Gidday to everyone at Drive On Wood.
I am an Australian and just about to start building a gasifier based on the GEK designs with a TOTTI. It will used to run a 5KW Quicksilver(Generac) generator set. This generator was made as a marine generator, the engine is a Nissan 1.235 Litre single overhead cam running at 1500 RPM. I believe the same engine was used on 7.5 and 10 KW versions of the generator. So I have plenty of power up my sleeve to allow for for wood gas and still get 5KW from the generator. The mechanical governor on the engine is setup to only open the carburetor about 1/3 of it's full potential.
As I will never be using more than around 10HP to get to the maximum output of 5KW. Mostly it will be running at around 1.5 to 2.5 KW I am planning to reduce the hearth down to around 50mm (2") as the 75mm GEK is designed for up to 10KW. From my research I believe the larger size will be asking for problems. Fuel will be wood chips and I am planning to put a 2 RPM spiral agitator from the top right down through the all the zones to the grate. Similar to the GEK TOTTI I am also planing to run the engine exhaust into the pyrolysis zone through a chamber made of 2 tubes around 150mm and 200mm diameter. This is to recover the waste heat to help increase the heat in the gasifier to keep temperatures up due to the low power output required.
Has anybody got any thoughts on my ideas(hopefully I won't get shot down in flames :)), this is my first attempt at woodgas, but I have been researching this and thinking about it for about a year now.
Thanks in advance