Revamping to convert a hot wall converter to a cold wall one.
Improvement in terms of life, reliability and safety.
The experience shows that the use of hot wall pressure vessels for ammonia converters is risky, as after some years of operation the vessels may show extensive damages due to the combined effect of hydrogen attack and nitriding. Casale has developed and applied a design to revamp hot walled ammonia converter to cold wall design preserving the existing pressure vessel.
This is achieved by installing inside the vessel a new cartridge, which houses the catalyst baskets.
- The cartridge allows flushing the vessel with a stream of cold gas, which, after passing through the annuls between the cartridge and the vessel, is mixed with the main gas and then enter the catalyst basket.
- The new nozzle required for the cold gas is located on the HP top cover.
- The loop performances are unaffected by the new design, keeping the same production and conversion efficiency.
The new design is such that it can be implemented within a normal turnaround. It has already been successfully applied and it is in operation since 2011.