On 29 Aug 2010 at 15:57, andrew heggie wrote: > When playing with smaller stoves (without the benefit of flue gas > analyser) I formed the opinion that the heat exchange to a Kelly kettle > must be inhibited by this effect. I experimented by putting some "fins" in > the central tube to disrupt the vortex but never came to any conclusion.
The vortex or swirl effect is usually very mild in a Kelly Kettle and the thing about it I noted was the way in which the flames seemed to stick to the tapered wall, whereas putting it on a TLUD created a centred flame (no vortex). I still haven't conducted Crispin's chimney baffle experiment to see if that centering can be overcome. Angle of air hole into wind also affects the swirl with the Kelly as might be imagined. It is not invariably a noticeable feature. What I did notice in the youtube video of the BioLite campstove was its apparent employment of a strong vortex compared with Tom's stoves for eg.: http://www.youtube.com/watch?v=JmHCIBvI6vE Also, does anyone remember at least a couple of decades ago, an Israeli invention IIRC which was featured on UK TV programme 'Tomorrow's World', except tomorrow never did come for it. It was an aftermarket cap to place over a conventional gas hob burner which brought the flame out on top of the burner and swirled it into a vortex. They claimed something like 30% fuel saving over the conventional burner which has no centred flame. And that was the first and last I heard of it! Neil Taylor _______________________________________________ Stoves mailing list [email protected] http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org http://stoves.bioenergylists.org http://info.bioenergylists.org
