Hi, Tom!
The surrounding outlet starts with a conical bell on the char (locally), instead of a “scraping” mesh (grating) between the two tubes in the char!
I take it, that you mean Torsten Källe’s charcoal generator from 1942.
In both cases the silo char mass will cover the outlets.
In this case, a real air blasting from under the bell cavity, deep into the char without the nozzle toutching the char.
Max