hello kevin, here some copies from the swiss gengas book from tilman (search under Til )…
slag build up in charcoal gasifiers, different constructions
and crossdraft, where the problem comes up that the slags leads the heat too much to the shell of the gasifier , and so the protecting effect from coal around the hot area exists not more…and further creates disturbs with gas-flow…
therefore i like the design of eddy ramos (ramosedmundo) with his nozzle that enters from the bottom, so less possible heat stress for the nozzle i would say…
easy water drip installation, the water cannot flow the gasifier when forgotten to close the valve…
the slag build up makes the form of a crater and from my modest insight this protects the nozzle , further one can make some heat resistant stones around the nozzle for prevent nozzle contact with the really hot area..
what i would modyfie at this design: i would not make the gas outlet on the top of the gasifier, but in about maybee 30 cm over the nozzle to avoid too much coal dry out…but of course than is needed a additional cooler..
.in the swiss book is also claimed that high speed air flow must not be connected with cross-draft design…
English-Manual-V3-PDF.pdf (2.1 MB)