I am sure we all have an interest in simple gasification, but the rules of gasification are the same today as they were in WW11. It is true that the gasifiers used in Australia and New Zealand were simple compared to those used in Europe, but then ours were more likely to be home made, but they were built to a fairly common design. I should mention that Australia had a lot of very old ringbarked dead wood and this was often used instead of the charcoal, so you find some confusion in how people thought their gasifiers worked!
Most cars had charcoal or precarbonised coal/coke, so condensate and tar as experienced with wood gasifiers was less of a problem to the engines. Most simple to build were cross draught with one rather large air nozzle that had a water jacket round it to generate steam. This was introduced into the nozzle where it reacted with the incandescent char to produce the hydrogen. Some had a small control valve that dripped the water directly into the hot nozzle, while others had circulating water through the nozzle jacket to prevent it from melting. The nozzle could be moved in or out through a sleeve in the side wall to obtain the correct distance from the grate on the opposite wall.
Cooling and cleaning usually relied on long connecting pipes with a sawdust or cloth filter with many variations introduced by individual circumstances and availability of materials.
Manufactured gas/air mixers became quite elaborate and were cast in brass (I have one) but these were for only one model of car I believe, here in New Zealand.
While travelling in Queensland I actually found a charcoal gasifier at a kiosk park in the Bunya mountains west of Kingaroy. It still had charcoal in the bottom, but was complete in every way although a bit battered.
Front of gasifier. Eliptical shaped case showing:
* Clean out port in front bottom
*Single air nozzle bottom left with water tube connection on top and bottom of nozzle
* Gas outlet pipe rising from bottom right entering cyclone with bottom cone rusted away. Gas leaves cyclone out of top then crosses over to second cyclone on rear left
Rear of gasifier showing
* Cyclone cross over gas pipe and gas outlet pipe (battered) exiting top of right hand cyclone
* Rectangular water tank for nozzle cooling and steam generation with side pipe being possibly hot water return connection
* Mounting brackets possibly for tractor or bumper bar mounting of car/truck
|Eliptical case has internal wall opposite air nozzle with vertical barred grate fitted into a simple slide so that it can be removed to clean out char between grate and gas outlet. Lid is just clamped down with central thrust, but with no pressure releasing safety valve function|
New Zealand made cast brass gas/air mixer.
|Gas enters through left hand end, air enters top left controlled by a butterfly valve. Throttle butterfly with connection lever is for gas/air mix speed control. Flange on top right mounts directly onto the engine manifold. Bottom flange right connects to gasoline carburetor|
|Shaft passing lengthways through main body is sliding changeover valve that shuts off carburetor or gas/air mix.|