Hi! Me, @David Shouksmith and @Nils Stephenson where discussing that we perceived that the Primus 1010 is better that Primus 158. I feel that the Tilleys i have with wired mesh is also warmer than many other heater with the same type as Primus 158, Svea 25, mm The Primus 158 burns more fuel than 1010. Discussion started here I was searching further and found that the IR is converted to heat in the skin, more specifically IR-B and IR-C. This article : this On this line, it would be interesting to measure the IR production of the different heater to determine the amount of heat they produce. This info is for the skin, what are the radiations what worms upp other stuff? Fir example furniture, air, mm Cheers, Francisc
Any radiation, not necessarily Infrared, could heat / warm up stuffs when the energy of the radiation incident on the object is greater than whatever re-emitted radiation from that object to its surroundings. Radiation of shorter wavelengths has a higher energy levels than those of longer wavelengths like IR, microwaves, radiowaves, soundwaves, etc. Visible light would have higher energy levels than IR of the same intensity. One of the reasons why IR of the same intensity would heat an object more (effectively raising its temperature more) than the equivalent amount of visible light is that most of the visible light's energy received by the object would largely be re-emitted from it, and usually as radiations having somewhat longer wavelengths than the incident light. Whereas, most of the energy by an incident IR radiation would be almost totally absorbed by the object, causing its atoms/molecules to vibrate, etc and effectively raising the temperature within its body. IR mostly or rather, only heats up opaque objects by this 'mechanism'. It doesn't really heat up highly transparent or invisible media or stuffs(air for example). Therefore, its more efficient in this sense. Visible light and UV would heat up transparent media as well. I don't know which Primus model has a higher IR emission or do the Tilleys heat things up better. You'd need to have some measurement devices in place. Some heaters might contain more radiation in the form of visible red or orangy radiations instead of having the bulk of it as invisible IR. It depends a lot on the heating element's emissivities. All of these heaters need to produce the blue flame as a prerequisite, as to be able to heat the elements in the first place. You'd need to consider the fuel consumption of the various heaters. Of course, if they have higher consumption(when working correctly), they would produce a stronger blue flame that could heat the elements more. How much IR is emitted from these elements is also proportional to the magnitude of the primary heat source which, is the blue flame produced by the heater.
Darker colour items also absorb more IR, and conversely re-emit it well. IR meters do exist but they are not givaway prices. Interesting !
Great points of view. Thanks! What I'm thinking is how different materials change the energy what fuels provide into different radiations. If i understand the process until now: Fuel->gas-> blue flame-> +/- mantel for light or heat The lamps use soft mantels to convert more of the energy in visible spectrum. The heaters typ Tilley, Primus 1010 who use metal mantel and create more radiation in the invisible spectrum, or at least i think so. And there are the Primus 158, Burmos, Svea heaters what have a dome few cm above the blue flame and change a part of the energy to invisible spectrum when heated. There are also the heater like Cobra, Optimus 703F, Blue Gaz who have the dome directly above the burner and more of the heat is capture by the dome and the dome is heated more and more (probably) energy is changed into another type of radiation. I'm on the teacks or I'm going wild? Cheers, Francisc
In principle, you can almost assume the understanding is pretty much on the tracks. It would be too elaborative, over-detailed and lengthy if we go to the exact mechanics involved. How much of the desired(IR) radiation being emanated from the respective heaters towards the intended direction/area depends very much on the following: 1. The output ratings of the burners(conversion from chemical to thermal in the form of flames). 2. Size or rather, the effective surface areas of the mantles. 3. The mass, specific heat capacities and thermal conductivities of the mantle materials. This would determine how much thermal energy could be received, absorbed and re-emitted. Closely related would be the way the mantles are shaped or contructed. Thick/coarse, bulbous, cylindrical or fine-meshed? It'd determine the level of incandescence they would attain when heated by the same burners. Simply said, it'd determine if the mantles would glow at dull, cherry, bright red, orangy and so on when heated by the same flame. The higher they go on the colour temperature scale, the greater the portion would be emitted as visible light and lesser in the IR range. 4. The type of materials being used on the mantles. We know well that if they're made of Thorium dioxide, calcium oxide, magnesium oxide or yttrium oxides, etc, a lot of the energy would be converted and radiated in the visible spectrum by either purely blackbody radiation or candoluminescense phenomenon or whatever. As a side info, I have heated the following two oxides using an oxy-LPG torch:- A. Green Chromic oxide, Cr2O3. B. Calcium oxide, CaO. With more or less the same torch settings and heating equal volumes of both oxides, I got the chromic oxide to glow a moderately bright reddish orange while the calcium oxide would attain a highly vivid, nearly white with a tinge of yellow glow. Needless to measure, you can assume that the chromic oxide would have a higher percentage of emitted radiation in the IR range. 5. The design, shape and construction of the heater including their reflectors. Better-designed ones would have less heat loss and higher reflectivities on the desired radiations. Reflectors actually also function to retain, redirect and convert some of the visible radiation into those having longer wavelengths including IR. You should pretty much get the idea.
So really going back to Francis' point the question is about: Does a mesh/gauze heater element transmit more heat (energy) as radiation than a dome type. So to test this ideally we would need to use the identical heater and reflector but just change the element. Have a black painted piece of metal held at a set distance from the element and measure the temperature difference over the same time from a certain temperature.
Yes, you can basically perform such simple tests to find out the effects. As a matter of fact the absorbing target need not even be painted black although that'd accentuate the results in shorter time. That's what really matters for most of us. Ideally, conducted in non-drafty environment. Use identical burners throttled or rather, pressurized to produce similar burner outputs. You can just use a simple temperature probe or thermometer attached to the target instead of costly IR thermographic equipment to evaluate the results. I'd believe the incandescent mesh or element should produce more radiance in the form of sensible heat as compared to the usual soft mantles of similar sizes meant for illumination purposes. Otherwise, there'd be no real need for the production and availability of such elements in the first place. We might as well just be using the regular mantles for both heat and light instead.
I think the comparison is between mesh and perforated dome type of heater element. Black paint to reduce the effects of reflection given the possible differences in spectrum of radiation. Sounds like a plan !
What a great team here. That looks like a good plan. Now just to see how to put in practice /Francisc
For perforated domes/shells, its pretty much similar in concept. They typically produce less incandescence compared to meshed wire-weaves. So its a good start to investigate if the emitted radiation has more IR. That's assuming that the burners are working well and the burn is complete/not sooting up on the inner side.
