The old onion stills used a tapered vapour path because they were so big that they lost a significant amount of heat. The reduction in size was to compensate to maintain a constant vapour speed.
Now our small stills don't have this issue, so you can keep the vapour path as big as you like - it is more about cosmetic appeal and cost than anything else.
There is some evidence that gradual tapers are better than sudden changes but both work to some degree. I would say to look at the total cross sectional area of the vapour path inside the condenser (if using a multi tube condenser) and use that as the smallest diameter in the vapour path. Then just work backwards to gradually increase to the diameter of the boiler output.Statistics: Posted by Myles — Mon Oct 14, 2013 4:21 am
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