Our hearth is a bit on the large side, about 250 mm. The raw material for that part was free, we like cheap and we love free.
Our final goal is not to run an ICE, but we do need clean gas for roughly the same reasons an ICE does. (Piston + cylinder + grit = bad.) Per my math, we simply are NOT going to be able to get up to optional air feed to make our beast happy. So instead of producing nice clean producer gas in the gasifier, I guess we're stuck on the post-gasifier gas clean-up track. Creative application of filters... Oh well. -brian On Aug 2, 2010, at 5:05 PM, Arnt Karlsen wrote: > On Mon, 2 Aug 2010 14:16:38 -0400, Brian wrote in message > <[email protected]>: > >> And it is generally accepted that the optimal air blast through the >> tuyeres is (roughly) between 25 - 35 m/s > > ..if your hearth diameter is in the 100 to 300mm range for > modern 4-strokes, yes, or in the 220 to 300mm for the old > big 2-strokes. ;o) > > ..to eat the entire range, you wanna be between 22m/s for > 70mm to 33m/s for 300mm, and 14.7m/s to 22.1m/s for the > big old 2-strokes at full load, according to Gengas. > The "lower" speeds for 2-strokes, are pulse averages, > smaller faster engines will have uniform suction thru > the gasifier. > >> (m3/m2-s) air, yes? >> >> (Based on air volume calculations at 0C.) > > ..nope, "full load" according to Gengas, means "0.9Nm^3/cm^2h > thru the hearth", or "2.5m/s", both if you do the math on the > messy "metric" units or re-check the Gengas math. ;o) > > ..keep in mind your tuyere air flow is only 60% of your gas > flow, you _produce_ the "other 40%" gas in the gasifier. ;o) > >> -brian >> >> >> On Aug 2, 2010, at 12:34 PM, Arnt Karlsen wrote: >> >>> On Sun, 1 Aug 2010 20:51:39 -0400, Brian wrote in message >>> <[email protected]>: >>> >>>> Hi all, >>>> >>>> When calculating gas flows through the input ports (tuyeres) and >>>> then across the cross section of the constriction/hearth, what is >>>> typical in the art of wood/biomass gasification? To do the gas >>>> volume calc's at ambient air temp? Hearth temp? European normal, >>>> 0C? US standard, 77F, 25C? Or something else? >>>> >>>> Thanks! >>> >>> ..the Gengas uses 0 degrees Celsius for its "Normalkubikmeter" >>> or "Nm3" standard in its gas reaction and gas flow calculations. > > -- > ..med vennlig hilsen = with Kind Regards from Arnt... ;o) > ...with a number of polar bear hunters in his ancestry... > Scenarios always come in sets of three: > best case, worst case, and just in case. > > _______________________________________________ Gasification mailing list [email protected] http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org http://gasifiers.bioenergylists.org http://info.bioenergylists.org
