“One at a time”, but in the same region of build: The U-profile gutter has not to be welded, neigther has the loose inner condense mantel.
They can both be easily lifted out for cleaning.
Make the gutter as a “piston ring”. Make it 1" short of a complete circle. Make 5mm (3/16") thick stainless gables welded to the ends of the gutter.
Before welding them in place, bore and thread one of the gables for a 13mm (1/2") bolt. Screw the bolt 2" long all in (from outside the gutter).
Then put the gutter in place and unscrew the bolt, so it pushes hard against the other gable. This will enlarge the “piston ring” enough to keep it in place.
This makes it easy to vary the tilting angle for good flow.
Make the inner mantel accordingly “skew” in the bottom end, so it stands vertically in line with the silo.
Make a “hack” in the mantel, so it can “step” over the gable area.
Make a bent plate over the gables, from one gutter-end to the other one, to avoid dripping condense between the gables.
The gutter draining point (lowest point) opposite the gables of the “piston ring”.