Because the plates are running vertically it will cause liquid to pool, this obstructs the path for vapor and causes the vapor to literally bubble through the condensing liquid that is trapped in the heat exchanger.
Imagine running this graham condenser on its side vs vertical, what are the major differences?
What is this not suitable for horizontal distillation? Why is it more suited to vertical distillation?
this is a helpful read:
If the plate style was designed with different geometry it could be a contender.
one other thing about your drawing, the condenser on a rotovap has the connection to the vac at the top of the condenser. This allows the condenser to reject alot of solvent that would otherwise end up un your vacuum pump/ cold trap. Otherwise you might be evaporating in the receiving flask too.
I agree that most plate HEX’s certainly are sub optimal for condensing vapor under vac. Sondex and alfalaval (and some chinese mfg’s designs) have plate/frames designed for condensing vapor under vac. I use them on my FFEs, and subcool with a coil’ed type HEX. There probably is an inevitable amount of liquid hold up in these designs, but it is minimized compared to a traditional Liquid to liquid plate/frame HEX . (havent had to open mine up yet for servicing).
I’m not sure if any mfg makes one of these in a size that wouldnt be larger than the rotovap itself. I guess you could pipe vapor ducts from an array of multiple rotovaps to a centralized plate/frame HEX and reap the benefits of the space savings.
We are replacing the glass condenser on our rotovap with those four 6x48 shotgun condensers
Edit: @FicklePickle I realized I totally didn’t answer your question. Mr. @TheFire210 turned his reactor into a rather effective rotovap: shotgun condenser instead of glass, bellows where the bump trap would be, and a keg for a collection vessel. A T-port ball valve would allow vacuum to be broken and the keg to be drained while distillation continues (the condensate would collect in the bottom of the condenser but that would be okay as long as you dump the solvent quick enough)
We are actually shooting for 65 lph although the solvent isn’t ethanol. I’m concerned about the liquid holdup on the piping on the bottom of the columns (it’s upside down in the picture). Now that we welded it up I wish we’d run 3 inch or so
