These units are flanged directly on a column and a close temperature approach is a very important design factor.
In this case, a 4°C temperature approach was required by the client and due to the high proportion of chlorides in the water, the material of construction selected was AISI 904 for the plate pack and all water wetted parts.
As you can see from the 3D view (above), the plate pack is located inside an outer shell (made of carbon steel) and the condensates are returned to the last tray of the column.
Due to the possible presence of fines in the process gas, it is mandatory to use a free flow channel so that these fines can pass through the elements without blocking these channels.