Top 10 Cleaning and Inspection Challenges: No. 9
Steam Cracking Furnace Cleaning
Based on an extensive survey of 500 refinery operators, steam cracking furnace cleaning ranks ninth among the most prevalent cleaning challenges. In this in-depth discussion, we will explore the issues around ethylene furnace fouling and solutions to restore efficiency and maximise productivity.
Steam crackers, also known as Pyrolysis furnaces, are used to produce Ethylene. They require proper maintenance for long-term, safe, and reliable operation. The convection section, prone to external fouling, needs critical maintenance for optimal performance. However, cleaning pyrolysis furnaces can be challenging due to limited accessibility. Tube Tech provides a solution with a self-propelled robotic cleaning vehicle, which effectively removes stubborn fouling from every row of tubes.
The use of robotic convection section technology enables thorough cleaning of all tube rows, despite even the toughest deposits. This remotely operated technique offers a safe, fast, and effective solution for operators worldwide.
Ethylene, the most produced organic compound, is a vital component of many industries, with numerous companies across different countries involved in its production. With global ethylene production on the rise, efficiency improvement and energy cost reduction are constant priorities for ethylene producers. Enhancing the efficiency of ethylene cracking furnaces, particularly through improved cleaning techniques in the convection section, can lead to significant savings for operators.
Challenge
Furnace convection coils are not the primary focus of furnace designers, as their main goal is achieving optimal performance. However, cleaning the coils poses a logistical challenge due to the tight arrangement of tube banks. While some furnace convection sections have large inspection and coil removal doors, others require openings to be cut for maintenance purposes.
The inaccessibility of surface areas within deep tube banks often limits cleaning efforts to visible areas only. Additionally, accessibility may be hindered by masking from front and secondary rows of tubes. It has been traditionally accepted by operators that a 50% reduction in fouling factor constitutes a “clean” condition for furnaces that have been operational for more than five years.
Solution
Tube Tech offers specialized robotic cleaning technology for steam cracker convection sections. The robotic system efficiently cleans both square and triangular pitch rows of convection tubes, resulting in significantly improved cleanliness compared to traditional cleaning methods such as chemical cleaning, hydro blasting, abrasive shot blasting, soot blowers, and CO2 dry ice blasting. The robots are specially designed to minimize the amount of access points to be cut in a convection section. After placing on the top of the tube bank, they can move along and across the tubes, and overcome the support plates.
The technology can be quickly adapted to access the furnace through inspection/viewing doors. With approximately 98% surface contact, the robot can effectively remove severe fouling from the entire convection section and clean a 60 ft long section in just 4-5 shifts. Moreover, this cleaning method ensures no damage to the refractory, and the service includes comprehensive before, during, and after inspection reports.
Conclusion
To summarize, successful completion of convection section cleaning results in increasing convection section efficiency and returning its operation to design. Eliminating fouling from within pyrolysis furnace convection sections can significantly enhance the furnace’s reliability and extend its asset life. Emphasizing regular cleaning and maintenance can ensure optimal performance and efficiency for this critical equipment.