[Stoves] the 150 gasifier in operation in Vietnam

Alex English english at kingston.net
Sun Mar 4 10:23:10 CST 2012


Hi Crispin and Paul,
Bluff bodies (BB) are refered to in fluid dynamics generally   for which 
combustion of gases is a subset. The definition of a BB
"a solid obstruction in a fluid stream, having a broad flattened front 
and providing a shelter for small scale turbulence and zones of low 
velocity; a stability assister."
(from the  North American Combustion Handbook (Vol 2))

So does a screen qualifies as a bluff body? It can be a flame holder as 
can a single wire in the path. We have  a screen burner on our  propane 
refrigerator but the flame is down sream of the screen. I don't think 
the screen glowed.

Paul's burner appears to have good flame holding at the holes in the 
burner head. He mentions  the screen protects these flames from the wind 
and that combustion is below the screen.  So in this case it is not 
clear that there is any combustion happening in or on the outer surface 
of the screen although it could be invisible to our eyes.  So you could 
say that there are two screens, the holes in the burner head being the 
first screen, the BB perhaps, and the second is simply a radiator/wind 
screen. The small pressure drop across the screen also helps distribute 
the flow evenly.

All in all,  great result= great design.

Alex



On 04/03/2012 8:26 AM, Crispin Pemberton-Pigott wrote:
> Paul, what you are describing are the effects of a 'bluff body'. It is why they are sometimes used above a flame.
> Crispin
>





More information about the Stoves mailing list