Globular funnels are somewhat less convenient to use in extraction, as they don't center as easily, and the interphase goes a little faster when draining it. They are ideal for conversion into a Perkin triangle as shown in
Post 288323 (missing)
(lugh: "Perkin triangle", Newbee Forum) in the illustration, or any other use where one wished to have a round bottomed flask with a valve at the bottom
As far as extraction, SWIL has a few, but none larger than 2 L
instead of using the larger ones, SWIL uses a glass jug or carboy or a PE drum, using stirring for agitation, and a siphon to separate the layers
The interphase layer is put into a smaller container to separate it, eventually it fits within a 2 L funnel
SWIL says shaking a 6 or 12 L funnel is a lot of unecessary work