New concentric-coolant direction ???

[Gatsby]

After much reading here, I'm reconfiguring my still.
7.75 Gal keg
Changing to electric 4500 watt heating, (Tri-clamped)
Control and measuring power from Chinese components
36" X 2" copper column
Alternating copper mesh and SS scrubbies
Sight tube, silicone seals wrapped with teflon tape
2 x 1-1/2 x 1 Concentric LM head all copper
I'm a bit more than halfway there. Tri-clamps throughout.
I also have the major pieces for a potstill head, as well as a VM head.

Last night I got to thinking about the Concentric LM
The 2" is just over 12" long. I spiral wrapped the 1-1/2 with a solid copper wire that is about 75% the size of the space between the tubes, and spot soldered it every 180 degrees. I figure it will help keep some of the coolant water from taking a shortcut from inlet to outlet, and increase the surface area of the inner tube a little.
So now my question:
From all I've read the cooling water should flow counter to the vapor, which would be from top to bottom. But it seams to me that this would create a pocket of air in the coolant chamber.
Am I correct? How do others do it? Comments!
Gatsby