ValterBorges wrote:You think burning nut would be better more air?
or buckwheat less air?
or no effect?
where would you put the pipe?
I think burning buckwheat would cause more puff backs. Looking at the A-A Bureau of Mines report it says the following:
"The equipment was tested under regular house-service operating conditions. To use Buckwheat in the Anthratube it was found necessary, owing to its more compact fuel bed, to drill a 7/l6-inch-diameter hole in balance plate W (fig. 4), so that more air could be provided over the fire. Without this air, the CO in the products of combustion would frequently, during start-up periods, build up to some 13 percent or enough to create an explosive mixture. The mixture would ignite and cause a “bump” or small explosion."
To me this says the denser coal packing with buckwheat raised the production of CO. Apparently the critical percentage is around 13%. Other data in the report shows percentages around 12.5%. With this lower number there is no mention of puff backs. Interestingly it says during "start-up periods", not the end of ashing.
The CO measurements were made at the boiler breach. I've got an Orsat and can make these measurements. I'll have to dust it off and collect some data. If the difference between 12.5% (no problem) and 13.5% (problem) is all the margin there is, almost anything that would increase the air flow would likely help.