(06-22-2017, 09:40 PM)Robert Adams Wrote: I toss sawdust and chips on the fire in the grill all the time. The fine dust will burn but its hard to get the mixture just right it usually just smothers the fire and makes nice smoke.
From what I have been led to believe during hours of fire safety classes is the triangle must have 1) Heat 2) fuel and 3) an oxidizing agent or as we commonly call it oxygen. Take any out of the triangle and fire stops. To get that mix in flying wood dust, the fuel, the heat source must be perfect, and having the fire just the correct temp matters here. But the deal breaker is the perfect storm of fuel, and oxygen in perfect amounts, with the fuel perfectly dispersed into the oxygen flow you might get a flash 1 out of 50 attempts.
In an uninsulated barn, heating with a 170,000 BTU salamander heater, going full blast I had been sawing almost non stop on the TS for several hours. The air was completely full of floating dust, and WHAM the entire place 32 x 48 barn, with 10' walls was just engulfed in a fireball, which was gone as quick as it came, because it burned up all of the dust, thus no more fuel. I probably should have needed clean underwear, but I didn't. I had somewhere around 17,000 bd/ft of wood in the barn at the time, but the airborne dust was all that went poof, thankfully. I did quit for the day, and when I got in the house noticed my face was all black, filled with ash, and It turned out my eyebrows didn't stay around.
That night at dinner I told LOML that I thought I needed to do something about heat in the barn. She just turned an eyebrow up and said, big heater not working out too well? CL sold quickly as it was almost brand new. After that experience I understood a lot more about the fire triangle than I had ever known from all of those classes
Luckyyyyyyy, yes I was.
I do not believe a handful of mixed dust and chips will ever get that correct mix, sure it will burn, but what it won't do is cause that explosive fireball. That truly is a perfect storm, and it would need to be dust, not chips.