.

As a world leading specialist industrial cleaning contractor Tube Tech have solved some of the refining and petrochemical sectors most difficult cleaning challenges. Tube Tech asked over 2500 refinery operators to complete their survey and the Top 10 cleaning and inspection challenges were developed as result of the survey feedback.

Below is the 2nd most common cleaning and inspection challenge faced by the refining sector.

No 2     Texas Tower / CCR Platformer / VCFE (Vertical Combined Feed Exchanger) Cleaning

At the heart of many refineries the VCFE (vertical combined feed exchanger commonly known as a Texas Tower), is located on the CCR Platformer unit. Originally designed with a small footprint and not expected to foul this colossus of a shell and tube exchanger is now centre stage when it comes to recovering MWatt and productivity and very much on the critical path during a shutdown.

The very fact these gigantic shell and tube heat exchangers were never expected to foul means that accessibility and clean-ability didn’t figure highly at design stage. As a result specialist technology is now required to clean both tube and shell side thoroughly never more so when integrity of the asset is needed. If the asset cannot be cleaned sufficiently for eddy current or IRIS tube inspection then this, like any heat exchanger, has a serious financial impact on the refinery’s bottom line.

Tube Tech is the only company with an extensive suite of technologies and methods to clean and inspect all shell and tube Texas Towers as well as other floating head and welded exchangers in a fraction of the time compared to traditional high pressure water blasting it chemical methods.

Challenge

Reactor outlet and heater inlet temperatures will often be the first sign that the shell and tube side of a Texas Tower needs cleaning.

Unblocking and cleaning the unusually small tube diameter of 12mm, combined with a 20m+ vertical tube length is often the first challenge for high pressure water jetting and chemical cleaning contractors alike.

Secondly and most challenging is negotiating the external, shell side to remove tube surface fouling that sits deep inside the bundle where the only access is between the 5mm tube spaces.

Chemical cleaning invariably compounds the fouling when moderate to heavy fouling is present. Any pumped fluids simply lack the shear force needed to negotiate and flush the dense and often inert mix of hydrocarbons, coke, iron oxide and gum formation down and through the high number of baffle plates.

In order to overcome all these issues, access is achieved by delivering a bespoke and engineered cleaning and inspection solution.

Solution

Tube Tech are able to provide a seamless tube and shell side cleaning service which ensures VCFE’s are brought back to production standard using the following tube cleaning and shell side cleaning techniques and technologies.

Tube Side

  • Pulse jets and robotic acoustic sensors used to locate and unblock soft tube blockages,
  •   Severe tube blockage removal is done quickly with multiple safedrill units.
  •   Rapid  Rotary turbine, tube cleaning darTTs™ are used for tube descaling

Shell Side

  •           Tube Tech’s rotary ShellJeTT™ is the only system to slide In between the 5mm tube space using dense water jets, rotary agitation and ultrasound to remove the majority of shell side fouling no matter how severe.

Conclusion

The VCFE is one of a few clean duty exchangers that often fall into the “out of sight, out of mind” category but due to their criticality will require cleaning every 4 years especially when refineries expand or when there has been process carry-over such as catalyst or oil. When it does come time to clean these significant assets it is important to ensure you use a contractor that guarantees they are cleaned on both sides not just the tube side and the know how to clean them in-situ or if needed to pull these mammoth heat exchangers quickly and safely. With the ability to clean both the shell and the tube side of the most fouled VCFE’s, Tube Tech are proud to be recognised by leading refinery operators as the leading VCFE cleaning authority. As a Netherlands based refinery client recently said; ““Asset integrity is crucial for refinery operators and we were pleased to receive an excellent service in the timescales specified.”