Need a help on eliminating 'wall between meshes
 

Hi, I've been working on the sturctured hexa mesh of stators part.

Firstly, I constructed grid(Premesh)
for one passage of the stator region with good quality,
then using 'Blocking-Transform Block-Copy periodic Blocking'
to copy the geometry and block for the whole passage.

Then, I transformed the premesh into unstructured,
checked the mesh, carried out 'merge vertex with tolerance'.

then here's my questions.

Firstly, I can't seem to eliminate 'Shells' from parts for Boundary condtion.
I'm using in-house code that only offers B.C. as WALL/OUTLET/SLIP condtions and this solver takes 'Shell' or interface mesh shown in the picture as the wall, and I can see 'Shells'(I separated this shell from other mesh) in 'Surface-one sided' section in 'Family Boundary condtion' shown in the right below corner of the picture.
This code basically uses the msh file from GAMBIT and Fluent v6 solver setup.
For these reasons, interior or interface option doesn't work.

In other words, is there any way I can merge 'shell' into other mesh so that I don't have to select B.C. for shell?

I tried to build mesh without surfaces on both sides but mesh construction didn't work well..


I will really appreciate your help..