List (cc Crispin)
1; I have fallen behind in responding to Crispin. This is the third in a string, responding to one from Crispin about 2 days ago that started: "Trying to keep up – time is tight:" We are both trying to remove extraneous, finished dialog, so I will insert new numbers for just the ones where I have a follow - up.. 3.1 RWL: >Could one family coke for another (the idea that brought me into TLUD design for wood in 1995). CPP: We need far more than that. The inputs would be about 1 million tons a year. There is no reason for one person to make coke. It would just increase their fuel purchases. If they got their hands on it they would burn it (raw coal). [RWL3.1.2: Disagree. Should depend on the price of coke vs coal. Your BLDD user, who strives to save coke, could have free heating if the price of coke is high enough. For those of us worried about global warming, the making of coke without use of the pyrolysis gases has to be about the most stupid activity around. ] <snip> RWL3.2 >I'd rather do away with coal (and charcoal not put in the ground) altogether - but I hate to think that the coke being used in UB was made badly.] CPP: The present stove makes coke in the early phase of the fire then burns it immediately afterwards. The smoke is from the ignition process. The combustion during coking is quite good. There is a lot of misunderstanding where the smoke comes from. Most NGO’s think it comes from coal during all portions of the fire. [RWL3.2.2: In the TLUD, one has to change the airflow a lot after the char-making phase - or there is a lot of smoke. I presume you would have the same problem. The Phillips stove people solved this with a variable speed fan. Those of us interested in making char for Biochar simply close the system down in one way or another. With a BLDD, you could do the same with a flapper control in the chimney pipe - but I wonder if this second phase inability (or failure) to control air flow isn't also the cause of a lot of smoke in UB. <2 snips> [RWL3.3: I am trying to determine if BLDD and TLUD are different during start-up. Wood and "extremely dense smoke" sure don't have to go together. CPP: I was referring to a conventional ignition. A wood fire is started then coal is placed on it. That puts out the flame for some time, basically. [RWL3.3.2: This doesn't sound like the cause of the smoke is the wood. Any open flame wood fire does the same if you simply dump more on. One of the beauties of a TLUD (and presumably a BLDD) is that one isn't continually controlling power levels with fuel supply. I am pretty sure both of these approaches can start with a tall enough fuel stack to last through a night. In the early days of the stove list, an Iowa corn farmer named Tom talked about heating a barn with a TLUD design which was just a big tall stove pipe, with suitably placed primary and secondary air holes. I can conceive of a housewife getting free heating by selling the resulting coke each morning, RWL3.4 >I have gathered from the comments of John Davies, that coal was always pretty bad until one had turned the coal to coke. CPP: Quite incorrect. The cleanliness of the burn depends heavily on the availability of Hydrogen in the early fire. Later, retained heat can be used to keep the coke burning. RWL3.4.2: John Davies replied two days ago on this point - I thought agreeing with my comment. Maybe we are talking about the traditional approaches to combustion vs TLUDs and BLDDs? John? [RWL3.5 >My hope is that with a controllable fan, one could start the wood fires more readily. Even for a family without electricity, I would guess that a PV-powered fan/blower system would prove cost-effective.] CPP: A chimney is a fan without power. All it requires is some imaginative stove development. In June during training we made very clean starting side draft stoves which are almost as good as TLUD and can be refuelled at any time. [RWL3.5.2: Have to disagree. A fan can put out a lot more air than any (practical) chimney can . Blacksmiths use fans/blowers and bellows for a good reason - to get heat - which is what you said is necessary. I have no problem with side draft (basically not knowing what they are) - but am pretty sure they can't make charcoal - which is my main focus still. I do think BLDD's can make char - and that is my reason for continuing to hope that your BLDD work is successful. Incidentally, Nathaniel Mulcahy does have a continuous feed TLOD design. Nathaniel? I am guessing BLDD makes more sense in UB, but maybe not. <snip> [RWL3.6 : >I have come to believe that the radically different World Stove design (sometime called TLOD) is the cleanest of them all. If Nathaniel is listening - have you ever tried coal? ] CPP: It may or may not work. I have not seen one that could hold 8-10 kg of coal. Coal going in is cold and that is a major issue. Then it gives off huge amounts of volatiles if it is heated rapidly. Then the characteristics of the fuel composition change dramatically. It is unlikely that a heated batch will be manageable. The sidedraft stoves overcome all these problems. [RWL3.6.2: Need Nathaniel again on larger systems - I am pretty sure he has built ones larger than you ask for. The "heated rapidly" is controlled by limiting primary air (hole closures or a fan/blower) in a properly designed TLUD (or TLOD. and presumably BLDD). Can you give a cite on the sidedraft - and are you controlling primary air (and separating from secondary air ) in these side draft designs.? <2 snips on grannie's TLUD and one on storage and ceramic stove pipes in nordic countries. I know that costs are a factor, but still wonder if some energy storage could eliminate the need for all-night operation.> [ [RWL3.7 : Then, I gather that the whole concept of energy efficiency and passive solar is being scrapped for lack of a small stove? Weird reasoning. CPP: Obviously not. Solar was promoted and it is expensive. People earn about $250 a year. People already have stoves when they pull into town on their yak carts. [RWL3.7.2: I misunderstood. I thought we were talking UB's apartment buildings. Is your interest now mostly urban or for the yurts or both? I have been in yurts a few times (Colorado and Kyrgyzstan) but never during a heating season. What is a typical daily consumption of coal in a yurt stove and in a presumably larger apartment stove for a day with 0 degree C outside temperature? The Chinese solar hot water systems (for space heating, not hot water) are quite cheap - and (I'm guessing) might prove more cost effective that PV - which I think are now pretty common for Yurt occupants. Certainly true in Colorado. <snips on straw bale and stove promotion and Chinese solar hot water> RWL3.8 >I see that Mongolia gets its rain in the summer - so Ulaan Baatar (world's coldest capital) might be world's best place for solar heating. CPP Not if you can’t see 100 metres through the thick coal smoke! Little light reaches the ground in many places in Nov-Dec. [RWL3.8.2: Whew. I hadn't that in mind . I'll return to this solar theme as soon as you clean the place up. Good luck with that. (I am reminded that people used to say something similar about London and coal smoke! ) I am afraid that I believe the system will be better off if there can be electric resistance baseboard heating with the coal used in a central station (and that is pretty wasteful, admittedly. Or how about wind in the UB area? I once stayed with a friend in New Mexico who heated his home with wind electricity (and battery storage.) Or imported oil? (Kirk Smith's recommendation to displace wood use at one time. Maybe still. Guessing he would agree on oil being cheap for UB, if you consider ALL the costs.) There must be many epidemiological studies on life times and cancer in UB. How bad? I think there needs to be a study on how cheap coal use is in UB, if one doesn't exist. Thanks again for complete responses. I'm learning a lot. Ron
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