New Industrial Burner

Key challenges

The main challenge for RJM at this refinery in Ireland, was to remove flame impingement on the furnace tubes, as this was limiting boiler steam flow and flexibility. In fact, ever since commissioning, output on the unit was having to be restricted to 10t/h of steam, representing just 50% of the boiler’s rated output. In 2012, the burner OEM made an attempt to resolve this by introducing burner modifications, but these proved to be unsuccessful. In addition, RJM’s modifications had to be achieved in a way that ensured NOx emissions remained below the 200mg/Nm³ threshold. The root cause was that the SG6 boiler has a narrow furnace, resulting in wall flame impingement with ‘off the shelf’ industrial burners.

However, RJM was able to tailor its industrial burner design to ensure the flame shape did not impinge on the boiler tubes at over double the previous heat input, whilst comfortably achieving the emissions requirements.

RJM Solution

By means of an innovative combustion model, combined with a detailed kinetic mechanism, RJM was able to CFD model the existing boiler, matching the flame boundaries and the emissions levels recorded on site. Once the baseline conditions had been established in the model, RJM was then able to design the appropriate modifications needed to upgrade the unit.

New RJM ultra-low NOx CleanAir Burner firing a mix of natural gas and off-gases at the refinery

Results

The solution provided to the customer resulted in a phenomenal performance improvement in terms of flame shape and allowed the boiler to generate up to 18.2 MW whereas previously, the unit was restricted to just 8 MW. Obtaining the higher output from this boiler enabled the refinery to shut down a less efficient boiler, so that it is now able to meet total steam demand with two boilers in operation, instead of three. NOx emissions were also successfully reduced well below the guarantee level, with no registered CO at the boiler outlet, indicating efficient and stable combustion.

Irving Oil was delighted with the solution provided by RJM which allowed it to meet its emissions and load requirements. Irving Oil also recognised RJM for the depth and quality of its work and its professional commitment to discuss how possible improvements to the SG4 boiler could be achieved.

“SG6 has been running all week at 12-13MW with no issues and I just wanted to say thanks so much for the work on this – it’s a phenomenal improvement.”
John Lynch, Energy and Oil Movements Processing Manager, Irving Oil, Whitegate Refinery