Dear Paul Subject: Re: [Stoves] Questions on coal-burning possible TLUD
Following are some comments for your consideration and review....
Chrispin, Thanks for the thoughful response. -- Quoting Crispin Pemberton-Pigott <[email protected]>:Dear Paul Coal is compressed biomass.Yes it is. And biomass is simply sunlight transformed by plants.
They have in common that they are fuels that can release their stored energy.
Let's not be simplistic about this. The Silver is a fossil fuel burner. And coal and biomass are very distinct as fuel, regardless of their origin from sunlight plus C and H and O and a bit more.
Peat, grass, walnut shells, sawdust, wood chips, pellets, cherry pits, etc, are also fuels that can be burned in a TLUD configured stove. The TLUD for the different fuels could probably be configured differently to deal with the size, moisture, and combustion characteristics of various possible fuels. The Silver seems to be a TLUD that was configure for coal
And your information leads me to have little interest. ($200, heavy, high-internal heat would pyrolyze biomass in perhaps irregular ways,
# Heavy, high thermal inertia stoves do have their place. $200 is a very good price for a stove in some areas... wood stoves for room heating sell for as much as $2,500 here. Light, cheap TLUD stoves have their place also.
nobody is using it with biomass - because it is not intended for biomass and the Turkish users have learned that lesson well)
True, and probably nobody is using a Reed TLUD on coal, because it was configured to be portable, for small biomass, for batch operation, and for small batch cooking.
So, let's not get excited as if this recognition of a stove from Turkey will alter the past, present or future of TLUD cookstoves.
Of course not! Dr. Reed's work was, is, and will continue to be very valuable, for the fundamental understanding it brought to "Stove Science". However, the recent awareness of the prior use for the TLUD principle on coal stoves may prompt further optomization of the TLUD system for areas where coal is available as a fuel, and biomass is in short supply.
TLUD stoves (as a NAME, not as a process) have characteristics that go beyond top lit and updraft, and the name refers to devices that use biomass, not fossil fuels.
Recent development and refinement of the TLUD principal has been mainly with them using conventional biomass fuels. To the extent that the "biomass fuels" are now being burned more efficiently using the TLUD principal, there would probably be equivalent benefit for expanded use of TLUD stoves in areas where coal is the preferred fuel.
In my opinion, the "Silver" unit is a very nice distraction from all the work being done on biomass burning TLUDs and other micro-gasifiers.
Well, this is the Stoves List... not the biomass list, and not the Climate Change List. If the TLUD concept can be used advantageously on a stove fueled with coal, then its further use should be encouraged.
I hope that someone spends a few years full-time
with this (and related) coal-burning technologies and makes some great advances. But as it stands now, the discovery or re-discovery of this Turkey product will have minimal impact on the progress needed for the Global Alliance for Clean Cookstoves.
OK... coal as a fuel, has a "black eye", and perhaps the advances made with biomass fueled TLUD's, in terms of the essentials required for best combustion, can now be applied to TLUD's burning coal.
BTW.... have you ever tried coal as a fuel in TLUD's designed for biomass? If so, does it burn reasonably well, or would a TLUD designed for biomass have to be significantly modified to run equally well on coal?
I can hope that someone will show that I am incorrect.
Well, it looks like the TLUD principle was in commercial use on coal about 53 years ago, (1958) and that it was perfected on biomass starting in about 1985. I think you are correct that Dr. Reed led the advancements in biomass TLUD's.
Best wishes, Kevin
Paul -- Paul S. Anderson, PhD Known to some as: Dr. TLUD Doc Professor Phone (USA): 309-452-7072 SKYPE: paultlud Email: [email protected]Good explanation and thanks for the photos. Certainly seems like areasonable heater and stove. It has problems which are easily rectified. The casting quality is really high.1. I will distinguish the "Silver" stove based on it being a coal burner.It should be able to burn any really dense fuel. If it was small enough, itmight do with small pellets.I believe the Silver is substantially larger in diameter of fuel chamberthan is John's. It is taller and larger, for a total of about twice the maximum capacity,however it is not the smallest model. I tested the middle-sized one for the reason that it was the smallest one that has a round hole on top to accept awok.2. In what way would the Silver NOT be accomplishing what we all seekPrice and availability are issues, plus the tweaks that will be need to make it a super stove. It is nearly there. Rumour has it the price is in the $200range....appropriate for Mongolia or even the High Veldt of South Africa wherecoal is abundant Well coal is used if far more places than that. Hundreds of millions of people cook and heat with coal from Eastern Europe to Vietnam.3. This Silver stove needs further study, meaning access to the devices.We want to see and know that the top-ignited fuel does create a migrating pyrolysis front (MPF for short, not as a name).I don't see that micro-classifying it is important. It is just another batch loaded TLUD. It might even work well with dung because it is large enough togenerate meaningful heat.Much more about its emissions needs to be promptly known and, if low, berecognized.The emissions are about 99% lower than the baseline stove, somewhat higher than the (cheaper) GTZ 7.5 which is the only other stove that burns in thatcategory.4. Would this Silver unit function with dry biomass? If not, why not.The main reason would be the overheating of the chamber. I suspect that asit gets so hot there would be over-running gas generation if thermalconductivity turns out to be too high. It is not a big issue in that it isnot advertised or intended as a wood stove anyway.And if successful, why does it take until 2011 to recognize this, but NOTuse it with wood anywhere? You only find what you are looking for, perhaps?Have the 53 years of users been somehow missing such an observation?Well it certainly was not missed in Turkey! Other than the fuel dumping mechanism (which is integrated to the grateshaking mechanism) there is nothing special about it. We have an issue withit (like all batch stoves) which is that it can't be refuelled when it ishot without creating massive smoke. It has to be cooled first. Will peoplewait?? Simply turning it upside down to made a bottom lit downdraft stove wouldcure that and might even reduce emissions further. This disadvantage thereis the cooking efficiency drops. For space heating it is looking like a no-brainer. Regards Crispin---------------------------------------------------------------- This message was sent using Illinois State University RedbirdMail _______________________________________________ The Stoves list has moved to [email protected] - please update your email contacts to reflect the change. Please visit BioEnergy Discussion Lists http://info.bioenergylists.org/ Thank you, Stoves Administrator http://stoves.bioenergylists.org http://info.bioenergylists.org UNSUBSCRIBE HERE; http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org ----- No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1191 / Virus Database: 1435/3390 - Release Date: 01/19/11
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