Keeping it simple

I was reading all the posts and ideas about the hearth construction.  I want to make sure I understand well why it is constructed the way it is.  The inverted "V" style is to get the reduction, but also to allow the void formed to just fill up with ash, thus making its own "hour glass" shape based on the angle of repose of the ash.  The main purpose for this being to form a hearth out of ash that acts as cast/insulation?  So why cast one out of ceramic, or a refractory material, and why make in an inverted "V" at all, why not just use a flat plate with the right size hole in for reduction.  It would form some what the same angle of repose cone out of ash, not as massive/deep, but still there none the less, and no making cones.  The other thing I see people doing is actually making an hour glass shape out of all steel (stainless or carbon steel).  It seems that the idea hear is to make smooth surfaces for the char bed to flow on thus thinking this will reduce bridging, make for smooth flow of fuel through the unit, etc.  Is this really going to be effective, and now you have no insulative value, just thermal energy being stored in the steel.  I have my own millwrite buis. and work with hoppers, storage bins, cyclones, conveyors, augers, pelleting equipment, etc.  I know how different materials flow into, and out of cone shaped hoppers.  In all of the ways I have seen guys making the hearth, none of them seems to make much sense TO ME.  All alot of work, using tools that most guys don't have.  And when and if we really need to rely on making a simple gasifier because the world goes to pot, how are we going to know what to do, and make one work if it not just the simplest of designs, that any "JOE BLOE" can make. 

Please note, I am not trying to ripp on anyone, or what they are building.  Just trying to understand and want to build the simplest, and most effective gasifier.  Techknowlegy is great, but what if we didn't have it, then what?

Keep up the good work all, and thanks for your patience with me.

David