the moog
All the information you should need here.
Re- raschig rings, I believe stainless stil pan scrubbers are more
efficient. They work well for me anyway.
Diameter and height of the tube depends on the energy input into liquor to
be distilled and cooling in the still head.
Too much energy and the column will flood, column too wide same problem.
column to narrow water vapour will pass to condenser.
Read from homedistillers and all will be revealed. hope this helps.