The economiser operates by allowing gas to flow on both sides, thereby exchanging heat.
In this case, it is designed as a fixed tubesheet heat exchanger with pure countercurrent flow, where 2 shells are stacked in series. This approach handles the temperature overlap as efficiently as possible within a compact design.
Duplex was selected for the wet gas on the tube side.
This is a Shell & Tube heat exchanger. A one-pass shell with fixed tubesheets and removable bonnet headers. 2 shells stacked in series. TEMA type 2 x BEM 273/7000 constructed in carbon steel with Duplex tubes and tubesheets. Designed and built according to PED cat. IV/Mod G + ASME VIII div. 1, TEMA R, and API 660.