Furnaces / Fired Heater Convection Bank Cleaned Robotically on German Refinery
Furnace cleaned using remote mechanical operation
A German refinery requested Tube Tech to develop a robotic cleaning technology to clean deep in between both square and triangular pitch rows of convection tubes within their fired heater to improve on the poor cleanliness achieved using traditional water jetting and chemical service contractors. The “Remote Controlled Furnace Robot” was born, delivering an unprecedented level of cleanliness within record time. This included the removal of fused refractory that had cemented itself between the tubes over many years.
The client, like many fired heater users, had previously trialled many systems including chemicals, water jetting, abrasive shot blasting and even dry ice – all of which were limited in success mainly because blast methods only clean what the operator can see. Access deep inside and between the furnace rows was never achieved. Refractory damage has always been an issue when using conventional cleaning methods.
- The Remote Controlled Furnace Robot was built to access small 150mm x 200mm doors. These particular fired heater doors measured 500m x 500m.
- The contract duration was limited to only 48 hours to clean three levels on two fired heaters containing six convection banks x 15m long.
- The furnaces had not been cleaned properly for over 20 years. The heaters were being changed from oil to gas firing and it was important that the tubes were free from hydrocarbon fouling to ensure maximum heat transfer, reduced fuel consumption and asset life.
- No damage to the refractory was allowed and sulphuric acid vapour needed containing.
- The big advantage of the Furnace Robot is that it can remove extremely hard deposits deep within every tube row whether design is square or triangular pitch providing 360 degree tube surface contact as the fired heater is shut down and off-line.
- The unit inspects before, during and after cleaning. Multiple systems were used simultaneously. No refractory was damaged.
The client was quoted as saying ….“from my side thanks again for your work and smooth execution of the job. It is a considerable task to perform all the cleaning in only five days and with only a few weeks of preparations. Well done, very successful job!
What I can say is the stack temperatures of the furnaces dropped by 50°C in HVU2 and 80°C in CD2, which is a considerable increase in furnace / energy efficiency. We are talking about several Mega Watt of energy savings! Various out-of-the-box cleaning techniques and ideas from Tube Tech could certainly improve our performance, heat exchangers as well as furnaces.”
Tube Tech comment
Mike Watson, Managing Director: “This was challenging because our three R+D engineers were given only three weeks’ notice to build three multi-functional robots. This takes fired heater cleaning to a new level and overcomes all obstacles of limited access allowing robotic cleaning to be done via small and awkward access doors. The saving on fuel and CO2 emissions was substantial. Robotic cleaning of fired heaters will extend run times, reduce: tube distortion, replacement, fuel use and CO2 emissions spelling the end to un-cleanable furnace convection tubes.”