We have Power Recovery turbine (PRT) to recover the power from Flue gas coming from regenerator. Because of seal gas failure Flue gas about 600°C coming outside from PRT. We don't have any back-up seal gas on site. How can we tackle the leakaged flue gas from PRT?
Alan Goelzer, Jacobs Consultancy, email@example.com
In best practice designs of FCC/RFCC units, the PRT should have robust inlet / outlet butterfly valves and full bypass with controllable / robust butterfly valve and the PRT should have been driving a generator with FCC main air blower driven by its own induction electric motor and helper steam turbine or full megawatt condensing steam turbine. Then the PRT can be placed on standby and allowed to cool down. Any residual leakages from seals can be managed using steam sweep purges until a shutdown window emerges.
Presumably if the FCC/RFCC embodiment is set up so the PRT must be in service, then external steam sweep purges are being applied to the leakage and plans are being sorted out to take a short unscheduled forced outage to repair the seals.