[Stoves] Biogas backpack (Matt Redmond)
Matthew Redmond
mredmond3 at gatech.edu
Mon Jan 9 14:36:05 CST 2012
All,
Max makes a very good point about the potential for explosions caused by
compressible biogas. According to the article (translated using google
translator), compressed tires have been used in Indonesia for biogass
transport. This new method is hailed as a safer method.
-Matt Redmond
On Mon, Jan 9, 2012 at 3:28 PM, <stoves-request at lists.bioenergylists.org>wrote:
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> Today's Topics:
>
> 1. Re: Biogas backpack (Crispin Pemberton-Pigott)
> 2. Re: Biogas backpack (Max Turunen)
> 3. Re: Biogas backpack (Crispin Pemberton-Pigott)
> 4. Re: Biogas backpack (Crispin Pemberton-Pigott)
> 5. Re: Calculation help (Frank Shields)
> 6. Re: Biogas backpack (Ronald Hongsermeier)
> 7. Re: Heat / cook stove - proposed design (Darren)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 9 Jan 2012 13:02:02 -0500
> From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
> To: "'Discussion of biomass cooking stoves'"
> <stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] Biogas backpack
> Message-ID: <052f01cccef8$cd6fcfd0$684f6f70$@gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Dear Ron
>
>
>
> Good to hear from you in the new year.
>
>
>
> >I think you misunderstood the article. The bag is only for transport and
> temporary storage. They take the empty (and some dung) to a biogas
> producer, get it filled and go home to cook with it. It is supposed to be
> about a day's cookin' worth.
>
> I am with David House www.completebiogas.com on this one: it is a
> portable digester with nothing but gas in it! J
>
> He writes, ?It's actually a gas bag, not a digester. Even so, it's an
> excellent innovation, and a worthy addition to the armamentarium, wherever
> it can serve as a means of transport in connection with a large digester
> near any large population.
>
> And as well, from my point of view, it's also a bit ironic, since the very
> sturdy bag, selling for ~$US38, could actually be a digester if it had two
> additional pipes (an inlet and an outlet), and further that since it's
> about a cubic meter in volume, it would produce about a cubic meter of gas
> every day, if fed and kept warm.?
>
> I think David is working on a bag digester himself. The transport of gas
> is interesting. If it turned out to be attractive as a cooking fuel (and
> delivery system) the users would perhaps be convinced to install their own
> systems. I am not convinced that a minibus would accept the gas ?package?
> without fear or charge.
>
> It is a lot lighter than a load of wood and the walking distance might be
> less. I wonder if a tire on a rim might be as good, and could be pumped by
> hand. Will a tire hold a useful volume of gas if hand pumped?
>
> Regards
>
> Crispin
>
>
>
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> ------------------------------
>
> Message: 2
> Date: Mon, 9 Jan 2012 20:20:58 +0200
> From: Max Turunen <maxturunen at gmail.com>
> To: Discussion of biomass cooking stoves
> <stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] Biogas backpack
> Message-ID:
> <CAGO934WHA0qnVZ8+7hbq4RF13OyK26cC67qhRzbVh_4EDD6VYQ at mail.gmail.com
> >
> Content-Type: text/plain; charset="windows-1252"
>
> Jean Pain used old tractor inner tube tires for that... much more gas could
> probably be contained in higher pressure, and even if heavier, such could
> be rolled along... problem: such has much more explosive power and
> potential for accidents.... and leaks do occur and can start to burst to
> flames :s
>
> But.... inner tires could be used for careful transport to various "depot"
> locales in neighbourhoods... route and tire (gas for few days for few
> households ?) kept in safe shaded and distant / blocked / fenced range,
> away from creatures and kids... far enough... with a hose, from which
> portable gas bags could be loaded.... ?
>
> Perhaps usable in some conditions...
>
>
> MaxT
>
> On Mon, Jan 9, 2012 at 8:02 PM, Crispin Pemberton-Pigott <
> crispinpigott at gmail.com> wrote:
>
> > Dear Ron****
> >
> > ** **
> >
> > Good to hear from you in the new year.****
> >
> > ** **
> >
> > *>*I think you misunderstood the article. The bag is only for transport
> > and temporary storage. They take the empty (and some dung) to a biogas
> > producer, get it filled and go home to cook with it. It is supposed to be
> > about a day's cookin' worth.****
> >
> > I am with David House www.completebiogas.com on this one: it is a
> > portable digester with nothing but gas in it! J ****
> >
> > He writes, ?It's actually a gas bag, not a digester. Even so, it's an
> > excellent innovation, and a worthy addition to the armamentarium,
> wherever
> > it can serve as a means of transport in connection with a large digester
> > near any large population.
> >
> > And as well, from my point of view, it's also a bit ironic, since the
> very
> > sturdy bag, selling for ~$US38, could actually *be* a digester if it had
> > two additional pipes (an inlet and an outlet), and further that since
> it's
> > about a cubic meter in volume, it would produce about a cubic meter of
> gas
> > every day, if fed and kept warm.?****
> >
> > I think David is working on a bag digester himself. The transport of gas
> > is interesting. If it turned out to be attractive as a cooking fuel (and
> > delivery system) the users would perhaps be convinced to install their
> own
> > systems. I am not convinced that a minibus would accept the gas ?package?
> > without fear or charge.****
> >
> > It is a lot lighter than a load of wood and the walking distance might be
> > less. I wonder if a tire on a rim might be as good, and could be pumped
> by
> > hand. Will a tire hold a useful volume of gas if hand pumped?****
> >
> > Regards****
> >
> > Crispin****
> >
> > ** **
> >
> > _______________________________________________
> > 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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> >
> > for more Biomass Cooking Stoves, News and Information see our web site:
> > http://www.bioenergylists.org/
> >
> >
> >
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> ------------------------------
>
> Message: 3
> Date: Mon, 9 Jan 2012 13:37:18 -0500
> From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
> To: "'Discussion of biomass cooking stoves'"
> <stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] Biogas backpack
> Message-ID: <053401cccefd$b872c9c0$29585d40$@gmail.com>
> Content-Type: text/plain; charset="us-ascii"
>
> Dear Christa
>
>
>
> It is a great resource and project. Thanks (to whoever) for the budget and
> effort put into it.
>
>
>
> Regards
>
> Crispin
>
>
>
> +++++++
>
>
>
> Thanks Crispin, I had the same idea to post it here, but you were faster.
> Happy New Year.
>
>
>
> To the members of the list who don't know Energypedia yet: it is an online
> resource createdas a Wiki by GIZ . After some years of development as
> company-interal resource, it was opened to the public energy community late
> last year. No registration needed to read.
>
>
>
> Whoever will be at ETHOS: I want to give a brief overview of the features
> found there like the GIZ -HERA cooking energy compendium . If you are not
> going to be in Kirkland or can't wait, feel free to explore on your own:
>
> https://energypedia.info/index.php/GIZ_HERA_Cooking_Energy_Compendium(still
> under development)
>
>
>
> Christa
>
>
>
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> ------------------------------
>
> Message: 4
> Date: Mon, 9 Jan 2012 14:11:49 -0500
> From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
> To: "'Discussion of biomass cooking stoves'"
> <stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] Biogas backpack
> Message-ID: <055901cccf02$8bd86280$a3892780$@gmail.com>
> Content-Type: text/plain; charset="us-ascii"
>
> Given the low mass, it could be stored on the (almost flat) roof of the
> house.
>
>
>
> Regards
>
> Crispin
>
>
>
> >.But.... inner tires could be used for careful transport to various
> "depot"
> locales in neighbourhoods... route and tire (gas for few days for few
> households ?) kept in safe shaded and distant / blocked / fenced range,
> away
> from creatures and kids... far enough... with a hose, from which portable
> gas bags could be loaded.... ?
>
> Perhaps usable in some conditions...
>
>
> MaxT
>
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>
> ------------------------------
>
> Message: 5
> Date: Mon, 9 Jan 2012 12:03:26 -0800
> From: "Frank Shields" <frank at compostlab.com>
> To: <crispinpigott at gmail.com>, "'Discussion of biomass cooking
> stoves'" <stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] Calculation help
> Message-ID: <00f001cccf09$bfee69f0$3fcb3dd0$@compostlab.com>
> Content-Type: text/plain; charset="us-ascii"
>
> Dear Crispin, stovers,
>
> I realize for biomass the difference between J used in evaporation (2256
> j/g) and energy in water at 450c (2854 j/g) is well within the 'noise' of
> biomass fuel so doesn't matter which one we use. And if we all are using
> the
> 2256 value that is what I will do. But it seems since the hydrogen in
> biomass never is in a liquid state or never even water vapor before going
> from solid state to water vapor at ~450 that we should be using 2854
> ((2256
> +(1.72 X 350)). if we think none of it is condensed to release its energy
> before blowing past the pot of water.
>
> At least that is the way I think about it mow.
>
> For the LHV calculation of methane; I see wiki says the HHV is product of
> water in liquid form and LLV is product of water in vapor form - same way
> you calculate biomass. But, of course water is never in the liquid form
> (until it completely condenses at below 100c.). Hydrogen is held by carbon
> or then water vapor at the combustion temp. so I am surprised they
> calculate
> (estimate) it the way they do.
>
> So I will not bother anyone with more questions, will calculate as everyone
> does (subtract energy from water liquid to water vapor) and just think I
> don't understand what really goes on or believe that everyone has just
> agreed to use this method as an estimate to LHV.
>
> Appreciate your help and time.
>
>
> Regards
> Frank
>
>
> Frank Shields
> 42 Hangar Way
> Watsonville, CA 95076
> (831) 724-5244 tel
> (831) 724-3188 fax
> frank at bioCharlab.com
>
>
>
>
>
>
>
>
> -----Original Message-----
> From: stoves-bounces at lists.bioenergylists.org
> [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Crispin
> Pemberton-Pigott
> Sent: Friday, January 06, 2012 7:00 PM
> To: Discussion of biomass cooking stoves
> Subject: Re: [Stoves] Calculation help
>
> Yes that us the correct enthalpy but not all of it is 'lost', by
> definition.
> The definition of 'lost' is taken to mean 'unusable heat', not actual
> losses.
>
> Any gas below 100 C is not going to boil much water so it is considered
> lost
> if below that temperature.
>
> So be careful when calculating the actual heat in something (referenced to
> 0
> C) and losses. Usually LHV is the usable heat above 100 C for most things
> and above 150 for commercial heat exchangers in the USA.
>
> Regards
> Crispin
> -----Original Message-----
> From: "Frank Shields" <frank at compostlab.com>
> Sender: stoves-bounces at lists.bioenergylists.org
> Date: Fri, 6 Jan 2012 14:12:25
> To: 'Discussion of biomass cooking stoves'<stoves at lists.bioenergylists.org
> >
> Reply-To: Discussion of biomass cooking stoves
> <stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] Calculation help
>
> _______________________________________________
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>
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> http://www.bioenergylists.org/
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>
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>
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>
> for more Biomass Cooking Stoves, News and Information see our web site:
> http://www.bioenergylists.org/
>
>
>
>
>
> ------------------------------
>
> Message: 6
> Date: Mon, 09 Jan 2012 21:06:57 +0100
> From: Ronald Hongsermeier <rwhongser at web.de>
> To: Discussion of biomass cooking stoves
> <stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] Biogas backpack
> Message-ID: <4F0B48E1.7060707 at web.de>
> Content-Type: text/plain; charset="utf-8"; Format="flowed"
>
> Dear Crispin,
>
> On 09.01.2012 19:02, Crispin Pemberton-Pigott wrote:
> >
> > Dear Ron
> >
> > Good to hear from you in the new year.
> >
> > *>*I think you misunderstood the article. The bag is only for
> > transport and temporary storage. They take the empty (and some dung)
> > to a biogas producer, get it filled and go home to cook with it. It is
> > supposed to be about a day's cookin' worth.
> >
> > I am with David House |www.completebiogas.com |on this one: it is a
> > portable digester with nothing but gas in it! J
> >
> > He writes, ?It's actually a gas bag, not a digester. Even so, it's an
> > excellent innovation, and a worthy addition to the armamentarium,
> > wherever it can serve as a means of transport in connection with a
> > large digester near any large population.
> >
> > And as well, from my point of view, it's also a bit ironic, since the
> > very sturdy bag, selling for ~$US38, could actually /be/ a digester if
> > it had two additional pipes (an inlet and an outlet), and further that
> > since it's about a cubic meter in volume, it would produce about a
> > cubic meter of gas every day, if fed and kept warm.?
> >
> That may well be, but, not having seen the bag, it may well need some
> additional features apart from two pipes. You'd have to get solid
> materials in and out, etc. Also, I think that his proviso: "...wherever
> it can serve as a means of transport ... large digester ... any large
> population." is overwrought. When compared with walking 10 km with 20 or
> more kg on your head, a 3kg bag is gonna add up to 30 ? pretty quick.
> I'm not dissing the idea of making a digester of that size, just have
> the impression from the relative clause that he is degrading the
> usefulness of the idea unnecessarily.
>
>
>
> > I think David is working on a bag digester himself. The transport of
> > gas is interesting. If it turned out to be attractive as a cooking
> > fuel (and delivery system) the users would perhaps be convinced to
> > install their own systems. I am not convinced that a minibus would
> > accept the gas ?package? without fear or charge.
> >
> I think they limited the size to keep it a relatively manageable size.
> >
> > It is a lot lighter than a load of wood and the walking distance might
> > be less. I wonder if a tire on a rim might be as good, and could be
> > pumped by hand. Will a tire hold a useful volume of gas if hand pumped?
> >
> Even if the walking distance was more, one would not have the same
> fatigue. i think you'd have to work pretty hard to compress a whole m^3
> into anything like a regular tire-- and a tractor tire with rim would be
> more taxing to manage than a load of firewood on one's head. ;-) If this
> was done in cooperation with schools, they could even get the transport
> with larger school children on the way home from school, delivery before
> school, pick up the bag and go home after school. hoping you're doing well.
>
> regards,
> ron
> w
> h
>
>
> > Regards
> >
> > Crispin
> >
> >
> >
> > _______________________________________________
> > 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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> >
> > for more Biomass Cooking Stoves, News and Information see our web site:
> > http://www.bioenergylists.org/
> >
> >
> >
> > No virus found in this message.
> > Checked by AVG - www.avg.com <http://www.avg.com>
> > Version: 10.0.1416 / Virus Database: 2109/4132 - Release Date: 01/09/12
> >
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>
> ------------------------------
>
> Message: 7
> Date: Mon, 09 Jan 2012 20:26:44 +0000
> From: Darren <mail at vegburner.co.uk>
> To: Discussion of biomass cooking stoves
> <stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] Heat / cook stove - proposed design
> Message-ID: <4F0B4D84.2050701 at vegburner.co.uk>
> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
>
> Hello Crispin,
>
> I was using some reclaimed construction timber, pine/conifer, 2"x2" and
> cutting it to short lengths.
>
> I was only opening the lid on top of the fuel hopper to push the fuel
> through under the bridge, to look at what was happening inside or to add
> more fuel. I appreciate that when I've got things set up properly I
> only really want to open it to refuel. I was slightly surprised to find
> the hopper full of smoke - I guess I was expecting the air in the hopper
> to remain static - happy to hear that this is normal.
>
> The wood on the hopper side of the grate was catching alight well. The
> flames did appear to die back significantly when the wood/embers that
> were on the combustion chamber side of the grate had burnt away. I
> guess more testing will tell more.
>
> The original grate is not shakeable, the new one that is sitting on top
> is. I did this so I can vibrate ;) the fuel down the grate. I've now
> got 9cm from grate up to the bridge and this throat is about 10cm wide.
>
> Hopefully I'll get a chance to fire it up with the new grate later in
> the week. I was thinking about experimenting with covering some of the
> back of the grate. I'll cut some metal to fit and try this at some point
> also.
>
> I guess ideally it would run without needing to shake the grate.
> Unfortunately, the way the thing is constructed, lifting the bridge is
> not an easy option. I could more easily lower the grate which would
> provide a bigger gap between grate and bridge and allow for wood to fall
> through more easily, although I guess if this will also effect the heat
> output? Also I guess a steeper grate angle will help.
>
> Best
>
> Darren
>
>
>
>
>
>
> On 09/01/2012 14:52, Crispin Pemberton-Pigott wrote:
> >
> > Dear Darren
> >
> > Thank you for your first burn report. My compliments. People often do
> > not say what happened the first time they light something, but wait
> > until most things are favourable.
> >
> > >Things I noticed.
> >
> > >I put some 5cm x 5cm lumps of wood, then some smaller pieces then
> > some paper in the combustion chamber side of the stove and top lit.
> > This worked well and there was little smoke.
> >
> > So the combustion is going well when the 'burning side' of the stove
> > is loaded and lit. That is a good start.
> >
> > >I threw some more 5cm x 5cm lumps into the fuel hopper.
> >
> > What is the fuel?
> >
> > >Through the window I could see that once the wood in the combustion
> >
> > chamber burnt away the flames died right back down. I opened the
> >
> > hopper up - it was full of smoke.
> >
> > It should be full of smoke. You have a hopper above a fire and the
> > heat from below will be pyrolysing the fuel above where there is no
> > air. If you open the top of the hopper a little, it provides
> > combustion air at a section where there should be no combustion. If
> > you open it enough you will have a hopper fire. The plan was to have
> > the fire in the combustion chamber. Do you get my drift? The hopper
> > opening is primary air supply. It should be coming under the grate
> > both at the bottom of the hopper and under the flaming zone. My
> > understanding is you are trying to establish a self-sustaining
> > (hopper-fed) fire in which case you want there to be some burning at
> > the bottom of the hopper but not in it.
> >
> > >I closed it again, leaving it open a crack and blocking the primary
> > air inlet at the bottom of the stove, which allowed the smoke to get
> > sucked from the hopper, it also reinvigorated the fire.
> >
> > Yes, but with the air being supplied /through/ the fuel which will
> > bring the fire into the hopper. Fire follows air. If the main source
> > of air is through the fuel, the fire will run into the fuel.
> >
> > >I tried pushing the wood through under the bridge so that some was
> > further down the grate. This was difficult as these pieces of wood
> > would readily jam together blocking the throat (space under the
> > ceramic bridge).
> >
> > Is the grate not shakeable? I understand from your later text you have
> > added a grate on top of this grate, and that the upper one can be
> > moved (shaken?) so the implication is the lower one cannot be shaken.
> >
> > Once wood/embers were pushed through under the bridge the fire would
> > again burn vigorously.
> >
> > >I chopped some smaller pieces of wood but found that I still had to
> > push them through under the bridge to get the fire burning with more
> > than a few licks of flames. This was not easy to do.
> >
> > It seems that the fuel dimensions (the 'particle size') will dictate
> > the gap under the ceramic bridge. The grate sliding back and forth
> > would be the easiest way to vibrate (is that the right word?) forward.
> >
> > >When wood and embers were across most of the grate the whole
> > combustion chamber would be full of flames that would disappear into
> > the heat exchanger.
> >
> > That is also OK -- you are looking to have that happen (not quite so
> > vigorously) on a continuous basis, right?
> >
> > >Other points to note. I tried covering/uncovering the secondary air
> > inlets at different times which had a limited effect on the fire. I
> > could see the flames being blown away from the main secondary air
> > inlet at times.
> >
> > If you can see it with your eyes it is definitely working.
> >
> > >My attempt to have secondary air wash the glass apparently did not
> > work well. I guess this may be due to the poor combustion at times -
> > there was noticeable amounts of smoke from the chimney at times. I
> > may attempt to fit some further piping/jetting to send the air more
> > directly at the glass. Wood ash and a little water does clean the
> > glass quite well.
> >
> > It is a bit early to worry about that. You have good combustion when
> > there is fuel in place and the grate is not overloaded. So you have
> > combustion conditions at certain times. You also have a fuel feeding
> > problem which, when you overcome manually, results in a good fire
> > again. These are all steps 'forward'.
> >
> > >The ash [drawer] was not sealing well.
> >
> > That is a problem. If you are not able to direct the air where you
> > want it, the result of leaks is usually a general deterioration of
> > performance because of high excess air. At this stage of your
> > development, just grab some clay from a nearby garden.
> >
> > Here is a stove which has lots of clay on it:
> >
> > Description:
> > imap://
> mail at mail.vegburner.co.uk:143/fetch%3EUID%3E.INBOX.Stoves%3E851?header=quotebody&part=1.1.2&filename=image001.png
> >
> > The cast iron top in that case was so leaky that it was difficult to
> > test the combustion. All joints have clay rubbed into them. The plan
> > was to have a good quality top, so was sealed with clay to simulate
> > one. You can deal with details like leaks later.
> >
> > >The front of the stove is not flat (much of the stove is not flat or
> > square - the scrap metal I used was not all flat and not enough care
> > was taken during the construction of the stove). I set the ash draw
> > so that the gap was under the hopper rather than the combustion chamber.
> >
> > That kinda sounds like the right approach. It's hard to tell where
> > your air is entering, though.
> >
> > >I managed to bend the front of the ash draw today with a hydraulic
> > press so that it now has a reasonable fit against the fire rope/tape
> > that is stuck to the front of the stove.
> >
> > Good.
> >
> > >I guessed that the reason the fire was dying back when the combustion
> > chamber part of the grate was empty was due to excessive primary air
> > passing up through the uncovered (by embers and wood) grate and
> > cooling the combustion chamber burn. (I'm now not entirely sure that
> > this was what was happening)
> >
> > That sounds like the right analysis. To prove it you need to feed the
> > fuel forward as it is needed. If that solves all problems except the
> > fuel feeding (which should be by gravity) you have made major
> > progress. (To feed more fuel the bridge will have to rise.)
> >
> > Yesterday and today I did some more work to try and remedy this...
> >
> > >I made the hopper slope in from 3 sides onto the grate, rather than
> > just one, to direct the wood onto the grate and to give less places
> > for the wood to jam.
> >
> > Tapering a hopper in three directions just about guarantees that the
> > fuel will 'bridge' by which I mean it will create a hollow space and
> > not feed down. Back up one step. A hopper will probably not feed fuel
> > unless it is quite a lot larger than the particle size. For example,
> > if the fuel is 50mm it will not feed into a 200mm funnel. 5mm fuel
> > probably will because it is 1/40^th of the hopper dimensions. Looking
> > a lot of fuel feeding systems, I notice most taper larger, not smaller
> > to prevent bridging. Bridging is also more likely if there is pressure
> > (lots of hopper height) on the tapering portion. Even large systems
> > like boilers have bridging problems.
> >
> > >I made another grate out of 10mm bar that sits on top of the original
> > grate and can be moved backwards and forwards with a handle.
> >
> > Now we are talking....
> >
> > >I did this in the hope that moving the grate will encourage wood
> > under the bridge and across the grate.
> >
> > >Still the moving grate gives more variables to play with. I can also
> > easily lift it higher.
> >
> > You fuel feeding will be easier if the bridge is raised. I was
> > thinking this morning that one thing you can try to prevent the system
> > drawing lots of air through the uncovered (back) portion of the grate
> > is to drop a metal plate over that portion of the grate. Cut a piece
> > of sheet and plunk it on the grate to force the primary air into the
> > lower end of the hopper, without letting in any through the hopper
> > top. That may migrate the fire into the area under the bridge and
> > provide a constant burn. Shaking the grate a little occasionally would
> > feed some fuel forward if the inserted sheet is too narrow front to back.
> >
> > I moved the stove today from my workshop (which is 50 miles away from
> > where I now live)
> >
> > When loading it into my truck I took the doors off.
> >
> > >Despite twice noting that I had done so and telling myself not to
> > forget I unfortunately left the combustion chamber door sat on the bed
> > of the truck and it slid off the truck as I was driving!!!! Luckily I
> > heard the glass break and realised what had happened and went back to
> > get the door.
> >
> > Oh well. Stuff like that happens. Make a ?" observation hole and stick
> > a bolt into it when you are not looking through it. I usually weld a
> > ring on the head of the bolt. It is helpful to have one on top
> > directly over the flames so you can watch the fire develop. It is even
> > possible to take photos through a ? inch hole.
> >
> > Here is a photo of a stove similar in layout to yours, I think, (top
> view)
> >
> > Description:
> > imap://
> mail at mail.vegburner.co.uk:143/fetch%3EUID%3E.INBOX.Stoves%3E851?header=quotebody&part=1.1.5&filename=image003.jpg
> >
> > And here is a photo of the peephole, also top view
> >
> > Description:
> > imap://
> mail at mail.vegburner.co.uk:143/fetch%3EUID%3E.INBOX.Stoves%3E851?header=quotebody&part=1.1.3&filename=image004.png
> >
> > The square is not steel, it is a piece of glass covering the hole. A
> > photo taken through the hole is below. Actually it was a video so I am
> > showing you two frames.
> >
> > Description:
> > imap://
> mail at mail.vegburner.co.uk:143/fetch%3EUID%3E.INBOX.Stoves%3E851?header=quotebody&part=1.1.4&filename=image006.pngDescription
> :
> > imap://
> mail at mail.vegburner.co.uk:143/fetch%3EUID%3E.INBOX.Stoves%3E851?header=quotebody&part=1.1.6&filename=image007.jpg
> >
> > >...I may temporarily fit some plate metal where the glass should be
> > while I await a new piece, although the window has been very useful
> > for assessing what is happening.
> >
> > It certainly has. Without test equipment you are reduced to observing.
> > Good that you noticed the secondary air flow. Good that you have what
> > appears to be clean combustion at least some of the time. You seem
> > only to have a fuel feeding problem. Cover part of the back of the
> > grate -- see what happens. Does the fire move into the fuel piled at
> > the hopper side of the bridge? Does it burn longer without attention?
> > Does the developing fire have a gas path directly to the chimney or
> > are you making the heat exchanger work right from the beginning?
> > Extracting heat to soon and too efficiently kills the draft. 'Failure
> > to thrive'.
> >
> > For the moment, close the secondary air supply because the development
> > of the fire is not dependent on that portion of the combustion. That
> > will put all the draft power into the primary air. At any time you can
> > open the secondary air. If it appears to immediately reduce the
> > combustion rate, you probably have too much. At that point you can
> > start to give it a little at a time. If you really do have excess
> > primary air (which is sounds like you do) you may not need any
> > 'secondary' air at all.
> >
> > It is probably worth chopping up wood into 1 inch chunks to see if it
> > feeds better. But keep the back of the grate partially blocked until
> > you know you have a self-sustaining fire at/under the bridge.
> >
> > Regards
> >
> > Crispin
> >
> >
> >
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