[Stoves] Stove comparison/ PM

[Alex English]

Crispin,

Glad to know there are still mysteries to be probed.


>
> Agreed. I am becoming more convinced that temperature has more to do with it
> than perfectly balanced air supply. I am seeing some unexpected things. One
> is a very low PM level from a TLUD stove with 0.5% excess air.

I assume this is with coal. Do you have this data logged to share?  Are 
you doing PM testing with wood fuel?
>

>
> Interesting, eh? Burn cleanly the volatiles then burn even more cleanly the
> carbon. Perfect for biomass stoves. To put a number on it, stoves with
> nearly no non-carbon in the fuel pile are consistently produces only a few
> microgrammes of PM over a period of several hours. It is in the non-carbon
> gasification phase that the PM is produced (potentially). As you know, the
> essence of the biomass gasifier stove claim is that it is the gasification
> process that creates a clean burning gas, by leaving the PM producing carbon
> behind. It is not supported by observations that include real-time
> monitoring of the PM (i.e. watching when it is produced and when not).

Snuff a biomass fueled TLUD and its a PM cloud. So its the burner that 
matters. If PM shows up above the flame then it is likely sneekage due 
to insufficient mixing and/or too large a space for the flame PM laden 
gasses slipping by in the outside lane.

Good wood pellet stoves have low PM without being gasifiers. Low 
moisture helps. What role does the flue particle size and distribution 
and depth on the grate play? Your coal is pea sized, I think? Have you 
found any  differences with large sized fuel?

Alex