No more failures in ammonia plants with vertical PGCs with ARVOS I SCHMIDTSCHE SCHACK’s innovative solution

No more failures in ammonia plants with vertical PGCs with ARVOS I SCHMIDTSCHE SCHACK’s innovative solution

For increased production capacity of ammonia plants at reasonable investment cost, plant revamps and debottlenecking are attractive options. This in particular is the case when considering the waste heat system downstream the secondary reformer and here especially the process gas cooler (PGC).

Of the about 400 ammonia plants in operation, mainly the older ones have vertical PGCs installed. Being built in the water tube design they lack reliability caused mainly by two reasons:

  1. Sludge deposition at the water side in the tubes at locations with high heat flux lead to local overheating, so called “hot spots”.
  2. Tube vibration induced by process gas flow around the tubes leads to tube damages.

Asked to find a solution for these problems we developed a new vertical PGC design based on its unique Schmidt´sche® double tube design. This design proved its reliability and durability in more than 7000 units in operation in the ethylene and gasification industry. It combines the advantages of the fire and water tube designs and is easily maintainable.

Units of this design have been in continuous operation for over 30 years.

The new vertical PGCs with higher capacity have to fit into the old units` footprints – and they do. This has the advantage that the existing foundations inside the plant steel structure can be used. In addition, no new plot space for the new PGC is required, which would reduce the available space for maintenance activities. The existing gas transfer lines as well as the existing water/steam piping can be used with minimal adjustments. This vertical PGC replacement concept has highest customer benefit, as it saves cost considerably while the exchange of PGCs can be performed in the shortest time.

SCHMIDTSCHE SCHACK | ARVOS GmbH´s double tube design process gas cooler for ammonia plants

The replacement of the vertical PGC should also involve considerations of the interaction with the water/steam side, i.e. steam drum and interconnecting pipes. This can only be sufficiently accomplished by a solution provider like SCHMIDTSCHE SCHACK | ARVOS GmbH. In cooperation with CASALE we are able to deliver the maximum customer benefit.

CASALE AS is the ammonia process and overall plant expert whereas SCHMIDTSCHE SCHACK | ARVOS GmbH stands for excellent heat transfer technology, in this case: vertical Process Gas Coolers for ammonia Plants.

Detailed insight to the SCHMIDTSCHE SCHACK | ARVOS GmbH replacement boiler concept will be given by Dr Joerg Weidenfeller at the AIChE Annual Safety in Ammonia Plants and Related Facilities Symposium in Toronto September 16th to 20th, 2018.

If you’re not going to attend the conference, please don’t hesitate to contact us directly for further information.