hehe.. the mythical turbo'd hookah. i've often imagined this, but the engineering would be a huge feat. here's what i'm thinking...
2 hose hookah
the world's tiniest, low inertia turbo
plenty of tubing-- both metal and pcv
a restrictive air filter
a bowl with an air tight clamp on lid
home-made water to smoke intercooler
some fittings and whatnot
i think that's about it. here's the basic walkthrough...hopefully the m$paint illustration helps.
OK: your hookah is set up as normal, but using an airtight clamp on lid for the bowl and no regular hoses.
hose 1 connects from the bung on the hookah to the input of the "exhaust" side of the turbo.
your regular smoking hose connects from the output of the "exhaust" side of the turbo impeller. when you smoke, smoke is pulled through the impeller side, turning the compressor side. this sucks smoke from the vase through hose 2.
hose 2 connects from the second bung to the input of the compressor side of the turbo. this will make the hookah pull from both hoses simultaneously. smoke from hose 1 goes directly to the smoker while smoke from hose 2 enters the intercooler.
smoke drawn from hose 2 passes through the intercooler (so as not to return more heat with the recycled smoke) into the mixing chamber.
in the mixing chamber, cooled smoke and fresh air are drawn in and mixed to be pulled across the coals and back into the hookah. the restrictive air filter is necessary to create equivalent pressures at the chamber inputs. otherwise you would just end up pulling in fresh air and negating the entire purpose. mixing fresh air in is necessary to prevent build up of CO2 from extinguishing the coals or choking you.
heat resistant tubing connects from the outlet of the mixing chamber to the inlet of the airtight bowl lid. this returns cooled smoke to the hookah inlet while still providing oxygen for the coals. the tubing must be heat resistant because the air-tight bowl lid will get hot and would melt pvc tubing.
i think that's about the full description. don't know if it'll make sense to anyone else.
inherent problems with this setup:
no potential for purging... if you blow back into the smoking hose, it would spin the turbo backwards and i'm not entirely sure what the outcome would be, but without a blow off valve somewhere, it wouldn't be good... i think it might actually recycle air/smoke backwards through the hookah
the mixing chamber maybe should be before the turbo compressor... i'm really not sure at this point, but i'm not going back to fix the diagram.
once you have your miles of tubing and accessories set up,it might be too hard to pull the hookah. way too many variables to even speculate.
ROFL, this got way over complicated and now my girlfriend is laughing at me for putting way too much effort into an imaginary (probably purposeless) device. way to put my engineering degree to good use...