It is no secret fouling is a huge issue faced by the oil and gas industry. Heavily fouled assets affect refinery profit, the environment and operator safety, which in turn affect most plant personnel, financial stakeholders, governing bodies, regulators and a plethora of people in between.
The issue of fouling is something to which one company has dedicated more than 30 years by researching and developing solutions to achieve better results than traditional fouling removal methods.
Tube Tech International is globally renowned as a research-led innovator in downstream fouling removal. Tube Tech provides simultaneous cleaning and inspection services for static heat transfer equipment that have delivered savings from $100,000 a year per exchanger to project savings of millions of dollars. With the cost advantages, reductions in downtime and CO2 emissions, as well as improved safety standards, it comes as no surprise the company’s unrivaled robotic, remote and in-situ services have been noticed across the U.S. Gulf Coast market, with the company having conducted business from its site in Houston for more than a year now.
Tube Tech has completed hundreds of cleaning and inspection jobs during planned and unplanned shutdowns across the world. There are several common fouling issues that, if left to worsen, can cause extensive process disruptions:
1. Fired heater convection cleaning. Fired heaters, furnaces or charge heaters cannot operate effectively when fouled, resulting in poor convection bank performance, increased stack temperatures and greater energy consumption.
Current cleaning techniques generally rely on a long, hollow lance being fed through side access doors to deliver the cleaning medium — e.g., air, water jets, dry ice or chemicals. However, these can only clean what the operator can see or reach. This means only the top surface or underside of a single finned tube row is cleaned, representing barely 2 percent of the entire 2,500-square-meter surface area.
2. Texas Tower Vertical Combined Feed Exchanger (VCFE) cleaning. The VCFE is one of a few heat transfer assets that often falls into the “out of sight, out of mind” category but, due to its criticality, requires cleaning every four years, especially when refineries expand or when there has been process carryover such as catalyst or oil. Challenges faced by those cleaning VCFEs/Texas Towers include fouling location, unknown fouling characteristics, accessibility, safety, and associated costs and risks with pulling. It is important to use a contractor that guarantees they are cleaned on both sides (not just the tube side) and has the know-how to clean them in-situ or, if needed, to pull these mammoth heat exchangers quickly and safely.
3. Cleaning for internal rotary inspection system (IRIS) inspection. Many refinery operators and maintenance personnel will be familiar with the following scenarios:
• Cleaning contractor “cleans” heat exchanger ready for IRIS inspection.
• IRIS inspector is unable to inspect due to tubes not being clean enough.
• Cleaning contractor is called back to “re-clean” tubes to a higher standard.
• IRIS inspector is recalled to re-inspect tubes.
These scenarios are happening time and time again in refineries across the world, and the financial impact is not only the cost of the cleaning contractor and the inspection company but also the additional downtime incurred.
4. Twisted Tube™ Heat Exchanger cleaning. Increasing in popularity, Twisted Tube Heat Exchangers by Koch Heat Transfer Co. provide a higher heat transfer than many other types of tubular heat exchangers; however, they can be a challenge for traditional cleaning contractors. Both shell- and tube-side fouling on Twisted Tube Heat Exchangers is often seen as difficult to remove using either traditional high-pressure water jetting or chemicals.
5. External shell-side heat exchanger cleaning. Removing process deposits where access is limited is a huge challenge for all refinery and petrochemical sectors, especially where fouling reduces heat transfer and production throughput.
Maintenance professionals and jetting contractors alike focus on removing deposits from inside the straight heat exchanger tube bores. Why? Simply because the external shell-side tube surface of heat shell and tube exchangers is invariably inaccessible and therefore cannot be cleaned using traditional bundle blasting methods. Tube Tech recommends clients weigh their heat exchangers before and after cleaning. Anything over design weight “after cleaning” means fouling has not been removed and therefore energy and production losses will continue as the asset life continues to depreciate.
1. Next-generation cleaning robot. In 2019, Tube Tech International launched its next-generation fouling removal robot. The technology, developed as a result of an extensive R&D program, is capable of eradicating more than 90 percent of heat exchanger fouling.
A defining feature of the new robot is the system’s ability to record videos and images of blockages, concerns and the cleaning taking place while automatically adjusting to warped tubes.
The robot can be programmed with information supplied by the client, creating a visual representation of the bundle for Tube Tech technicians to utilize before gaining access to the site. This information is used to select the best cleaning process, which can be pre-programmed into the robot, saving valuable time on-site.
“We introduced the technology at Syngas 2019 in Houston in March,” said Managing Director Jon Camp. “The feedback was overwhelmingly positive. It is packed full of proven technology we have spent years developing; the idea was to clean faster, safer and sustainably whilst achieving superior results. I feel that we have achieved these goals with this technology.
“This technology was developed due to the ineffectiveness of current cleaning methods. Traditional water jetting can damage costly assets; it uses 25-percent more water than necessary and only cleans between 30-50 percent of fouling. Our next-generation robot protects assets, drastically reduces water consumption and eradicates more than 90 percent of fouling.”
2. Shell Side Jet™. In 2018, Tube Tech received Horizon 2020 SME Instruments funding to develop the next generation of its patented Shell Side Jet solution, which will deliver the first-ever technology guaranteed to remove fouling from the outside heat transfer surface of shell and tube exchangers.
The Horizon 2020 SME Instrument is a public funding program that advances market-creating innovation in disruptive small businesses with significant growth potential and global ambitions.
As part of the program’s goal to radically reduce carbon emissions and achieve climate resilience by the second half of this century, Tube Tech’s Shell Side Jet solution was granted funding in recognition of the benefits it can bring to the performance of the petrochemical industry and its environmental responsibility.
“We have created Shell Side Jet to tackle one of the most common fouling issues,” Vice President Christian Chanel said. “Traditional methods have often come up short when it comes to removing heavy fouling from the outside heat transfer surface of shell and tube exchangers. With this new technology, which will be available in February 2020, our clients will have access to the most innovative cleaning technology available, saving millions of dollars by achieving a far superior clean.”
Fouling is a serious problem that should be dealt with proactively and as part of a planned maintenance program. Awareness of common fouling issues is key to understanding which assets require regular cleaning and inspection services. If they’re maintained to a high standard, optimum thermal efficiency can be achieved, generating a dramatic increase in profits and a decrease in CO2 emissions.
Tube Tech is an industry leader in cleaning and inspection services, having dedicated more than 30 years to researching and developing innovative solutions to the most serious fouling issues. Fouling is a problem, but Tube Tech has the solutions.
For more information, visit www.tubetech.com/usa, call (832) 286-1322 or email info@tubetech.com.
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