[Gasification] water gas and IC Engine exhaust gas tempretures

[Ken Boak]

Dan, Jeff, Jonathan and List,

Extracting heat from the coolant circuit using a water to air radiator will
only result in air temperatures somewhat below 100 C  (212 F).

Greater temperatures could be achieved using an air preheater that surrounds
the exhaust manifold.   Temperatures of 300 C are available there - but gas
to gas heat exchangers tend to be bulky and not easy to construct.

Why not take a tip from Reverend Robert Stirling's notebook, and build an
economiser, or regenerator?  The device was used for pre-heating the air for
blast furnaces, and run in a batch mode.

In one embodiment it would be a stack of high density magnetite bricks - the
kind that are used in electric "night" storage heaters.

A  7.5 kg brick can typically store  0.75kWh of heat energy, easily at
temperatures up to 600 C.

The hot engine exhaust is passed through a stack of bricks contained in an
insulated box, for several hours, to heat them up. The exhaust is then
diverted to a second box, and the process continues.  Air for the gasifier
is then drawn through the first box, giving it considerable preheat.  Any
soot in the exhaust that remains in the box, will eventually find its way
into the gasifier and be consumed.

The same approach could be used to make use of the heat contained in the hot
raw gas from the gasifier.  Does anyone have a typical temperature  range of
the gas drawn out of the grate?

Ken