[Stoves] Sawdust Gasification
Robert Taylor
rt at ms1.hinet.net
Thu May 21 16:23:12 CDT 2015
I seem to remember a few years ago reading--probably on this list--of
sawdust stoves in which the sawdust was packed in around a central
vertical pipe that was removed before top lighting, leaving a hole for
air to come up through.
Robert Taylor
On 2015-05-22 4:33 AM, George Riegg Gambia wrote:
> Hi Tom,
>
> Press it into a briquette - all you need is some kind of binder. We use
> pulped paper but plant binder will do as well.
>
> George
>
> -----Original Message-----
> From: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of
> Tom Reed
> Sent: 21 May 2015 18:12
> To: stoves at lists.bioenergylists.org
> Subject: [Stoves] Sawdust Gasification
>
> Dear List
>
> One of the benefits of the TLUD stove working on wood chips is that it
> produces 20% charcoal, which can be sequestered, removing 38 tons of CO2
> from circulation for each ton of wood gasified (20% due to
> formation of charcoal from the lignin and using the gas from the cellulose
> (renewable) in place of propane, natural gas of coal gas.
>
> If we could gasify sawdust, it would bring another, typically dry, source of
> fuel into the picture. However, the particle size of sawdust does not
> permit TLUD operation. Does anyone have a suggestion of how to gasify
> sawdust?
>
> TOM REED
>
> Thomas B Reed
> 280 Hardwick Rd
> Barre, MA 01005
> 508 353 7841
>
>> On May 20, 2015, at 2:13 PM, stoves-request at lists.bioenergylists.org
> wrote:
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>>
>> Today's Topics:
>>
>> 1. Re: big TLUD (Energies Naturals C.B.)
>> 2. Re: big TLUD (Crispin Pemberton-Pigott)
>> 3. Giving up? ?mobile adam-retort? 4 photos (scda2 at t-online.de)
>> 4. Re: big TLUD (Frank Shields)
>> 5. Re: Giving up? ?mobile adam-retort? 4 photos (Frank Shields)
>> 6. Re: big TLUD (Paul Anderson)
>> 7. Giving up? ?mobile adam-retort? 3 additional drawings
>> (scda2 at t-online.de)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Wed, 20 May 2015 20:57:04 +0200
>> From: "Energies Naturals C.B." <energiesnaturals at gmx.de>
>> To: Discussion of biomass cooking stoves
>> <stoves at lists.bioenergylists.org>
>> Subject: Re: [Stoves] big TLUD
>> Message-ID: <20150520205704.1291c4c6c4b03cf4fa290f12 at gmx.de>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> Hallo "big TLUDers",
>>
>> as I see from the various experiences and comments, the cross section of a
> big TLUD is to some extent limited.
>> That means that in order to build a bigger unit, it has to grow by lenght,
> which in turn must enhance the resistance to the primary air flow. From
> Imberts we know that the relation between fuel size and hearth or throat is
> crucial.
>> There must be enough space left between the particles to allow for a
> adequate air/gas flow.
>> My question: Does anyone have a clue on the matter of fuel size in TLUDs ?
>>
>> Is it possible that larger diameters ask for larger chunks which in turn
> provide more space between them and ideally spread the upflowing air more
> uniformly?
>> Rolf
>>
>>
>>
>> On Sat, 16 May 2015 22:40:14 -0500
>> Paul Anderson <psanders at ilstu.edu> wrote:
>>
>>> Char-makers,
>>>
>>> This good discussion on the Stoves Listserv is being shared with the
>>> Biochar Listserv. Let discussions proceed on each and both and see
>>> what happens.
>>>
>>> It is great to see so much discussion. And Bill's video of his 350
>>> gallon unit is very informative. We await info and photos of the 500
>>> gallon unit he is making now.
>>>
>>> Bill wrote:
>>>> the larger the diameter of the TLUD, the greater the chance that the
>>>> pyrolysis front will not reach the hearth in all areas at the same
>>>> time. If this happens you risk overheating tha hearth if you wait for
>>>> all the fuel to pyrolyse and burn some of the biochar.
>>> I completely agree. And when we report on our actual experience, please
>>> specify the diameter (which is probably more important that the volume).
>>>
>>> Diameters:
>>> 1. A 200 Liter (55 gal) drum or barrel is about 23 inches (58 cm) in
>>> diameter. And that works rather well in the Jolly Roger Ovens (J-ROs)
>>> and similar units.
>>>
>>> 2. From Bill's video, his unit 350 gallon (over 1000 liter) unit is
>>> quite tall and has a diameter about the same as at 55 gal drum. It is
>>> good to see that it works well.
>>>
>>> 3. If I remember correctly, Alex's largest unit was 42 inch diameter
>>> (107 cm) and had problems with uneven descent of the Migratory Pyrolytic
>>> Front (MPF). That matches well with Bill comment that is quoted above.
>>>
>>> So, is Bill's 500 gal unit even taller but still "slender"? And how
>>> well does it work?
>>>
>>> An interesting question is about the possible favorable impact of having
>>> some of the following changes in the big TLUDs:
>>>
>>> A. Impact of a tapering the inside diameter in the lower section. But
>>> as I think more about that, I have my doubts if it will resolve the
>>> irregular MPF issue.
>>>
>>> B. impact of having sensors around the circumference of the TLUD at
>>> perhaps 1 meter vertical distances. And if the temperature (indicating
>>> the MPF) is greater on one side too soon, EITHER
>>> inject addition primary air via tuyers (nozzels) on the colder sides to
>>> hasten the MPF in those areas, OR
>>> inject a bit of water into the area of the hot side to slow its movement
>>> a bit.
>>>
>>> With serious char-making devices such as what Bill has, a relatively
>>> small cost would be the welding of some pipe nipples (each with a screw
>>> on cap) at the appropriate places for the air or water entries (B above)
>>> and where thermocouples could be inserted to check temperatures
>>> including in the center of the cylindrical column of fuel.
>>>
>>> If anyone tries these ideas, please let us all know you progress and
>>> results.
>>>
>>> Paul
>>>
>>> Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
>>> Email: psanders at ilstu.edu
>>> Skype: paultlud Phone: +1-309-452-7072
>>> Website: www.drtlud.com
>>>
>>>> On 5/14/2015 8:20 PM, biocharFIRST . wrote:
>>>> I don't know how big you can build a TLUD. However about three years
>>>> ago I built a 350 gallon TLUD that is working out very well, except
>>>> for the fact that we do not have a use for the sen gas where the TLUD
>>>> is now located at my home. You can see a video at,
>>>> vhttps://www.youtube.com/watch?v=5Kfr4NRhJ0s.
>>>>
>>>> Currently we have almost completed a 500 gallon TLUD that is designed
>>>> to exhaust all of the sen gas down a tube in the center of the tank
>>>> so the heat from the gas can easily be captured for various uses.
>>>> r be uniformly dry, and the larger the diameter of the TLUD, the
>>>> greater the chance that the pyrolysis front will not reach the hearth
>>>> in all areas at the same time. If this happens you risk overheating
>>>> tha hearth if you wait for all the fuel to pyrolyse and burn some of
>>>> the biochar. If you shut off the primary before pyrolysis is complete
>>>> you will get some smoke and some biomass that is not completely
>>>> pyrolysed.
>>>>
>>>> On Thu, May 14, 2015 at 4:46 PM, Crispin Pemberton-Pigott
>>>> <crispinpigott at outlook.com <mailto:crispinpigott at outlook.com>> wrote:
>>>>
>>>> AJH >Yes and/or premixing but why does burning rice hulls tend
>>>> more to the
>>>> blue flame?
>>>>
>>>> Lower volatiles? The carbon/hydrogen ratio is not the same as
>>>> wood. Maybe
>>>> that helps.
>>>>
>>>> Apparently the reactions can be shifted from CO to H2 by using
>>>> different
>>>> catalysts:
>>>> Crispin
>>>>
>>>> From
> http://www.sciencedirect.com/science/article/pii/0141460786900727
>>>> Catalytic gasification of rice hull and other biomass. The general
>>>> effect of
>>>> catalyst.
>>>>
>>>> Abstract:
>>>> Thermochemical decomposition and catalytic conversion of rice hull
>>>> and some
>>>> other cellulosic materials in a fluidized bed reactor containing
>>>> different
>>>> catalysts as the bed material were studied. The use of catalyst
>>>> invariably
>>>> gave gas yields above that of the non-catalyzed gasification
>>>> process and
>>>> also changed the product distribution according to the nature of the
>>>> catalyst. Generally, an acidic catalyst favored the formation of
>>>> carbon
>>>> monoxide and olefins while a supported-metal catalyst increased
>>>> the amounts
>>>> of hydrogen and carbon dioxide. Nickel catalyst yielded as much as
> 60%
>>>> hydrogen at a reaction temperature of 650?C. The gas yield and
> product
>>>> distribution are mainly decided by the properties of the catalyst
>>>> and less
>>>> by the properties of the biomass.
>>>>
>>>> _______________________________________________
>>>> Stoves mailing list
>>>>
>>>> to Send a Message to the list, use the email address
>>>> stoves at lists.bioenergylists.org
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>>>>
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>>>>
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> .org
>>>> for more Biomass Cooking Stoves, News and Information see our web
>>>> site:
>>>> http://stoves.bioenergylists.org/
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> http://www.ithakajournal.com
>>>>
>>>>
>>>> _______________________________________________
>>>> Stoves mailing list
>>>>
>>>> to Send a Message to the list, use the email address
>>>> stoves at lists.bioenergylists.org
>>>>
>>>> to UNSUBSCRIBE or Change your List Settings use the web page
>>>>
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> .org
>>>> for more Biomass Cooking Stoves, News and Information see our web site:
>>>> http://stoves.bioenergylists.org/
>>>>
>>
>> --
>> Energies Naturals C.B. <energiesnaturals at gmx.de>
>>
>>
>>
>> ------------------------------
>>
>> Message: 2
>> Date: Wed, 20 May 2015 15:30:37 -0400
>> From: Crispin Pemberton-Pigott <crispinpigott at outlook.com>
>> To: "'Discussion of biomass cooking stoves'"
>> <stoves at lists.bioenergylists.org>
>> Subject: Re: [Stoves] big TLUD
>> Message-ID: <COL401-EAS266FA6659A75E99A55105E3B1C20 at phx.gbl>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> Dear Rolf
>>
>> I have a general rule (which results from empirical testing) which is that
>> the fuel particle has to be smaller than 1/6th of the diameter of the
>> chamber. At 6 it is iffy - problems abound with the fire going out and
>> difficulty igniting, high excess air, poor potential for secondary air
>> management etc.
>>
>> There is an upper limit too but I am not sure where it is. It is less than
>> 25 and I suspect above 20 is a cause for concern.
>>
>> Packing density is an issue but it is an indicator, but 'the issue'. "The
>> issue" is the superficial and actual velocity of air moving through the
>> system.
>>
>> The numbers are influenced by the temperature of the surrounds so it is
> not
>> as simple as saying 'here are the hard numbers'. When you get to mixing
>> different sizes together you will have to work with the actual air flow
>> rate.
>>
>> Regards
>> Crispin
>> .
>>
>> Hallo "big TLUDers",
>>
>> as I see from the various experiences and comments, the cross section of a
>> big TLUD is to some extent limited.
>> That means that in order to build a bigger unit, it has to grow by lenght,
>> which in turn must enhance the resistance to the primary air flow. From
>> Imberts we know that the relation between fuel size and hearth or throat
> is
>> crucial.
>> There must be enough space left between the particles to allow for a
>> adequate air/gas flow.
>>
>> My question: Does anyone have a clue on the matter of fuel size in TLUDs ?
>>
>> Is it possible that larger diameters ask for larger chunks which in turn
>> provide more space between them and ideally spread the upflowing air more
>> uniformly?
>>
>> Rolf
>>
>>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Wed, 20 May 2015 22:35:24 +0200
>> From: "scda2 at t-online.de" <scda2 at t-online.de>
>> To: stoves at lists.bioenergylists.org
>> Subject: [Stoves] Giving up? ?mobile adam-retort? 4 photos
>> Message-ID: <570151302555cf00cccae11.53491204 at email.t-online.de>
>> Content-Type: text/plain; charset="utf-8"
>>
>> Giving up? ?mobile adam-retort?
>>
>> Dear All,
>> just sharing a few experience with my ?mobile adam-retort?
>> I did test run#5 and I might give up, as it?s too difficult to operate the
> retort in a smokeless way (burning smoke). And without reduced smoke there
> is little sense to operate such a unit near saw mills, carpenter shops in
> suburbs, etc.
>> What?s stunning me: during syngas operation if volatiles are passing
> through the unit, heavy volatiles are leaving chimney. Once I close chimney,
> syngas is overflowing from fire box, and burned syn gas escapes into air in
> kind clear volatiles. OK, you will say: larger ducts, larger diameters of
> channels?
>> But how to get this done with a ?light weight ? unit (~130kg).
>>
>> Photos 1: Overflowing of syn gas from fire box when chimney (~500?C)
> closed. 4th hr of operation.
>> Another phenomena, volatiles are leaving chimney kind of clear volatiles,
> once they get in contact with ambient air- heavy smoke develops.
>> Photo2 : 3rd hour of operation. Shortly before large syn gas production
> starts (chimney ~300?C), fire wood was removed shortly after. AGiP drums
> just serves as a table to hold thermometer. .
>> Photo3: big stress on materials (!), of retort is left open until
> gasification dies, chimney temp rises to ~650?C, Temperature in oil drums
> with wood comes to 600?C also. ( = high quality , high temperature
> charcoal).
>> Efficiency about 30% (dry weight) or ~25% of waste wood in fire box
> counted. Operation about 5 hours (3hrs drying + 2hrs syn gas). ~110kg of
> wood dry weight loaded into 2 oil drums, ~35kg of charcoal received. ~15kg
> of waste wood (dry weight) burnt. Cost of retort ~500US$ (?) mass
> production.
>> Fig. 1 Drawing to explain function. (Unit Is tilted 90? for
> loading/unloading).
>> 22 (chimney), 23 (opening) not needed
>> Fire under 1st oil drum (filled with wood) is producing syngas which is
> burned and is heating 2nd oil drum in caskade effect...
>> Cheers Chris ADAM
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>> ------------------------------
>>
>> Message: 4
>> Date: Wed, 20 May 2015 13:35:37 -0700
>> From: Frank Shields <franke at cruzio.com>
>> To: Discussion of biomass cooking stoves
>> <stoves at lists.bioenergylists.org>
>> Subject: Re: [Stoves] big TLUD
>> Message-ID: <EE6C234A-607E-4C77-BEE8-2119737A8D53 at cruzio.com>
>> Content-Type: text/plain; charset=utf-8
>>
>> Dear Crispin, and Stovers,
>>
>> Interesting topic. And there must be an optimum and way to measure and
> determine what this is.
>> I?m thinking its air channeling (sections of high air movement) that gives
> the problem resulting in un-even air front.
>> In addition to size of particles. Particles must be of a size able to
> ignite from radiant heat from neighboring particles. At stove camp they
> stated a value - something like no more than three times the size of the
> match(?). And that should apply here I would think. We can start with small
> particles on top to light and gradually go to larger particles as the flame
> front moves down? OR does that mean larger particles can be no more than
> three times the smaller particles so all neighbor particles will light. A
> test of particle distribution and uniformity coefficient might be a good
> test.
>> How can we test for channeling?
>> Perhaps: Have air flowing through the system then add pure CO2 and measure
> the CO2 increase at the other end. With even flow there should be a sharp
> increase but with channeling it would be a gradual increase?
>> Regards
>>
>>
>> Frank
>>
>>
>>
>> Frank Shields
>> franke at cruzio.com
>>
>>
>>> On May 20, 2015, at 12:30 PM, Crispin Pemberton-Pigott
> <crispinpigott at outlook.com> wrote:
>>> Dear Rolf
>>>
>>> I have a general rule (which results from empirical testing) which is
> that
>>> the fuel particle has to be smaller than 1/6th of the diameter of the
>>> chamber. At 6 it is iffy - problems abound with the fire going out and
>>> difficulty igniting, high excess air, poor potential for secondary air
>>> management etc.
>>>
>>> There is an upper limit too but I am not sure where it is. It is less
> than
>>> 25 and I suspect above 20 is a cause for concern.
>>>
>>> Packing density is an issue but it is an indicator, but 'the issue'.
> "The
>>> issue" is the superficial and actual velocity of air moving through the
>>> system.
>>>
>>> The numbers are influenced by the temperature of the surrounds so it is
> not
>>> as simple as saying 'here are the hard numbers'. When you get to mixing
>>> different sizes together you will have to work with the actual air flow
>>> rate.
>>>
>>> Regards
>>> Crispin
>>> .
>>>
>>> Hallo "big TLUDers",
>>>
>>> as I see from the various experiences and comments, the cross section of
> a
>>> big TLUD is to some extent limited.
>>> That means that in order to build a bigger unit, it has to grow by
> lenght,
>>> which in turn must enhance the resistance to the primary air flow. From
>>> Imberts we know that the relation between fuel size and hearth or throat
> is
>>> crucial.
>>> There must be enough space left between the particles to allow for a
>>> adequate air/gas flow.
>>>
>>> My question: Does anyone have a clue on the matter of fuel size in TLUDs
> ?
>>> Is it possible that larger diameters ask for larger chunks which in turn
>>> provide more space between them and ideally spread the upflowing air more
>>> uniformly?
>>>
>>> Rolf
>>>
>>> _______________________________________________
>>> Stoves mailing list
>>>
>>> to Send a Message to the list, use the email address
>>> stoves at lists.bioenergylists.org
>>>
>>> to UNSUBSCRIBE or Change your List Settings use the web page
>>>
> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
> .org
>>> for more Biomass Cooking Stoves, News and Information see our web site:
>>> http://stoves.bioenergylists.org/
>>>
>>
>>
>>
>> ------------------------------
>>
>> Message: 5
>> Date: Wed, 20 May 2015 13:43:05 -0700
>> From: Frank Shields <franke at cruzio.com>
>> To: "scda2 at t-online.de" <scda2 at t-online.de>, Discussion of biomass
>> cooking stoves <stoves at lists.bioenergylists.org>
>> Subject: Re: [Stoves] Giving up? ?mobile adam-retort? 4 photos
>> Message-ID: <156C8F05-1CBC-4F8A-8DA0-BCD36F89478D at cruzio.com>
>> Content-Type: text/plain; charset=utf-8
>>
>> I?m wondering if picture #2 is more water vapor than smoke? An in lab
> experiment i did produced the same looking ?smoke? and clouded the room but
> I later thought it water vapor.
>> Frank
>>
>>
>>
>> Frank Shields
>> franke at cruzio.com
>>
>>
>>> On May 20, 2015, at 1:35 PM, scda2 at t-online.de wrote:
>>>
>>> Giving up? ?mobile adam-retort?
>>>
>>> Dear All,
>>> just sharing a few experience with my ?mobile adam-retort?
>>> I did test run#5 and I might give up, as it?s too difficult to operate
> the retort in a smokeless way (burning smoke). And without reduced smoke
> there is little sense to operate such a unit near saw mills, carpenter shops
> in suburbs, etc.
>>> What?s stunning me: during syngas operation if volatiles are passing
> through the unit, heavy volatiles are leaving chimney. Once I close chimney,
> syngas is overflowing from fire box, and burned syn gas escapes into air in
> kind clear volatiles. OK, you will say: larger ducts, larger diameters of
> channels?
>>> But how to get this done with a ?light weight ? unit (~130kg).
>>>
>>> Photos 1: Overflowing of syn gas from fire box when chimney (~500?C)
> closed. 4th hr of operation.
>>> Another phenomena, volatiles are leaving chimney kind of clear volatiles,
> once they get in contact with ambient air- heavy smoke develops.
>>> Photo2 : 3rd hour of operation. Shortly before large syn gas production
> starts (chimney ~300?C), fire wood was removed shortly after. AGiP drums
> just serves as a table to hold thermometer. .
>>> Photo3: big stress on materials (!), of retort is left open until
> gasification dies, chimney temp rises to ~650?C, Temperature in oil drums
> with wood comes to 600?C also. ( = high quality , high temperature
> charcoal).
>>> Efficiency about 30% (dry weight) or ~25% of waste wood in fire box
> counted. Operation about 5 hours (3hrs drying + 2hrs syn gas). ~110kg of
> wood dry weight loaded into 2 oil drums, ~35kg of charcoal received. ~15kg
> of waste wood (dry weight) burnt. Cost of retort ~500US$ (?) mass
> production.
>>> Fig. 1 Drawing to explain function. (Unit Is tilted 90? for
> loading/unloading).
>>> 22 (chimney), 23 (opening) not needed
>>> Fire under 1st oil drum (filled with wood) is producing syngas which is
> burned and is heating 2nd oil drum in caskade effect...
>>> Cheers Chris ADAM<IMG_5050 overflow.JPG><IMG_5023 smoke1.JPG><IMG_5039
> glow.JPG><detail drawing1
> mobile.JPG>_______________________________________________
>>> Stoves mailing list
>>>
>>> to Send a Message to the list, use the email address
>>> stoves at lists.bioenergylists.org
>>>
>>> to UNSUBSCRIBE or Change your List Settings use the web page
>>>
> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists
> .org
>>> for more Biomass Cooking Stoves, News and Information see our web site:
>>> http://stoves.bioenergylists.org/
>>>
>>
>>
>>
>> ------------------------------
>>
>> Message: 6
>> Date: Wed, 20 May 2015 16:03:41 -0500
>> From: Paul Anderson <psanders at ilstu.edu>
>> To: Discussion of biomass cooking stoves
>> <stoves at lists.bioenergylists.org>
>> Subject: Re: [Stoves] big TLUD
>> Message-ID: <555CF6AD.5070501 at ilstu.edu>
>> Content-Type: text/plain; charset=windows-1252; format=flowed
>>
>> Rolf,
>>
>> Fuel size is related to the dwell-time (time the fuel is exposed to the
>> heat). Tom Reed says it takes about one hour of exposure to pyrolyze
>> through about one inch (2.5 cm) of wood FROM ONE SIDE. So think of
>> radius of the fuel or its smallest dimension.
>>
>> And the TLUD height (which relates to the duration of the operation)
>> will give some indication of the available time.
>>
>> 1. So, you could have a 2 inch smallest-dimension piece of fuel near
>> the top of the fuel pile in a one hour of operation TLUD. But the same
>> piece of wood if inserted vertically would have an hour of heat at the
>> top but less than 30 minutes or even only 15 minutes for the end that is
>> near the bottom. The bottom part will be off-gasing (giving smoke) if
>> it is removed when the majority of the pyrolysis has completed.
>> Waiting for that piece to pyrolyze in a functioning unit will result in
>> the loss of char that is burning to give the heat for pyrolysis.
>>
>> Vertical pieces of wood work very well, but it is good to have a bottom
>> layer of smaller pieces.
>>
>> 2. The other big variable is the control of the two air supplies. The
>> ability to SHUT DOWN the primary air is extremely important, and widely
>> overlooked. Ideally, the MPF (Migratory Pyrolytic Front) will descend
>> rather uniformly. But if it does not (and this problem increases in
>> likelihood in larger TLUDs), pyrolysis and char making can be kept
>> somewhat under control if the primary air is severely restricted. Keep
>> the HEAT (not the fire itself) inside the fuel chamber and the off-gases
>> will be created, the fire at the top (burning the gases) can be
>> sustained and also controlled for minimal smoke even though the fire
>> inside the TLUD has dropped to the bottom of the fuel chamber. Not a
>> perfect run cycle, but probably some reasonable char production
>> (compared with letting the fire race away inside the fuel chamber).
>>
>> 3. The ability to supplement (increase) the air flows (both of them,
>> but separately) is a major factor for control and for reducing the
>> dependence on uniformity of fuel sizes. Yesterday, in a TLUD of two
>> small barrels, the final stages of a 45 minute operation had too much
>> pyrolysis occurring, giving lots of flames (shooting 4 inches above the
>> 3 foot chimney) and some visible black smoke. Instead of cutting back
>> the primary air, I used a portable blower (with a 12 V DC motorcycle
>> battery) to increase only the secondary air, and the smokiness
>> disappeared and the flames were only half way up the chimney.
>>
>> NOTE: This gave great heat supply, but for a shorter time period than
>> if I had cut back on the primary air (giving more time for pyrolysis).
>>
>> Paul
>>
>> Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
>> Email: psanders at ilstu.edu
>> Skype: paultlud Phone: +1-309-452-7072
>> Website: www.drtlud.com
>>
>>> On 5/20/2015 2:30 PM, Crispin Pemberton-Pigott wrote:
>>> Dear Rolf
>>>
>>> I have a general rule (which results from empirical testing) which is
> that
>>> the fuel particle has to be smaller than 1/6th of the diameter of the
>>> chamber. At 6 it is iffy - problems abound with the fire going out and
>>> difficulty igniting, high excess air, poor potential for secondary air
>>> management etc.
>>>
>>> There is an upper limit too but I am not sure where it is. It is less
> than
>>> 25 and I suspect above 20 is a cause for concern.
>>>
>>> Packing density is an issue but it is an indicator, but 'the issue'.
> "The
>>> issue" is the superficial and actual velocity of air moving through the
>>> system.
>>>
>>> The numbers are influenced by the temperature of the surrounds so it is
> not
>>> as simple as saying 'here are the hard numbers'. When you get to mixing
>>> different sizes together you will have to work with the actual air flow
>>> rate.
>>>
>>> Regards
>>> Crispin
>>> .
>>>
>>> Hallo "big TLUDers",
>>>
>>> as I see from the various experiences and comments, the cross section of
> a
>>> big TLUD is to some extent limited.
>>> That means that in order to build a bigger unit, it has to grow by
> lenght,
>>> which in turn must enhance the resistance to the primary air flow. From
>>> Imberts we know that the relation between fuel size and hearth or throat
> is
>>> crucial.
>>> There must be enough space left between the particles to allow for a
>>> adequate air/gas flow.
>>>
>>> My question: Does anyone have a clue on the matter of fuel size in TLUDs
> ?
>>> Is it possible that larger diameters ask for larger chunks which in turn
>>> provide more space between them and ideally spread the upflowing air more
>>> uniformly?
>>>
>>> Rolf
>>>
>>> _______________________________________________
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>>
>>
>>
>> ------------------------------
>>
>> Message: 7
>> Date: Wed, 20 May 2015 23:13:07 +0200
>> From: "scda2 at t-online.de" <scda2 at t-online.de>
>> To: stoves at lists.bioenergylists.org
>> Subject: [Stoves] Giving up? ?mobile adam-retort? 3 additional
>> drawings
>> Message-ID: <491227133555cf8e32dbc15.21279557 at email.t-online.de>
>> Content-Type: text/plain; charset="utf-8"
>>
>>
>> If someone wants to go into it (additional drawings)
>>
>> Fig.2 front view
>> Fig.3 side view
>> Fig.4 top view
>>
>> Part list:
>>
>> List of Reference:
>>
>> 1, 2, one, two or more containers
>> 3, base plate
>> 4, closure
>> 5, Low chamber-frame
>> 6, fireplace
>> 7, passage opening
>> 8 sheet metal strip
>> 9, channel
>> 10, chimney pipe
>> 11, upper Case
>> 12, frame for unrolling
>> 13, quarter-circular rounding
>> 14, pivot point
>> 15, tilt direction
>> 16, opening underside container
>> 17, smoke-burning zone by secondary air
>> 18, pipe to connect the flue gases between modules SKiP
>> 19, passage to connect the secondary air between modules SKiP
>> 20, passage to connect the chimney gases in the upper case between
> modules SKiP
>> 21, passage opening for modular design SKiP
>> 22, chimney pipe with Bye-pass function and closing SKiP
>> 23, passage opening with bye-pass function and closure SKiP
>>
>>
>>
>>
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>> ------------------------------
>>
>> Subject: Digest Footer
>>
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>>
>> ------------------------------
>>
>> End of Stoves Digest, Vol 57, Issue 19
>> **************************************
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