On Jul 24, 2010, at 10:33 PM, Greg Manning wrote: > > Greetings Brian, and List. > > > Brian, a blue flare only happens during cold air AND/OR rotting wood, both > contribute to a higher methane (CH4) component in the gas.
Okay, interesting. I'm wondering if air mixing at the flare could also be a factor. If I "flick my bic", light up a butane lighter, the flame is yellow with a bit of blue at the very base, very much like our flare. But if I light up a propane torch with a point burner, with air inlet holes prior to the flame outlet, that makes a blue flame. I think I'm going to "ignore my mom" and go play with some fire.... take a propane torch and cover up the air inlets and see if I get a yellow flame. If I do, then maybe my gasifier flare design needs some work. Wouldn't be very hard to put some air inlet holes in that pipe before the final outlet... > > Violet with light yellow wisps in the tips is considered a high H2 > (Hydrogen) component. > > Red is tar, plain and simple. That is helpful. Has anyone tried to mask out different colors with filters? For example, if I I view the flare through a yellow piece of plastic to mask out the yellow, would red or blue then be more evident? > > You might have violet, BUT it's being masked by the red, only way to find > out is if you can measure the core temp, near the hearth (just above it) > 800c (1470f) is considered Ideal, higher up, in the core, 1100c (2000f)is > common, if your temperatures are lower than that, that would explain the > tar-red. Okay, you lost me there. Where are you talking about? We do have five thermocouples (TCs) in our firetube and another in our air input manifold. The values displayed in the video clip are from the TC immediately below the air input manifold which I'm calling the hearth/combustion zone. Then we have another TC a few inches below that at the bottom of the firetube, an inch or so above the floor of the grate; I'm calling that the reduction/char zone. Do you really mean physically ABOVE the air input manifold? We do have three TCs above the manifold up the fuel stack but we consider those to be "safety indicators". If our fire starts to climb the fuel stack, we want to know that ASAP! At any rate, the TC that is immediately above the air input manifold indicates that the temperature there is actually pretty variable. In the video I linked in my original post, during the afternoon tests the temperature immediately above the air input manifold generally ranged between 370 - 650C (700 - 1200F) and during the night test it generally ranged between 815 - 925C (1500 - 1700F). But again, we're running downdraft and those are the temps from ABOVE the air input. To reiterate from the video, what we observed during the specific times of those afternoon and night-time clips were: Afternoon clip: Hearth/combustion zone: ~815C, 1500F Reduction/char zone: ~1040C, 1900F Night clip: Hearth/combustion zone: ~650C, 925F Reduction/char zone: ~925C, 1700F -brian > > Greg Manning, > Canadian Gasifier Ltd. > Building Hi-Performance Gasifiers, Since 2001 > > Brandon, Manitoba, Canada > 1 (204) 726-1851 > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]]on Behalf Of Brian and > Cara Paasch > Sent: Saturday, July 24, 2010 9:08 PM > To: Discussion of biomass pyrolysis and gasification > Subject: [Gasification] Can't get to blue flare > > > Hi all, > > We recently started testing our downdraft gasifier. So far we haven't been > able to move from a yellow/red flare to a blue flare. I've searched the > gasification archives and as best I understand, we need more air running > through our system. Is that correct? We've increased the air over previous > test runs but our flare is showing no sign of going from yellow to blue. > > As shown in this video: > > http://www.youtube.com/watch?v=9X6WPlhyOWc&feature=channel > > we have a pretty clean flare, no obvious smoke, but day or night, our flare > is most certainly NOT blue. > > Anything else we should be considering? > > Thanks! > > -brian > > PS Our wood moisture content is less than 15%. > _______________________________________________ Gasification mailing list [email protected] http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org http://gasifiers.bioenergylists.org http://info.bioenergylists.org
