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wood stove and spins faster as the stove --Apple-Mail=_E42A442D-5852-492A-8B61-3334541AE499 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 I couldn=E2=80=99t stay behind so dug into the Christmas box and found = the angels in original box! Besides the headings that you quoted it also states: Manufactured by = Automatindustrier AB Gefle- Sweden. Henk > On May 27, 2020, at 10:23 AM, David Webster <dwebster@glinx.com> = wrote: >=20 > Hi again Henk & All, >=20 > Original box found; says "Swedish Angel Chimes" on main panel: = "Angel Chimes A Product of Swedish Handicraft" on end tab.=20 > YT, DW, Kentville >=20 > -------- Forwarded Message -------- > Subject: Re: [NatureNS] Stove Blacking and heat transmission > Date: Wed, 27 May 2020 08:44:56 -0300 > From: David Webster <dwebster@glinx.com> <mailto:dwebster@glinx.com> > To: naturens@chebucto.ns.ca <mailto:naturens@chebucto.ns.ca> >=20 > Hi Henk & All, It is one of these effects which must be seen to be = believed; the difference between 'black and white' (via dull grey). That = Swedish connection may be in error. Will be on the lookout for the = original package likely about 50 years old. >=20 > Dave W. >=20 > On 5/26/2020 9:13 PM, Henk Kwindt wrote: >> Hi Dave and All, >>=20 >> I don=E2=80=99t really have anything to add to your explanation but I = thought it interesting that you have one of those =E2=80=9Cangel = carousels=E2=80=9D! >> We have had ours for at least 40+ years, they were quite popular in = The Netherlands in the 60s, didn=E2=80=99t know they came from Sweden. >> Ours is packed with other Christmas decorations so it is being placed = on the stove every year in Dec. >> We have not used the candles to =E2=80=9Cpower=E2=80=9D it for a long = time. >> Since we have a more modern high efficiency stove the black top is = not directly accessible so I won=E2=80=99t be able to repeat your = experiment. >> Henk Kwindt, Cow Bay, NS. >>=20 >>=20 >>=20 >>> On May 26, 2020, at 7:47 PM, David Webster <dwebster@glinx.com> = <mailto:dwebster@glinx.com> wrote: >>>=20 >>> Hi Steve & All, >>>=20 >>> No my mill is powered entirely by upward flow of warm air; a thin = circular sheet of brass clipped to form eight vanes which slope downward = to the left. This fan consequently turns near side to the left. = (Clockwise viewed from above). >>>=20 >>> The original unit, made in Sweden, was powered by candles and = intended as a Christmas table decoration. >>>=20 >>> The fan is supported by a brass plate with three arms on each of = which an angel hangs and a brass rod hanging from each angel rings a = chime as it turns. >>>=20 >>> I just stuck the working parts in a support made from a length of = burned out oven element, bent to be stable with the filling removed from = the vertical end by tapping. >>>=20 >>> Just to confuse matters; note that what we call clockwise (down on = the right side) is counterclockwise from the clock's viewpoint. >>>=20 >>> YT, Dave W. >>>=20 >>>=20 >>> On 5/26/2020 5:53 PM, Stephen Shaw wrote: >>>> Hi Dave, >>>> I=E2=80=99m not familiar with your named device or its principle of = operation, but we too have a small windmill that simply rests on top of = our (also black) wood stove and spins faster as the stove heats up. It = works as a Peltier device, with parallel hot and cold junctions built = into a short aluminium tower, the top of which is an air-cooled heat = sink. I think it cost ~$130 some years ago. The =E2=80=98hot' side of = the Peltier junction faces down to the hot stove top upon which the = frame rests, while the =E2=80=98cold' side is uppermost, and its heat = sink is cooled partly by the little rotating fan and partly by = radiation. With enough heating differential, the Peltier effect = generates a small current which is enough to turn a small DC motor that = carries the fan. >>>> Is this like your device? If so, you may have simply have cleaned = and in effect flattened the stove top a bit so the base of the device = makes better thermal contact with the Al base of the windmill, though = the black-body improvement should help a bit. A better solution in my = case and maybe yours would be to apply a thin layer of heat-sink = compound to the base of the tower. This is a messy paste based on zinc = oxide, used standard in electronics to attach a power transistor to an = aluminium or copper heat sink, while at the same time providing = electrical insulation. It would certainly enhance heat conduction to our = windmill, but the compound is white, sticky and difficult to remove once = applied: I would become locally unpopular if I so disfigured our black = stove top, so I haven=E2=80=99t yet risked the experiment. >>>> Steve >>>>=20 >>>> On May 25, 2020, at 7:55 PM, David Webster <dwebster@glinx.com> = <mailto:dwebster@glinx.com> wrote: >>>>> Dear All, >>>>>=20 >>>>> I heat the house mostly with wood burned in a fireplace insert = and, >>>>> apart from some air circulation in under the fire box, up behind = it and >>>>> out over the top, most heating is radiant off of the top. >>>>>=20 >>>>> For decades I have used a Swedish Christmas heat mill, sold for >>>>> candles, which I adapted for stove top use, as a measure of heat = release >>>>> rate. In recent decades it turned less frequently and for several = years >>>>> not turned at all even with a brisk fire so I suspected wear and >>>>> increased friction at pivot points. >>>>>=20 >>>>> The stove top had become dull grey in color so to improve >>>>> appearance I located a source of blacking last fall but it could = be >>>>> applied only to a cold stove so was applied to the top, on first = recent >>>>> warm morning this spring, and the increase in heat radiation from = the >>>>> top was dramatic. With just a token fire that Swedish heat mill = was >>>>> spinning full tilt ! >>>>>=20 >>>>> This I assume was a practical demonstration of increased radiation >>>>> from a black surface (Black Body Radiation ?). And all along I had >>>>> imagined that stove blacking was just for appearance. >>>>>=20 >>>>> Yt, DW, Kentville >>>>>=20 >>>>>=20 --Apple-Mail=_E42A442D-5852-492A-8B61-3334541AE499 C