The difference is when you use four 2" columns, each 2" column will be running at 1/4 the power of a 4" column so to speak and requires smaller structured packing. 2" columns would have approx 1/4th the amount of falling reflux as well as 1/4" the amount of rising vapor. 4" columns run at 4 times the power and needs larger structured packing otherwise it floods. Think about the amount of vapor rising through a FINE structured packing meeting all that reflux trying to make its way down. This is the same principal that causes relatively fine screens flood columns.Yummyrum wrote: ↑Thu Sep 08, 2022 1:30 am What always gets me is that 4"is 4x the area as 2" .
So is it not the equivalent of 4 x 2" columns in parallel or side by side ?
If a 2" column can run with 2kw , then 4 of these would use a total of 8kw .
If each column can produce say 95% without flooding @ say 1l/hr then surely four in parallel would be producing a combined output of 4l/hr @ 95% .
So why is it when we take away the pipes and combine 4 x 2" columns into one 4" column , that it all turns to shit and floods and makes low abv and needs to be taller and need different size packing ?????
Otis appears to be using some of the small bits that are sized for a 2" column inside of his 4" column. That size flooded my 3" column so I would expect it to flood in a 4" column. I believe the perforated plate and the fine rock is the main problem. If he replaces that with a wide open support, ditches the tiny rock THEN tests the larger rock all on its own ... if it still floods then he needs larger Lava Rock. He's using the same size I use in my 3" which works flawlessly. His column has twice the cross-sectional area than mine though.