kiln idea. opinions?

[woodpeckerlips]

I'm thinking of making a kiln. Refer trailer or conex box.  I like the refer because its insulated.  Take a 24" pipe and put a 20" pipe inside it. Make the inside pipe a wood stove and the outer 24 a water jacket.  Recirculate pump with a loop that goes to a heat exchanger in the kiln. Fan behind the heat exchanger.  Both pump and fan to come on by thermostat. Vent at opposite end. Make shift boiler on the outside. Open to atmosphere boiler. Not pressurized!
   Without a meter to determine.  How long does someone think it would take to dry 1x materials if the contraption was half full? 
Would I have to feed wood every 8 hrs or so for 3 to 5       days or for a month?